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   4707435篇
  免费   347935篇
  国内免费   11585篇
耳鼻咽喉   66436篇
儿科学   150480篇
妇产科学   127017篇
基础医学   654961篇
口腔科学   136967篇
临床医学   439382篇
内科学   904165篇
皮肤病学   103056篇
神经病学   392907篇
特种医学   182812篇
外国民族医学   1637篇
外科学   702071篇
综合类   108337篇
现状与发展   7篇
一般理论   2115篇
预防医学   384281篇
眼科学   110231篇
药学   347010篇
  15篇
中国医学   9051篇
肿瘤学   244017篇
  2018年   52110篇
  2017年   39823篇
  2016年   45176篇
  2015年   50999篇
  2014年   72033篇
  2013年   109542篇
  2012年   145860篇
  2011年   155485篇
  2010年   93138篇
  2009年   88513篇
  2008年   145350篇
  2007年   154476篇
  2006年   155835篇
  2005年   151278篇
  2004年   145753篇
  2003年   139878篇
  2002年   135703篇
  2001年   207674篇
  2000年   213684篇
  1999年   181391篇
  1998年   56062篇
  1997年   49475篇
  1996年   49019篇
  1995年   47562篇
  1994年   44177篇
  1993年   41414篇
  1992年   144649篇
  1991年   140445篇
  1990年   136056篇
  1989年   131229篇
  1988年   121416篇
  1987年   119691篇
  1986年   113285篇
  1985年   108958篇
  1984年   82480篇
  1983年   70564篇
  1982年   42875篇
  1981年   38760篇
  1979年   76328篇
  1978年   54499篇
  1977年   46148篇
  1976年   43309篇
  1975年   45891篇
  1974年   55645篇
  1973年   53226篇
  1972年   50087篇
  1971年   46614篇
  1970年   43427篇
  1969年   40931篇
  1968年   37759篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
81.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
82.
    
Ohne Zusammenfassung  相似文献   
83.
84.
85.
86.
OBJECTIVE: Spinal reflexes from hand to wrist muscles were investigated in writer's cramp. METHODS: Stimulus-triggered rectified EMG averages after ulnar nerve and cutaneous stimulation, in wrist flexors and extensors during tonic contraction, were compared in 18 controls and 19 patients. RESULTS: On the patient dystonic side, ulnar-induced EMG suppression was decreased in wrist extensors, and facilitation in wrist flexors modified dependent on the dystonic wrist posture during writing. No change was found on the patient non-dystonic side. Cutaneous stimulation increased wrist flexor EMG on both sides of the patients with normal wrist posture during writing, but had no effect in controls and patients with abnormal wrist posture. CONCLUSIONS: Comparison between cutaneous and mixed nerve stimuli suggests that spindle afferents from intrinsic hand muscles may mediate patients' ulnar-induced EMG modulations. Abnormal proprioceptive control was only observed on dystonic side, while bilateral unusual cutaneous control was found in patients. Changes in spinal transmission were partly related to the dystonic wrist posture, suggesting that systems involved in sensory processing can be differentially altered in writer's cramp. SIGNIFICANCE: Changes in spinal transmission, probably related to peripheral and/or cortical inputs, might either take part in primary or adaptive mechanisms underlying writer's cramp.  相似文献   
87.
88.
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.  相似文献   
89.
90.
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   
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