全文获取类型
收费全文 | 4210篇 |
免费 | 257篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 122篇 |
妇产科学 | 116篇 |
基础医学 | 570篇 |
口腔科学 | 66篇 |
临床医学 | 375篇 |
内科学 | 1011篇 |
皮肤病学 | 115篇 |
神经病学 | 386篇 |
特种医学 | 66篇 |
外科学 | 433篇 |
综合类 | 20篇 |
一般理论 | 3篇 |
预防医学 | 513篇 |
眼科学 | 82篇 |
药学 | 258篇 |
中国医学 | 11篇 |
肿瘤学 | 325篇 |
出版年
2023年 | 29篇 |
2022年 | 61篇 |
2021年 | 128篇 |
2020年 | 76篇 |
2019年 | 129篇 |
2018年 | 140篇 |
2017年 | 81篇 |
2016年 | 73篇 |
2015年 | 101篇 |
2014年 | 150篇 |
2013年 | 239篇 |
2012年 | 324篇 |
2011年 | 339篇 |
2010年 | 229篇 |
2009年 | 154篇 |
2008年 | 320篇 |
2007年 | 299篇 |
2006年 | 286篇 |
2005年 | 261篇 |
2004年 | 228篇 |
2003年 | 225篇 |
2002年 | 205篇 |
2001年 | 27篇 |
2000年 | 14篇 |
1999年 | 28篇 |
1998年 | 32篇 |
1997年 | 31篇 |
1996年 | 23篇 |
1995年 | 23篇 |
1994年 | 19篇 |
1993年 | 24篇 |
1992年 | 16篇 |
1991年 | 21篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1980年 | 13篇 |
1979年 | 5篇 |
1978年 | 11篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 6篇 |
1966年 | 3篇 |
排序方式: 共有4490条查询结果,搜索用时 15 毫秒
61.
Concepción García-Gómez Elvira Esteban Beatriz Sánchez-Pardo María Dolores Fernández 《Ecotoxicology (London, England)》2014,23(7):1195-1209
The interactions and relevance of the soil (total and available) concentrations, accumulation, and acute toxicity of several essential and non-essential trace elements were investigated to determine their importance in environmental soil assessment. Three plant species (T. aestivum, R. sativum, and V. sativa) and E. fetida were simultaneously exposed for 21 days to long-term contaminated soils collected from the surroundings of an abandoned pyrite mine. The soils presented different levels of As and metals, mainly Zn and Cu, and were tested at different soil concentrations [12.5, 25, 50, and 100 % of contaminated soil/soil (w/w)] to increase the range of total and available soil concentrations necessary for the study. The total concentrations in the soils (of both As and metals) were better predictors of earthworm uptake than were the available concentrations. In plants, the accumulation of metals was related to the available concentrations of Zn and Cu, which could indicate that plants and earthworms accumulate elements from different pools of soil contaminants. Moreover, Zn and Cu, which are essential elements, showed controlled uptake at low concentrations. The external metal concentrations predicted earthworm mortality, whereas in plants, the effects on growth were correlated to the As and metal contents in the plants. In general, the bioaccumulation factors were lower at higher exposure levels, which implies the existence of auto-regulation in the uptake of both essential and non-essential elements by plants and earthworms. 相似文献
62.
Cory A. Crane Robert C. Schlauch Samuel W. Hawes Dolores L. Mandel Caroline J. Easton 《Journal of substance abuse treatment》2014
Intimate partner violence (IPV) is a pervasive social concern that may be exacerbated by high rates of alcohol dependence among perpetrators. Society has attempted to combat IPV through various legal interventions, but the effects of specific legal factors on behavioral change and treatment compliance remain largely unexamined. The primary focus of the current study was to comprehensively evaluate the impact of various legal factors (i.e., judicial mandate, judicial monitoring, stage of change, and stake in conformity) on mandatory treatment compliance and behavioral change over a 12 week post-adjudication period among a high-risk sample of alcohol dependent IPV offenders (N = 60). Growth curve analyses revealed effects of judicial monitoring and stage of change such that participants reporting low perceived judicial monitoring and early stages of change reported higher initial levels and a more rapid reduction in IPV than those reporting high perceived judicial monitoring and late stages of change, who reported consistently low IPV. Although we found that legal factors were poor predictors of treatment compliance and alcohol use during treatment, the association between alcohol and IPV was moderated by the legal factors. Stake in conformity was negatively associated with IPV among low alcohol users and positively associated among high alcohol users whereas stage of change was negatively associated with IPV among high alcohol users. The current results suggest that pretreatment legal factors may represent an important consideration in reducing IPV among alcohol dependent offenders. Further research is required to determine the efficacy of legal factors in isolation of treatment as well as methods of manipulating these factors to optimally compliment a prescribed course of treatment. 相似文献
63.
Selene Cansino Frine Torres-Trejo Cinthya Estrada-Manilla Joyce Graciela Martínez-Galindo Evelia Hernández-Ramos Mariana Ayala-Hernández Tania Gómez-Fernández María Dolores Ramírez-González Silvia Ruiz-Velasco 《Age (Dordrecht, Netherlands)》2018,40(3):293-303
Working memory abilities significantly decrease with advancing age; hence, the search for factors that may increase or mitigate this decline is critical. Several factors have been identified that influence working memory; however, their effects have been mainly assessed separately and rarely together with other factors in the same sample. We examined 120 variables to search for factors that jointly act as mediators of working memory decay across the adult life span. A sample of 1652 healthy adults was assessed in spatial and verbal working memory domains. Structural equation modeling analyses were conducted to search for potential mediators that intervened between age and working memory. Only 14 and 10 variables reliably mediated spatial and verbal working memory, respectively. Factors from several domains remained in the models, such as individual characteristics, physiological traits, consumption habits, and regular activities. These factors are sufficiently powerful to influence working memory decline when they jointly interact, as in everyday living. 相似文献
64.
65.
66.
67.
Tracy Anton Mark S. Sklansky Mishella Perez Dolores H. Pretorius 《Journal of ultrasound in medicine》2019,38(12):3335-3347
In 2018, the American Institute of Ultrasound in Medicine revised its obstetric Practice Parameter for the second‐trimester fetal anatomic survey. The 2018 Practice Parameter recommends incorporation of the 3‐vessel view and 3‐vessel and trachea view “if technically feasible.” Sonographers and other medical providers may require additional training and education to develop greater proficiency in obtaining and interpreting these views. This pictorial essay, including ultrasound images alongside their respective schematic diagrams, provides an up‐to‐date, practical, and clinically oriented review of the 3‐vessel view and 3‐vessel and trachea view and their most common presentations in the context of congenital heart disease. 相似文献
68.
69.
70.
Manuel David Gil-Sierra PharmD Silvia Fénix-Caballero PharmD Laila Abdel kader-Martin PharmD Maria Dolores Fraga-Fuentes PharmD Marina Sánchez-Hidalgo PharmD Catalina Alarcón de la Lastra-Romero PharmD Emilio Jesús Alegre-del Rey PharmD 《Journal of clinical pharmacy and therapeutics》2020,45(3):530-538