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   2498篇
  免费   254篇
  国内免费   7篇
耳鼻咽喉   6篇
儿科学   87篇
妇产科学   32篇
基础医学   435篇
口腔科学   64篇
临床医学   227篇
内科学   571篇
皮肤病学   32篇
神经病学   229篇
特种医学   69篇
外科学   272篇
综合类   11篇
一般理论   1篇
预防医学   219篇
眼科学   46篇
药学   184篇
中国医学   4篇
肿瘤学   270篇
  2022年   25篇
  2021年   48篇
  2020年   37篇
  2019年   40篇
  2018年   47篇
  2017年   34篇
  2016年   64篇
  2015年   54篇
  2014年   93篇
  2013年   113篇
  2012年   149篇
  2011年   133篇
  2010年   104篇
  2009年   106篇
  2008年   159篇
  2007年   140篇
  2006年   144篇
  2005年   171篇
  2004年   162篇
  2003年   157篇
  2002年   119篇
  2001年   49篇
  2000年   53篇
  1999年   31篇
  1998年   35篇
  1997年   43篇
  1996年   27篇
  1995年   14篇
  1994年   14篇
  1993年   16篇
  1992年   22篇
  1991年   12篇
  1990年   12篇
  1989年   16篇
  1988年   21篇
  1986年   12篇
  1985年   15篇
  1982年   11篇
  1981年   13篇
  1979年   12篇
  1978年   10篇
  1977年   10篇
  1976年   11篇
  1975年   12篇
  1974年   18篇
  1973年   15篇
  1971年   19篇
  1970年   19篇
  1969年   11篇
  1967年   9篇
排序方式: 共有2759条查询结果,搜索用时 15 毫秒
41.
This article deals with the question of whether and how much workplace health promotion measures have infiltrated the working world and which factors determined the results of health promotion programs for the enterprises. To answer this question we conducted a longitudinal study (measuring times: 1997 and 2003) in 150 enterprises in Hessen and Thueringen of the service sector and metal branch. A standardized questionnaire was used to collect the data. One of the results was that the high level of occupational safety and health (OSH) obtained was greatly appreciated by the enterprises interviewed. Many of the enterprises (82.7%) were able to implement at least one workplace health promotion (WHP) measure, mostly assessments of occupational health risks and behavior-oriented offers. The portion of businesses with a very good to sufficient level of workplace health promotion increased clearly from 16.0% in 1997 to 27.4% in 2003. Half of the enterprises interviewed confirmed the need for information and consultation in questions about occupational safety and health issues and workplace health promotion. They expected support particularly from the institutions for statutory occupational accident insurance, health insurance companies, public institutions for labor protection and safety engineering, as well as from the advisory boards of the trade unions. These institutions definitely need to address the consultation requests from the enterprises, as the lack of information and contact persons was one of the reasons why workplace health promotion measures could not be implemented.This study was commissioned by the Hans Boeckler Foundation and the SMBG and translated by Evelyn Jäck  相似文献   
42.
43.
44.
The purpose of this study was to investigate the value of real-time sonoelastography (RTS) of salivary glands for the diagnosis and assessment of glandular damage in primary Sjögren’s syndrome (pSS). After institutional review board approval, 45 pSS patients, 24 sicca patients and 11 healthy controls were investigated prospectively. Questionnaires were completed and Saxon and Schirmer tests and routine blood tests carried out in all patients. All patients underwent B-mode ultrasonography and RTS of parotid and submandibular glands. Abnormal findings were graded from 0 to 48 and from 0 to 16, respectively. Sialoscintigraphy was done according to a routine protocol; scoring ranged from 0 to 12. Statistical analysis comprised receiver operating characteristic curve and multivariate regression analysis. Patients with pSS had higher B-mode (median score = 25 [range: 2–44] vs. 9 [1–20], p < 0.001) and RTS (6.5 [2–13] versus 4 [1–9], p < 0.001) scores than controls with sicca syndrome, yielding areas under the curve of 0.83 and 0.85 (p < 0.05 each), respectively for pSS diagnosis. In cases with an inconclusive B-mode ultrasonography result, RTS (cutoff score: ≥6) led to a sensitive (66.7%) and specific (85.7%) classification of patients and sicca controls. In multivariate regression analysis, RTS (regression coefficient = –0.48, p = 0.005), but not B-mode ultrasonography, reflected impaired salivary gland function according to the Saxon test, whereas none of the subjective measures of dryness or discomfort were related to ultrasonography results. B-mode and RTS results were both associated with sialoscintigraphy scores (regression coefficient = 0.66, p < 0.001, and regression coefficient = 0.55, p = 0.001, respectively). Reproducibility of B-mode ultrasonography and RTS was good, with intra-class correlation coefficients of 0.93 (95% confidence interval: 0.57–0.98) and 0.93 (95% confidence interval: 0.79–0.98), respectively. In summary, RTS might be a useful adjunct to B-mode ultrasonography for diagnosis and assessment of salivary gland impairment in primary Sjögren’s syndrome.  相似文献   
45.
46.
Based on Fredrickson’s Broaden-and-Build Theory of Positive Emotion, we explored the role of school affect (i.e., positive affect in school and negative affect in school) in connecting gratitude, prosocial behavior, and school satisfaction among a sample of 324 (176 males) elementary school students in grades 4 to 6 by using structural equation modeling. The participants completed a packet of questionnaires, including the Gratitude Questionnaire (GQ-6), the Elementary School Students’ Subjective Well-Being in School Scale (ESSSWBSS), and the Primary School Upper Grade Students’ Prosocial Behaviors Questionnaire (PSUGSPBQ). The results showed that elementary school students’ (1) positive affect in school and negative affect in school significantly related to school satisfaction; (2) prosocial behavior fully mediated the relation between gratitude and school satisfaction; (3) gratitude related to school satisfaction indirectly through positive affect in school and negative affect in school. As hypothesized, the effect was stronger for positive affect in school. Limitations and practical applications of the study were discussed.  相似文献   
47.
48.
We developed 17 variable microsatellite markers for the threatened Saiga antelope. Using one Illumina Miseq lane resulted in 105,948 unique fragments containing a microsatellite motif. Eighty-one ordered primer pairs resulted in 26 analyzable fragments, of which 17 markers showed variability in at least one population from Kazakhstan. Number of alleles ranged from 2 to 11 and values of heterozygosity varied from 0.08 to 0.91 (HO) and 0.08 to 0.88 (HE). The markers are currently used to delineate conservation units and to help understanding annual migration dynamics in this species.  相似文献   
49.
50.
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