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   1544649篇
  免费   134355篇
  国内免费   21433篇
耳鼻咽喉   18514篇
儿科学   45072篇
妇产科学   39356篇
基础医学   208736篇
口腔科学   39818篇
临床医学   150439篇
内科学   308542篇
皮肤病学   33973篇
神经病学   122137篇
特种医学   63426篇
外国民族医学   412篇
外科学   230641篇
综合类   66383篇
现状与发展   57篇
一般理论   433篇
预防医学   118968篇
眼科学   34546篇
药学   115565篇
  197篇
中国医学   14499篇
肿瘤学   88723篇
  2021年   19892篇
  2020年   13666篇
  2019年   16434篇
  2018年   21195篇
  2017年   17536篇
  2016年   19227篇
  2015年   24263篇
  2014年   32147篇
  2013年   40086篇
  2012年   51732篇
  2011年   56341篇
  2010年   34626篇
  2009年   31834篇
  2008年   47068篇
  2007年   49434篇
  2006年   50702篇
  2005年   49482篇
  2004年   43442篇
  2003年   42162篇
  2002年   39072篇
  2001年   70374篇
  2000年   72687篇
  1999年   61802篇
  1998年   20083篇
  1997年   18406篇
  1996年   18729篇
  1995年   18765篇
  1994年   17169篇
  1993年   15467篇
  1992年   48779篇
  1991年   47180篇
  1990年   45092篇
  1989年   42759篇
  1988年   39627篇
  1987年   38804篇
  1986年   36481篇
  1985年   35072篇
  1984年   26643篇
  1983年   22306篇
  1982年   13972篇
  1981年   12572篇
  1979年   23661篇
  1978年   17109篇
  1977年   14426篇
  1976年   13206篇
  1975年   13766篇
  1974年   16139篇
  1973年   15430篇
  1972年   14210篇
  1971年   13060篇
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
31.
32.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36 weeks gestational age)...  相似文献   
33.
Cyclotron-produced copper-64 radioisotope tracers offer the possibility to perform both diagnostic investigation by positron emission tomography (PET) and radiotherapy by a theranostic approach with bifunctional chelators. The versatile chemical properties of copper add to the importance of this isotope in medicinal investigation. [64Cu][Cu (ATSM)] has shown to be a viable candidate for imaging of tumor hypoxia; a critical tumor microenvironment characteristic that typically signifies tumor progression and resistance to chemo-radiotherapy. Various production and radiosynthesis methods of [64Cu][Cu (ATSM)] exist in labs, but usually involved non-standardized equipment with varying production qualities and may not be easily implemented in wider hospital settings. [64Cu][Cu (ATSM)] was synthesized on a modified GE TRACERlab FXN automated synthesis module. End-of-synthesis (EOS) molar activity of [64Cu][Cu (ATSM)] was 2.2–5.5 Ci/μmol (HPLC), 2.2–2.6 Ci/μmol (ATSM-titration), and 3.0–4.4 Ci/μmol (ICP-MS). Radiochemical purity was determined to be >99% based on radio-HPLC. The final product maintained radiochemical purity after 20 h. We demonstrated a simple and feasible process development and quality control protocols for automated cyclotron production and synthesis of [64Cu][Cu (ATSM)] based on commercially distributed standardized synthesis modules suitable for PET imaging and theranostic studies.  相似文献   
34.

Objectives

To determine: (i) the behaviour change techniques used by a sample of Australian physiotherapists to promote non-treatment physical activity; and (ii) whether those behaviour change techniques are different to the techniques used to encourage adherence to rehabilitation exercises.

Design

Cross-sectional survey.

Method

An online self-report survey was advertised to private practice and outpatient physiotherapists treating patients with musculoskeletal conditions. The use of 50 behaviour change techniques were measured using five-point Likert-type scale questions.

Results

Four-hundred and eighty-six physiotherapists responded to the survey, with 216 surveys fully completed. Most respondents (85.1%) promoted non-treatment physical activity often or all of the time. Respondents frequently used 29 behaviour change techniques to promote non-treatment physical activity or encourage adherence to rehabilitation exercises. A similar number of behaviour change techniques was frequently used to encourage adherence to rehabilitation exercises (n = 28) and promote non-treatment physical activity (n = 26). Half of the behaviour change techniques included in the survey were frequently used for both promoting non-treatment physical activity and encouraging adherence to rehabilitation exercises (n = 25). Graded tasks was the most, and punishment was the least, frequently reported technique used to promote non-treatment physical activity and encourage adherence to rehabilitation exercises.

Conclusions

Respondents reported using similar behaviour change techniques to promote non-treatment physical activity and encourage adherence to rehabilitation exercises. The variability in behaviour change technique use suggests the behaviour the physiotherapist is promoting influences their behaviour change technique choice. Including the frequently-used behaviour change techniques in non-treatment physical activity promotion interventions might improve their efficacy.  相似文献   
35.
36.
37.
目的探讨脑卒中患者急性应激障碍发生现状及影响因素。方法采用斯坦福急性应激反应问卷对349例脑卒中住院患者进行调查。结果共163例(46.70%)患者发生急性应激障碍;Logistic回归分析结果显示,患者性格、是否存在偏瘫及是否吞咽功能障碍是脑卒中患者发生急性应激障碍的主要影响因素(P0.05,P0.01)。结论脑卒中患者急性应激障碍发生率较高,内向性格及存在偏瘫和吞咽功能障碍的患者更容易发生急性应激障碍。医护人员应及时为高危患者提供个体化治疗及预见性护理,防止脑卒中患者发生急性应激障碍。  相似文献   
38.
39.
Monitoring variations in the functioning of the autonomic nervous system may help personalize training of runners and provide more pronounced physiological adaptations and performance improvements. We systematically reviewed the scientific literature comparing physiological adaptations and/or improvements in performance following training based on responses of the autonomic nervous system (ie, changes in heart rate variability) and predefined training. PubMed, SPORTDiscus, and Web of Science were searched systematically in July 2019. Keywords related to endurance, running, autonomic nervous system, and training. Studies were included if they (a) involved interventions consisting predominantly of running training; (b) lasted at least 3 weeks; (c) reported pre- and post-intervention assessment of running performance and/or physiological parameters; (d) included an experimental group performing training adjusted continuously on the basis of alterations in HRV and a control group; and (e) involved healthy runners. Five studies involving six interventions and 166 participants fulfilled our inclusion criteria. Four HRV-based interventions reduced the amount of moderate- and/or high-intensity training significantly. In five interventions, improvements in performance parameters (3000 m, 5000 m, Loadmax, Tlim) were more pronounced following HRV-based training. Peak oxygen uptake () and submaximal running parameters (eg, LT1, LT2) improved following both HRV-based and predefined training, with no clear difference in the extent of improvement in . Submaximal running parameters tended to improve more following HRV-based training. Research findings to date have been limited and inconsistent. Both HRV-based and predefined training improve running performance and certain submaximal physiological adaptations, with effects of the former training tending to be greater.  相似文献   
40.
Purpose: To use polymerase chain reaction (PCR) and Goldmann-Witmer coefficient (GWC) calculation to diagnose infectious uveitis.

Methods: Prospective cross-sectional study.

Results: Twenty-seven of 106 patients had positive PCR and/or GWC results on aqueous humor (AH) sampling and 15 of 27 (55.6%) were HIV-positive. Patients with non-anterior uveitis (NAU) were more likely to be HIV+ (p = 0.005). More than 1 possible pathogen was identified in 9 of 27 patients of whom 7 were HIV+. The final clinical diagnosis was discordant with AH findings in 9 of 27 cases. A positive EBV PCR result was associated with a discordant diagnosis (p = 0.001). All cases of herpetic anterior uveitis (42.9% HIV+) tested PCR-/GWC+ while all cases of herpetic NAU tested PCR+/GWC- (83.3% HIV+). All rubella virus cases were PCR+/GWC+.

Conclusion: PCR is useful to diagnose herpetic NAU in HIV+ patients while GWC is useful to diagnose herpetic anterior uveitis.  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