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   1220篇
  免费   56篇
  国内免费   1篇
耳鼻咽喉   6篇
儿科学   40篇
妇产科学   53篇
基础医学   145篇
口腔科学   23篇
临床医学   161篇
内科学   259篇
皮肤病学   38篇
神经病学   77篇
特种医学   106篇
外国民族医学   1篇
外科学   130篇
综合类   61篇
一般理论   4篇
预防医学   70篇
眼科学   6篇
药学   47篇
中国医学   1篇
肿瘤学   49篇
  2022年   20篇
  2021年   24篇
  2020年   11篇
  2019年   20篇
  2018年   20篇
  2017年   17篇
  2016年   15篇
  2015年   25篇
  2014年   31篇
  2013年   50篇
  2012年   24篇
  2011年   34篇
  2010年   47篇
  2009年   40篇
  2008年   31篇
  2007年   29篇
  2006年   28篇
  2005年   25篇
  2004年   25篇
  2003年   31篇
  2002年   34篇
  2001年   21篇
  2000年   30篇
  1999年   17篇
  1998年   25篇
  1997年   18篇
  1996年   27篇
  1995年   22篇
  1994年   29篇
  1993年   30篇
  1992年   34篇
  1991年   23篇
  1990年   16篇
  1989年   34篇
  1988年   32篇
  1987年   15篇
  1986年   17篇
  1985年   24篇
  1983年   16篇
  1982年   12篇
  1981年   14篇
  1980年   16篇
  1979年   22篇
  1978年   14篇
  1977年   21篇
  1976年   10篇
  1975年   10篇
  1973年   12篇
  1969年   9篇
  1957年   9篇
排序方式: 共有1277条查询结果,搜索用时 187 毫秒
21.
Epilepsy surgery has emerged as an important option in the treatment of children with epilepsy that is refractory to antiepileptic drug management. The cornerstone of successful surgery is accurate localization of the brain region of seizure onset. Traditional techniques of seizure onset localization, e.g. surface electroencephalography (EEG) recording and magnetic resonance imaging (MRI), allow accurate localization in a significant number of patients. When the focus of seizure onset is not apparent from these non-invasive techniques, other methods of localization, e.g. intracranial EEG recording, may be needed before resection of the focus. Single-photon emission computed tomography (SPECT) is a nuclear medicine blood-flow technique that has been used to identify a region of epileptogenic brain associated with low blood flow in the resting state (interictal SPECT) or increased blood flow at the time of seizure activity (ictal SPECT). This report describes the validation and utility of a computer-assisted method of subtracting the interictal from the ictal SPECT scans and co-registering the difference image on the MRI. This method, called subtraction ictal SPECT co-registered on MRI (SISCOM), is used in guiding the location and the extent of intracranial electrode implantation, or in obviating the need for the implantation in some cases.  相似文献   
22.
Female circumcision is a traditional practice common in African countries. It involves partial or total removal of external female genitalia. It has led to many complications, in particular, the scarring of the external genitalia. The consequence is a very narrow introitus making the intracavitary brachytherapy treatment component difficult when these women develop cancer of cervix. We present two such cases from our institution. Our aim is to make the radiation and gynecological oncologists, both in developed and developing countries, aware of this practice and the problems they can encounter in the management of such cases. Intracavitary brachytherapy is an important component in the potentially curative role of radiation therapy for cervical cancer. Every effort should be made to ensure that the sequelae of genital mutilation does not deprive these women of the same standard of care as the general population.  相似文献   
23.
24.
25.
For some patients with radiculopathy a source of nerve root compression cannot be identified despite positive electromyography (EMG) evidence. This discrepancy hampers the effective clinical management for these individuals. Although it has been well-established that tissues in the cervical spine move in a three-dimensional (3D) manner, the 3D motions of the neural elements and their relationship to the bones surrounding them are largely unknown even for asymptomatic normal subjects. We hypothesize that abnormal mechanical loading of cervical nerve roots during pain-provoking head positioning may be responsible for radicular pain in those cases in which there is no evidence of nerve root compression on conventional cervical magnetic resonance imaging (MRI) with the neck in the neutral position. This biomechanical imaging proof-of-concept study focused on quantitatively defining the architectural relationships between the neural and bony structures in the cervical spine using measurements derived from 3D MR images acquired in neutral and pain-provoking neck positions for subjects: (1) with radicular symptoms and evidence of root compression by conventional MRI and positive EMG, (2) with radicular symptoms and no evidence of root compression by MRI but positive EMG, and (3) asymptomatic age-matched controls. Function and pain scores were measured, along with neck range of motion, for all subjects. MR imaging was performed in both a neutral position and a pain-provoking position. Anatomical architectural data derived from analysis of the 3D MR images were compared between symptomatic and asymptomatic groups, and the symptomatic groups with and without imaging evidence of root compression. Several differences in the architectural relationships between the bone and neural tissues were identified between the asymptomatic and symptomatic groups. In addition, changes in architectural relationships were also detected between the symptomatic groups with and without imaging evidence of nerve root compression. As demonstrated in the data and a case study the 3D stress MR imaging approach provides utility to identify biomechanical relationships between hard and soft tissues that are otherwise undetected by standard clinical imaging methods. This technique offers a promising approach to detect the source of radiculopathy to inform clinical management for this pathology.  相似文献   
26.
See also Lowe GDO. Epidemiology of venous thromboembolism: the need for large (including prospective) studies and meta‐analyses. This issue, pp 2186–8 and Rosendaal FR. Etiology of venous thrombosis: the need for small original studies. This issue, pp 2189–90.  相似文献   
27.
ObjectivesThe aim of the present study is to evaluate the feasibility and safety of performing PNL under local anesthesia in a selected group of patients who are at high risk for general anesthesia.Patients and methodsForty seven patients underwent PNL under local anesthesia. There were 38 males and 9 females with a mean age of 62 years. All patients were at medical high-risk for general anesthesia, with an American Society of Anesthesiologists (ASA) score of 3. The indications for local anesthesia in this study were obstructed single functioning kidney with azotemia in 29 patients, hepatic insufficiency in 8 patients, cardiac problems in 7 patients and 3 patients had hepatocellular carcinoma. The mean stone size was 2.7 cm (range 2–3.1 cm). Local infiltration with 10–20 cc of 2% lidocaine at the site of puncture was used in all cases. Narcotics were given 30 min prior to the procedure and medazolam was given intraoperatively upon demand. Utrasound guided puncture was performed in all cases and tract dilatation was then done under fluoroscopy using high pressure balloon catheter in 35 and Alken's metal dilators in 12 cases. Stones were then retrieved after disintegration in the same cession in 33 patients, while the other 14 patients underwent staged PNL, where a 12 Fr. nephrostomy tube was placed in the first stage, followed by tract dilatation and stone retrieval one week later.ResultsOut of 47 patients included, 44 had successful PNL either one stage (30 patients) or two stages (14 patients). Only 3 patients could not tolerate pain and the procedure was terminated after placement of nephrostomy tube and stone retrieval was completed later under general anesthesia.ConclusionOur results demonstrated that PNL under local anesthesia with narcotics and sedatives seems to be a satisfying solution for the treatment of a selected group of patients with renal pelvic stones and who have high anesthetic risk. However, additional studies with different groups of patients are required to validate our results.  相似文献   
28.
Die Anaesthesiologie - Der Postpunktionskopfschmerz („postdural puncture headache“, PDPH) zählt zu den wesentlichen Komplikationen der peripartalen neuroaxialen Analgesie. Als...  相似文献   
29.
30.
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