Electrochemical oxygen reduction reaction (ORR) via nonprecious catalysts has the potential for significant cost reduction in fuel cells. Dense, multi-layered poly(vinyl) alcohol (PVA) nanofibers dispersed with catalytically active carbon nitride (CN x ) nanoparticles were synthesized using electrospinning process. Size, morphology, elemental composition, bond structure of the CN x /PVA nanofibers were analysed using TEM, SEM, FTIR, XPS and Raman spectroscopic studies. Significant improvement in the electrocatalytic activity of CN x nanoparticles dispersed in the nanofibers as compared to its native form was observed towards ORR by voltammetry coupled with FTIR studies. Onset potential and peak current density observed for CN x /PVA nanofibers using cyclic voltammetry was comparable to conventional Pt/C (40:60 % by weight) catalyst. ORR mechanism was further analysed using RRDE and in-situ FTIR with linear sweep voltammetry studies. RRDE analysis confirmed that ORR takes place primarily via 4-electron pathway. The catalytic activity of CN x /PVA nanofibers for ORR was stable over 5000 repetitions of voltammetric studies coupled with FTIR.

Abstract

Facile surfactant-free microfluidic synthesis of zinc oxide (ZnO) nanostructures with varying morphology (spindles, sheets and spheres) has been achieved using polydimethylsiloxane microreactors having different channel geometry. Synthesized ZnO nanostructures show excellent photocatalytic dye degradation efficiency (>80%) when investigated using fixed bed photocatalytic microreactors under UV radiation.

No abstract

The evolving dynamics of drug resistance due to tumor heterogeneity often creates impediments to traditional therapies making it a challenging issue for cancer cure. Breast cancer often faces challenges of current therapeutic interventions owing to its multiple complexities and high drug resistivity， for example against drugs like trastuzumab and tamoxifen. Drug resistance in the majority of breast cancer is often aided by the overtly expressed P-glycoprotein (P-gp) that guides in the rapid drug efflux of chemotherapy drugs. Despite continuous endeavors and ground-breaking achievements in the pursuit of finding better cancer therapeutic avenues, drug resistance is still a menace to hold back. Among newer therapeutic approaches, the application of phytonutrients such as alkaloids to suppress P-gp activity in drug-resistant cancers has found an exciting niche in the arena of alternative cancer therapies. In this work, we would like to present a black pepper alkaloid derivative known as BioPerine-loaded chitosan (CS)-polyethylene glycol (PEG) coated polylactic acid (PLA) hybrid polymeric nanoparticle to improve the bioavailability of BioPerine and its therapeutic efficacy in suppressing P-gp expression in MDA-MB 453 breast cancer cell line. Our findings revealed that the CS-PEG-BioPerine-PLA nanoparticles demonstrated a smooth spherical morphology with an average size of 316 nm, with improved aqueous solubility, and provided sustained BioPerine release. The nanoparticles also enhanced in vitro cytotoxicity and downregulation of P-gp expression in MDA-MB 453 cells compared to the commercial inhibitor verapamil hydrochloride, thus promising a piece of exciting evidence for the development of BioPerine based nano-drug delivery system in combination with traditional therapies as a crucial approach to tackling multi-drug resistance in cancers.