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   248篇
  免费   11篇
  国内免费   1篇
儿科学   15篇
妇产科学   4篇
基础医学   30篇
口腔科学   4篇
临床医学   23篇
内科学   45篇
皮肤病学   3篇
神经病学   10篇
特种医学   14篇
外科学   45篇
综合类   11篇
一般理论   1篇
预防医学   15篇
药学   18篇
中国医学   7篇
肿瘤学   15篇
  2024年   2篇
  2023年   1篇
  2022年   5篇
  2021年   9篇
  2020年   8篇
  2019年   7篇
  2018年   10篇
  2017年   7篇
  2016年   5篇
  2015年   15篇
  2014年   11篇
  2013年   7篇
  2012年   14篇
  2011年   14篇
  2010年   9篇
  2009年   7篇
  2008年   22篇
  2007年   19篇
  2006年   16篇
  2005年   9篇
  2004年   9篇
  2003年   10篇
  2002年   5篇
  2001年   3篇
  2000年   4篇
  1999年   6篇
  1998年   2篇
  1997年   2篇
  1991年   1篇
  1987年   1篇
  1986年   2篇
  1984年   4篇
  1983年   2篇
  1981年   3篇
  1980年   4篇
  1978年   1篇
  1972年   2篇
  1971年   1篇
  1970年   1篇
排序方式: 共有260条查询结果,搜索用时 218 毫秒
51.
52.
Despite the implementation of new antifungal drugs, invasive aspergillosis (IA) still remains a considerable challenge in pediatric oncology with a severe mortality. Prophylactic and therapeutic measurement have to be evaluated in these rare but poor prognostic patients. Therefore the entire group of patients at risk of developing IA has to be defined before cooperative prospective trials. In a retrospective analysis including all our patients with malignancies we looked for patients with proven/probable IA. Cases of the period from 2003 to 2008 were analyzed in detail.In the period between 2003 to 2008 24 of 755 patients were affected by proven/ probable IA. Compared to former studies incidence increased from 1.3%in 1980 to 3.4% in 2008. AML patients with or without allogeneic/haploidentical stem cell transplantation were at highest risk (24% and 25% respectively, in comparison to 1% in ALL-patients). Survival after 2 years was 50% for patients with AML and IA. In patients with high risk to develop IA the effect of intensified, intravenous antimycotic prophylaxis has to be proven prospectively in a cooperative and randomized setting.  相似文献   
53.
54.
Haplotype analysis of closely associated markers has proven to be a powerful tool in kinship analysis especially when X-chromosome short tandem repeats fail to resolve uncertainty in relationship analysis. Microsatellites located on the X chromosome show stronger linkage disequilibrium compared with autosomal microsatellites; hence, it is necessary to estimate the haplotype frequencies directly from population studies as linkage disequilibrium is population-specific. Here, we describe five markers residing in two clusters; cluster I harboring three STR markers DXS6801–DXS6809–DXS6789 and cluster II harboring two STR markers DXS7424–DXS101. A total of 302 male DNA samples of Pakistani descent were analyzed. Theoretically, 847 and 160 different combinations of haplotypes are possible in clusters I and II, but genotyping identified only 129 and 75 haplotypes, respectively. No evidence of linkage disequilibrium was detected, except for the pair (DXS6801–DXS6789), consistent with results obtained with the cluster I in a German population. Our results demonstrate that 83% haplotypes of cluster I and 65% haplotypes of cluster II show <1% frequency in the Pakistani population. This strongly suggests that haplotypes of these two clusters provide a powerful tool for kinship testing and relationship investigations. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. This study was supported in part by Higher Education Commission and Ministry of Science and Technology Islamabad, Pakistan.  相似文献   
55.
56.
57.
Four different methods are used to study the neutron slowing down and to evaluate the neutron resonance escape probability in an infinite homogeneous medium containing a heavy resonant nuclide [U238] and a light moderator nuclide [H]. Two statistical methods use the Monte Carlo simulation and two deterministic methods are based on the numerical solutions of the neutron slowing down equation and a corresponding adjoint equation with an appropriate adjoint source.This study has been done for several dilutions and for two neutron source energies (Es = 676.45 eV and Es = 2 MeV). The cut-off energy is placed at 2.77 eV.We have found that the direct numerical solution of the neutron slowing down equation does not agree with the other three methods. In order to eliminate this disagreement, we have taken account of some corrections concerning the hydrogen cross-section in the thermal region.  相似文献   
58.
59.
Dipeptidyl-peptidase-IV (DPP-IV) inhibitors are a new class of oral hypoglycaemic agents recently approved for the management of type 2 diabetes mellitus. Early data suggested that they had a positive impact on the cardiovascular system: treatment appeared to result in improvements in cardiac performance, blood pressure and lipid levels. However, recent clinical findings bring this into question. Our understanding of the physiological actions of these agents is complicated by the fact that DPP-IV has a wide range of substrates in addition to glucagon-like peptide 1. Indeed, DPP-IV inhibition alters concentrations of a wide variety of cytokines and neuropeptides. A deeper understanding of the physiological effects of these drugs as well as their true impact on cardiovascular risk is needed before consideration can be given to extending their use beyond the treatment of diabetes.  相似文献   
60.
BACKGROUND: In this study, we compared two wrist blood pressure-measuring devices, the Omron RX and the Nissei WS-310, against a mercury manometer. METHOD: A total of 152 subjects attending an out-patient hypertensive clinic were recruited from a randomized blood pressure survey, 87 patients (mean 44.4 +/- 14.5 years of age) being selected according to the Association for the Advancement of Medical Instrumentation/British Hypertension Society standards. Device validation was assessed through the use of sequential same-arm readings compared with readings taken using a mercury sphygmomanometer by the two trained observers. RESULTS: There were no differences between the observers and the monitors for diastolic readings (2.8 +/- 4.8 mmHg for the Omron and 4.2 +/- 6.4 mmHg for the Nissei) according to the Association for the Advancement of Medical Instrumentation standards. The largest standard deviations -- 8.3 mmHg for the Omron and 8.8 mmHg for the Nissei, respectively -- were seen for systolic readings recorded by the observers and the monitors. According to the British Hypertension Society standards, the Omron achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. The Nissei monitor achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. CONCLUSION: Patients found the wrist oscillometric devices that we tested to be comfortable and easy to use. These devices are appropriate for measuring diastolic blood pressure according to the standards, but the reliability of both devices decreased when measuring systolic blood pressure.  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