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   1463篇
  免费   108篇
  国内免费   35篇
耳鼻咽喉   6篇
儿科学   77篇
妇产科学   20篇
基础医学   150篇
口腔科学   76篇
临床医学   177篇
内科学   299篇
皮肤病学   20篇
神经病学   59篇
特种医学   128篇
外科学   179篇
综合类   22篇
一般理论   2篇
预防医学   162篇
眼科学   10篇
药学   93篇
肿瘤学   126篇
  2021年   15篇
  2019年   16篇
  2018年   24篇
  2017年   13篇
  2016年   18篇
  2015年   19篇
  2014年   33篇
  2013年   51篇
  2012年   58篇
  2011年   49篇
  2010年   51篇
  2009年   61篇
  2008年   32篇
  2007年   55篇
  2006年   39篇
  2005年   32篇
  2004年   27篇
  2003年   33篇
  2002年   42篇
  2001年   28篇
  2000年   28篇
  1999年   49篇
  1998年   45篇
  1997年   40篇
  1996年   46篇
  1995年   37篇
  1994年   43篇
  1993年   28篇
  1992年   33篇
  1991年   29篇
  1990年   13篇
  1989年   47篇
  1988年   35篇
  1987年   29篇
  1986年   25篇
  1985年   32篇
  1984年   51篇
  1983年   32篇
  1982年   24篇
  1981年   19篇
  1980年   25篇
  1979年   17篇
  1978年   18篇
  1977年   16篇
  1976年   16篇
  1975年   14篇
  1974年   16篇
  1973年   10篇
  1967年   10篇
  1966年   10篇
排序方式: 共有1606条查询结果,搜索用时 15 毫秒
1.
Kim  SH; Chang  KH; Song  IC; Han  MH; Kim  HC; Kang  HS; Han  MC 《Radiology》1997,204(1):239
  相似文献   
2.
3.
4.
Laparoscopic repair/peritoneal toilet of perforated duodenal ulcer   总被引:13,自引:6,他引:7  
Summary Laparoscopic techniques have been refined to the point where exposure, haemostasis and tissue approximation by suture approach those obtained at open access surgery. We report a patient with acute perforation of an ulcer in the first part of the duodenum who was successfully treated by laparoscopic oversewing and omental patching. The clinical indications for contemplating use of laparoscopic surgery for acute ulcer perforation, techniques employed and the areas for potential improvement of instruments, needles and sutures are discussed.  相似文献   
5.
The effects of local tumor hyperthermia on regional lymph node metastases are inconclusive. We studied the effects of hyperthermia on the incidence of popliteal, femoral, and abdominal lymph node metastases in C57BL/6 mice with primary B16 melanomas (F10 variant) growing subcutaneously in the left foot. Tumors were heated to 42.3, 43.5, and 44.2 degrees C for 90 minutes either 7 days after inoculation of 5 X 10(4) viable cells (microscopic tumor = mic) or when the tumors were approximately 3 mm in diameter (macroscopic tumor = mac). Femoral lymph node metastases occurred in 0/21 control animals and in 8/22 (36%), 11/19 (58%), and 11/17 (65%) animals whose primary tumors were heated to 42.3, 43.5, and 44.2 degrees C, respectively. For all three treatments, the increase in metastases as compared to controls was statistically significant (p less than 0.004, Fisher's exact test). The incidence of abdominal lymph node metastasis was slightly higher in the treated groups than controls. Twenty of 21 (95%) control mice developed popliteal lymph node metastases and hyperthermia-induced increases could not be demonstrated. Fifteen of 21 control mice killed 3 weeks after amputation of tumor-containing leg had pulmonary metastases with an average of 6 +/- 4 (standard deviation) lesions per affected mouse. Pulmonary metastases occurred in 22/22 (100%), 17/19 (89%), and 13/17 (76%) of mice whose tumors were heated to 42.3, 43.5, and 44.2 degrees C, respectively. The numbers of metastases for affected mice were significantly increased compared to controls for tumors heated to 43.5 and 44.2 degrees C (28 +/- 43, 43 +/- 52, 119 +/- 121, p greater than 0.02, p less than 0.006, p less than 0.002, for two sample T-test). While 0/8 mic tumors were cured 5/9 mac tumors heated to 44.2 degrees C disappeared (p less than 0.03, Fisher's exact test) and there was a growth delay in the remaining mice. Mic tumors, heated to 43.5 degrees C, had an accelerated onset of growth while mac tumors heated to this temperature had a slight growth delay. Growth of both mic and mac primary tumors heated to 42.3 degrees C was similar to controls. These results show that therapeutic and subtherapeutic local hyperthermia increases metastases to regional lymph nodes and to lungs even when primary tumor growth rate is partially or totally controlled.  相似文献   
6.
Retention of restorations cemented with temporary cement varies. Some cements are adhesive and others are weak in retention. In addition, cement retention may vary over time. This study determined (1) the retentive properties of four temporary cements, and (2) the effects of aging on temporary cement retention. Cylindrical amalgam cores and mated stainless steel retainers with a 0.05 mm cement space were used in the study. Cores were cemented into the retainers and stored in 100% humidity at 37 degrees C until tested. Retention was measured by applying a compressive force to the cores through a rod in an Instron machine. Half the samples were tested after 1 week and half were tested after 6 weeks. The results indicate a significant difference in retentive value among the four cements, including a significant decrease in retention for one cement over the 6-week aging period.  相似文献   
7.
Cerebral single photon emission computed tomography (SPECT), a method of functional brain imaging, measures cerebral blood flow and metabolism. This paper describes the imaging procedure and several cases where cerebral SPECT was of use in the differential diagnosis of medically ill patients who also presented with psychopathology. SPECT patterns in cerebrovascular disease, dementia, focal epilepsy, and AIDS are at present the best described and seem to be the most specific. Often changes in regional cerebral blood flow are seen before structural changes become apparent on CT or MRI. Cerebral SPECT can add valuable diagnostic information in assessing psychopathology in the medically ill and can often lead to changes in treatment.  相似文献   
8.
We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.  相似文献   
9.
10.
A technique for laparoscopic reduction, crural repair, and total fundoplication for large symptomatic hiatal hernia is described. The procedure entails the mobilization of the esophagogastric junction with crural repair by a continuous suture technique employing a special pre-formed jamming loop knot, followed by total fundoplication that is fixed proximally to the anterior margin of the diaphragmatic hiatus and distally to the esophagogastric junction. The procedure has been performed in eight elderly patients with a good outcome and accelerated recovery to full activity.  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