全文获取类型
收费全文 | 365990篇 |
免费 | 9863篇 |
国内免费 | 573篇 |
专业分类
耳鼻咽喉 | 3857篇 |
儿科学 | 12603篇 |
妇产科学 | 7920篇 |
基础医学 | 42512篇 |
口腔科学 | 8067篇 |
临床医学 | 25132篇 |
内科学 | 75221篇 |
皮肤病学 | 6754篇 |
神经病学 | 32000篇 |
特种医学 | 13206篇 |
外国民族医学 | 31篇 |
外科学 | 53716篇 |
综合类 | 3284篇 |
一般理论 | 50篇 |
预防医学 | 36702篇 |
眼科学 | 6659篇 |
药学 | 22689篇 |
中国医学 | 1258篇 |
肿瘤学 | 24765篇 |
出版年
2023年 | 1090篇 |
2022年 | 1997篇 |
2021年 | 4660篇 |
2020年 | 2460篇 |
2019年 | 4389篇 |
2018年 | 27075篇 |
2017年 | 20474篇 |
2016年 | 22757篇 |
2015年 | 5098篇 |
2014年 | 6478篇 |
2013年 | 8857篇 |
2012年 | 19069篇 |
2011年 | 33152篇 |
2010年 | 25397篇 |
2009年 | 17283篇 |
2008年 | 29349篇 |
2007年 | 31984篇 |
2006年 | 11162篇 |
2005年 | 12691篇 |
2004年 | 13007篇 |
2003年 | 13197篇 |
2002年 | 10910篇 |
2001年 | 5650篇 |
2000年 | 5907篇 |
1999年 | 4846篇 |
1998年 | 1677篇 |
1997年 | 1270篇 |
1996年 | 1091篇 |
1995年 | 987篇 |
1994年 | 828篇 |
1993年 | 700篇 |
1992年 | 2365篇 |
1991年 | 2294篇 |
1990年 | 2155篇 |
1989年 | 1856篇 |
1988年 | 1692篇 |
1987年 | 1643篇 |
1986年 | 1519篇 |
1985年 | 1468篇 |
1984年 | 1099篇 |
1983年 | 956篇 |
1979年 | 1032篇 |
1978年 | 707篇 |
1975年 | 699篇 |
1974年 | 918篇 |
1973年 | 872篇 |
1972年 | 757篇 |
1971年 | 701篇 |
1970年 | 774篇 |
1969年 | 734篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
33.
34.
35.
Ángela M. Ortega-Galán M. Dolores Ruiz-Fernández Rocío Ortiz-Amo José Cabrera-Troya Inés M. Carmona-Rega Olivia Ibáñez-Masero 《Enfermería clínica》2019,29(1):10-17
Objective
To discover the experiences of end-of-life patients attended by the emergency services, through the discourse of the family caregivers who accompanied the family member in this care transit.Method
A qualitative approach study, based on the paradigm of hermeneutical phenomenology. In total, 81 family caregivers participated. The techniques used were the in-depth interview and the discussion group, with a total of 5 discussion groups and 41 interviews. The period of data collection was carried out between January 2013 and June 2014.Results
In the network of discourses obtained with respect to “Urgent Care”, all the codes were grouped in relation to a single argumentative line: deficiencies in urgent care. Among them, we found different dimensions that are established depending on the different times of care, or the different determinant aspects of these deficiencies: disorganization of the care received, lack of experience of the professionals in emergencies, application of general protocols in the emergency services, inadequate care in the treatment received, delays in emergency care.Conclusions
In general, we highlight the dissatisfaction of the family members with respect to the care received from the emergency services. The needs of these types of situation are not covered from these services and are of low quality. Therefore, it is necessary to reorient the care protocols for these patients. 相似文献36.
José A. Lorente Pablo Cardinal-Fernández Diego Muñoz Fernando Frutos-Vivar Arnaud W. Thille Carlos Jaramillo Aida Ballén-Barragán José M. Rodríguez Oscar Peñuelas Guillermo Ortiz José Blanco Bruno Valle Pinheiro Nicolás Nin María del Carmen Marin Andrés Esteban Taylor B. Thompson 《Intensive care medicine》2015,41(11):1921-1930
37.
38.
Konrad Matyja Anna Małachowska-Jutsz Anna K. Mazur Kazimierz Grabas 《Ecotoxicology (London, England)》2016,25(5):924-939
Dehydrogenase activity is frequently used to assess the general condition of microorganisms in soil and activated sludge. Many studies have investigated the inhibition of dehydrogenase activity by various compounds, including heavy metal ions. However, the time after which the measurements are carried out is often chosen arbitrarily. Thus, it can be difficult to estimate how the toxic effects of compounds vary during the reaction and when the maximum of the effect would be reached. Hence, the aim of this study was to create simple and useful mathematical model describing changes in dehydrogenase activity during exposure to substances that inactivate enzymes. Our model is based on the Lagergrens pseudo-first-order equation, the rate of chemical reactions, enzyme activity, and inactivation and was created to describe short-term changes in dehydrogenase activity. The main assumption of our model is that toxic substances cause irreversible inactivation of enzyme units. The model is able to predict the maximum direct toxic effect (MDTE) and the time to reach this maximum (TMDTE). In order to validate our model, we present two examples: inactivation of dehydrogenase in microorganisms in soil and activated sludge. The model was applied successfully for cadmium and copper ions. Our results indicate that the predicted MDTE and TMDTE are more appropriate than EC50 and IC50 for toxicity assessments, except for long exposure times. 相似文献
39.
40.
Contraceptive use is an important strategy for the prevention of unwanted pregnancy and avoidance of induced abortion. Of all the contraception methods, emergency contraceptive (EC) offers the last chance to achieve this. However, few studies have documented the use of EC among young people in Ghana. This study explored knowledge and usage of EC as well as the factors associated with it among University of Cape Coast students. Data were obtained on the knowledge and usage of ECs among University of Cape Coast students in 2013. Logistic regression analysis was used to investigate the association between students’ socio-demographic characteristics and EC knowledge and use. More male students (72 %) than females (59 %) were sexually active. Fifty-seven percent of the respondents had ever heard of EC and 36 % had ever used EC. Although males were more likely to be sexually active, females were more likely to have knowledge of EC use compared to males. The study underscores the need to increase awareness regarding EC among University students in order to offer them the opportunity that EC provides if other forms of contraceptives are missed. 相似文献