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   6286篇
  免费   520篇
  国内免费   68篇
耳鼻咽喉   71篇
儿科学   222篇
妇产科学   140篇
基础医学   641篇
口腔科学   144篇
临床医学   781篇
内科学   1212篇
皮肤病学   76篇
神经病学   566篇
特种医学   389篇
外科学   899篇
综合类   142篇
一般理论   2篇
预防医学   741篇
眼科学   153篇
药学   346篇
中国医学   8篇
肿瘤学   341篇
  2023年   62篇
  2022年   100篇
  2021年   231篇
  2020年   96篇
  2019年   160篇
  2018年   197篇
  2017年   131篇
  2016年   122篇
  2015年   168篇
  2014年   195篇
  2013年   266篇
  2012年   325篇
  2011年   327篇
  2010年   164篇
  2009年   173篇
  2008年   275篇
  2007年   294篇
  2006年   210篇
  2005年   233篇
  2004年   221篇
  2003年   192篇
  2002年   155篇
  2001年   139篇
  2000年   162篇
  1999年   126篇
  1998年   101篇
  1997年   65篇
  1996年   103篇
  1995年   76篇
  1994年   88篇
  1993年   84篇
  1992年   89篇
  1991年   99篇
  1990年   97篇
  1989年   101篇
  1988年   109篇
  1987年   92篇
  1986年   90篇
  1985年   80篇
  1984年   68篇
  1983年   65篇
  1982年   55篇
  1981年   56篇
  1980年   53篇
  1979年   63篇
  1978年   62篇
  1977年   41篇
  1976年   32篇
  1973年   32篇
  1970年   30篇
排序方式: 共有6874条查询结果,搜索用时 15 毫秒
1.

Objective

Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality.

Methods

From 2005 to 2017, 593 neonates in the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort underwent a Norwood procedure. Median follow-up was 3.7 years. Multivariable parametric models, including a modulated renewal analysis, were performed.

Results

Of the 593 neonates, 146 (25%) underwent 218 reinterventions for arch obstruction after the Norwood procedure: catheter-based (n = 168) or surgical (n = 50) at a median age of 4.3 months (quartile 1-quartile 3, 2.6-5.7). Interdigitation of the distal aortic anastomosis was protective against arch reintervention. Development of ≥ moderate tricuspid valve regurgitation and right ventricular dysfunction at any point was associated with arch reintervention. Nonsignificant variables for arch reintervention included shunt type and preoperative aortic measurements. Surgical arch reintervention was protective against arch reintervention, but transcatheter reintervention was associated with increased reintervention. Arch reintervention was not associated with increased mortality. There was wide institutional variation in incidence of arch reintervention (range, 0-40 reinterventions per 100 years patient follow-up) and in preintervention gradient (range, 0-64 mm Hg).

Conclusions

Interdigitation of the distal aortic anastomosis during the Norwood procedure decreased the risk of arch reintervention. Surgical arch reintervention is more definitive than transcatheter. Arch reintervention after the Norwood procedure is not associated with increased mortality. Serial surveillance for arch obstruction, integrated with changes in right ventricular function and tricuspid valve regurgitation, is recommended after the Norwood procedure to improve outcomes.  相似文献   
2.
3.
4.
5.
6.
Microinjection of the indirect GABAA antagonist, picrotoxin, or the mu opioid agonist, Tyr-D-Ala-Gly-NMe-Phe-Gly-ol (DAGO), into the ventral pallidum and substantia innominata (VP/SI) increases locomotor activity in rats. The VP/SI has direct and indirect projections to the region of the ventral mesencephalon containing dopamine perikarya, and to certain dopamine terminal fields, including the nucleus accumbens. Thus, it is possible that modulation of the mesocorticolimbic dopamine system by pharmacological stimulation in the VP/SI may play a role in the locomotor stimulant response. It was shown that pretreatment with dopamine receptor antagonists, either peripherally or microinjected into the nucleus accumbens significantly attenuated the motor stimulant effect of DAGO or picrotoxin injection into the VP/SI. Injection of either picrotoxin or DAGO into the VP/SI increased the levels of dopamine metabolites in the nucleus accumbens and prefrontal cortex. Thus, the motor stimulant response following pharmacological stimulation of the VP/SI appears to be mediated by increased dopamine neurotransmission via feedback mechanisms to the mesocorticolimbic dopamine system.  相似文献   
7.
8.
9.
Updated information on the pathologic characterization and treatment of olfactory neurobiastoma (ON) and neuroendocrine carcinoma (NEC) diseases is presented. A series of patients with ON or NEC was evaluated and retrospectively staged using the UCLA system. The parameters evaluated were symptoms, age, sex, risk factor assessment, stage of disease, treatment, and clinical outcome. The median follow-up was 3 years (range, 18 months to 23 years). The predominant therapy (63%) for ON was combined surgery and radiotherapy. Surgery alone or in combination with ancillary treatment was used in 58% of patients with NEC. For the most receat years of the study, patients with NEC have been treated successfully with combined chemotherapy and radiotherapy. Seventy percent of the patients with ON and 75% of the patients with NEC were clinically free of disease during the defined follow-up period. Surgical therapy consisting of a craniofacial resection combined with postoperative radiotherapy has resulted in good local and long-term control of ON. Our experience indicates that combined chemoradiation is an appropriate therapeutic approach for NEC.  相似文献   
10.
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