全文获取类型
收费全文 | 1749203篇 |
免费 | 121000篇 |
国内免费 | 4724篇 |
专业分类
耳鼻咽喉 | 22381篇 |
儿科学 | 57053篇 |
妇产科学 | 46437篇 |
基础医学 | 268420篇 |
口腔科学 | 46078篇 |
临床医学 | 167276篇 |
内科学 | 330968篇 |
皮肤病学 | 35857篇 |
神经病学 | 138279篇 |
特种医学 | 63940篇 |
外国民族医学 | 418篇 |
外科学 | 246385篇 |
综合类 | 35413篇 |
现状与发展 | 3篇 |
一般理论 | 551篇 |
预防医学 | 144803篇 |
眼科学 | 38880篇 |
药学 | 130448篇 |
7篇 | |
中国医学 | 4067篇 |
肿瘤学 | 97263篇 |
出版年
2021年 | 13935篇 |
2019年 | 14551篇 |
2018年 | 20500篇 |
2017年 | 15316篇 |
2016年 | 16925篇 |
2015年 | 19232篇 |
2014年 | 26302篇 |
2013年 | 40258篇 |
2012年 | 56205篇 |
2011年 | 60237篇 |
2010年 | 34934篇 |
2009年 | 31814篇 |
2008年 | 54958篇 |
2007年 | 58747篇 |
2006年 | 58407篇 |
2005年 | 56202篇 |
2004年 | 53990篇 |
2003年 | 51464篇 |
2002年 | 49851篇 |
2001年 | 77196篇 |
2000年 | 79219篇 |
1999年 | 66245篇 |
1998年 | 18680篇 |
1997年 | 16628篇 |
1996年 | 16474篇 |
1995年 | 15655篇 |
1994年 | 14484篇 |
1992年 | 52447篇 |
1991年 | 52658篇 |
1990年 | 51493篇 |
1989年 | 49275篇 |
1988年 | 45483篇 |
1987年 | 44640篇 |
1986年 | 42318篇 |
1985年 | 40429篇 |
1984年 | 30346篇 |
1983年 | 25842篇 |
1982年 | 15018篇 |
1979年 | 27909篇 |
1978年 | 19872篇 |
1977年 | 16168篇 |
1976年 | 16241篇 |
1975年 | 17466篇 |
1974年 | 20895篇 |
1973年 | 20241篇 |
1972年 | 18743篇 |
1971年 | 17677篇 |
1970年 | 16379篇 |
1969年 | 14965篇 |
1968年 | 14269篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
996.
Andrew F Shorr William L Jackson Brendan M Weiss Lisa K Moores 《Blood coagulation & fibrinolysis》2007,18(4):309-316
Multiple options exist for the prevention of deep vein thrombosis (DVT) in medical inpatients. We sought to determine the cost-effectiveness of low-molecular-weight heparin (LMWH) relative to unfractionated heparin (UFH) for DVT prevention in this setting. We conducted a cost-effectiveness analysis from the perspective of a third-party payer employing a decision model and literature-based estimates for inputs. In the base-case analysis, LMWH had little impact on the rate of DVT. Despite higher acquisition costs, however, LMWHs resulted in net savings. Routine use of LMWH saves approximately US$89 per patient. The lower rate of heparin-induced thrombocytopenia (HIT) with LMWH accounted for this differential. Univariate sensitivity analysis revealed the model was moderately sensitive to the odds ratio of HIT with LMWH and the cost of HIT. Multivariate sensitivity analysis confirmed the LMWH approach dominated financially. 'Worst-case' scenario modeling, where LMWH actually increased the risk for DVT, had little effect on the rate of HIT, and was substantially more costly than UFH, still demonstrated that LMWHs were economically superior. Monte-Carlo simulation indicated the 95% confidence interval around the estimate for savings with LMWH ranged from US$7 to US$373. We conclude that, despite their higher cost, LMWHs for thromboprophylaxis in medical patients result in savings. 相似文献
997.
Endotracheal intubation is required in 5–10% of all prehospital emergencies. Poor environmental conditions (e.g. limited space, poor or excessive lighting etc.), unfavorable patient-related factors (e.g. trauma, bleeding, pulmonary aspiration etc.) and the pressure of time make prehospital airway management a challenging procedure even for experienced emergency physicians. The incidence of difficult endotracheal intubation is significantly higher than in-hospital. Profound clinical practice, recognition and adequate treatment of complications of intubation, and ongoing clinical practice are essential for successful and responsible prehospital airway management. A brief physical examination helps to identify predictors for difficult intubation, thereby modifying treatment strategies. Every emergency physician must be closely familiar with at least one supraglottic airway device and the recent algorithms to manage the unanticipated difficult airway. 相似文献
998.
999.
1000.
C Cote M D Zilberberg S H Mody L J Dordelly B Celli 《The European respiratory journal》2007,29(5):923-929
Haemoglobin (Hb) abnormalities in chronic obstructive pulmonary disease (COPD) are not well characterised. The present authors investigated the prevalence and association of abnormal Hb with clinical outcomes. Analysis of a prospective cohort of stable COPD outpatients (n = 683) in a USA Veterans Administration pulmonary clinic was undertaken. Patients were classified as anaemic (Hb <13 g.dL(-1)), polycythemic (Hb > or =17 g.dL(-1) and > or =15 g.dL(-1) for males and females, respectively) or normal. Demographic characteristics and physiological/functional outcomes were compared between groups. Regression models adjusting for confounders examined the independent association of anaemia with clinical outcomes. Anaemia was present in 116 (17%) patients and polycythemia in 40 (6%). While the only values that differed between polycythemic and nonpolycythemic patients were mean body mass index and Hb, anaemic patients showed a significantly higher modified Medical Research Council dyspnoea scale score (2.8 versus 2.6), lower 6-min walk distance (265 versus 325 m) and shorter median survival (49 versus 74 months) than nonanaemic patients. In regression models, anaemia independently predicted dyspnoea and reduced exercise capacity. Anaemia in chronic obstructive pulmonary disease was an independent risk factor for reduced functional capacity. Polycythemia prevalence was low and had no association with worsened outcomes. Further work is required to evaluate the effect of anaemia correction on outcomes in chronic obstructive pulmonary disease. 相似文献