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   25536篇
  免费   1640篇
  国内免费   167篇
耳鼻咽喉   298篇
儿科学   782篇
妇产科学   756篇
基础医学   2601篇
口腔科学   731篇
临床医学   2091篇
内科学   5572篇
皮肤病学   561篇
神经病学   1183篇
特种医学   813篇
外国民族医学   9篇
外科学   4611篇
综合类   742篇
现状与发展   1篇
一般理论   21篇
预防医学   1825篇
眼科学   739篇
药学   2269篇
中国医学   162篇
肿瘤学   1576篇
  2023年   309篇
  2022年   798篇
  2021年   1487篇
  2020年   789篇
  2019年   1001篇
  2018年   1325篇
  2017年   811篇
  2016年   824篇
  2015年   911篇
  2014年   1160篇
  2013年   1396篇
  2012年   1951篇
  2011年   1992篇
  2010年   1062篇
  2009年   853篇
  2008年   1230篇
  2007年   1348篇
  2006年   1165篇
  2005年   1042篇
  2004年   965篇
  2003年   818篇
  2002年   729篇
  2001年   354篇
  2000年   328篇
  1999年   307篇
  1998年   162篇
  1997年   125篇
  1996年   104篇
  1995年   108篇
  1994年   75篇
  1993年   57篇
  1992年   138篇
  1991年   138篇
  1990年   121篇
  1989年   112篇
  1988年   107篇
  1987年   101篇
  1986年   110篇
  1985年   91篇
  1984年   69篇
  1983年   91篇
  1981年   45篇
  1979年   81篇
  1978年   45篇
  1977年   60篇
  1976年   43篇
  1975年   44篇
  1974年   42篇
  1973年   39篇
  1972年   42篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
71.
There are significant variations among countries in the incidence of brain abscess. We report here 26 cases of brain abscess treated at the Neurosurgery Department of King Faisal University and Dammam Central Hospital Saudi Arabia over a six year period (1982–1988). This is 2.3% of total admissions to the two neurosurgery departments serving a population of approximately 1.2 million in the same period.Young males were most often affected (M/F ratio 3.3:1; 31% were less than 15 years old, 46% aged between 15–39 years, and 23% older than 40 years). Streptococcus was found to be the most common microorganism (38.4%). Mixed infection was seen in 15.3%, and sterile abscesses were found in 11.5% of the patients after aerobic and anaerobic cultures of the pus. Chronic otitis media and paranasal sinusitis predisposed the patients to abscess formation in 57.6% of the cases. The temporo-parietal area was the commonest site. Epilepsy was a complication in 30.7% of our patients, and the mortality rate was 15.3%.  相似文献   
72.
The antibacterial activity of the volatile oil of Nigella sativa seeds was studied against 37 isolates of Shigella dysenteriae 1, Shigella flexneri, Shigella sonnei and Shigella boydii and 10 strains of Vibrio cholerae and Escherichia coli. Most of the strains were clinically resistant to ampicillin, co-trimoxazole and tetracycline. All the strains tested showed promising sensitivity to the volatile oil. The minimum inhibitory concentration (MIC) of the volatile oil for Shigella, Vibrio and Escherichia strains tested was between 50–400 μg/mL.  相似文献   
73.
74.
75.
OBJECTIVE: Heart failure (HF) and depression are both common in older adults, and the presence of depression is known to worsen HF outcomes. For community-dwelling older adults, admission to a nursing home (NH) is associated with loss of independent living and poor outcomes. The objective of this study was to examine the effect of depression on NH admission for older adults with HF. METHODS: Using the 2001-2003 National Hospital Discharge Survey datasets, the authors identified all community-dwelling older adults who were discharged alive with a primary discharge diagnosis of HF. The authors then identified those with a secondary diagnosis of depression. Using a multivariable logistic regression model, the authors then determined probability or propensity to have depression for each patient. The authors used propensity scores for depression to match all 680 depressed patients with 2,040 nondepressed patients. Finally, the authors estimated the association between depression and NH admission using bivariate and multivariable logistic regression analyses. RESULTS: Patients had a mean (+/- standard deviation) age of 79 (+/- 8) years, 72% were women, and 9% were blacks. Compared with 17% nondepressed patients, 25% depressed patients were discharged to a NH. Depression was associated with 50% increased risk of NH admission (unadjusted relative risk [RR]: 1.50; 95% confidence interval [CI]: 1.28-1.74). The association became somewhat stronger after multivariable adjustment for various demographic and care covariates (adjusted RR: 1.60; 95% CI: 1.35-1.68). CONCLUSION: In ambulatory older adults hospitalized with HF, a secondary diagnosis of depression was associated with a significant increased risk of NH admission.  相似文献   
76.
BACKGROUND: Thiazolidinediones (TZD) have been reported to improve early stages of diabetic nephropathy independent of glycaemic control. Since blockade of the renin-angiotensin system (RAS) is known to reduce the risk of nephropathy, we hypothesised that the renal effect of TZDs might be related to a favourable effect on the intrarenal RAS. We aimed to determine if the TZD rosiglitazone could reduce RAS activation. METHODS: We studied adult type 2 diabetic patients and placed them on rosiglitazone for three months. We have previously used the renal haemodynamic response to angiotensin-converting enzyme (ACE) inhibition to demonstrate the state of RAS activation, and thus measured renal plasma flow (RPF) and glomerular filtration rate (GFR) before and after administration of captopril at 0 month and at three months. Plasma renin activity (PRA), active renin, aldosterone and natriuretic peptides were analysed. RESULTS: The RPF response to ACE inhibition was not altered. There was no change in GFR, PRA, active renin and aldosterone levels. Two patients developed oedema one had an elevated baseline active renin and another had an elevated baseline aldosterone level. CONCLUSION: The favourable effects of TZDs on diabetic nephropathy is likely not related to an influence on the RAS.  相似文献   
77.
78.
79.
80.
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