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   2387篇
  免费   185篇
  国内免费   9篇
耳鼻咽喉   4篇
儿科学   64篇
妇产科学   111篇
基础医学   290篇
口腔科学   28篇
临床医学   188篇
内科学   667篇
皮肤病学   34篇
神经病学   160篇
特种医学   130篇
外科学   201篇
综合类   29篇
一般理论   3篇
预防医学   243篇
眼科学   21篇
药学   114篇
肿瘤学   294篇
  2021年   32篇
  2020年   16篇
  2019年   38篇
  2018年   40篇
  2017年   27篇
  2016年   30篇
  2015年   35篇
  2014年   54篇
  2013年   61篇
  2012年   122篇
  2011年   153篇
  2010年   58篇
  2009年   51篇
  2008年   132篇
  2007年   137篇
  2006年   108篇
  2005年   94篇
  2004年   103篇
  2003年   90篇
  2002年   81篇
  2001年   70篇
  2000年   64篇
  1999年   64篇
  1998年   30篇
  1997年   28篇
  1996年   18篇
  1995年   13篇
  1994年   14篇
  1993年   13篇
  1992年   57篇
  1991年   55篇
  1990年   54篇
  1989年   49篇
  1988年   42篇
  1987年   56篇
  1986年   52篇
  1985年   40篇
  1984年   43篇
  1983年   36篇
  1982年   23篇
  1981年   15篇
  1980年   13篇
  1979年   21篇
  1978年   15篇
  1977年   16篇
  1976年   17篇
  1974年   27篇
  1973年   21篇
  1972年   15篇
  1971年   11篇
排序方式: 共有2581条查询结果,搜索用时 93 毫秒
1.
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   
2.
3.
4.
5.
Pharmacokinetics of high-dose etoposide   总被引:1,自引:0,他引:1  
The pharmacokinetics of etoposide at doses of 1 gm/m2 to 3 gm/m2 were studied in patients with hematologic malignancies. The noncompartmental systemic clearance, mean residence time, steady-state volume of distribution, and elimination half-life were independent of the dose of etoposide, whereas the AUC was proportional to the dose. Comparison of these results with those reported previously indicates that etoposide exhibits linear pharmacokinetics over a thirtyfold range in doses (0.1 to 3 gm/m2).  相似文献   
6.
Background: Classic benzodiazepine agonists induce their clinical effects by binding to a site on [gamma]-aminobutyric acid type A (GABAA) receptors and enhancing receptor activity. There are conflicting data regarding whether the benzodiazepine site is allosterically coupled to [gamma]-aminobutyric acid binding versus the channel open-close (gating) equilibrium. The authors tested the hypothesis that benzodiazepine site ligands modulate [alpha]1[beta]2[gamma]2L GABAA receptor gating both in the absence of orthosteric agonists and when the orthosteric sites are occupied.

Methods: GABAA receptors were recombinantly expressed in Xenopus oocytes and studied using two-microelectrode voltage clamp electrophysiology. To test gating effects in the absence of orthosteric agonist, the authors used spontaneously active GABAA receptors containing a leucine-to-threonine mutation at residue 264 on the [alpha]1 subunit. To examine effects on gating when orthosteric sites were fully occupied, they activated wild-type receptors with high concentrations of a partial agonist, piperidine-4-sulfonic acid.

Results: In the absence of orthosteric agonists, the channel activity of [alpha]1L264T[beta]2[gamma]2L receptors was increased by diazepam and midazolam and reduced by the inverse benzodiazepine agonist FG7142. Flumazenil displayed very weak agonism and blocked midazolam from further activating mutant channels. In wild-type receptors activated with saturating concentrations of piperidine-4-sulfonic acid, midazolam increased maximal efficacy.  相似文献   

7.
8.
The significance of anticardiolipin antibodies (ACAs) prior to renal transplantation is unclear. We studied a cohort of 337 patients who underwent renal transplantation from 1996 to 2001. Follow-up continued until allograft loss, patient death or 31 December 2002. The primary outcome was a composite endpoint of death-censored allograft loss or a 25% reduction in estimated glomerular filtration rate (GFR) from 1-month post-transplant. Secondary outcomes were allograft loss, a 25% reduction in GFR, acute rejection and creatinine at 1 year. IgG and IgM ACA titers were positive (> or =15) in 18.1% of recipients. There were no significant differences at baseline between recipients, except coumadin therapy in those with positive ACA titers (20% vs. 7.4%). Post-transplant, there was no increase in the primary outcome in ACA-positive patients, even after adjustment for anticoagulation with coumadin (HR = 1.42 [0.68, 2.96]). There was no difference in secondary outcomes between those with or without positive titers. Two of five patients with very high titers (>50) who were not anticoagulated had early graft loss. A positive ACA titer prior to kidney transplantation was not associated with inferior renal outcomes after transplantation, although more research is required to address the prognostic significance of very high ACA titers.  相似文献   
9.
This study was designed to assess the reliability and validity of a Quality of Life (QOL) instrument on a sample of 179 allogeneic Bone Marrow Transplant (BMT) survivors. The QOL-BMT tool was developed specifically for this population and was based on the investigators' prior research and a conceptual model of Quality of Life. Patients who were at least 100 days post BMT completed the 30 item visual analogue questionnaire. The instrument measured physical symptoms (e.g., weight loss, frequent colds, skin changes, cataracts, sexual problems), psychological to illness, social concerns (e.g., relationship adjustment, return to work), and spiritual well-being (e.g., sense of control, future goals). Psychometric analysis of the instrument included measures of reliability and validity. The study findings demonstrate the unique aspects of QOL dimensions in BMT survivors and the value of QOL assessment in clinical practice and research.This study was supported by the City of Hope National Medical Center, NCI Cancer Center Core Grant, R30 CA 33572 and the City of Hope BRSG Grant Support.  相似文献   
10.
Carcinoma of the urethra (male and female) is an unusual disease with insufficient clinical experience to be dogmatic about therapeutic recommendations. The onset is usually insidious, with a long interval from the first symptoms to diagnosis, yet lack of local and regional control remains the principal obstacle to cure. Treatment choices and results depend to a great degree on the extent, location, and stage of the lesion. Our conclusion is that good surgery and carefully planned irradiation are equally effective in the management of these tumors.  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