Predictive modeling of ion migration induced degradation in perovskite solar cells

With excellent efficiencies being reported from multiple labs across the world, device stability and the degradation mechanisms have emerged as the key aspects that could determine the future prospects of perovskite solar cells. However, the related experimental efforts remain scattered due to the lack of any unifying theoretical framework. In this context, here we provide a comprehensive analysis of ion migration effects in perovskite solar cells. Specifically, we show, for the first time, that (a) the effect of ionic charges is almost indistinguishable from that of dopant ions, (b) ion migration could lead to simultaneous improvement in Voc and degradation in Jsc - a unique observation which is beyond the realm of mere parametric variation in carrier mobility and lifetime, (c) champion devices are more resilient towards the ill effects of ion migration, and finally (d) we propose unique characterization schemes to determine both magnitude and polarity of ionic species. Our results, supported by detailed numerical simulations and direct comparison with experimental data, are of broad interest and provide a much needed predictive capability towards the research on performance degradation mechanisms in perovskite solar cellsComment: 8 pages, 5 figure

EFFECT OF STRESS ON HISTOPATHOLOGY OF MALE REPRODUCTIVE SYSTEM IN RATS

Background: Although relatively little is known about factors affecting fertility. Latest literature suggests that environmental and lifestyle factors play an important role. Recently, oxidative stress has become the focus of interest as potential cause of male infertility. Oxidative stress may play a role in a number of conditions known to be detrimental to male fertility Method: Adult male albino rats weighing 200 - 220 g and aged 12-15 weeks male rats were selected for the study. The rats were randomly analyzed into 3 groups Group 1: Control rat, Group 2: Swimming stress without treatment, Group 3: Treated with vitamin C 30mg/kg/day doses. All rats were subjected to swimming stress daily between 9.00 AM to 10.00 AM until 50 days. Drugs were administered orally for 50 days half an hour before subjecting to stress. At end of the study the reproductive organs testes, seminal vesicles, Vas deferens and prostate were dissected and the samples were used for the histo-pathological evaluation. Result: In stress group section of testis shows seminiferous tubules showed focial poor spermatogenesis with reduction in number of sperm containing seminiferous tubules and absence of spermatozoa was clearly recognized in some seminiferous tubules. Treatment with antioxidant showed recovery but still some of the seminiferous tubules showed decreased spermatozoa. Stress changes in seminal vesicle: the hyperplasia of epithelial lining, histological features of mucosa severely affected and reduced number of gland. Stress induced changes in vas deferens: produced desquamated ling epithelium with atrophic changes and mild exploited epithelium, degenerated basement membrane of vas deferens. Stress induced changes in prostate: Prostatic acini with many papillary folds, desquamated epithelial cells, epithelial proliferation was seen. Conclusion: Oxidative stress produced deleterious effects on male reproductive system and supplementation of antioxidants such as vitamin C have been shown to be protecting effect against the histological changes produced by the oxidative stress on male reproductive system in rats.KEYWORDS:  Stress; Male reproductive organs; Histopathology; Rat

EFFECT OF STRESS ON HISTOPATHOLOGY OF MALE REPRODUCTIVE SYSTEM IN RATS

Background: Although relatively little is known about factors affecting fertility. Latest literature suggests that environmental and lifestyle factors play an important role. Recently, oxidative stress has become the focus of interest as potential cause of male infertility. Oxidative stress may play a role in a number of conditions known to be detrimental to male fertility Method: Adult male albino rats weighing 200 - 220 g and aged 12-15 weeks male rats were selected for the study. The rats were randomly analyzed into 3 groups Group 1: Control rat, Group 2: Swimming stress without treatment, Group 3: Treated with vitamin C 30mg/kg/day doses. All rats were subjected to swimming stress daily between 9.00 AM to 10.00 AM until 50 days. Drugs were administered orally for 50 days half an hour before subjecting to stress. At end of the study the reproductive organs testes, seminal vesicles, Vas deferens and prostate were dissected and the samples were used for the histo-pathological evaluation. Result: In stress group section of testis shows seminiferous tubules showed focial poor spermatogenesis with reduction in number of sperm containing seminiferous tubules and absence of spermatozoa was clearly recognized in some seminiferous tubules. Treatment with antioxidant showed recovery but still some of the seminiferous tubules showed decreased spermatozoa. Stress changes in seminal vesicle: the hyperplasia of epithelial lining, histological features of mucosa severely affected and reduced number of gland. Stress induced changes in vas deferens: produced desquamated ling epithelium with atrophic changes and mild exploited epithelium, degenerated basement membrane of vas deferens. Stress induced changes in prostate: Prostatic acini with many papillary folds, desquamated epithelial cells, epithelial proliferation was seen. Conclusion: Oxidative stress produced deleterious effects on male reproductive system and supplementation of antioxidants such as vitamin C have been shown to be protecting effect against the histological changes produced by the oxidative stress on male reproductive system in rats.KEYWORDS:  Stress; Male reproductive organs; Histopathology; Rat

Evaluation of antioxidant potential of melatonin in periodontitis with a focus on vitamin C

Background: The present study was done with an objective to evaluate the effect of melatonin as an antioxidant, with a focus on vitamin C, in patients suffering from periodontitis.Methods: This study was conducted jointly in the Department of Periodontics, Rural Dental College, and Department of Pharmacology, PIMS, Loni. Patients suffering from chronic periodontitis, of age between 18 to 65 years of either gender were included in the study, after obtaining a written informed consent. Patients were divided into three Groups. Group A included patients who underwent scaling and root planning (SRP) alone, Group B included patients who underwent SRP and supplemented with vitamin E 200 IU daily at night for 4 weeks. Group C included patients who underwent SRP and supplemented with tablet melatonin 3 mg daily at night for 4 weeks. Estimation of vitamin C was done on day 0, day 30, day 60 and day 90.Results: A total 240 patients were enrolled in the study, 80 in each group. Statistical analysis was done using ‘Z’ test of difference between two sample means for comparison of vitamin C among the three groups. It was observed that, there was a highly significant increase in mean values of vitamin C in group C when compared with group A and group B at 1st, 2nd and 3rd visits (p<0.01).Conclusions: Melatonin acts as an antioxidant in the patients of periodontitis which has positive effect on biochemical parameters of periodontitis, conferring a new facet to the management of periodontitis and an attempt to impede the disease progression

Impact of technology transfer for fennel primary processing on income and employment opportunities for tribal women in district Sirohi (Rajasthan)

Krishi Vigyan Kendra organized a set of need based skill oriented training programmes for selected 500 tribal women (fennel producers) in small groups (25-30 trainees) during last four years (2008 to 2012) with an aim to develop their skills regarding harvesting of umbel at post-mature stage, grading of produce (A, B, C &amp; D grades), drying of fennel in modified shade house made up of local indigenous material, threshing on RCC floor or polyether sheet and packaging in polythene lined bags and marketing of the final produce. The skill oriented trainings had a positive impact on tribal women and about half of the total area (50%) has been transformed in primary processing. By primary processing of fennel, additional employment of about one lakh man days have been generated in district Sirohi. By this intervention, additional monetary returns of around Rs. 29.0 crores have been generated in the district. In the district, trained tribal women are getting Rs. 200-250 day-1 for harvesting and primary processing of fennel, whereas other unskilled women are getting only Rs. 100-150 day-1. This intervention has not only improved the living standards of the rural and tribal households but also increased the socio-economic status by providing self employment opportunities and livelihood security. &nbsp

Numerical Simulation for a Multidimensional Fourth-Order Nonlinear Fractional Subdiffusion Model with Time Delay

The purpose of this paper is to develop a numerical scheme for the two-dimensional fourth-order fractional subdiffusion equation with variable coefficients and delay. Using the L2 − 1σ approximation of the time Caputo derivative, a finite difference method with second-order accuracy in the temporal direction is achieved. The novelty of this paper is to introduce a numerical scheme for the problem under consideration with variable coefficients, nonlinear source term, and delay time constant. The numerical results show that the global convergence orders for spatial and time dimensions are approximately fourth order in space and second-order in time. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Acknowledgments: M.A.Z. wishes to acknowledge the support of Nazarbayev University Program 091019CRP2120 and the partial support of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant “Dynamical Analysis and Synchronization of Complex Neural Networks with Its Applications”). M.A.Z. wishes also to acknowledge the financial support of the National Research Centre of Egypt (NRC)

Convergent changes in muscle metabolism depend on duration of high-altitude ancestry across Andean waterfowl

High-altitude environments require that animals meet the metabolic O2 demands for locomotion and thermogenesis in O2-thin air, but the degree to which convergent metabolic changes have arisen across independent high-altitude lineages or the speed at which such changes arise is unclear. We examined seven high-altitude waterfowl that have inhabited the Andes (3812-4806m elevation) over varying evolutionary time scales, to elucidate changes in biochemical pathways of energy metabolism in flight muscle relative to low-altitude sister-taxa. Convergent changes across high-altitude taxa included increased hydroxyacyl-coA dehydrogenase and succinate dehydrogenase activities, decreased lactate dehydrogenase, pyruvate kinase, creatine kinase, and cytochrome c oxidase activities, and increased myoglobin content. ATP synthase activity increased in only the longest established high-altitude taxa, whereas hexokinase activity increased in only newly established taxa. Therefore, changes in pathways of lipid oxidation, glycolysis, and mitochondrial oxidative phosphorylation are common strategies to cope with high-altitude hypoxia, but some changes require longer evolutionary time to arise

Extra-short-duration pigeonpea for diversifying wheat-based cropping systems in the sub-tropics

The performance of newly developed extra-short-duration pigeonpea (Cajanus cajan) genotypes and traditional short-duration pigeonpea cultivars was compared in rotation with wheat in on-farm trials conducted in 1996–97 and 1997–98 in Sonepat (28° N) district in Haryana, and in 1996–97 at Ludhiana (30° N) district in Punjab, India. At both locations, a wheat crop (Triticum aestivum cv. HD 2329) followed pigeonpea. At Sonepat, an indeterminate extra-short-duration genotype ICPL 88039 matured up to three weeks earlier, yet gave 12% higher yield (1.57 t ha−1) and showed less susceptibility to borer damage than did the short-duration cv. Manak. At Ludhiana, extra-short-duration pigeonpea genotypes, ICPL 88039, ICPL 85010 and AL 201 gave similar grain yields to the short-duration T 21 in spite of maturing three to four weeks earlier. Yields of wheat crops following extra-short-duration genotypes were up to 0.75 t ha−1 greater at Sonepat and up to 1.0 t ha−1 greater at Ludhiana. The results of the study provide empirical evidence that extra-short-duration pigeonpea genotypes could contribute to higher productivity of pigeonpea–wheat rotation systems. Most of the farmers who grew on-farm trials in Sonepat preferred extra-short-duration to short-duration pigeonpea types for their early maturity, bold seed size, and the greater yield of the following wheat crop