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   2317篇
  免费   182篇
  国内免费   1篇
耳鼻咽喉   22篇
儿科学   43篇
妇产科学   51篇
基础医学   348篇
口腔科学   32篇
临床医学   297篇
内科学   528篇
皮肤病学   56篇
神经病学   177篇
特种医学   141篇
外国民族医学   1篇
外科学   200篇
综合类   41篇
预防医学   196篇
眼科学   9篇
药学   237篇
中国医学   1篇
肿瘤学   120篇
  2023年   9篇
  2022年   12篇
  2021年   36篇
  2020年   39篇
  2019年   36篇
  2018年   62篇
  2017年   38篇
  2016年   38篇
  2015年   41篇
  2014年   75篇
  2013年   107篇
  2012年   111篇
  2011年   137篇
  2010年   91篇
  2009年   83篇
  2008年   96篇
  2007年   105篇
  2006年   96篇
  2005年   90篇
  2004年   91篇
  2003年   89篇
  2002年   98篇
  2001年   59篇
  2000年   64篇
  1999年   68篇
  1998年   38篇
  1997年   32篇
  1996年   47篇
  1995年   40篇
  1994年   41篇
  1993年   39篇
  1992年   51篇
  1991年   45篇
  1990年   28篇
  1989年   41篇
  1988年   30篇
  1987年   20篇
  1986年   22篇
  1985年   25篇
  1984年   20篇
  1983年   18篇
  1982年   17篇
  1981年   11篇
  1980年   15篇
  1979年   18篇
  1978年   14篇
  1977年   11篇
  1957年   9篇
  1949年   8篇
  1948年   8篇
排序方式: 共有2500条查询结果,搜索用时 31 毫秒
41.
42.
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   
43.
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   
44.
45.
Resection margins are frequently studied in patients with oral squamous cell carcinoma and are accepted as a constant prognostic factor. While most evidence is based on soft tissue margins, reported data for bone resection margins are scarce. The aim of this retrospective study was to evaluate and determine the utility of surgical margins in bone resections for oral cavity squamous cell carcinoma (OCSCC). The status of bone resection margins and their impact on survival was investigated in patients who had undergone segmental mandibulectomy for OCSCC. Medical records were retrieved for the years 2000–2012; 127 patients were identified and included in the study. Tumour-positive bone resection margins were found in 21% of the patients. The 5-year overall survival was significantly lower in this group (P < 0.005). Therefore, there is a need for intraoperative feedback on the status of bone resection margins to enable immediate additional resection where necessary. Although the lack of intraoperative methods for the evaluation of bone tissue has been addressed by many authors, there is still no reliable method for widespread use. Future research should focus on an objective, accurate, and rapid method of intraoperative assessment for the entire bone resection margin to optimize patient outcomes.  相似文献   
46.
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   
47.
48.
49.
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   
50.
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