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   18277篇
  免费   779篇
  国内免费   133篇
耳鼻咽喉   219篇
儿科学   413篇
妇产科学   327篇
基础医学   2399篇
口腔科学   405篇
临床医学   1031篇
内科学   4990篇
皮肤病学   350篇
神经病学   1044篇
特种医学   750篇
外科学   2991篇
综合类   59篇
一般理论   4篇
预防医学   414篇
眼科学   312篇
药学   1350篇
中国医学   52篇
肿瘤学   2079篇
  2023年   74篇
  2022年   135篇
  2021年   244篇
  2020年   143篇
  2019年   196篇
  2018年   255篇
  2017年   216篇
  2016年   294篇
  2015年   302篇
  2014年   362篇
  2013年   525篇
  2012年   823篇
  2011年   893篇
  2010年   549篇
  2009年   458篇
  2008年   852篇
  2007年   1003篇
  2006年   1047篇
  2005年   1002篇
  2004年   990篇
  2003年   993篇
  2002年   1038篇
  2001年   499篇
  2000年   516篇
  1999年   496篇
  1998年   273篇
  1997年   216篇
  1996年   188篇
  1995年   148篇
  1994年   145篇
  1993年   163篇
  1992年   410篇
  1991年   363篇
  1990年   316篇
  1989年   343篇
  1988年   263篇
  1987年   258篇
  1986年   265篇
  1985年   305篇
  1984年   152篇
  1983年   145篇
  1982年   93篇
  1981年   78篇
  1979年   111篇
  1978年   98篇
  1977年   83篇
  1969年   84篇
  1968年   92篇
  1967年   67篇
  1966年   85篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Ten patients underwent repair of aneurysms of the distal aortic arch from 1985 to 1989. There were 8 men and 2 women: aged 58 to 77 (average age 67 years). Seven patients had sacciform aneurysms which were closed by graft patch aortoplasty, and three patients had fusiform aneurysms which were corrected by inserting tube grafts. Seven aneurysms operated since 1988 were approached through median sternotomy continued with left anterior thoracotomy, so called door open method. This approach presented good view of the diseased aorta, and effective for preventing recurrent and phrenic nerve palsy. We used temporary bypass for 4 patients, cardiopulmonary bypass for 4 patients (separate carotid artery perfusion for 2 patients) and centrifugal pump for 2 patients during aortic cross clamping. One patient died intraoperatively from intractable bleeding and two patients died postoperatively from brain damage due to embolic episodes during the operations. These patients showed the severely irregular intima in the aortic arch and were complicated with rupture of the aneurysm or dissections arising from the aneurysms. It should be noticed that careless manipulation of the aortic arch and the brachiocephalic vessels cause cerebral complications in such cases.  相似文献   
993.
Three statis growers complaining of immediate allergic symptoms induced by harvesting statis in a plastic greenhouse were examined to clarify their allergic conditions. Distinct positive reactions in the intradermal test and nasal and eye provocation test to the statis extracts were shown in all three cases. High score of radioallergosorbent test (RAST) IgE and remarkable RAST inhibitory effects to the statis extracts were seen in these cases. The immunologic cross-reactivity between statis and chrysanthemum was absent in the RAST inhibition in the patient labeled case C who had complained of the same allergic symptoms when handling chrysanthemums in the off-season for harvesting statis. Those results indicated that the allergic conditions of the present cases were from an immediate type of allergy mediated by a specific IgE antibody to the statis extract.  相似文献   
994.
995.
996.
The supracommissural ventral telencephalon and the medial preoptic area have been shown to play important roles in the sexual behavior of hime´salmon (landlocked red salamon,Oncorhynchus nerka). In the present study, the sites of neurons projecting to these regions were examined by means of the retrograde horseradish peroxidase (HRP) tracing method. The morphology of neurons in these sites of origin was also studied by means of the Golgi method. The nucleus preopticus periventricularis and the rostral part of nucleus preopticus (NPP-rNPO) received bilateral projections from the middle parts of the area ventralis telencephali pars ventralis (Vv) and the area ventralis telencephali pars dorsalis (Vd), NPP and lateral part of the preoptic area (LPOA), ipsilateral projections from the caulal part of Vv, nucleus anteriors periventricularis (NAPv), nucleus ventromedialis thalami (NVM) at the level of the posterior commissure, nucleus lateralis tuberis pars medialis (NLTm), nucleus anterior tuberis (NAT), nucleus saccus vasculosus (NSV), nucleus recessus posterioris (NRP) and midbrain tegmentum (TG), and a projection from the nucleus posterior tuberis (NPT), which is situated on the midline of the brain. The area ventralis telencephali pars supracommissuralis and neighboring caudal ventral telencephalon (Vs-cV) received ipsilateral projections from almost all parts of the Vv, the middle and caudal parts of Vd, almost all parts of the NNP, the NPO at the level between the habenula and the posterior commisure, and the rostral part of the nucleus dorsomedialis thalami (NDM). The Vs-cV also received a projection from NPT. These findings seem to give anatomical bases for understanding the neural mechanisms involved in sexual behavior as well as neuroendocrine functions.  相似文献   
997.
The present study investigated the effects of the NMDA receptor antagonists dizocilpine (MK-801) and ifenprodil on the appearance of diazepam withdrawal signs caused by discontinuation of long-term diazepam treatment using a drug-admixed food (DAF) method in Fischer 344 rats. The total withdrawal score was significantly decreased by after-withdrawal treatment with dizocilpine or ifenprodil. Dizocilpine, in particular, markedly suppressed the motor withdrawal signs and body weight loss, while ifenprodil suppressed the motor and emotional withdrawal signs. Furthermore, the decrease in the food intake during withdrawal (anorexia) was significantly reduced by dizocilpine, but not by ifenprodil. These behavioral results indicated that the activation of NMDA receptors during withdrawal may play an important role in the appearance of withdrawal signs (in particular motor withdrawal signs) caused by discontinuation of chronic diazepam treatment, and that inhibitory agents for NMDA receptors may be effective in alleviation of the appearance of benzodiazepine withdrawal signs.  相似文献   
998.
Small Depressed Cancer of the Large Bowel: Report of Three Cases   总被引:2,自引:0,他引:2  
This report describes three patients in whom colonos-copy detected small depressed cancers (without an elevated component) that had invaded the submucosa. They represent 0.4% (3/884) of all patients with invasive cancers and 3% (3/101) of patients with submucosal cancers in the National Cancer Center Hospital between January 1990 and February 1994. This type of cancer may have been overlooked in the past because of its small, flat nature. A slight deformity of the lumen, a faint color change (slightly reddish), and a loss of a vascular network pattern were important colonoscopic findings. Small depressed cancers may follow a different pathway to advanced cancer than polypoid cancers, although both pathways are included in the adenoma-carcinoma sequence. We should be aware of these lesions in our efforts to detect colorectal cancers in the early stage.  相似文献   
999.
An 8-month-old girl of anomalous origin of the left coronary artery from the pulmonary artery associated with severe mitral regurgitation underwent radical operation. She had been in serious cardiac and respiratory failure. Aorto-left coronary arterial continuity was established by intrapulmonary arterial tunnel using Takeuchi's technique. Mitral annulus was plicated by modified Kay's technique. Post-operative course was uneventful.  相似文献   
1000.
Sixteen patients with lymph nodes metastases and/or locally advanced bladder carcinoma were treated with a combination chemotherapy regimen consisting of methotrexate, vinblastine, adriamycin, and cisplatin (M-VAC) from November 1986 through September 1988. There were 14 men and 2 women. The median age was 61.9 years, with a range from 43 to 81 years. Complete response (CR) was observed in 6 of 16 patients (38%), partial response (PR) was confirmed in 5 of 16 patients (31%), and overall response rate was 69%. Median duration of response was 10.3 and 5.2 months in CR and PR patients, respectively. The myelosuppression with this regimen was tolerable. This study demonstrates that the M-VAC regimen is effective in the invasive bladder carcinoma with or without lymph nodes metastases. However, the duration of response is relatively short, and the true long-term benefits of this regimen remain to be determined.  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