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   42218篇
  免费   2682篇
  国内免费   209篇
耳鼻咽喉   317篇
儿科学   1553篇
妇产科学   1233篇
基础医学   5021篇
口腔科学   594篇
临床医学   6825篇
内科学   7762篇
皮肤病学   489篇
神经病学   3799篇
特种医学   1017篇
外国民族医学   1篇
外科学   4459篇
综合类   521篇
现状与发展   1篇
一般理论   60篇
预防医学   5102篇
眼科学   711篇
药学   2523篇
中国医学   129篇
肿瘤学   2992篇
  2023年   235篇
  2022年   367篇
  2021年   813篇
  2020年   549篇
  2019年   877篇
  2018年   1063篇
  2017年   748篇
  2016年   825篇
  2015年   919篇
  2014年   1297篇
  2013年   2004篇
  2012年   2938篇
  2011年   3080篇
  2010年   1666篇
  2009年   1491篇
  2008年   2802篇
  2007年   2992篇
  2006年   2905篇
  2005年   2789篇
  2004年   2584篇
  2003年   2412篇
  2002年   2277篇
  2001年   610篇
  2000年   576篇
  1999年   596篇
  1998年   513篇
  1997年   417篇
  1996年   350篇
  1995年   376篇
  1994年   283篇
  1993年   282篇
  1992年   313篇
  1991年   288篇
  1990年   276篇
  1989年   269篇
  1988年   240篇
  1987年   219篇
  1986年   215篇
  1985年   198篇
  1984年   193篇
  1983年   178篇
  1982年   184篇
  1981年   174篇
  1980年   149篇
  1979年   89篇
  1978年   92篇
  1977年   84篇
  1976年   61篇
  1975年   47篇
  1974年   52篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
991.
Summary Diabetic microangiopathy may be associated with the pathogenesis and progression of autonomic and peripheral neuropathy. In 17 long-standing type I diabetic patients with peripheral and autonomic cardiovascular neuropathy, several hemorheological and hemostatic alterations were found compared to 13 matched type I patients without neuropathy. In particular, increased plasma von Willebrand factor antigen (p<0.001), fibronectin (p<0.001) and fibrinogen (p<0.001) levels were demonstrated in neuropathic in comparison with non-neuropathic diabetic patients. Moreover negative correlations between these parameters and both motor and sensitive conduction velocity of median, sural and peroneal nerves were observed in diabetic patients with neuropathy. Higher blood viscosity (p<0.05 at shear-rate of 450 and 225 s−1; p<0.01 at 90 s−1; p<0.001 at 4.5 and 2.25 s−1), plasma viscosity (p<0.001) and lower erythrocyte filtrability (p<0.001) were also found in neuropathic compared to non-neuropathic diabetics. Increased prevalence of retinopathy (p<0.01) and nephropathy (p<0.001) was finally reported in patients with autonomic and peripheral neuropathy. Microvascular disease may be involved in the development of neuropathy in long-term type I diabetes mellitus. This study was presented in part at the 23rd Annual Meeting of the European Association for the Study of Diabetes, Leipzig (GDR), 15–19 September 1987.  相似文献   
992.
993.
994.
Hui CK  Lie A  Au WY  Leung YH  Ma SY  Cheung WW  Zhang HY  Chim CS  Kwong YL  Liang R  Lau GK 《Blood》2005,106(2):464-469
The long-term hepatic complications after allogeneic hematopoietic stem cell transplantation (HSCT) in hepatitis B virus (HBV) endemic area are unknown. We examined the serological and liver-related outcome of 803 consecutive patients who received allogeneic HSCTs, with a median follow-up period of 83 months (range, 0.5-155 months). Late HBV-related hepatitis occurred in 2 of the 721 hepatitis B surface antigen-negative (HBsAg-) recipients compared with 16 of the 82 HBsAg+ recipients after HSCT (0.3% vs 19.5%; P < .001 by log-rank). Liver cirrhosis developed in 8 of the 82 HBsAg+ recipients compared with none of the 721 HBsAg- recipients (9.8% vs 0%; P < .001 by log-rank). Twenty of the 31 (64.5%) HBsAg+ recipients of hematopoietic stem cells from donors with natural immunity to HBV had sustained serologic clearance of HBsAg after HSCT. Eight of the 62 recipients without sustained HBsAg clearance compared with none of the 20 recipients with sustained HBsAg clearance developed liver cirrhosis (12.9% vs 0%; P = .02 by log-rank). Our study showed that long-term hepatic complications occur in a significant proportion of HBsAg+ patients after HSCT and the incidence of liver cirrhosis is reduced in those with sustained serologic clearance of HBsAg after HSCT.  相似文献   
995.
OBJECTIVES: We aimed to assess the Severity of Dyspepsia Assessment (SODA) scales as measures of change in dyspepsia-related health in a blinded, randomized, controlled trial in arthritis patients treated with nonsteroidal anti-inflammatory drugs. METHODS: Three thousand nine hundred seven arthritis patients completed SODA at baseline and weeks 4, 13, 26, and 52 and/or at early termination. Using baseline and 4-wk data, reliability was evaluated with Cronbach's a and the intraclass correlation coefficient (ICC). Dyspepsia adverse events were defined based on a combined set of World Health Organization Adverse Reaction Terminology terms. The ability of SODA to measure change in dyspepsia-related health was evaluated by comparing SODA change scores by dyspepsia adverse event severity level and withdrawal status. Responsiveness was further evaluated by the area under the curve (AUC) from receiver operating characteristic curves using withdrawal due to dyspepsia as the criterion. RESULTS: The SODA scales--Pain Intensity (alpha = 0.93), Non Pain Symptoms (alpha = 0.82), and Satisfaction (alpha = 0.89)--demonstrated excellent internal consistency reliability using baseline data. Reproducibility was fair to good: Pain Intensity ICC = 0.49, Non Pain Symptoms ICC = 0.61, and Satisfaction ICC = 0.45. SODA change scores (4-wk score - baseline score) increased, or worsened, with increasing dyspepsia severity and differentiated between adjacent levels of dyspepsia severity for eight of nine adjacent comparisons (p < 0.05). SODA change scores also differentiated between those who did and did not withdraw (p < 0.001). Responsiveness was highest with the Pain Intensity scale (AUC = 0.78), followed by the Non Pain Symptoms (AUC = 0.74) and Satisfaction (AUC = 0.75) scales. CONCLUSIONS: SODA is a reliable, valid instrument for use as a measure of dyspepsia tolerability in future clinical trials involving cyclo-oxygenase-2-specific and/or traditional nonsteroidal anti-inflammatory drugs.  相似文献   
996.
Patients with cirrhosis require endoscopic screening for large esophageal varices. The aims of this study were to determine the cost-effectiveness and patient preferences of a strategy employing abdominal computerized tomography (CT) as the initial screening test for identifying large esophageal varices. In a prospective evaluation,102 patients underwent both CT and endoscopic screening for gastroesophageal varices. Two radiologists read each CT independently; standard upper gastrointestinal endoscopy was the reference standard. Agreement between radiologists, and between endoscopists regarding size of varices was determined using kappa statistic. Cost-effectiveness analysis was performed to determine the optimal screening strategy for varices. Patient preference was assessed by questionnaire. CT was found to have approximately 90% sensitivity in the identification of esophageal varices determined to be large on endoscopy, but only about 50% specificity. The sensitivity of CT in detecting gastric varices was 87%. In addition, a significant number of gastric varices, peri-esophageal varices, and extraluminal pathology were identified by CT that were not identified by endoscopy. Patients overwhelmingly preferred CT over endoscopy. Agreement between radiologists was good regarding the size of varices (Kappa = 0.56), and exceeded agreement between endoscopists (Kappa = 0.36). Use of CT as the initial screening modality for the detection of varices was significantly more cost-effective compared to endoscopy irrespective of the prevalence of large varices. CONCLUSION: Abdominal CT as the initial screening test for varices could be cost-effective. CT also permits evaluation of extra-luminal pathology that impacts management.  相似文献   
997.
998.
999.
Eosinophils stimulate fibroblast DNA synthesis   总被引:9,自引:0,他引:9  
Pincus  SH; Ramesh  KS; Wyler  DJ 《Blood》1987,70(2):572-574
Fibrosis complicates a number of chronic inflammatory diseases and occurs in some conditions following chronic hypereosinophilic syndromes. We assessed whether eosinophils might be a source of fibrogenic factors. Extracts of human and guinea pig cell populations enriched for eosinophils contained substances that stimulated tritiated thymidine incorporation by human fibroblasts. Supernatants derived from resting eosinophils and extracts prepared from eosinophil granules also contained fibrogenic factors. Our findings demonstrate a new potential role for eosinophils and suggest a causal relationship between tissue eosinophilia and scar formation in certain parasitic conditions.  相似文献   
1000.
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