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   3012篇
  免费   171篇
  国内免费   27篇
耳鼻咽喉   15篇
儿科学   84篇
妇产科学   75篇
基础医学   362篇
口腔科学   40篇
临床医学   364篇
内科学   818篇
皮肤病学   111篇
神经病学   143篇
特种医学   273篇
外科学   306篇
综合类   33篇
预防医学   121篇
眼科学   46篇
药学   194篇
中国医学   1篇
肿瘤学   224篇
  2023年   15篇
  2022年   25篇
  2021年   49篇
  2020年   22篇
  2019年   27篇
  2018年   51篇
  2017年   37篇
  2016年   48篇
  2015年   36篇
  2014年   65篇
  2013年   94篇
  2012年   125篇
  2011年   140篇
  2010年   100篇
  2009年   111篇
  2008年   123篇
  2007年   141篇
  2006年   128篇
  2005年   113篇
  2004年   102篇
  2003年   115篇
  2002年   116篇
  2001年   119篇
  2000年   117篇
  1999年   91篇
  1998年   75篇
  1997年   55篇
  1996年   69篇
  1995年   57篇
  1994年   46篇
  1993年   42篇
  1992年   80篇
  1991年   65篇
  1990年   52篇
  1989年   76篇
  1988年   75篇
  1987年   63篇
  1986年   44篇
  1985年   55篇
  1984年   28篇
  1983年   21篇
  1982年   25篇
  1981年   27篇
  1980年   27篇
  1979年   18篇
  1978年   17篇
  1977年   16篇
  1976年   17篇
  1974年   9篇
  1973年   8篇
排序方式: 共有3210条查询结果,搜索用时 15 毫秒
1.
2.
Beta-blockers are among the most widely used antihypertensive drugs. They differ from each other in regard to several factors such as: beta-agonist activity, beta 1-selectivity and solubility. Aim of this work was to evaluate the influence of obesity on the kinetics and the antihypertensive effect of two Beta-blockers with different solubility such as: the water-soluble, atenolol and the liposoluble, metoprolol. The study was carried out according to an open randomized cross-over design. Eight obese hypertensive patients, after a two week washout period, were randomly allocated to a four week treatment. After a two week intermediate washout period, each patient switched to the other treatment for an additional four week period. On the first and the last day of each treatment the subjects were hospitalized to collect blood samples for the assay of the two drugs and to measure cardiovascular parameters. Obesity does not exert any effect on the kinetics of the water-soluble beta-blocker, atenolol, while markedly interferes with that of the liposoluble, without any apparent influence on its anti-hypertensive effect. These findings extend to obese hypertensives the concept that the plasma concentrations of beta-blocking agents are not reliable predictors of their therapeutic effect.  相似文献   
3.
4.
5.
Coronary artery bypass grafts: visualization with MR imaging   总被引:1,自引:0,他引:1  
Gomes  AS; Lois  JF; Drinkwater  DC  Jr; Corday  SR 《Radiology》1987,162(1):175
  相似文献   
6.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.  相似文献   
7.
8.
9.
BACKGROUND: Merkel cell carcinoma is a rare malignant neuroendocrine neoplasm characteristically arising from the dermis of sunlight-exposed skin. It rarely arises outside the skin. OBJECTIVE: We present a patient with primary Merkel cell carcinoma arising from subcutaneous fat, with no involvement of the overlying skin. We describe the clinical manifestations and magnetic resonance imaging (MRI) findings. METHODS: We report a 63-year-old woman with a primary lesion of Merkel cell carcinoma that arose from the subcutaneous fat layer of the left arm. The lesion presented as a subcutaneous nodule with intact overlying skin. MRI showed that the nodular lesion was located entirely in the subcutaneous fat layer, with no involvement of the dermis. Peritumoral infiltration around the lesion and enlarged lymph nodes deep to the lesion were noted. The patient received wide excision of the lesion with dissection of the regional lymph nodes and adjuvant radiotherapy and chemotherapy. RESULTS: Histopathologic examination confirmed the diagnosis of Merkel cell carcinoma with local lymphatic metastasis, and the lesion was completely located in the subcutaneous fat, with no involvement of the dermis. These findings were well correlated with MRI findings. CONCLUSION: Primary Merkel cell carcinoma may arise from the subcutaneous fat and present as an entirely subcutaneous lesion with intact skin. MRI is helpful to evaluate the local extension of the lesion and regional lymphatic metastasis.  相似文献   
10.
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