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   1067054篇
  免费   63121篇
  国内免费   2333篇
耳鼻咽喉   13557篇
儿科学   35100篇
妇产科学   28977篇
基础医学   142293篇
口腔科学   26167篇
临床医学   86403篇
内科学   212450篇
皮肤病学   19614篇
神经病学   86973篇
特种医学   44909篇
外国民族医学   336篇
外科学   169677篇
综合类   21290篇
一般理论   247篇
预防医学   81761篇
眼科学   22742篇
药学   72871篇
中国医学   2421篇
肿瘤学   64720篇
  2018年   30125篇
  2017年   23839篇
  2016年   26439篇
  2015年   9576篇
  2014年   13102篇
  2013年   19876篇
  2012年   32265篇
  2011年   47347篇
  2010年   34574篇
  2009年   26782篇
  2008年   44748篇
  2007年   48456篇
  2006年   28344篇
  2005年   29447篇
  2004年   29494篇
  2003年   29594篇
  2002年   27370篇
  2001年   41599篇
  2000年   42935篇
  1999年   36408篇
  1998年   10142篇
  1997年   9335篇
  1996年   9151篇
  1995年   8532篇
  1994年   8168篇
  1993年   7637篇
  1992年   28220篇
  1991年   27054篇
  1990年   26520篇
  1989年   25410篇
  1988年   23599篇
  1987年   23204篇
  1986年   22267篇
  1985年   21176篇
  1984年   15822篇
  1983年   13496篇
  1982年   8110篇
  1979年   14591篇
  1978年   10216篇
  1977年   8629篇
  1976年   8154篇
  1975年   8964篇
  1974年   10716篇
  1973年   10183篇
  1972年   9661篇
  1971年   8917篇
  1970年   8602篇
  1969年   8042篇
  1968年   7698篇
  1967年   7086篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
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   
74.
75.
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   
76.
目的:描述胚胎种植前遗传诊断在1例携带Ⅰ型白细胞黏附缺陷病(LAD-1)携带者并完成健康妊娠夫妇中的应用。设计:病例报道。机构:大学医院生殖中心。患者:1例男女双方都是LAD-1携带者的夫妇,女方CD18基因的外显子4携带有G400A置换,男方的外显子5携带有C562T置换。干预:标准体外受精(IVF)后第3天行卵裂期活检和分裂球遗传分析以检测2处突变以及21号染色体标记物。主要观察指标:1个未罹患LAD-1婴儿的出生。结果:得到15个卵母细胞,其中10个受精。8个胚胎适宜胚胎活组织检查。  相似文献   
77.
Setting goals to maintain hope.   总被引:3,自引:0,他引:3  
  相似文献   
78.
79.
80.
Sniff nasal inspiratory pressure (SNIP) measurement is a volitional noninvasive assessment of inspiratory muscle strength. A maximum of 10 sniffs is generally used. The purpose of the present study was to investigate whether the maximum SNIP improved after the tenth sniff. In total, 20 healthy volunteers and 305 patients with various neuromuscular and lung diseases were encouraged to perform 40 and 20 sniffs, respectively. The best SNIP among the first 10 sniffs was lower than the best SNIP among the next 10 sniffs in the healthy volunteers and patients. The SNIP improvement after the twentieth sniff was marginal. In conclusion, a learning effect persists after the tenth sniff. The current authors suggest using 10 additional sniffs when the best result of the first 10 sniffs is slightly below normal, or when sniff nasal inspiratory pressure is used to monitor a progressive decline in inspiratory muscle strength.  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