Degradation of bisphenol A: a contaminant of emerging concern, using catalytic ozonation by activated carbon impregnated nanocomposite-bimetallic catalyst.

Rampant water pollution events and rising water demand caused by exponential population growth and depleting freshwater resources speak of an impending water crisis. The inability of conventional wastewater treatment systems to remove contaminants of emerging concern (CECs) such as bisphenol A (BPA) beckons for new and efficient technologies to remove them from wastewater and water sources. Advanced oxidation processes such as ozonation are primarily known for their capability to oxidize and degrade organic entities in water, but optimum mineralization levels were hard to achieve. In this study, we synthesized an activated carbon impregnated nanocomposite-bimetallic catalyst (AC/CeO2/ZnO) and used it along with ozonation to remove BPA from water. The catalyst was characterized using BET, XRD, FESEM, Raman spectra, and DLS studies. Catalytic ozonation achieved TOC removal 25% higher than non-catalytic ozonation process. The degradation pathway of BPA was proposed using LC-MS/LC-Q-TOF studies that found six main aromatic degradation byproducts. Catalytic ozonation and non-catalytic ozonation followed similar degradation pathways. The formation of persistent aliphatic acidic byproducts in the treated sample made total organic carbon (TOC) removal above 61% difficult.

Expression of insulin like growth factor binding protein-5 in drug induced human gingival overgrowth.

BACKGROUND & OBJECTIVE: Insulin like growth factor binding proteins (IGFBPs) control the distribution, function and activity of insulin like growth factors (IGFs) in various cells, tissues and body fluids, thereby modulating their metabolic and mitogenic effects. IGFBP-5, the most conserved IGFBP, can function through IGF or directly play a role in fibrosis. Cyclosporine A (CsA) widely used in organ transplant patients, often causes various side effects including gingival fibrotic overgrowth. This study was carried out to assess the mRNA expression of IGFBP-5 in healthy human gingival, chronic periodontitis and CsA induced gingival overgrowth tissues. METHODS: Total RNA was isolated from gingival tissues collected from eight patients with chronic periodontitis, eight patients with CsA induced gingival outgrowth and an equal number of healthy individuals, and subjected to reverse transcription (RT)-PCR for IGFBP-5 gene expression. RESULTS: CsA induced gingival overgrowth tissues expressed increased IGFBP-5 mRNA compared to control and chronic periodontitis. INTERPRETATION & CONCLUSION: Increased mRNA expression of IGFBP-5 in CsA induced gingival outgrowth tissues may be associated with increased collagen synthesis, thereby promoting fibrogenesis.