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   7295篇
  免费   482篇
  国内免费   88篇
耳鼻咽喉   146篇
儿科学   252篇
妇产科学   484篇
基础医学   854篇
口腔科学   131篇
临床医学   663篇
内科学   1790篇
皮肤病学   240篇
神经病学   541篇
特种医学   411篇
外科学   940篇
综合类   53篇
一般理论   1篇
预防医学   511篇
眼科学   116篇
药学   395篇
中国医学   25篇
肿瘤学   312篇
  2023年   32篇
  2022年   68篇
  2021年   177篇
  2020年   86篇
  2019年   204篇
  2018年   268篇
  2017年   139篇
  2016年   141篇
  2015年   156篇
  2014年   237篇
  2013年   277篇
  2012年   329篇
  2011年   405篇
  2010年   283篇
  2009年   286篇
  2008年   359篇
  2007年   452篇
  2006年   358篇
  2005年   355篇
  2004年   307篇
  2003年   264篇
  2002年   277篇
  2001年   230篇
  2000年   280篇
  1999年   194篇
  1998年   142篇
  1997年   102篇
  1996年   92篇
  1995年   78篇
  1994年   77篇
  1993年   71篇
  1992年   123篇
  1991年   97篇
  1990年   116篇
  1989年   105篇
  1988年   120篇
  1987年   82篇
  1986年   78篇
  1985年   53篇
  1984年   51篇
  1983年   28篇
  1982年   29篇
  1980年   20篇
  1979年   19篇
  1977年   30篇
  1976年   23篇
  1975年   27篇
  1974年   22篇
  1973年   21篇
  1972年   18篇
排序方式: 共有7865条查询结果,搜索用时 15 毫秒
1.
2.
Lasers in Medical Science - Studies reported the harmful effects of 2,4-D on body tissues, provoking changes in the anatomy and physiology of the kidneys, liver, and testicles. Thus, the objective...  相似文献   
3.

Background

Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.

Methods

A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon’s institutional review board–approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m2) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.

Results

The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).

Conclusion

Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.

Level of Evidence

Therapeutic Level IV.  相似文献   
4.
5.
Quality of Life Research - This study investigated the PROMIS Self-Efficacy Measure for Managing Chronic Conditions (PROMIS-SE) domain distributions and examined the factor structure of the...  相似文献   
6.
7.
8.
9.
10.
A drug interaction refers to an event in which the usual pharmacological effect of a drug is modified by other factors, most frequently additional drugs. When two drugs are administered simultaneously, or within a short time of each other, an interaction can occur that may increase or decrease the intended magnitude or duration of the effect of one or both drugs. Drugs may interact on a pharmaceutical, pharmacokinetic or pharmacodynamic basis. Pharmacodynamic interactions arise when the alteration of the effects occurs at the site of action. This is a wide field where not only interactions between different drugs are considered but also drug and metabolites (midazolam/alpha-hydroxy-midazolam), enantiomers (ketamine), as well as phenomena such as tolerance (nordiazepam) and sensitization (diazepam). Pharmacodynamic interactions can result in antagonism or synergism and can originate at a receptor level (antagonism, partial agonism, down-regulation, up-regulation), at an intraneuronal level (transduction, uptake), or at an interneuronal level (physiological pathways). Alternatively, psychotropic drug interactions assessed through quantitative pharmaco-EEG can be viewed according to the broad underlying objective of the study: safety-oriented (ketoprofen/theophylline, lorazepam/diphenhydramine, granisetron/haloperidol), strictly pharmacologically-oriented (benzodiazepine receptors), or broadly neuro-physiologically-oriented (diazepam/buspirone). Methodological issues are stressed, particularly drug plasma concentrations, dose-response relationships and time-course of effects (fluoxetine/buspirone), and unsolved questions are addressed (yohimbine/caffeine, hydroxizyne/alcohol).  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