Optimum design and accurate control of the internal structure of the laser target materials remain an important goal for various laser physics experiments, especially for generating high flux photon and neutron beams. The low-density material is considered to be one of the most difficult for X-ray study due to its high transparency and imperceptible contrast. To produce clear visualization of foam containing sparse structures we used a high-quality monochromatic X-ray beam of synchrotron radiation source PETRA-III at DESY. The X-ray beam parameters allow tomographic scanning with application of phase contrast retrieval algorithms. A series of 3D images of foam-suspended glass microsphere inside the plastic cylinder were obtained with the quality high enough to observe the internal structure and to visualize uniformity, displacement and surface roughness on both sides of the microsphere. The main object under investigation was a CH-plastic capillary including 10 mg/cc CHO-foam with the centered glass microsphere. The results of this work demonstrate that tomographic visualization based on a high quality X-ray radiation and phase contrast analysis is an effective and useful technique for development of new laser targets containing structured low density materials.

The radiation stability of polymer test objects fabricated by direct laser writing is studied. The two groups of 6 cubes (50×50×50 μm3) were printed on a common silicon substrate. 6 cubes were irradiated with X-rays in the synchrotron radiation beam (12 keV, 1010 photons/mm2/s), the other 6 kept non-irradiated for the reference. In each group, the fabrication parameters (laser power and slicing step) were uniformly varied from cube to cube. Each irradiated cube was exposed with the dose of 1013 X-ray photons. The calibration of this dose in the radiological units (Gy) was carried out using the tissue-equivalent thermoluminescent detectors (TLD-800). The corresponding exposition dose was estimated as 30 kGy for each cube. The radiation effects were evaluated by Raman spectroscopy and by morphological changes observed with the raster electron microscope. The primary radiation effect appears in the essential increase of the polymerization degree with consuming carbon-carbon double bonds in favor of the polymer cross-linking. Only one cube of 6 has changed the size and shape due to this effect, while the others retained the initial shape. Morphological changes are connected with the improper fabrication parameters (laser power and slicing step). Properly fabricated objects withstand the X-rays of the synchrotron radiation beam.

The pulse duration in short-pulse schemes for Self-Amplified Spontaneous Emission Free Electron Lasers (SASE FELs) is limited by the FEL coherence time. A recently proposed concept allows to overcome the coherence time barrier and to get much shorter pulses. When the lasing part of an electron bunch is much shorter than the coherence time, one can suppress the radiation in the long main undulator while preserving microbunching within that short lasing slice. Then a short radiation pulse is produced in a relatively short radiator. A possible suppression method, an excessive reverse undulator taper, is discussed and illustrated numerically in this paper. We also performed first experimental tests of this method at the soft X-ray FEL user facility FLASH. The measured pulse duration approaches 1 fs (FWHM) at the wavelength of 5 nm.

Recently, considerable work has been directed at development of a ultra-compact X-ray free-electron laser based on emerging techniques in high field cryogenic acceleration, with attendant dramatic improvements in electron beam brightness, and state-of-the-art concepts in beam dynamics, magnetic undulators, and X-ray optics. A full conceptual design of a 1 nm XFEL with a length and cost over an order of magnitude below current XFELs has resulted from this effort. This instrument has been developed with an emphasis on permitting exploratory scientific research in a wide variety of fields in a university setting. Concurrently, compact FELs are being urgently developed for use as an instrument to enable next generation chip manufacturing through use as a high flux, few-nm lithography source. This new role suggests consideration of XFELs to addressed urgently emerging demands in this sector, as identified by recent national need studies, for new radiation sources aimed at chip manufacturing: a coherent hard X-ray source which enables frontier metrology methods. Indeed, it has been shown that one may use coherent X-rays to perform 10 nm-class resolution surveys of macroscopic, cm-scale structures such as chips, using ptychographic laminography. As the XFEL is a very promising candidate for realizing such methods, we present here an analysis of the issues and likely solutions associated with extending the UCXFEL to harder X-rays (above 7 keV), much higher fluxes and levels of coherence, and methods of applying such a source for ptychographic laminography to micro-electronic device measurements. We discuss the development path to move the concept to rapid realization of a transformative FEL-based application, outlining FEL and metrology system challenges.

We put forward a co-axial pump(optical)-probe(X-rays) experimental concept and show performance of the optical component. A Bessel beam generator with a central 100 micrometers-diameter hole (on the optical axis) was fabricated using femtosecond (fs) laser structuring inside a silica plate. This flat-axicon optical element produces a needle-like axial intensity distribution which can be used for the optical pump pulse. The fs-X-ray free electron laser (X-FEL) beam of sub-1 micrometer diameter can be introduced through the central hole along the optical axis onto a target as a probe. Different realisations of optical pump are discussed. Such optical elements facilitate alignment of ultra-short fs-pulses in space and time and can be used in light-matter interaction experiments at extreme energy densities on the surface and in the volume of targets. Full advantage of ultra-short 10 fs X-FEL probe pulses with fs-pump(optical) opens an unexplored temporal dimension of phase transitions and the fastest laser-induced rates of material heating and quenching. A wider field of applications of fs-laser-enabled structuring of materials and design of specific optical elements for astrophotonics is presented.

We developed a versatile 100 Hz laser system based on negatively and positively chirped pulse amplification. The few-cycle output provides pulses with 7.1 fs and 0.25 mJ, while the power output supports 26 fs pulses with 50 mJ. The energy as well as the pulse duration stability of the system is below 1%, while the pointing stability is within 25% of the diffraction limited spot size. We also show applications in high repetition rate target development and preparation for a laser-generated X-ray source for industrial CT imaging.

SLM Additive Manufacturing has demonstrated great potential for aerospace applications when structural elements of individual design and/or complex shape need to be promptly supplied. 3D-printable AlSi10Mg (RS-300) alloy is widely used for the fabrication of different structures in aerospace industry. The importance of the evaluation of residual stresses that arise as a result of complex 3D-printing process thermal history is widely discussed in literature, but systematic assessment remains lacking for their magnitude, spatial distribution, and comparative analysis of different evaluation techniques. In this study we report the results of a systematic study of residual stresses in a 3D-printed double tower shaped samples using several approaches: the contour method, blind hole drilling laser speckle interferometry, X-ray diffraction, and Xe pFIB-DIC micro-ring-core milling analysis. We show that a high level of tensile and compressive residual stresses is inherited from SLM 3D-printing and retained for longer than 6 months. The stresses vary over a significant proportion of the material yield stress. All residual stress evaluation techniques considered returned comparable values of residual stresses even regardless of dramatically different dimensional scales from millimeters for the Contour Method down, laser speckle interferometry and XRD and down to small fractions of a mm (70 μm) for Xe pFIB-DIC ring-core drilling. The use of residual stress evaluation is discussed in the context of optimizing the printing strategy to enhance the mechanical performance and long-term durability.

Background : Newly generated cardiomyocytes (NGC) concur to recovery of human myocarditis. However, Methods: We retrospectively assessed NGC in 213 consecutive patients with endomyocardial biopsy denoting acute myocarditis, with normal coronaries and valves. Tissue samples were processed for histology (H&E), immunohistochemistry for the evaluation of inflammatory infiltrates, immunostaining for alpha-sarcomeric-actin, junctional connexin-43, Ki-67, phosphorylated STAT3 (p-STAT3) and Western Blot (WB) for HMGB1. Frozen samples were analyzed with polymerase chain reaction (PCR) for cardiotropic viruses. Controls included 20 normal surgical biopsies. Results: NGCs were defined as small myocytes (diameter < 10 µm) with nuclear positivity to Ki-67 and p-STAT3, positive immunostaining for cytoplasmic α-sarcomeric actin and connexin 43. Their number/mm2 in relation with age and pathway of integration were evaluated. NGCs crossed the membrane and grew integrated within the empty necrotic myocytes. NGC mean diameter was 6.6 ± 3.34 vs 22.5 ± 3.11 µm adult cells; their number, in comparable LVEF, was 86.3 ± 10.3/mm2 in patients between 10 and 40 years; 50.4 ±13.8/mm2 in those between 41 and 60; 15.1 ± 5.7/ mm2 in those between 61 and 80; control NGC mean diameter was 0.2± 0.2/mm2. PCR was positive for viral genomes in 16% of cases; NGCs were not statistically different in viral and non-viral myocarditis. WB analysis revealed a higher expression of HMGB1 in myocarditis compared to myocardial controls. Conclusions: NGCs are constantly recognizable in acute human myocarditis. Their number declines with age. Their integration within necrotic myocytes consents preservation of cardiac structure and function.

In (Semigroup Forum 77: 325-338, 2008) Mahmoudi M. and Renshaw J. solved a study that covers of cyclic $S$-acts over monoids. This article is an attempt to initiate the covers of finitely generated $S$-acts. We give a necessary and sufficient condition for a monoid to have the properties that $n$-generated $S$-acts have strongly flat covers, Condition $(P)$ covers and projective covers. The main conclusions extend some known results. We show also that Condition $(P)$ covers of finitely generated $S$-acts are not unique, unlike the situation for strongly flat covers. Additionally, we demonstrate that the property of Enochs' $\mathcal{X}$-precover of $S$-act $A$, where $\mathcal{X}$ denotes a class of $S$-acts that are closed under isomorphisms.

A Micro holes in a diamond are presented by using a homemade femtosecond (fs) Yb:KGW laser. An fs laser source was used emitting pulse duration of 230 fs at 1030 nm wavelength, whereas the spot size amounted to 8.9 μm. Parameters like pulse energy, and pulse number were varied over a wide range in order to evaluate their influence both on the micro hole geometry like hole diameter, circularity, taper angle, and on the drilling quality. Hourglass-shaped micro holes whose diameters decrease and increase again after a certain depth have important applications. The results demonstrate the feasibility of extending the drilling of an hourglass-shaped hole in a diamond sample, which has similar diameters at the hole entrance (92 μm) and exit (95 μm), but a much smaller diameter (28 μm) at a certain waist section inside the hole.

Polymeric Intraocular lenses (IOLs) are vital for restoring vision following cataract surgery and for correcting refractive errors. Despite technological and medical advancements, challenges persist in achieving optimal vision and preventing complications. Surface modifications aim to mitigate the risk of posterior capsule opacification (PCO), while pre-operative measurements aid in selecting suitable IOLs. However, individualized solutions are lacking and there is a clear demand for the development of fully customised IOL surfaces. We employ laser micromachining technology for precise modifications via ablation on PMMA and Acrylic IOLs, using femtosecond (fs), nanosecond (ns), and diode continuous wave (CW) lasers, at wavelengths ranging from near-ultraviolet to infrared. Characterization reveals controlled ablation patterning, achieving feature sizes from as small as 400 nm to several micrometers. Regular and confocal Micro-Raman spectroscopy revealed alterations of the IOL materials' structural integrity for some pattering cases, thus affecting the optical properties, while these can be minimised by proper selection of micromachining conditions. The results suggest the feasibility of accurate IOL patterning, which could offer personalized vision correction solutions, based on relevant corneal wavefront data, thus surpassing standard lenses, marking a significant advancement in cataract surgery outcomes.

Nondestructive determination of the neutron irradiation induced embrittlement of nuclear reactor pressure vessel steel is a very important and recent problem. In the frame of the so called NOMAD project, funded by the Euratom research and training program, novel nondestructive electromagnetic testing methods were applied for inspection of irradiated reactor pressure vessel steel. In this review the most important results of this project are summarized. Different methods were used and compared with each other. Measurement results were compared with the destructively determined ductile to brittle transition temperature (DBTT) values. Three magnetic methods: 3MA (micromagnetic, multiparameter, microstructure and stress analysis), MAT (magnetic adaptive testing) and Barkhausen noise technique (MBN) were found as the most promising techniques. The results of these methods were in good confidence with each other. Good correlation was found between the magnetic parameters and the DBTT values. The basic idea of the NOMAD project is to use a multi-method/multi-parameter approach and to focus on their synergies that allows to recognise the side effects therefore supressing them at the same time. Different types of Machine Learning (ML) algorithms were tested in competition and their performances were evaluated. The important outcome of the ML technique is that not only one, but several different ML techniques could reach required precision and reliability, i.e. to keep the DBTT prediction error lower than +/-25°C threshold, which was previously not possible for any of the NDE methods as single entities. A calibration/training procedure was carried out on the merged outcome of testing methods with excellent results to predict transition temperature, yield strength and mechanical hardness for all investigated materials. Our results, achieved within NOMAD project can be useful for the future potential introduction of this (and in general, any) nondestructive evolution method.

We propose a computer-generated hologram method for near-eye virtual reality and augmented reality 3D display. A 3D object located near the holographic plane is projected onto a projection plane to obtain a plurality of projected images with different angles. The hologram is calculated by superposition of projected image convolution with a specific PSF through the interference of reference wave with object wave. Holographic 3D display systems with LED as illumination, 4f optical filtering system and lens as eyepiece for near-eye VR display and HOE as combiner for near-eye AR display are designed. The results show that the proposed method is about 38 times faster than the conventional point cloud method. The proposed method is flexible to produce speckle noise free high-quality VR and AR images with efficient focus and defocus capabilities.

In this work, zinc oxide (ZnO) thin film has been fabricated on glass substrate using pulse laser ablation (PLA) technique. The effect of laser pulses of 1000, 1500, 2000 pulses at laser energy 700 mJ as well as, laser energy of 600, 700, and 800 mJ at fixed laser pulses of 1500 pulse, with methanol as a solvent on the structural properties of prepared films using XRD, SEM and EDX. XRD results revealed that the ZnO thin films have hexagonal structure with polycrystalline in nature with preferred orientation of (002). Crystalline size was increased with the increasing of the pulses and at energy of 700 mJ and pulse of 1500 pulse seemed nanostructure like tree leaf. In addition, narrow FWHM and no phase change have been observed in all cases. SEM images showed that for all cases the films were homogenous with some island and cluster then cracking started to obtain with the increasing of increase the pulse number. EDX analysis showed that the prepared films were free of defects and contaminations.

The recent growth of wearable medical device technology in the form of fitness trackers, smart watches, smartphone apps, and patient monitoring systems has created people-generated health data (PGHD) that may benefit medical science with large amounts of continuous real-world data. The prevalence of these devices speaks to their broad popularity and user-friendliness and may lead us one day to a more fully “connected healthcare system.” Meanwhile, data security, confidentiality, and privacy issues have emerged in these hackable systems. Despite the promise of anonymized data, data can sometimes be re-identified, but even without that step, data breaches may reveal information (name, address, date of birth, social security number, and so on) sufficient for identity theft. Clinicians are often asked about the utility and value of wearable devices or monitors, but most are unaware that data from these systems may be transmitted, stored, and even sold without the user’s specific knowledge. Despite the confidentiality of medical information, cybersecurity surrounding wearables and monitors remains relatively lax, making them comparatively easy targets for cyber-villains. It is also important that efforts be taken to make PGHD more secure, since medical data may have great value to telehealth applications and AI-physician assistants. Clinicians should take an active role in informing patients about both risks and benefits of wearables and similar devices.

With the view toward enlivening the Chinese automobile market, this work seeks to develop a framework to reveal the tastes of Chinese car users from online user-generated content (UGC) and identify future product improvement orientation. We construct an importance-satisfaction gap analysis (ISGA) model based on sentiment analysis technique. Specifically, a novel unsupervised word-boundary-identified algorithm for the Chinese language is used to extract domain professional feature words and a set of sentiment scoring rules is constructed. By matching feature-sentiment word pairs, we calculate car users' satisfaction with different attributes based on the rules, and weigh the importance of attributes using TF-IDF method, which lay the statistic foundation for our ISGA model. We also take time into account and further analyze the ISGA model, aiming to provide new insight into the changing tastes of Chinese car users so as to suggest correct design positioning and resource allocation. The final evaluation results show that the method proposed in this paper, which integrates Chinese word-boundary-identified algorithm and sentiment lexicon matching rules, is well supported.

Transcription factors (TFs) are proteins that recognize specific DNA fragments in order to decode the genome and ensure its optimal functioning. TFs work at the local and global scales by specifying cell type, cell growth and death, cell migration, organization and timely tasks. We investigate the structure of DNA-binding motifs with the theory of finitely generated groups. The DNA ‘word’ in the binding domain -the motif- may be seen as the generator of a finitely generated group Fdna on four letters, the bases A, T, G and C. It is shown that, most of the time, the DNA-binding motifs have subgroup structure close to free groups of rank three or less, a property that we call ‘syntactical freedom’. Such a property is associated to the aperiodicity of the motif when it is seen as a substitution sequence. Examples are provided for the major families of TFs such as leucine zipper factors, zinc finger factors, homeo-domain factors, etc. We also discuss the exceptions to the existence of such a DNA syntactical rule and their functional role. This includes the TATA box in the promoter region of some genes, the single nucleotide markers (SNP) and the motifs of some genes of ubiquitous role in transcription and regulation.

The present work proposes a novel manufacturing technique based on the combination of Laser Metal Deposition, Laser Beam Machining and Laser Polishing processes for the complete manufacturing of complex parts. Therefore, the complete process is based on the application of a laser heat source both for the building of the preform shape of the part by additive manufacturing and for the finishing operations. Their combination enables to manufacture near-net-shape parts and afterwards, remove the excess material via laser machining, which has resulted to be capable of eliminating the waviness resulting from the additive process. Besides, surface quality is improved via laser polishing to reduce the roughness of the final part. Therefore, conventional machining operations are eliminated, what results in a much cleaner process. In order to validate the capability of this new approach, the dimensional accuracy and surface quality of the resulting parts are evaluated. The process has been validated on an Inconel 718 test part, where a previously additively built up part has been finished by means of laser machining and laser polishing.

Based on PVDF (piezoelectric sensing techniques), this paper attempts to study the propagation law of shock waves in brittle materials during the process of three-wavelength laser irradiation of polysilicon, and discusses the formation mechanism of thermal shock failure. The experimental results show that the vapor pressure effect and the plasma pressure effect in the process of pulsed laser irradiation lead to the splashing of high temperature and high density melt. With the decrease of the laser wavelength, the laser breakdown threshold decreases and the shock wave is weakened. Because of pressure effect of the laser shock, the brittle fracture zone is at the edge of the irradiated area. The surface tension gradient and surface shear wave caused by the surface wave are the result of coherent coupling between optical and thermodynamics. The average propagation velocity of laser shock wave in polysilicon is 8.47×103m/s, and the experiment has reached the conclusion that the laser shock wave pressure peak exponentially distributes attenuation in the polysilicon.

Natural ventilation in a building is an effective way to achieve acceptable indoor air quality. Ventilation dilutes contaminants such as bio-effluents generated by occupants, substances emitted from building materials, and water vapor generated by occupants' activities. In a building that requires heating and cooling, adequate ventilation is crucial to minimize energy consumption while maintaining healthy indoor air quality. However, measuring the actual magnitude of the ventilation rate, including infiltration through the building envelope and airflow through building openings, is not always feasible. In this study, the occupant-generated carbon dioxide (CO2) tracer gas decay method was applied to estimate the ventilation rates in an office room in Seoul, South Korea, from summer to winter. Using the method, real-time ventilation rates can be calculated by monitoring indoor and outdoor CO2 concentrations without injecting a tracer gas. 145mm-diameter circular openings on the fixed glass were used for natural ventilation in the test room. As a result, firstly, the indoor CO2 concentrations were used as an indicator to evaluate how much the indoor air quality deteriorated when all the windows were closed in an occupied office room compared to international standards for indoor air quality. Moreover, we found out the estimated ventilation rates varied depending on various environmental conditions, even with the same openings for natural ventilation. Considering the indoor and outdoor temperature differences and outdoor wind speeds as the main factors influencing the ventilation rates, we analyzed how they affected the ventilation rates in different seasons of South Korea. When the wind speeds were calm, the temperature difference played as a factor that influences the estimated ventilation rates. On the other hands, when the temperature differences were low, the wind speed was the primary factor. This study raises awareness about the risk of poor indoor air quality in office rooms that could lead to health problems or unpleasant working environments. This study presents an example of estimating the ventilation rates in an existing building. In the same way, the ventilation rate in an existing building can be simply estimated while using the building as usual, and appropriate ventilation strategies for the building can be determined to maintain desired indoor air quality.

Holographic projection is a simple projection because it enlarges or reduces reconstructed images without using a zoom lens. However, one major problem associated with this projection is the deterioration of image quality as the reconstructed image enlarges. In this paper, we propose a time-division holographic projection, in which the original image is divided into blocks and the holograms of each block are calculated. Using a digital micromirror device (DMD), the holograms were projected at high speed to obtain the entire reconstructed image. However, the holograms on the DMD need to be binarized, thereby causing uneven brightness between the divided blocks. We correct this by controlling the displaying time of each hologram. Additionally, combining both the proposed and noise reduction methods, the image quality of the reconstructed image was improved. Results from the simulation and optical reconstructions show we obtained a full-color reconstruction image with reduced noise and uneven brightness.

A fast calculation method for the full parallax high-resolution hologram is proposed based on the elemental light field image (EI) rendering. A 3D object located near the holographic plane is firstly rendered as multiple EIs with a pinhole array. Each EI is interpolated and multiplied by a divergent sphere wave and interfered with a reference wave to form a hogel. Parallel acceleration is used to calculate the high-resolution hologram because calculation of each hogel is independent. A high-resolution hologram with the resolution of 20,0000×20,0000 pixels is calculated only within 8 minutes. Full parallax high-resolution 3D displays are realized by optical reconstructions.

Laser machining by ultra-short (sub-ps) pulses at high intensity offers high precision, high throughput in terms of area or volume per unit time, and flexibility to adapt processing protocols to different materials on the same workpiece. Here we consider the challenge of optimization for high throughput: how to use the maximum available laser power and larger focal spots for larger ablation volumes by implementing a fast scan. This implies the use of high-intensity pulses approaching ∼PW/cm2 at the threshold where tunnelling ionization starts to contribute to overall ionization. A custom laser micromachining setup was developed and built to enable high speed, large area processing and easy system reconfiguration for different tasks. The main components include laser, stages, scanners, control system, and software. Machining of metals such as Cu, Al, or stainless steel, and fused silica surfaces at high-fluence and high-exposure doses at high scan speeds up to 3 m/s were tested for the fluence scaling of ablation volume, which was found to be linear. Modified surfaces are color-classified for their appearance, which is dependent on surface roughness and chemical modification. Such colour-coding can be used as a feedback parameter for industrial process control.

Directional dithering of a laser beam potentially limits the detection accuracy of a laser triangulation displacement probe. A theoretical analysis indicates that the measurement accuracy will linearly decrease as the laser dithering angle increases. To suppress laser dithering, a laser triangulation displacement probe with laser beam pointing control, which consists of a collimated red laser, a laser beam pointing control setup, a receiver lens, and a charge-coupled device, is proposed in this paper. The laser beam pointing control setup is inserted into the source laser beam and the measured object and can separate the source laser beam into two symmetrical laser beams. Hence, at the angle at which the source laser beam dithers, the positional averages of the two laser spots are equal and opposite. Moreover, a laser dithering compensation algorithm is used to maintain a stable average of the positions of the two spots on the imaging side. Experimental results indicate that with laser beam pointing control, the standard variance of the fitting error decreases from 0.3531 to 0.0100, the repeatability accuracy can be decreased from ±7mm to ±5 μm, and the nonlinear error can be reduced from ±6 %FS to ±0.16 %FS.

Transparent and high-hardness materials have become the object of wide interest. Most notably, it concerns technical glasses and crystals. A notable example is a sapphire – one of the most rigid materials having impressive mechanical stability and good optical properties. Nonetheless, using this material for 3D micro-fabrication is not straightforward due to its brittle nature. On the microscale, selective laser etching (SLE) technology is an appropriate approach for such media. Therefore, we present our research on c-cut crystalline sapphire microprocessing by using femtosecond radiation-induced SLE. Here we demonstrate a comparison between different wavelength radiation (1030 nm, 515 nm, 343 nm) usage for modification inscription and various etchants (Hydrofloridic acid, Sodium Hydroxide, Potassium Hydroxide and Sulphuric and Phosphoric acid mixture) comparison. We show that regular SLE etchants such as Hydrofluoric acid or Potassium Hydroxide are unsuitable materials for selective sapphire laser etching. Meanwhile, a 78% sulphuric and 22% phosphoric acid mixture at 270°C temperature is a good alternative for this process. We present the changes in the material after the separate processing steps. Finally, a protocol for advanced sapphire structure formation and a few exemplary structures are presented.

This study explores the public library service evaluation domain through user-generated content on Google Maps, highlighting digital feedback's significant yet underexplored potential in understanding public library patronage across Taiwan's six major cities. Utilizing a mixed-methods research design, this study integrates Google Maps review content analysis with Social Network Analysis to delineate public perceptions and identify areas for service enhancement in public libraries. It innovatively leverages personal experiences extracted from over 60,000 Google Maps reviews to evaluate public library services in cities such as Taipei, New Taipei, Taoyuan, Taichung, Tainan, and Kaohsiung. The research taps into the National Library of Taiwan's National Library Statistics System to provide a robust analysis of library performance and user satisfaction, offering a novel perspective by emphasizing user-centric feedback from Google Maps as a primary data source. This approach provides quantitative data on library usage and geographic distribution and enriches our understanding of the qualitative experiences of library users. In analyzing the keywords from Google Maps reviews of public libraries, we categorize and interpret these under the three core LibQUAL+ dimensions—Affect of Service, Information Control, and Library as Place. The findings expose variances in perceived service quality among the cities, with Kaohsiung and Taichung receiving the highest accolades for service satisfaction. Simultaneously, the study identifies potential areas for improvement, particularly in cities with lower satisfaction ratings like Taipei. This personalized feedback illustrates the intimate relationship between public libraries and their communities, offering invaluable insights for policymakers and library management to enhance service delivery and user experience.

Sentence stimuli pervade psycholinguistics research. Yet limited attention has been paid to the automatic construction of sentence stimuli. Given their linguistic capabilities, this study investigated the efficacy of ChatGPT/AI tools in generating sentence stimuli. In three psycholinguistic experiments, this study examined the acceptability and validity of AI-formulated auditory sentences and written sentences in two languages: English and Arabic. Participants gave English AI-generated stimuli similar to or higher acceptability ratings than human-composed stimuli, but the opposite was observed for Arabic AI-generated stimuli. The validity of AI-developed stimuli relied on the study design, with only Experiment 2 demonstrating the target psycholinguistic effect (L1/L2 morphosyntactic prediction). These results highlight the promising role of AI as a stimuli developer which could facilitate psycholinguistic research and increase its diversity. Implications for psycholinguistic research were discussed.

The Korean Pathfinder Lunar Orbiter (KPLO)-MAGnetometer (KMAG) consists of three triaxial fluxgate sensors (MAG1, MAG2, and MAG3) to measure the magnetic field around the Moon. The three sensors are mounted in the order of MAG3, MAG2, and MAG1 inside a 1.2 m long boom away from the satellite body. Before it arrived on the Moon, we compared the magnetic field measurements taken by DSCOVR and KPLO in the solar wind to verify the measurement performance of the KMAG instrument. We found that there were artificial disturbances in the KMAG measurement data, such as step-like and spike-like disturbances, which were produced by the spacecraft body. To remove spacecraft-generated disturbances, we applied a multi-sensor method, employing the gradiometer technique and principal component analysis and using KMAG magnetic field data and confirmed the successful elimination of spacecraft-generated disturbances. This indicates that the multi-sensor method is able to clean the magnetic field data measured onboard the KPLO.

Introduction: Breast ptosis is characterized by the downward nipple-areola complex displacement below the inframammary fold. Breast ptosis is associated with ageing and its concomitant changes in estrogen levels in conjunction with other factors like macromastia, weight loss, pregnancy, and both alcohol and tobacco consumption products affecting breast tissue architecture impacting the well-being and quality of life in the affected women. This study aimed to evaluate the efficacy of a novel mastopexy technique in patients with breast ptosis. Methods: A longitudinal, non-experimental, analytical study was done in a cohort of 231 women diagnosed with breast ptosis treated with a novel low-level multifrequency laser-assisted mastopexy assessing sternal notch-to-nipple distance (SNND) and breast ptosis status according to the Regnault system at the first, second, and third postoperative month. Additionally, the incidence and nature of compli-cations within the first 30 days post-surgery were evaluated according to the Clavien-Dindo system. Results: The breast ptosis proportion significantly changed across the three-month fol-low-up period from 100% to only 10% (all ptosis grade I). 90% of the patients achieved the non-ptosis grade according to the Regnault system (p

Laser in situ keratomileusis (LASIK) is the gold standard in the surgical correction of refractive errors on the cornea. It entails the creation of a superficial hinged corneal flap by a femtosecond laser, ablation of the underlying stromal bed by an excimer laser, and reposition of the flap. The corneal flap can be build in a 2-dimension (2D) fashion with tapered edges, or in a 3-dimension (3D) fashion, with angled sidecut. The latter reduces the risk of flap dislocation and infiltration of epithelial cells. This retrospective study compares with optical coherence tomography 3D and 2D flaps, and respective intra- and early post-operative complications. Four hundred consecutive eyes were included, 200 for each group. In the 3D group, the mean edge angle was 92°. The procedure was in average 5.2 seconds slower in the 3D group (p=0). Non visually significant flap folds were found in 13 eyes of the 2D group and in 7 eyes of the 3D group (p= 0.17). An intracorneal opaque bubble layer induced by laser photodisruption was more commonly observed in the 3D group (9 eyes vs. 2; p=0.03). In conclusion, the creation of a LASIK flap by a 3D-femtosecond laser cut was safe and effective.

This study explores the innovative use of CO2 laser technology in frenuloplasty, a significant shift from traditional methods like scalpel surgery or electrocautery, towards a minimally invasive approach. The research involved 15 patients aged 25 to 50, undergoing frenuloplasty with a CO2 laser system equipped with a 7-inch defocused handpiece, set at 20Hz and 0.3W. This method diverges from conventional laser techniques, focusing on controlled laser passes combined with manual traction to elongate the fibrous tissue of the frenulum. The results demonstrated that the CO2 laser technique allowed for a precise and progressive modification of the frenulum, significantly reducing the risks of hemorrhage and secondary in-tention fibrosis. The healing process was notably expedited, with patients reporting satisfactory outcomes within a two-week period. Statistically significant improvements were observed in pa-tient-reported outcomes, as evidenced by the increases in the Short Form Health Survey (SF-12) scores, with the mean Physical Component Summary (PCS) score rising from 32.5 to 47.5 and the mean Mental Component Summary (MCS) score from 39.3 to 52.3 (p < 0.001 for both). The study concludes that CO2 laser frenuloplasty is an effective and safe technique, offering sub-stantial benefits in terms of reduced healing time and enhanced patient satisfaction. The signifi-cant improvements in SF-12 scores underscore the positive impact on patient quality of life, ad-vocating for the broader application of this technique in clinical practice. Further research is warranted to explore its potential in a wider clinical context.

Laser therapy devices (LTDs) operating with near-infrared laser light are increasingly being used in sports medicine. For several reasons the users cannot evaluate whether or not such devices emit laser beams according to the specifications provided by the manufacturer and the settings of the device. In this study the laser beams from two different LTDs that can be used in sports medicine were thoroughly characterized by measuring the emitted power, pulse shapes and lengths, and spatial intensity distributions using professional, high-fidelity laser measurement technology. This was repeated for three units of each LDT independently to distinguish problems of individual units from potential intrinsic instrument design errors. The laser beams from the units of one LTD agreed with the settings at the device, with the measured average power for these units being within 3.3% of the set power. In contrast, the laser beams from the units of the other LTD showed large deviations between the settings and the actual emitted light. This device came with three laser diodes that could be used independently and simultaneously. The average power differed greatly between the units as well as between the laser diodes within each unit. Some laser diodes emitted essentially no light, which could lead to a lack of treatment of patients. Other laser diodes emitted much more power than set at the device (up to 230%) that could result in skin irritations or burnings of patients. These findings indicate a need for better standardization and consistency of therapeutic laser light sources.

We report on the study of ultrafast laser-induced plasma expansion dynamics in a gas microjet. To this purpose, we focused femtosecond laser pulses on a nitrogen jet produced through a homemade De Laval micronozzle. The laser excitation leads to plasma excitation with a characteristic spectral line emission at 391 nm. By following the emitted signal with a detection system based on an Intensified Charge-Coupled Device (ICCD) we captured the two-dimensional spatial evolution of the photo-excited nitrogen ions with a temporal resolution on the nanosecond time scale. We fabricated the micronozzle on fused silica substrate by femtosecond laser micromachining. This technique enables high accuracy and three-dimensional capabilities, thus providing an ideal platform for developing glass-based microfluidic structures for application to plasma physics and ultrafast spectroscopy.

The development of printing technologies has enabled the realization of electric circuit fabrication on flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag) nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of laser focal position and intensity. Based on these methods, the flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated with functional operations.

Deck inclination and vertical displacements are among the most important technical parameters to evaluate the health status of a bridge and to verify its bearing capacity. Several methods, both conventional and innovative, are used for structural rotations and displacement monitoring; no one of these does allow, at the same time, precision, automation, static and dynamic monitoring without using high cost instrumentation. The proposed system uses a common laser pointer and image processing. The elastic line inclination is measured by analyzing the single frames of a HD video of the laser beam imprint projected on a flat target. For the image processing, a code was developed in Matlab® that provides instantaneous rotation and displacement of a bridge, charged by a mobile load. An important feature is the synchronization of the load positioning, obtained by a GNSS receiver or by a video. After the calibration procedures, a test was carried out during the movements of a heavy truck maneuvering on a bridge. Data acquisition synchronization allowed to relate the position of the truck on the deck to inclination and displacements. The inclination of elastic line was obtained with a precision of 0.01 mrad. The results demonstrate the suitability of the method for dynamic load tests, control and monitoring of bridges.

Carbon fiber-reinforced polymer (CFRP), noted for its outstanding properties including high specific strength and superior fatigue resistance, is increasingly employed in aerospace and other demanding applications. This study investigates the interactions between CFRP composites and high-energy lasers (HEL), with continuous wave laser powers reaching up to 120 kW. A novel automated sample exchange system, operated by a robotic arm, minimizes human exposure while enabling a sequence of targeted laser tests. High-speed imaging captures the rapid expansion of a plume consisting of hot gases and dust particles during the experiment. The research significantly advances empirical models by systematically examining the relationship between laser power, perforation times, and ablation rates. It demonstrates scalable predictions for the effects of high-energy laser radiation. Detailed examination of the damaged samples, both visually and via micro-focused computed X-ray tomography, offers insights into heat distribution and ablation dynamics, highlighting the anisotropic thermal properties of CFRP. Compression-after-impact (CAI) tests further assess the residual strength of the irradiated samples, enhancing the understanding of CFRP’s structural integrity post-irradiation. Collectively, these tests improve the knowledge of the thermal and mechanical behavior of CFRP under extreme irradiation conditions. The findings not only contribute to predictive modeling of CFRP's response to laser irradiation but also enhance the scalability of these models to higher laser powers, providing robust tools for predicting material behavior in high-performance settings.

Plant cells' ability to withstand abiotic stress is strongly linked to modifications in their mechanical characteristics. Nevertheless, the lack of a workable method for consistently tracking plant cell mechanical properties severely restricts our comprehension of the mechanical alterations in plant cells under stress. With Polyethylene Glycol (PEG6000), we created a drought-like environment, and we used the Double Resonator Piezoelectric Cytometry (DRPC) method to dynamically and non-invasively track changes in the stress (ΔS) created and viscoelasticity (storage modulus G' and loss modulus G") of protoplasts and suspension cells of rice during drought stress. The findings demonstrate that, rice suspension cells and protoplasts react mechanically differently to 5%–15% PEG6000 stress, implying distinct resistance mechanisms. However, neither of them can withstand 25% PEG6000 stress, they respond mechanically similarly to 25% PEG6000 stress. The results of DRPC are further corroborated by the morphological alterations of rice cells and protoplasts observed under an optical microscope. To sum up, the DRPC technique functions as a precise cellular mechanical sensor and offers novel research tools for the evaluation of plant cell adversity and differentiating between the mechanical reactions of cells and protoplasts under abiotic stress.

Our recent work has focused on the application of infinite group theory and related algebraic geometric tools in the context of transcription factors and microRNAs. We were able to differentiate between “healthy" nucleotide sequences and disrupted sequences that may be associated with various diseases. In this paper, we extend our efforts to the study of messenger RNA metabolism, showcasing the power of our approach. We investigate (i) mRNA translation in prokaryotes and eukaryotes, (ii) polyadenylation in eukaryotes, which is crucial for nuclear export, translation, stability, and splicing of mRNA, (iii) miRNAs involved in RNA silencing and post-transcriptional regulation of gene expression, and (iv) the identification of disrupted sequences that could lead to potential illnesses. To achieve this, we employ (a) infinite (finitely generated) groups fp, with generators representing the r+1 distinct nucleotides and a relation between them [e.g., the consensus sequence in the mRNA translation (i), the poly(A) tail in item (ii), and the miRNA seed in item (iii)], (b) aperiodicity theory, which connects “healthy groups" fp to free groups Fr of rank r and their profinite completion F^r, and (c) the representation theory of groups fp over the space-time-spin group SL2(C), highlighting the role of surfaces with isolated singularities in the character variety. Our approach could potentially contribute to the understanding of the molecular mechanisms underlying various diseases and help develop new diagnostic or therapeutic strategies.

Laser Powder Bed Fusion (LPBF), as a transformative technology in the field of additive manufacturing, offers unprecedented design flexibility and material efficiency. This review paper delves into the latest advancements in LPBF technology and the various alloys used in the process, including titanium alloys, aluminum alloys, nickel-based superalloys, steel alloys, copper alloys, and high-entropy alloys. For each alloy category, we discuss their specific applications, performance characteristics, and challenges faced in LPBF usage. The paper discusses important technological breakthroughs, including innovations in laser systems, scanning strategies, and in-situ monitoring technologies, which have enhanced the precision and reliability of LPBF.

To investigate the associated mechanisms concerning collagen and the expression of apoptosis-related proteins in porcine skin injuries induced by laser exposure, pig skin was treated with a 1064 nm laser. The healing process of the laser-treated areas, alterations in collagen structure, and changes in apoptosis were continuously observed and analyzed from 6 hours to 28 days post-irradiation. On the 28th day following exposure, wound contraction and recovery were notably sluggish in the medium-high dose groups, displaying more premature and delicate type III collagen within the newly regenerated tissues. The collagen density in these groups was roughly 37-58% of that in the normal group. Between days 14 and 28 after irradiation, there was a substantial rise in apoptotic cell count in the forming epidermis and granulation tissue of the medium-high dose group, in contrast to the normal group. Notably, the expression of proapoptotic proteins bax, caspase-3, and caspase-9 surged significantly 14 days after irradiation in the medium-high dose groups and persisted at elevated levels on the 28th day. During the later stage of wound healing, the augmented apoptotic cell population and insufficient collagen generation in the newborn skin tissue of the medium-high dose groups were closely associated with delayed wound recovery.

An experimental platform for laser-driven ion (sub-MeV) acceleration and potential applications was recently commissioned at the HiLASE laser facility. The auxiliary beam of the Bivoj laser system operating at GW peak power (~10 J in 5-10 ns) and 1-10 Hz repetition rate enabled a sta-ble production of high-current ion beams of multiple species (Al, Ti, Fe, Si, Cu, Sn). The pro-duced laser-plasma ion sources were fully characterized against the laser intensity on target (1013-1015 W/cm2) by varying the laser energy, focal spot size, and pulse duration. This al-lowed to provide accurate scaling laws of the maximum ion energy for the different target ma-terials investigated. Such experimental scaling laws are presented for the first time in the inves-tigated laser intensity range and for ns-class laser pulses, and allow to provide a qualitative in-terpretation of the laser-plasma interaction underpinning physics, thus to tune the main features of the accelerated ion beams (energy, temperature, and current). Such a detailed study was facil-itated by the large amount of data acquired at high repetition rate (1-10 Hz) provided by the Bivoj laser system. The versatility and tuneability of such high-repetition-rate laser-plasma ion sources are of po-tential interest for multidisciplinary user applications.

There is increasing interest in the application of near-infrared (NIR) laser light for the treatment of various musculoskeletal disorders. The present study thoroughly examined the physical characteristics of laser beams from two different laser therapy devices that are commercially available for the treatment of musculoskeletal disorders. Then, these laser beams were used to measure the penetration depth in various biological tissues from different animal species. The key result of the present study was the finding that for all investigated tissues, most of the initial light energy was lost in the first one to two millimeters, more than 90% of the light energy was absorbed within the first ten millimeters, and there was hardly any light energy left after 15 – 20 mm of tissue. Furthermore, the investigated laser therapy devices fundamentally differed in several laser beam parameters that can have an influence on how light is transmitted through tissue. Overall, the present study showed that a laser therapy device that is supposed to reach deep layers of tissue for treatments of musculoskeletal disorders should operate with a wavelength between 800 nm and 905 nm, a top-hat beam profile, and it should emit very short pulses with a large peak power.

A wide variety of applications require high peak laser intensity in conjunction with a narrow spectral linewidth. Typically, injection-locked amplifiers have been employed for this purpose, where a continuous wave oscillator is amplified in a secondary external resonant amplifier cavity using a pulsed pump laser. In contrast, here we demonstrate a setup that combines a CW Ti:sapphire oscillator and pulsed amplifier in a single optical cavity, resulting in a compact system. Dichroic beam combination of blue wavelength semiconductor diodes and the green wavelength of a Nd:YAG laser allowed the simultaneous excitation of the Ti:sapphire crystal by both continuous-wave and pulsed pump sources. A linewidth of &lt;2MHz is achieved in continuous wave operation, while the linewidth increases to about 10MHz in the combined CW + pulsed mode with a pulse duration of 73ns. A peak pulse intensity of 0.2kW is achieved, which should enable efficient single-pass second harmonic generation in a nonlinear crystal.

Direct laser writing based on non-linear 3D nanolithography (also known as 3D laser lithography, 3DLL) is a powerful technology to manufacture polymeric micro-optical components. However, practical applications of these elements are limited due to the lack of knowledge of their optical resilience and durability. In this work, we employ 3DLL for the fabrication of bulk (i.e. fully filled) and woodpile structures out of different photopolymers. We then characterize them using S-on-1 laser induced damage threshold (LIDT) measurements. In this way, quantitative data of LIDT values can be collected. Furthermore, this method permits to gather damage morphologies. The results presented in this work demonstrate that LIDT values depend on the material and the geometry of the structure. Bulk non-photosensitized hybrid organic-inorganic photopolymer SZ2080 structures are found to be the most resilient with a damage threshold being of 169±15 mJ/cm².

The aim of this study was to investigate the possibility of a freeform fabrication of porous ceramic parts through selective laser sintering (SLS). SLS was proposed to manufacture ceramic green parts because this additive manufacturing technique can be used to fabricate three-dimensional objects directly without a mold, and the technique has the capability of generating porous ceramics with controlled porosity. However, ceramic printing has yet fully achieved its 3D fabrication capabilities without using polymer binder. Except for the limitation of high melting point, brittleness and low thermal shock resistance from instinct ceramic material properties, the key hurdle lies on very poor absorptivity of oxide ceramics to fiber laser which is widely installed in the commercial SLS equipment. An alternative solution to overcome the poor laser absorptivity via improving material compositions was presented in this study. The positive effect of carbon additive on the absorptivity of silica powder to fiber laser will be discussed. To investigate the capabilities of the SLS process, 3D porous silica structures were successfully prepared and characterized.

Volumetric modification of transparent materials by femtosecond laser pulses is successfully used in a wide range of practical applications. The level of modification is determined by the locally absorbed energy density, which depends on numerous factors. In this work, it is shown experimentally and theoretically that, in a certain range of laser pulse energies, the peak of absorption of laser radiation for doughnut-shaped (DS) pulses is several times higher than for Gaussian ones. This makes the DS pulses very attractive for material modification and direct laser writing applications. Details of the interaction of laser pulses of Gaussian and doughnut shapes with fused silica obtained by numerical simulations are presented for different pulse energies and compared with the experimentally obtained data. The effect of absorbed energy delocalization with increasing laser pulse energy is demonstrated for both beam shapes while, at relatively low pulse energies, the DS beam geometry provides a stronger local absorption compared to Gaussian one. Implications of a DS pulse action on post-irradiation material evolution are discussed based on thermoelastoplastic modeling.

It is well known that the effect of laser irradiation on the blood causes a change in the shape of red blood cells and an increase in their activity, especially in low-level laser therapy (LLLT). The aim of this study was to identify the ability of erythrocytes to deform when exposed to a blue laser.24 laboratory rats were exposed to blue laser in the gingival region of the lower jaw daily for 5 minutes over 3 days. The blue laser possessed a power of 0.5 W and was operated using a con-tactless approach, the dynamic technique in continuous wave mode, and an uninitiated fiber. A blood sample was taken from the lateral vein of the tail before the LLLT, on the first, second, third, and fifth days. The samples were stained, and cytometry was conducted. The exposure to blue laser caused a significant increase in the number of dome-shaped deformable erythrocytes in the blood of laboratory rats (p

Background: Introduction of new technologies in the management of oral disease has revolutionized treatment approaches, offering less invasive options and improved patient outcomes. Among oral cavity diseases, sialolithiasis is the most common disorder of the salivary glands. It involves the formation of calculi or stones within the salivary ducts, primarily affecting the submandibular gland due to its tortuous duct and the alkaline nature of its saliva. In particular, Laser-assisted techniques have shown significant promise in enhancing the precision and safety in the management of sialolith removal. This article aims to present a case report and also explores the scientific evidence supporting these innovative methods, highlighting their benefits and limitations in clinical practice.; Methods: The research was conducted using PubMed and Scopus search engines with a combination of relevant keywords, including laser, laser-assisted, laser treatment in combination with sialolith, sialolith removal, and sialoadenectomy. Selected articles were carefully reviewed to identify studies reporting data on the effectiveness of laser-assisted sialolith removal; Results: The results of the literature review indicate a growing interest in the application of Diode Laser and CO2, with evidence suggesting improved clinical outcomes and reduced postoperative pain compared to traditional methods; Conclusions: Although lasers offer enhanced safety and reduced morbidity and bleeding, which ensures optimal visibility, their high cost and the need for specialized training are limitations. Further randomized clinical trials and longer follow-up studies are needed to better evaluate their use in sialolith removal.

Crystallization of glass through conventional thermal annealing in a furnace is a well-understood process. However, crystallization by femtosecond (fs) laser brings another dimension to this process. The pulsed nature of the irradiation necessitates a reevaluation of parameters for optimal crystallization and to understand the particularities in the case of using fs laser. This includes adjusting the laser pulse energy, the repetition rate, and the writing speed to either initiate nucleation or achieve substantial crystal growth. Therefore, a key challenge to this work is to establish reliable calculations for understanding the relation of the size of the crystallized region with respect to an ongoing transition (e.g., solid-to-solid, liquid-to-solid), and accounting for the aforementioned laser parameters. In this context and based on previous work, we simulate a temperature distribution (in space and time) to model the thermal treatment at any point in the glass. By setting the condition that the temperatures are between the glass transition and melting temperature, we can deduce the crystallized region size to be compared with experimental observations. For that purpose, the knowledge of the beam width at the focal point and of the absorbed beam energy fraction are critical inputs that were extracted from experiments found in the literature. After that, management of the crystallization process and the width of the crystallization line can be achieved according to pulse energy e.g. crystallite size, and also the effect of the scanning speed can be understood. Among the main conclusions to highlight, we disclose the laser conditions that determine the extent of the crystallized area and deduce that it is never interesting to increase the pulse energy too much but rather the repetition rate for uniform crystallized line.

Luminescent carbon dots (CDs) were locally synthesized in the core of CYTOP fibers using IR femtosecond laser direct writing (FLDW), a one-step simple method serving as a post-treatment of the genuine fiber. This approach enables the creation of several types of modifications such as ellipsoid voids. The CDs and photoluminescence (PL) distribute at the periphery of the voids. The PL spectral properties were studied through Excitation Emission Matrix in the visible range and excitation/emission spectrum in UV/visible range. Our finding reveals the presence of at least 3 distinct luminescent species, facilitating a broad excitation range extending from UV to green, and light emission spanning from blue to red. The average laser power and dose influence the quantity and ratio of these luminescent CD species. Additionally, we measured the spatially resolved lifetime of the luminescence during and after the irradiation. We found longer lifetimes at the periphery of the laser-induced modified regions and shorter ones closer to the center, with a dominant lifetime ~ 2ns. Notably, unlike many other luminophores, these laser-induced CDs are insensitive to oxygen, enhancing their potential for display or data storage applications.

Background: this interventional pilot study aimed to evaluate the short-term (3 years) efficacy of focal laser ablation (FLA) in treating the index lesion of low-intermediate risk prostate cancer, along with assessing the safety of the procedure (ClinicalTrials.gov ID NCT04045756). Methods: forty patients aged between 46 and 86 with histologically proven organ-confined prostate cancer and low to intermediate progression risk were included. FLA was performed under percutaneous fusion magnetic resonance/ultrasound guidance in a Day Hospital setting under local anesthesia. Patients underwent regular clinical assessments, PSA measurements, post-procedure MRI scans, and biopsies at 36 months or if positive findings were detected earlier. Statistical analyses were conducted to assess trends in PSA levels and cavity dimensions over time. Results: forty patients were initially included, with 15 lost to follow-up. At 36 months, a mean PSA reduction of 60% was observed, and 80% of MRI scans showed no signs of in-field clinically significant residual/recurrent cancer. Biopsies at 36 months revealed no malignant findings in 20 patients. No deterioration in sexual function or urinary symptoms was recorded. Conclusions: FLA appears to be safe, feasible and effective in the index lesion treatment of low-intermediate risk prostate cancer, with a high rate of tumor eradication and preservation of quality of life.

Precise individual tree or sample-based inventories derived from 3D point cloud data of mobile laser scanning can improve our comprehensive understanding of the structure, function, resilience, biodiversity, and ecosystem services of urban forests. This study assessed the performance of a hand-held laser scanning system for the extraction of tree position, diameter at breast height (DBH) and tree height (H) in an urban area. A total of 2083 trees of 13 species from 34 plots were analyzed. The results showed that the registration of tree positions using ground control points (GCPs) demonstrated high accuracy, with errors consistently below 0.4 m, except for a few instances. The extraction accuracy of DBH for all trees and individual species remained consistently high, with a total root mean square error (RMSE) of 2.06 cm (6.89%) and a bias of 0.62 cm (2.07%). Notably, broad-leaved trees outperformed coniferous trees, with RMSE and bias values of 1.86 cm (6%) and 0.76 cm (2.46%) compared to 2.54 cm (9.46%) and 0.23 cm (0.84%). Tree height extraction accuracy varied significantly among different species, with R2 values ranging from 0.65 to 0.92. Generally, both DBH and height were underestimated. Linear mixed effects models (LME) were applied to evaluate factors affecting the performance of HLS with the plot as a random factor. LME analysis revealed that plant type and terrain significantly influenced the accuracy of DBH and H derived from HLS data. Other fixed factors of plot area, tree density and trajectory length didn’t have significance. With a large sample size, we concluded that the HLS demonstrated sufficient accuracy in extracting individual tree parameters in urban forests.

Background: Low-level (LLLT) and high-intensity laser therapy (HILT) can be beneficial additions to knee osteoarthritis (KOA) rehabilitation exercises; however, it is still being determined which modality is more effective. Aim: To compare the effects of LLLT and HILT as adjuncts to rehabilitation exercise (LL+EX and HL+EX) on clinical outcomes in KOA. Methods: Thirty-four adults with mild to moderate KOA were randomly allocated to either LL+EX (n = 17) or HL+EX (n = 17) groups. All participants underwent their designated laser treatment combined with rehabilitation exercises weekly for twelve consecutive weeks. The Knee Injury and Osteoarthritis Outcome Score (KOOS), Numerical Pain Rating Scale (NPRS), active knee flexion, and Timed Up-and-Go test (TUG) were assessed at baseline and immediately post-intervention. Results: Post-intervention, both groups significantly improved their KOOS, NPRS, active knee flexion, and TUG scores compared to baseline (p &lt; 0.01). The mean difference of change in KOOS, NPRS, and active knee flexion scores for the HL+EX group surpassed the minimal clinically important difference threshold. In contrast, the LL+EX group only demonstrated clinical significance in NPRS scores. Conclusions: Incorporating HILT as an adjunct to usual KOA rehabilitation led to significantly higher improvements in pain, physical function, and knee-related disability compared to LLLT.

The energy transfer process of laser selective melting is very complex. To study the effect of la-ser selective melting on the microstructure and properties of 18Ni-300 martensitic steel, ABAQUS was used to simulate the temperature of laser cladding 18Ni-300 martensitic steel at different time points and different laser power. The results show that the cross-section shape of the molten pool changes from round to oval With the increase of laser power, the higher the peak value of temperature time curve, the greater the temperature gradient; and the laser clad-ding experiment of 18Ni-300 martensitic steel was carried out, and the microstructure and me-chanical properties of the samples under different laser power were analyzed. The results show that with the increase of laser power, the grain size of the cladding layer becomes smaller and the microstructure becomes more compact; the hardness of the side surface of the sample is higher than that of the upper surface, and the tensile strength and elongation show a trend of first increasing and then decreasing.

Ground-based high-power lasers enable to, in principle, deorbit any kind of space debris object from the low Earth orbit (LEO) by remotely inducing laser-ablative momentum. However, the assessment of efficiency and operational safety depends on many factors like atmospheric constraints or the risk of debris disintegration during irradiation. We analyze laser momentum for a great variety of target geometries and sizes, and – for the first time in a large-scale simulation – include thermal constraints for laser irradiation configuration. Using a coherently coupled 100 kJ laser system at 1030 nm wavelength, 5 ns pulse duration in an optimized pointing elevation angle range, the pulse frequency should amount to less than 10 Hz to prevent fragment meltdown. For mechanically intact payloads or rocket bodies, repetition rates should be even lower. Small debris fragments sized between 10 and 40 cm can be de-orbited by around 100 to 400 station passes with head-on irradiation while objects exceeding 2 m typically require far more than 1000 irradiations for deorbit. Hence, laser-based debris removal cannot be considered a prime space sustainability measure tackling the top-risk large debris, yet it can provide for remediation of a multitude of small-sized debris using small networks of globally distributed laser sites.

An important surgical goal is to provide a first intention wound healing without trauma produced by sutures and for this aim in the past several methods have been tested. The aim of this preliminary ex vivo study is to demonstrate the capacity of a 1070 nm pulsed fiber laser to treat the dental fractures by dentine melting with the apposition of hydroxyapatite nanoparticles as filler. Only the specimens of the group b showed a real process of welding of the two parts, while specimens of groups a and c did not reach a complete welding process. Out of thirty freshly-extracted human third molars, decay-free, twenty-four cylinders of 5 mm thickness were obtained to perform the test. The device used was a 1070 nm Yb-doped pulsed fiber laser: this source has a maximum average output power of 20 W and a fixed pulse duration of 100 ns, while the repetition rate ranges from 20 kHz to 100 kHz. The samples were divided in three groups (a, b, c) of eight teeth and each specimen, with the two portions strictly placed side by side, was put inside the box and irradiated three times, the first and the second at 30 kW and the last at 10 kW power. The frequency was maintained at 20 kHz for all the tests as well as the speed of the beam at 10 mm/sec. The samples of the group a were irradiated without apposition, in the group b nanoparticles (<200 nm) of hydroxyapatite were put in the gap between the two portions while in the group c, a powder of hydroxyapatite was employed. Only the specimens of the group b showed a real process of welding of the two parts, while specimens of groups a and c did not reach a complete welding process.

Process parameters influencing mechanical properties have always been a critical area of research for quite some time. We investigated the effect of laser power and laser scan velocity on the impact strength and maximum stress of 3D-printed metallic specimens of steel 1.2709 and 1.4542. Laser power significantly affected the impact strength and maximum stress of both the steels. With the increase in laser power, the impact strength increased for 1.2709 steel. However, there was a little increase in the impact strength with increasing laser power in the case of 1.4542 steel. Laser power had a decreasing impact on the maximum stress for 1.2709 steel. For 1.4542, maximum stress increased with increasing laser power, but then gradually declined. We observed that using laser power beyond 350W led to printing defect in the specimens, as maximum stress for some specimens reached close to zero in the case of 1.4542 steel. Laser scan velocity had a strong declining effect on the impact strength of 1.2709 steel.

We report a diode pumped solid state (DPSS) laser used for intracavity pump-enhanced difference frequency generation (DFG) to create a 3.5 micron laser. Using a 50 mm-long periodically poled lithium niobate (PPLN) crystal inside the cavity of an Nd:YVO4 solid state laser at 1064 nm with 4.5 W pump power at 808 nm, and a 310 mW C-band signal at 1529 nm, up to 31 mW of mid-infrared output power at 3499 nm is obtained. The cavity requires no active stabilization and/or locking, and the entire cavity is &lt;8 cm in length. The obtained output power corresponds to a black box efficiency of 2.20 %W-1, which is the highest value reported to date for continuous wave DFG based on a bulk nonlinear optical crystal with no active stabilization. Potential future applications in free space optical communication are discussed as well.

Background:This study evaluated the effect of low-level laser therapy on postoperative pain and wound healing in children undergoing primary molar extractions.Methods:40children,6-10years of age, systemically healthy, and had atraumatic extraction indications of bilateral primary molar teeth were included in the study. First session randomly selected tooth was extracted under local anesthesia. In the control group, only the clot formation on the socket was observed and photographed. Other group extraction's performed 2weeks later. The LLLT group treated with980nm wavelength Doctor Smile Wiser diode laser and photographed. Non-epithelialized surface measurements performed with the ImageJ program. Pain assessment was performed with Wong-Baker Pain Scale. Statistical analyzes were performed with SPSS software.Results: There was no statistically significant difference in Wong-Baker values(p&gt;0.05). The laser group had more '0' values on days 1 and7; same values as the control group were recorded on other days. In soft tissue healing 3rd day evaluations, non-epithelialized surface of laser socket was found to be smaller than control group, and measurement results were found to be statistically significant(p&lt;0.05). The other days' measurement results were not statistically significant(p&gt;0.05).Conclusions:Although LLLT not found to be very effective in reducing postoperative discomfort after extraction of primary molars, it provides better wound healing in extraction sockets.

Magnetic and morphological properties of equiatomic B2-ordered FeRh thin films irradiated with single high-intensity ultrashort laser pulses are investigated. The goal is to elucidate the effect of femtosecond laser ablation on the magnetic properties of FeRh. We employed Scanning Magneto-Optical Kerr Effect (S-MOKE) microscopy to examine the magnetic phase after laser processing, providing high spatial resolution and sensitivity. Our results revealed the appearance of a magneto-optical signal from the bottom of ablation craters, suggesting a transition from antiferromagnetic to ferromagnetic behavior. Fluence-resolved measurements clearly demonstrate that the ablation threshold coincides with the threshold of the antiferromagnet-to-ferromagnet phase transition. The existence of such magnetic phase transition was independently confirmed by temperature-dependent S-MOKE measurements using a CW laser as a localized heat source. Whereas the initial FeRh film displayed a reversible antiferromagnet-ferromagnet phase transition, the laser-ablated structures exhibited irreversible changes in their magnetic properties. This comprehensive analysis revealed the strong correlation between the femtosecond laser ablation process and the magnetic phase transformation in FeRh thin films.

In recent years, laser engraving has received widespread attention as a convenient, efficient, and programmable method, which has enabled the obtaining of high-quality porous graphene from various precursors. Laser engraving is often used to fabricate the dielectric layer with micro-structure for capacitive pressure sensors, however, the usual choice of electrodes remains poorly flexible metal electrodes, which greatly limits the overall flexibility of the sensors. In this work, we propose a flexible capacitive pressure sensor made entirely of thermoplastic polyurethane (TPU) and laser-induced graphene (LIG) derived from wood. The capacitive pressure sensor consisted of a flexible LIG/TPU electrode (LTE), a LIG/TPU electrode with micro hole array, and dielectric layer of TPU with micro-cone array molded from laser-engraved hole array on wood, which provided high sensitivity (0.11 kPa-1), ultra-wide pressure detection range (100Pa to 1.4MPa), fast response (~300 ms) and good stability (&gt;4000 cycles, at 0-35 kPa). We believe that our research makes a significant contribution to the literature because the easily available materials derived from wood and overall consistent flexibility meet the requirements of flexible electronic devices.

Inscription of embedded photoluminescent microbits inside a bulk natural diamond, LiF and CaF2 crystals was performed in sub-filamentation (geometrical focusing) regime by 525nm 0.2ps laser pulses focused by 0.65NA micro-objective as a function of pulse energy, exposure and inter-layer separation. The resulting microbits were visualized by 3Dscanning confocal Raman/photoluminescence microscopy as conglomerates of photo-induced quasi-molecular color centers and tested regarding their annealing. Minimal lateral and longitudinal microbit separations, enabling their robust read-out, were measured in LiF as 1.5 and 13 microns, respectively, to be improved regarding information storage capacity by more elaborate focusing systems. These findings pave a way to novel optical storage platforms utilizing ultrashort-pulse laser inscription of photoluminescent microbits as carriers of archival memory.

A 3D graphene foam made of interconnected multilayer graphene flakes was produced on optical fibres (OF) by laser-induced transformation of a polyimide (PI) film coated on the OF cladding. This material, known as la-ser-induced graphene (LIG), was explored in the electrochemical detection and quantification of dopamine (DA) at physiologically relevant concentrations in the presence of the most relevant interfering molecules in biological fluids, ascorbic acid (AA) and uric acid (UA). The measured limit of detection is 100 nM, the linear range is 0.1 to 5 μM and a maximum sensitivity of 5.0 µA µM−1 cm−2 was obtained for LIG decorated with Pt nanoparticles (NPs). Moreover, immunity to AA and UA interference and to fouling was attained by decorating the LIG elec-trode with Pt NPs and coating with Nafion. These figures of merit underlines the potential of these sensors for the quantification of physiologically relevant concentrations of DA in biological fluids, paving the way for the development of hybrid electrochemical/optical sensing actuating platforms in a lab-on-fibre configuration, with relevant applications in biomedical engineering. The advantages of this hybrid arrangement include the possi-bility of in-situ counterproofing, extended measuring ranges, photoelectrochemical detection and the probing of inaccessible places. This elegant approach can also provide a simple and cost-effective way to fabricate biomed-ical devices with extended functionality, such as medical optical probes with added electrochemical capabilities, optogenetics combined with local electrochemical detection, among others.

In recent years, tremendous progress has been made in the development of rare-earth ion doped tellurite glass laser sources, ranging from watt and multiwatt level fiber lasers to nanowatt level microsphere lasers. Significant success has been achieved in extending the spectral range of tellurite fiber lasers generating at wavelengths beyond 2 μm as well as in theoretical understanding. This review is aimed at discussing the state of the art of neodymium-, erbium-, thulium-, and holmium-doped tellurite glass fiber and microsphere lasers.

As fatigue properties of as-built components of additively manufactured (AM) metals are considerably weaker than those of wrought metals because of rougher surface, post-processing is necessary to improve fatigue properties. To demonstrate improvement of fatigue properties of AM metals by post-processing, powder bed fusion (PBF) using laser sintering (LS) AlSi10Mg, i.e., PBF-LS/AlSi10Mg was treated by “submerged laser peening (SLP)” using a fiber laser and/or a Nd:YAG laser, then evaluated by plane bending fatigue tests. At SLP, “laser ablation (LA)” is generated by a pulsed laser, and a bubble is generated after LA, which behaves like a cavitation bubble that is named as “laser cavitation (LC)”. In the present paper, LA-dominated SLP is called as “laser treatment (LT)”, while LC-collapse-dominated SLP is called as “laser cavitation peening (LCP)”, as impact at LC collapse is used for peening. It was revealed that SLP using the fiber laser was LT rather than LCP. It was demonstrated that the fatigue strength at N = 10^7 was 85 MPa for LCP, and 103 MPa for combined process of blasting (B) + LT + LCP, whereas the fatigue strength of as-built specimen was 54 MPa.

Artificial intelligence (AI)-based conversational models, such as ChatGPT, Microsoft Bing, and Google Bard, emerged as valuable sources of health information for the lay individuals. However, the accuracy of information provided by these AI models remains a significant concern. This pilot study aimed to test a new tool referred to as “CLEAR”, designed to assess the quality of health information delivered by AI-based models. Tool development involved a literature review on health information quality, followed by initial establishment of the CLEAR tool comprising five items that aimed to assess the following: completeness of content in response to the prompt, lack of false information, evidence support, appropriateness, and relevance of the generated content. Each item was scored on a 5-point Likert scale from excellent to poor. Content validity was checked by expert review of the initial items. Pilot testing involved 32 healthcare professionals using the CLEAR tool to assess content on eight different health topics deliberately designed with varying qualities. The internal consistency was checked using the Cronbach α. Feedback through the pilot test resulted in language modifications to improve the clarity of the items. The final CLEAR tool was used to assess health information quality generated through four different AI-based models in five different, yet common health topics. The AI models were ChatGPT 3.5, ChatGPT 4, Bing, and Bard, and the content generated was scored by two independent raters with Cohen κ to assess the inter-rater agreement. The final five CLEAR items were: (1) Is the content sufficient? (2) Is the content accurate? (3) Is the content evidence-based? (4) Is the content clear, concise, and easy to understand? and (5) Is the content free from irrelevant information? Pilot testing using the eight different health topics revealed an acceptable internal consistency with a Cronbach α range of 0.669–0.981. The use of the final CLEAR tool yielded the following average scores: Bing (mean=24.4±0.42), ChatGPT-4 (mean=23.6±0.96), Bard (mean=21.2±1.79), and ChatGPT-3.5 (mean=20.6±5.20). The inter-rater agreement revealed the following Cohen κ values: for ChatGPT-3.5 (κ=0.875, P<.001), ChatGPT-4 (κ=0.780, P<.001), Bing (κ=0.348, P=.037), and Bard (κ=.749, P<.001). The CLEAR tool is a brief yet helpful tool that can aid to standardize testing of the quality of health information generated by the AI-based conversational models. Future studies are recommended to validate the utility of the CLEAR tool to assess the quality of the AI-generated health-related content using a larger sample across various complex health topics.

Background: ChatGPT is becoming a new reality. Where do we go from here? Objective: to show how we can distinguish ChatGPT-generated publications from counterparts produced by scientist. Methods:By means of a new algorithm, called xFakeBibs, we show the significant difference between ChatGPT-generated fake publications and real publications. Specifically, we triggered ChatGPT to generate 100 publications that were related to Alzheimer’s disease and comorbidity. Using TF-IDF, using the real publications, we constructed a training network of bigrams comprised of 100 publications. Using 10-folds of 100 publications each, we also 10 calibrating networks to derive lower/upper bounds for classifying articles as real or fake. The final step was to test xFakeBibs against each of the ChatGPT-generated articles and predict its class. The algorithm successfully assigned the POSITIVE label for real ones and NEGATIVE for fake ones. Results: When comparing the bigrams of the training set against all the other 10 calibrating folds, we found that the similarities fluctuated between (19%-21%). On the other hand, the mere bigram similarity from the ChatGPT was only (8%). Additionally, when testing how the various bigrams generated from the calibrating 10-folds against ChatGPT we found that all 10 calibrating folds contributed (51%-70%) of new bigrams, while ChatGPT contributed only 23%, which is less than 50% of any of the other 10 calibrating folds. The final classification results using the xFakeBibs set a lower/upper bound of (21.96-24.93) number of new edges to the training mode without contributing new nodes. Using this calibration range, the algorithm predicted 98 of the 100 publications as fake, while 2 articles failed the test and were classified as real publications. Conclusions: This work provided clear evidence of how to distinguish, in bulk ChatGPT-generated fake publications from real publications. Also, we also introduced an algorithmic approach that detected fake articles with a high degree of accuracy. However, it remains challenging to detect all fake records. ChatGPT may seem to be a useful tool, but it certainly presents a threat to our authentic knowledge and real science. This work is indeed a step in the right direction to counter fake science and misinformation.

Low-cost monitors make it possible now for the first time to collect long-term (months to years) measurements of potential indoor exposure to fine particles. Indoor exposure is due to two sources: particles infiltrating from outdoors and those generated by indoor activities. Calculating the relative contribution of each source requires identifying an infiltration factor. We develop a method of identifying periods when the infiltration factor is not constant, and searching for periods when it is relatively constant. From an initial regression of indoor on outdoor particle concentrations, a Forbidden Zone can be defined with an upper boundary below which no observations should appear. If many observations appear in the Forbidden Zone, they falsify the assumption of a single constant infiltration factor. This is a useful quality assurance feature, since investigators may then search for subsets of the data in which few observations appear in the Forbidden Zone. The usefulness of this approach is illustrated using examples drawn from the PurpleAir network of optical particle monitors. An improved algorithm is applied with reduced bias, improved precision, and a lower limit of detection than either of the two proprietary algorithms offered by the manufacturer of the sensors used in PurpleAir monitors.

Transcription factors (TFs) and microRNAs (miRNAs) are co-actors in genome-scale decoding and regulatory networks, often targeting common genes. In this paper, we describe the algebraic geometry of both TFs and miRNAs thanks to group theory. In TFs, the generator of the group is a DNA-binding domain while, in miRNAs, the generator is the seed of the sequence. For such a generated (infinite) group $\pi$, we compute the $SL(2,\mathbb{C})$ character variety, where $SL(2,\mathbb{C})$ is simultaneously a \lq space-time' (a Lorentz group) and a \lq quantum' (a spin) group. A noteworthy result of our approach is to recognize that optimal regulation occurs when $\pi$ looks like a free group $F_r$ ($r =1$ to $3$) in the cardinality sequence of its subgroups, a result obtained in our previous papers. A non free group structure features a potential disease. A second noteworthy result is about the structure of the Groebner basis $\mathcal{G}$ of the variety. A surface with simple singularities (like the well known Cayley cubic) within $\mathcal{G}$ is a signature of a potential disease even when $G$ looks like a free group $F_r$ in its structure of subgroups. Our methods apply to groups with a generating sequence made of two to four distinct DNA/RNA bases in $\{A,T/U,G,C\}$. Several human TFs and miRNAs are investigated in detail thanks to our approach.

We introduce optically clear and resilient free-form micro-optical of pure (non-photosensitized) organic-inorganic SZ2080 material made by femtosecond 3D laser lithography (3DLL). This is advantageous for rapid printing of 3D micro-/nanooptics, including their integration directly onto optical fibers. A systematic study on the fabrication peculiarities and quality of resultant structures is performed. Comparison of microlenses’ resiliency to CW and femtosecond pulsed exposure is determined. Experimental results prove that pure SZ2080 is ∼3 fold more resistant to high irradiance as compared with a standard photo-sensitized material and can sustain up to 1.91 GW/cm² intensity. 3DLL is a promising manufacturing approach for high-intensity micro-optics for emerging fields in astro-photonics and atto-second pulse generation. Additionally, pyrolysis is employed to shrink structures up to 40% by removing organic SZ2080 constituents. This opens a promising route towards downscaling photonic lattices and creation of mechanically robust glass-ceramic structures.

This Dataset reports the clinical information and measurements of 231 patients who underwent multifrequency low-level laser-assisted mastopexy. The Dataset was collected between February 2021 and November 2023. These data were used to assess the effect of this procedure on breast ptosis degree and the nipple to sternal notch distance to know the evolution of breast ptosis. This article presents demographic, personal and familial history, anthropometric measurements, pto-sis degree according to the Regnault system, Nipple-to-Sternal Notch distance (SNND), and complications according to the Clavien-Dindo System. The collected data were in English, and the responses were anonymised to ensure the Colombian legal framework. The data were stored in a .csv file.

Neutron beams are an essential tool to investigate material structure and perform non-destructive analysis, as they give unique access to element composition, thus ideally complementing density analysis allowed by standard X-rays investigation. Laser-driven neutron sources, though compact and cost-effective, currently have lower average flux than conventional neutron sources, due to the limited repetition rate of the lasers used so far. However, advancements in laser technology allow nowadays to address this challenge. Here we report results obtained at the Advanced Laser Light Source (ALLS) characterizing stable production of broadband (0.1-2 MeV) neutrons produced at a high repetition rate (0.5 Hz). The interaction of laser pulses of 22 fs duration and 3.2 J on-target energy with 2-µm-thick tantalum targets produced protons in the Target Normal Sheath Acceleration (TNSA) regime up to 7.3 MeV. These protons were subsequently converted into neutrons by (p,n) reactions in Lithium fluoride (LiF). Activation measurements and bubble detectors were used to characterize neutron emissions, with a neutron fluence of up to ~ 1.4 × 10⁵ neutrons/shot/sr, and energies mainly between a few hundred of keV and 2 MeV. The total neutron yield was ~ 5 × 10⁵ neutrons/shot. This paves the way for numerous applications, e.g. in homeland security, material science or cultural heritage.

This paper presents the design and experimental results of a long cavity length Nd: YAG laser with large stable zone for water jet guided laser (WJGL) applications. The design is based on the light transmission matrix and resonator stability conditions, aiming to achieve a large stable zone and a short cut-off thermal focal length (CTFL). A folded concave resonator is researched to enhance the cavity length, and the influence of the tun-able cavity arm length on the oscillating beam in the resonator and in the YAG crystal is theoretically studied. Moreover, the effects of the output mirror curvature and the cavity arm length on the range of the stable area and the cut-off thermal focal length are also investigated. Experimental results show that a stable green laser output is obtained after second harmonic generation (SHG), with a pulse width ranging from 43ns to 143ns within the laser operating frequency range of 5-20kHz. At an operation frequency of 10kHz, the output power is 21.33W, and the instability of the output power within 400 minutes is 0.88%. The laser source achieves a maximum power of 25.7W at 20kHz, and the maximum single pulse energy reaches 2.7mJ at 6kHz. Finally, this is used as the laser source to couple with a water jet with a diameter of 100 microns, achieving a lossless water conductivity transmission over 60mm length with a peak power density of 0.742GW/cm2. These results demonstrate the suitability of the designed laser source for WJGL technology research.

Dentinal Hypersensitivity (DH), a prevalent oral health issue affecting approximately one-third of adults. In this six-months retrospective study, a comparison was made to assess the effectiveness of two diode lasers with different wavelengths (980 nm and 1064 nm) in the treatment of tooth affected by DH. In total, 160 patients were divided into two treatment groups: one receiving treatment with a 980 nm diode laser (n=80) and the other with a 1064 nm diode laser (n=80). Pain was assessed using the Visual Analogue Scale (VAS) at baseline, immediately post-treatment, and at 3- and 6-months follow-up. Both groups followed the same treatment protocol, involving the application of a graphite paste to the exposed dentin before laser irradiation. Both lasers operated at an output power of 0.5 W in continuous and non-contact mode, with a 320 µm spot size. A significant reduction in mean VAS scores at all follow-up intervals compared to baseline was noted. 980 nm group had mean VAS scores of 7.9, 2.36, 2.31, and 2.38, while the 1064 nm group had scores of 8.01, 1.01, 1.16, and 1.13 at baseline, immediately post-treatment, and at 3 and 6 months, respectively. At all times of follow-up, the 1064 nm wavelengths showed a statistically significant reduction in mean values of VAS compared to the 980 nm. The findings may inform future research on optimizing laser-based treatments for DH.

Laser-induced functionalisation using excimer laser irradiation has been widely applied to transparent conductive oxide films. However, exploring suitable irradiation conditions is time-consuming and cost-ineffective as there are numerous routine film fabrication and analytical processes. Thus, we herein explored a real-time technique to monitor the laser-induced functionalisation of transparent conductive oxide films. We developed two types of monitoring apparatus, electrical and optical, and applied them to magnetron-sputtered Sn-doped In2O3 films grown on glass substrates and hydrogen-doped In2O3 films on glass or plastic substrates using a picosecond Nd:YAG pulsed laser. Both techniques could monitor the functionalisation from a change in properties of the films on glass substrates by laser irradiation, but electrical measurement was unsuitable for plastic samples because of a laser-induced degradation of the underlying plastic substrate, which harmed proper electrical contact. Instead, we demonstrated that the optical properties in the near-infrared region were suitable for the monitoring and the changes in the optical properties were visually detected in real-time by using a near-infrared camera.

Laser-induced periodic surface structures (LIPSS) have gained significant attention due to their ability to modify the surface morphology of materials at the micro-nanoscale and show great promise for surface functionalization application. In this study, we specifically investigate the formation of LIPSS in silicon substrates and explore their impact on Surface-Enhanced Raman Spectroscopy (SERS) applications. This study reveals a stepwise progression of LIPSS formation in silicon, involving three distinct stages of LIPSS: 1) integrated Low-Spatial-Frequency LIPSS (LSFL) and High-Spatial-Frequency LIPSS (HSFL), 2) principally LSFL and 3) LSFL at the edge of the irradiated spot, elucidating the complex interplay between laser fluence, pulse number, and resulting surface morphology. Furthermore, from an application standpoint, these high-quality multi-scale periodic patterns lead to the next step of texturing the entire silicon surface with homogeneous LIPSS for SERS application. The potential of LIPSS-fabricated silicon substrates for enhancing SERS performance is investigated using thiophenol as a test molecule. The results indicate that the Au-coated combination of LSFL and HSFL substrate showcased the highest enhancement factor (EF) of 1.38 × 10^6. This pronounced enhancement is attributed to the synergistic effects of Localized Surface Plasmon Resonance (LSPR) and Surface Plasmon Polaritons (SPPs), intricately linked to HSFL and LSFL characteristics. These findings contribute to understanding LIPSS formation in silicon and their applications in surface functionalization and SERS, paving the way for sensing platforms.

Abstract: Arranged patterns obtained by ultrafast laser processing on the surface of Ti/Cu/Ti/Si and Ti/Zr/Ti/Si thin film systems are reported. Two differently designed multilayer thin films, Ti/Cu/Ti/Si and Ti/Zr/Ti/Si, were deposited on silicon by the ion sputtering method. The bioactive surfaces on these systems involve the formation of laser-induced periodic surface structures (LIPSS) in each of the laser-written lines of mesh patterns on 5x5 mm areas. The formation of nano- and micro-patterns with an ultra-thin oxide film on the surfaces was used to observe the effects of morphology and proliferation of the MRC-5 cell culture line. To determine whether Ti-based thin films have a toxic effect on living cells, an MTT assay was performed. The relative cytotoxic effect as a percentage of surviving cells showed that there was no difference in cell number between the Ti-based thin films and the control cells. There was also no difference in the viability of the MRC-5 cells, except for the Ti/Cu/Ti/Si system, where there was a slight 10% decrease in cell viability.

This paper reviews state of the art Additive Manufactured (AM) IN718 alloy intended for high temperature applications. AM processes have been around for decades and have gained traction in the past five years due to the huge economic benefit it brings to manufacturers. It is crucial for the scientific community to look into AM IN718 applicability in order to see a step-change in the production. Microstructural studies reveal that the grain structure plays a significant role in determining the fatigue lifespan of the material. Controlling IN718 respective phases such as the ϒ’', δ and Laves phase is seen to be crucial. Literature reviews have shown that the mechanical properties of AM IN718 were very close to its wrought counterpart when treated appropriately. Higher homogenization temperature and longer ageing were recommended to dissolve the damaging phases. Various surface enhancement techniques were examined to find out their compatibility to AM IN718 alloy that is intended for high temperature application. Laser shock peening (LSP) technology stands out due to the ability to impart low cold work which helps in containing the beneficial compressive residual stress it brings in high temperature fatigue environment.

Optical biopsy describes a range of medical procedures in which light is used to investigate disease in the body, often in hard-to-reach regions via optical fibres. Optical biopsies can reveal a multitude of diagnostic information to aid therapeutic diagnosis and treatment with higher specificity and shorter delay than traditional surgical techniques. One specific type of optical biopsy relies on Raman spectroscopy to differentiate tissue types at the molecular level and has been used successfully to stage cancer. However, complex micro-optical systems are usually needed at the distal-end to optimise the signal-to-noise properties of the Raman signal collected. Manufacturing these devices remains a critical challenge, particularly in a way suitable for large scale adoption. In this paper, we describe a novel fibre-fed micro-optic system designed for efficient signal delivery and collection during a Raman spectroscopy based optical biopsy. Crucially, we fabricate the device using a direct-laser-writing technique known as ultrafast laser assisted etching which is scalable and allows components to be aligned passively. The Raman probe has a sub-millimetre diameter and offers confocal signal collection with 71.3 ± 1.5% collection efficiency over a 0.8 numerical aperture. Proof of concept spectral measurements were performed on mouse intestinal tissue and compared with results obtained using a commercial Raman microscope.

A laser-based hydrogen (H₂) sensor using wavelength modulation spectroscopy (WMS) was developed for contactless measurements of molecular hydrogen. The sensor uses a distributed feedback (DFB) laser to target the H₂ quadrupole absorption line at 2121.8 nm. The H₂ absorption line exhibits weak collisional broadening and strong collisional narrowing effects. Both effects were investigated by comparing measurements of the absorption linewidth with detailed models using different line profiles that include collisional narrowing effects. The collisional broadening and narrowing parameters were determined for pure hydrogen as well as for hydrogen in nitrogen and air. Performance of the sensor was evaluated and the sensor applicability for H₂ measurements in a range of 0- 10 %v of H₂ was demonstrated. A precision of 0.02 %v was achieved with 1 meter of absorption pathlength (0.02 %v∙m) and 1 s of integration time. For the optimum averaging time of 20 s a precision of 0.005 %v∙m was achieved. A good linear relationship between H₂ concentration and the sensor response was observed. A simple and robust transmitter-receiver configuration of the sensor allows in-situ installations in harsh industrial environments.

K417G Ni-based superalloy is widely used in aeroengine turbine blade for its excellent properties. However, the aeroengine rotor blade zigzag crown appears early failure frequently, which is because of the wear problems occurring in the working process. Laser forming repairing (LFR) is a promising technique to repair these damaged blades. Unfortunately, the laser formed Ni-based superalloys with high content of (Al + Ti) have a high cracking sensitivity. In this paper, the crack characterization of the LFRed K417G, the microstructure, microhardness and tribological properties of the coating before and after laser remelting are presented. The results show that the microstructure of as-deposited K417G consists of γ phase, γ′ precipitated phase, γ + γ′ eutectic and carbide. Cracking mechanisms including solidification cracking, liquation cracking and ductility dip cracking are proposed based on the composition of K417G and processing characteristics to explain the cracking behavior of the K417G superalloy during LFR. After laser remelting, the microstructure of the coating has been refined, and the microhardness and tribological properties has been improved. Laser remelting can decrease the size of the cracks in the LFRed K417G but not the number. Therefore, laser remelting can be applied as an effective method for strengthening coating and as an auxiliary method for controlling cracking.

Revealing the time structure of physical or biological objects is usually performed thanks to the tools of signal processing like the fast Fourier transform, Ramanujan sum signal processing and many other techniques. For space-time topological objects in physics and biology, we propose a type of algebraic processing based on schemes in which the discrimination of singularities within objects is based on the space-time-spin group SL(2,C). Such topological objects possess an homotopy structure encoded in their fundamental group and the related SL(2,C) multivariate polynomial character variety contains a plethora of singularities somehow analogous to the frequency spectrum in time structures. Our approach is applied to an Akbulut cork in exotic R4, to an hyperbolic model of topological quantum computing based on algebraic surfaces and to microRNAs in genetics. Such diverse topics reveal the manifold of possibilities of using the concept of a scheme spectrum.

There is much discussion regarding the Sustainable Development Goals’ (SDGs) capacity to promote inclusive development. While some argue that they represent an opportunity for goal-led alignment of stakeholders and evidence-based decision-making, other voices express concerns as they perceive them as a techno-managerial framework that measures development according to quantitatively defined parameters and does not allow for local variation. We argue that the extent to which the positive or negative aspects of the SDGs prevail depends on the monitoring system’s ability to account for multiple and intersecting inequalities. The need for sub-nationally (urban) representative indicators poses an additional methodological challenge – especially in cities with intra-urban inequalities related to socio-spatial variations across neighbourhoods. This paper investigates the extent to which the SDG indicators’ representativeness could be affected by inequalities. It does so by proposing a conceptual framing for understanding the relation between inequalities and SDG monitoring, which is then applied to analyse the current methodological proposals for the indicator framework of the “urban SDG”, Goal 11. The outcome is a call for 1) a more explicit attention to intra-urban inequalities, 2) the development of a methodological approach to “recalibrate” the city-level indicators to account for the degree of intra-urban inequalities, and 3) an alignment between methodologies and data practices applied for monitoring SDG 11 and the extent of the underlying inequalities within the city. This would enable an informed decision regarding the trade-off in indicator representativeness between conventional data sources, such as censuses and household surveys, and emerging methods, such as participatory geospatial methods and citizen-generated data practices.

Silicon carbide single crystal (SiC) has been widely used in the field of power devices, while it is difficult to fabricate ultra-flat surface by traditional manufacturing technologies due to its difficult-to-machine property. This paper investigates the interaction process during femtosecond laser ablation of crystalline silicon carbide based on the two-temperature model simulation and experimental study. The findings reveal that parameters such as laser pulse energy, scanning interval, and defocus amount exert significant influence on ablation depth, roughness, and surface morphology. The femtosecond laser proves effective in removing surface defects from cut SiC substrates, albeit resulting in increased surface roughness. However, subsequent polishing treatment of the laser-ablated silicon carbide surface can mitigate this roughness, underscoring the feasibility of laser surface ablation for silicon carbide single crystals.

We demonstrate a proof-of-principle of simple all-solid-state post-compression setup for low energy, high repetition rate laser pulses, where spectral broadening was performed using a combination of highly nonlinear bulk materials in a simple single pass geometry. 75 fs, 210 nJ pulses from an amplified 76 MHz, 15.7 W Yb:KGW oscillator after sequential spectral broadening in ZnS and YAG samples of 2 mm and 15 mm thickness, respectively, were compressed to 37 fs by means of Gires–Tournois interferometric mirrors. The post-compressed pulses with an average power of 11.47 W demonstrated reasonable spatial-spectral homogeneity of the beam with the spectral overlap parameter V>83% and good beam quality with Mx2=1.28 and My2=1.14.

Spontaneous parametric downconversion At the heart of all quantum optics experiments is called as Spontaneous parametric downconversion. This is a downconversion process when the output frequency is smaller than the input frequency. The whole process is Spontaneous. Experimentally we have to downconvert the photons and convert them into pairs of a photon. We use the Beta-barium borate(BBO) crystals to downconvert the coming violet-blue laser. We find the maximum number of counts on detectors and their coincidence. When the BBO crystals is well aligned, we find no difference in detecting vertically or horizontally polarized photons because they are orthogonal to each other. Proof of existence of photons We want to investigate the properties and verification of quantization of light. Experimently we want to establish the existence of single photon which shows the grainy-ness of individual photon quantum mechanically and shows wave like behaviour classically. We get the coincidences counts on detectors with addition of detector B’ by using PBS in the path of signal beam. Experimentally we prove the Quantum as well as classical nature of light by the measurement of second-order degree coherence in light g²(0). For classically the g²(0)≥1 and quantum mechanically g²(0)=0.When we add the delay time interval of 1ns after reflected and transmitted photons from PBS signal beam. The delay generator did not create a significant difference in the coincidence counts detection in the value of g²(τ ). Single photon interference and quantum eraser we want to observe the interference by making the single photons pass through the interferometer, and we will see the interference of the single photons. If the light passes through the interferometer, the visibility of the interference pattern to which extent these fringes are observed is dependent on the extent to which the ’which-way’ or ’which-path’ information is available to the experimenter. If the observer knows the information about the ’which-way’ of the light path, then we cannot observe the inference pattern. Because we only can make an interference pattern if we erase the which-way information of the light path. If you erase the information about the’ which-way,’ we can observe a very high interference pattern. We can erase the information about the light path’s ’which-way’ or ’which-path’ by using a polarizer and orienting at 45^o. In this way, we can observe a very high pattern. If we introduce the angle of the polarizer at 0^o or 90^o, we see very low interference.

Laser-induced graphene (LIG) has gained considerable attention recently due to its unique properties and potential applications. In this study, we investigate using LIG in polyimide (PI) as a material for antenna applications. The LIG-PI composite material was prepared by a facile picosecond laser (1064 nm) irradiation process, which resulted in a conductive graphene network within the PI matrix. Furthermore, LIG formation was confirmed by Raman spectroscopy and sheet resistance measurements. Finally, a patch antenna from LIG for 2.45 GHz microwaves was simulated, produced and tested. These findings suggest that LIG-PI composites have great potential for use in high-frequency electronic devices and can provide a new avenue for the development of flexible and wearable electronics.

Materials known as Nd:YAG are crystalline materials of the cubic system made from neodymium-doped yttrium aluminum garnet, which among others, have excellent optical properties. Nd:YAG four-level laser devices are highly used in both the health and industrial sectors. In this study, a simple and inexpensive alternative to manufacturing Nd:YAG materials through solid state reactions following powder processing routes was proposed. For this, an intense mixture of the precursor materials (Al2O3 and Y2O3) was carried out, followed by the addition of neodymium atoms to improve the optical properties of the resulting material. High energy mechanical mixing of the precursor powders resulted in submicron particles, with good size distributions of the powders. The advance of YAG formation was monitored by intermediate phase formation during heat treatment through interrupted tests at different temperatures and analysis by X-ray diffraction. From this analysis, it was found that reaction for the formation of the desired YAG is completed at 1500°C. Fourier-transform infrared spectroscopy analyses determined the presence of functional groups corresponding to the YAG. Finally, the study by optical emission spectroscopy showed wavelengths in agreement with the electronic structure of the elements of the synthesized Nd:YAG.

We study the synchronous dynamics of three diffusively coupled erbium-doped fiber lasers (EDLFs) in the unidirectional ring configuration without external pump modulation. The dynamical behavior of the system is analyzed using time series, Fourier spectra, Poincaré sections, bifurcation diagrams, and Lyapunov exponents for different values of the coupling strength. For weak coupling, we observe a well-known route to chaos from a stable equilibrium through a Hopf bifurcation and a series of torus bifurcations as the coupling strength is increased. An interesting result is found for large values of the coupling strength, where the phase locking is close to zero. This allows a significant increase in the peak energy of the EDFLs pulses, i.e., above the coupling strength the lasers switch to a Q-switching mode with large-amplitude short pulses. This result allows us to propose a new method for increasing the laser pulse energy based on the control of the bistability by the rotating wave in the array of three unidirectionally ring-coupled EDFLs as a function of the coupling strength. In our system, we were able to increase the peak laser power by almost 20 times more than a continuous single EDFL.

The wide application of graphene in the industry requires the direct growth of graphene films on silicon substrates. In this study, we find a possible technique to meet the requirement above. Multilayer graphene thin films (MLG) are grown without a catalyst on Si/SiO2 by pulsed laser deposition (PLD). It was found that the minimum number of laser pulses that are required to produce fully covered (uninterrupted) samples is 500. This number of laser pulses resulted in samples that contain ~5 layers of graphene. The number of layers was not affected by the laser fluence and the sample cooling rate after the deposition. However, the increase of the laser flu-ence from 0.9 J/cm2 to 1.5 J/cm2, results in 2.5 fold reduction of the MLG resistance. The present study reveals that the PLD method is suitable to produce nanocrystalline multilayer graphene with electrical conductivity of the same magnitude as commercial CVD graphene samples.

To increase the network computer and mobile telephone capacity one needs a laser to carry information instead of electrons. Since the laser is very fast compared to electrons, one expects information to be transmitted very fast through the network (internet). This requires searching for chips that act as capacitors, inductors, or evens as resistors this work shows that the laser traveling beam diminished as the frequency reciprocal thus acts as a capacitor or diminished as frequency thus acts as an inductor and sometimes diminished with the concentration of carriers thus act as a resistor for magnetic materials with strength that cancels the friction force when the laser frequency is equal nearly to the atoms natural frequency the material act as an inductor. Then frictional force is dominant with high mobility dielectric, the material acts as a capacitor. However, it acts as a conductor for negligible friction and natural frequency.

In this work, we demonstrate that cutting diamond crystals with a laser (532 nm wavelength, 0.5 mJ energy, 200 ns pulse duration at 15 kHz) produces a ≲20nm thick surface layer with magnetic order at room temperature. We have measured the magnetic moment with a SQUID magnetometer of six natural and six CVD diamond crystals of different size, nitrogen content and surface orientations. A robust ferromagnetic response at 300 K is observed only for crystals that were cut with the laser along the (100) surface orientation. The magnetic signals are much weaker for the (110) and negligible for the (111) orientations. We attribute the magnetic order to the disordered graphite layer produced by the laser at the diamond surface. The ferromagnetic signal vanished after chemical etching or after moderate temperature annealing. The obtained results indicate that laser treatment of diamond may pave the way to create ferromagnetic spots at its surface.

Inflammation of the periodontal tissue (periodontitis) is the highest problem of oral health in Indonesia after caries. Photoacoustic imaging (PAI) is a new imaging technique that can be simply constructed using a diode laser combined with a condenser microphone. This study aims to determine that a simple PAI system was able to image periodontal disease in animal model. Samples of the study were normal periodontal and periodontitis tissue, obtained from Sprague-Dawley rats that were divided into four groups, i.e. the control group, treatment group 1 (7 days periodontitis induction), treatment group 2 (11 days periodontitis induction), and treatment group 3 (14 days periodontitis induction). The PAI system was controlled by Labview and Arduino IDE software from a personal computer. Results of the study reveal that the optimal frequency of laser modulation for periodontal tissue imaging was 19 kHz with duty cycle of 50%. Photoacoustic (PA) intensity was obtained from higher to lower of -68,71 dB (treatment group 3), -70,69 dB (treatment group 2), -71,69 dB (treatment group 1), and -73,07 dB (control group) respectively. The photoacoustic images were analyzed to define the contrast between sample and media. The PA intensity of the samples were higher than media. Therefore, this study demonstrate the feasibility of simple PAI system to differentiate normal periodontal tissue and periodontitis.

Silver particles are prepared by dewetting Ag films coated on glass using a fiber laser. The size of the particles is controlled in the range of 92 nm ~ 1.2 μm by adjusting the thickness of the Ag film. The structural properties and surface roughness of the particles are evaluated by means of scanning electron microscopy. In addition, the antifungal activity of the Ag particles is examined using spore suspensions of Colletotrichum gloeosporioides. It is shown that the particles with a size of 1.2 μm achieve 100% inhibition of the conidia growth of the Colletotrichum gloeosporioides after a contact time of just 5 min. Furthermore, the smaller particles also achieve a good antibacterial activity given a longer contact time. Similar results are observed in spore germination and pathogenicity tests performed on mango fruit and leaves. Overall, the results confirm that the Ag particles have an excellent antifungal effect on Colletotrichum gloeosporioides.

Birefringence of 3 × 10^-3 is demonstrated inside cross-sectional regions of 100 µm, inscribed by axially stretched Bessel-beam-like fs-laser pulses along the c-axis inside sapphire. A high birefringence and retardance of λ/4 at mid-visible spectral range (green) can be achieved utilizing stretched beams with an axial extension of 30-40 µm. Conditions of laser writing chosen ensure that there are no formations of self-organised nano-gratings. This method can be adopted for the creation of polarisation optical elements and fabrication of spatially varying birefringent patterns for optical vortex generation.

World health is increasingly threatened by the growing number of spice-related food hazards. Further development of reliable methods for rapid, non-targeted identification of counterfeit ingredients within the supply chain is needed. ENEA has developed a portable, user-friendly photoacoustic laser system for food fraud detection, based on a quantum cascade laser and multivariate calibration. Following a study on the authenticity of saffron, the instrument was challenged with a more elusive adulterant, olive leaves in oregano. The results show that the reported method of laser sensing and chemometric analysis was able to detect adulterants at mass ratios of at least 20% in less than five minutes.

Three-dimensional porous nanostructures made of noble metals represent novel class of nanomaterials promising for nonlinear nanooptics and sensors. Such nanostructures are typically fabricated using either reproducible yet time-consuming and costly multi-step lithography protocols or less reproducible chemical synthesis that involve liquid processing with toxic compounds. Here, we combined scalable nanosecond-laser ablation with advanced engineering of the chemical composition of thin substrate-supported Au films to produce nanobumps containing multiple nanopores inside. Most of the nanopores hidden beneath the nanobump surface can be further uncapped using gentle etching of the nanobumps by an Ar-ion beam to form functional 3D plasmonic nanosponges. The nanopores 10-150~nm in diameter were found to appear via laser-induced explosive evaporation/boiling and coalescence of the randomly arranged nucleation sites formed by nitrogen-rich areas of the Au films. Density of the nanopores can be controlled by the amount of the nitrogen in the Au films regulated in the process of their magnetron sputtering assisted with nitrogen-containing discharge gas.

Amorphous silicon (α-Si) film present an inexpensive and promising material for optoelectronic and nanophotonic applications. Its basic optical and optoelectronic properties are known to be improved via phase transition from amorphous to polycrystalline phase. Infrared femtosecond laser radiation can be considered as a promising nondestructive and facile way to drive uniform in-depth and lateral crystallization of α-Si films that are typically opaque in UV-visible spectral range. However, so far only a few studies reported on utilization of near-IR radiation for laser-induced crystallization of α-Si providing no information regarding optical properties of the resultant polycrystalline Si films. The present work demonstrates efficient and gentle single-pass crystallization of α-Si films induced by their direct irradiation with near-IR femtosecond laser pulses coming at sub-MHz repetition rate. Comprehensive analysis of morphology and composition of laser-annealed films by atomic-force microscopy, optical, micro-Raman and energy-dispersive X-ray spectroscopy, as well as numerical modeling of optical spectra, confirmed efficient crystallization of α-Si and high-quality of the obtained films. Moreover, we highlight localized laser-driven crystallization of α-Si as a promising way for optical information encryption, anti-counterfeiting and fabrication of micro-optical elements.

This study evaluated the effect of low-level laser irradiation induces by diode laser on the speed of orthodontic tooth movement of canines submitted to initial retraction. Twenty-four mandibular canines were retracted by using NiTi spring (force of 150 g/side). Thirteen of those were irradiated with a diode laser 980-nm diode laser (Wiser Laser Doctor Smile, Lambda) operating at an 810-nm wavelength (1 W of output power, continuous wave of 66.7 J/cm2) that was equipped with a 0.6-mm optical fiber in continuous-wave mode. The canine retraction was accomplished by using prefabricated coil springs. The right of the mandible was chosen to be irradiated with the laser, whereas the left side was considered the control without laser irradiation. The laser was applied with 0-, 3-, 7-, and 14-day intervals. The amount of canine retraction was measured with a digital electronic caliper while the pain level was prompted by a patient questionnaire. The speed of tooth movement was significantly greater in the laser group than in the control group. The pain intensity was also at a lower level in the laser group. Our findings suggest that diode laser therapy can highly accelerate tooth movement during orthodontic treatment and can also effectively reduce pain level.

This work reports measurements of calcified gallstone elemental compositions using laser-induced optical emission spectroscopy. The experimental results support the importance of the magnesium concentration in gallstone growth. Granular stones reveal an increased magnesium concentration at the periphery of the granules, suggesting the inhibition of further growth. Non-granular gallstones reveal lower overall magnesium concentrations but with higher values near the center.