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   986篇
  免费   47篇
  国内免费   9篇
耳鼻咽喉   1篇
儿科学   58篇
妇产科学   47篇
基础医学   106篇
口腔科学   9篇
临床医学   66篇
内科学   191篇
皮肤病学   23篇
神经病学   138篇
特种医学   155篇
外科学   67篇
综合类   10篇
预防医学   60篇
眼科学   2篇
药学   31篇
  1篇
中国医学   7篇
肿瘤学   70篇
  2023年   4篇
  2022年   5篇
  2021年   10篇
  2019年   7篇
  2018年   17篇
  2017年   15篇
  2016年   12篇
  2015年   18篇
  2014年   22篇
  2013年   27篇
  2012年   28篇
  2011年   22篇
  2010年   33篇
  2009年   39篇
  2008年   28篇
  2007年   35篇
  2006年   23篇
  2005年   17篇
  2004年   19篇
  2003年   29篇
  2002年   17篇
  2001年   27篇
  2000年   25篇
  1999年   33篇
  1998年   33篇
  1997年   32篇
  1996年   45篇
  1995年   40篇
  1994年   39篇
  1993年   23篇
  1992年   12篇
  1991年   19篇
  1990年   14篇
  1989年   32篇
  1988年   29篇
  1987年   24篇
  1986年   23篇
  1985年   25篇
  1984年   18篇
  1983年   12篇
  1982年   9篇
  1981年   12篇
  1980年   13篇
  1979年   10篇
  1978年   6篇
  1977年   9篇
  1976年   7篇
  1975年   5篇
  1935年   3篇
  1933年   8篇
排序方式: 共有1042条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
目的:了解延边地区朝鲜族和汉族居民的脂肪分布特征及其与血压、血脂及血糖的关系。方法:于2006-08-8/17在延边地区九龙和翁声社区随机选择40~60岁朝鲜族和汉族常住居民2378名进行内脏脂肪率和体脂肪率以及血压、血脂、血糖等生化指标的检测。调查以健康体检形式进行,①内脏脂肪和体脂肪率测定采用日本TANITA株式会社生产的BC-600型体成分计测定,并且按其判定标准确定超过标准者[内脏脂肪率≥15%(男)、≥10%(女),体脂肪率(40~59岁)≥23%(男)、≥36%(女),体脂肪率(≥60岁)≥25%(男)、≥37%(女)]。②取清晨空腹(禁食12h)静脉血,采用日立-7600-010全自动生化分析仪测量血清总胆固醇、三酰甘油、高密度脂蛋白胆固醇、空腹血糖等指标。③高血压的诊断标准:收缩压≥140mmHg(1mmHg=0.133kPa)及或舒张压≥90mmHg。④血脂异常的诊断标准:总胆固醇≥5.72mmol/L,三酰甘油≥1.7mmol/L,高密度脂蛋白胆固醇<0.90mmol/L(男)、<1.0mmol/L(女)。⑤高血糖的诊断标准:空腹血糖≥6.1mmol/L。结果:①汉族男性的内脏脂肪率和体脂肪率均值分别为(10.51±3.66)%和(22.70±4.85)%,朝鲜族男性分别为(9.16±3.81)%和(20.28±5.02)%,汉族均高于朝鲜族(P<0.01);汉族女性的内脏脂肪率和体脂肪率分别为(6.22±2.27)%和(35.31±5.65)%,朝鲜族女性分别为(5.88±2.19)%和(34.00±5.72)%,汉族均高于朝鲜族(P<0.01)。②汉族男性的内脏脂肪率和体脂肪率超标率分别为12.1%和45.8%,朝鲜族男性分别为7.8%和28.6%,汉族均高于朝鲜族(P<0.05);汉族女性的内脏脂肪率和体脂肪率超标率分别为6.7%和47.9%,朝鲜族女性分别为3.8%和37.3%,汉族均高于朝鲜族(P<0.05)。③Logistic逐步回归分析结果表明,内脏脂肪率与民族、性别、年龄、高血压、高三酰甘油血症和高血糖有密切关系;体脂肪率与民族、性别、高血压、高三酰甘油血症、低高密度脂蛋白血症和高血糖有密切的关系。结论:①延边地区汉族居民内脏脂肪率和体脂肪率平均水平及其超标率明显高于朝鲜族。②内脏脂肪率和体脂肪率均与民族、性别、年龄(体脂肪率除外)、高血压、高三酰甘油血症和高血糖相关。  相似文献   
86.
This double-blind, randomized, crossover study examined the effects of intravenous infusion of esmolol (a new ultra-short-acting beta-receptor blocking agent) and propranolol on cardiovascular performance at rest and during peak upright exercise in 15 patients. Biventricular function was assessed by means of first-pass radionuclide ventriculography with a computerized multicrystal camera. At rest, significant treatment differences between esmolol and propranolol vs baseline were found for the heart rate, systolic blood pressure, double product, left ventricular ejection fraction (EF), systolic blood pressure to end-systolic volume ratio, cardiac index and right ventricular EF. During exercise, significant treatment differences were also found for the heart rate, systolic blood pressure, double product, right ventricular EF and cardiac index. The mean baseline measurements were higher than the mean treatment measurements, but no significant differences were found between mean esmolol and mean propranolol measurements at rest and during exercise except for the exercise systolic blood pressure, which was lower during esmolol infusion. The magnitude of drug effect was greater at the time of exercise than at rest. The blood level of esmolol decreased markedly by 30 minutes after infusion. Esmolol was well tolerated, with no important local, systemic or laboratory abnormalities. Thus, the effects of esmolol on cardiovascular performance at rest and exercise are similar to those of propranolol.  相似文献   
87.

INTRODUCTION

Since the invasion of Iraq in 2003, the conflict has evolved from asymmetric warfare to a counter-insurgency operation. This study investigates the pattern of wounding and types of injuries seen in casualties of hostile action presenting to a British military field hospital during the present conflict.

PATIENTS AND METHODS

Data were prospectively collected on 100 consecutive patients either injured or killed from hostile action from January 2006 who presented to the sole coalition field hospital in southern Iraq.

RESULTS

Eighty-two casualties presented with penetrating missile injuries from hostile action. Three subsequently died of wounds (3.7%). Forty-six (56.1%) casualties had their initial surgery performed by British military surgeons. Twenty casualties (24.4%) sustained gunshot wounds, 62 (75.6%) suffered injuries from fragmentation weapons. These 82 casualties were injured in 55 incidents (mean, 1.49 casualties; range 1–6 casualties) and sustained a total 236 wounds (mean, 2.88 wounds) affecting a mean 2.4 body regions per patient. Improvised explosive devices were responsible for a mean 2.31 casualties (range, 1–4 casualties) per incident.

CONCLUSIONS

The current insurgency in Iraq illustrates the likely evolution of modern, low-intensity, urban conflict. Improvised explosive devices employed against both military and civilian targets have become a major cause of injury. With the current global threat from terrorist bombings, both military and civilian surgeons should be aware of the spectrum and emergent management of the injuries caused by these weapons.  相似文献   
88.
A stereotactic biopsy of a 17-year-old woman revealed an active inflammatory demyelinating lesion compatible with pattern III multiple sclerosis (MS) according to Lucchinetti et al . The biopsy included a white matter region distant from the active inflammatory demyelinating lesion with abnormal MRI signal, lacking histopathological signs of demyelination and/or oligodendrocyte apoptosis. Expression analysis of this area revealed a strong up-regulation of neuronal nitric oxide synthase (nNOS). Furthermore, detection of nitrotyrosine provided evidence for reactive nitrogen species (RNS)-mediated damage to oligodendrocytes. Concomitantly, genes involved in neuroprotection against oxidative stress such as heme oxygenase 1 were up-regulated. Even though a single case report, this study shows earliest molecular changes in white matter surrounding an actively demyelinating lesion during the first manifestation of MS, pointing toward a more widespread pathological process. Therapeutic targeting of the identified mechanisms of tissue injury might be crucial to prevent further lesion formation or secondary tissue damage.  相似文献   
89.
The Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) Phase 1 Schizophrenia trial compared the effectiveness of one typical and four atypical antipsychotic medications. Although trials such as CATIE present important opportunities for pharmacogenetics research, the very richness of the clinical data presents challenges for statistical interpretation, and in particular the risk that data mining will lead to false-positive discoveries. For this reason, it is both misleading and unhelpful to perpetuate the current practice of reporting association results for these trials one gene at a time, ignoring the fact that multiple gene-by-phenotype tests are being carried out on the same data set. On the other hand, suggestive associations in such trials may lead to new hypotheses that can be tested through both replication efforts and biological experimentation. The appropriate handling of these forms of data therefore requires dissemination of association statistics without undue emphasis on select findings. Here we attempt to illustrate this approach by presenting association statistics for 2769 polymorphisms in 118 candidate genes evaluated for 21 pharmacogenetic phenotypes. On current evidence it is impossible to know which of these associations may be real, although in total they form a valuable resource that is immediately available to the scientific community.  相似文献   
90.
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