PHARMACOGNOSTICAL AND ANTIMICROBIAL STUDIES OF THE STEM OF TABERNAEMONTANA DIVARICATA LINN

Objective: The aim of the present study is to evaluate the pharmacognostic and antimicrobial studies of Tabernaemontana divaricata Linn. Stem.Methods: The Pharmacognostical studies were performed using standard parameters and antimicrobial studies were based on checker board and disc diffusion technique using various bacterial strains. The antifungal studies were based on the agar slant technique.Results: The transverse section shows the presence of undifferentiated cells known as cortex in the outer region. They are followed by an extended part of cortex, which consists of 7-8 layers of Phellogen, followed by 6-7 layers of Phelloderm. The antimicrobial studies confirmed that the methanolic extract was quite effective for bacterial strains Sh. flexneri type BCH 995, Shigella boydii 8, Sh. sonnei NK 840, Sh. dysenteriae 1, Sh. dysenteriae 9, Vibrio cholerae 1023, V. cholerae 1341, V. cholerae 575, V. cholerae 1311, E. coli RH 07/12, E. coli 18/9, E. coli K88, Enterobacter spp AP596, Staphylococcus aureus ML 267, S. aureus MTCC 96, Bacillus subtilis MTCC 441, Pseudomonas auriginosa AP585 NLF, Bacillus pumilus 8241 and Klebsiella pneumoniae. The maximum antibacterial activity was observed against Staphylococcus aureus MTCC 96 (zone of inhibition at 800µg/ml is 12.17±0.124 mm), whereas minimum activity against E. coli RH 07/12 (zone of inhibition at 800µg/ml is 10.45±0.063 mm). It was also effective against the fungal strains Aspergillus niger MTCC 281, Candida albicans ATCC 10231 and Penicillium chrysogenum MTCC 2725.Conclusion: The study of pharmacognostical features of the stem of T. divaricata Linn. May serves as a tool for identification and standardization of the crude drug as per WHO guidelines.Â

Predictors of Severe Acute Malnutrition among Children Aged 6 to 59 Months Attended out Patient Therapeutic Program Center in Kavre District of Nepal - A Case Control Study

Background: Severe acute malnutrition is an excessive loss of weight due to the acute shortage of food or illness. It is one of the major public health problems in developing countries including Nepal. According to multiple indicator cluster survey (MICS) 2014, 2.6% severely malnourished in Nepal and 4.4% are severely malnourished in Kavre district. However, there are limited studies about predictors of severe acute malnutrition in Nepal. Thus, this study was aimed to identify the predictors of severe acute malnutrition in Kavre district of Nepal.Methods: Health facility based matched case control study was conducted among 210 (70 cases and 140 controls) children aged 6-59 months from November 2015 to April 2016. Data was collected through face to face interview with mother of eligible children using structured questionnaires. Multivariate analysis was applied to estimate adjusted odds ratio along with 95% confidence interval.Results: Children with severe acute malnutrition were 11.32 times more likely than control to have recurrent diarrhea in past six months (95% CI=4.64-28.21). Similarly, severe acute malnutrition was associated with female sex (AOR=2.44, 95% CI=1.88-6.78), fathers occupation daily labor (AOR=4.69, 95% CI=1.17-13.76) and agriculture (AOR=6.850, 95%CI=3.81-12.93), improper exclusive breast feeding (AOR=6.646, 95%CI=2.11-20.90), not feeding colostrum (AOR=3.89, 95% CI=2.88-11.21), severe food insecurity access (AOR=3.55, 95% CI=1.85-9.77) and monthly income less than average level (AOR=8.214, 95% CI=1.43-22.16).Conclusion: Severe acute malnutrition was independently associated with sex of child, occupation of father, monthly household income, not feeding colostrum, improper exclusive breast feeding, severe household food insecurity access and recurrent diarrhea

Decade Long Timing Study of the Black Widow Millisecond Pulsar J1544+4937

Results from 11 years of radio timing for eclipsing black widow millisecond pulsar (MSP) binary, J1544+4937, is presented in this paper. We report a phase-connected timing model for this MSP, using observations with the Giant Metrewave Radio Telescope (GMRT) at multiple frequencies and with Green Bank Telescope (GBT). This is the longest-duration timing study of any galactic field MSP with the GMRT. While extending the timing baseline from the existing 1.5 years to about a decade we report the first detection for a significant value of proper motion ($\mathrm{\mu_{T}} \sim$ 10.14(5) $\mathrm{mas/year}$) for this pulsar. Temporal variations of dispersion measure ($\mathrm{\Delta DM~ \sim 10^{-3}}$ pc $\mathrm{cm^{-3}}$) manifested by significant determination of 1st, 2nd, and 3rd order DM derivatives are observed along the line of sight to the pulsar. We also noticed frequency-dependent DM variations of the order of $\mathrm{10^{-3}~ pc~ cm^{-3}}$, which could arise due to spatial electron density variations in the interstellar medium. This study has revealed a secular variation of the orbital period for this MSP for the first time. We investigated possible causes and propose that variation in the gravitational quadrupole moment of the companion could be responsible for the observed temporal changes in the orbital period.Comment: 12 pages, 5 Figures, 2 Table, Accepted in the Astrophysical Journa

Studies on environmental impact of acid mine drainage generation and its treatment : an appraisal

Acid mine drainage is the most significant environmental pollution problem associated with mining industry. The main cause of acid mine drainage is the occurrence of pyrite and sulphide minerals with the rock of coal seams. During mining these sulphide minerals get exposed to air and mine water, then oxidation and hydrolysis results in the generation of acid mine drainage. The low pH value of the discharge mine water results in the future dissolution of minerals and release of toxic metals, when it allowed getting discharge into other water bodies. This acidity and high toxic metals concentration are harmful to the vegetation, aquatic life and wild life. The review paper describes the general chemistry of acid mine drainage generation; its impact on environment: different treatment techniques as remedial and control measures and future trend in treatment technology

Comparative Study of the Oxidation Products of Dimethylglyoxime in Conventional and Microwave Heating Conditions

Abstract: Microwave has proved to be a convenient tool in the hands of chemists for organic synthetic processes in the recent past. In the present work, the products obtained by the oxidation of dimethylglyoxime (DmgH 2 ) in tetrahydrofuran (THF) by ditertiary butyl chromate (TBC) in conventional and microwave dielectric heating conditions are studied. The analysis of the compounds was done by chemical as well as instrumental methods including FTIR and DTA/TGA mass loss pattern. The results clearly indicate that the reactions are much efficient, less energy and time consuming in case of microwave dielectric heating as compared to those in conventional methods

Evaluation of Lipase from an Indigenous Isolated Bacillus Strain for Biodiesel Production

Lipases are utilized in biodiesel production utilizing various types of substrates. The use of lipase in bioenergy production aims to reduce energy crises and environmental pollution. Lipase-producing indigenous bacteria Bacillus licheniformis (Accession no. OP56979) and Bacillus rugosus (Accession no. OP56980) were isolated from various oil-contaminated sites. The isolated potential lipolytic bacteria were screened for maximum lipase production. Then, the bacteria showing the highest lipolytic activity were subjected to identification using the 16s rRNA technique while other isolated were identified biochemically. Lipase [LipBL-WII(c)] from Bacillus licheniformis having the highest lipolytic activity expressed various characteristics. Characterization of crude LipBL-WII(c) expressed that it showed stability in a wide range of pH (4 to 10) with optimum lipolytic activity observed at pH 8. It was then found to be active at a temperature range from 20°C to 80°C with optimal at 50°C. Lipase activity was also stimulated in metal ions such as Ca+1, Mg2+, and Zn2+ the most. Furthermore, LipBL-WII(c) retained lipolytic activity in the presence of various organic solvents and surfactants. The kinetic parameters (Km and Vmax) for LipBL-WII(c) were ascertained using Lineweaver- Burk plot. LipBL-WII(c) showed a potential for biodiesel production using olive oil as a source. Lipase gave 84% yield of biodiesel production from olive oil. Thus, it could be employed as a potential candidate for green biodiesel production using oil sources

Development of a Fast SARS-CoV-2 IgG ELISA, Based on Receptor-Binding Domain, and Its Comparative Evaluation Using Temporally Segregated Samples From RT-PCR Positive Individuals

SARS-CoV-2 antibody detection assays are crucial for gathering seroepidemiological information and monitoring the sustainability of antibody response against the virus. The SARS-CoV-2 Spike protein's receptor-binding domain (RBD) is a very specific target for anti-SARS-CoV-2 antibodies detection. Moreover, many neutralizing antibodies are mapped to this domain, linking antibody response to RBD with neutralizing potential. Detection of IgG antibodies, rather than IgM or total antibodies, against RBD is likely to play a larger role in understanding antibody-mediated protection and vaccine response. Here we describe a rapid and stable RBD-based IgG ELISA test obtained through extensive optimization of the assay components and conditions. The test showed a specificity of 99.79% (95% CI: 98.82-99.99%) in a panel of pre-pandemic samples (n = 470) from different groups, i.e., pregnancy, fever, HCV, HBV, and autoantibodies positive. Test sensitivity was evaluated using sera from SARS-CoV-2 RT-PCR positive individuals (n = 312) and found to be 53.33% (95% CI: 37.87-68.34%), 80.47% (95% CI: 72.53-86.94%), and 88.24% (95% CI: 82.05-92.88%) in panel 1 (days 0-13), panel 2 (days 14-20) and panel 3 (days 21-27), respectively. Higher sensitivity was achieved in symptomatic individuals and reached 92.14% (95% CI: 86.38-96.01%) for panel 3. Our test, with a shorter runtime, showed higher sensitivity than parallelly tested commercial ELISAs for SARS-CoV-2-IgG, i.e., Euroimmun and Zydus, even when equivocal results in the commercial ELISAs were considered positive. None of the tests, which are using different antigens, could detect anti-SARS-CoV-2 IgGs in 10.5% RT-PCR positive individuals by the fourth week, suggesting the lack of IgG response

CONTROL OF CAVITATION USING DISSOLVED CARBON DIOXIDE FOR DAMAGE-FREE MEGASONIC CLEANING OF WAFERS

This dissertation describes the finding that dissolved carbon dioxide is a potent inhibitor of sonoluminescence and describes the implications of the finding in the development of improved megasonic cleaning formulations. Megasonic cleaning, or the removal of contaminants particles from wafer surfaces using sound-irradiated cleaning fluids, has been traditionally used in the semiconductor industry for cleaning of wafers. Recently however, advancing technology and miniaturization has made wafer features increasingly susceptible to damage by megasonic energy. International Technology Roadmap for Semiconductors (ITRS) 2011 predicts the critical particle diameter, critical particle count and killer defect numbers to be 22 nm, 113 #/wafer and 4.3 #/mm², respectively, on a 300 mm wafer for 45 nm technology node. A critical challenge in the field, therefore, is to achieve removal of small particles (22 nm to 200 nm) without causing damage to fine wafer features. The work described here addresses this challenge by identifying sonoluminescence and solution pH as two key factors affecting damage and cleaning efficiency, respectively and establishing novel means to control them using CO₂(aq) release compounds in the presence of acids and bases. Sonoluminescence (SL) behavior of the major dissolved gases such as Ar, Air, N₂, O₂ and CO₂ was determined using a newly designed Cavitation Threshold Cell (CT Cell). SL, which is the phenomenon of release of light in sound-irradiated liquids, is a sensitive indicator of cavitation, primarily transient cavitation. It was found that all the tested dissolved gases such as Ar, Air, N₂ and O₂, generated SL signal efficiently. However, dissolved CO₂ was found to be completely incapable of generating SL signal. Based on this interesting result, gradual suppression of SL signal was demonstrated using CO₂(aq). It was further demonstrated that CO₂(aq) is not only incapable but is also a potent inhibitor of SL. The inhibitory role of CO₂(aq) was established using a novel method of controlled in-situ release of CO₂ from NH₄HCO₃. ~130 ppm CO₂(aq) was shown to be necessary and sufficient for complete suppression of SL generation in air saturated DI water. The method however required acidification of solution for significant release of CO₂, making it unsuitable for the design of cleaning solutions at high pH. Analysis of the underlying ionic equilibria revealed that the loss of released CO₂(aq) upon increase in pH can be compensated by moderate increase in added NH₄HCO₃. Using this method, simultaneous control of SL and solution pH was demonstrated in two systems, NH₄HCO₃/HCl and NH₄OH/CO₂, at two nominal pH values; 5.7 and 7.0. Damage studies were performed on wafer samples with line/space patterns donated by IMEC and FSI International bearing Si/metal/a-Si gate stacks of thickness ~36 nm and Si/Poly-Si gate stacks of thickness ~67 nm, respectively. A single wafer spin cleaning tool MegPie® was used for the generation of megasonic energy for inducing damage to the structures. It was demonstrated that CO₂ dissolution in DI water suppresses damage to the gate stacks in a dose-dependent manner. Together, these studies establish a systematic and strong correlation between CO₂(aq) concentration, SL suppression and damage suppression. Significant damage reduction (~50 % to ~90 %) was observed at [CO₂(aq)] > ~300 ppm. It was also demonstrated that CO₂(aq) suppresses damage under alkaline pH condition too. This demonstration was made possible by the successful design of two new cleaning systems NH₄HCO₃/NH₄OH and CO₂/NH4OH that could generate CO₂(aq) under alkaline conditions. Damage suppressing ability of the newly designed cleaning systems were compared to the standard cleaning system NH₄OH at pH 8.2 and it was found that NH₄HCO₃/NH₄OH and CO₂/NH₄OH systems were 80 % more efficient in suppressing damage compared to the standard NH₄OH cleaning system. Finally, megasonic cleaning studies were conducted in the same single wafer spin cleaning tool MegPie®, using SiO₂ particles (size 185 nm) deposited on 200 mm oxide Si wafers, as the contaminant. It was found that the standard cleaning chemical, NH₄OH, pH 8.2, was effective in achieving > 95 % particle removal for 2 min irradiation of megasonic energy at power densities > 0.7 W/cm². Based on these results, a new system, NH₄HCO₃/NH₄OH, was designed with an aim to release ~300 ppm CO₂ at pH 8.2. It was demonstrated that newly designed system NH₄HCO₃/NH₄OH, allowed significant suppression of damage in comparison to NH₄OH while maintaining > 90 % cleaning efficiency that was comparable to NH₄OH solution, at the same acoustic power densities. Taken together, these studies establish a potent and flexible means for the inhibition of SL generation over a wide pH range and acoustic power densities and demonstrate its use in suppression of wafer damage without compromising megasonic cleaning efficiency.Embargo: Release after 05/24/201

Quantification of the plant terpenome: predicted versus actual emission potentials

Plant essential oils are complex mixtures of volatile organic compounds, which play indispensable roles in communication, defense, and adaptive evolution. The complete chemical library produced by a plant is referred to as its terpenome. The potential biological information stored in essential oil composition data can provide an insight into the silent language of plants, as well as roles of terpene emissions in direct and indirect defense, and for playing a crucial role in adaptive evolution. In this work, we have attempted to measure the plant terpenome from a global perspective. One way of measuring the terpenome is to observe and record actual emissions in natural conditions, and this has been in practice for over a century through variously evolving methods of comprehensive GC–MS and HPLC. An alternative method is a knowledge-based prediction of the terpenome, and this method has gained popularity in recent years, with the advent of large-scale genome sequencing technologies. Over the past decade, our laboratory has been involved in compilation and investigation of the plant terpenome using both these methods and this has offered us the opportunity to compare and contrast data from actual and potential emissions, in order to better understand the terpenome and its roles in primary, secondary and adaptive metabolism. We have used emission data in conjunction with genomic data in order to understand how a plant creates the so-called final terpenome, specific to itself, and whether or not plants tap the complete potential for terpene biosynthesis at their disposal according to their genomes. For measuring actual emissions, we have used EssOilDB (the ESSential OIL DataBase), the largest contextual web resource for phytochemicals and for measuring the total plant potential for emissions, we have used TERZYME, an automated algorithm for identification and analysis of genes and proteins involved in isoprenoid biosynthesis. (PDF) Quantification of the plant terpenome: predicted versus actual emission potentials. Available from: https://www.researchgate.net/publication/310763919_Quantification_of_the_plant_terpenome_predicted_versus_actual_emission_potentials [accessed Jul 10 2018]