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   28702篇
  免费   2954篇
  国内免费   62篇
耳鼻咽喉   329篇
儿科学   955篇
妇产科学   764篇
基础医学   3958篇
口腔科学   478篇
临床医学   3696篇
内科学   5420篇
皮肤病学   498篇
神经病学   3090篇
特种医学   633篇
外国民族医学   1篇
外科学   3238篇
综合类   426篇
一般理论   29篇
预防医学   3642篇
眼科学   350篇
药学   2307篇
中国医学   50篇
肿瘤学   1854篇
  2023年   289篇
  2022年   508篇
  2021年   1021篇
  2020年   625篇
  2019年   940篇
  2018年   1031篇
  2017年   679篇
  2016年   725篇
  2015年   822篇
  2014年   1090篇
  2013年   1361篇
  2012年   2049篇
  2011年   2001篇
  2010年   1089篇
  2009年   939篇
  2008年   1583篇
  2007年   1482篇
  2006年   1344篇
  2005年   1278篇
  2004年   1146篇
  2003年   953篇
  2002年   898篇
  2001年   558篇
  2000年   487篇
  1999年   462篇
  1998年   238篇
  1997年   226篇
  1996年   203篇
  1995年   190篇
  1994年   178篇
  1993年   162篇
  1992年   421篇
  1991年   361篇
  1990年   325篇
  1989年   309篇
  1988年   345篇
  1987年   290篇
  1986年   265篇
  1985年   221篇
  1984年   245篇
  1983年   194篇
  1982年   142篇
  1980年   112篇
  1979年   193篇
  1978年   123篇
  1976年   132篇
  1975年   132篇
  1974年   121篇
  1973年   113篇
  1972年   119篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
To make a preliminary assessment of whether upper limb soft tissue disorders might be associated with activities at work, we have conducted a case-control study of subjects attending orthopedic clinics in three cities. All subjects between the ages of 16 and 65 years, in whom defined soft tissue conditions of the upper limb were diagnosed by the participating orthopedic surgeons, were invited to take part. Controls were subjects attending the same clinics within the same age range whose clinical diagnosis did not include disease of the upper limb, cervical or thoracic spine. Information concerning repetitive movements of the upper limbs at work was elicited by questionnaire. Five hundred eighty cases and 996 controls were studied, representing 96% and 93%, respectively, of those invited to participate. The diagnoses of the cases included soft tissue conditions affecting the shoulder, elbow, forearm, wrist, thumb, hand, and fingers. The diagnoses of the controls included traumatic, degenerative, and inflammatory conditions, mostly of the legs and lower back. Women predominated among the cases (70%) and men among the controls (56%). Of 221 female cases with injury to the wrist and forearm, 32 were cleaner/domestics (14.5%) compared to 35 of 439 controls (8%), a difference statistically significant at the 2 1/2% level. Other jobs significantly overrepresented (5% level) among female cases with injuries at various anatomical sites included hairdressers, secretary/temps, assembly line workers, and machine operators (type unspecified). Among male cases, electricians were significantly overrepresented (5% level). Jobs for which there was a suggestion (p < 0.1) of overrepresentation among cases included butchers and teacher/ lecturers (both males only) and the combined job groups (chosen a priori for analysis) of keyboard operators, machine operators, and music teachers (all three jobs, females only).  相似文献   
152.
153.
154.
155.
Stress arising from academic performance affects many college students. Moreover, students account for the majority of participants in cardiovascular reactivity research. The current research comprised three brief experiments investigating different aspects of student samples. In Experiment 1, students' (n = 30) academic fear of failure was found to be negatively correlated with systolic blood pressure reactivity. In Experiment 2, students' (n= 13) blood pressure was found to be significantly elevated 2 weeks before college examinations, compared with postexamination levels. Finally, in Experiment 3, students' (n = 19) examination performance was positively correlated with preexamination cardiovascular reactivity. These findings suggest specific college‐related factors that influence the cardiovascular stress response in students and, therefore, should aid the interpretation of much research conducted in cardiovascular health psychology.  相似文献   
156.
This paper reports the psychometric testing of the Worthing Chemotherapy Questionnaire(WCQ). The WCQ is a patient self-report instrument to document side-effects of chemotherapy. Literature review of relevant studies shows that psychometric testing of similar instruments is rarely rigorous. Content validity for the WCQ was established in five ways: literature review, Delphi review among oncology staff, pre-pilot unstructured interviews, pilot study and amendment of the instrument and items for spontaneous reporting of problems on the questionnaire. A three-stage approach to construct validity was used. The hypothesis adopted was that as certain cytotoxic agents cause stomatitis, incidence and severity of stomatitis will decrease following cessation of treatment. Stage 1: factor analysis confirmed the presence of a sole factor, with an eigenvalue of 5.3, for mouth problems which explained 65.5% of the variance. Stage 2: the hypothesis was confirmed using research findings. Stage 3: the Wilcoxon test showed highly significant results for during and post chemotherapy stomatitis scores. Reliability of the questionnaire was assessed using the test-retest method. Weighted Kappa was chosen as the test statistic. A median value of wK=0.87 was obtained. The results indicate that the WCQ is a reliable and valid instrument.  相似文献   
157.
1. In a randomized, double-blind trial we compared the inhibition of the platelet-vessel wall interactions in whole blood ex vivo. There were four groups of 24 healthy volunteers each of whom were treated orally for 3.5 days with either 200 mg dipyridamole (sustained release preparation), 25 mg acetylsalicylic acid, both drugs combined or placebo twice daily. 2. The mean area of all platelets/aggregates was reduced by 6.2% +/- 4.2% (+/- s.e. mean) by placebo (n = 23), 19.8% +/- 6.7% by dipyridamole (n = 22), 53.7% +/- 4.9% by acetylsalicylic acid (n = 23) and 71.4% +/- 3.7% by the combination of both drugs (n = 24), when compared with total inhibition of aggregation by EGTA. Thus, low-dose acetylsalicylic acid inhibited aggregation (P less than 0.001). 3. Dipyridamole reduced the size of platelet aggregates (P less than 0.01, two-fold analysis of variance). The reduction was correlated with the individual dipyridamole plasma levels (P less than 0.05, analysis of covariance). The subgroup of large and very large thrombi being formed was also reduced by dipyridamole (P less than 0.05). 4. This ex vivo study demonstrates that dipyridamole alone inhibits formation of thrombi on subendothelial matrix and enhances the inhibitory effect of low dose acetylsalicylic acid in this model of thrombosis.  相似文献   
158.
159.
BACKGROUND: Much has been written on ethical issues in dementia, but usually from the point of view of the various professionals involved. Whilst there has been an increasing amount of interest in the psychosocial problems that face the carers of people with dementia, the ethical nature of some of these problems has largely been ignored. OBJECTIVE: To review the literature on ethical issues in dementia from the perspective of the main, non-professional carers of people with dementia. METHOD: A systematic literature search using Medline, Clinpsych and CINAHL databases between 1982 and 2000. A pilot study of carers. RESULTS: The lay perspective provides both a wide variety of issues and unique approaches. Although in the literature quantitative research answers some questions, it is qualitative research that deepens our understanding of the issues from the perspective of carers. CONCLUSION: It is particularly qualitative research that brings out the ethical issues for carers, which tend to be more varied than the ethical issues raised in the professional literature. Awareness of such issues could inform and shape the support given to carers.  相似文献   
160.
Para-ileostomy hernia: failure of a local repair technique   总被引:3,自引:0,他引:3  
Different techniques of local repair of para-ileostomy herniae have been recommended by a number of authors, but without report of long-term outcome. Two patients presenting electively with symptomatic para-ileostomy herniae are reported. A local repair technique was used in each case because of severe (coexisting) medical disease, but both herniae recurred within 2 years. It is considered that local repair without stomal transposition cannot be recommended. The literature is reviewed.  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