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   5920篇
  免费   463篇
  国内免费   17篇
耳鼻咽喉   34篇
儿科学   116篇
妇产科学   82篇
基础医学   1100篇
口腔科学   122篇
临床医学   522篇
内科学   1146篇
皮肤病学   171篇
神经病学   704篇
特种医学   272篇
外科学   492篇
综合类   13篇
一般理论   6篇
预防医学   587篇
眼科学   145篇
药学   342篇
中国医学   15篇
肿瘤学   531篇
  2024年   4篇
  2023年   58篇
  2022年   85篇
  2021年   185篇
  2020年   120篇
  2019年   164篇
  2018年   164篇
  2017年   186篇
  2016年   195篇
  2015年   236篇
  2014年   256篇
  2013年   343篇
  2012年   519篇
  2011年   520篇
  2010年   295篇
  2009年   276篇
  2008年   399篇
  2007年   432篇
  2006年   374篇
  2005年   366篇
  2004年   309篇
  2003年   292篇
  2002年   233篇
  2001年   40篇
  2000年   30篇
  1999年   44篇
  1998年   39篇
  1997年   38篇
  1996年   19篇
  1995年   19篇
  1994年   26篇
  1993年   15篇
  1992年   15篇
  1991年   11篇
  1990年   7篇
  1989年   13篇
  1988年   4篇
  1987年   10篇
  1986年   4篇
  1985年   3篇
  1983年   4篇
  1982年   9篇
  1981年   7篇
  1980年   8篇
  1979年   3篇
  1978年   5篇
  1977年   5篇
  1974年   4篇
  1960年   1篇
  1959年   1篇
排序方式: 共有6400条查询结果,搜索用时 31 毫秒
1.
2.
3.
AIMS: To evaluate the predictive accuracy of the Systematic Coronary Risk Evaluation (SCORE) project high-risk function in Norway. METHODS AND RESULTS: We included 57 229 individuals screened in 1985-1992 from two population-based surveys in Norway (age groups 40-49, 50-59, and 60-69 years). The data have been linked to the Norwegian Cause of Death Registry. The SCORE high-risk algorithm for the prediction of 10-year cardiovascular disease (CVD) mortality was applied, and the risk factors entered into the model were age, sex, total cholesterol, systolic blood pressure, and smoking (yes/no). The number of expected events estimated by the SCORE model (E) was compared with the observed numbers (O). The SCORE low-risk algorithm was studied for comparison. In men, the observed number of CVD deaths was 718, compared with 1464 estimated by the SCORE high-risk function (O/E ratios 0.53, 0.53 and 0.45, for age groups 40-49, 50-59 and 60-69, respectively). In women, the observed and expected numbers were 226 and 547. The O/E ratios decreased with age (ratios 0.60, 0.45 and 0.37, respectively), i.e. the overestimation increased with age. The low-risk function predicted reasonably well for men (ratios 0.85, 0.92 and 0.79, respectively), whereas an overestimation was found for women aged 50-59 and 60-69 years (ratios 0.69 and 0.56, respectively). CONCLUSION: The SCORE high-risk model overestimated the number of CVD deaths in Norway. Before implementation in clinical practice, proper adjustments to national levels are required.  相似文献   
4.
5.
6.
Circulating monocytes from hypertensive patients show elevated secretion patterns of pro-inflammatory cytokines, an increased expression of adhesion molecules, and an increased adhesion to vascular endothelial cells. We tested the hypothesis that telmisartan, an angiotensin II type 1 (AT(1)) receptor antagonist, reduces the activation of circulating monocytes from hypertensive patients and diminishes the monocyte-endothelial cell adhesion. Monocytes of 20 hypertensive patients and 20 normotensive controls were isolated by density gradient centrifugation and Dynabeads, and the monocyte adhesion to human aortic endothelial cell monolayers was measured by adhesion assays. To characterize monocyte activation we assessed the expression of activity-related cell surface markers that are also involved in monocyte adhesion to endothelial cells, such as CD11a/b and CD54, as well as the chemokine receptors CCR1, CCR2 and CCR5 before and after telmisartan therapy using flow cytometry. Spontaneous adhesion of monocytes from hypertensive patients and the adhesion after stimulation with angiotensin II were significantly increased compared with those in normotensive controls (p<0.05). Treatment of hypertensive patients with the AT(1) receptor antagonist telmisartan significantly diminished the adhesion of circulating monocytes to human endothelial cells (p=0.02) despite the increase in the expressions of CD11b, CD54 and CCR5 after telmisartan therapy. Reducing monocyte adhesion may be a novel beneficial effect of the AT(1) receptor antagonist telmisartan helping to prevent vascular alterations in hypertension. The mechanism of action remains to be elucidated, since reduction in monocyte adhesion was not attributable to changes in adhesion molecule expression.  相似文献   
7.
Prion infections of the central nervous system (CNS) are characterised by a reactive gliosis and the subsequent degeneration of neuronal tissue. The activation of glial cells, which precedes neuronal death, is likely to be initially caused by the deposition of misfolded, proteinase K-resistant, isoforms (termed PrP(res)) of the prion protein (PrP) in the brain. Cytokines and chemokines released by PrP(res)-activated glia cells may contribute directly or indirectly to the disease development by enhancement and generalisation of the gliosis and via cytotoxicity for neurons. However, the actual role of prion-induced glia activation and subsequent cytokine/chemokine secretion in disease development is still far from clear. In the present work, we review our present knowledge concerning the functional biology of cytokines and chemokines in prion infections of the CNS.  相似文献   
8.
A community organization strategy was used in the delivery of health education programs by the Minnesota Heart Health Program (MHHP). The effectiveness of the approach was evaluated to determine whether an enhanced health promotion delivery system had developed in MHHP communities by the end of the intervention period or whether the intervention had suppressed community efforts. 'Social connectedness' among providers, as measured by health promotion network size, also was expected to be higher in intervention communities. Six Midwestern communities were studied: the MHHP communities of Mankato, MN and Fargo, ND--Moorhead, MN with two matched comparison communities for each (Winona, MN, St Cloud, MN and Eau Claire, WI, Sioux Falls, SD). Nine areas of health promotion were assessed, including the five heart disease risk factor areas where education campaigns had been implemented (smoking cessation, weight loss, eating patterns, exercise, and heart disease education and screening) and four other areas where community programs are common (chemical dependency; home, personal and drivers' safety; stress management; and cancer education and screening). Indicators of the health promotion delivery system were developed (program options and program participation), and data were collected in separate surveys of 438 community organization providers and 320 larger worksites in the six communities. Results showed no suppression of health promotion delivery systems in MHHP communities. Instead, the survey of larger worksites showed that there was greater participation in heart disease health promotion and greater 'social connectedness' among worksites in both intervention communities. Also, there were more heart disease health promotion programs in the larger intervention community of Fargo-Moorhead. In the community organization survey, results favored the larger intervention community over its comparison communities in heart disease health promotion program options and in 'social connectedness' but not in program participation. However, survey results favored one of the comparison communities (Winona) over the smaller intervention community (Mankato) on all indicators in this survey. The greater impact of the MHHP intervention at worksites suggests that institutionalization may be more likely in stable organizations whose current needs and interests fit the goals of the intervention activity.  相似文献   
9.
10.
Tactile pattern recognition of ten different patterns which were engraved upon 4 x 4 cm plastic plaquettes with one hand and thereafter drawing with the other or the same hand was tested in 21 patients with a mild stage primary degenerative presenile onset dementia of Alzheimer type (DAT) and in 14 patients with a questionable dementia on the background of a chronic cardiovascular disease (CVD) in comparison to 15 healthy subjects of the same age (51 years old, elder controls, (EC)) and 16 younger subjects (22 years old, younger controls, (YC)). Patients made about four times more errors than the EC group. Duration from the begin of touching to the end of drawing was significantly longer in patients than in controls. In a second task the subjects had to recognize four subsequent patterns, then to perform a standard multiplication task and afterwards to draw all four patterns in their correct sequence. Patients made about ten times more errors in pattern recognition and series reproduction than age-matched controls.  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