全文获取类型
收费全文 | 4295篇 |
免费 | 197篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 106篇 |
儿科学 | 85篇 |
妇产科学 | 58篇 |
基础医学 | 435篇 |
口腔科学 | 101篇 |
临床医学 | 414篇 |
内科学 | 943篇 |
皮肤病学 | 62篇 |
神经病学 | 401篇 |
特种医学 | 229篇 |
外科学 | 483篇 |
综合类 | 315篇 |
预防医学 | 305篇 |
眼科学 | 39篇 |
药学 | 342篇 |
3篇 | |
中国医学 | 104篇 |
肿瘤学 | 134篇 |
出版年
2023年 | 22篇 |
2022年 | 47篇 |
2021年 | 72篇 |
2020年 | 52篇 |
2019年 | 52篇 |
2018年 | 67篇 |
2017年 | 69篇 |
2016年 | 55篇 |
2015年 | 70篇 |
2014年 | 97篇 |
2013年 | 150篇 |
2012年 | 251篇 |
2011年 | 228篇 |
2010年 | 174篇 |
2009年 | 170篇 |
2008年 | 239篇 |
2007年 | 226篇 |
2006年 | 224篇 |
2005年 | 197篇 |
2004年 | 142篇 |
2003年 | 131篇 |
2002年 | 119篇 |
2001年 | 135篇 |
2000年 | 122篇 |
1999年 | 110篇 |
1998年 | 50篇 |
1997年 | 58篇 |
1996年 | 64篇 |
1995年 | 54篇 |
1994年 | 52篇 |
1993年 | 41篇 |
1992年 | 39篇 |
1991年 | 49篇 |
1990年 | 41篇 |
1989年 | 44篇 |
1988年 | 56篇 |
1987年 | 48篇 |
1986年 | 31篇 |
1985年 | 48篇 |
1984年 | 36篇 |
1983年 | 31篇 |
1980年 | 17篇 |
1979年 | 17篇 |
1975年 | 16篇 |
1959年 | 41篇 |
1958年 | 66篇 |
1957年 | 75篇 |
1956年 | 73篇 |
1955年 | 83篇 |
1954年 | 51篇 |
排序方式: 共有4559条查询结果,搜索用时 15 毫秒
1.
Deitelzweig Steve Luo Xuemei Nguyen Jennifer L. Malhotra Deepa Emir Birol Russ Cristina Li Xiaoyan Lee Theodore C. Ferri Mauricio Wiederkehr Danny Reimbaeva Maya Barnes Geoffrey D. Piazza Gregory 《Journal of thrombosis and thrombolysis》2022,54(4):696-696
Journal of Thrombosis and Thrombolysis - 相似文献
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.
Caterina Proto Daniela Romualdi Rosa Maria Cento Rosario S Spada Giuseppina Di Mento Raffaele Ferri Antonio Lanzone 《Gynecological endocrinology》2006,22(4):213-218
BACKGROUND: In the central nervous system, several neuropeptides are believed to be involved in the pathophysiology of Alzheimer's disease (AD). Indeed, previous studies have documented that glucagon-like peptide 1 (GLP-1) possesses neurotropic properties and can reduce amyloid-beta peptide levels in the brain in vivo. Moreover, the concentrations of neuropeptide Y (NPY) seem to be altered in the cerebrospinal fluid of patients with AD and in subjects with major depression. Finally, among the modifications induced by aging, a dysregulation of the ghrelin-growth hormone (GH) system has been reported. METHODS: We investigated the plasma concentrations of these neuropeptides in 14 subjects with AD. Data obtained from these patients were compared with data from an age- and weight-matched healthy group. RESULTS: No significant differences were found between the two groups in relation to plasma levels of GLP-1, NPY, ghrelin and GH. Peripheral NPY concentrations were positively correlated with ghrelin levels in both groups, and with plasma GLP-1 concentration only in controls. CONCLUSION: On the basis of our results, peripheral levels of these neuropeptides seem not to serve as biochemical markers of AD. 相似文献
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.
In vitro study of the antibacterial activity of ofloxacin against recent clinical isolates 总被引:1,自引:0,他引:1
The in vitro activity of ofloxacin, a new broad-spectrum antimicrobial agent, was studied by a standardized single disc method. A total of 990 clinical isolates were tested, including 20 strains of anaerobic bacteria. Ofloxacin was highly active against 683 strains (70.41%), had intermediate activity against 109 (11.23%) and had no activity against 178 (18.35%). Ofloxacin was highly active against E. coli, Klebsiella sp., Citrobacter sp., Proteus mirabilis, Proteus morganii, Salmonella sp., Campylobacter jejuni, Haemophilus influenzae, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Eubacterium sp., Propionibacterium acnes and Streptococcus sp. Pseudomonas sp., Serratia sp. and Proteus vulgaris had percentages of resistance to ofloxacin of 37.11%, 32% and 33.33% respectively. High percentages of resistance to ofloxacin were found only for Providencia sp., Proteus rettgeri and Bacteroides fragilis. With regard to Streptococcus faecalis, the results obtained with the disc procedure were not reliable and MIC determination was necessary to assess the behaviour of the drug. 相似文献
8.
9.
10.