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   17743篇
  免费   1428篇
  国内免费   132篇
耳鼻咽喉   179篇
儿科学   703篇
妇产科学   582篇
基础医学   2509篇
口腔科学   314篇
临床医学   1909篇
内科学   3706篇
皮肤病学   269篇
神经病学   1449篇
特种医学   531篇
外科学   2115篇
综合类   243篇
一般理论   20篇
预防医学   1530篇
眼科学   421篇
药学   1148篇
中国医学   130篇
肿瘤学   1545篇
  2023年   105篇
  2022年   172篇
  2021年   432篇
  2020年   288篇
  2019年   427篇
  2018年   435篇
  2017年   332篇
  2016年   386篇
  2015年   434篇
  2014年   606篇
  2013年   782篇
  2012年   1249篇
  2011年   1230篇
  2010年   698篇
  2009年   672篇
  2008年   1140篇
  2007年   1104篇
  2006年   1091篇
  2005年   1015篇
  2004年   980篇
  2003年   898篇
  2002年   794篇
  2001年   452篇
  2000年   421篇
  1999年   378篇
  1998年   208篇
  1997年   162篇
  1996年   137篇
  1995年   132篇
  1994年   111篇
  1993年   118篇
  1992年   214篇
  1991年   181篇
  1990年   170篇
  1989年   172篇
  1988年   146篇
  1987年   137篇
  1986年   128篇
  1985年   117篇
  1984年   91篇
  1983年   62篇
  1982年   61篇
  1981年   52篇
  1980年   33篇
  1979年   42篇
  1978年   32篇
  1977年   29篇
  1974年   24篇
  1973年   29篇
  1972年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
OBJECTIVES: To evaluate the application of a translated version of an established self-administered questionnaire for carpal tunnel syndrome on Chinese patients in Hong Kong. DESIGN: Evaluation of an instrument tool. SETTING: Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong; Holistic Medical Centre, Aberdeen, Hong Kong. PARTICIPANTS: Patients with carpal tunnel syndrome, translators. MAIN OUTCOME MEASURES: The adaptation was based on forward-backward translation from English to Chinese (Hong Kong) and vice versa. Meetings with translators, investigators, and patients were organised to generate an acceptable version of the questionnaire. A pilot study was carried out on 20 patients and subsequently minor adjustments were added. Fifty patients were recruited to validate the reliability and internal consistency of the questionnaire. RESULTS: The ordinality of response agreed with the original instrument. Test-retest reproducibility showed no significant difference between tests. The Pearson correlation coefficient ranged from 0.83 to 0.93. Internal consistency was good, at 0.85. CONCLUSION: Through the validation of the Hong Kong Chinese version of the questionnaire, we are able to produce an assessment tool for the local patients. Furthermore, we are able to create a platform for: (i) a cross-national and cross-cultural epidemiological comparison as well as a means of (ii) evaluating different types of treatments.  相似文献   
52.
The reflectance spectrophotometric technique measures an index of mucosal hemoglobin concentration and an index of oxygen saturation by spectral analysis of light reflected from the mucosal surface. Using a commercially available unit, a technique for obtaining reproducible endoscopic measurements with acceptable intraobserver and interobserver variability was developed in the anesthetized dogs. The reflectance spectrophotometric finding that experimentally induced prehepatic portal hypertension did not affect gastric mucosal blood flow was confirmed by hydrogen gas clearance measurements. Endoscopic studies in patients with active duodenal ulcer disease revealed a higher index of mucosal hemoglobin concentration and a normal index of oxygen saturation (i.e., an increase in blood flow) at the margin of the ulcer compared with the adjacent normal appearing mucosa.  相似文献   
53.
54.
55.
The liver is distinguished from other tissues by (a) its detoxifying function, (b) its resistance to apoptosis, and (c) its regenerative response to damage. Hepatocellular carcinoma arises when chronic insults, such as hepatitis or iron overload, constitutively activate this regenerative program. Here, we propose that the proliferative response of the liver to damage underlies the resistance of hepatocellular carcinoma to cytotoxic therapy, and that hepatocellular carcinoma growth should therefore be more readily controlled by using a networked combination of noncytotoxic interventions to interrupt the damage-inducible regenerative pathway. To this end, hepatocellular carcinoma boasts a wealth of potential drug targets, including viral replication, the antiapoptotic immunosuppressant alpha-fetoprotein, hepatic iron overload, inflammatory signaling, extracellular proteases, and growth factors. By blocking these positive feedback loops in parallel, and so returning the host environment to a more normal state, epigenetic repression of tumor-suppressor gene function may be reversed and tumor dormancy restored. Noncytotoxic maneuvers that short circuit damage resistance loops may thus represent an indirect form of gene therapy meriting incorporation into hepatocellular carcinoma clinical trials.  相似文献   
56.
In the mutilated hand where all the fingers are destroyed, the undamaged mobile thumb will not be capable of performing the important function of making a grip or pinch alone. Under such circumstances, it is worthwhile reconstructing the missing fingers so as to restore this simple but basic function.  相似文献   
57.
Prospective studies suggest that tea may protect against cardiovascular disease. A potential mechanism for such an effect involves inhibition of lipid peroxidation by polyphenolic antioxidants derived from tea. Our objective was to determine whether regular ingestion of tea could inhibit in vivo lipid peroxidation. Two controlled intervention studies assessed the effects of regular ingestion of tea on lipid peroxidation determined by measurement of urinary F(2)-isoprostane excretion. Study 1: The effects of 1000 mL/d of green tea and black tea were compared with hot water containing caffeine in 13 subjects with elevated blood pressure using a randomized 3-period (7 d each) crossover design. Study 2: The effects of 1250 mL/d of black tea were compared with hot water in 22 subjects with mildly raised serum total cholesterol concentrations using a randomized 2-period (4 wk each) crossover design. F(2)-isoprostane excretion was not altered after regular ingestion of green tea (273 +/- 48 pmol/mmol creatinine) or black tea (274 +/- 39 pmol/mmol creatinine) in comparison with hot water (263 +/- 47 pmol/mmol creatinine; Study 1), or by regular ingestion of black tea (334 +/- 71 pmol/mmol creatinine) in comparison with hot water (355 +/- 75 pmol/mmol creatinine; Study 2). These results do not support the suggestion that polyphenolic antioxidants derived from tea inhibit in vivo lipid peroxidation.  相似文献   
58.
Chronic rejection accounted for 32% of all graft losses in 7123 pediatric transplants. In a previous study acute, multiple acute and late acute rejections were risk factors for the development of chronic rejection. We postulated that the recent decrease in acute rejections would translate into a lower risk for chronic rejection among patients with recent transplants. We reviewed our data on patients transplanted from 1995 to 2000, and using multivariate analysis and a proportional hazards model developed risk factors for patients whose grafts had failed due to chronic rejection. A late initial rejection increased the risk of chronic rejection graft failure 3.6-fold (p < 0.001), while a second rejection resulted in further increase of 4.2-fold (p < 0.001). Recipients who received less than 5 mg/kg of cyclosporine at 30 days post-transplant had a relative risk (RR) of 1.9 (p = 0.02). Patients transplanted from 1995 to 2000 had a significantly lower risk (RR = 0.54, p < 0.001) of graft failure from chronic rejection than those who received their transplants earlier (1987-94). Since we were able to demonstrate that there is a decreased risk of chronic rejection graft failure in our study cohort, we would conclude that the goal of future transplants should be to minimize acute rejections.  相似文献   
59.
60.
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