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   3051篇
  免费   153篇
  国内免费   8篇
耳鼻咽喉   15篇
儿科学   87篇
妇产科学   121篇
基础医学   374篇
口腔科学   21篇
临床医学   227篇
内科学   818篇
皮肤病学   24篇
神经病学   286篇
特种医学   85篇
外科学   296篇
综合类   8篇
一般理论   1篇
预防医学   229篇
眼科学   55篇
药学   189篇
中国医学   7篇
肿瘤学   369篇
  2023年   10篇
  2022年   29篇
  2021年   64篇
  2020年   34篇
  2019年   58篇
  2018年   65篇
  2017年   56篇
  2016年   64篇
  2015年   59篇
  2014年   96篇
  2013年   139篇
  2012年   213篇
  2011年   217篇
  2010年   118篇
  2009年   105篇
  2008年   194篇
  2007年   168篇
  2006年   173篇
  2005年   168篇
  2004年   174篇
  2003年   110篇
  2002年   154篇
  2001年   62篇
  2000年   75篇
  1999年   56篇
  1998年   28篇
  1997年   26篇
  1996年   21篇
  1995年   16篇
  1994年   24篇
  1993年   17篇
  1992年   39篇
  1991年   27篇
  1990年   33篇
  1989年   29篇
  1988年   26篇
  1987年   23篇
  1986年   26篇
  1985年   16篇
  1984年   14篇
  1983年   10篇
  1982年   17篇
  1980年   10篇
  1979年   19篇
  1977年   12篇
  1975年   9篇
  1974年   11篇
  1973年   9篇
  1969年   12篇
  1965年   9篇
排序方式: 共有3212条查询结果,搜索用时 328 毫秒
91.
92.
93.
Neurological Sciences - Few epidemiological studies have assessed the risk of parkinsonisms after prolonged use of neuroleptics. We aimed to examine the long-term risk of degenerative parkinsonisms...  相似文献   
94.

Purpose

The distinction between cut marks and blunt force injuries on costal cartilages is a crucial issue in the forensic field. Moreover, a correct distinction may further be complicated by decomposition, so the need arises to investigate the distinctive features of lesions on cartilage and their changes over time.

Methods

This study aimed to assess the stereomicroscopic features of cut marks (performed with six different knives) and blunt fractures (performed with a hammer and by means of manual bending) on 48 fragments of human costal cartilages. Moreover, in order to simulate decomposition, the cut and fractured surfaces were checked with stereomicroscopy and through casts after 1 and 2 days, 1 week, and 1, 2 and 4 months of drying in ambient air.

Results

In fresh samples, for single and unique cuts, striations were observed in between 44 and 88 % of cases when non-serrated blades were used, and between 77 and 88 % for serrated blades; in the case of “repeated” (back and forth movement) cuts, striations were detected in between 56 and 89 % of cases for non-serrated blades, and between 66 and 100 % for serrated blades. After only 1 week of decomposition the detection rates fell to percentages of between 28 and 39 % for serrated blades and between 17 and 33 % for non-serrated blades. Blunt force injuries showed non-specific characteristics, which, if properly assessed, may lead to a reliable distinction between different cut marks in fresh samples. The most evident alterations of the structure of the cartilage occurred in the first week of decomposition in ambient air. After one week of drying, the characteristics of cut marks were almost undetectable, thereby making it extremely challenging to distinguish between cut marks, blunt force fractures and taphonomic effects.

Conclusion

The study represents a contribution to the correct assessment and distinction of cut marks and blunt force injuries on cartilages, providing a glimpse on the modifications such lesions may undergo with decomposition.
  相似文献   
95.
96.

Aim

Surgical myotomy of the lower esophageal sphincter has a 5-year success rate of approximately 91 %. Peroral endoscopic myotomy can provide similar results for controlling dysphagia. Some patients experience either persistent or recurrent dysphagia after myotomy. We present here a retrospective analysis of our experience with redo myotomy for recurrent dysphagia in patients with achalasia.

Methods

From March 1996 to February 2015, 234 myotomies for primary or recurrent achalasia were performed in our center. Fifteen patients (6.4 %) had had a previous myotomy and were undergoing surgical redo myotomy (n?=?9) or endoscopic redo myotomy (n?=?6) for recurrent symptoms.

Results

Patients presented at a median of 10.4 months after previous myotomy. Median preoperative Eckardt score was 6. Among the nine patients undergoing surgical myotomy, three esophageal perforations occurred intraoperatively (all repaired immediately). Surgery lasted 111 and 62 min on average (median) in the surgical and peroral endoscopic myotomy (POEM) groups, respectively. No postoperative complications occurred in either group. Median postoperative stay was 3 and 2.5 days in the surgical and POEM groups, respectively. In the surgical group, Eckardt score was <3 for seven out of nine patients after a mean follow-up of 19 months; it was <3 for all six patients in the POEM group after a mean follow-up of 5 months.

Conclusions

A redo myotomy should be considered in patients who underwent myotomy for achalasia and presenting with recurrent dysphagia. Preliminary results using POEM indicate that the technique can be safely used in patients who have undergone previous surgical myotomy.
  相似文献   
97.
Functional magnetic resonance imaging (fMRI) is used to distinguish areas of the brain responsible for different tasks and functions. It is possible, for example, by using fMRI images, to identify particular regions in the brain which can be considered as "functional organs at risk" (fOARs), i.e., regions which would cause significant patient morbidity if compromised. The aim of this study is to propose and validate a method to exploit functional information for the identification of fOARs in CyberKnife (Accuray, Inc., Sunnyvale, CA) radiosurgery treatment planning; in particular, given the high spatial accuracy offered by the CyberKnife system, local nonrigid registration is used to reach accurate image matching. Five patients affected by arteriovenous malformations (AVMs) and scheduled to undergo radiosurgery were scanned prior to treatment using computed tomography (CT), three-dimensional (3D) rotational angiography (3DRA), T2 weighted and blood oxygenation level dependent echo planar imaging MRI. Tasks were chosen on the basis of lesion location by considering those areas which could be potentially close to treatment targets. Functional data were superimposed on 3DRA and CT used for treatment planning. The procedure for the localization of fMRI areas was validated by direct cortical stimulation on 38 AVM and tumor patients undergoing conventional surgery. Treatment plans studied with and without considering fOARs were significantly different, in particular with respect to both maximum dose and dose volume histograms; consideration of the fOARs allowed quality indices of treatment plans to remain almost constant or to improve in four out of five cases compared to plans with no consideration of fOARs. In conclusion, the presented method provides an accurate tool for the integration of functional information into AVM radiosurgery, which might help to minimize undesirable side effects and to make radiosurgery less invasive.  相似文献   
98.
Lasers in Medical Science - The benefits of photobiomodulation (PBM) applied to wounds are well-described in the literature; however, its effects in skin graft donor sites have been poorly studied....  相似文献   
99.

Introduction  

It has been shown that early central venous oxygen saturation (ScvO2)-guided optimization of hemodynamics can improve outcome in septic patients. The early ScvO2 profile of other patient groups is unknown. The aim of this study was to characterize unplanned admissions in a multidisciplinary intensive care unit (ICU) with respect to ScvO2 and outcome.  相似文献   
100.
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