ABSTRACT
Different modes of attachment of graphene oxide (GO) on an electrode surface resulted in unusual catalytic behavior respective of attachment because of film thickness. The present work investigates the direct adsorption of GO to the surface of a glassy carbon (GC) electrode. Scanning electron microscopy images revealed that multilayers of GO get adsorbed on the GC substrate and the adsorption was limited by folding up of the GO sheets at their edges. π-π and hydrogen bonding interactions between the GO and GC substrate flagged the adsorption of GO. pH studies revealed that higher adsorption of GO was achieved at pH = 3 rather than at pH = 7 and 10. Even though the electroactive surface area of adsorbed GO (GOads) was not remarkable (0.069 cm2), upon electrochemical reduction of GOads (Er-GOads), the electroactive surface area was escalated to be 0.174 cm2. Similarly, the RCT of Er-GOads was boosted to 2.9 kΩ compared to GOads which is 19 kΩ. Open circuit voltage was recorded to study the adsorption of GO on the GC electrode. Multilayered GO best fitted with the Freundlich adsorption isotherm, and the Freundlich constants like n and KF were found to be 4 and 0.992, respectively. The Freundlich constant "n" revealed the adsorption of GO on the GC substrate to be a physisorption process. Furthermore, the electrocatalytic performance of Er-GOads was demonstrated by taking uric acid as a probe. The modified electrode showed excellent stability toward the determination of uric acid.
ABSTRACT
To counter the challenge posed by the suspension of face-to-face classes due to COVID-19 imposed restrictions, a plan was formulated to conduct practical physiology classes for first-year undergraduate medical students at a newly established medical college in India. The students were provided with study materials before the scheduled class along with an assignment based on it. The class was taken on an online platform, with live practical demonstration on a full-body mannequin. This was followed by discussion in small groups. This strategy actively engaged both teachers and students and provided an effective model for imparting practical skills on an online platform.
ABSTRACT
Invasive aspergillosis remains a life-threatening infection in immunocompromised patients. Although clinical failures are attributed to poor host immunity, antifungal drug resistance may be a contributing factor. Reports of voriconazole (VRC) resistance (VRC-R) in clinical isolates of Aspergillus spp. continue to emerge from various centers around the world, and mechanisms contributing to drug resistance are poorly understood. The aim of this study is to study the role of multidrug resistance efflux pumps (MDR-EPs) in VRC-R in Aspergillus flavus using efflux pump inhibitors and quantitative reverse transcriptase polymerase chain reaction. Relative quantification of various MDR-EPs was performed pre-exposure and postexposure to VRC, which demonstrated an increase in 1 or more efflux pump gene transcripts to varying degrees in VRC-susceptible and VRC-R isolates of A. flavus. Exposure to sub-MIC of VRC causes up-regulation of genes encoding MDR-EPs, contributing to triazole resistance in A. flavus and may not be detected during routine antifungal susceptibility testing in vitro.
