Application of water quality index for the assessment of suitability of natural sources of water for drinking in rural areas of east Sikkim, India

In Sikkim, especially in the rural areas where there is no supply of treated water for drinking and other domestic uses, natural surface water is the only source. The objective was to assess the water quality of natural sources of water in the rural areas of East Sikkim using a water quality index (WQI) for different seasons. A total of 225 samples, that is, 75 in winter, 75 in summer, and 75 in monsoon were collected from different sources for physicochemical analysis, and a WQI was calculated. The water quality values ranged 32.01-96.71. The results showed that most of the water samples were in poor condition (85.3%) and very few of them were in good condition (2.6%). The water quality of the natural sources indicated that the water is poor-quality and not totally safe for human consumption, and that it needs treatment before consumption

Large area transparent ZnO photodetectors with Au wire network electrodes

Transparent electronics as a futuristic technology are fast growing and expanding beyond conventional optoelectronics. Here we report the fabrication of a large area, visibly transparent ultraviolet (UV) photodetector employing a laser deposited ZnO active layer in between branched Au wire networks, with the latter serving as electrodes due to being transparent in UV as well as visible regions. The Au wire networks were prepared using a crack templating method which is not only cost effective but also enables heterostructuring with simple processes. When compared to Ag contact pads, these wire network electrodes seem to enhance photocurrent collection efficiency resulting in high UV sensitivity at low response times. Importantly, the visible light transparency was as high as 80%

To identify predictors of relapse in cases of alcohol dependence syndrome in relation to life events

Background and Objectives: Relapse is a complex and dynamic phenomenon that appears to be determined by biological, psychological, and social factors and an interaction among these. This study examined the association between demographic variables, clinical parameters, and psychosocial factors that predict the vulnerability to relapse in cases of alcohol dependence syndrome. Materials and Methods: Structured assessments of clinical/demographic parameters, relapse precipitants, life events, and dysfunction were carried out among patients with alcohol dependence syndrome (n = 100) who had relapsed and compared with those (n = 100) who had managed to remain abstinent. Results: Patients who had relapsed were found to have significantly more positive family history of substance use, past history of alcohol-related comorbidity, experienced a higher number of undesirable life events, and higher negative mood states and social anxiety and dysfunction in social, vocational, personal, family, and cognitive spheres compared to patients who had remained abstinent. Conclusions: Relapse in alcohol dependents is an interaction of many factors, and multiple layers of assessment may be required to predict relapse. This study provided further evidence in support of the importance of certain clinical/psychosocial factors in relapse in substance dependence. It provides the basis for investigating the correlates of relapse in a wide range of behavioral and substance use problems

Immobilization of a TiO2-PEDOT:PSS hybrid heterojunction photocatalyst for degradation of organic effluents

Heterojunction photocatalysts have recently emerged for use in degradation of organic pollutants, typically being suspended in effluent solution to degrade it. Post degradation, the catalyst must be removed from the treated solution, which consumes both energy and time. Moreover, the separation of nano catalysts from the treated solution is challenging. In the present work, we explore fabrication of immobilized TiO2-PEDOT:PSS hybrid heterojunction catalysts with the support of a PVA (polyvinyl alcohol) matrix. These photocatalytic films do not require any steps to separate the powdered catalyst from the treated water. While the PVA-based films are unstable in water, their stability could be significantly enhanced by heat treatment, enabling efficient removal of organic effluents like methylene blue (MB) and bisphenol-A (BPA) from the aqueous solution under simulated sunlight irradiation. Over 20 cycles, the heterojunction photocatalyst maintained high photocatalytic activity and showed excellent stability. Hence, an immobilization of the TiO2-PEDOT:PSS hybrid heterojunction is suggested to be beneficial from the viewpoint of reproducible and recyclable materials for simple and efficient wastewater treatment.Funding Agencies|Goran Gustafsson Foundation for Research in Natural Sciences and Medicine [SPG/2021/002867, DST/TMD-EWO/WTI/2K19/EWFH/2019/122]; IUAC [SPG/2021/002867, IUAC/XIII.3A/67304]; Goeran Gustafsson Foundation for Research in Natural Sciences and Medicine [DST/TMD-EWO/WTI/2K19/EWFH/2019/122]</p

Antibiotic susceptibility profile of bacteria isolated from natural sources of water from rural areas of East Sikkim

Background: Contamination of water, food, and environment with antibiotic-resistant bacteria poses a serious public health issue. Objective: The objective was to study the bacterial pollution of the natural sources of water in east Sikkim and to determine the antimicrobial profile of the bacterial isolates. Materials and Methods: A total of 225 samples, 75 each during winter, summer, and monsoon season were collected from the same source in every season for bacteriological analysis by membrane filtration method. Antibiotic susceptibility test was performed using standard disc diffusion method. Results: A total of 19 bacterial species of the genera Escherichia, Klebsiella, Proteus, Salmonella, Shigella, Enterobacter, Citrobacter, Morganella, Pseudomonas, Acinetobacter, Flavobacterium, and Serratia were isolated and their antimicrobial sensitivity tested. Generally, most bacterial isolates except Salmonella and Shigella species were found resistant to commonly used antibiotics such as ampicillin (57.5%), trimethoprim/sulfamethoxaole (39.1%), amoxicillin/clavulanic acid (37.4%), cefixime (34.5%), tetracycline (29.1%), ceftazidime (26.3%), ofloxacin (25.9%), amikacin (8.7%), and gentamicin (2.7%) but sensitive to imipenem and piperacillin/tazobactam. Conclusion: Natural sources of water in east Sikkim are grossly contaminated with bacteria including enteropathogens. The consumption of untreated water from these sources might pose health risk to consumers

Hierarchical Ternary Sulfides as Effective Photocatalyst for Hydrogen Generation Through Water Splitting: A Review on the Performance of ZnIn₂S₄

One of the major aspects and advantages of solar energy conversion is the photocatalytic hydrogen generation using semiconductor materials for an eco-friendly technology. Designing a low-cost efficient material to overcome limited light absorption as well as rapid recombination of photogenerated charge carriers is essential to achieve considerable hydrogen generation. In recent years, sulfide based semiconductors have attracted scientific research interest due to their excellent solar response and narrow band gap. The present review focuses on the recent approaches in the development of hierarchical ternary sulfide based photocatalysts with a special focus on ZnIn2S4. We also observe how the electronic structure of ZnIn2S4 is beneficial for water splitting and the various strategies involved for improving the material efficiency for photocatalytic hydrogen generation. The review places emphasis on the latest advancement/new insights on ZnIn2S4 being used as an efficient material for hydrogen generation through photocatalytic water splitting. Recent progress on essential aspects which govern light absorption, charge separation and transport are also discussed in detail

Large mid-esophageal granular cell tumor: benign versus malignant

Granular cell tumors are rare soft tissue neoplasms, among which only 2% are malignant, arising from nervous tissue. Here we present a case of a large esophageal granular cell tumor with benign histopathological features which metastasized to the liver, but showing on positron emission tomography-computerized tomography standardized uptake value suggestive of a benign lesion

Scaling of extended defects in nano-sized Brownmillerite CaFeO2.5

International audienceWe investigated the formation of extended defects in CaFeO2.5, predominantly appearing as antiphase boundaries (APBs), as a function of the synthesis method and temperature. While CaFeO2.5 is known to adopt an ordered oxygen defect structure showing long range order of the (FeO4)∞ chains in its bulk form, interestingly, we demonstrated that the length of these (FeO4)∞ chains can be considerably scaled down to few nanometers by adopting a modified sol-gel method (low temperature synthesis) while the grain size of the resulting nano-phase CaFeO2.5 is around 50 nm. We discuss the synthesis dependent modulation of the length of APBs, characterized by X-ray diffraction and high resolution TEM, to be at the origin of an amplified switching dynamics of the (FeO4)∞ chains. This can accordingly explain the reduction of the onset temperature for oxygen diffusion to set in from 450 °C for bulk-CaFeO2.5 to 320 °C for nano-CaFeO2.5, as determined by 18O/16O oxygen isotope exchange reaction

Edge enriched cobalt ferrite nanorods for symmetric/asymmetric supercapacitive charge storage

For maximum and efficient charge storage and delivery, porous nanorods with active sites can offer a unique set of advantages. Herein, hierarchically porous (0.2-200 nm) cobalt ferrite (CoFe2O4) nanorods are hydrothermally prepared by tuning oleic acid concentration (100-500 mu L with subsequent annealing (400 degrees C). These hierarchical pores (with edges and cavities) raise the specific surface area of CoFe2O4 nanorods to 154 m(2)g(-1). In addition, 80% of CoFe2O4 sites become accessible boosting the capacitance to a high value (460.5 Fg(-1) at 1.0 Ag-1), while retaining excellent cyclic stability (95.8% for 5000 cycles). Maximum pseudocapacitive contribution from these electrochemically active sites is ensured by rapid diffusion of electrolytic OH- ions (5.8 x 10(-8)cm(2)s(-1)). Moreover, on assembling these nanorods as a positive electrode in asymmetric configuration (graphene nanoribbons as negative electrode), the cell exhibits an outstanding energy density (33.5 Wh kg(-1) at 727.8 W kg(-1)), almost double of its symmetric (16.5 Wh kg(-1) at 288 W kg(-1)) counterpart