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   4214625篇
  免费   333312篇
  国内免费   13826篇
耳鼻咽喉   58634篇
儿科学   134798篇
妇产科学   110460篇
基础医学   650842篇
口腔科学   113399篇
临床医学   382042篇
内科学   759904篇
皮肤病学   105895篇
神经病学   349895篇
特种医学   163594篇
外国民族医学   503篇
外科学   646706篇
综合类   119225篇
现状与发展   23篇
一般理论   2569篇
预防医学   352973篇
眼科学   98807篇
药学   294443篇
  26篇
中国医学   11297篇
肿瘤学   205728篇
  2021年   55713篇
  2020年   35476篇
  2019年   58422篇
  2018年   73648篇
  2017年   56280篇
  2016年   62296篇
  2015年   75332篇
  2014年   109675篇
  2013年   174817篇
  2012年   120712篇
  2011年   126190篇
  2010年   125195篇
  2009年   126520篇
  2008年   112516篇
  2007年   119862篇
  2006年   128658篇
  2005年   123811篇
  2004年   124045篇
  2003年   114446篇
  2002年   103702篇
  2001年   149677篇
  2000年   144533篇
  1999年   134309篇
  1998年   70081篇
  1997年   66206篇
  1996年   64413篇
  1995年   59686篇
  1994年   53771篇
  1993年   50041篇
  1992年   96047篇
  1991年   92642篇
  1990年   89054篇
  1989年   86818篇
  1988年   80023篇
  1987年   78519篇
  1986年   73854篇
  1985年   72981篇
  1984年   61667篇
  1983年   55430篇
  1982年   46019篇
  1981年   43117篇
  1980年   40506篇
  1979年   53106篇
  1978年   44036篇
  1977年   38884篇
  1976年   36269篇
  1975年   36282篇
  1974年   39410篇
  1973年   37636篇
  1972年   35250篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
ABSTRACT

Forensic DNA analysis is dependent on comparing the known and the unknown. Expand the number of known profiles, and the likelihood of a successful match increases. Forensic use of DNA is moving towards comparing samples of unknown origin with publicly available genetic data, such as the records held by genetic genealogy providers. Use of forensic genetic genealogy has yielded a number of recent high-profile successes but has raised ethical and privacy concerns. Navigating family trees is complex, even more so when combined with a comparison of genetic relationships. This intelligence-gathering process has led to occasional false leads, and its use also risks a public backlash, similar to concerns over Cambridge Analytica. A cautious approach to use of this technique is therefore warranted.  相似文献   
994.
Purpose

Robotic approaches have been steadily replacing laparoscopic approaches in metabolic and bariatric surgeries (MBS); however, their superiority has not been rigorously evaluated. The main goal of the study was to evaluate the 5-year utilization trends of robotic MBS and to compare to laparoscopic outcomes.

Methods

Retrospective analysis of 2015–2019 MBSAQIP data. Kruskal-Wallis test/Wilcoxon and Fisher’s exact/chi-square were used to compare continuous and categorical variables, respectively. Generalized linear models were used to compare surgery outcomes.

Results

The use of robotic MBS increased from 6.2% in 2015 to 13.5% in 2019 (N= 775,258). Robotic MBS patients had significantly higher age, BMI, and likelihood of 12 diseases compared to laparoscopic patients. After adjustment, robotic MBS patients showed higher 30-day interventions and 30-day readmissions alongside longer surgery time (26–38 min).

Conclusion

Robotic MBS shows higher intervention and readmission even after controlling for cofounding variables.

Graphical Abstract
  相似文献   
995.
The aim of the study was to explore the relationship between college graduates’ dual self-consciousness, job search clarity and perceived stress, and reveal the mediating role of perceived stress between dual self-consciousness and job search clarity. In this study, 467 college graduates were investigated using the Dual Self-Consciousness Scale, Job Search Clarity Scale, and Perceived Stress Scale. After controlling for gender, age, and region, the results revealed that: (1) private self-consciousness has a significant positive predictive effect on job search clarity; (2) perceived stress has a significant negative predictive effect on job search clarity; (3) perceived stress plays partial mediation effects between private self-consciousness and job search clarity; (4) perceived stress plays complete mediation effects between public self-consciousness and job search clarity; (5) perceived stress has suppressing effects between public self-consciousness and job search clarity.  相似文献   
996.
997.
998.
999.
Definitive radiotherapy is an effective single-modality in T1 glottic cancer. Hypofractionated schemes could offer excellent results in a shorter treatment period. We aimed to evaluate the clinical outcomes and toxicity comparing conventional vs. hypofractionated radiotherapy treatment in T1N0M0-glottic cancer. Between Jan-1st, 2005 and August-1st, 2017, in a prospective cohort study, with 10-year follow-up, 138 patients were treated with conventional schedule 2 Gy/day, total dose 70 Gy/7 weeks (N = 71) or hypofractionated schedule 2, 2–2, 25 Gy/day, total dose 63, 8–63 Gy/5, 5 weeks (N = 67). Endpoints were clinical-response rate, local relapse-free survival (LRFS), laryngectomy-free survival (LFS), toxicity rates, relapse-free survival (RFS), metastasis-free survival (MFS), second tumour-free survival (2TFS), and overall survival (OS). All patients showed a complete clinical response. No differences were found for LRFS (p = 0.869), LFS (p = 0.975), RFS (p = 0.767), MFS (p = 0.601), 2TFS (p = 0.293), or OS (p = 0.685). Acute toxicity for skin and mucosae was similar (p = 0.550 and p = 0.698). Acute laryngeal toxicity was higher in the hypofractionation group (p = 0.004), due to an increase in slight moderate grade. No differences in late laryngeal edema were found (p = 0.989). Radiotherapy offers high rate survival, local control, and larynx preservation after 5–10-year follow-up. A hypofractionation could be preferable, since it offers the same results as conventional with fewer treatment sessions.  相似文献   
1000.
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