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   1943篇
  免费   126篇
  国内免费   6篇
耳鼻咽喉   1篇
儿科学   44篇
妇产科学   28篇
基础医学   203篇
口腔科学   27篇
临床医学   223篇
内科学   508篇
皮肤病学   57篇
神经病学   151篇
特种医学   121篇
外科学   226篇
综合类   133篇
一般理论   1篇
预防医学   179篇
眼科学   21篇
药学   92篇
  1篇
肿瘤学   59篇
  2022年   15篇
  2021年   51篇
  2020年   25篇
  2019年   44篇
  2018年   31篇
  2017年   25篇
  2016年   19篇
  2015年   35篇
  2014年   42篇
  2013年   59篇
  2012年   92篇
  2011年   80篇
  2010年   57篇
  2009年   61篇
  2008年   81篇
  2007年   68篇
  2006年   87篇
  2005年   80篇
  2004年   78篇
  2003年   70篇
  2002年   59篇
  2001年   44篇
  2000年   48篇
  1999年   45篇
  1998年   51篇
  1997年   33篇
  1996年   45篇
  1995年   27篇
  1994年   39篇
  1993年   23篇
  1992年   36篇
  1991年   25篇
  1990年   26篇
  1989年   29篇
  1988年   33篇
  1987年   28篇
  1986年   36篇
  1985年   23篇
  1984年   26篇
  1983年   30篇
  1982年   25篇
  1981年   14篇
  1980年   14篇
  1979年   20篇
  1978年   16篇
  1977年   14篇
  1976年   16篇
  1975年   16篇
  1974年   14篇
  1967年   12篇
排序方式: 共有2075条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Rising malpractice rates and damages to finances and reputations caused by litigation are leading risk managers to seek new solutions to reduce the frequency and severity of malpractice. Any effort to meet the challenges of malpractice must consider three areas: the informed consent process, expectation management and physician communication. Technology is emerging as an important tool that can help risk managers better address these critical areas. This article explores the realities of malpractice today — specifically the factors behind the majority of cases and discusses how new tools can help risk managers.  相似文献   
5.
6.
7.
In this study we examined the physical, hematologic, and exercise response of 20 male and 10 female athletes of the National Intercollegiate Rodeo Association, Central Rocky Mountain Region. Male subjects were grouped by roughstock, steer wrestling, and roping events. Female athletes were grouped separately. Maximal aerobic capacity, pulmonary ventilation, respiratory exchange ratio, energy expenditure, maximal heart rate, blood pressure, treadmill time, pre- and postexercise lactate, percent body fat, lean body mass, blood chemistry, serum lipids, and reaction/movement time were analyzed by event. No significant differences (P greater than 0.05) were found in any of these categories between male events. Mean resting blood chemistry parameters of rodeo athletes were within normal ranges. Steer wrestling athletes possessed greater body size and lean body mass than other groups. When analyzing body composition, blood pressure, and total cholesterol:high-density lipoprotein (HDL) cholesterol ratios, results indicate average to low risk for coronary heart disease. When compared to other intermittent-activity sport athletes, college rodeo athletes appear to have similar aerobic capacities, but possess lower lean body mass and greater percent body fat.  相似文献   
8.
In order to evaluate the effects of pentoxifylline on sperm motility and longevity, a controlled in-vitro study was conducted on normozoospermic donor semen samples using the Cellsoft automated system for sperm motility analysis. After incubation and selection, pentoxifylline was found to improve the recovery of spermatozoa and to increase their velocity. In the subgroup of progressively motile spermatozoa, curvilinear velocity was also enhanced. It is concluded that pentoxifylline has an effect on the vigour, but not on the pattern, of sperm motion. Pentoxifylline did not improve the motility characteristics of senescent spermatozoa in normozoospermic sperm samples. Sperm survival, as shown by supra-vital staining, and motility longevity both decreased with time after pentoxifylline treatment.  相似文献   
9.
This study was carried out to estimate the prevalence of respiratory symptoms among people aged 65 years and older and assess the value of a postal survey in obtaining this information. A questionnaire was sent to 2011 subjects (957 men) drawn by age-stratified random sampling from the age-sex registers of four New Forest group practices (1:3.3 sample). A total of 1803 replied, a 96.2% response after excluding 136 who had died or moved from the area. The accuracy of replies was verified for 355 (20%) randomly selected subjects. Forty per cent had no respiratory symptoms. Exertional breathlessness was common (38%), increasing in prevalence with age but not with smoking history, and was the only symptom reported by 10% of subjects. Only 14.2% were current smokers; more of the subjects aged 85 years and over were lifelong non-smokers. Two hundred and ninety-six (16.4%) had chronic bronchitis, which was more common among smokers; 151 (8.4%) gave a history of asthma, of whom half (76) had active asthma, which was slightly less common among the very elderly subjects. Only 489 (27.1%) of subjects had seen their doctors with chest symptoms during the preceding 2 years.  相似文献   
10.
Awareness of cognitive dysfunction shown by individuals with Mild Cognitive Impairment (MCI), a condition conferring risk for Alzheimer's disease (AD), is variable. Anosognosia, or unawareness of loss of function, is beginning to be recognized as an important clinical symptom of MCI. However, little is known about the brain substrates underlying this symptom. We hypothesized that MCI participants' activation of cortical midline structures (CMS) during self-appraisal would covary with level of insight into cognitive difficulties (indexed by a discrepancy score between patient and informant ratings of cognitive decline in each MCI participant). To address this hypothesis, we first compared 16 MCI participants and 16 age-matched controls, examining brain regions showing conjoint or differential BOLD response during self-appraisal. Second, we used regression to investigate the relationship between awareness of deficit in MCI and BOLD activity during self-appraisal, controlling for extent of memory impairment. Between-group comparisons indicated that MCI participants show subtly attenuated CMS activity during self-appraisal. Regression analysis revealed a highly significant relationship between BOLD response during self-appraisal and self-awareness of deficit in MCI. This finding highlights the level of anosognosia in MCI as an important predictor of response to self-appraisal in cortical midline structures, brain regions vulnerable to changes in early AD.  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