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   1323010篇
  免费   103871篇
  国内免费   2080篇
耳鼻咽喉   18866篇
儿科学   46149篇
妇产科学   36343篇
基础医学   188042篇
口腔科学   34124篇
临床医学   117139篇
内科学   266209篇
皮肤病学   29109篇
神经病学   104993篇
特种医学   52220篇
外国民族医学   660篇
外科学   201441篇
综合类   27562篇
现状与发展   2篇
一般理论   461篇
预防医学   102246篇
眼科学   28680篇
药学   98016篇
  2篇
中国医学   2480篇
肿瘤学   74217篇
  2019年   10754篇
  2018年   14852篇
  2017年   11307篇
  2016年   12338篇
  2015年   13889篇
  2014年   19306篇
  2013年   29079篇
  2012年   40264篇
  2011年   42170篇
  2010年   25097篇
  2009年   23739篇
  2008年   39932篇
  2007年   42509篇
  2006年   42529篇
  2005年   41351篇
  2004年   40098篇
  2003年   38613篇
  2002年   37674篇
  2001年   64283篇
  2000年   66732篇
  1999年   56717篇
  1998年   15483篇
  1997年   14013篇
  1996年   14409篇
  1995年   13652篇
  1994年   12925篇
  1993年   11934篇
  1992年   44737篇
  1991年   43595篇
  1990年   42350篇
  1989年   40249篇
  1988年   37009篇
  1987年   36314篇
  1986年   33689篇
  1985年   32345篇
  1984年   24213篇
  1983年   20342篇
  1982年   11764篇
  1981年   10713篇
  1979年   21380篇
  1978年   14864篇
  1977年   12557篇
  1976年   11750篇
  1975年   12678篇
  1974年   14702篇
  1973年   14168篇
  1972年   12985篇
  1971年   11781篇
  1970年   11097篇
  1969年   10056篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.

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   
92.
93.
94.
95.
96.
97.
Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host’s immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis.  相似文献   
98.
99.
100.
Thyroid diseases are common, and use of levothyroxine is increasing worldwide. We investigated the influence of gender, race and socioeconomic status on the diagnosis and treatment of thyroid disorders using data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicenter cohort study of civil servants (35-74 years of age) from six Brazilian cities. Diagnosis of thyroid dysfunction was by thyrotropin (TSH), and free thyroxine (FT4) if TSH was altered, and the use of specific medications. Multivariate logistic regression models were constructed using overt hyperthyroidism/hypothyroidism and levothyroxine use as dependent variables and sociodemographic characteristics as independent variables. The frequencies of overt hyper- and hypothyroidism were 0.7 and 7.4%, respectively. Using whites as the reference ethnicity, brown, and black race were protective for overt hypothyroidism (OR=0.76, 95%CI=0.64-0.89, and OR=0.53, 95%CI=0.43-0.67, respectively, and black race was associated with overt hyperthyroidism (OR=1.82, 95%CI=1.06-3.11). Frequency of hypothyroidism treatment was higher in women, browns, highly educated participants and those with high net family incomes. After multivariate adjustment, levothyroxine use was associated with female gender (OR=6.06, 95%CI=3.19-11.49) and high net family income (OR=3.23, 95%CI=1.02-10.23). Frequency of hyperthyroidism treatment was higher in older than in younger individuals. Sociodemographic factors strongly influenced the diagnosis and treatment of thyroid disorders, including the use of levothyroxine.  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