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   1838篇
  免费   147篇
  国内免费   7篇
耳鼻咽喉   18篇
儿科学   71篇
妇产科学   21篇
基础医学   229篇
口腔科学   43篇
临床医学   181篇
内科学   395篇
皮肤病学   24篇
神经病学   83篇
特种医学   80篇
外科学   306篇
综合类   45篇
一般理论   1篇
预防医学   121篇
眼科学   42篇
药学   147篇
中国医学   25篇
肿瘤学   160篇
  2023年   17篇
  2022年   32篇
  2021年   52篇
  2020年   34篇
  2019年   41篇
  2018年   54篇
  2017年   39篇
  2016年   40篇
  2015年   47篇
  2014年   60篇
  2013年   67篇
  2012年   112篇
  2011年   110篇
  2010年   75篇
  2009年   70篇
  2008年   138篇
  2007年   109篇
  2006年   122篇
  2005年   105篇
  2004年   114篇
  2003年   95篇
  2002年   93篇
  2001年   45篇
  2000年   40篇
  1999年   39篇
  1998年   29篇
  1997年   20篇
  1996年   20篇
  1995年   19篇
  1994年   13篇
  1993年   12篇
  1992年   9篇
  1991年   5篇
  1990年   16篇
  1989年   12篇
  1988年   8篇
  1987年   10篇
  1986年   11篇
  1985年   8篇
  1984年   3篇
  1983年   5篇
  1982年   11篇
  1981年   5篇
  1980年   4篇
  1979年   5篇
  1978年   3篇
  1977年   2篇
  1975年   3篇
  1973年   2篇
  1967年   2篇
排序方式: 共有1992条查询结果,搜索用时 31 毫秒
1.
2.
The purpose of this study is to determine the role of liver biopsy and outcome of patients undergoing donor evaluation for adult-to-adult right hepatic lobe living donor liver transplantation (LDLT). Records of patients presenting for a comprehensive donor evaluation between 1997 and February 2005 were reviewed. Liver biopsy was performed only in patients with risk factors for abnormal histology. Two hundred and sixty patients underwent a comprehensive donor evaluation and 116 of 260 (45%) were suitable for donation, 14 of 260 (5.4%) did not complete evaluation and 130 of 260 (50%) were rejected. Four patients underwent unsuccessful hepatectomy surgery due to discovery of intraoperative abnormalities. Between 1997 and 2001, the acceptance rate of donor candidates (63%) was higher than 2002-2005 (36%), p < 0.0001. Sixty-six of the 150 eligible patients (44%) fulfilled criteria for liver biopsy and 28 of 66 (42%) had an abnormal finding. Less than half of the patients undergoing donor evaluation were suitable donors and the donor acceptance rate has declined over time. A large proportion of the patients undergoing liver biopsy have abnormal findings. Our evaluation process failed to identify 4 of 103 who had aborted donor surgeries.  相似文献   
3.
Objective: Considering the growing use of cellular phones and the fast appearance of new phone models, the electromagnetic interference of currently popular cellular phones on electronic medical equipment was tested. Methods: Three Personal Communication System cellular phones were put at different distances from multiple electronic medical devices, the interference effect was observed and the electromagnetic field strength measured with a spectrum analyser. Results: Only two small pieces of equipment, the CO2 airway adapter and the haemoglucostix meter were affected and then only when the phone was in very close proximity. Conclusion: Compared to the results of our study in 1997 testing Global System for Mobile Communication phones, the Personal Communication System phones generated less electromagnetic interference. However a much larger scaled study and an accurate international electromagnetic interference standard are recommended before any change in the current restrictive hospital policy on mobile phone usage could be recommended.  相似文献   
4.
5.
SK&F 86466, 6-chloro-3-methyl-2,3,4,5-tetrahydro-1-H-3-benzazepine, is a potent and selective antagonist of the α2-adrenoceptor in vitro. This compound produced a small pressor response accompanied by a marked bradycardia when administered i.v. to the pithed normotensive rat. The pressor response was not affected by reserpine treatment, pretreatment with α- or β-adrenoceptor antagonists, atropine, or hexamethonium. The bradycardia was markedly reduced by bilateral vagotomy and pretreatment with atropine and attenuated by hexamethonium. The negative chronotropic action of SK&F 86466 was abolished by a combination of vagotomy and atropine. Mediation of the bradycardia by a baroreceptor reflex was ruled out by the observations that a lack of change in heart rate was associated with the vasopressor response to phenylephrine in the pithed rat pretreated with propranolol. It is concluded that the negative chronotropic action of SK&F 86466 in the pithed rat is mediated indirectly by activation of the cholinergic innervation of the heart.  相似文献   
6.
1 The reproducibility of angiotensin converting enzyme inhibitor induced cough was examined in a double-blind cross over study in patients previously shown to have exhibited this side effect.

2 Ninety-seven patients who had experienced angiotensin converting enzyme inhibitor cough within the last 2 years were challenged with enalapril 20 mg daily for 4 weeks to establish eligibility. Eighty-eight of 97 (91%) patients experienced a repeat of their cough symptoms. Sixty-four patients entered the double-blind part of the study where they were treated with enalapril 20 mg and a renin inhibitor for up to 4 weeks in random order. These periods were separated by a minimum 4 week placebo wash out.

3 Of 59 evaluable patients who received enalapril a second time, 37 (62.7%) experienced cough again. Of 62 patients on the renin inhibitor 16 (25.8%) experienced cough, however as it was not equi-efficacious to enalapril no valid comparison could be made.

4 Angiotensin converting enzyme inhibitor cough is not reproducible within patients, as other factors are involved in the aetiology. Objective testing with blinded assessment together with symptom reporting, would give a more accurate measure of the incidence, and mechanism of this side effect.

  相似文献   
7.
8.
Small single-institutional studies performed prior to the introduction of organ allocation using the Model for End-Stage Liver Disease (MELD) suggest that early airway extubation of liver transplant recipients is a safe practice. We designed a multicenter study to examine adverse events associated with early extubation in patients selected for liver transplantation using MELD score. A total of 7 institutions extubated all patients meeting study criteria and reported adverse events that occurred within 72 hours following surgery. Adverse events were uncommon: occurring in only 7.7% of 391 patients studied. Most adverse events were pulmonary or surgically related. Pulmonary complications were usually minor, requiring only an increase in ambient oxygen concentration. The majority of surgical adverse events required additional surgery. Analysis of a limited set of perioperative variables suggest that blood transfusions and technical factors were associated with an increased risk of adverse events. In conclusion, while early extubation appears to be safe under specified circumstances, there are performance differences between institutions that remain to be explained.  相似文献   
9.
10.
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