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   14909篇
  免费   943篇
  国内免费   95篇
耳鼻咽喉   125篇
儿科学   496篇
妇产科学   350篇
基础医学   2173篇
口腔科学   257篇
临床医学   1313篇
内科学   3629篇
皮肤病学   451篇
神经病学   1578篇
特种医学   311篇
外科学   1318篇
综合类   42篇
一般理论   7篇
预防医学   1261篇
眼科学   278篇
药学   1130篇
中国医学   42篇
肿瘤学   1186篇
  2024年   23篇
  2023年   202篇
  2022年   511篇
  2021年   859篇
  2020年   407篇
  2019年   615篇
  2018年   675篇
  2017年   414篇
  2016年   478篇
  2015年   561篇
  2014年   704篇
  2013年   926篇
  2012年   1293篇
  2011年   1281篇
  2010年   766篇
  2009年   592篇
  2008年   919篇
  2007年   900篇
  2006年   801篇
  2005年   730篇
  2004年   597篇
  2003年   523篇
  2002年   477篇
  2001年   70篇
  2000年   42篇
  1999年   75篇
  1998年   88篇
  1997年   78篇
  1996年   42篇
  1995年   31篇
  1994年   33篇
  1993年   23篇
  1992年   22篇
  1991年   16篇
  1990年   16篇
  1989年   5篇
  1988年   9篇
  1987年   7篇
  1986年   11篇
  1985年   9篇
  1984年   6篇
  1983年   13篇
  1982年   8篇
  1981年   7篇
  1980年   9篇
  1979年   5篇
  1977年   9篇
  1975年   4篇
  1974年   10篇
  1973年   6篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
171.

Objective

To evaluate the impact of the Youth Form Strategy (EFJ, Estrategia Forma Joven) on the attitudes and behaviours of students in the fourth year of compulsory secondary school in Seville, Spain.

Methods

A longitudinal observational design was used with two groups; one received the EFJ (EFJ group) and other did not (non-EFJ group). In the initial evaluation, 402 participants were randomly selected and, in the follow-up at 6 months, 322 participants were evaluated (161 per group). Validated data collection tools were used, and 2 × 2 tables, odds ratio (OR) and general ANOVA for 2 × 2 mixed factorial design (p < 0.05) were calculated.

Results

Favourable effects of the EFJ were found: in the area of sexuality, the percentage of participants who had sexual intercourse in the final assessment was lower in the EFJ group (14.9% vs 23.4%; OR = 0.57), as were counter-effects: start of tobacco use was higher in the EFJ group (19.5% vs 9.1%; OR = 2.43). However, these differences were not statistically significant.

Conclusions

The similarities in the school health promotion programme in centres with and without EFJ may have influenced the lack of conclusive results. Individual and/or group counselling at schools, a distinguishing feature of the EFJ, could have delayed sexual intercourse in the EFJ group. Based on the studies on school health promotion activities, good practices that could help to improve the effectiveness of the EFJ are recommended.  相似文献   
172.
173.
174.
Antibiotic resistance of Staphylococcus-like organisms (STLO) isolated from a recreational sea beach located on the southern coast of the Baltic Sea was studied. The results of the present study showed that STLO inhabiting sand and seawater of the beach strongly differed in the resistance level to tested antibiotics. These microorganisms were most resistant to ampicillin, penicillin, oxytetracycline and susceptible to gentamicin, neomycin and streptomycin. Moreover, the level of antibiotic resistance among bacteria isolated from different parts of the beach also differed. Bacteria inhabiting the seawater, shoreline and the middle part of the beach were more antibiotic-resistant than bacteria isolated from the dune. The majority of bacteria inhabiting the seawater and sand were resistant to 3–8 antibiotics out of 12 tested in this study. Generally, there was no difference in antibiotic resistance between Staphylococcus-like organisms isolated from the surface and subsurface sand layers. STLO strains isolated from Ustka Beach were most resistant to β-lactam and tetracycline antibiotics, and most susceptible to aminoglycosides.  相似文献   
175.
176.
177.
178.
179.
180.
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