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   60500篇
  免费   4513篇
  国内免费   171篇
耳鼻咽喉   584篇
儿科学   2272篇
妇产科学   1665篇
基础医学   8201篇
口腔科学   1499篇
临床医学   7612篇
内科学   11841篇
皮肤病学   1012篇
神经病学   5613篇
特种医学   1236篇
外国民族医学   38篇
外科学   6071篇
综合类   548篇
一般理论   104篇
预防医学   8328篇
眼科学   806篇
药学   3482篇
中国医学   227篇
肿瘤学   4045篇
  2024年   87篇
  2023年   626篇
  2022年   956篇
  2021年   1980篇
  2020年   1210篇
  2019年   1829篇
  2018年   2163篇
  2017年   1548篇
  2016年   1634篇
  2015年   1766篇
  2014年   2431篇
  2013年   3466篇
  2012年   4896篇
  2011年   5165篇
  2010年   2663篇
  2009年   2298篇
  2008年   4048篇
  2007年   4027篇
  2006年   3669篇
  2005年   3525篇
  2004年   3144篇
  2003年   2783篇
  2002年   2626篇
  2001年   522篇
  2000年   409篇
  1999年   491篇
  1998年   505篇
  1997年   388篇
  1996年   320篇
  1995年   334篇
  1994年   295篇
  1993年   251篇
  1992年   229篇
  1991年   197篇
  1990年   184篇
  1989年   156篇
  1988年   150篇
  1987年   107篇
  1986年   129篇
  1985年   136篇
  1984年   141篇
  1983年   116篇
  1982年   131篇
  1981年   164篇
  1980年   122篇
  1979年   81篇
  1978年   79篇
  1977年   70篇
  1976年   74篇
  1974年   70篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
The outbreaks of rabies in humans transmitted by Desmodus rotundus in 2004 and 2005, in the northeast of the Brazilian State of Para, eastern Amazon basin, made this a priority area for studies on this zoonosis. Given this, the present study provides data on this phenomenon in an urban context, in order to assess the possible circulation of the classic rabies virus (RABV) among bat species in Capanema, a town in the Amazon basin. Bats were collected, in 2011, with mist nets during the wet and dry seasons. Samples of brain tissue and blood were collected for virological and serological survey, respectively. None of the 153 brain tissue samples analyzed tested positive for RABV infection, but 50.34% (95% CI: 45.67-55.01%) of the serum samples analyzed were seropositive. Artibeus planirostris was the most common species, with a high percentage of seropositive individuals (52.46%, 95% CI: 52.31 52.60%). Statistically, equal proportions of seropositive results were obtained in the rainy and dry seasons (c2 = 0.057, d.f. = 1, p = 0.88). Significantly higher proportions of males (55.96%, 95% CI: 48.96-62.96%) and adults (52.37%, 95% CI: 47.35-57.39%) were seropositive. While none of the brain tissue samples tested positive for infection, the high proportion of seropositive specimens indicates that RABV may be widespread in this urban area.  相似文献   
42.

Background

We have recently shown that human epididymis protein 4 (HE4) levels correlate with the severity of cystic fibrosis (CF) lung disease. However, there are no data on how HE4 levels alter in patients receiving CFTR modulating therapy.

Methods

In this retrospective clinical study, 3 independent CF patient cohorts (US-American: 29, Australian: 12 and Irish: 19 cases) were enrolled carrying at least one Class III CFTR CF-causing mutation (p.Gly551Asp) and being treated with CFTR potentiator ivacaftor. Plasma HE4 was measured by immunoassay before treatment (baseline) and 1–6?months after commencement of ivacaftor, and were correlated with FEV1 (% predicted), sweat chloride, C-reactive protein (CRP) and body mass index (BMI).

Results

After 1?month of therapy, HE4 levels were significantly lower than at baseline and remained decreased up to 6?months. A significant inverse correlation between absolute and delta values of HE4 and FEV1 (r?=??0.5376; P?<?.001 and r?=??0.3285; P?<?.001), was retrospectively observed in pooled groups, including an independent association of HE4 with FEV1 by multiple regression analysis (β?=??0.57, P?=?.019). Substantial area under the receiver operating characteristic curve (ROC-AUC) value was determined for HE4 when 7% mean change of FEV1 (0.722 [95% CI 0.581–0.863]; P?=?.029) were used as classifier, especially in the first 2?months of treatment (0.806 [95% CI 0.665–0.947]; P?<?.001).

Conclusions

This study shows that plasma HE4 levels inversely correlate with lung function improvement in CF patients receiving ivacaftor. Overall, this potential biomarker may be of value for routine clinical and laboratory follow-up of CFTR modulating therapy.  相似文献   
43.
44.
Purpose: To test the effectiveness of a school-based, nurse-facilitated support group in increasing perceptions of scholastic competence, social acceptance, behavioral conduct, perceived athletic competence, perceived physical appearance, and perceived global self-worth in preadolescents diagnosed with attention deficit disorder (ADD) or attention deficit hyperactivity disorder (ADHD).
Design: A quasi-experimental design with 65 preadolescents diagnosed with ADD or ADHD in an upper-middle class community in the United States.
Methods: Participants randomly assigned to either the control or experimental group completed Harter's Self-Perception Profile for Children instrument at the beginning of the study and 4 weeks later. Students in the experimental condition participated in a school-nurse facilitated support group which met twice weekly for 4 weeks.
Findings: Participants in the support group had increased scores on each of the six subscales, with significant increases on four of the subscales, including perceived social acceptance, perceived athletic competence, perceived physical appearance, and perceived global self-worth.
Conclusion: Participation in a school-based, nurse-led support group was positively associated with perception of self-worth in preadolescents diagnosed with ADD or ADHD.  相似文献   
45.
46.
At the time of hire, 4059 of 6522 healthcare workers required a 2-step tuberculin skin test; 114 workers (2.8%) demonstrated a boosted reaction after the second step. Boosted reactions were significantly associated with male sex and older age. A verbal history of previous tuberculin skin test results was not a reliable indicator of baseline tuberculin skin test status at the time of hire.  相似文献   
47.
48.
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