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   1230007篇
  免费   87034篇
  国内免费   3201篇
耳鼻咽喉   16845篇
儿科学   42352篇
妇产科学   34651篇
基础医学   177795篇
口腔科学   34378篇
临床医学   107621篇
内科学   241166篇
皮肤病学   30119篇
神经病学   100060篇
特种医学   48122篇
外国民族医学   347篇
外科学   184023篇
综合类   25201篇
一般理论   437篇
预防医学   93336篇
眼科学   28207篇
药学   87968篇
  3篇
中国医学   2677篇
肿瘤学   64934篇
  2021年   10467篇
  2019年   10825篇
  2018年   15693篇
  2017年   11938篇
  2016年   13859篇
  2015年   15494篇
  2014年   20489篇
  2013年   30458篇
  2012年   41789篇
  2011年   43365篇
  2010年   25813篇
  2009年   23851篇
  2008年   40320篇
  2007年   42727篇
  2006年   43182篇
  2005年   42203篇
  2004年   40658篇
  2003年   39230篇
  2002年   37883篇
  2001年   54020篇
  2000年   55362篇
  1999年   46509篇
  1998年   13272篇
  1997年   11726篇
  1996年   11458篇
  1995年   10885篇
  1994年   10054篇
  1993年   9388篇
  1992年   35118篇
  1991年   34276篇
  1990年   33685篇
  1989年   32324篇
  1988年   29367篇
  1987年   29451篇
  1986年   27456篇
  1985年   26555篇
  1984年   19891篇
  1983年   16768篇
  1982年   10159篇
  1979年   18445篇
  1978年   13328篇
  1977年   11274篇
  1976年   10581篇
  1975年   11374篇
  1974年   13565篇
  1973年   13060篇
  1972年   12072篇
  1971年   11249篇
  1970年   10457篇
  1969年   9748篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
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   
24.
25.
26.
27.
Introduction: The treatment of classical Hodgkin lymphoma (cHL) in children is a story of success. Nowadays, more than 90% of patients are cured and overall survival is nearly 100% at 5 years. Efforts have been made to avoid related effects of therapies; therefore, children are treated using different chemotherapy schemes in comparison with adults.

Areas covered: This review includes a view of the clinical classification and risk assessment in children suffering from HL. The chemotherapy more commonly employed is revisited. The use of PET/CT to evaluate the disease in order to guide therapy is analyzed. New options of chemotherapy and emerging immunotherapy are also included.

Expert opinion: In order to make the right treatment choice, a proper initial assessment of risk is mandatory. The choice of therapy in these kinds of patients must be done according to the experience of the team, and also, the cost and logistics related to the eligible scheme are very important. If possible, efforts must be made to include PET/CT in guiding therapy and avoiding overtreatment and long-term adverse effects in children. New options in immunotherapy are emerging and must be considered with caution in selected patients.  相似文献   

28.

Purpose

Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy.

Methods

Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24 hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.< 8) and PMI (≥3vs.< 3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate.

Results

CTASI pc-ASPECTS, dichotomized at < 8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived.

Conclusion

PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.  相似文献   
29.
30.
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