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   24816篇
  免费   2488篇
  国内免费   48篇
耳鼻咽喉   225篇
儿科学   705篇
妇产科学   588篇
基础医学   3383篇
口腔科学   607篇
临床医学   2939篇
内科学   5147篇
皮肤病学   355篇
神经病学   2384篇
特种医学   823篇
外科学   3220篇
综合类   585篇
一般理论   15篇
预防医学   2558篇
眼科学   456篇
药学   2153篇
  1篇
中国医学   31篇
肿瘤学   1177篇
  2021年   362篇
  2019年   352篇
  2018年   409篇
  2017年   329篇
  2016年   314篇
  2015年   372篇
  2014年   519篇
  2013年   771篇
  2012年   1119篇
  2011年   1159篇
  2010年   669篇
  2009年   560篇
  2008年   1006篇
  2007年   1188篇
  2006年   1089篇
  2005年   1128篇
  2004年   1003篇
  2003年   1066篇
  2002年   955篇
  2001年   693篇
  2000年   692篇
  1999年   601篇
  1998年   297篇
  1997年   239篇
  1996年   220篇
  1995年   260篇
  1994年   239篇
  1993年   214篇
  1992年   525篇
  1991年   489篇
  1990年   463篇
  1989年   465篇
  1988年   427篇
  1987年   425篇
  1986年   378篇
  1985年   444篇
  1984年   378篇
  1983年   298篇
  1982年   290篇
  1981年   236篇
  1980年   243篇
  1979年   346篇
  1978年   302篇
  1977年   213篇
  1976年   248篇
  1975年   215篇
  1974年   272篇
  1973年   284篇
  1972年   232篇
  1971年   213篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Two experiments were conducted to assess the effects of chronic subcutaneous injections of morphine (1.0 mg/kg) or saline on the pattern and amount of sweetened ethanol and water intake in fluid restricted Long-Evans rats. Following daily injections, 2-h two-bottle choice tests were conducted with water and an ethanol solution (15% ethanol v/v in 5% sucrose w/v). During a 20-day acquisition phase (Experiment 1), ethanol intake patterns and amounts did not differ between saline (n = 6) and morphine (n = 6) groups. Both groups exhibited ethanol intake patterns that decreased exponentially throughout the session suggesting control by fluid restriction procedures. Morphine decreased water intake during initial periods of each session and increased intake during later periods. In Experiment 2, morphine and saline injections were reversed across three phases with the same rats. Morphine increased total ethanol consumption during the first few days of each 15-day phase, but the groups did not differ thereafter, and the initial increases produced no statistically significant group differences. Additionally, morphine augmented ethanol intake in early portions of sessions, while water intake was decreased and increased during early and later portions of each session, respectively. Analysis of the data from the last 5 days of each phase indicated that, when injected with morphine, the group which received saline during acquisition consumed significantly more ethanol solution than the group injected with morphine during acquisition. The effect on patterns of water and ethanol intake were observed, regardless of the drug injected during acquisition.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
43.
44.
45.
The development of implantable left ventricular assist devices (LVADs) has almost reached the stage of providing permanent circulatory support in patients who are unsuitable for, or denied, the transplant option. As part of our ongoing haemodynamic evaluation of the Thermo Cardiosystems Inc. (Boston, USA) Mark 14 pneumatic LVAD, pressure-volume loops have been produced from in vitro studies using a modified National Heart Lung and Blood Institute (NHLBI, USA) mock circulatory loop. These studies have demonstrated that during certain phases of the pump cycle non-physiologically high and low pressures are generated within the LVAD. Such abnormal pressures may damage either the bioprosthetic valves in the LVAD or the native heart, and may have adverse effects on cardiovascular control mechanisms.  相似文献   
46.
This article describes a specialized rehabilitation education program, based on adult learning theory, that was developed to promote retention of rehabilitation nurses at MetroHealth Center for Rehabilitation in Cleveland. The curriculum encompasses the skills required to care for rehabilitation patients needing both advanced rehabilitation nursing and critical care nursing. Critical care and rehabilitation nurses collaborated in the presentation of topics and were guided by the course coordinators. Learners were chosen based on experience in rehabilitation, with priority given to those certified in rehabilitation nursing. A variety of evaluation methods elicited positive responses. A 6-month postcourse survey also was completed to assess the long-term effects of the course.  相似文献   
47.
Summary In a study of 11 adult patients with acute nonlymphocytic leukemia (ANLL), infusion therapy with high-dose VP-16 and intermediate-dose cytosine arabinoside was administered. Response was assessed with reference to bone marrow aspirations performed on days 1; 12, 13, or 14; and 21 of treatment. All 7 of the patients with ANLL in relapse achieved marrow hypoplasia, and 3 of them achieved complete response. LFTs were elevated in most patients but no evidence of hepatocellular necrosis was observed. It is concluded that the value of VP-16 in ANLL may have been underestimated in the past because of inadequate dosing.Abbreviations ANLL acute nonlymphocytic leukemia - CGL chronic granulocytic leukemia - DNR daunorubicin - VNC vincristine - ID Ara-C, intermediate-dose Ara-C (500 mg/m2 for 12 doses) - HD Ara-C, high-dose Ara-C (3 g/m2 for 12 doses) - SGGT serum glutamic transaminase - LDH lactic dehydrogenase - SGOT serum glutamic oxaloacetic transaminase  相似文献   
48.
49.
Delayed hypersensitivity (DH) was induced in the footpads of mice sensitized to methylated bovine serum albumin (MBSA). The magnitude of this DH response increased with increasing sensitizing concentration of MBSA. Levamisole administered 1 hr prior to MBSA challenge stimulated the DH response and this was optimal using subliminal sensitizing concentrations of antigen. A number of antirheumatic agents, immunomodulators mediator antagonists and antiallergies were subsequently examined using the subliminal sensitizing concentration of MBSA. The same drugs were also evaluated using a normal sensitizing procedure. These studies indicate that the sensitizing concentration of antigen is critical in establishing whether a drug will stimulate or suppress a DH response.  相似文献   
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