Synthesis and Optimization of a Highly Stable and Efficient BN/TiO2 Nanocomposite for Phenol Degradation: A Photocatalytic, Mechanistic and Environmental Impact Study

Different BN/TiO2 nanocomposites were prepared hydrothermally, and their ratio was optimized to get the best photocatalytic performance towards phenol degradation. They were characterized by x-ray photoelectron spectroscopy, x-ray diffraction, Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning and transmission electron microscopies coupled with energy dispersive x-ray units, BET surface area, and UV-Vis diffuse reflectance. The bandgap energy was reduced from 3.35 to 2.95 eV due to the formation of the B-O-Ti bond. This allowed the exploitation of the visible light and inhibited the TiO2 e(-)/h(+) recombination, and consequently, the photocatalytic activity of TiO2 was dramatically improved. Almost 90 % mineralization of 20 ppm phenol solution was achieved within 30 min under simulated sunlight. The as-prepared composite showed excellent stability and reusability. Mechanistic analysis indicated that O2.- and h(+) played a crucial role in phenol degradation. The nanocomposite ' s biocompatibility and environmental impact were evaluated by analyzing its potential toxicity in vivo using the zebrafish embryos. 96-hpf acute toxicity assays, including the mortality rate assay (to obtain the LC50 values) and teratogenic assays (to obtain the No Observed Effect Concentration, NOEC) was conducted. The LC50 value for BN/TiO2 was 482.5 mg L-1, and the NOEC was 100 mg L-1. Based on LC50 value and according to the Fish and Wildlife Service (FWS) acute toxicity rating scale, the photocatalyst is "practically not toxic.

The added value of WES reanalysis in the field of genetic diagnosis: lessons learned from 200 exomes in the Lebanese population

International audienceBackground:The past few decades have witnessed a tremendous development in the field of genetics. Theimplementation of next generation sequencing (NGS) technologies revolutionized the field of molecular biologyand made the genetic information accessible at a large scale. However, connecting a rare genetic variation to acomplex phenotype remains challenging. Indeed, identifying the cause of a genetic disease requires amultidisciplinary approach, starting with the establishment of a clear phenotype with a detailed family history andending, in some cases, with functional assays that are crucial for the validation of the pathogenicity of a mutation.Methods:Two hundred Lebanese patients, presenting a wide spectrum of genetic disorders (neurodevelopmental,neuromuscular or metabolic disorders, etc.), sporadic or inherited, dominant or recessive, were referred, over thelast three and a half years, to the Medical Genetics Unit (UGM) of Saint Joseph University (USJ). In order to identify the genetic basis of these diseases, Whole Exome Sequencing (WES), followed by a targeted analysis, was performed for each case. In order to improve the genetic diagnostic yield, WES data, generated during the first 2 years of this study, were reanalyzed for all patients who were left undiagnosed at the genetic level. Reanalysis was based on updated bioinformatics tools and novel gene discoveries.Results:Our initial analysis allowed us to identify the specific genetic mutation causing the disease in 49.5% of the cases, in line with other international studies. Repeated WES analysis enabled us to increase the diagnostics yield to 56%.Conclusion:The present article reports the detailed results of both analysis and pinpoints the contribution of WES data reanalysis to an efficient genetic diagnosis. Lessons learned from WES reanalysis and interpretation are also shared