全文获取类型
收费全文 | 259篇 |
免费 | 10篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 14篇 |
妇产科学 | 29篇 |
基础医学 | 27篇 |
口腔科学 | 6篇 |
临床医学 | 26篇 |
内科学 | 33篇 |
皮肤病学 | 6篇 |
神经病学 | 11篇 |
特种医学 | 69篇 |
外科学 | 14篇 |
综合类 | 8篇 |
预防医学 | 7篇 |
药学 | 8篇 |
中国医学 | 2篇 |
肿瘤学 | 8篇 |
出版年
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 11篇 |
2012年 | 10篇 |
2011年 | 7篇 |
2010年 | 15篇 |
2009年 | 16篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 13篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 15篇 |
1997年 | 12篇 |
1996年 | 11篇 |
1995年 | 9篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1939年 | 1篇 |
排序方式: 共有269条查询结果,搜索用时 15 毫秒
11.
12.
Two types of phantoms were developed with which to evaluate the overall performance of digital subtraction angiography (DSA) systems. A dynamic phantom, called a "fish bone" phantom, consists of polyethylene tubes that simulate blood vessels with various lesions, such as stenoses, ulcers, and aneurysms. With this phantom, washout curves were obtained representing the relationship between iodine content and time. It will be useful for qualitative assessment of DSA images, evaluation of different image-processing schemes, and studies of blood flow analysis. A static phantom, called a "C-D" phantom, can be used for measurement of quantitative contrast-detail (C-D) diagrams and for daily monitoring of DSA systems. This was constructed of tubes of seven different diameters (2.15-0.28 mm) and 14 different concentrations of contrast medium (100%-1.1% Renografin-76 [meglumine and sodium diatrizoate]). The C-D diagrams were determined from an observer performance study using C-D phantom images obtained at four different DSA settings. 相似文献
13.
JM Langley JC LeBlanc EE Wang BJ Law NE MacDonald I Mitchell D Stephens J McDonald FD Boucher S Dobson 《Pediatrics》1997,100(6):943-946
OBJECTIVE: To determine nosocomial transmission of respiratory syncytial virus (RSV) in Canadian pediatric hospitals, outcomes associated with nosocomial disease, and infection control practices. DESIGN: A prospective cohort study in the 1992 to 1994 winter respiratory seasons. SETTING: Nine Canadian pediatric university-affiliated hospitals. PARTICIPANTS: Hospitalized children with symptoms of lower respiratory tract infection (at least one of cough, wheezing, dyspnea, tachypnea, and apnea) and RSV antigen identified in a nasopharyngeal aspirate. RESULTS: Of 1516 children, 91 (6%) had nosocomial RSV (NRSV), defined as symptoms of lower respiratory tract infection and RSV antigen beginning >72 hours after admission. The nosocomial ratio (NRSV/[com-munity-acquired RSV {CARSV})] + NRSV) varied by site from 2.8% to 13%. The median length of stay attributable to RSV for community-acquired illness was 5 days, but 10 days for nosocomial illness. Four children with NRSV (4. 4%) died within 2 weeks of infection, compared with 6 (0.42%) with CARSV (relative risk = 10.4, 95% confidence interval: 3.0, 36.4). All sites isolated RSV-positive patients in single rooms or cohorted them. In a multivariate model, no particular isolation policy was associated with decreased nosocomial ratio, but gowning to enter the room was associated with increased risk of RSV transmission (incidence rate ratio 2.81; confidence interval: 1.65, 4.77). CONCLUSIONS: RSV transmission risk in Canadian pediatric hospitals is generally low. Although use of barrier methods varies, all sites cohort or isolate RSV-positive patients in single rooms. Children with risk factors for severe disease who acquire infection nosocomially have prolonged stays and excess mortality. 相似文献
14.
Botsis D Makrakis E Papagianni V Kouskouni E Grigoriou O Dendrinos S Creatsas G 《European journal of obstetrics, gynecology, and reproductive biology》2006,128(1-2):108-112
OBJECTIVE: To assess the value of plasma proMMP-9 levels in predicting the progress of threatened preterm labor to true preterm labor and delivery within 7 days of presentation, along with the ultrasonographic measurement of cervical length. STUDY DESIGN: The study included sixty two pregnant women presented in the 2nd Department of Obstetrics and Gynecology of University of Athens at Aretaieion Hospital with threatened preterm labor. On subjects' presentation, cervical length was evaluated with transvaginal ultrasonography, plasma proMMP-9 levels were measured with the use of a solid phase enzyme immunoassay, and maternal characteristics (smoking, history of preterm delivery and parity) as well as the use of tocolytics were recorded. Subjects were followed up for premature delivery within 7 days. ROC analysis for plasma proMMP-9 levels was performed and logistic regression analysis was used for the evaluation of the prognostic effect of the parameters. RESULTS: The only significant predictors for establishment of true preterm labor and delivery within 7 days of presentation were cervical length (with cutoff value 15 mm: odds ratio=0.022, 95% CI=0.002-0.243, p=0.002) and plasma proMMP-9 (with cutoff value 67.15 ng/ml: odds ratio=0.035, 95% CI=0.003-0.388, p=0.006). The combination of the adopted proMMP-9 and cervical length cutoff values was characterized by a sensitivity of 90.9% and a specificity of 98.3% for predicting the progress to true preterm labor and delivery. CONCLUSION: Plasma proMMP-9 levels could possibly serve as a predictive factor for the progress of threatened preterm labor to true preterm labor and delivery within 7 days of presentation, along with the ultrasonographic evaluation of cervical length. 相似文献
15.
16.
17.
18.
Immunohistochemical study of p185 HER2 and DF3 in primary breast cancer and correlation with CA-15-3 serum tumor marker 总被引:2,自引:0,他引:2
C. Dimas M. Frangos-Plemenos† E. Kouskouni & A. Kondis-Pafitis† 《International journal of gynecological cancer》2002,12(1):74-79
Abstract. Dimas C, Frangos-Plemenos M, Kouskouni E, Kondis-Pafitis A. Immunohistochemical study of p185 HER2 and DF3 in primary breast cancer and correlation with CA-15-3 serum tumor marker.
Human epidermal growth factor receptor 2 (p185 HER2) oncoprotein immunohistochemical expression and DF3 antigen distribution were evaluated in 129 patients with primary breast cancer. p185 HER2 overexpession was positively correlated with the degree of differentiation, metastatic disease, progesterone receptors, and cytoplasmic distribution of DF3 antigen. p185 HER2 overexpression had prognostic significance for the disease-free interval. 相似文献
Human epidermal growth factor receptor 2 (p185 HER2) oncoprotein immunohistochemical expression and DF3 antigen distribution were evaluated in 129 patients with primary breast cancer. p185 HER2 overexpession was positively correlated with the degree of differentiation, metastatic disease, progesterone receptors, and cytoplasmic distribution of DF3 antigen. p185 HER2 overexpression had prognostic significance for the disease-free interval. 相似文献
19.
20.