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   484篇
  免费   56篇
  国内免费   5篇
耳鼻咽喉   9篇
儿科学   48篇
妇产科学   10篇
基础医学   58篇
口腔科学   27篇
临床医学   51篇
内科学   106篇
皮肤病学   20篇
神经病学   20篇
特种医学   78篇
外科学   35篇
综合类   17篇
预防医学   8篇
药学   30篇
肿瘤学   28篇
  2023年   1篇
  2022年   4篇
  2021年   2篇
  2020年   4篇
  2019年   7篇
  2018年   7篇
  2017年   6篇
  2016年   7篇
  2015年   12篇
  2014年   20篇
  2013年   21篇
  2012年   10篇
  2011年   12篇
  2010年   40篇
  2009年   28篇
  2008年   15篇
  2007年   12篇
  2006年   13篇
  2005年   14篇
  2004年   9篇
  2003年   11篇
  2002年   5篇
  2001年   4篇
  2000年   3篇
  1999年   8篇
  1998年   29篇
  1997年   34篇
  1996年   33篇
  1995年   27篇
  1994年   18篇
  1993年   17篇
  1992年   4篇
  1991年   1篇
  1990年   2篇
  1989年   13篇
  1988年   13篇
  1987年   17篇
  1986年   10篇
  1985年   8篇
  1984年   4篇
  1983年   3篇
  1982年   6篇
  1981年   10篇
  1980年   4篇
  1979年   3篇
  1978年   2篇
  1977年   5篇
  1976年   6篇
  1954年   1篇
排序方式: 共有545条查询结果,搜索用时 15 毫秒
31.
32.
Rotator cuff tear: clinical experience with sonographic detection   总被引:5,自引:0,他引:5  
Soble  MG; Kaye  AD; Guay  RC 《Radiology》1989,173(2):319-321
Between June 1986 and April 1988, 86 sonographic examinations of the shoulder were performed on patients suspected of having rotator cuff tears. Major sonographic diagnostic criteria included (a) a well-defined discontinuity usually visible as a hypoechoic focus within the cuff, (b) nonvisualization of the cuff and (c) an echogenic focus within the cuff. Seventy-five patients underwent both sonography and arthrography. Compared with arthrography alone, ultrasound examinations enabled detection of 92% of rotator cuff tears (24 of 26 tears), with a specificity of 84% and a negative predictive value of 95%. Correlation was obtained in 30 of these patients who underwent surgery for rotator cuff tear or other soft-tissue abnormality. In this group, the sensitivity of sonography for detection of a tear was 93%, with a specificity of 73%, while for arthrography sensitivity was 87% and specificity was 100%. These data indicate that sonography is a useful, noninvasive screening procedure for patients suspected of having rotator cuff injury.  相似文献   
33.
Computed tomography of the pancreas   总被引:2,自引:0,他引:2  
  相似文献   
34.

Background  

Chronic lymphocytic leukemia (CLL) is a monoclonal disorder, characterized by a progressive proliferation of functionally incompetent B lymphocytes. There is increased evidence of association between CLL and skin cancers, including the uncommon Merkel cell carcinoma (MCC).  相似文献   
35.
Some studies report an increased risk of autoimmune thyroid disease in hepatitis C and B as well as in interferon therapy. Recently a new link between HCV and papillary thyroid cancer has been published. The mechanism responsible for the oncogenetic role of HCV is not well understood, but it involves immunity system and autoimmunity disorders. We designed a case-control study on HCV exposure. To assess the positivity to HCV ELISA test and polymerize chain reaction technique (PCR) were used. For statistical analysis an odds ratio and corresponding 95% confidence intervals were computed using unconditional multiple-logistic-regression models. Our findings show a statistically significant association between HCV and papillary thyroid cancer (OR = 3.3, 95% CI 1.5-7.4, p=0.003), overall in female gender (OR = 3.3, 95% CI 1.2-8.7, p=0.01) and in the > or =50 years age category the risk for thyroid cancer was confirmed by the OR = 3.2 (95% CI 1.3-7.9, p=0.01). Based on our study there is an association between HCV and thyroid cancer and it is more readily detectable in countries with a high prevalence of HCV.  相似文献   
36.
Securinega virosa is used traditionally as sedative in children and in mental illnesses. In this study, the behavioral effects of methanolic root bark extract of S. virosa were investigated in mice. The results revealed that the extract significantly (P<0.05) and dose-dependently reduced the onset and prolonged the duration of sleep. The extract significantly (P<0.05) decreased exploratory activity and reduced the rate of apomorphine-induced stereotyped climbing at the doses tested (6.25–25mg/kg). It also produced a significant and dose-dependent motor coordination deficit in mice at the doses tested (P<0.01). The intraperitoneal median lethal dose in mice was 774.6mg/kg while the preliminary phytochemical screening revealed the presence of alkaloids, tannins, saponins and flavonoids. These results suggest that methanolic root bark extract of S. virosa contains biologically active principles that are sedative in nature and lend pharmacological credence to the ethnomedical use of the plant.  相似文献   
37.
Pulmonary lymphangitic spread of carcinoma: appearance on CT scans   总被引:6,自引:0,他引:6  
Stein  MG; Mayo  J; Muller  N; Aberle  DR; Webb  WR; Gamsu  G 《Radiology》1987,162(2):371-375
Chest computed tomography (CT), including high-resolution CT with thin (1.5-mm) sections was used to evaluate proved (pathologically or clinically) lymphangitic spread (LS) of tumor in 12 patients. These appearances were compared with thin-section scans obtained in 11 healthy subjects. Thin-section CT demonstrated findings consistent with thickening of the normal lung interstitium. In all patients, thin sections showed an increase in the number of peripheral lines (1-2 cm in length) that were diffuse in generalized disease and localized in focal disease. Normal peripheral arcades were not increased in number, but the limbs forming the arcades were thickened in all patients. A diffuse increase in linear and curvilinear structures (reticular pattern) was seen toward the center of the lung. Polygonal structures 1-2 cm in diameter were seen in seven patients with LS but not in healthy subjects. Fissures were thickened in nine patients. Selected 1.5-mm-thick CT sections are recommended through abnormal areas (seen at CT or on chest radiographs) or if these are normal at three levels (midapex, hilus, and 3 cm above the diaphragm) when scanning patients with tumors known to cause LS.  相似文献   
38.
Eight patients (seven post partum, one post abortion) with massive pelvic hemorrhage related to pregnancy and one patient with uncontrollable bleeding following a cervical biopsy underwent angiography to facilitate the identification and treatment of bleeding sites. In all nine patients pelvic hemorrhage was successfully controlled with embolization under angiographic guidance. Angiographic embolization allowed preservation of the uterus in six patients referred prior to hysterectomy, and one patient subsequently became pregnant. When conservative measures and minor surgical repairs have failed, embolization should be the next step in the treatment of postpartum hemorrhage to avoid major surgery in an unstable patient and to maintain reproductive function.  相似文献   
39.
Several studies have shown the benefit of withdrawal therapy when medication overuse headache (MOH) is suspected. Our aim was to compare the effect of withdrawal therapy in patients followed by a neurologist (group A, n  = 42) and a primary care physician (PCP) (group B, n  = 38). Patients were randomized to A or B, and follow-up was at 3, 6 and 12 months. Calculated mean headache (MH at 6 months + MH at 12 months)/2 (primary end-point) was similar; A 1.04 (0.87, 1.21) and B 1.02 (0.82, 1.21) ( P  = 0.87). The number of patients with 50% improvement of headache days was also similar; 14/42 in group A vs. 12/34 in B ( P  = 0.86) at 3 months, 15/42 vs. 11/33 ( P  = 0.83) at 6 months and 15/42 vs. 14/38 ( P  = 0.92) at 12 months. Days without headache during the last 9 months of follow-up were 123 (96, 150) in group A and 137 (112, 161) in B ( P  = 0.62). After 3 months one-third were classified as MOH. Patients with MOH improved similarly in group A and B, and so did patients without MOH. Within 1 year 7/42 in A and 9/38 in B had recurrent medication overuse ( P  = 0.43). In summary, there were no significant differences in follow-up results between the two groups.  相似文献   
40.
Treatment of uroepithelial cells with lipoteichoic acid from Staphylococcus saprophyticus resulted in a decrease in the adherence of this organism. Similar effects were observed when bacteria were pretreated with the lipoteichoic acid ligands albumin and anti-polyglycerophosphate monoclonal antibodies. Lipoteichoic acid might behave as an adhesin of S. saprophyticus.  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