全文获取类型
收费全文 | 2724篇 |
免费 | 122篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 39篇 |
儿科学 | 74篇 |
妇产科学 | 196篇 |
基础医学 | 234篇 |
口腔科学 | 29篇 |
临床医学 | 336篇 |
内科学 | 388篇 |
皮肤病学 | 46篇 |
神经病学 | 108篇 |
特种医学 | 209篇 |
外科学 | 232篇 |
综合类 | 324篇 |
一般理论 | 1篇 |
预防医学 | 256篇 |
眼科学 | 33篇 |
药学 | 225篇 |
3篇 | |
中国医学 | 99篇 |
肿瘤学 | 65篇 |
出版年
2023年 | 15篇 |
2022年 | 26篇 |
2021年 | 42篇 |
2020年 | 48篇 |
2019年 | 32篇 |
2018年 | 15篇 |
2017年 | 34篇 |
2016年 | 33篇 |
2015年 | 47篇 |
2014年 | 60篇 |
2013年 | 82篇 |
2012年 | 144篇 |
2011年 | 135篇 |
2010年 | 112篇 |
2009年 | 107篇 |
2008年 | 148篇 |
2007年 | 145篇 |
2006年 | 134篇 |
2005年 | 118篇 |
2004年 | 70篇 |
2003年 | 51篇 |
2002年 | 50篇 |
2001年 | 69篇 |
2000年 | 49篇 |
1999年 | 56篇 |
1998年 | 43篇 |
1997年 | 46篇 |
1996年 | 56篇 |
1995年 | 44篇 |
1994年 | 47篇 |
1993年 | 35篇 |
1992年 | 22篇 |
1991年 | 32篇 |
1990年 | 36篇 |
1989年 | 32篇 |
1988年 | 31篇 |
1987年 | 30篇 |
1986年 | 16篇 |
1985年 | 30篇 |
1984年 | 24篇 |
1983年 | 12篇 |
1980年 | 13篇 |
1977年 | 12篇 |
1959年 | 44篇 |
1958年 | 66篇 |
1957年 | 75篇 |
1956年 | 73篇 |
1955年 | 83篇 |
1954年 | 51篇 |
1948年 | 12篇 |
排序方式: 共有2897条查询结果,搜索用时 31 毫秒
1.
乐敏飞 《中国公共卫生管理》2016,(4):477-479
目的调查宁波市北仑区0~14岁儿童哮喘发病率、发病规律及危险因素,为制定防治措施提供参考。方法2013年1月-2014年1月,采用整群抽样法抽取北仑区19所学校0~14岁儿童为调查对象进行问卷调查,对筛查出的疑似哮喘儿童进行确诊,并对其人口学特征进行分析,采用logistic回归方程分析危险因素。结果调查收回有效问卷23 781份,共检出哮喘患儿534例,发病率为2.25%,男女发病率比例为1.92:1。其中发病较轻患儿占44.01%,中度占31.46%,重度占24.53%。发病时间以换季、冬季为主,分别占35.96%、32.02%。多因素logistic回归分析显示,呼吸道感染、药物过敏史、家族过敏史和食物过敏史是儿童哮喘发病的危险因素(P<0.05)。结论北仑区儿童哮喘发病率较高,具有性别和季节发病差异,应加大对患病危险因素的宣传,规范标准化治疗方案,减少儿童哮喘疾病的发生。 相似文献
2.
Reactive oxygen species and human spermatozoa: physiology and pathology 总被引:20,自引:1,他引:19
The role of reactive oxygen species (ROS) in the pathophysiology of human sperm function has been emphasized in recent years. ROS production in semen has been associated with loss of sperm motility, decreased capacity for sperm–oocyte fusion and loss of fertility. There is a current presumption that the most prolific source of ROS in sperm suspensions is an NADPH oxidase located in leukocytes or in spermatozoa which produces superoxide which is further converted to peroxide by the action of superoxide dismutase. Hydrogen peroxide has been recognized as the most toxic oxidizing species for human spermatozoa, which are very sensitive to lipid peroxidation owing to the high content of polyunsaturated fatty acids in their plasma membrane, though this is not the sole mechanism by which sperm function might be impaired by ROS. Although the excessive production of ROS is detrimental to human spermatozoa, there is a growing body of evidence which suggests that ROS are also involved in the physiological control of some sperm functions. This review focuses on the nature and source of the ROS generated by human spermataozoa as well as their operational mechanisms and their effects, which may be detrimental or beneficial. 相似文献
3.
4.
5.
6.
研究不同微生物诱导家蝇幼虫表达的抗菌肽特性.用3种不同的病源菌通过针刺感染的方法诱导家蝇幼虫表达抗菌肽,通过Sephadex G25分离,用Hult mark改进法和抑菌圈测定法作抑菌试验,用毛细管电泳(CE)分析不同微生物诱导得到的抗菌肽样品差异,检测抗菌肽的热稳定性和酸碱耐受性.发现不同微生物诱导产生的家蝇抗菌肽具有广谱抑菌性,但不同样品对不同病源菌抑菌活性有差异,不同测定抑菌效果的方法对抑菌结果有影响,各种抗菌肽样品CE蛋白谱具有明显不同.抗菌肽样品都具有热稳定性和酸碱耐受性.说明不同微生物诱导产生的家蝇抗菌肽类型以及抗菌肽含量与诱导源有关,抗菌肽为家蝇幼虫体内固有成分,诱导增加了抗菌肽的表达量同时刺激新抗菌肽的产生.用志贺氏菌、金黄色葡萄球菌、鼠伤寒沙门氏菌诱导家蝇幼虫可产生较多含量高活性好的抗菌肽. 相似文献
7.
8.
胃癌组织中核基质蛋白的变化 总被引:1,自引:1,他引:0
目的:研究胃癌组织核基质蛋白的改变。方法:应用SDS-PAGE技术及Geneools定量分析软件,对22例胃癌组织及正常组织的核心基质蛋白进行了研究,结果:胃癌组织与正常组织比较,Mr为30000,28000的核基质蛋白表达量明显减少(P<0.05),不同分化类型及不同临床分期胃癌组织间比较,此种核基质蛋白表达量差异无统计学意义(P>0.05),结论:胃癌组织中核基质蛋白的改变可能在肿瘤的早期已经发生,是胃癌发生的早期分子事件。 相似文献
9.
Prevalence, morbidity and service need among South Asian and white adults with intellectual disability in Leicestershire, UK 总被引:1,自引:0,他引:1
C. W. McGrother S. Bhaumik C. F. Thorp J. M. Watson & N. A. Taub 《Journal of intellectual disability research : JIDR》2002,46(4):299-309
Background Previous reports have suggested that South Asian and white UK populations have different prevalences of intellectual disability (ID), related psychological morbidity and service use. The aim of the present study was to compare these rates among South Asian and white adults in Leicestershire, UK. Method This cross‐sectional study is comprised of two parts. The analysis of prevalence is based on data from all South Asian and white adults known to the Leicestershire Learning Disabilities Register in 1991, with population denominators being drawn from the 1991 census. The other analyses use data collected from the most recent semi‐structured home interviews, carried out between 1987 and 1998, with 206 South Asian and 2334 white adults. Results The prevalence of ID in adults in Leicestershire is 3.20 per 1000 in South Asians and 3.62 per 1000 in whites. Among adults with ID, South Asians have similar prevalences of disabilities to whites and significantly lower skill levels. South Asians show similar levels of psychological morbidity, but make significantly lower use than whites of psychiatric services, residential care and respite care. South Asians use community services as extensively as whites, but feel that they have a substantially greater unmet need, especially with regard to social services. Conclusion South Asian and white populations have similar prevalences of ID and related psychological morbidity. Culturally appropriate services for South Asian adults may need to focus on skill development and community care. 相似文献
10.
Physical aggression towards others in adults with learning disabilities: prevalence and associated factors 总被引:1,自引:0,他引:1
F. Tyrer C. W. McGrother C. F. Thorp M. Donaldson S. Bhaumik J. M. Watson & C. Hollin 《Journal of intellectual disability research : JIDR》2006,50(4):295-304
Background Many people with learning disabilities (LD) show aggressive behaviour, but the extent of the problem and its associated factors and effects are unclear. Methods A cross‐sectional analysis was carried out using interview data from 3065 adults with LD on the Leicestershire LD Register. Physical aggression towards others was defined as carers reporting frequent (more than three times per week) and/or severe episodes. Individuals with and without aggression were compared using multiple logistic regression models for potential physical and psychological factors. Results Carers reported that 443 (14%) of adults were physically aggressive towards others. Men (P = 0.001), younger individuals (P < 0.001), people with more severe LD (P < 0.001) and those in institutional settings (P < 0.001) had a significantly higher prevalence of physical aggression. People with Down syndrome had a lower prevalence of physical aggression (P < 0.001). After adjustment, we found no relationship between aggression and the presence of epilepsy or autism. Among psychological factors, symptoms of frustration (P < 0.001) and mood swings (P < 0.001) were associated with higher levels of aggression. Failure to cope among carers was reported by 14% overall: 42% of people caring for adults with aggression said they were unable to cope compared with 10% of those caring for adults without aggression. Conclusions Physical aggression towards other people presents a significant challenge to carers of adults with LD. Further research is needed to identify aetiological factors with a view to finding effective interventions to reduce, and improve management of, this behaviour. 相似文献