An Environmentally Stable and Lead-Free Chalcogenide Perovskite

Organic-inorganic halide perovskites are intrinsically unstable when exposed to moisture and/or light. Additionally, the presence of lead in many perovskites raises toxicity concerns. Herein is reported a thin film of BaZrS3, a lead-free chalcogenide perovskite. Photoluminescence and X-ray diffraction measurements show that BaZrS3 is far more stable than methylammonium lead iodide (MAPbI3) in moist environments. Moisture- and light-induced degradations in BaZrS3 and MAPbI3 are compared by using simulations and calculations based on density functional theory. The simulations reveal drastically slower degradation in BaZrS3 due to two factors - weak interaction with water, and very low rates of ion migration. BaZrS3 photo-detecting devices with photo-responsivity of ~46.5 mA W-1 are also reported. The devices retain ~60% of their initial photo-response after 4 weeks in ambient conditions. Similar MAPbI3 devices degrade rapidly and show ~95% decrease in photo-responsivity in just 4 days. The findings establish the superior stability of BaZrS3 and strengthen the case for its use in optoelectronics. New possibilities for thermoelectric energy conversion using these materials are also demonstrated

Formulation And Characterization Of Buccal Patches Of Dapagliflozin Using Box–Behnken Design

Buccal drug delivery has emerged as a promising approach for the systemic delivery of various therapeutic agents, offering several advantages over conventional oral administration routes (Dhiman et al., 2020). Buccal patches, in particular, provide controlled release of drugs, enhanced bioavailability, avoidance of hepatic first-pass metabolism, and improved patient compliance. Dapagliflozin, a selective sodium-glucose co-transporter 2 (SGLT2) inhibitor, is widely used in the management of type 2 diabetes mellitus. Formulation and characterization of buccal patches of dapagliflozin represent a novel strategy to enhance drug delivery and therapeutic efficacy. The development of optimized buccal patches can address challenges associated with the oral administration of dapagliflozin, such as variable absorption, gastrointestinal side effects, and dosing frequency

Fundamentals of Stock Returns in Nepal

The report explores fundamental financial variables that influence stock price performance of commercial banks performing on Nepal Stock Exchange (NEPSE). Stock return analysis during 2005-2020 for nine banks spanning 15 years utilizes financial indicator measures that link earnings yield with firm size and book-to-market ratio and cash flow yield to establish relationships. Results show total yield performs positively regarding firm size and book-to-market ratio but negatively regarding earnings per share based on econometrics. The research does not show any meaningful statistical relationship between stock returns and values of cash flow yield. Basic financial performance measures work as vital elements which affect the ability to predict stock returns in Nepal's developing financial market structure. The analysis delivers useful information to financial policymakers and investors because book-to-market ratios and firm size strongly influence stock returns despite conflicting evidence regarding earnings yield and cash flow yield performances. New patterns of emerging market stock returns become clearer through this research as the findings help financial markets with practical decision making and policy needs

Interaction of driven "cold" electron plasma wave with thermal bulk mediated by spatial ion inhomogeneity

Using high resolution Vlasov - Poisson simulations, evolution of driven ``cold" electron plasma wave (EPW) in the presence of stationary inhomogeneous background of ions is studied. Mode coupling dynamics between ``cold'' EPW with phase velocity $v_{\phi}$ greater than thermal velocity i.e $v_{\phi} \gg v_{thermal}$ and its inhomogeneity induced sidebands is illustrated as an initial value problem. In driven cases, formation of BGK like phase space structures corresponding to sideband modes due to energy exchange from primary mode to bulk particles via wave-wave and wave-particle interactions leading to particle trapping is demonstrated for inhomogeneous plasma. Qualitative comparison studies between initial value perturbation and driven problem is presented, which examines the relative difference in energy transfer time between the interacting modes. Effect of variation in background ion inhomogeneity amplitude as well as ion inhomogeneity scale length on the driven EPWs is reported

Sequential two electron photooxidation of t-amines: generation of a regiospecific iminium cation and its application in organic synthesis

PET activation of cyclic t-amines, utilizing 9, 10-dicyanonaphthalene (DCN) as light absorbing electron acceptor in aqueous acetonitrile solution, leads to the generation of iminium cation intermediate involving electron - proton - electron (E-P-E) transfer sequence. Iminium cation generation is found to be highly regiospecific and depends upon the kinetic acidity which is subject to the stereoelectronic factor of the α -C-H proton of the unymmetrical t-amines. Tetrahydro-1, 3-oxazines (6) are synthesized in complete regio-and stereoselective manner from the PET activation of the substrates of type 4. Nucleophilic alkylation of 6 by alkyl Grignard reagents provides cis- α, α'-dialkyl cyclic amines (8). Similarly, chiral perhydropyrido[2,1-b][1, 3, 4]-oxadiazinone (11) is synthesized as a precursor for the synthesis of optically active α-alkyl piperidines. Both enantiomers of hemlock alkaloid coniine (13) are also synthesized. Furthermore, to broaden the scope of these reactions, precursor 16 is designed for the synthesis of various α-amino acids and their N-alkyl derivatives

Design of a photosystem to harvest visible-light into electrons: photosensitised one electron redox reactions in organic synthesis

Based on synchronous oxidation-reduction processes, analogous to photosynthetic mechanistic paradigm, a photosystem utilising Ph3P or ascorbic acid as sacrificial electron donor has been developed to halvest electrons from visible light photons. The utility of such photosystem has been demonstrated by initiating various one-electron reductive -C-C-bo nd formation reactions. Biologically active PGE1, and C-Furanosides are synthesised employing this photosystem at a crucial step

Management of Treatment and Prevention of Acute OP Pesticide Poisoning by Medical Informatics, Telemedicine and Nanomedicine

Acute organophosphorous pesticide (OP) poisoning kills a lot of people each year. Treatment of acute OP poisoning is of very difficult task and is a time taking event. Present day informatics methods (telemedicine), bioinformatics methods (data mining, molecular modeling, docking, cheminformatics), and nanotechnology (nanomedicine) should be applied in combination or separately to combat the rise of death rate due to OP poisoning. Use of informatics method such as Java enabled camera mobiles will enable us early detection of insecticidal poisoning. Even the patients who are severely intoxicated (suicidal attempts) can be diagnosed early. Telemedicine can take care for early diagnosis and early treatment. Simultaneously efforts must be taken with regard to nanotechnology to find lesser toxic compounds (use less dose of nanoparticle mediated compounds: nano-malathion) as insecticides and find better efficacy of lesser dose of compounds for treatment (nano-atropine) of OP poisoning. Nano-apitropine (atropine oxide) may be a better choice for OP poisoning treatment as the anticholinergic agent; apitropine and hyoscyamine have exhibited higher binding affinity than atropine sulfate. Synthesis of insecticides (malathion) with an antidote (atropine, apitropine) in nanoscale range will prevent the lethal effect of insecticides