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   1298篇
  免费   66篇
  国内免费   25篇
耳鼻咽喉   4篇
儿科学   60篇
妇产科学   106篇
基础医学   142篇
口腔科学   19篇
临床医学   112篇
内科学   247篇
皮肤病学   8篇
神经病学   55篇
特种医学   315篇
外科学   79篇
综合类   38篇
预防医学   76篇
眼科学   6篇
药学   59篇
中国医学   1篇
肿瘤学   62篇
  2023年   5篇
  2021年   15篇
  2019年   5篇
  2018年   10篇
  2016年   5篇
  2015年   12篇
  2014年   14篇
  2013年   24篇
  2012年   36篇
  2011年   29篇
  2010年   24篇
  2009年   25篇
  2008年   26篇
  2007年   36篇
  2006年   36篇
  2005年   29篇
  2004年   22篇
  2003年   39篇
  2002年   23篇
  2001年   35篇
  2000年   35篇
  1999年   39篇
  1998年   60篇
  1997年   46篇
  1996年   62篇
  1995年   50篇
  1994年   38篇
  1993年   39篇
  1992年   22篇
  1991年   18篇
  1990年   22篇
  1989年   41篇
  1988年   46篇
  1987年   42篇
  1986年   33篇
  1985年   50篇
  1984年   36篇
  1983年   28篇
  1982年   28篇
  1981年   25篇
  1980年   18篇
  1979年   7篇
  1978年   15篇
  1977年   33篇
  1976年   23篇
  1975年   17篇
  1973年   8篇
  1971年   7篇
  1969年   7篇
  1968年   4篇
排序方式: 共有1389条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
BACKGROUND. Biomaterial pretreatment with endothelial cell mitogens may enhance endothelialization. METHODS. Modified fibrin glue (FG) containing 1 ng/cm2 recombinant 125I-labeled fibroblast growth factor type 1 (125I-FGF-1), 20 micrograms/cm2 heparin, 2.86 mg/cm2 fibrinogen, and 2.86 x 10(-2) units/cm2 thrombin was pressure perfused into expanded polytetrafluoroethylene (ePTFE) grafts. Grafts were interposed into infrarenal aortas of 24 New Zealand white rabbits and explanted after 0, 5, 30, and 60 minutes and 1, 7, 14, and 30 days. Residual radioactivity was determined by gamma-counting. Remaining 125I-FGF-1 is expressed as percent of value at time 0. To determine the effect of the FG/FGF-1 on graft healing, three groups of 50 x 4 mm 60 microns internodal-distance nonreinforced ePTFE grafts were implanted in the aortoiliac position of 12 dogs. Group I (n = 12) contained the complete modified FG, group II (n = 6) contained FG with heparin but no FGF-1, and group III (n = 6) contained untreated identical ePTFE. Tritiated thymidine (0.5 microCi/kg) was injected intramuscularly 10 hours before explantation after 7 and 28 days for light and electron microscopy and en face autoradiography. RESULTS. Retention of 125I-FGF-1 showed rapid initial loss (delta %/delta min = -24.1) followed by slow loss after 1 hour (delta %/delta min = -0.03), with 13.4% +/- 6.9% remaining at 1 week and 3.8% +/- 1.1% at 30 days. Every FG/FGF-1 graft at 28 days showed extensive capillary ingrowth and confluent endothelialized luminal surfaces, not seen in any specimen of the other two groups. Autoradiography revealed a significant increase (p less than 0.05) in 3H-thymidine incorporation in the FG/FGF-1 grafts at 28 days versus all groups as a function of time and graft treatment. CONCLUSIONS. Pressure perfusion of an FGF-1/FG suspension into 60 microns internodal-distance ePTFE grafts promotes endothelialization through capillary ingrowth and increased endothelial cell proliferation.  相似文献   
6.
Embargoes and sanctions are tools of foreign policy. They can induce a decline in economic activity in addition to reducing imports and untoward health effects can supervene, especially among older persons and those with chronic illnesses. Often, violations of the rights of life, health, social services, and protection of human dignity occur among innocent civilians in embargoed nations. This paper examines the effects of embargoes and sanctions against several nations, and calls for studies to determine ways in which economic warfare might be guided by the rule of humanitarian international law, to reduce the effects on civilians. It suggests that the ability to trade in exempted goods and services should be improved, perhaps by establishing uniform criteria and definitions for exemptions, operational criteria under which sanctions committees might function, and methods for monitoring the impact of sanctions on civilian populations in targeted states, particularly with regard to water purity, food availability, and infectious-disease control. Prospective studies are advocated, to generate the data needed to provide better information and monitoring capacity than presently exists.  相似文献   
7.
8.
OBJECTIVE: The aim was to establish the potential efficacy, tolerabilityand side-effect profile of electromagnetic therapy as an adjunctto conventional dressings in the treatment of venous leg ulcers. METHOD: A prospective, randomized, double blind controlled clinicaltrial was carried out in a dedicated leg ulcer clinic basedin one urban general practice. Nineteen patients with leg ulcersof confirmed venous aetiology were assessed. The main outcomemeasures were rate and scale of venous leg ulcer healing, changesin patient-reported pain levels, quality of life, degree ofmobility, side effect profile and acceptability to patientsand staff. RESULTS: Sixty-eight per cent of patients attending this dedicated clinicachieved improvements in the size of their ulcer (4, 21%, healedfully) and in reduced pain levels (P < 0.05) during the trial,despite the chronicity of ulcer histories. Patients treatedwith electromagnetic therapy at 800 Hz were found at day 50to have significantly greater healing (P < 0.05) and paincontrol (P < 0.05) than placebo therapy or treatment with600 Hz. All patients reported improved mobility at the end ofthe study. The electromagnetic therapy was well tolerated bypatients, with no differences between groups in reporting adverseevents, and proved acceptable to staff. CONCLUSION: Despite the small numbers in this pilot study, electromagnetictherapy provided significant gains in the healing of venousleg ulcers and reduction in pain. Keywords. Electromagnetic therapy, RCT, leg ulcers, primary care.  相似文献   
9.
Bile duct calculi in patients with primary sclerosing cholangitis   总被引:1,自引:0,他引:1  
  相似文献   
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