407 research outputs found

    Influence of misonidazole on the incidence of radiation-induced intestinal tumours in mice.

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    C57BL mice were given local irradiation to 2 cm2 of the lower abdomen in the dose range 16--24 Gy. There were some early deaths, but mice dying between 50--240 days predominantly developed invasive adenocarcinomas of the intestine. When the radiosensitizer misonidazole was given in a single dose shortly before irradiation the proportion of mice developing tumours was higher, but the difference was not statistically significant. However, there was a significant increase in the incidence of multiple tumours, largely attributable to tumours arising in the rectum

    Computational fluid dynamics study of crec riser simulator: mixing patterns

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    The CREC Riser Simulator Reactor is a novel mini-fluidized reactor. This novel device was invented by de Lasa 1. The applications of this unit has shown to be of great value to establish catalyst performance and kinetic models for a diversity of gas phase catalytic reactions. This has been the case, given that the CREC Riser Simulator is excellent with respect to particle and fluid mixing2. This study establishes using CFD (Computational Fluid Dynamics), the CREC Riser Simulator mixing flow patterns. CFD simulations were developed using the COMSOL Multiphysics® module. Fig.1a reports the geometric characteristics of the CREC Riser Simulator including the impeller, the basket containing the catalyst and the external baffles.The proposed CFD model was validated using experimental data obtained in a basket as shown in Fig.1a. For instance, for an impeller speed of 4000 rpm, the outer annulus experimental gas velocity2 was ~0.9 m/s and the simulated CFD gas velocity2 was ~1.3 m/s. Please click Additional Files below to see the full abstract

    Electrodeposition of Copper from a Choline Chloride based Ionic Liquid

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    采用恒电流和恒电位方法,基于含有氯化铜溶液的乙二醇-氯化胆碱或硫脲-氯化胆碱离子液体,室温下在钢阴极上进行了铜的电沉积. 利用扫描电子显微镜和X-射线衍射技术研究了各种实验条件对电沉积的影响以及沉积层的形貌. 结果表明,室温下施加不超过-0.45 V的沉积电位和不超过-4.0 A·m-2的沉积电流密度,可以同时从氯化胆碱基乙二醇和硫脲离子液体中沉积得到非常光滑、有光泽、致密且具有良好结合力、色泽鲜艳的铜金属涂层. 铜的电沉积阴极电流效率约为97%.The electrodeposition of copper from a solution containing copper chloride in either an ethylene glycol (EG)-choline chloride based or a urea-choline chloride based ionic liquid has been carried out onto a steel cathode by constant current and constant potential methods at room temperature. The influences of various experimental conditions on electrodeposition and the morphology of the deposited layers have been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is shown that very smooth, shiny and dense with good adherence and bright metallic coloured copper coatings can be obtained from both EG and urea based ionic liquids at the applied deposition potentials up to -0.45 V and applied deposition current densities up to -4.0 A·m-2 at room temperature. The cathodic current efficiency for the deposition of copper is about 97%.The authors gratefully acknowledge the Ministry of Science and Technology, the People's Republic of Bangladesh for financial support of this work(Grand Reference No. MOSICT/PRC-24/2009-2010/BS-52/172).  The authors gratefully acknowledge the Ministry of Science and Technology, the People's Republic of Bangladesh for financial support of this work(Grand Reference No. MOSICT/PRC-24/2009-2010/BS-52/172).作者联系地址:拉杰沙希大学应用化学和化学工程系,拉杰沙希-6205, 孟加拉国Author's Address: Department of Applied Chemistry and Chemical Engineering, University of Rajshahi, Rajshahi-6205, Bangladesh通讯作者E-mail:[email protected]

    Optimizing Medium Components to Enhance High Cell Mass Production of Biotherapeutic Strain Lactobacillus reuteri DSM 20016T by Statistical Method

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    798-803Probiotics referred to a group of living microorganisms which highly influence the human health. A number of studies have highlighted on the bio-therapeutic potential of Lactobacillus reuteri strains, especially in treating eradication of Helicobacter pylori. Therefore, in present investigation, statistical methods were applied to optimize medium composition for high cell mass production of L. reuteri strain DSM 20016T. Most influencing medium components were screened by using Plackett-Burman and optimized using Box-Bhenken experimental design. The concentration of lactose, yeast extract and phosphate in cultivation medium has shown significant effect on the cell mass production. The highest cell mass obtained after 48h incubation was 3.96 ± 0.02 gL−1 in RSM-optimized medium compared to 1.76 ± 0.17 gL−1 in un-optimized medium

    Symptoms and signs in individuals with serology positive for celiac disease but normal mucosa

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    <p>Abstract</p> <p>Background</p> <p>Antibody serology is an important tool in the investigation of celiac disease (CD), but does not always correlate with mucosal appearance in the small intestine. Patients with positive CD serology but normal mucosa (Marsh 0) are at increased risk of future CD. In this study we describe a model for identifying and characterizing individuals with normal mucosa but positive CD serology. Such individuals are sometimes referred to as having latent CD.</p> <p>Methods</p> <p>The records of ten Swedish pathology departments were used to identify individuals with biopsies indicating normal duodenal/jejunal mucosa. Using the national personal identification number, these data were linked with CD serology data (antigliadin, antiendomysial and tissue transglutaminase antibodies); and we thereby identified 3,736 individuals with normal mucosa but positive CD serology. Two independent reviewers then manually reviewed their biopsy reports to estimate comorbidity. We also randomly selected 112 individuals for validation through patient chart review.</p> <p>Results</p> <p>The majority of the 3,736 individuals were females (62%). Children (0–15 years) made up 21.4%. The median number of biopsy specimen was 3. Our review of biopsy reports found that other gastrointestinal comorbidity was rare (inflammatory bowel disease: 0.4%; helicobacter pylori infection: 0.2%). Some 22% individuals selected for patient chart review had a relative with CD. The most common symptoms among these individuals were diarrhea (46%) and abdominal pain (45%), while 26% had anemia. Although 27% of the individuals selected for validation had been informed about gluten-free diet, only 13% were adhering to a gluten-free diet at the end of follow-up.</p> <p>Conclusion</p> <p>Individuals with positive CD serology but normal mucosa often have CD-like symptoms and a family history of CD.</p

    Cardiovascular safety of celecoxib in acute myocardial infarction patients: a nested case-control study

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    The objective was to measure the impact of exposure to coxibs and non-steroidal antiinflammatory drugs (NSAID) on morbidity and mortality in older patients with acute myocardial infarction (AMI). A nested case-control study was carried out using an exhaustive population-based cohort of patients aged 66 years and older living in Quebec (Canada) who survived a hospitalization for AMI (ICD-9 410) between 1999 and 2002. The main variables were all-cause and cardiovascular (CV) death, subsequent hospital admission for AMI, and a composite end-point including recurrent AMI or CV death. Conditional logistic regressions were used to estimate the risk of mortality and morbidity. A total of 19,823 patients aged 66 years and older survived hospitalization for AMI in the province of Quebec between 1999 and 2002. After controlling for covariables, the risk of subsequent AMI and the risk of composite end-point were increased by the use of rofecoxib. The risk of subsequent AMI was particularly high for new rofecoxib users (HR 2.47, 95% CI 1.57–3.89). No increased risk was observed for celecoxib users. No increased risk of CV death was observed for patients exposed to coxibs or NSAIDs. Patients newly exposed to NSAIDs were at an increased risk of death (HR 2.22, 95% CI 1.30–3.77) and of composite end-point (HR 2.28, 95% CI 1.35–3.84). Users of rofecoxib and NSAIDs, but not celecoxib, were at an increased risk of recurrent AMI and of composite end-point. Surprisingly, no increased risk of CV death was observed. Further studies are needed to better understand these apparently contradictory results

    Recent evolution in thermochemical transformation of municipal solid wastes to alternate fuels

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    The management of solid waste poses a worldwide obstacle in the pursuit of a sustainable society. This issue has intensified with the increase in waste production caused by rapid population expansion, industrialization, and urbanization. The continuously growing volume of municipal solid waste, particularly the substantial volume of organic waste, along with improper disposal practices, results in the release of greenhouse gases and other harmful airborne substances which simultaneously causes health risks and socioeconomic concerns. This article examines various waste-to-energy (energy production in the form of heat and electricity) concepts as well as waste-to-materials (various value-added materials including biofuel, biochemical, char, bio-oil, soil fertilizer, etc.) methods of converting municipal solid waste into environmentally friendly fuels, which appear to be economically feasible and attractive. It starts with a thorough analysis of the characteristics of municipal solid waste followed by the generation procedure. The study provides an overview of different thermochemical conversion methods including incineration, pyrolysis, co-pyrolysis, liquefaction, hydrothermal carbonization, gasification, combustion for transformation of municipal solid waste, and their recent advancement. The review comprehensively discussed the pros and cons of each method highlighting their strength, weakness, opportunities, and threats to transforming MSW. The current state of municipal solid waste management, including effective dumping and deviation, is comprehensively assessed, along with the prospects and challenges involved. Energy justice concepts and fuzzy logic tool is used to address the selection criteria for choosing the best waste treatment techniques. Moreover, several recommendations are offered to enhance the existing solid waste management system. This review could assist scholars, researchers, authorities, and stakeholders in making informed decisions regarding MSW management
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