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   18457篇
  免费   1751篇
  国内免费   40篇
耳鼻咽喉   239篇
儿科学   558篇
妇产科学   395篇
基础医学   2245篇
口腔科学   376篇
临床医学   2450篇
内科学   3550篇
皮肤病学   208篇
神经病学   1392篇
特种医学   822篇
外国民族医学   3篇
外科学   2419篇
综合类   476篇
一般理论   9篇
预防医学   2010篇
眼科学   597篇
药学   1511篇
中国医学   15篇
肿瘤学   973篇
  2021年   313篇
  2020年   205篇
  2019年   302篇
  2018年   329篇
  2017年   209篇
  2016年   291篇
  2015年   308篇
  2014年   408篇
  2013年   594篇
  2012年   802篇
  2011年   869篇
  2010年   497篇
  2009年   425篇
  2008年   735篇
  2007年   834篇
  2006年   849篇
  2005年   780篇
  2004年   774篇
  2003年   693篇
  2002年   652篇
  2001年   570篇
  2000年   602篇
  1999年   531篇
  1998年   240篇
  1997年   219篇
  1996年   212篇
  1995年   209篇
  1994年   185篇
  1993年   166篇
  1992年   412篇
  1991年   416篇
  1990年   387篇
  1989年   411篇
  1988年   360篇
  1987年   337篇
  1986年   344篇
  1985年   325篇
  1984年   268篇
  1983年   229篇
  1982年   162篇
  1981年   125篇
  1979年   194篇
  1978年   170篇
  1977年   142篇
  1976年   130篇
  1975年   114篇
  1974年   160篇
  1973年   144篇
  1972年   129篇
  1971年   116篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
We here report a patient with an adenolipoma of the breast. The radiological features appeared to be characteristic. On mammography the mass was surrounded by a radiolucent ring and on ultrasonography the lesion was revealed as a well-defined, hypoechoic, lobulated and solid mass.  相似文献   
62.
63.
Catherine Jackson  Brian Lipworth 《Annals of allergy, asthma & immunology》2003,90(6):674; author reply 674-674; author reply 675
  相似文献   
64.
Peroneal nerve impalement is a recognized complication of percutaneous placement of wires, which is gaining increased usage with the application of the techniques of Ilizarov, Monticelli, and Spinelli. Dissections of the peroneal nerve in the proximal tibia were performed in ten anatomic specimens (20 legs) to define (1) its relationship to palpable landmarks, (2) distribution of major branches to the musculature, and (3) safe zones of placement of percutaneous wires in the proximal tibia. The anterior recurrent tibial nerve was frequently in an area of risk where it courses proximally in the anterior compartment. A safe zone is located anterior to the palpable portion of the fibular head and up to 2 cm distal to the tip of the fibular head.  相似文献   
65.
The frequency of metaphases without a Philadelphia chromosome was determined in mitogen-stimulated cultures of peripheral blood mononuclear cells (PBMC) and purified T lymphocytes (93% CD2-positive) from a patient with chronic myelogenous leukemia (CML) for 28 years. The PBMC cultures contained few Ph-negative cells (8%), but they constituted 92% of the metaphases in T cell cultures, indicating few if any Ph-positive T cells in the patient's circulation. The results demonstrate that T cells derived from the leukemic clone may fail to replace the non-neoplastic population even when CML arises in childhood and the patient survives for many years. This raises questions concerning the normal role of the bone marrow as a source of T cells after infancy, and also whether Ph-positive lymphocytes may be at a disadvantage for growth.  相似文献   
66.
Factors associated with hypertension in Nigerian civil servants   总被引:3,自引:0,他引:3  
BACKGROUND. Study of hypertension in segments of West African populations in transition toward Westernization may lead to better understanding of the high risk for hypertension among Westernized blacks. METHODS. Five hundred fifty-nine urban civil servants, ages 25-54, were recruited from six ministries of Bendel State, Nigeria. Blood pressure, physical measurements, urinary protein and glucose, fasting blood glucose, and demographic data were collected at the workplace. Subjects were classified as senior staff (professionals or administrators) or junior staff (non-administrators). RESULTS. Among 172 male senior staff, the age-adjusted rate of hypertension (diastolic blood pressure > or = 90 mm Hg, systolic blood pressure > or = 140 mm Hg, or on an antihypertensive medication) was 43% and occurrence rose dramatically from 21 to 63% across age groups 25-34 to 45-54, respectively. Among 266 male junior staff, the age-adjusted rate of hypertension was 23%, and occurrence did not rise with age. Logistic regression showed that body mass index (kg/m2), age, alcohol drinking, and being senior staff were all independently related to hypertension in men. On the other hand, the age-adjusted rate of hypertension in 121 women was 20% and was significantly related only to body mass index. CONCLUSION. Male urban civil servants appeared to have a risk for hypertension similar to that of U.S. black males. Age, body mass index, alcohol drinking, and other unidentified factors related to higher socioeconomic status were strong determinants of hypertension in this population.  相似文献   
67.
We reviewed the charts of 39 patients (45 eyes) with uveitis who underwent cataract extraction (intracapsular or extracapsular) with or without implantation of a posterior chamber intraocular lens (IOL) at the Royal Victoria Hospital, Montreal, between 1981 and 1990. The nine eyes with Fuchs' iridocyclitis in which an IOL was implanted had good visual results and few postoperative complications. The 18 eyes with uveitis other than Fuchs' iridocyclitis that received an IOL did not show a greater risk of postoperative complications than those left aphakic (n = 17), and the postoperative visual acuity was comparable to that of the aphakic eyes. Although the numbers are small, we conclude that the presence of uveitis does not automatically exclude posterior chamber pseudophakia.  相似文献   
68.
69.
Hypertensive emergencies are now rare and are recognized by the deleterious effect on end-organs. Prompt, efficacious treatment is critical, and the current drug of choice for most episodes is sodium nitroprusside. Hypertensive urgencies are more common than are emergencies, and are distinguished by diastolic pressures greater than 115 mm Hg without end-organ dysfunction. Although there are many efficacious agents, one excellent choice is nifedipine.  相似文献   
70.
Platelet utilization in a university hospital   总被引:3,自引:0,他引:3  
Two hundred forty-three patients received 22,717 U of platelets in our hospital during a three-month period. Those with hematologic diseases accounted for 43% of the patients but used 86% of the platelets. Sixty-eight percent of the transfusions were given to prevent bleeding and 32% were given to treat active bleeding. Ninety-two percent of therapeutic transfusions but only 22% of prophylactic transfusions met guidelines established by the Transfusion Therapeutics Committee of the University of Minnesota Hospital and Clinics, Minneapolis. However, 78% of prophylactic platelet transfusions that did not meet the guidelines involved patients with at least one clinical factor that their physicians believed placed them at an increased risk of bleeding. Following this analysis, the guidelines were modified and applied prospectively to requests for platelets. This resulted in a 14% decrease in the number of platelet units used during the following year. We conclude that published recommendations for platelet transfusions do not reflect the complex nature of many patients' conditions and that the use of guidelines developed by the medical staff can alter the use of platelet transfusions.  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