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   131007篇
  免费   9453篇
  国内免费   254篇
耳鼻咽喉   1196篇
儿科学   3640篇
妇产科学   2728篇
基础医学   20597篇
口腔科学   3393篇
临床医学   11145篇
内科学   26411篇
皮肤病学   2254篇
神经病学   12605篇
特种医学   5407篇
外国民族医学   16篇
外科学   16261篇
综合类   560篇
现状与发展   1篇
一般理论   108篇
预防医学   14916篇
眼科学   2028篇
药学   7885篇
  1篇
中国医学   240篇
肿瘤学   9322篇
  2023年   560篇
  2022年   934篇
  2021年   2022篇
  2020年   1469篇
  2019年   2138篇
  2018年   2687篇
  2017年   2287篇
  2016年   2462篇
  2015年   2787篇
  2014年   3779篇
  2013年   4987篇
  2012年   7662篇
  2011年   7721篇
  2010年   3993篇
  2009年   4219篇
  2008年   6843篇
  2007年   7062篇
  2006年   6815篇
  2005年   6457篇
  2004年   5478篇
  2003年   5205篇
  2002年   4740篇
  2001年   4584篇
  2000年   4586篇
  1999年   4083篇
  1998年   1692篇
  1997年   1390篇
  1996年   1466篇
  1995年   1203篇
  1994年   1124篇
  1993年   1017篇
  1992年   2781篇
  1991年   2516篇
  1990年   2396篇
  1989年   2234篇
  1988年   2051篇
  1987年   1801篇
  1986年   1720篇
  1985年   1637篇
  1984年   1168篇
  1983年   1013篇
  1982年   542篇
  1981年   479篇
  1980年   411篇
  1979年   887篇
  1978年   538篇
  1977年   443篇
  1974年   448篇
  1973年   435篇
  1972年   389篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Obesity is a risk factor for renal graft loss. Higher body mass index (BMI) in native kidneys is associated with glomerular hyperfiltration. Whether higher BMI in renal transplants is associated with hyperfiltration is unknown. We investigated the impact of BMI on renal hemodynamics 1 year post-transplant. We analyzed glomerular filtration rate (GFR, (125)I-iothalamate) and effective renal plasma flow (ERPF, (131)I-hippurate) in 838 kidney transplants. Data were analyzed for all patients and for the subpopulation without diabetes. Long-term impact of BMI and renal hemodynamics were explored by Cox-regression. With higher BMI GFR and filtration fraction (FF) increased significantly. Multivariate analysis supported impact of BMI on GFR (adjusted r(2) of the model 0.275) and FF (adjusted r(2) of the model 0.158). This association was not explained by diabetes mellitus. On Cox-regression analysis, lower GFR and higher FF were independent determinants of overall graft loss and graft loss by patient mortality. Lower GFR and higher BMI were determinants of death-censored graft loss, with borderline contribution of higher FF. In renal transplants higher BMI is independently associated with higher GFR and FF one year posttransplant, suggesting glomerular hyperfiltration with altered afferent-efferent balance. Mechanisms underlying the long-term prognostic impact of hyperfiltration deserve further exploration.  相似文献   
52.
Trauma und Berufskrankheit - Die Vermeidung gepuderter Latexhandschuhe gilt als wichtige Maßnahme zur Prävention von latexbedingten Haut- und Atemwegsallergien bei Beschäftigten im...  相似文献   
53.
54.
55.
56.
Epidemiologic studies have shown that blood pressure increases more rapidly in middle-aged women than in middle-aged men. Whether or not ovarian failure contributes to this rapid rise is still not clear. In a follow-up study begun in 1979 and to continue for 10 years, the blood pressure of 193 healthy normotensive perimenopausal women, who lived in the mixed rural/industrial community of Ede, the Netherlands and who were initially aged between 49 and 56 years, was measured annually. During the course of the study, the onset of menopause of each participant could be established. Because of the mixed longitudinal design of the study, it was possible to evaluate the effects of both chronologic aging and time pre- or postmenopause on blood pressure. After the first seven years of follow-up, it was demonstrated that blood pressure did not increase in 168 women whose body weight was relatively stable. After multivariate analyses, systolic as well as diastolic pressure showed a significant negative relation (slope, 1.34 mmHg per year and 0.63 mmHg per year, respectively) with the years since menopause. On the other hand, the observed positive relation (slope, 0.81 mmHg per year) of systolic pressure with chronologic aging was not significant. No consistent association was found between diastolic pressure and chronologic aging. It is concluded that menopause cannot be regarded as a cause of hypertension; on the contrary, ovarian failure appears to have a protective effect on the increase in blood pressure as a result of chronologic aging. on the increase in blood pressure as a result of chronologic aging.  相似文献   
57.
58.
In the past few years several studies have supported an interplay between cytomegalovirus infections and a prothrombotic state. We describe a case of primary cytomegalovirus infection in an immunocompetent adult that was complicated with mesenteric vein thrombosis. Transient protein C deficiency, lupus anticoagulant and activated protein C resistance were found, in combination with a heterozygous prothrombin G20210A mutation. We discuss the possible mechanisms of cytomegalovirus-related venous thrombosis.  相似文献   
59.
60.
Tracking performance was investigated in normal and clumsy children in two age-groups, six to seven and 10 to 11 years. Target signals moving unpredictably along a straight line had to be tracked, both with and without visual feedback. Performance was described in three ways: (1) performance in the low-frequency range (LF); (2) the delay between target signal and tracking movement (DL); and (3) a measure of tracking quality or over-all similarity in the shape of target signal and tracking movement (Q). Clumsy children in both age-groups had a lower tracking quality (Q) and longer delay (DL) than the normal children. Disturbances in the regulation of attention seemed to affect tracking performance, particularly of the six- to seven-year-old clumsy children. There was no significant difference between normal and clumsy children in the effect of visual feedback on tracking performance. This suggests that clumsiness is not linked to disturbance of integration of visual feedback information and motor processes.  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