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   1582篇
  免费   71篇
  国内免费   11篇
耳鼻咽喉   54篇
儿科学   126篇
妇产科学   57篇
基础医学   129篇
口腔科学   107篇
临床医学   173篇
内科学   309篇
皮肤病学   69篇
神经病学   96篇
特种医学   77篇
外科学   225篇
综合类   23篇
预防医学   30篇
眼科学   33篇
药学   80篇
中国医学   3篇
肿瘤学   73篇
  2024年   2篇
  2023年   18篇
  2022年   18篇
  2021年   44篇
  2020年   21篇
  2019年   51篇
  2018年   37篇
  2017年   31篇
  2016年   56篇
  2015年   65篇
  2014年   85篇
  2013年   98篇
  2012年   123篇
  2011年   130篇
  2010年   77篇
  2009年   60篇
  2008年   125篇
  2007年   138篇
  2006年   129篇
  2005年   107篇
  2004年   94篇
  2003年   85篇
  2002年   35篇
  2001年   14篇
  2000年   6篇
  1999年   5篇
  1998年   4篇
  1997年   3篇
  1996年   1篇
  1995年   1篇
  1993年   1篇
排序方式: 共有1664条查询结果,搜索用时 15 毫秒
21.

Objectives

Confirmation of the endotracheal tube placement (CoETP) has the utmost importance in the management of an airway. Visualization of tracheal rings or carina with a fiber-optical bronchoscope (FOB) has considered to be a reliable method for the CoETP. However, FOB is expensive, time-consuming, and not always practical. Inexpensive endoscopic USB-cameras were shown to aid intubation successfully and reliably. On the other hand, there have been no studies investigating their use for the CoETP. Tracheal ultrasonography (TUS) is also a new, inexpensive and widely available alternative. A cadaver study has planned to evaluate the diagnostic utility of TUS and a USB-camera.

Methods

This study was conducted in the Anatomy Lab of a University on a fresh frozen female cadaver. Three senior Emergency Physicians have intubated the cadaver, and performed TUS or USB-endoscopy. We have prepared a randomized intubation list (n = 96) in three blocks (3 times 32) as to include equal number of esophageal and tracheal intubations (48 for each). Each EP is performed all three interventions (intubation, TUS and USB-endoscopy) in consecutive blocks of 32 intubations, in turn. The position of the tube has been verified from a 2 cm wide ostium on the proximal trachea.

Results

In this study, all intubations (n = 96, 100%) were correctly identified as tracheal or esophageal with both TUS and USB-camera. Both the sensitivity and specificity of TUS and USB-endoscopy for the CoETP were 100.0%.

Conclusion

The perfect accuracy of TUS and USB-endoscopy, have placed those techniques in a unique position as an alternative in resource-poor situations.  相似文献   
22.

Introduction

The diagnostic accuracy of the FAST exam performed by EM residents were shown to be similar to radiology residents. However, in the last 2 decades, an extended-FAST (E-FAST) protocol including thoracic examination to exclude pneumo- and hemothorax was introduced. The accuracy of emergency physicians (EPs) while performing E-FAST is a less studied area, especially in Europe. The aim of this study was to compare the diagnostic accuracy of the E-FAST exam performed by EM residents with the results of CT scan as a gold standard.

Methods

This was a prospective, observational, diagnostic accuracy study conducted at the ED of a Level 1 Trauma Center. All consecutive adult multiple trauma patients were eligible, and any patient in whom thoraco-abdominal CT was ordered were recruited. Unstable and unavailable patients were excluded. E-FAST examination was performed by EPs as the index test, and CT examinations reported by a blinded academic radiology faculty was the gold standard.

Results

A total of 140 patients were recruited from eligible 144 patients. The final study population was 132 for abdominal and 130 for thorax examinations. In this study, AUC of E-FAST was 0.71 for abdominal free fluid, 0.87 for pneumothorax and 1.00 for pleural effusion. The sensitivity was 42.9% and specificity was 98.4%. The + LR for abdominal free fluid was 26.8 and ? LR was 0.58.

Conclusion

E-FAST examination has an excellent specificity. However, the sensitivity of the test is not high enough to rule-out thoraco-abdominal injuries in trauma patients when performed by EPs.  相似文献   
23.
24.
AIM: To evaluate the neuroprotective activity of systemically administered edaravone in early and late stage of experimental glaucoma in rats. METHODS: In this study, 60 Wistar albino rats were used. Experimental glaucoma model was created by injecting hyaluronic acid to the anterior chamber once a week for 6wk in 46 of 60 subjects. Fourteen subjects without any medication were included as control group. Edaravone administered intraperitoneally 3 mg/kg/d to the 15 of 30 subjects starting at the onset of glaucoma induction and also administered intraperitoneally 3 mg/kg/d to the other 15 subjects starting at three weeks after the onset of glaucoma induction. The other 16 subjects who underwent glaucoma induction was administered any therapy. Retinal ganglion cells (RGCs) have been marked with dextran tetramethylrhodamine (DTMR) retrograde at the end of the sixth week and after 48h, subjects were sacrificed by the method of cardiac perfusion. Alive RGC density was assessed in the whole-mount retina. Whole-mount retinal tissues homogenized and nitric oxide (NO), malondialdehyde (MDA) and total antioxidant capacity (TAC) values were measured biochemically. RESULTS: RGCs counted with Image-Pro Plus program, in the treatment group were found to be statistically significantly protected, compared to the glaucoma group (Bonferroni, P<0.05). The neuroprotective activity of edaravone was found to be more influential by administration at the start of the glaucoma process. Statistically significant lower NO levels were determined in the glaucoma group comparing treatment groups (Bonferroni, P<0.05). MDA levels were found to be highest in untreated glaucoma group, TAC levels were found to be lower in the glaucoma induction groups than the control group (Bonferroni, P<0.05). CONCLUSION: Systemic administration of Edaravone in experimental glaucoma showed potent neuroprotective activity. The role of oxidative stress causing RGC damage in glaucoma was supported by this study results.  相似文献   
25.
Clinical Rheumatology - Autoimmune pancreatitis (AIP) type 1 is an IgG4-related disease (IgG4-RD), characterized by inflammatory pseudotumors and histologically by dense lymphoplasmacytic...  相似文献   
26.
Objectives: The aim of this study was to assess B‐mode and power Doppler ultrasound findings of long head of biceps tendon in patients with ankylosing spondylitis (AS). Methods: Anthropometric measurements were carried out and disease activity and functional status were evaluated with BASDAI, BASFI, Dougados Functional Index (DFI) and Articular Index (DAI) in 30 patients with AS. The Shoulder Disability Questionnaire (SDQ) was performed. Pressure pain threshold (PPT) was measured on bilateral long head of biceps tendon and B‐mode and power Doppler ultrasound were carried out. Focal changes (hypoechogenic areas within the tendon), calcification of the tendon, and fluid collection inside or outside the tendon sheath at bicipital groove (peritendinous hypoechoic rim) and vascularity of the peritendinous region were assessed. A cumulative ultrasound score (CUSS) was obtained. Results: Focal changes were present in five tendons of four patients. Calcification of the tendon was present in three tendons of three patients. Biceps tendon sheath effusion (peritendinous hypoechoic rim) was observed in 10 tendons of eight patients. Thirteen tendons of eight patients had discernible flow signals, six were inside the tendon sheath (within the hypoechoic rim) and seven were outside the tendon sheath. Cumulative US score correlated significantly with DFI and ESR. There was not a significant correlation between CUSS and total PPT. Conclusion: Ultrasound examination of the long head of biceps tendon gives detailed information of the tendon and PDUS has the potential to be able to show inflammatory activity of the tendon.  相似文献   
27.
BackgroundRib fractures are the most common complications of blunt chest trauma (BCT). Computed tomography (CT) is the modality of choice for BCT, but with several disadvantages. Ultrasonography (US) is an inexpensive, readily available, and relatively harmless imaging alternative. However, a direct comparison of the sonographic evaluation of the rib as a whole with CT as a reference has not been performed to date.ObjectiveThis study aimed to compare the diagnostic accuracy of US with CT for the detection of rib fractures in patients who presented to emergency department (ED) with BCT.MethodsWe included a convenience sample of adult patients who presented to the ED with thoracic pain after BCT in the last 24 h in this prospective, observational, diagnostic accuracy study. The diagnostic utility of US performed by an emergency physician was compared with thorax CT.ResultsThe final study population included 145 patients. The diagnostic accuracy of US was 80% with a sensitivity of 91.2% and specificity of 72.7% for the detection of any rib fracture (positive likelihood ratio 3.4 and negative likelihood ratio 0.12). If we considered each rib separately, the sensitivity of US decreased to 76.7% and specificity increased to 82.7% (81.3% accuracy).ConclusionsA negative US of the site of the highest tenderness and neighboring ribs in a patient with BCT who presented to the ED with lateralizing pain decreases the possibility of a rib fracture significantly. However, a positive US performs poorly to specify the exact location and number of the fractured ribs.  相似文献   
28.
29.
30.
[Purpose] Although oxidative stress is known to be present in rheumatoid arthritis (RA), the effects of exercise on oxidative parameters are unknown. The aim of this study was to investigate the effects of acute aerobic exercise on serum oxidant and antioxidant levels in patients with RA. [Subjects and Methods] Sixteen patients with RA and 10 age-matched healthy volunteers participated in this study. All participants wore polar telemeters and walked on a treadmill for 30 minutes at a speed eliciting 60–75% of maximal heart rates. Blood samples were obtained before, immediately and 24 hours after exercise and malondialdehyde (MDA) and total sulfhydrile group (RSH) levels were measured. [Results] Both groups had similar heart rates during the test but the treadmill speed of the RA patients was significantly lower than that of the healthy volunteers. Serum MDA levels were lower than in both groups immediately after exercise, with greater decrements in the RA patients than controls. MDA levels returned to baseline 24 hours after the exercise only in the controls; they remained low in the RA patients. There was a slight increase in serum RSH levels after exercise compared to baseline in both groups. [Conclusion] Moderate intensity treadmill exercise did not have any adverse effect on the oxidant-antioxidant balance. The results suggest that such an exercise may be safely added to the rehabilitation program of RA for additional antioxidant effects. Morever, this antioxidant environment is maintained longer in RA patients.Key words: Aerobic exercise, Oxidative status, Rheumatoid arthritis  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