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   3689篇
  免费   330篇
  国内免费   10篇
耳鼻咽喉   52篇
儿科学   36篇
妇产科学   46篇
基础医学   472篇
口腔科学   128篇
临床医学   340篇
内科学   844篇
皮肤病学   29篇
神经病学   245篇
特种医学   177篇
外科学   558篇
综合类   67篇
一般理论   10篇
预防医学   405篇
眼科学   30篇
药学   389篇
中国医学   3篇
肿瘤学   198篇
  2023年   11篇
  2022年   39篇
  2021年   57篇
  2020年   43篇
  2019年   58篇
  2018年   79篇
  2017年   71篇
  2016年   70篇
  2015年   97篇
  2014年   107篇
  2013年   156篇
  2012年   272篇
  2011年   318篇
  2010年   161篇
  2009年   161篇
  2008年   222篇
  2007年   283篇
  2006年   264篇
  2005年   261篇
  2004年   219篇
  2003年   234篇
  2002年   176篇
  2001年   57篇
  2000年   39篇
  1999年   43篇
  1998年   54篇
  1997年   29篇
  1996年   29篇
  1995年   27篇
  1994年   25篇
  1993年   25篇
  1992年   25篇
  1991年   29篇
  1990年   23篇
  1989年   25篇
  1988年   19篇
  1987年   16篇
  1986年   19篇
  1985年   21篇
  1984年   20篇
  1983年   15篇
  1982年   11篇
  1981年   9篇
  1980年   11篇
  1977年   12篇
  1976年   10篇
  1974年   10篇
  1973年   6篇
  1972年   6篇
  1968年   7篇
排序方式: 共有4029条查询结果,搜索用时 15 毫秒
1.

Aim

Tracheomalacia is flaccidity of the tracheal wall leading to tracheal collapse, particularly on expiration. When severe it can warrant surgical intervention. Aortopexy is one surgical option and has been described using a variety of approaches. We report outcomes of aortopexy performed via a suprasternal incision in a single centre by a single surgeon.

Methods

All patients undergoing aortopexy between February 2016 and May 2018 were prospectively included. Patients were managed by a multi-disciplinary team (MDT) and underwent standardized work-up, including dynamic flexible bronchoscopy (DFB) and contrast enhanced CT. Aortopexy was performed via a suprasternal skin crease incision. Surgery was guided by intra-operative flexible bronchoscopy. Data regarding pre-operative symptoms, degree of tracheomalacia, and outcomes were recorded.

Results

Twenty-two patients were included, 18 boys, median age 5?months (range 1?month–5?years). Two aortopexy sutures were used in all cases, and three patients required an additional tracheopexy suture. Median operating time was 1?h 24?min (range 47?min–2?h 35?min). Median pre-operative tracheal collapse on DFB was 85% (range 80–95%), improving to 35% (35–80%) intra-operatively. Median length of stay was 4?days (range 1–118).

Conclusions

Aortopexy via a suprasternal incision is a useful treatment modality for tracheomalacia with short operating times and rapid recovery. Outcomes vary with the best results in the TOF and premature groups. Careful patient selection and MDT work-up are essential to optimize outcomes.

Level of Evidence

Level 3 (Case Series).  相似文献   
2.
Plasma viscosity, molecular markers of activated coagulation and fibrinolysis (fibrinopeptides A and B beta 15-42), coagulation factors (fibrinogen and factor VII) and antiplasmins were measured in 529 men aged 35-54 years and related to new angina pectoris (n = 117) and to coronary risk factors in controls without angina (n = 412). Five major risk factors (cigarette-smoking, blood pressure, cholesterol, triglyceride and body mass index) were each associated with increases in plasma viscosity, coagulation factors, and imbalance of coagulation over fibrinolysis (increased ratio of fibrinopeptide A/fibrinopeptide B beta 15-42). Increased viscosity and fibrinogen in smokers were partly reversed in ex-smokers, but the imbalance of coagulation and fibrinolysis persisted. Cholesterol and triglyceride were also associated with increased antiplasmin activity. In men with angina, only fibrinogen was elevated compared to controls. We suggest that increased plasma viscosity and an imbalance of coagulation over fibrinolysis may be mechanisms by which known risk factors promote arterial thrombosis, but are not present in stable angina.  相似文献   
3.
4.
5.
In cases of cerebrospinal fluid (CSF) rhinorrhea following lateral skull base surgery, fibrosis and fibrin formation resulting from meningitis has been postulated as a mechanism of spontaneously resolving the CSF leak. This study was undertaken to explore any possible relationship between the cessation of CSF leak and meningitis. A retrospective study at a tertiary referral center of 232 consecutive patients was performed. Out of a total of 232 procedures, 29 patients developed CSF rhinorrhea, of whom 7 subsequently developed meningitis. Bacteria were isolated in CSF obtained at lumbar puncture in 5 cases, with the CSF analysis in the remaining 2 cases suggesting aseptic meningitis. Conservative treatment failed to stop the CSF rhinorrhea in 6 of 7 cases. In this study, the development of meningitis did not appear to aid in the resolution of the CSF rhinorrhea. We conclude that surgical intervention should not be delayed in the expectation that meningitis and conservative interventions may promote CSF leak resolution.  相似文献   
6.
7.
1. The effect of inflammation induced by lipopolysaccharide (LPS) injection on plasma follistatin (FS) concentrations was investigated. 2. Plasma FS and tumour necrosis factor-α concentrations increase following LPS administration in ewes. 3. The rise in FS is similar, but more sustained, to that previously observed after surgery. 4. These results indicate a possible functional link between FS, inflammation and the acute-phase response.  相似文献   
8.
A 75 year old woman with a 13 year history of classical chronic lymphatic leukaemia (CLL) developed hypercalcaemia. Unlike previous reports, this was not associated with blastic transformation, hyperparathyroidism or features of multiple myeloma, but was due to classical CLL per se.  相似文献   
9.
BACKGROUND: Previous structural magnetic resonance (MR) research in patients with posttraumatic stress disorder (PTSD) has found smaller hippocampal volumes in patients compared with control subjects. These studies have mostly involved subjects who have had PTSD for a number of years, such as war veterans or adult survivors of childhood abuse. Patients with recent-onset PTSD have rarely been investigated. To our knowledge only one other study has investigated such a group. The aim of this study was to compare hippocampal volumes of patients with recent onset PTSD and nontrauma-exposed control subjects. METHODS: Fifteen patients with PTSD, recruited from an accident and emergency department, were compared with 11, non-trauma-exposed, healthy control subjects. Patients underwent a structural MR scan soon after trauma (mean time = 158 +/- 41 days). Entire brain volumes, voxel size 1 x 1 x 1 mm, were acquired for each subject. Point counting and stereology were used to measure the hippocampal and amygdala volume of each subject. RESULTS: Right-sided hippocampal volume was significantly smaller in PTSD patients than control subjects after controlling for effects of whole brain volume and age. Neither left nor total hippocampal volume were significantly smaller in the PTSD group after correction. Whole brain volume was also found to be significantly smaller in patients. There were no differences in amygdala or white matter volumes between patients and control subjects. CONCLUSIONS: This result replicates previous findings of smaller hippocampal volumes in PTSD patients, but in an underinvestigated population, suggesting that either smaller hippocampal volume is a predisposing factor in the development of PTSD or that damage occurs within months of trauma, rather than a number of years. Either of these two hypotheses have significant implications for the treatment of PTSD. For instance, if it could be shown that screening for hippocampal volume may, in some cases, predict those likely to develop clinical PTSD.  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