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排序方式: 共有436条查询结果,搜索用时 46 毫秒
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Zhen Luo Zhuoqing Li Zhe Xie Inna M. Sokolova Lan Song Willie J. G. M. Peijnenburg Menghong Hu Youji Wang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(36)
Titanium dioxide nanoparticles (nano‐TiO2) are widely used in consumer products, raising environmental and health concerns. An overview of the toxic effects of nano‐TiO2 on human and environmental health is provided. A meta‐analysis is conducted to analyze the toxicity of nano‐TiO2 to the liver, circulatory system, and DNA in humans. To assess the environmental impacts of nano‐TiO2, aquatic environments that receive high nano‐TiO2 inputs are focused on, and the toxicity of nano‐TiO2 to aquatic organisms is discussed with regard to the present and predicted environmental concentrations. Genotoxicity, damage to membranes, inflammation and oxidative stress emerge as the main mechanisms of nano‐TiO2 toxicity. Furthermore, nano‐TiO2 can bind with free radicals and signal molecules, and interfere with the biochemical reactions on plasmalemma. At the higher organizational level, nano‐TiO2 toxicity is manifested as the negative effects on fitness‐related organismal traits including feeding, reproduction and immunity in aquatic organisms. Bibliometric analysis reveals two major research hot spots including the molecular mechanisms of toxicity of nano‐TiO2 and the combined effects of nano‐TiO2 and other environmental factors such as light and pH. The possible measures to reduce the harmful effects of nano‐TiO2 on humans and non‐target organisms has emerged as an underexplored topic requiring further investigation. 相似文献
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为实现国产自主可控,基于国产CPU 和麒麟操作系统,采用Qt 元语言(qt meta language,QML)和图形
处理器(graphics processing unit,GPU)编程的模式设计一种跨平台的实时显示软件。详细阐述基于QML 的软件架构
设计,并对软件设计中的QML、C++及GPU 的通信模式、QML 下CPU+GPU 编程实时显示性能优化方法以及QML
显示控件设计等关键技术进行说明,验证其应用。结果证明:该模型具有可靠、稳定、高效和跨平台等特点,满足
实时显示应用要求。 相似文献
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This paper provides meta‐analyses of the published findings relating the respiratory health of occupants of schools with visible dampness, water damage, visible mold, and/or mold odor. Random effects models were used to develop central estimates and confidence limits for the associations of respiratory health effects with school dampness and mold. Eleven studies, all with cross‐sectional designs, were included in the meta‐analyses; however, analyses for some health outcomes were based on as few as four studies. Analyses were performed using data from adults and children combined, using only data from children, and using data from adults and children after excluding two studies. The central estimates of odds ratios from the meta‐analyses were consistently above unity. The evidence of adverse health effects was strongest for cough and wheeze, which had confidence limits excluding unity in some or all analyses. The odds ratios of 1.32 for cough and 1.68 for wheeze suggest moderate increases in health risk. Studies not included in the meta‐analyses provide additional evidence that dampness and mold in schools are associated with adverse health outcomes. These meta‐analyses and the published literature not included in the meta‐analyses suggest that dampness and mold in schools are associated with adverse respiratory health effects. 相似文献
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Palangala S. Ravindra 《Information Systems Management》2013,30(1):74-75
More than just a regulatory body, the data administration group is responsible for planning and promoting the use of information resources. By managing the corporate data base effectively, data administration provides benefits to everyone who depends on the use of accurate information. 相似文献
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A meta‐analysis of sodium profiling techniques and the impact on intradialytic hypotension 下载免费PDF全文
Nina Dunne 《Hemodialysis international. International Symposium on Home Hemodialysis》2017,21(3):312-322
Introduction Hemodialysis has improved in recent years, however, despite such improvements, intra‐dialytic hypotensive episodes still persist which can lead to a reduction in the overall effectiveness of the treatment. Profiling sodium levels during dialysis can improve vascular refilling and therefore may prevent hypotensive events. A number of profiling methods exist and this meta‐analysis set out to examine the effectiveness of these methods. Methods To assess the effectiveness of hemodialysis sodium profiling techniques. A review and meta‐analysis analytical framework was used. A search was conducted using Medline, Embase and CINAHL, Scopus and Web of Knowledge between 1946 and 2014 of published English‐language peer reviewed randomized control studies. In total 10 articles were retrieved and included in the review. All data was abstracted with a standardized data collection form. Stata 11.2 (Stata Corp) was used to analyse the data. Actual numbers of hypotensive events were pooled between studies. Analysis of subgroups was performed on sodium profile type. The data were further investigated using meta‐regression. Publication bias was also tested. Findings Stepwise profiling was shown to be statistically significantly effective in reducing intradialytic episodes. Results demonstrated that linear sodium profiling was not effective in reducing hypotensive events during dialysis. Discussion This review has shown that using stepwise profiling is more effective at reducing intra‐dialytic symptoms than other profiling methods. There was no evidence that linear profiling method was any more effective than conventional dialysis and in fact the results showed the reverse. 相似文献
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Saeed Gholizadeh Amir Masoud Shahrezaei 《The Structural Design of Tall and Special Buildings》2015,24(1):1-18
Layout optimization of steel frames with steel plate walls (SPWs) using a meta‐heuristic search algorithm is the main aim of the present study. SPWs are lateral load‐resisting systems, especially against earthquake excitation. These systems offer significant advantages in terms of cost, performance and ease of design compared with other systems. In this study, orthotropic membrane model is used to model the behaviour of steel plate shear walls. The newly developed bat algorithm, which is based on the echolocation behaviour of bats, is employed as the present study optimizer. Design variables of the optimization problem consist of the cross sections of beams and columns of the frame, the web plate thicknesses of SPWs and the placement of SPW in the frame. The bat algorithm performs suitable selection of sections from the AISC wide‐flange (W) shapes list. Strength constraints of the American Institute of Steel Construction Load and Resistance Factor Design and displacement constraints are checked during the optimization process. The results reveal the effectiveness of the proposed method for optimization of steel frames with SPWs. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Amlan K Patra 《Journal of the science of food and agriculture》2010,90(15):2700-2708
BACKGROUND: A meta‐analysis study was conducted to investigate the changes in rumen fermentation characteristics when methane inhibition by phytochemicals is employed. The whole database containing 185 treatment means from 36 published studies was divided into four subsets according to the major phytochemicals used in the studies, i.e. saponins, tannins, essential oils (EO) and organosulfur compounds (OS). RESULTS: Changes in protozoal numbers showed linear relationships with changes in methane production by saponins (R2 = 0.48), tannins (R2 = 0.30) and EO (R2 = 0.20) but not OS. Concentrations of total volatile fatty acids (VFA) and acetate did not show any relationship (P > 0.1) with changes in methane due to saponins. However, propionate production increased linearly with increasing inhibition of methane (R2 = 0.31), which resulted in a linear (R2 = 0.26) decrease in acetate/propionate ratio (A/P) with decreasing methane production. Concentrations of total VFA, acetate and propionate did not change with changes in methane production by tannins. However, A/P showed a significant linear relationship (R2 = 0.27) with decreasing methane formation. Concentrations of total VFA (R2 = 0.44) and propionate (R2 = 0.15) changed linearly and positively with changes in methane production by EO. However, acetate production (R2 = 0.22) and A/P (R2 = 0.17) increased linearly with increasing inhibition of methane by EO. Changes in concentrations of total VFA (R2 = 0.60) and acetate (R2 = 0.35) decreased linearly while those of propionate increased linearly (R2 = 0.23) with increasing inhibition of methane by OS. Consequently, A/P decreased linearly (R2 = 0.30) with decreasing methane production by OS. Digestibilities of organic matter (OM) and neutral detergent fibre were not affected by inhibition of methane production by saponins, EO and OS, but digestibility of OM decreased with decreasing methane production by tannins. CONCLUSION: The inhibition of methane production by phytochemicals results in changes in rumen fermentation that differ depending on the types of phytochemicals. Copyright © 2010 Society of Chemical Industry 相似文献