全文获取类型
收费全文 | 3351篇 |
免费 | 217篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 86篇 |
妇产科学 | 55篇 |
基础医学 | 310篇 |
口腔科学 | 48篇 |
临床医学 | 413篇 |
内科学 | 499篇 |
皮肤病学 | 74篇 |
神经病学 | 133篇 |
特种医学 | 219篇 |
外科学 | 491篇 |
综合类 | 347篇 |
一般理论 | 3篇 |
预防医学 | 333篇 |
眼科学 | 37篇 |
药学 | 298篇 |
3篇 | |
中国医学 | 99篇 |
肿瘤学 | 150篇 |
出版年
2022年 | 27篇 |
2021年 | 55篇 |
2020年 | 53篇 |
2019年 | 40篇 |
2018年 | 33篇 |
2017年 | 62篇 |
2016年 | 51篇 |
2015年 | 63篇 |
2014年 | 79篇 |
2013年 | 108篇 |
2012年 | 152篇 |
2011年 | 130篇 |
2010年 | 117篇 |
2009年 | 131篇 |
2008年 | 162篇 |
2007年 | 169篇 |
2006年 | 150篇 |
2005年 | 133篇 |
2004年 | 87篇 |
2003年 | 67篇 |
2002年 | 82篇 |
2001年 | 81篇 |
2000年 | 85篇 |
1999年 | 72篇 |
1998年 | 49篇 |
1997年 | 56篇 |
1996年 | 61篇 |
1995年 | 52篇 |
1994年 | 49篇 |
1993年 | 44篇 |
1992年 | 47篇 |
1991年 | 42篇 |
1990年 | 41篇 |
1989年 | 31篇 |
1988年 | 46篇 |
1987年 | 47篇 |
1986年 | 28篇 |
1985年 | 53篇 |
1984年 | 38篇 |
1983年 | 28篇 |
1982年 | 19篇 |
1980年 | 18篇 |
1978年 | 22篇 |
1975年 | 25篇 |
1959年 | 41篇 |
1958年 | 66篇 |
1957年 | 76篇 |
1956年 | 73篇 |
1955年 | 83篇 |
1954年 | 51篇 |
排序方式: 共有3619条查询结果,搜索用时 15 毫秒
1.
2.
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
3.
4.
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
5.
6.
7.
8.
M. S. Beer J. A. Stanton Y. Bevan A. Heald A. J. Reeve L. J. Street V. G. Matassa R. J. Hargreaves D. N. Middlemiss 《British journal of pharmacology》1993,110(3):1196-1200
1. The 5-hydroxytryptamine (5-HT) receptor binding selectivity profile of a novel, potent 5-HT1D receptor agonist, L-694,247 (2-[5-[3-(4-methylsulphonylamino)benzyl-1,2,4-oxadiazol-5-yl ]- 1H-indole-3-yl]ethylamine) was assessed and compared with that of the 5-HT1-like receptor agonist, sumatriptan. 2. L-694,247 had an affinity (pIC50) of 10.03 at the 5-HT1D binding site and 9.08 at the 5-HT1B binding site (sumatriptan: pIC50 values 8.22 and 5.94 respectively). L-694,247 retained good selectivity with respect to the 5-HT1A binding site (pIC50 = 8.64), the 5-HT1C binding site (6.42), the 5-HT2 binding site (6.50) and the 5-HT1E binding site (5.66). The pIC50 values for sumatriptan at these radioligand binding sites were 6.14, 5.0, < 5.0 and 5.64 respectively. Both L-694,247 and sumatriptan were essentially inactive at the 5-HT3 recognition site. 3. L-694,247, like sumatriptan, displayed a similar efficacy to 5-HT in inhibiting forskolin-stimulated adenylyl cyclase in guinea-pig substantia nigra although L-694,247 (pEC50 = 9.1) was more potent than sumatriptan (6.2) in this 5-HT1D receptor mediated functional response. L-694,247 (pEC50 = 9.4) was also more potent than sumatriptan (6.5) in a second 5-HT1D receptor mediated functional response, the inhibition of K(+)-evoked [3H]-5-HT release from guinea-pig frontal cortex slices.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
10.
Reeve Bryce B. Hays Ron D. Chang Chih-Hung Perfetto Eleanor M. 《Quality of life research》2007,16(1):1-8
Background Health-related quality of life (HRQL) is an accepted outcome measure in patients with mood and anxiety disorders. Yet, surprisingly
little attention has been paid to the determinants. In this paper we test the hypothesis that it is associated with personality
traits while controlling for mental disorders.
Methods A large sample of outpatients (n=640) with mood and anxiety disorders was studied. The empirically supported five factor model
of normal personality traits was assessed using the NEO-FFI and includes: neuroticism, extraversion, openness to experience,
agreeableness, and conscientiousness. Mental disorders were assessed with the CIDI, and HRQL with the SF-36.
Results Regression analyses revealed that the NEO-FFI scores, with the exception of conscientiousness, were significantly associated
with SF-36 subscales and summary scores, independently from the mental disorders. The percentage of explained variance due
to the personality traits was highest for the subscales Vitality (10.0%), Mental Health (13.3%) and the Mental Health Summary
Score (9.5%). Furthermore, specific personality traits were related to specific SF-36 subscales.
Conclusions A low HRQL of patients with mood or anxiety disorders is not only determined by the disease or the current health but is also
shaped by personality traits that are relatively stable throughout an individual's life time. 相似文献