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   786篇
  免费   55篇
耳鼻咽喉   1篇
儿科学   20篇
妇产科学   18篇
基础医学   82篇
口腔科学   27篇
临床医学   63篇
内科学   190篇
皮肤病学   11篇
神经病学   94篇
特种医学   31篇
外科学   78篇
综合类   8篇
预防医学   103篇
眼科学   15篇
药学   64篇
中国医学   2篇
肿瘤学   34篇
  2023年   7篇
  2022年   14篇
  2021年   45篇
  2020年   11篇
  2019年   29篇
  2018年   35篇
  2017年   24篇
  2016年   25篇
  2015年   23篇
  2014年   30篇
  2013年   37篇
  2012年   49篇
  2011年   60篇
  2010年   35篇
  2009年   28篇
  2008年   36篇
  2007年   57篇
  2006年   31篇
  2005年   21篇
  2004年   19篇
  2003年   19篇
  2002年   19篇
  2001年   17篇
  2000年   13篇
  1999年   18篇
  1998年   5篇
  1997年   3篇
  1996年   4篇
  1995年   4篇
  1992年   3篇
  1991年   9篇
  1990年   10篇
  1989年   3篇
  1988年   11篇
  1987年   6篇
  1986年   8篇
  1985年   4篇
  1984年   8篇
  1983年   7篇
  1982年   5篇
  1981年   2篇
  1980年   4篇
  1979年   4篇
  1978年   4篇
  1977年   7篇
  1976年   2篇
  1975年   7篇
  1974年   7篇
  1972年   2篇
  1971年   4篇
排序方式: 共有841条查询结果,搜索用时 312 毫秒
41.
42.
43.
INTRODUCTION AND OBJECTIVE: Treatment of acute myocardial infarction by percutaneous coronary intervention with stenting leads to excellent immediate clinical results and a good prognosis. The aim of this study was to compare in this selected population the safety and effectiveness of radial artery access versus femoral artery access. PATIENTS AND METHOD: Between May 2001 and June 2003, 162 consecutive patients with acute myocardial infarction < 12 hours treated by percutaneous stenting were included in an observational study. The radial artery approach was used in 103 patients, and the femoral artery approach in the remaining 59 patients. The success of the procedure, incidence of major adverse cardiac events and local puncture complications were compared in patients treated with the radial artery versus the femoral artery approach. RESULTS: Fluoroscopy time (22.4 [15.4] min vs 24.5 [19.5] min), immediate success of the procedure (96.1% vs 94.9%), and the incidence of major adverse cardiac events (6.8% vs 8.5%) did not differ between the two groups. Bleeding complications due to local puncture were present only in the femoral artery access group (0 vs 5 patients; P= .007). CONCLUSIONS: In selected patients with acute myocardial infarction treated with primary stent implantation, the success rate and clinical safety of the radial artery approach are similar to those of the femoral artery approach, but the incidence of local complications, especially bleeding, is significantly lower in the former. Thus the radial artery approach should become the approach of choice in patients at high risk for bleeding complications.  相似文献   
44.
45.
The molecular hallmarks of inflammation-mediated lung carcinogenesis have not been fully clarified, mainly due to the scarcity of appropriate animal models. We have used a silica-induced multistep lung carcinogenesis model driven by chronic inflammation to study the evolution of molecular markers and genetic alterations. We analyzed markers of DNA damage response (DDR), proliferative stress, and telomeric stress: γ-H2AX, p16, p53, and TERT. Lung cancer-related epigenetic and genetic alterations, including promoter hypermethylation status of p16(CDKN2A), APC, CDH13, Rassf1, and Nore1A, as well as mutations of Tp53, epidermal growth factor receptor, K-ras, N-ras, and c-H-ras, have been also studied. Our results showed DDR pathway activation in preneoplastic lesions, in association with inducible nitric oxide synthase and p53 induction. p16 was also induced in early tumorigenic progression and was inactivated in bronchiolar dysplasias and tumors. Remarkably, lack of mutations of Ras and epidermal growth factor receptor, and a very low frequency of Tp53 mutations suggest that they are not required for tumorigenesis in this model. In contrast, epigenetic alterations in p16(CDKN2A), CDH13, and APC, but not in Rassf1 and Nore1A, were clearly observed. These data suggest the existence of a specific molecular signature of inflammation-driven lung carcinogenesis that shares some, but not all, of the molecular landmarks of chemically induced lung cancer.  相似文献   
46.
Among the tests currently available for diagnosis of gastroesophageal reflux (GER), esophageal manometry is the hardest to perform in alert children because of their lack of cooperation. Therefore, it is usually performed under some form of sedation. In an attempt to investigate whether medication by itself modifies esophageal motility, we compared the manometric data of 18 children with pH-probe documented GER before and after sedation (meperidine 1.5 mg/kg, chlorpromazine 1 mg/kg, promethazine 1 mg/kg i.m.). Sedation induced the following changes in motor function compared to that in the unsedated state: (1) lower esophageal sphincter pressure decreased from 16.4 ± 7.3 to 11.4 ± 6.9 (P <0.001), whereas sphincter length remained unchanged; (2) esophageal peristaltic activity almost disappeared in terms of number of waves per hour (106.4 ± 60.1 vs 3.8 ± 6.2, P <0.001) while nonpropulsive activity became predominant, although only in relative terms (percent of tertiary waves 16.5 ± 13.9 vs 75.1 ± 25, P <0.001); (3) the mean pressure of the propulsive waves was also significantly decreased (65.2 ± 20.6 vs 37.9 ± 26.5, P <0.001), and as a result, esophageal motor efficiency (number of primary waves per hour multiplied by the mean pressure of the waves in mmHg) decreased enormously (from 6681.7 ± 4113.7 to 223.9 ± 372.6, P <0.001). Comparison with a group of sedated controls demonstrated that, under equal conditions, both barrier and pump functions were significantly weakened in refluxing patients. The limited diagnostic value of manometry thus remains unquestioned by the present study. Our data suggest that: (1) motor behavior of the esophagus in unsedated children with GER is quite close to that observed in refluxing adults; and (2) sedation of itself substantially modifies the esophageal sphincter barrier and esophageal propulsive pump. If sedation is to be used for manometric studies in children, the results so obtained should only be compared to those of controls under the same conditions.Investigation partially supported by a FISSS Grant (87/1605) Offprint requests to: J. A. Tovar  相似文献   
47.
CASE REPORT: Ocular phenotypes in an affected male and a female carrier with choroideremia are described. COMMENT: Choroideremia is a degenerative retinal disease recognized in the late stages by a near total absence of the choriocapillaris, retinal pigment epithelium and neurosensory retina. Inheritance is X-linked recessive, with males being affected and females acting as carriers. Clinical manifestations include decreased night vision, central vision affected in late stages, peripheral constriction in the visual field and abnormal electroretinogram early in the course of the disease.  相似文献   
48.
49.

Background  

We used a validated inpatient satisfaction questionnaire to evaluate the health care received by patients admitted to several hospitals. This questionnaire was factored into distinct domains, creating a score for each to assist in the analysis.  相似文献   
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