首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   236篇
  免费   8篇
  国内免费   1篇
  245篇
  2023年   2篇
  2022年   5篇
  2021年   5篇
  2020年   9篇
  2019年   3篇
  2018年   4篇
  2017年   3篇
  2016年   6篇
  2015年   9篇
  2014年   11篇
  2013年   12篇
  2012年   17篇
  2011年   14篇
  2010年   13篇
  2009年   9篇
  2008年   6篇
  2007年   6篇
  2006年   7篇
  2005年   7篇
  2004年   6篇
  2003年   2篇
  2002年   6篇
  2001年   3篇
  2000年   3篇
  1999年   3篇
  1998年   4篇
  1992年   4篇
  1991年   3篇
  1988年   2篇
  1985年   3篇
  1983年   3篇
  1982年   1篇
  1981年   2篇
  1980年   5篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1976年   2篇
  1975年   4篇
  1974年   7篇
  1973年   1篇
  1972年   1篇
  1971年   5篇
  1970年   1篇
  1969年   3篇
  1968年   3篇
  1967年   2篇
  1966年   1篇
  1964年   3篇
  1961年   1篇
排序方式: 共有245条查询结果,搜索用时 15 毫秒
31.
Balakrishna  Sivadi 《Cluster computing》2022,25(2):1441-1457
Cluster Computing - With the prevailing advancements in sensor technologies such as the Internet of Things (IoTs), cyber–physical-systems (CPSs), wireless sensor networks (WSNs), and many...  相似文献   
32.
Beta-lactam- and in particular carbapenem-resistant Enterobacteriaceae represent a major public health threat. Despite strong variation of resistance across geographical settings, there is limited understanding of the underlying drivers. To assess these drivers, we developed a transmission model of cephalosporin- and carbapenem-resistant Klebsiella pneumoniae. The model is parameterized using antibiotic consumption and demographic data from eleven European countries and fitted to the resistance rates for Klebsiella pneumoniae for these settings. The impact of potential drivers of resistance is then assessed in counterfactual analyses. Based on reported consumption data, the model could simultaneously fit the prevalence of extended-spectrum beta-lactamase-producing and carbapenem-resistant Klebsiella pneumoniae (ESBL and CRK) across eleven European countries over eleven years. The fit could explain the large between-country variability of resistance in terms of consumption patterns and fitted differences in hospital transmission rates. Based on this fit, a counterfactual analysis found that reducing nosocomial transmission and antibiotic consumption in the hospital had the strongest impact on ESBL and CRK prevalence. Antibiotic consumption in the community also affected ESBL prevalence but its relative impact was weaker than inpatient consumption. Finally, we used the model to estimate a moderate fitness cost of CRK and ESBL at the population level. This work highlights the disproportionate role of antibiotic consumption in the hospital and of nosocomial transmission for resistance in gram-negative bacteria at a European level. This indicates that infection control and antibiotic stewardship measures should play a major role in limiting resistance even at the national or regional level.  相似文献   
33.
Urinary catheterization is a routine procedure in an intensive care unit (ICU) for monitoring the urine output of critically ill patients. The catheters which are most often used to help with urinary incontinence and retention also face problems like blockage, leakage and infection. These problems are due to proteins that adhere to the catheter surface and quickly build up on each other forming a protein layer. As the layers build up they can crystallize, providing the major source of blockage and leakage. Current strategies to avoid these problems include coating a catheter with silver alloy to reduce bacteria on the catheter surface. However, silver alloy coatings can lead to increased silver resistance for bacteria. Since silver is already used as an antibacterial agent in many places in a hospital, it is even more possible that resistance can develop. An alternative solution is presented involving coating latex, a common urinary catheter material with a micro layer (5-100 microns) of polyethylene glycol. This hydrogel is applied using an interfacial photopolymerization process with ethyl eosin as the photoinitiator. A 25 ppm concentration of ethyl eosin provided the strongest gel to surface adhesion and significantly lowered protein adhesion when compared to an uncoated latex substrate.  相似文献   
34.
Applied Biochemistry and Microbiology - Anticancer activity of 9,10-anthraquinone isolated from soil-derived (Doddabetta forest, Nilgiris, Tamil Nadu, India) filamentous bacterium Streptomyces sp....  相似文献   
35.
Design of potential drug-like candidates for cancer is of interest in recent years. We used 60 compounds which are known to have the potential to down regulate Nuclear Factor kappaB (NFκB) for this study. The compounds were assessed for Lipinski's RO5 and ADMET properties. Allixin, anethole, capsaicin, linearol and syringic acid satisfied both Lipinski's RO5 and ADMET properties. These compounds showed strong molecular interaction with receptor GPCR55 indicating they have ability to block GPCR55. Thus, their role in anticellular proliferation and induction of apoptosis is implied.  相似文献   
36.
Membrane-bound enzymes play a vital role in neuronal function through maintenance of membrane potential and impulse propagation. We have evaluated the harmful effects of chronic cigarette smoking on membrane-bound ATPases and the protective effect of Bacoside A in rat brain. Adult male albino rats were exposed to cigarette smoke for a period of 12 weeks and simultaneously administered with Bacoside A (the active principle isolated from Bacopa monniera) at a dosage of 10 mg/kg b.w/day, p.o. The levels of lipid peroxides as marker for evaluating the extent of membrane damage, the activities of Na+/K+-ATPase, Ca2+-ATPase and Mg2+-ATPase, and associated cations sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) were investigated in the brain. Neuronal membrane damage was evident from the elevated levels of lipid peroxides and decreased activities of membrane-bound enzymes. Disturbances in the electrolyte balance with accumulation of Na+ and Ca2+ and depletion of K+ and Mg2+ were also observed. Administration of Bacoside A inhibited lipid peroxidation, improved the activities of ATPases, and maintained the ionic equilibrium. The results of our study indicate that Bacoside A protects the brain from cigarette smoking induced membrane damage.  相似文献   
37.
A series of fused and functionalized pyridine derivatives were designed, synthesized and tested for their potential antitubercular properties. All these novel compounds were prepared by using multistep methods involving the construction of pyridine ring as a key synthetic step. Some of these compounds were found to be interesting when tested for their antitubercular properties in vitro and one of them appeared as an attractive and potential antitubercular agent.  相似文献   
38.
—Studies were made of the effects of fluphenazine, chlorpromazine and triflupromazine on tissue concentration, liver synthesis of ascorbic acid and its distribution in different areas of the brain. All the three drugs were found to increase liver concentration and synthesis of the vitamin at 24 hr after administration of a single oral dose of the vitamin, but only fluphenazine was found to increase its concentration in the adrenals and brain; the increase in the latter case was found to vary in different regions of the brain, the olfactory lobes, hypothalamus and residual brain showing maximum increases, andthe basal ganglia, visual cortex and remaining dorsal cortex showing minimum increases. The effects were found to be reversed 72 hr after drug treatment.  相似文献   
39.
Administration of camptothecin (7,14 or 28 mg per 100 g body wt.) to rats intraperitoneally, induced single strand breaks in hepatic DNA. Fragmentation of liver DNA on alkaline sucrose gradients was noted within 5 minutes and reached a maximum by 30 to 60 minutes after the administration of the drug. By about 4 hours, the DNA damage was almost completely repaired. However, using neutral sucrose gradients, significant fragmentation of DNA could not be seen. The rapid repair of the liver DNA in vivo induced by camptothecin, a cancer chemotherapeutic agent, is interesting in view of the long delay in the repair of the DNA damage induced by several chemical carcinogens in an intact animal (9,10).  相似文献   
40.
The in vivo chain elongation of rat liver DNA following partial hepatectomy was studied using alkaline sucrose gradients. DNA made in 5 min was less than 4 × 107 daltons and that made in 30 min was heterodisperse and by 4 hr 75% of the DNA became larger than 1 × 109 daltons. Administration of 1-β-D-arabinofuranosyl cytosine (ara-C) 5 min after thymidine-3H injection inhibited the chain elongation, whereas if given 30 minutes after thymidine-3H pulse did not inhibit the chain elongation. Thus the in vivo chain elongation of rat liver DNA consists of at least two steps 1) a step sensitive to ara-C involving nucleotides addition and 2) the other insensitive to ara-C and probably involving ligation of polynucleotide chains.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号