Gas-Sensing Mechanisms and Performances of MXenes and MXene-Based Heterostructures.

MXenes are a class of 2D transition-metal carbides, nitrides, and carbonitrides with exceptional properties, including substantial electrical and thermal conductivities, outstanding mechanical strength, and a considerable surface area, rendering them an appealing choice for gas sensors. This manuscript provides a comprehensive analysis of heterostructures based on MXenes employed in gas-sensing applications and focuses on addressing the limited understanding of the sensor mechanisms of MXene-based heterostructures while highlighting their potential to enhance gas-sensing performance. The manuscript begins with a broad overview of gas-sensing mechanisms in both pristine materials and MXene-based heterostructures. Subsequently, it explores various features of MXene-based heterostructures, including their composites with other materials and their prospects for gas-sensing applications. Additionally, the manuscript evaluates different engineering strategies for MXenes and compares their advantages to other materials while discussing the limitations of current state-of-the-art sensors. Ultimately, this review seeks to foster collaboration and knowledge exchange within the field, facilitating the development of high-performance gas sensors based on MXenes.

A Novel Approach for Designing a Sub-Bandgap in CuGa(S,Te)2 Thin Films Assisted with Numerical Simulation of Solar Cell Devices for Photovoltaic Application.

As a well-explored chalcopyrite material, copper gallium sulfide CGS has been considered a potential material for solar cell absorber layers. However, its photovoltaic attributes still require to be improved. In this research, a novel chalcopyrite material, copper gallium sulfide telluride CGST, has been deposited and verified as a thin film absorber layer to fabricate high-efficiency solar cells by experimental testing and numerical simulations. The results display the intermediate band formation in CGST with incorporation of Fe ions. Electrical studies showed enhancement in mobility from 1.181 to 1.473 cm2 V-1 s-1 and conductivity from 2.182 to 5.952 S cm-1 for pure and 0.08 Fe-substituted thin films. The I-V curves display the photoresponse and ohmic nature of the deposited thin films, and the maximum photoresponsivity (0.109 A W-1) was observed for 0.08 Fe-substituted films. Theoretical simulation of the prepared solar cells was carried out using SCAPS-1D software, and the obtained efficiency displayed an increasing trend from 6.14 to 11.07% as the Fe concentration increased from 0.0 to 0.08. This variation in efficiency is attributed to the decrease in bandgap (2.51-1.94 eV) and the formation of an intermediate band in CGST with Fe substitution, which is evidenced in UV-vis spectroscopy. The above revealed results open the way to 0.08 Fe-substituted CGST as a promising candidate as a thin film absorber layer in solar photovoltaic technology.

Evaluation of probiotic properties of Lysinibacillus macroides under in vitro conditions and culture of Cyprinus carpio on growth parameters.

Cyprinus carpio is an important freshwater fish in aquaculture. It was used for the isolation of potential probiotic strain for aquaculture applications. The most dominant strain was isolated on MRS agar from the gastrointestinal (GI) of C. carpio and identified as Lysinibacillus macroides using molecular marker 16S rRNA gene. Various probiotic properties such as acid and bile tolerance and antibiotic susceptibility were analysed under in vitro conditions. Further, formulate pelletized feed using probiotic (L. macroides) in different concentrations (2, 4, 6 and 8%). Rearing of C. carpio was carried out 45 days and fed with formulated feed. The highest length (5.14 ± 0.07 cm) and weight (3.56 ± 0.07 g) of C. carpio fingerlings was recorded in the 8% LM probiotic pelletized feed, while in fingerlings fed with control showed lower in the length (3.02 ± 0.13 cm) and the weight (0.92 ± 0.04 g) on the 45th day of the experiment. Both percentage of weight gain (PWG) and specific growth rate (SGR) were significantly increased (P < 0.05) of C. carpio fingerlings fed with probiotic feed compared to control feed. Hence, the use of probiotic bacteria could be an encouraging alternative feed for future endeavours in the field of aquaculture. In conclusion, L. macroides can serve as probiotic for sustainable, competitive and promising beneficial bacteria to aquaculture industry.

Surveillance of variant mecA gene and analysis of efflux pump in mecA negative MRSA infections.

It has been known from the medical records of Kancheepuram district hospitals that there is a prevalence of Methicillin resistant Staphylococcus aureus strain. Now the recent epidemiology has shown the presence of Methicillin Resistant Staphylococcus aureus even in school going children community individuals. In view of the above situation, Methicillin resistant Staphylococcus aureus screening was undertaken in the above said region. Both samples from hospital sources and school going children were screened for Methicillin Resistant Staphylococcus aureus. The results have shown that the samples had multiantibiotic resistant property along with methicillin resistance. The genomic studies have revealed that there were of positive genomic sequence for mec A and 5 isolates for mecA negative gene sequence. This would assume that even negative mec A genome has the resistant expression. Out of the 5 isolates two isolates have shown the presence of both nor A and qac A/B genes. The above results are discussed with efflux of drugs and future proposal on proteomics.