141 research outputs found

    Effective utilization of Salvinia molesta D. Mitch. for the production of cellulase enzyme by using Aspergillus species and reuse of fungal biomass for dye degradation

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    The present study reveals Salvinia molesta D. Mitch.in various concentration is used as carbon source for the production of cellulase enzyme using Aspergillus species by submerged fermentation. The basal medium supplemented with Salvinia molesta blend in the proportion of 1:0.5 as carbon source showed maximum cellulase production after 6 days of incubation at room temperature with agitation speed of 150 rpm in rotary shaker, were liberated 3.2mg/ml glucose. Methylene blue dye was completely decolourized within 6 days of incubation at room temperature with agitation speed of 150 rpm. This demonstrates the reuse of fungal biomass for dye degradation after enzyme production

    Effect of substrate roughness on growth of diamond by hot filament CVD

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    Polycrystalline diamond coatings are grown on Si (100) substrate by hot filament CVD technique. We investigate here the effect of substrate roughening on the substrate temperature and methane concentration required to maintain high quality, high growth rate and faceted morphology of the diamond coatings. It has been shown that as we increase the substrate roughness from 0.05 μm to 0.91 μm (Centre Line Average or CLA) there is enhancement in deposited film quality (Raman peak intensity ratio of sp 3 to non-sp 3 content increases from 1.65 to 7.13) and the substrate temperature can be brought down to 640°C without any additional substrate heating. The coatings grown at adverse conditions for sp 3 deposition has cauliflower morphology with nanocrystalline grains and coatings grown under favourable sp 3 condition gives clear faceted grains

    A Simple Power Electronic Interface for Grid Connected PV System Using Multilevel Inverter with Hysteresis Current Control

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    A power electronic interface for grid connected photovoltaic (PV) system using boost converter and multilevel inverter (MLI) has been proposed. The variable dc voltage of the PV array ranging from 60V to 80V is fed as input to the boost converter and the duty ratio of the boost converter is adjusted to obtain the required output voltage of 175V. The boosted voltage of the PV array is given to the MLI, which has the advantage of reduced number of switches. The triggering pulses for IGBT switches in the MLI are given by using Hysteresis Current Controller (HCC) technique. This control strategy is effective to make grid current sinusoidal and to achieve unity power factor.  The proposed scheme is simulated in MATLAB/Simulink and the results are presented. Experimental model of this scheme is developed and the results are compared. This work uses 5 PV panels of 21V, 5A each in series

    Evaluation of noise regression techniques in resting-state fMRI studies using data of 434 older adults

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    Subject motion is a well-known confound in resting-state functional MRI (rs-fMRI) and the analysis of functional connectivity. Consequently, several clean-up strategies have been established to minimize the impact of subject motion. Physiological signals in response to cardiac activity and respiration are also known to alter the apparent rs-fMRI connectivity. Comprehensive comparisons of common noise regression techniques showed that the Independent Component Analysis based strategy for Automatic Removal of Motion Artifacts (ICA-AROMA) was a preferred pre-processing technique for teenagers and adults. However, motion and physiological noise characteristics may differ substantially for older adults. Here, we present a comprehensive comparison of noise-regression techniques for older adults from a large multi-site clinical trial of exercise and intensive pharmacological vascular risk factor reduction. The Risk Reduction for Alzheimer\u27s Disease (rrAD) trial included hypertensive older adults (60-84 years old) at elevated risk of developing Alzheimer\u27s Disease (AD). We compared the performance of censoring, censoring combined with global signal regression, non-aggressive and aggressive ICA-AROMA, as well as the Spatially Organized Component Klassifikator (SOCK) on the rs-fMRI baseline scans from 434 rrAD subjects. All techniques were rated based on network reproducibility, network identifiability, edge activity, spatial smoothness, and loss of temporal degrees of freedom (tDOF). We found that non-aggressive ICA-AROMA did not perform as well as the other four techniques, which performed table with marginal differences, demonstrating the validity of these techniques. Considering reproducibility as the most important factor for longitudinal studies, given low false-positive rates and a better preserved, more cohesive temporal structure, currently aggressive ICA-AROMA is likely the most suitable noise regression technique for rs-fMRI studies of older adults

    Shallow water marine sediment bacterial community shifts along a natural CO2 gradient in the Mediterranean Sea off Vulcano, Italy.

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    The effects of increasing atmospheric CO(2) on ocean ecosystems are a major environmental concern, as rapid shoaling of the carbonate saturation horizon is exposing vast areas of marine sediments to corrosive waters worldwide. Natural CO(2) gradients off Vulcano, Italy, have revealed profound ecosystem changes along rocky shore habitats as carbonate saturation levels decrease, but no investigations have yet been made of the sedimentary habitat. Here, we sampled the upper 2 cm of volcanic sand in three zones, ambient (median pCO(2) 419 μatm, minimum Ω(arag) 3.77), moderately CO(2)-enriched (median pCO(2) 592 μatm, minimum Ω(arag) 2.96), and highly CO(2)-enriched (median pCO(2) 1611 μatm, minimum Ω(arag) 0.35). We tested the hypothesis that increasing levels of seawater pCO(2) would cause significant shifts in sediment bacterial community composition, as shown recently in epilithic biofilms at the study site. In this study, 454 pyrosequencing of the V1 to V3 region of the 16S rRNA gene revealed a shift in community composition with increasing pCO(2). The relative abundances of most of the dominant genera were unaffected by the pCO(2) gradient, although there were significant differences for some 5 % of the genera present (viz. Georgenia, Lutibacter, Photobacterium, Acinetobacter, and Paenibacillus), and Shannon Diversity was greatest in sediments subject to long-term acidification (>100 years). Overall, this supports the view that globally increased ocean pCO(2) will be associated with changes in sediment bacterial community composition but that most of these organisms are resilient. However, further work is required to assess whether these results apply to other types of coastal sediments and whether the changes in relative abundance of bacterial taxa that we observed can significantly alter the biogeochemical functions of marine sediments

    Prevalence, distribution and correlates of tobacco smoking and chewing in Nepal: a secondary data analysis of Nepal Demographic and Health Survey-2006

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    <p>Abstract</p> <p>Background</p> <p>Nearly four-fifths of estimated 1.1 million smokers live in low or middle-income countries. We aimed to provide national estimates for Nepal on tobacco use prevalence, its distribution across demographic, socio-economic and spatial variables and correlates of tobacco use.</p> <p>Methods</p> <p>A secondary data analysis of 2006 Nepal Demographic and Health Survey (DHS) was done. A representative sample of 9,036 households was selected by two-stage stratified, probability proportional to size (PPS) technique. We constructed three outcome variables 'tobacco smoke', 'tobacco chewer' and 'any tobacco use' based on four questions about tobacco use that were asked in DHS questionnaires. Socio-economic, demographic and spatial predictor variables were used. We computed overall prevalence for 'tobacco smoking', 'tobacco chewing' and 'any tobacco use' i.e. point estimates of prevalence rates, 95% confidence intervals (CIs) after adjustment for strata and clustering at primary sampling unit (PSU) level. For correlates of tobacco use, we used multivariate analysis to calculate adjusted odds ratios (AORs) and their 95% CIs. A p-value < 0.05 was considered as significant.</p> <p>Results</p> <p>Total number of households, eligible women and men interviewed was 8707, 10793 and 4397 respectively. The overall prevalence for 'any tobacco use', 'tobacco smoking' and 'tobacco chewing' were 30.3% (95% CI 28.9, 31.7), 20.7% (95% CI 19.5, 22.0) and 14.6% (95% CI 13.5, 15.7) respectively. Prevalence among men was significantly higher than women for 'any tobacco use' (56.5% versus 19.6%), 'tobacco smoking' (32.8% versus 15.8%) and 'tobacco chewing' (38.0% versus 5.0%). By multivariate analysis, older adults, men, lesser educated and those with lower wealth quintiles were more likely to be using all forms of tobacco. Divorced, separated, and widowed were more likely to smoke (OR 1.49, 95% CI 1.14, 1.94) and chew tobacco (OR 1.36, 95% CI 0.97, 1.93) as compared to those who were currently married. Prevalence of 'tobacco chewing' was higher in eastern region (19.7%) and terai/plains (16.2%). 'Tobacco smoking' and 'any tobacco use' were higher in rural areas, mid-western and far western and mountainous areas.</p> <p>Conclusions</p> <p>Prevalence of tobacco use is considerably high among Nepalese people. Demographic and socioeconomic determinants and spatial distribution should be considered while planning tobacco control interventions.</p

    Social disparities in the use of colonoscopy by primary care physicians in Ontario

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    <p>Abstract</p> <p>Background</p> <p>It is unclear if all persons in Ontario have equal access to colonoscopy. This research was designed to describe long-term trends in the use of colonoscopy by primary care physicians (PCPs) in Ontario, and to determine whether PCP characteristics influence the use of colonoscopy.</p> <p>Methods</p> <p>We conducted a population-based retrospective study of PCPs in Ontario between the years 1996-2005. Using administrative data we identified a screen-eligible group of patients aged 50-74 years in Ontario. These patients were linked to the PCP who provided the most continuous care to them during each year. We determined the use of any colonoscopy among these patients. We calculated the rate of colonoscopy for each PCP as the number of patients undergoing colonoscopies per 100 screen eligible patients. Negative binomial regression was used to identify factors associated with the rate of colonoscopy, using generalized estimating equations to account for clustering of patients within PCPs.</p> <p>Results</p> <p>Between 7,955 and 8,419 PCPs in Ontario per year (median age 43 years) had at least 10 eligible patients in their practices. The use of colonoscopy by PCPs increased sharply in Ontario during the study period, from a median rate of 1.51 [inter quartile range (IQR) 0.57-2.62] per 100 screen eligible patients in 1996 to 4.71 (IQR 2.70-7.53) in 2005. There was substantial variation between PCPs in their use of colonoscopy. PCPs who were Canadian medical graduates and with more years of experience were more likely to use colonoscopy after adjusting for their patient characteristics. PCPs were more likely to use colonoscopy if their patient populations were predominantly women, older, had more illnesses, and if their patients resided in less marginalized neighborhoods (lower unemployment, fewer immigrants, higher income, higher education, and higher English/French fluency).</p> <p>Conclusions</p> <p>There is substantial variation in the use of colonoscopy by PCPs, and this variation has increased as the overall use of colonoscopy increased over time. PCPs whose patients were more marginalized were less likely to use colonoscopy, suggesting that there are inequities in access.</p

    Genetic Diversity of the ORF5 Gene of Porcine Reproductive and Respiratory Syndrome Virus Isolates in Southwest China from 2007 to 2009

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    To gain insight into the molecular epidemiology and possible mechanisms of genetic variation of porcine reproductive and respiratory syndrome (PRRS) in Yunnan Province of China, the ORF5 gene of 32 PRRSV isolates from clinical samples collected from 2007 to 2009 were sequenced and analyzed. Nucleotide and amino acid analyses were carried out on 32 isolates and representative strains of the North American genotype, European genotype and two representative Chinese isolates. Results revealed that these isolates share 86.9–99.0% nucleotide and 87.5–98.0% amino acid identity with VR-2332 the prototypical North American PRRSV, 61.7–62.9% and 54.3–57.8% with Lelystad virus (LV) the representative strain of European genotype, 91.2–95.4% and 90.0–94.5% with CH-1a that was isolated in mainland China in 1996, 88.1–99.3% and 85.5–99.0% with JX-A1 the representative strain of High pathogenic PRRSV in China, and 86.2–99.8% and 85.5–100.0% between isolated strains of different years, respectively. Phylogenetic analysis revealed that all 32 PRRSV isolates belonged to the North American genotype and were further divided into two different subgenotypes. Subgenotype 1 comprised twenty two Yunnan isolates which divided into two branches. Subgenotype 2 comprised ten isolates which closely related to the RespPRRS vaccine and its parent strain VR-2332. The functional domains of GP5 such as the signal peptide, ectodomain, transmembrane regions and endodomain were identified and some motifs in GP5 with known functions, such as primary neutralizing epitope (PNE) and decoy epitope were also further analyzed. Our study shown the great genetic diversity of PRRSV in southwest China, rendering the guide for control and prevention of this disease

    De Novo Design and Synthesis of Ultra-Short Peptidomimetic Antibiotics Having Dual Antimicrobial and Anti-Inflammatory Activities

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    Ravichandran N. Murugan, Mija Ahn, Eunha Hwang, Ji-Hyung Seo, Chaejoon Cheong, Jeong Kyu Bang, Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of KoreaBinu Jacob, Song Yub Shin, Department of Bio-Materials, Graduate School and Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju, Republic of KoreaHoik Sohn, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas, United States of AmericaHyo-Nam Park, Jae-Kyung Hyun, Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon, Republic of KoreaEunjung Lee, Ki-Woong Jeong, Yangmee Kim, Department of Bioscience and Biotechnology, Institute of SMART Biotechnology, Konkuk University, Seoul, Republic of KoreaKy-Youb Nam, Bioinformatics and Molecular Design Research Center, Yonsei University Research Complex, Seoul, Republic of KoreaBackground: Much attention has been focused on the design and synthesis of potent, cationic antimicrobial peptides (AMPs) that possess both antimicrobial and anti-inflammatory activities. However, their development into therapeutic agents has been limited mainly due to their large size (12 to 50 residues in length) and poor protease stability.-- Methodology/Principal Findings: In an attempt to overcome the issues described above, a set of ultra-short, His-derived antimicrobial peptides (HDAMPs) has been developed for the first time. Through systematic tuning of pendant hydrophobic alkyl tails at the N(Ï€)- and N(Ï„)-positions on His, and the positive charge of Arg, much higher prokaryotic selectivity was achieved, compared to human AMP LL-37. Additionally, the most potent HDAMPs showed promising dual antimicrobial and anti-inflammatory activities, as well as anti–methicillin-resistant Staphylococcus aureus (MRSA) activity and proteolytic resistance. Our results from transmission electron microscopy, membrane depolarization, confocal laser-scanning microscopy, and calcein-dye leakage experiments propose that HDAMP-1 kills microbial cells via dissipation of the membrane potential by forming pore/ion channels on bacterial cell membranes. -- Conclusion/Significance: The combination of the ultra-short size, high-prokaryotic selectivity, potent anti-MRSA activity, anti-inflammatory activity, and proteolytic resistance of the designed HDAMP-1, -3, -5, and -6 makes these molecules promising candidates for future antimicrobial therapeutics.This work was supported in part by the Korea Basic Science Institute's research program grants T33418 (J.K.B) and T33518 (J-k.H.), and the Korea Research Foundation, funded by the Korean Government (KRF-2011-0009039 to S.Y.S.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.ChemistryBiochemistryEmail: [email protected] (JKB)Email: [email protected] (SYS
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