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   7105篇
  免费   460篇
各国政治   333篇
工人农民   221篇
世界政治   462篇
外交国际关系   231篇
法律   5003篇
中国政治   34篇
政治理论   1246篇
综合类   35篇
  2020年   157篇
  2019年   166篇
  2018年   176篇
  2017年   207篇
  2016年   210篇
  2015年   196篇
  2014年   179篇
  2013年   735篇
  2012年   153篇
  2011年   167篇
  2010年   205篇
  2009年   222篇
  2008年   162篇
  2007年   157篇
  2006年   166篇
  2005年   158篇
  2004年   176篇
  2003年   156篇
  2002年   137篇
  2001年   309篇
  2000年   250篇
  1999年   225篇
  1998年   97篇
  1997年   64篇
  1996年   69篇
  1995年   79篇
  1994年   86篇
  1993年   87篇
  1992年   151篇
  1991年   156篇
  1990年   145篇
  1989年   155篇
  1988年   122篇
  1987年   137篇
  1986年   124篇
  1985年   132篇
  1984年   101篇
  1983年   116篇
  1982年   82篇
  1981年   78篇
  1980年   55篇
  1979年   108篇
  1978年   69篇
  1977年   58篇
  1976年   50篇
  1975年   47篇
  1974年   55篇
  1973年   55篇
  1972年   44篇
  1968年   40篇
排序方式: 共有7565条查询结果,搜索用时 0 毫秒
321.
Arterial fibromuscular dysplasia (FMD) represents a collection of noninflammatory and nonatherosclerotic vascular diseases with a poorly understood etiology. Classically occurring in renal and cerebral arteries, this entity has also been reported in coronary, carotid, and other medium and small arteries. One case occurring in the pulmonary vasculature has been reported. Fatal hemothorax and lung hemorrhage have multiple causes, including other vascular malformations and connective tissue disorders; however, cases of pulmonary FMD are exceedingly rare. We report what appears to be the second such association, occurring in a 69-year-old man. The patient presented with a 3-week history of increasing dyspnea, fatigue, and productive cough; 3 days of increasing back and chest pain; and syncope. Chest radiograph showed a "white-out" of the left lung. The patient died shortly after admission from a fulminant respiratory disease of undetermined etiology. At autopsy he was found to have a massive left hemothorax resulting from an unsuspected pulmonary arterial fibromuscular dysplasia.  相似文献   
322.
Olanzapine is an antipsychotic drug that has been on the market since 1996. Olanzapine-related deaths are very rare; the literature reports only one. However, in a recent 5-month period one medical examiner's office found two such cases that are reported in this paper. One is a suicide and the other is not. The toxicologic and anatomic findings for each are described. Blood olanzapine concentrations ranged from 0.237 microg/ml for one to 0.675 microg/ml for the other. Gastric content concentrations also exhibited a wide range, varying from 0.197 microg/ml to 17.400 microg/ml for the other. Distribution studies of the liver, kidney, and brain produced nondetectable concentrations for the drug. There were no consistent pathologic anatomic findings for cause of death except for moderate coronary atherosclerosis in the nonsuicide case. Both deaths were attributed to olanzapine toxicity.  相似文献   
323.
The authors report a fatal case of a Persian leopard (Panthera pardus) attack in an animal sanctuary in Oklahoma. The victim was a 53-year-old Costa Rican woman who was attempting to feed the animal when she was attacked and killed. Autopsy, radiography, fingerprint analysis, microbiologic cultures, and dental impressions were used to evaluate the case. These simple techniques can be applied to similar cases involving wild and domestic animal attacks.  相似文献   
324.
325.
326.
327.
OBJECTIVE: To describe the death of a toddler after a therapeutic dose of dextromethorphan and its investigation. STUDY DESIGN: Case report, cytochrome P450 phenotype and genotype determination in the victim and post-mortem drug redistribution study performed in rats. RESULTS: A 20-month Asian male who received 3 mg of dextromethorphan once at 09:00 h and again at 22:00 h was found dead at 04:35 h. Post-mortem examination showed signs of early bronchopneumonia (bacterial cultures were negative); dextromethorphan and dextrorphan blood concentrations taken from the heart cavity were 500 ng/ml (1. 84 micromol/l) and 200 ng/ml (0.78 micromol/l), respectively. Despite the dextromethorphan level being almost 100-fold higher than expected after therapeutic doses, intentional or unintentional overdose was extremely unlikely; other potential causes were investigated. Post-mortem drug redistribution study performed in rats showed that dextromethorphan does not undergo extensive redistribution after death (6+/-5-fold increase) and could not explain the observed dextromethorphan level. The dextromethorphan/dextrorphan concentration ratio of 2.5 found in this toddler was compatible with a slow CYP2D6 metabolizer phenotype. However, the toddler exhibited a fast metabolizer genotype. Potential reasons for this discrepancy are discussed. CONCLUSION: CYP450 phenotypes derived from post-mortem blood levels should be interpreted with caution and preferably confirmed by a genotype analysis.  相似文献   
328.
329.
Pulmonary edema complicating heroin overdosage is a well recognized entity and regarded as the major mechanism contributing to death in heroin addicts. It's pathogenesis is unknown, several mechanisms are discussed: hypoxia-induced increase of pulmonary capillary permeability, depressed myocardial contractility, centrally induced respiratory depression, primary toxic effects on the alveolar capillaries and acute anaphylactic shock. The present study included opiate-related deaths (n=23) and a control group of sudden cardiovascular deaths (n=12) to verify the hypothesis, that defects of the alveolar capillary membranes and/or an acute anaphylactic reaction leads to pulmonary congestion, edema and hemorrhages. Lung specimens were obtained from these 35 autopsies of persons autopsied in the Institute of Forensic Medicine, University of Bonn, in 1997 and 1998. All specimens were examined with hematoxylin-eosin, prussian blue and investigated with immunohistological methods using primary antibodies against collagen IV, laminin and IgE. Defects of the basal laminae of the alveoli were found, demonstrated by laminin and collagen IV, and the number of IgE-positive cells was counted in both groups. There was an increased but not significant number of IgE-positive cells in the heroin-group and defects of the epithelial and endothelial basal laminae were found in both groups without significant differences.  相似文献   
330.
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