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   169853篇
  免费   6736篇
  国内免费   611篇
耳鼻咽喉   2226篇
儿科学   4838篇
妇产科学   4003篇
基础医学   24040篇
口腔科学   5558篇
临床医学   10000篇
内科学   36979篇
皮肤病学   4652篇
神经病学   13382篇
特种医学   4214篇
外国民族医学   1篇
外科学   19504篇
综合类   1888篇
一般理论   24篇
预防医学   20209篇
眼科学   4438篇
药学   13314篇
  5篇
中国医学   1098篇
肿瘤学   6827篇
  2023年   874篇
  2022年   803篇
  2021年   2816篇
  2020年   1592篇
  2019年   3069篇
  2018年   5066篇
  2017年   3189篇
  2016年   3167篇
  2015年   3600篇
  2014年   4108篇
  2013年   6153篇
  2012年   10499篇
  2011年   11056篇
  2010年   5670篇
  2009年   4301篇
  2008年   9039篇
  2007年   9707篇
  2006年   9263篇
  2005年   8827篇
  2004年   8140篇
  2003年   7604篇
  2002年   7214篇
  2001年   5015篇
  2000年   5548篇
  1999年   4239篇
  1998年   758篇
  1992年   2239篇
  1991年   1998篇
  1990年   1989篇
  1989年   1692篇
  1988年   1620篇
  1987年   1513篇
  1986年   1551篇
  1985年   1458篇
  1984年   1042篇
  1983年   898篇
  1979年   1207篇
  1978年   809篇
  1977年   780篇
  1976年   742篇
  1975年   877篇
  1974年   1121篇
  1973年   1165篇
  1972年   1111篇
  1971年   1078篇
  1970年   1011篇
  1969年   1084篇
  1968年   1106篇
  1967年   978篇
  1966年   878篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
To evaluate the effects of irradiation on heterotopically placed vascularized knee isografts, a single dose of 10 Gy of total-body irradiation was given to Lewis donor rats. Irradiation was delivered either 2 or 6 days prior to harvesting or subsequent transplantation, and evaluated at 1, 2, and 4 weeks after grafting. Irradiation caused endothelial depopulation of the graft artery, although vascular pedicle patency was maintained throughout the study. Bone graft viability and mineralization were normal. Dramatic changes in the bone marrow were seen that included an increase of its fat content (P less than 0.001), and a concomitant decrease in bone marrow-derived immunocompetent cells. These changes were more prominent in recipients of grafts from day -6 irradiated donor rats. Total-body irradiation did not prejudice the use of vascularized bone grafts, and exhibited an associated immunosuppresant effect over the vascular endothelium and bone marrow. This may be a further rational conditioning procedure to avoid recipient manipulation in vascularized bone allotransplantation.  相似文献   
102.
103.
104.
组织扩张术皮肤胶原的代谢改变   总被引:4,自引:0,他引:4  
李江  鲁开化 《医学争鸣》1998,19(3):307-309
目的:研究常规扩张(ITE)和持续快速扩张(CTE)对皮肤胶原代谢的影响。方法用白色小家猪制作组织扩张术动物模型,用Gordeladze法测定血清和扩张组织的羟脯氨酸(HP)含量,藻酸盐印模材膜片法测量标记区面积;光镜测量真皮厚度。结果:ITE组血清HP含量升高,0.8倍,CTE组升高1.2倍,ITE和CTE组皮肤含量与正常皮肤相同,组织中HP总量均明显升高,持续扩张皮瓣组(CTEF)术后4wk皮  相似文献   
105.
A total of 186 blood samples from 24 HIV-1 seropositive hemophiliac patients, monitored every four months for 29 months, were investigated for the presence of viral antigen in plasma. In addition, peripheral blood mononuclear cells (PBMC) were cultured for HIV-1, using normal PBMC as a target for replication. Antigenemia was detected in 51 % of the patients and from PBMC in 87.5 % of the patients. The incidence of HIV isolation in asymptomatic patients (42.8 %) was similar to that found in symptomatic patients (51.4 %). Patients with opportunistic infections had a higher incidence of lymphocytic viremia (p<0.05). Plasma viremia was closely associated (p<0.05) with low CD4+ counts and infection progression. The persistence of antigenemia was also a marker of a poor clinical course. In treated patients, plasma viremia was the marker that better correlated with the clinical course, and it did not appear during the first nine months of therapy. Zidovudine doses of >500 mg/day significantly lowered the appearance of antigenemia and lymphocytic viremia (p<0.05).  相似文献   
106.
Anatomic dissection of 220 cadaver shoulders was performed to find out more about the static stabilizers of the shoulder joint. The static stabilizers, i.e. the glenohumeral ligaments, were always found to be present and strong in healthy shoulders. It was revealed that in anatomic preparations with all the organs removal except the synovial capsule, the capsule ligaments completely stabilized the joint. Anterior dislocation at 45 degrees of abduction was prevented by the superior and medial glenohumeral ligaments, while at 90 degrees of abduction the inferior glenohumeral ligament prevented dislocation. When anterior dislocation has occurred even the coracohumeral ligament must be ruptured. A new finding recorded is that the glenoid labrum is the origin of the inferior glenohumeral ligament and not a triangular static organ enlarging the socket and having a similar function to the menisci in the knee. This ligament is the most important ventral stabilizer of the humeral joint. With the conventional arthrotomy technique the medial and inferior ligaments are immediately cut through and therefore cannot be seen. The inferior glenohumeral ligament must be reconstructed in cases of anterior recurrent dislocation.  相似文献   
107.
A series of N-(phosphonoacetyl)-dipeptide derivatives was synthesized for pharmacological testing as antihypertensive compounds. Several of these compounds demonstrated a moderate antihypertensive effect in Wistar spontaneous hypertensive rats (SHR) with p.o. dosing. ACE inhibition by the compounds was studied using ACE from rat plasma and lung. Inhibitors containing esterified C-termini are pro-drugs and showed activity only for plasma ACE.  相似文献   
108.
Authors describe a case of isolated posttraumatic neuropraxy of the musculocutaneous nerve. With the presentation of this very rare case attention is called, based on literary date, to the fact that the above injury can be mixed with the distal tendon rupture of the biceps.  相似文献   
109.
110.
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