Phytochemical and Antimicrobial Screening of Native Plant Swertia Chirayita (Roxb. Ex Fleming) Karst From Rasuwa District of Nepal

Swertia chirayita is one of the highly traded medicinal plants of Nepal. This plant was chosen for investigation as folk medicines and then collected from the diverse habitats of Rasuwa district of Nepal and specimens have been checked and identified at National Herbarium and Plant Laboratories (NHPL), Godavari, Lalitpur. The identified plant was subjected to study physiochemical and biological activity. The stem, root and leaves of the plant were dried, made powder and mixed at the ratio of 1 : 1 : 1 and then extracted using methanol solvent by cold and warm method. The percentage yield from the plant was highest in warm methanol with 3.73%, followed by cold methanol with 2.28%. Plant extract showed the presence of phytochemicals like basic alka-loids, coumarin, glycosides, steroids, quinones, flavonoid and terpenoids. The antibacterial activity of the ex-tract showed significant bioactive by inhibiting the growth of selected pathogenic microbial species for the test. The zone of inhibition (ZOI) shown by the extracts was comparable to the standard antibiotics. Similar-ly, proximate composition was also carried out. The antioxidant activity of the sample was found to be 62.54% at 500 µg/mL and 15.32% at 100 µg/mL by radical scavenging method and showed significant antioxi-dants potential

Structural and Physical Properties of CaFe4As3 Single Crystals

We report the synthesis, and structural and physical properties of CaFe4As3 single crystals. Needle-like single crystals of CaFe4As3 were grown out of Sn flux and the compound adopts an orthorhombic structure as determined by X-ray diffraction measurements. Electrical, magnetic, and thermal properties indicate that the system undergoes two successive phase transitions occurring at TN1 ~ 90 K and TN2 ~ 26 K. At TN1, electrical resistivities (\rho(b) and \rho(ac)) are enhanced while magnetic susceptibilities (\chi(b) and \chi(ac)) are reduced in both directions parallel and perpendicular to the b-axis, consistent with the scenario of antiferromagnetic spin-density-wave formation. At TN2, specific heat reveals a slope change, and \chi(ac) decreases sharply but \chi(b) has a clear jump before it decreases again with decreasing temperature. Remarkably, both \rho(b) and \rho(ac) decrease sharply with thermal hysteresis, indicating the first-order nature of the phase transition at TN2. At low temperatures, \rho(b) and \rho(ac) can be described by {\rho} = {\rho}0 + AT^\alpha ({\rho}0, A, and {\alpha} are constants). Interestingly, these constants vary with applied magnetic field. The ground state of CaFe4As3 is discussed.Comment: 15 pages, 8 figures, Submitted to Physical Review

Rising Precipitation Extremes across Nepal

As a mountainous country, Nepal is most susceptible to precipitation extremes and related hazards, including severe floods, landslides and droughts that cause huge losses of life and property, impact the Himalayan environment, and hinder the socioeconomic development of the country. Given that the countrywide assessment of such extremes is still lacking, we present a comprehensive picture of prevailing precipitation extremes observed across Nepal. First, we present the spatial distribution of daily extreme precipitation indices as defined by the Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI) from 210 stations over the period of 1981–2010. Then, we analyze the temporal changes in the computed extremes from 76 stations, featuring long-term continuous records for the period of 1970–2012, by applying a non-parametric Mann−Kendall test to identify the existence of a trend and Sen’s slope method to calculate the true magnitude of this trend. Further, the local trends in precipitation extremes have been tested for their field significance over the distinct physio-geographical regions of Nepal, such as the lowlands, middle mountains and hills and high mountains in the west (WL, WM and WH, respectively), and likewise, in central (CL, CM and CH) and eastern (EL, EM and EH) Nepal. Our results suggest that the spatial patterns of high-intensity precipitation extremes are quite different to that of annual or monsoonal precipitation. Lowlands (Terai and Siwaliks) that feature relatively low precipitation and less wet days (rainy days) are exposed to high-intensity precipitation extremes. Our trend analysis suggests that the pre-monsoonal precipitation is significantly increasing over the lowlands and CH, while monsoonal precipitation is increasing in WM and CH and decreasing in CM, CL and EL. On the other hand, post-monsoonal precipitation is significantly decreasing across all of Nepal while winter precipitation is decreasing only over the WM region. Both high-intensity precipitation extremes and annual precipitation trends feature east−west contrast, suggesting significant increase over the WM and CH region but decrease over the EM and CM regions. Further, a significant positive trend in the number of consecutive dry days but significant negative trend in the number of wet (rainy) days are observed over the whole of Nepal, implying the prolongation of the dry spell across the country. Overall, the intensification of different precipitation indices over distinct parts of the country indicates region-specific risks of floods, landslides and droughts. The presented findings, in combination with population and environmental pressures, can support in devising the adequate region-specific adaptation strategies for different sectors and in improving the livelihood of the rural communities in Nepal

A NOVEL CORE-COAT CHRONOTHERAPEUTIC TECHNIQUE FOR EFFECTIVE DELIVERY OF ANTIHYPERTENSIVE DRUG

Objective: The objective of the work was to formulate coated microbeads using core-coat technique for chronotherapeutic delivery of Carvedilol (cd).Methods: Sodium alginate microbeads containing cd was formulated by ionic gelation method using calcium chloride as a gelling agent. Microbeads were then coated with acrylcoat L 100 (acL 100), acrylcoat S 100 (acS 100), ethyl cellulose (EC), and acrylcoat E30 D (acE 30D) in different ratio. Formulated batches were evaluated using FTIR, particle size measurement, percent entrapment efficiency, micrometric properties, swelling studies, loose surface crystal studies, percentage moisture loss. The formulations were then subjected to in vitro dissolution studies. Cumulative release data was then subjected to different dissolution models reported in the literature.Results: Formulated batches of microbeads were within acceptable particle size range with good to fair flow properties. Entrapment efficiency was in the range of 64% to 99.52%. Loose surface crystal study revealed successful drug entrapment within a range of 2.11 to 9.93%. Swelling studies revealed maximum swelling in alkaline phosphate buffer pH 7.4 solution and percentage moisture loss was within 0.24% to 7.55%. SEM showed microbeads to be spherical in nature and FTIR study exhibited compatibility among the drug and polymer. In vitro release study was carried out for first 3 h in 0.1N HCl and subsequently for 7 h in phosphate buffer solution pH 7.4. Formulation code AC3, AC4, LA4 and LA6 were found in line with our objective of chronotherapeutic drug delivery.Conclusion: Sodium alginate beads loaded with cd and coated with different ratios of coating solutions were successfully formulated and evaluated to optimize the best possible combinations of the coat-core ratio for chronotherapeutic delivery

Tissue-specific regulation of translational readthrough tunes functions of the traffic jam transcription factor

Translational readthrough (TR) occurs when the ribosome decodes a stop codon as a sense codon, resulting in two protein isoforms synthesized from the same mRNA. TR has been identified in several eukaryotic organisms; however, its biological significance and mechanism remain unclear. Here, we quantify TR of several candidate genes in Drosophila melanogaster and characterize the regulation of TR in the large Maf transcription factor Traffic jam (Tj). Using CRISPR/Cas9-generated mutant flies, we show that the TR-generated Tj isoform is expressed in a subset of neural cells of the central nervous system and is excluded from the somatic cells of gonads. Control of TR in Tj is critical for preservation of neuronal integrity and maintenance of reproductive health. The tissue-specific distribution of a release factor splice variant, eRF1H, plays a critical role in modulating differential TR of leaky stop codon contexts. Finetuning of gene regulatory functions of transcription factors by TR provides a potential mechanism for cell-specific regulation of gene ex-pression

Rising mean and extreme near-surface air temperature across Nepal

Owing to unique topographic and ecological diversity, central Himalayan state of Nepal is exposed to adverse impacts of climate change and associated disasters. However, countrywide historical assessment of mean and extreme temperature changes, a prerequisite for devising adequate adaptation strategies, is still lacking. Here, we present a comprehensive picture of mean and extreme temperature trends across Nepal over the 1980–2016 period, based on high-quality daily temperature observations from 46 stations. Our results suggest that besides winter cooling in southern lowlands, the country features a widespread warming, which is higher for maximum temperature (~0.04°C⋅year−1) than for minimum temperature (~0.02°C⋅year−1), over the mountainous region than in valleys and lowlands and during the pre-monsoon season than for the rest of the year. Consistently, we found a higher increasing trend for warm days (13 days⋅decade−1) than for warm nights (4 days⋅decade−1), whereas the rates of decrease for cold days and cold nights are the same (6 days⋅decade−1). Further investigations reveal that pronounced warming in maximum temperature over mountain regions can be attributed to less cloud cover and snowfall in recent decades during non-monsoon seasons as a result of positive geopotential height anomalies and strengthening of anticyclonic circulations in the mid-to-upper troposphere. Similarly, increased stability of lower atmosphere during winter and post-monsoon seasons caused prolonged and frequent periods of fog over lowlands, resulting in significant winter cooling there. © 2019 The Authors. International Journal of Climatology published by John Wiley & Sons Ltd on behalf of the Royal Meteorological Society