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   674篇
  免费   31篇
  国内免费   5篇
耳鼻咽喉   3篇
儿科学   34篇
妇产科学   8篇
基础医学   61篇
口腔科学   16篇
临床医学   91篇
内科学   154篇
皮肤病学   32篇
神经病学   15篇
特种医学   124篇
外科学   58篇
综合类   26篇
预防医学   23篇
眼科学   4篇
药学   33篇
  1篇
肿瘤学   27篇
  2023年   1篇
  2022年   3篇
  2021年   3篇
  2020年   2篇
  2019年   4篇
  2018年   8篇
  2017年   3篇
  2016年   8篇
  2015年   10篇
  2014年   11篇
  2013年   15篇
  2012年   4篇
  2011年   11篇
  2010年   28篇
  2009年   32篇
  2008年   18篇
  2007年   30篇
  2006年   31篇
  2005年   27篇
  2004年   15篇
  2003年   10篇
  2002年   10篇
  2001年   16篇
  2000年   12篇
  1999年   9篇
  1998年   40篇
  1997年   45篇
  1996年   38篇
  1995年   19篇
  1994年   30篇
  1993年   23篇
  1992年   14篇
  1991年   11篇
  1990年   13篇
  1989年   28篇
  1988年   24篇
  1987年   11篇
  1986年   12篇
  1985年   6篇
  1984年   17篇
  1983年   17篇
  1982年   12篇
  1981年   11篇
  1980年   7篇
  1979年   1篇
  1978年   3篇
  1977年   2篇
  1976年   4篇
  1969年   1篇
排序方式: 共有710条查询结果,搜索用时 15 毫秒
41.
Coronary artery disease remains the major cause of perioperative mortality after abdominal aortic aneurysm (AAA) repair. The beneficial effect of coronary artery bypass (CAB) before AAA repair in patients with severe coronary artery disease has been proven. The coexistence of a very large or symptomatic AAA and coronary artery disease remains a therapeutic challenge since there is the risk of AAA rupture in the interval between CAB and AAA repair. Combined CAB and aortic aneurysm repair has been suggested for these cases, and results on several series of patients have been published. However, the exact indication for the combined operation remains to be clarified. We present a series of 13 patients who underwent CAB on cardiopulmonary bypass and aortic aneurysm repair as a one-stage procedure. The indication was a large AAA in seven patients and a symptomatic AAA in six patients. In four patients, the aortic reconstruction was performed without the use of cardiopulmonary bypass; in nine patients, the aortic reconstruction was performed under partial cardiopulmonary bypass. Thirty-day mortality was 15%. Major morbidity was 31%. All major complications were due to excessive bleeding and occurred in patients who had AAA repair performed with partial cardiopulmonary bypass, suggesting that prolonged bypass time represents a major source of morbidity. A detailed review of the literature is presented. From the evidence available we suggest that the combined procedure can be recommended only for patients with very high rupture risk, such as in symptomatic AAA. In all other cases, the staged approach — CAB followed by AAA repair 2-4 weeks later — is preferable. During the combined procedure, cardiopulmonary bypass support during AAA repair should be used only in patients with clear evidence of hemodynamic instability.  相似文献   
42.
Human T-cell lymphotropic virus I (HTLV-I)-induced adult T-cell leukemia (ATL) cells constitutively express interleukin-2 (IL-2) receptors identified by the anti-Tac monoclonal antibody (MoAb), whereas normal resting cells do not. This observation provided the scientific basis for a trial of intravenous anti-Tac in the treatment of nine patients with ATL. The patients did not suffer untoward reactions and did not have a reduction in the normal formed elements of the blood, and only one of the nine produced antibodies to the anti-Tac MoAb. Three patients had transient mixed, partial, or complete remissions lasting from 1 to more than 8 months after anti-Tac therapy, as assessed by routine hematologic tests, immunofluorescence analysis of circulating cells, and molecular genetic analysis of HTLV-I provirus integration and of the T-cell receptor gene rearrangement. The precise mechanism of the antitumor effects is unclear; however, the use of a MoAb that prevents the interaction of IL-2 with its receptor on ATL cells provides a rational approach for the treatment of this malignancy.  相似文献   
43.
<正>背景:该研究旨在评价在现有的冠状动脉粥样硬化的病变中,遗传因素对粥样硬化斑块进展及特异性心肌梗死是否存在显著作用。方法:对欧洲后裔参与者冠状动脉造影表型进行了两项全基因组关联研究(GWAS),为寻找冠状动脉疾病(CAD)易感性基因位点,研究比较了有异常(n=12393)和无异常的(对照组n=7383)个体;为寻找心肌梗死易感性基因位点,也同时比较了造影证实存在CAD并且有心肌梗死的个体(n=5783)与虽有CAD但无心肌梗死的个体(n=3644)。  相似文献   
44.
Background Some adnexal tumours have many controversies about their histogenesis. Objectives To evaluate the eccrine and/or apocrine differentiation phenotype in cases of cylindroma and clear cell hidradenoma with CD15 and p63 antibodies. Methodology Slides and blocks of six cases of cylindroma and seven cases of nodular hidradenoma (clear cells) were analyzed by the technique of immunohistochemistry with CD15 and p63 antibodies. Results In all cases of cylindroma we obtained negative results for CD15 antibody and positive for p63 antibody. In five of seven cases of nodular hidradenoma (clear cell), we could easily observe clear cells between 20% and 50% of tumour cells. In the two other cases, cystic lesions were present and occasional clear cells could be seen. The reaction with CD15 antibody was positive in granular and cytoplasmic pattern in six of seven cases, especially in cells with suggestive clear cytoplasm in lower proportion than this clear cells could be seen in haematoxylin and eosin. The positivity for p63 antibody, nuclear pattern, was observed in six of seven cases, in the major part of tumour cells. In only one case, the positivity was in 20% of cells. Limitation Samples are in small number because these are relatively rare tumours. Conclusions The present study suggests eccrine origin for both tumours: cylindroma and clear cell hidradenoma.  相似文献   
45.
46.
47.
Transient evoked otoacoustic emissions (TEOAEs) are low amplitude sound waves produced by the healthy cochlea. They can be recorded with a microphone in the external ear. TEOAEs are abolished by hearing losses of 30 dB or more. The feasibility of using TEOAEs as a screening test for hearing loss in children was studied. TEOAE recordings were attempted in 56 children attending an audiology clinic. Recordings were possible from both ears in 52 children; of these 104 ears, 32 had hearing deficits of 30 dB or more. Hearing status was compared with the results of six TEOAE screening criteria. All criteria had a sensitivity of 1.00. Four standard TEOAE criteria yielded specificities of 0.46-0.58. Two new criteria derived from analysis of limited frequencies from the TEOAE waveform gave specificities of 0.76 and 0.82. It can be concluded that, when appropriate pass/fail criteria are employed, TEOAEs are a feasible screening test in children.  相似文献   
48.
49.
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