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   2374735篇
  免费   169460篇
  国内免费   4288篇
耳鼻咽喉   33495篇
儿科学   74275篇
妇产科学   67595篇
基础医学   342438篇
口腔科学   69153篇
临床医学   212168篇
内科学   460043篇
皮肤病学   52688篇
神经病学   189817篇
特种医学   90987篇
外国民族医学   676篇
外科学   353507篇
综合类   52446篇
现状与发展   8篇
一般理论   960篇
预防医学   181427篇
眼科学   55207篇
药学   177123篇
  11篇
中国医学   4683篇
肿瘤学   129776篇
  2018年   23088篇
  2016年   19894篇
  2015年   22746篇
  2014年   31627篇
  2013年   48497篇
  2012年   64621篇
  2011年   68664篇
  2010年   40345篇
  2009年   38901篇
  2008年   65468篇
  2007年   70671篇
  2006年   70905篇
  2005年   68976篇
  2004年   66766篇
  2003年   64232篇
  2002年   62811篇
  2001年   107402篇
  2000年   109872篇
  1999年   93019篇
  1998年   25733篇
  1997年   23398篇
  1996年   23226篇
  1995年   21873篇
  1994年   20505篇
  1992年   73106篇
  1991年   71435篇
  1990年   69670篇
  1989年   67954篇
  1988年   63143篇
  1987年   62061篇
  1986年   59528篇
  1985年   56222篇
  1984年   42547篇
  1983年   36598篇
  1982年   21879篇
  1981年   19894篇
  1979年   40749篇
  1978年   29514篇
  1977年   25114篇
  1976年   23142篇
  1975年   25660篇
  1974年   30779篇
  1973年   30127篇
  1972年   28804篇
  1971年   26864篇
  1970年   25413篇
  1969年   24320篇
  1968年   22715篇
  1967年   20444篇
  1966年   19222篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
Here we report how the different types of regional muscle involvement, i.e. bulbar, ocular or generalized, in patients with myasthenia gravis (MG) influence the mental aspects of quality of life. Clinical examination according to Osserman was performed in 48 MG patients (45 women, three men; mean age 54, SD 12 years). Each patient was at the time for clinical evaluation asked to fill out the disease-specific Myasthenia Gravis Questionnaire (MGQ) and the Short-Form 36-item questionnaire for health survey (SF-36) as patient-oriented tools. We related the regional domains (generalized domain, bulbar domain and ocular domain) of the MGQ and the clinical findings, respectively, with mental quality of life as assessed by SF-36. Bulbar and generalized involvement results in impairment of mental aspects of quality of life, whereas ocular involvement does not.  相似文献   
65.
To determine if impaired energy metabolism might contribute to some aspects of Alzheimer disease (AD), including the vulnerability of the CA1 region of the hippocampal formation and the altered cytoskeleton evident in neurofibrillary tangles, we examined the effects of metabolic poisons on neuronal damage and cytoskeletal disruption in the hippocampal formation. Intrahippocampal injection of 3-nitropropionic acid (3-NP) and malonic acid resulted in neuronal death, particularly in CA1. Cytoskeletal disruption included loss of dendritic MAP2, but sparing of axonal τ. MK-801 (a noncompetitive NMDA receptor antagonist) did not atenuate the lesions produced by intrahippocampal injection of malonate. MK-801, however, was effective against intrastriatal malonate. Acute systemic 3-NP resulted in neuronal damage and cytoskeletal disruption in the CA1 region of the hippocampal formation, including an extensive loss of MAP2 immuno-reactivity, but sparing of τ. The neuronal loss in CA1 was delayed as compared to striatum. Chronic intraventricular infusion of 3-NP produced a different pattern of neuronal damage. Loss of τ-1 immuno-reactivity was observed in CA3 and CA1 s. oriens, whereas MAP2 immunostaining was preserved. These results demonstrate that chronic and acute administration of metabolic inhibitors produce distinct patterns of neuronal damage and cytoskeletal disruption. The results further suggest a differential involvement of the NMDA receptor in malonate-induced neuronal damage in striatum as compared to the hippocampus. The pattern of neuronal damage and cytoskeletal disruption observed following acute metabolic impairment resembled some aspects of neurofibrillary pathology in AD, but did not result in τ hyperphosphorylation.  相似文献   
66.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease.  相似文献   
67.
68.
Setting goals to maintain hope.   总被引:3,自引:0,他引:3  
  相似文献   
69.
70.
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