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   675篇
  免费   30篇
  国内免费   5篇
耳鼻咽喉   3篇
儿科学   34篇
妇产科学   8篇
基础医学   61篇
口腔科学   16篇
临床医学   91篇
内科学   154篇
皮肤病学   32篇
神经病学   15篇
特种医学   124篇
外科学   58篇
综合类   26篇
预防医学   23篇
眼科学   4篇
药学   33篇
  1篇
肿瘤学   27篇
  2023年   1篇
  2022年   3篇
  2021年   3篇
  2020年   2篇
  2019年   4篇
  2018年   8篇
  2017年   3篇
  2016年   8篇
  2015年   10篇
  2014年   11篇
  2013年   15篇
  2012年   4篇
  2011年   11篇
  2010年   28篇
  2009年   32篇
  2008年   18篇
  2007年   30篇
  2006年   31篇
  2005年   27篇
  2004年   15篇
  2003年   10篇
  2002年   10篇
  2001年   16篇
  2000年   12篇
  1999年   9篇
  1998年   40篇
  1997年   45篇
  1996年   38篇
  1995年   19篇
  1994年   30篇
  1993年   23篇
  1992年   14篇
  1991年   11篇
  1990年   13篇
  1989年   28篇
  1988年   24篇
  1987年   11篇
  1986年   12篇
  1985年   6篇
  1984年   17篇
  1983年   17篇
  1982年   12篇
  1981年   11篇
  1980年   7篇
  1979年   1篇
  1978年   3篇
  1977年   2篇
  1976年   4篇
  1969年   1篇
排序方式: 共有710条查询结果,搜索用时 9 毫秒
71.
72.
73.
During a four-year period, 308 patients presented following ingestion of foreign bodies. Ingestion was accidental in 272 cases (88.3%) and deliberate in the remainder. Symptoms at presentation included dysphagia, odynophagia, nausea and vomiting, chest pain and pharyngeal discomfort. Sixty-eight patients were asymptomatic. A policy of expectant management and selective endoscopy was employed. Following initial assessment 202 patients (65.6%) were discharged without treatment, 30 (9.7%) of whom were later reviewed as outpatients and did not require admission. Forty-nine patients (16%) were admitted for treatment; 27 had oesophagoscopy, five bronchoscopy and two had foreign body extraction with direct laryngoscopy. In nine patients who were endoscoped, no foreign body was identified. Twenty-seven others were referred to the otorhinolaryngology service in another hospital. There were no deaths in the group and morbidity was 1.2%. We conclude that a policy of selective endoscopy is safe and effective in the management of patients following ingestion of foreign bodies.  相似文献   
74.
Azidothymidine (AZT) and interferon alpha (IFN-alpha) are among the drugs showing strong in vitro activity against the human immunodeficiency virus type-1 (HIV-1). Each drug, however, has significant toxicity against normal marrow progenitor cells that frequently proves dose-limiting in patients. In this study, AZT and recombinant IFN-alpha 2a (rIFN-alpha 2a) were tested as single agents and in combination against normal myeloid (CFU-GM) and erythroid (BFU- E) colony forming cells in a standard methylcellulose culture assay. The data were analyzed using a quantitative computerized analysis based on the median-effect principle and the isobologram equation as described by Chou and Talalay (Adv Enz Regul 22:27, 1984). The ED90 for BFU-E and CFU-GM inhibition was then compared with previously measured in vivo plasma levels of each drug and the ED90 for the anti-HIV-1 effect in vitro. We demonstrate that (a) the drugs are strongly synergistic in inhibiting marrow progenitor cell growth and that this synergism occurs at drug levels that are within the range of measured plasma levels in phase I clinical trials, (b) BFU-E are more sensitive than CFU-GM to the inhibiting effects of AZT, rIFN-alpha 2a or both drugs in combination, (c) the drug concentrations in combination that synergistically inhibit bone marrow progenitors are much higher than those required to inhibit HIV-1 replication in vitro, and (d) the anti- HIV-1 effect for the combination of AZT and rIFN-alpha 2a was clearly superior to the effect of AZT or rIFN-alpha 2a alone as indicated by the combination index and the dose-reduction index. These data suggest that substantially lower doses of AZT and rIFN-alpha than those currently being tested in clinical trials might not only maintain a strong synergistic anti-HIV-1 effect but might also avoid significant hematologic toxicity.  相似文献   
75.
Late conduction defects following aortic valve replacement   总被引:1,自引:0,他引:1  
BACKGROUND AND AIM OF THE STUDY: The study aim was to determine the incidence and clinical significance of late cardiac conduction defects (CD) after aortic valve replacement (AVR). METHODS: An analysis was made of 100 consecutive cases after AVR in a prospective outpatient evaluation program. RESULTS: The perioperative (30-day) mortality rate was 5%, and incidence of perioperative pacemaker implantation 3%. Among patients, 19% had CDs before surgery; a normal ECG was present during all periods in 45% of patients. The most frequent perioperative CD was left anterior hemiblock (LAHB; n = 8), and the most frequent late CD was left bundle branch block (LBBB; n = 8). Overall, 13.7% of operative survivors with normal preoperative and perioperative ECGs developed late CDs; one patient (1%) required pacemaker implantation 82 months after AVR. A further three patients (3%) had worsening of pre-existent CDs. Late CDs occurred over a wide time range (3 to 102 months) after surgery. CONCLUSION: There is an important incidence of CDs that occur late after AVR, even if the perioperative ECGs are normal; however, a need for late pacemaker implantation is rare. As CDs may occur at any time after surgery, regular follow up with precise evaluation of ECGs is called for.  相似文献   
76.
77.
78.
79.
80.
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