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   9233篇
  免费   455篇
  国内免费   13篇
耳鼻咽喉   171篇
儿科学   273篇
妇产科学   287篇
基础医学   1784篇
口腔科学   277篇
临床医学   722篇
内科学   1452篇
皮肤病学   246篇
神经病学   947篇
特种医学   457篇
外国民族医学   3篇
外科学   1280篇
综合类   48篇
一般理论   3篇
预防医学   444篇
眼科学   298篇
药学   488篇
中国医学   79篇
肿瘤学   442篇
  2022年   60篇
  2021年   99篇
  2020年   74篇
  2019年   107篇
  2018年   141篇
  2017年   110篇
  2016年   129篇
  2015年   195篇
  2014年   216篇
  2013年   283篇
  2012年   445篇
  2011年   468篇
  2010年   322篇
  2009年   311篇
  2008年   422篇
  2007年   400篇
  2006年   431篇
  2005年   384篇
  2004年   413篇
  2003年   382篇
  2002年   344篇
  2001年   181篇
  2000年   199篇
  1999年   200篇
  1998年   101篇
  1997年   84篇
  1996年   61篇
  1995年   65篇
  1994年   52篇
  1993年   56篇
  1992年   106篇
  1991年   82篇
  1990年   102篇
  1989年   92篇
  1988年   95篇
  1987年   74篇
  1986年   62篇
  1985年   98篇
  1984年   60篇
  1979年   59篇
  1978年   51篇
  1977年   55篇
  1975年   48篇
  1974年   47篇
  1971年   56篇
  1970年   42篇
  1930年   45篇
  1929年   45篇
  1928年   43篇
  1922年   44篇
排序方式: 共有9701条查询结果,搜索用时 31 毫秒
1.
2.

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   
3.
4.
Mycophenolate mofetil (MMF) is increasingly used to prevent acute and chronic rejection following kidney transplantation and in autoimmune diseases. Here, we report on a patient after kidney transplantation, who developed an acute inflammatory syndrome characterized by fever and oligoarthritis within 1 week after increasing the MMF dosage. MMF was discontinued resulting in a complete resolution of the syndrome within 48 h. We demonstrated in vitro that the patient's phorbol myristate acetate (PMA-) and formyl Met-Leu-Phe (fMLP-) stimulated polymorphonuclear neutrophils (PMNs) developed increased oxidative burst when incubated with MMF. This report demonstrates that MMF can also induce acute inflammatory syndrome in patients following kidney transplantation and that this syndrome might be due to a paradox, pro-inflammatory reaction of PMNs.  相似文献   
5.
The aim of the project was to determine whether the rate of contaminant blood cultures could be reduced by using a team of dedicated phlebotomists. Comparisons were made between adult patients requiring blood cultures for suspected bacteremia on medical and surgical units before and after the introduction and withdrawal of a dedicated blood culture team. The results showed that a significant reduction in the contaminant blood culture rate was achieved by the blood culture team (P < 0.001; chi(2) test). Therefore, in our experience, the rate of contaminant blood cultures can be reduced in a teaching hospital by using a team of dedicated phlebotomists. Calculations made with our data and those published by others suggest that cost savings from reducing false-positive blood cultures are greater than the cost of the blood culture team.  相似文献   
6.
5-Amino-4-imidazolecarboxamide (AICA) riboside, the nucleoside corresponding to AICA ribotide (AICAR or ZMP), an intermediate of the de novo pathway of purine biosynthesis, was found to exert a dose-dependent inhibition on gluconeogenesis in isolated rat hepatocytes. Production of glucose from lactate-pyruvate mixtures was half-maximally inhibited by approximately 100 microM and completely suppressed by 500 microM AICA riboside. AICA riboside also inhibited the production of glucose from all other gluconeogenic precursors investigated, i.e., fructose, dihydroxyacetone, and L-proline. Measurements of intermediates of the glycolytic-gluconeogenic pathway showed that AICA riboside provoked elevations of triose phosphates and fructose-1,6-bisphosphate and decreases in fructose-6-phosphate and glucose-6-phosphate. The effects of AICA riboside persisted when the cells were washed 10 min after its addition but were suppressed by 5-iodotubercidin, an inhibitor of adenosine kinase. AICA riboside provoked a dose-dependent buildup of normally undetectable Z nucleotides. After 20 min of incubation with 500 microM AICA riboside, ZMP, ZTP, and ZDP reached 3, 0.3, and 0.1 mumol/g cells, respectively. Concentrations of ATP were not significantly modified by addition of up to 500 microM AICA riboside when the cells were incubated with lactate-pyruvate but decreased with fructose or dihydroxyacetone. The activity of rat liver fructose-1,6-bisphosphatase was inhibited by ZMP with an apparent Ki of 370 microM. It is concluded that AICA riboside exerts a suppressive effect on gluconeogenesis because it provokes an accumulation of ZMP, which inhibits fructose-1,6-bisphosphatase.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
7.
Ohne ZusammenfassungReferat.HerrBuhtz-Breslau berichtet über den Fall Wolff-Breslau. Die klar überlegte Mordtat des frühreifen Jugendlichen hatte den Anlaß zu dem Gesetz über jugendliche Schwerverbrecher gebildet.HerrRücker-Hamburg berichtet über einen Arzt, der das Opfer einer Hysterica geworden war. Bei einer erregten Auseinandersetzung hatte er die Frau mit dem ihr entrissenen und gegen ihn gezückten Dolch niedergestoßen und getötet. Der Täter hatte 18 Jahre unter fremdem Namen in China das große Hospital einer deutsch-evangelischen Mission geleitet. Nach Verurteilung zu 2 Jahren Gefängnis und erlangter Bewährungsfrist ist er nach China zurückgekehrt.  相似文献   
8.
9.
OBJECTIVES: Intraoperative cone-beam computerized tomography (CBCT) imaging has been introduced in oral and maxillofacial surgery. Using midfacial fractures as the pioneer model, this study describes the spectrum of further promising clinical indications for intraoperative CBCT and a clinical combination with intraoperative navigation. STUDY DESIGN: One hundred seventy-nine patients admitted for surgical treatment of the facial skeleton were included in the study. Intraoperatively, 3-dimensional images were generated with the mobile CBCT scanner Arcadis Orbic 3D, obtained from Siemens Medical Solutions, in a variety of indications. RESULTS: The acquisition of the data sets was uncomplicated, and image quality was sufficient to assess the postoperative result in all cases. In the example of a facial gunshot injury, a navigation system for intraoperative localization of the metal foreign bodies was used.  相似文献   
10.
Ohne Zusammenfassungfrüherem Assistenten des Instituts, jetzigem Assistenten an der chirurgischen Abteilung des Augusta-Hospitals, Berlin.Hierzu Taf. IV und 1 Textfigur.  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