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   29篇
  国内免费   92篇
耳鼻咽喉   7篇
儿科学   6篇
妇产科学   6篇
基础医学   72篇
口腔科学   10篇
临床医学   78篇
内科学   161篇
皮肤病学   17篇
神经病学   33篇
特种医学   24篇
外科学   47篇
综合类   26篇
预防医学   15篇
眼科学   9篇
药学   80篇
肿瘤学   14篇
  2023年   4篇
  2021年   5篇
  2020年   4篇
  2019年   7篇
  2018年   14篇
  2017年   10篇
  2016年   5篇
  2015年   6篇
  2014年   15篇
  2013年   13篇
  2012年   17篇
  2011年   20篇
  2010年   28篇
  2009年   22篇
  2008年   15篇
  2007年   76篇
  2006年   28篇
  2005年   35篇
  2004年   14篇
  2003年   9篇
  2002年   14篇
  2001年   15篇
  2000年   15篇
  1999年   12篇
  1998年   26篇
  1997年   12篇
  1996年   14篇
  1995年   20篇
  1994年   22篇
  1993年   13篇
  1992年   12篇
  1991年   10篇
  1990年   14篇
  1989年   9篇
  1988年   9篇
  1987年   6篇
  1986年   7篇
  1985年   4篇
  1979年   1篇
  1978年   2篇
  1977年   2篇
  1976年   2篇
  1975年   2篇
  1973年   1篇
  1972年   1篇
  1970年   1篇
  1969年   2篇
  1968年   3篇
  1966年   1篇
  1965年   1篇
排序方式: 共有605条查询结果,搜索用时 0 毫秒
1.
2.
The reluctance of students in health professions to care for AIDS patients is partially based on the perceived risk of transmission of HIV from patient contact. We hypothesize that fear of contagion is due to lack of knowledge and deep‐rooted attitudes and emotions existing even in areas of low HIV seroprevalence. We tested this hypothesis on medical, nursing, and medical technology students. Using a questionnaire that yielded four scales, results showed only 58% of students were knowledgeable, 81% were fearful of contagion, 57% were homophobic, and 8% had death anxiety. Lack of knowledge was correlated with fear of contagion (p < .05), whereas homophobia was weakly associated (p = .08). We conclude that this perceived risk of infection is a result of lack of knowledge, disbelief of the facts, and the interplay of personal values and emotions. Alternative educational methods are needed to increase students’ knowledge and to encourage students to examine their personal feelings and attitudes.  相似文献   
3.
OBJECTIVES: This study was designed to assess the prognostic value of a new variable derived from a cardiopulmonary exercise test, the circulatory power, a surrogate of cardiac power, at peak exercise, in patients with chronic heart failure. BACKGROUND: Peak exercise cardiac power and stroke work are invasive parameters with recently proven prognostic value. It is unclear whether these variables have better prognostic value than peak oxygen uptake (VO(2)). METHODS: The study population comprised 175 patients with chronic heart failure (ejection fraction <45%) who underwent a cardiopulmonary exercise test. Circulatory power and circulatory stroke work were defined as the product of systolic arterial pressure and VO(2) and oxygen pulse, respectively. Prognostic value was assessed by survival curves (Kaplan-Meier method) and uni- and multivariate Cox analyses. RESULTS: With a mean follow-up of 25+/-10 months, ejection fraction, heart rate, systolic arterial pressure, peak VO(2), VCO(2), the anaerobic threshold, minute ventilation, the ventilatory equivalents of oxygen and carbon dioxide, the half times of VO(2) and VCO(2) recoveries, and the circulatory stroke work and power predicted outcome. Multivariate analysis demonstrated that the peak circulatory power (chi-square=19.9, P<0.001) (but not peak circulatory stroke work) was the only variable predictive of prognosis. CONCLUSION: The prognostic value of cardiopulmonary exercise tests in heart failure patients can be improved by assessing a new variable, the circulatory power - a surrogate of cardiac power - at peak exercise.  相似文献   
4.
5.
A phase III prospective randomized multicenter study was performed to determine whether quinine could improve the response rate of poor-risk acute leukemias (ALs) to standard chemotherapy including a multidrug resistance (MDR)-related cytotoxic agent. The rationale of the study was based on the negative prognostic value of MDR phenotype in ALs and the ability of quinine to reverse this phenotype both in vitro and ex vivo. Three hundred fifteen patients (median age, 49 years; range, 16 to 65) with relapsed (n = 108) or refractory (n = 32) acute myeloblastic leukemia (AML), relapsed (n = 27) or refractory (n = 9) acute lymphoblastic leukemia (ALL), secondary AL (n = 22) or blastic transformation of myelodysplastic syndrome ([MDS] n = 74) or myeloproliferative syndrome ([MPS] n = 43) were randomly assigned to receive mitoxantrone ([MXN] 12 mg/m2/d, days 2 to 5) and cytarabine ([Ara-C] 1 g/m2/12 h, days 1 to 5) alone or in combination with quinine (30 mg/kg/d, days 1 to 5; continuous intravenous infusion beginning 24 hours before MXN infusion). Side effects of quinine were observed in 56 of 161 quinine-treated patients and disappeared in all but four cases after one or two 20% dose decreases. Sera from quinine-treated patients showed increased MXN uptake in an MDR-positive cell line compared with matched sera obtained before quinine infusion. Quinine induced a significant increase in the incidence of nausea, vomiting, mucositis, and cardiac toxicity. A complete response (CR) was observed in 85 of 161 patients (52.8%) from the quinine-treated group versus 70 of 154 patients (45.5%) in the control group (P = .19). The most important differences between quinine and control group CR rates were observed in patients with refractory AMLs and blastic transformation of MDS and MPS. The CR rate was higher in P-glycoprotein-positive cases, although the difference was not significant. Failure of the regimen due to blastic persistence or blast number increase was higher in the control group (61 of 154 patients) than in the quinine group (45 of 161, P = .04). Early death was observed in eight cases (four in each arm) and death in aplasia in 27 cases (20 in quinine group v seven in control group, P = .01). The significant increase of toxicity in the quinine arm could have masked the clinical benefit of MDR reversion in poor- risk ALs.  相似文献   
6.
7.
8.
9.
10.
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