Background: A Few preclinical studies have shown that Knee osteoarthritis (KOA) is linked to gut microbiome dysbiosis and chronic inflammation. This pilot study was designed to look at the gut microbiome composition in KOA patients and normal individuals with or without vitamin D deficiency (VDD, serum vitamin D <30 ng/ml). Methods: This pilot study was conducted prospectively in 24 participants. The faecal samples of all the participants were taken for DNA extraction. The V3-V4 region of 16s rRNA was amplified and the library was prepared and sequenced on the Illumina Miseq platform. Results: The mean (±SD) age was 45.5 (±10.2) years with no defined co-morbidities. Of 447 total Operational Taxonomic Units (OTUs), a differential abundance of 16 nominally significant OTUs between the groups were observed. Linear discriminate analysis (LEfSe) revealed a significant difference in bacteria among the study groups. Pseudobutyrivibrio and Odoribacter were specific for VDD while Parabacteroides, Butyricimonas, and Gordonibacter were abundant in the KOA_VDD group and Peptococcus, Intestimonas, Delftia, and Oribacterium were abundant in the KOA group. About 80% of bacterial species were common among different groups and hence labeled as core bacterial species. However, the core microbiome of KOA and VDD groups were not seen in the KOA_VDD group, suggesting that these bacterial groups were affected by the interaction of the KOA and VDD factors. Conclusion: Parabacteroides, Butyricimonas, Pseudobutyrivibrio, Odoribacter, and Gordonibacter are the predominant bacteria in vitamin D deficient patients with or without KOA. Together these results indicate an association between the gut microbiome, vitamin D, and knee osteoarthritis.

To be used in cutting-edge green and other technologies, rare earth elements (REEs) are in great demand. Rare earth elements (REEs) include the following elements: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; additionally, they include Sc. Computers, laptops, TVs, generators, DVD players, cell phones, refrigerators, and other electronic equipment that are usually thrown away by their original owners because of their limited lifespan are examples of outdated or end-of-life electronics that make up e-waste. At the moment, these metals are essential to many contemporary devices, from LED light bulbs and wind turbines to cell phones and televisions. The development of new, cutting-edge technologies, especially in the field of electronics, depends on the availability of rare earth elements (REEs), sometimes referred to as the "vitamins" of modern industry. Since e-waste frequently has high concentrations of rare earth elements and is handled in hazardous ways, e-waste may be a significant contributor to the contamination of rare earth elements. Apart from their detrimental effects on the environment, these wastes also result in the loss of precious materials and rare earth elements such as gold, silver, copper, platinum, palladium, and rare earth, among other things. Every year, 50 million tonnes of e-waste are created globally. An enormous amount of e-waste is wasted since only 20% of it is handled correctly worldwide. There have been numerous reports on the recovery and separation of rare earth elements (REEs) from e-waste using various techniques, such as the hydrometallurgical process, siderophores, pyrometallurgical process, bioleaching, and biosorption. According to reports, the demand for rare earth elements (REEs) from clean technologies is expected to reach 51.9 thousand metric tons (kt) of REO in 2030. Nd and Dy, on the other hand, make up 75% and 9% of the world's REE deposits, respectively. REE levels in aquatic settings are rising, particularly in urban areas, in tandem with the growing demand for high-tech applications. Urban wastewater from open sewers and the entrance of a wastewater treatment facility in Cotonou, Benin, was collected, and its rare earth element (REE) contamination was evaluated.