244 research outputs found

    Synthesis, Antimicrobial Activities of New Sulfonamidobenzoxazoles and Molecular Docking Studies on Escherichia coli TEM-1 β-Lactamase

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    β-Lactam antibiotics are frequently used for treatment of multi-drug resistant microbial infections and the most common mechanism of resistance against these antibiotics is bacterial β-lactamase production. Herein, we reported the design, synthesis and in vitro antimicrobial activities of some new 2-substituted-5-(2,4-dinitrophenylsulfonamido)benzoxazole derivatives. Compounds TN1, TN2, and TN3 were found to be significantly active against E. coli isolate which contains extended spectrum β-lactamase enzyme at the MIC value of 8 µg mL–1 and that is 4-fold higher than the reference drug ampicillin. We performed molecular docking studies into active site of Escherichia coli TEM-1 β-lactamase enzyme in order to predict the protein-ligand interactions. According to the docking results, compounds TN1, TN2, and TN3 showed strong interactions between the important active site residues which are responsible for the catalytic mechanism of TEM-1 β-lactamase enzyme and a good correlation is found with the experimental data. This work is licensed under a Creative Commons Attribution 4.0 International License

    THE EFFECT OF POLYMER TYPE AND FIBER ORIENTATION ON THE COMPLIANCE PROPERTIES OF ELECTROSPUN VASCULAR GRAFTS

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    Vascular diseases are a major source of fatalities globally. However, the lack of accessibility of autologous vessels and the poor efficacy of commercial small-diameter vascular grafts limit surgical alternatives. Researchers therefore aimed to develop vascular prostheses that meet all requirements. Apart from the benefits of tissue-engineered grafts, significant obstacles that still hinder successful grafting include compliance mismatch, dilatation, thrombus development, and the absence of elastin. Among these issues, compliance mismatch between native vessel and artificial vascular scaffold has been mentioned in the literature as a possible cause of intimal hyperplasia, suture site rupture and endothelial and platelet cell damage. As a result, the usage of suitable materials and optimized fabrication techniques are required to achieve better control over the characteristics and functionality of the grafts. In particular, in the case of electrospun vascular grafts, the compliance can be adjusted throughout a broad range of values by adjusting the electrospinning parameters such as material selection, fiber orientation, porosity, and wall thickness. In this study, the electrospun vascular grafts consisting of pure PCL, PLA, and their blends were produced by using two different rotation speeds to achieve the oriented and non-oriented scaffolds. The impact of polymer type and fiber orientation on the compliance properties was evaluated. The results revealed that both material selection and fiber alignment have a significant effect on the compliance levels. PCL100_R grafts had the highest compliance value whereas the PCLPLA50_O scaffold had the lowest

    A PRELIMINARY STUDY EXAMINING THE BURST STRENGTH OF VASCULAR TUBULAR SCAFFOLDS

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    In this study, neat PCL, neat PLA and PLA/PCL (50/50) based tubular surfaces are produced by electrospinning to simulate the native blood vessel structure and to investigate the effects of both graft material and fiber orientation on burst strength. The burst pressure values of these vascular graft structures that designed with both randomly oriented fibers and oriented fibers, measured by a custom- burst pressure tester, and the results are compared. The results show that fiber orientation have a great influence on burst pressure, regardless of the type of biomaterial. It is determined that grafts with oriented fibers have at least twice the burst strength than those with random fibers. The findings indicate that changing the graft material has also an effect on burst strength. When the results are analyzed by polymer type, although the PLA100_O sample has the highest burst strength among all oriented fiber sample groups, it is better to determine the vascular graft candidate by taking into account radial elasticity

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

    International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

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    The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    Effects of dietary dried baker's yeast on the performance, egg traits and blood parameters in laying quails

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    This study was conducted to investigate the effects of dietary dried baker's yeast on laying performance, egg traits and some blood parameters of quails. In the experiment a total of 342 Japanese quails (Coturnix coturnix japonica) aged ten weeks were equally divided into six groups of 57 (three replicates of 19 quails each). Six levels (0, 4, 8, 12, 16 and 20%) of dried baker's yeast were included in isonitrogenous and isocaloric diets. The experimental period lasted 14 weeks. At the end of the experiment, there were no significant differences among the groups in body weight, feed intake, protein intake, egg production, feed efficiency, egg yolk index and egg haugh unit. Blood serum levels of total protein, triglyceride and cholesterol were not affected by dietary dried baker's yeast. Diets containing 4 and 8% of dried baker's yeast increased the egg weight significantly (p < 0.01). The inclusion of dried baker's yeast at the level of 20% to the diets reduced egg shell thickness and egg albumen height. It is concluded that dried baker's yeast can be used up to 16% in the diets of laying quails without adverse effects on the measured parameters

    The Factors That Affect Milk-to-Serum Ratio for Iron During Early Lactation

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    To determine the factors that affect milk iron content at the second week of lactation and whether the supplementation lactating mother with iron might increase breast milk iron content between 2 weeks and 4 months postpartum. Healthy mothers were enrolled 10 to 20 days postpartum, if their babies were term, normal gestational age, and exclusive breastfed. Maternal blood samples for hemoglobin (Hb), iron, iron binding capacity, serum ferritin, and breast milk samples for iron and zinc were taken and mothers were randomized into iron Supplemented Mid placebo groups. At the end of the fourth month, blood and milk samples were taken again. Forty-seven healthy mothers were included into file Study. Milk iron content was lower; however, milk-to-serum iron ratio was higher in cases with low maternal iron reserves than cases with adequate iron reserves. Mothers with low Hb level ((sic) 12g.dL) had higher milk zinc content and lower milk iron/zinc content than mothers with normal Hb value. Iron supplementation to lactating nonanemic mothers did not change milk iron content and the decline in milk iron content and milk-to-serum iron ratio. Milk iron content and milk-to-serum iron ratio of iron could be regulated by active transport in cooperation with maternal iron status
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