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   433篇
  免费   23篇
  国内免费   18篇
耳鼻咽喉   1篇
儿科学   22篇
妇产科学   6篇
基础医学   43篇
口腔科学   10篇
临床医学   54篇
内科学   96篇
皮肤病学   3篇
神经病学   8篇
特种医学   131篇
外科学   17篇
综合类   11篇
预防医学   14篇
眼科学   3篇
药学   23篇
肿瘤学   32篇
  2023年   1篇
  2022年   1篇
  2021年   4篇
  2020年   2篇
  2019年   1篇
  2018年   5篇
  2017年   8篇
  2016年   7篇
  2015年   4篇
  2014年   8篇
  2013年   10篇
  2012年   13篇
  2011年   14篇
  2010年   8篇
  2009年   15篇
  2008年   4篇
  2007年   17篇
  2006年   10篇
  2005年   11篇
  2004年   5篇
  2003年   5篇
  2002年   4篇
  2001年   5篇
  2000年   5篇
  1999年   7篇
  1998年   33篇
  1997年   18篇
  1996年   24篇
  1995年   17篇
  1994年   21篇
  1993年   13篇
  1992年   4篇
  1991年   6篇
  1990年   11篇
  1989年   20篇
  1988年   29篇
  1987年   12篇
  1986年   15篇
  1985年   14篇
  1984年   11篇
  1983年   7篇
  1982年   9篇
  1981年   4篇
  1980年   11篇
  1979年   3篇
  1978年   2篇
  1977年   8篇
  1976年   6篇
  1973年   1篇
  1947年   1篇
排序方式: 共有474条查询结果,搜索用时 15 毫秒
171.
Indium-111 labeled leukocyte imaging was compared with three-phase skeletal scintigraphy as a means of determining whether osteomyelitis was complicating diabetic osteoarthropathy. Three-phase scintigraphy demonstrated increased activity in both infected and noninfected osteopathic bone, with a sensitivity of 75% and a specificity of 56% for osteomyelitis. Leukocyte imaging had the same sensitivity but was most helpful for excluding infection (specificity, 89%) when three-phase imaging could not. Abnormal leukocyte localization was seen at the primary site of infection in all cases within 4 hours after injection. Disadvantages of leukocyte imaging included long preparation time, low count rates resulting in poor spatial resolution, and absence of bone landmarks, which made it difficult to differentiate soft tissue from bone infection.  相似文献   
172.
Jack  CR  Jr; Sharbrough  FW; Marsh  WR 《Radiology》1988,169(2):463-468
The postoperative magnetic resonance imaging studies of 40 patients who underwent surgery for medically refractory temporal lobe epilepsy were reviewed. A method for quantifying the resection of four specific medial temporal lobe structures--amygdala, uncus, hippocampal formation, and parahippocampal gyrus--was used to correlate postoperative seizure control with the degree to which those structures had been resected. Satisfactory postoperative seizure control was found to be strongly dependent (P less than .01) on the performance of at least partial resection of all four medial temporal lobe structures. The total amount of tissue removed did not necessarily correlate with the clinical outcome in individual cases, however, as long as some portion of all four medial structures had been resected. Two complicating factors--the presence of posterior or bilateral independent electroencephalographic foci and a history of meningoencephalitis--each negatively influenced surgical outcome (P less than .01). In cases with a complicating factor and inadequate medial resection, the outcome was invariably poor.  相似文献   
173.
Adaptive histogram equalization, an image-processing technique that distributes pixel values of an image uniformly throughout the gray scale, was applied to 28 plain radiographs of bone lesions, after they had been digitized. The non-equalized and equalized digital images were compared by two skeletal radiologists with respect to lesion margins, internal matrix, soft-tissue mass, cortical breakthrough, and periosteal reaction. Receiver operating characteristic (ROC) curves were constructed on the basis of the responses. Equalized images were superior to nonequalized images in determination of cortical breakthrough and presence or absence of periosteal reaction. ROC analysis showed no significant difference in determination of margins, matrix, or soft-tissue masses.  相似文献   
174.
报道了29个新的1(1取代苯基)2(1H1,2,4三唑或苯并三唑基)O(取代苄基)乙酮肟醚类化合物的合成与体外抗菌试验。结果表明,大多数化合物对大部分真菌有抑菌活性,化合物T1,T4,T6,T11,T12,B1,B3,B4和B6对部分真菌抑菌活性优于或相当于奥昔康唑。  相似文献   
175.
Jack  CR  Jr; Nichols  DA; Sharbrough  FW; Marsh  WR; Petersen  RC 《Radiology》1988,168(3):787-793
Selective testing for memory function with Amytal (amobarbital) in the posterior cerebral artery (PCA) is a promising modification of that test in the internal carotid artery (ICA). This new technique, performed with a Tracker catheter system, was completed successfully in 17 of 20 patients being examined before planned surgery for refractory temporal lobe seizure. The PCA test overcomes three major problems with the ICA technique. First, with the PCA technique, memory testing is begun immediately after injection, when the drug has its peak effect. Second, when the speech-dominant hemisphere is being tested with the PCA test, patients do not become aphasic. Third, injection into the PCA delivers the drug more effectively to the target, the ipsilateral hippocampal formation.  相似文献   
176.
Vertebral bone density in children: effect of puberty   总被引:12,自引:0,他引:12  
To determine changes in bone density during growth, trabecular vertebral density and an index of spinal cortical bone were measured with quantitative computed tomography in 101 children. The children were divided by age into three groups: prepubertal, indeterminate, and pubertal. Compared with prepubertal children, pubertal adolescents had significantly higher trabecular bone density and more compact bone in the spine (P less than .001). After controlling for puberty, vertebral bone density failed to correlate significantly with age, sex, weight, height, surface area, and body mass index. The results indicate that bone density increases markedly during puberty.  相似文献   
177.
报道了29个新的1-(1-取代苯基)-2-(1H-1,2,4-三唑或苯并三唑基)-O-(取代苄基)乙酮肟醚类化合物的合成与体外抗菌试验。结果表明,大多数化合物对大部分真菌有抑菌活性,化合物T1,T4,T6,T11,T12,B1,B3,B4和B6对部分真菌抑菌活性优于或相当于奥昔康唑。  相似文献   
178.
DSA in acute gastrointestinal hemorrhage: clinical and in vitro studies   总被引:3,自引:0,他引:3  
Selective intraarterial digital subtraction angiography (DSA) was used to examine 37 patients with acute gastrointestinal (GI) tract bleeding. Conventional screen-film angiography was used as an adjunct to DSA when a larger field of view was needed (five patients) and when bowel motion prevented the acquisition of adequate image quality with DSA (two patients). Conventional angiography was also performed in all cases in which there were negative DSA examinations. DSA reduced the mean examination time considerably (20% reduction overall), especially for cases involving embolization therapy (35% reduction). DSA was especially valuable in the upper GI tract, where it was used to rapidly locate and/or assist in the embolization of bleeding sites in 19 of 20 patients with positive angiograms. There were 12 true-negative DSA examinations and one false-negative examination due to the limited field of view (9 inches [22.9 cm]). Bowel and respiratory motion were not important problems in the upper GI tract. In the lower GI tract, the usefulness of DSA was severely limited by the small field of view and the misregistration artifact caused by bowel motion. In an in vitro study, DSA and conventional angiography were compared as to their ability to depict several rates of extravasation of contrast material in a model of GI bleeding. DSA tended to be more sensitive for the detection of simulated extravasation (P less than .07).  相似文献   
179.
180.
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