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   2276篇
  免费   138篇
  国内免费   17篇
耳鼻咽喉   19篇
儿科学   80篇
妇产科学   28篇
基础医学   321篇
口腔科学   32篇
临床医学   253篇
内科学   556篇
皮肤病学   25篇
神经病学   207篇
特种医学   284篇
外科学   212篇
综合类   43篇
预防医学   148篇
眼科学   33篇
药学   92篇
  1篇
中国医学   11篇
肿瘤学   86篇
  2022年   13篇
  2021年   37篇
  2020年   12篇
  2019年   26篇
  2018年   27篇
  2017年   30篇
  2016年   27篇
  2015年   37篇
  2014年   38篇
  2013年   67篇
  2012年   99篇
  2011年   116篇
  2010年   78篇
  2009年   91篇
  2008年   106篇
  2007年   114篇
  2006年   99篇
  2005年   120篇
  2004年   83篇
  2003年   72篇
  2002年   89篇
  2001年   29篇
  2000年   46篇
  1999年   43篇
  1998年   57篇
  1997年   54篇
  1996年   43篇
  1995年   53篇
  1994年   44篇
  1993年   43篇
  1992年   27篇
  1991年   25篇
  1990年   28篇
  1989年   53篇
  1988年   38篇
  1987年   50篇
  1986年   59篇
  1985年   45篇
  1984年   31篇
  1983年   37篇
  1982年   19篇
  1981年   23篇
  1980年   26篇
  1979年   20篇
  1978年   20篇
  1977年   22篇
  1976年   20篇
  1975年   14篇
  1971年   9篇
  1968年   9篇
排序方式: 共有2431条查询结果,搜索用时 31 毫秒
1.
2.
3.
Chewing Gum Headaches   总被引:2,自引:0,他引:2  
Dr.  Harvey J. Blumenthal  MD  Dwight A. Vance  RPh 《Headache》1997,37(10):665-666
Aspartame, a popular dietetic sweetener, may provoke headache in some susceptible individuals. Herein, we describe three cases of young women with migraine who reported their headaches could be provoked by chewing sugarless gum containing aspartame.  相似文献   
4.
5.
The beStent is a new stainless steel, balloon-expandable mesh stent which has a unique serpentine design. Rotation of the unique low stress junctions upon expansion leads to orthogonal locking of the wires, maximizing radial strength and assuring zero shortening. The stent has delineating gold markers which assure precise positioning. We aim to present the initial acute results in a pilot registry for stent evaluation. Two hundred eighty-four stents were used in a total of 217 patients (age 57.9 ± 3.10 years; 178 males; 39 females) in seven centers, for variable indications. Stents of 15-, 25-, and 35-mm length were used. The arteries treated were the left anterior descending (n = 112, 42%), circumflex (n = 54, 20.2%), right coronary (n = 95, 35.5%), left main (n = 1, 0.4%), and vein graft (n = 5, 1.9%). Lesion types were: A in 42 patients (16.5%); B1 in 53 patients (20.7%); B2 in 81 patients (31.8%); and C in 79 patients (31%). One hundred fifty-nine patients required one stent, 40 patients required two stents, and 18 patients required three or more stents. Anticoagulation protocol included procedural heparin with aspirin with/without ticlopidine. Smooth angiographie results were obtained in all cases with no plaque herniation. Acute angiographic success was obtained in 97% of the patients, and acute clinical success in 95% of the patients. Complications within 30 days were: 3 deaths (1.4%) (2 noncardiac); 2 (0.9%) myocardial infarctions; and 2 (0.9%) stent thromboses. Therefore, the beStent is useful in treatment of complex lesions of variable length and complexity, providing excellent acute results with a low complication rate, in spite of unfavorable basic clinical and angiographie characteristics.  相似文献   
6.
7.
In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients.  相似文献   
8.
9.
10.
The alpha angle alpha (degrees) is a thrombelastographic measure of clot propagation. A parametric measurement of clot propagation [maximum rate of thrombus generation (MRTG), dynes/cm2 per s], however, has recently been utilized. Thus, the relationship of changes in alpha with changes in MRTG were determined. alpha and MRTG values obtained from 859 thrombelastograms was collected from nine studies. Data were analyzed and the relationship between alpha and MRTG defined with commercially available software. Additional comparisons were made retrospectively from whole-blood and plasma data obtained from 33 normal individuals. Data from the nine studies demonstrated that MRTG increased in an exponential fashion compared with increases in alpha (R2 = 0.88, P < 0.001). Whole-blood alpha values were in the range 66.7-74.7 whereas MRTG values were 5.5-10.8, and plasma alpha values were 65.1-77.9 with corresponding MRTG values of 3.5-12.0. Assessment of clot propagation utilizing MRTG provides a more parametric evaluation than the determination of alpha. While normal alpha values may vary by only 12-20%, MRTG values vary by approximately 200-300%. The MRTG should be progressively utilized to a greater extent in both laboratory and clinical settings to parametrically quantify clot growth kinetics with thrombelastography.  相似文献   
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