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   2114篇
  免费   141篇
  国内免费   5篇
耳鼻咽喉   65篇
儿科学   125篇
妇产科学   344篇
基础医学   182篇
口腔科学   86篇
临床医学   204篇
内科学   380篇
皮肤病学   24篇
神经病学   84篇
特种医学   51篇
外科学   239篇
综合类   33篇
一般理论   2篇
预防医学   195篇
眼科学   58篇
药学   94篇
中国医学   1篇
肿瘤学   93篇
  2022年   15篇
  2021年   25篇
  2020年   15篇
  2018年   30篇
  2017年   15篇
  2016年   22篇
  2015年   23篇
  2014年   41篇
  2013年   54篇
  2012年   89篇
  2011年   76篇
  2010年   58篇
  2009年   41篇
  2008年   83篇
  2007年   97篇
  2006年   118篇
  2005年   120篇
  2004年   98篇
  2003年   97篇
  2002年   64篇
  2001年   71篇
  2000年   65篇
  1999年   63篇
  1997年   19篇
  1996年   14篇
  1995年   22篇
  1994年   12篇
  1993年   13篇
  1992年   47篇
  1991年   45篇
  1990年   55篇
  1989年   41篇
  1988年   48篇
  1987年   50篇
  1986年   47篇
  1985年   56篇
  1984年   45篇
  1983年   30篇
  1982年   26篇
  1981年   25篇
  1980年   21篇
  1979年   31篇
  1978年   22篇
  1977年   17篇
  1976年   17篇
  1975年   15篇
  1974年   18篇
  1971年   17篇
  1970年   15篇
  1969年   11篇
排序方式: 共有2260条查询结果,搜索用时 15 毫秒
1.
2.
After recently meeting with his biological parents, the author--a 29-year-old-married male--learned he had been an hour away from being aborted, being 'saved' only by extraordinary circumstances. In the paper the author reflects upon previous strong pro-choice beliefs and reasserts his commitment to a pro-choice philosophy, integrating his new personal experience. The paper pays particular attention to the biological mother's experience and how her fresh insights have reinforced the author's views on abortion.  相似文献   
3.
H D Berkowitz  A D Fox  D H Deaton 《Journal of vascular surgery》1992,15(1):130-41; discussion 141-2
Conscientious surveillance of intrainguinal bypass grafts is mandatory to detect vein graft stenoses, which, if uncorrected, can lead to graft occlusion. It is now widely accepted that noninvasive vascular laboratory studies are the best way to detect these lesions. However, controversy still exists over treatment, specifically whether balloon angioplasty is an acceptable substitute for surgery (patch angioplasty or short jump grafts) in the treatment of these lesions. We have always favored balloon angioplasty as primary treatment and have summarized our experience with treating 72 stenotic reversed femoropopliteal and femorotibial vein grafts, which represent 12% of 521 bypass grafts performed at our institution. Prosthetic and in situ grafts are specifically excluded from this report, as well as occluded grafts, found to have stenotic lesions after lytic therapy. The most common stenotic lesion occurred within 4 cm of the proximal anastomosis (29/72 = 40%). The other sites were near the distal anastomosis (7/72 = 10%), and in the middle of the graft (15/72 = 12%). Eighty-one percent (58/72) of the lesions were treated initially by balloon angioplasty with a 31% recurrence. Twenty-nine percent of the 14 grafts treated surgically by vein patch angioplasty or short jump grafts experienced recurrence. Overall 61% (44/72) of the stenotic grafts were treated by balloon angioplasty alone. The 5-year life-table assisted primary patency after correction of the stenotic lesion was 61%. The patency of the grafts from the time of initial bypass surgery, however, was 80%. Location of the stenosis within the graft was a major determinant of patency. Lesions in the proximal graft, proximal anastomosis, and distal graft taken as a group had significantly better patency than the midgraft and distal anastomotic lesions (5-year patency, 65% vs 48%, p less than 0.001 log rank test). We continue to recommend balloon angioplasty as primary therapy for vein graft stenosis except for those occurring in the midgraft and distal anastomosis. Fortunately, this group accounts for only 36% of lesions seen with reversed veins. Recurrent stenosis after balloon angioplasty should be repaired surgically.  相似文献   
4.
5.
BACKGROUND AND OBJECTIVE: The adverse effects of untreated seasonal allergic rhinitis (AR) on performance in the workplace, school, and home are poorly understood. To delineate more clearly the impact and consequences of the disease on performance, the effect of symptomatic AR on vigilance and a wide range of cognitive functions was investigated. METHODS: A battery of automated neuropsychological tests was administered to asymptomatic adult subjects with histories of AR. Subjects were randomized to either a symptomatic or to an asymptomatic group. Subjects in the symptomatic group were exposed to ragweed pollen in a controlled exposure setting until they demonstrated predetermined severities of AR symptoms. Subjects in the asymptomatic group were not exposed to ragweed pollen in the environmental unit and retained a minimum symptom profile. The battery of cognitive measures was re-administered to both groups. RESULTS: AR had major adverse impacts on measures of vigilance. Further, AR adversely affected a broad range of cognitive functions. Specifically, subjects with AR symptoms demonstrated longer response times and decreased efficiency on measures of working memory, psychomotor speed, reasoning/computation, and divided attention as compared with asymptomatic subjects. CONCLUSIONS: In addition to decreased vigilance, AR was associated with decrements in speed and efficiency across several cognitive domains. This is similar to findings in research on medications and medical conditions that cause sedation. Findings may represent a link between AR and poor productivity/personal safety among AR sufferers. This suggests that these results have implications with regard to public health.  相似文献   
6.
The sequence of rat hypothalamic pro-thyrotropin releasing hormone, deduced by sequencing of cDNA, in addition to 5 TRH progenitor genitor sequences contains leader, trailer and 4 intervening sequences separated by paired basic amino acid sequences. We have developed radioimmunoassays to synthetic peptides corresponding to portions of these cryptic proTRH sequences and have used these assays to identify and partially characterize proTRH peptides, distinct from TRH, in extracts of rat brain. Two of these peptides correspond closely in size to one intervening sequence and the car☐y-terminal sequence of proTRH. Three other peptides correspond to the intact amino-terminal leader sequence and two peptides formed by a further cleavage of the leader sequence at an internal paired basic amino acid sequence.  相似文献   
7.
8.
Administration of antiserum to thyrotropin-releasing hormone (TRH) into the lateral cerebral ventricle of mice significantly attenuated recovery from hyperglycemia induced by treatment with 2-deoxyglucose but had no effect on the plasma glucose of saline-treated mice. TRH, injected centrally together with the anti-TRH antibody, reversed the effect of the antiserum and blocked the development of hyperglycemia. These findings suggest that activation of TRH neurons in the central nervous system may be a physiological event influencing recovery from hyperglycemia.  相似文献   
9.
Dear Professor Lian-Sheng Ma, Professor Michael Hobsley and I have greatly enjoyed reading the account of all you have done towards the development of "The World Journal of Gastroenterology", as described in the article by Zhen-Xi Li in the November 21st. Issue of the Journal.  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