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   1657780篇
  免费   119578篇
  国内免费   7497篇
耳鼻咽喉   23271篇
儿科学   49798篇
妇产科学   47277篇
基础医学   239032篇
口腔科学   47078篇
临床医学   141177篇
内科学   326803篇
皮肤病学   34738篇
神经病学   125737篇
特种医学   64464篇
外国民族医学   475篇
外科学   256492篇
综合类   42611篇
现状与发展   9篇
一般理论   356篇
预防医学   111128篇
眼科学   38908篇
药学   130474篇
  45篇
中国医学   7071篇
肿瘤学   97911篇
  2018年   17412篇
  2017年   13315篇
  2016年   14626篇
  2015年   17411篇
  2014年   23786篇
  2013年   33250篇
  2012年   46346篇
  2011年   49078篇
  2010年   29308篇
  2009年   27342篇
  2008年   45884篇
  2007年   49561篇
  2006年   49728篇
  2005年   48126篇
  2004年   45615篇
  2003年   44304篇
  2002年   43355篇
  2001年   83173篇
  2000年   85228篇
  1999年   72087篇
  1998年   19325篇
  1997年   17133篇
  1996年   16851篇
  1995年   15758篇
  1994年   14783篇
  1993年   13537篇
  1992年   55542篇
  1991年   53740篇
  1990年   52666篇
  1989年   51390篇
  1988年   47470篇
  1987年   46274篇
  1986年   43797篇
  1985年   41528篇
  1984年   30194篇
  1983年   25917篇
  1982年   14771篇
  1981年   12913篇
  1979年   27628篇
  1978年   18911篇
  1977年   16453篇
  1976年   15005篇
  1975年   16647篇
  1974年   19469篇
  1973年   18709篇
  1972年   17921篇
  1971年   16806篇
  1970年   15562篇
  1969年   15082篇
  1968年   14076篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
961.
962.
963.
With the increased use of indwelling central venous catheters, increasing numbers of cases of Rhodotorula fungemia have been observed in patients with neoplasia and neutropenia. In most patients with catheter-related Rhodotorula fungemia, the condition has been treated with broadspectrum antibiotics. We report two cases of central venous catheter-related Rhodotorula rubra fungemia that occurred in patients with acute myeloblastic leukemia. Both patients were in a state of neutropenia. One patient was treated with amphotericin B and his central venous catheter was removed, but he died of Klebsiella pneumoniae bacteremia. The other patient was treated with amphotericin B and discharged, with a central venous catheter, after recovery from neutropenia. Although the management of catheter-related Rhodotorula fungemia infections remains controversial, resolution of the underlying disease is more important than catheter removal for recovery from Rhodotorula rubra fungemia. Received: August 22, 2001 / Accepted: October 8, 2001  相似文献   
964.
Adenoviruses are commonly used as vectors in human clinical gene therapy trials. High doses of intravenous adenovirus vectors have been associated with development of thrombocytopenia of undetermined origin. Viral internalization requires the presence cell surface integrins, alpha(v)beta(3) or alpha(v)beta(5), that can blind ligands with a arginine-glycine-aspartic acid (RGD) sequence. This sequence is found in the adenovirus penton base. Platelets express the alpha(v)beta(3) integrin and other integrins that bind the RGD sequence of ligands such as fibrinogen, laminin, vitronectin, and von Willebrand factor (vWF). Platelet aggregation is mediated, in part, by the binding of the RGD sequence of fibrinogen to a platelet surface integrin, glycoprotein IIb/IIIa (GP IIb/IIIa). We investigated whether adenovirus particles could interfere with or potentiate agonist-induced platelet aggregation. Incubation of platelet-rich plasma with adenovirus under stirred conditions did not promote spontaneous aggregation. The addition of physiological platelet agonists, ADP, collagen, or epinephrine, induced platelet aggregation. However, the presence of adenovirus in a wide range of concentrations did not inhibit or potentiate agonist-induced aggregation. These results suggest that the adenovirus-associated thrombocytopenia observed in vivo is independent of a direct effect of the virus on platelet aggregation.  相似文献   
965.
966.
BACKGROUND: The efficacy of nasal continuous positive airway pressure (nCPAP) as a prophylactic method for preventing cardiopulmonary complications after major vascular surgery has not been investigated. PATIENTS/METHODS: In a prospective randomized trial, 204 patients undergoing elective midline laparotomy for vascular surgery were randomized to receive standard therapy ( n=105) or additional prophylactic nCPAP ( n=99) for the first postoperative night. Postoperative oxygenation, incidence of severe cardiac, and pulmonary complications, length of intensive care surveillance and length of total postoperative hospital stay (LOS) were compared. RESULTS: Prophylactic nCPAP significantly reduced the number of patients with severe oxygenation disturbances defined as paO(2) < 70 mmHg with FiO(2) > or = 0.7 (5 versus 17, P=.01). There were no differences with respect to death, cardiac and pulmonary complications, length of intensive care surveillance or LOS. CONCLUSION: Prophylactic 12 h nCPAP significantly reduces the occurrence of postoperative oxygenation disturbances but has no effect on cardiac or pulmonary complications, need for intensive care, LOS or mortality after major vascular surgery.  相似文献   
967.
Out of 36511 patients attending the ENT OHD of R. G,. Aur Medical Callege & Hospital. Kolkata, in one year 0.08% patients were found tuning naspharyngeal mass. 30 cases of nasopharyngeal mass were studied. The peak incidence of nasopharyngeal mass was in the age group between II to 20 years (40%). The incidence in males (73%) was more than females(27%). The maximum ineldence was found among students (74%). Commonest ntuopharyngeal nuns teas antrochoanal polyp (30%). Next commlon masses were adenoids (23%)Juvenile angwfibroma(20%) and nasophartngeal carcinoma (13%). Nasal obstruction was the main presenting symptom(83%) followed by epistaxis (40%).  相似文献   
968.
Interest in inguinal hernia surgery has increased significantly with the introduction of new operating techniques during the past decade. This multicenter study compared short-term results in patients treated by the laparoscopic transabdominal preperitoneal patch technique (TAPP; n=518) and the Shouldice technique (n=524). We evaluated demographics, operative data, complications, hospital stay, postoperative pain, use of analgesics, functional status, sick leave, and complaints up to 3 months postoperatively. The median operating time was shorter in the Shouldice group (55 vs. 65 min), but there were no significant differences in complication rates, and major complications were rare. The hospital stay was 1 day or less in over 98% of cases in both groups, but more operations were performed on outpatient basis in the Shouldice group. In the TAPP group postoperative pain and analgesic consumption were less, postoperative functional status was better, and sick leave was shorter (10 vs. 14 days). These results show that the two methods are equally safe and have few major complications. The TAPP operation is associated with less postoperative pain, better postoperative functional status, and shorter sick leave, but at the price of a longer operating time. Electronic Publication  相似文献   
969.

Background  

Mycoplasma fermentans has been associated with rheumatoid arthritis. Recently, it was detected in the joints and blood of patients with rheumatoid arthritis, but it is not clear yet how the bacteria enter the body and reach the joints. The purpose of this study was to determine the ability of M. fermentans to induce experimental arthritis in rabbits following inoculation of the bacteria in the trachea and knee joints.  相似文献   
970.
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