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   29600篇
  免费   1834篇
  国内免费   184篇
耳鼻咽喉   385篇
儿科学   857篇
妇产科学   773篇
基础医学   3116篇
口腔科学   810篇
临床医学   2425篇
内科学   6503篇
皮肤病学   620篇
神经病学   1416篇
特种医学   959篇
外国民族医学   11篇
外科学   5184篇
综合类   812篇
现状与发展   1篇
一般理论   30篇
预防医学   2040篇
眼科学   876篇
药学   2585篇
中国医学   198篇
肿瘤学   2017篇
  2023年   401篇
  2022年   1176篇
  2021年   1679篇
  2020年   867篇
  2019年   1091篇
  2018年   1450篇
  2017年   890篇
  2016年   923篇
  2015年   1064篇
  2014年   1348篇
  2013年   1550篇
  2012年   2219篇
  2011年   2283篇
  2010年   1246篇
  2009年   998篇
  2008年   1480篇
  2007年   1563篇
  2006年   1401篇
  2005年   1244篇
  2004年   1145篇
  2003年   1012篇
  2002年   887篇
  2001年   382篇
  2000年   358篇
  1999年   330篇
  1998年   207篇
  1997年   139篇
  1996年   135篇
  1995年   126篇
  1994年   90篇
  1993年   73篇
  1992年   154篇
  1991年   135篇
  1990年   129篇
  1989年   118篇
  1988年   114篇
  1987年   103篇
  1986年   104篇
  1985年   101篇
  1984年   82篇
  1983年   104篇
  1982年   57篇
  1981年   57篇
  1980年   43篇
  1979年   84篇
  1978年   56篇
  1977年   55篇
  1976年   45篇
  1975年   48篇
  1974年   46篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
We describe 100 consecutive patients with histologically proven gastric carcinoma who were admitted to various hospitals in Northern Pakistan. Twenty-six per cent of patients were under 40 years of age. In a majority of patients the tumour was of a morphological type associated with poor prognosis. In most cases the disease was already at an advanced stage at the time of diagnosis, and most patients died within one year.  相似文献   
42.
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   
43.
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   
44.
45.
46.
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   
47.
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   
48.
49.
50.
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