全文获取类型
收费全文 | 39804篇 |
免费 | 3673篇 |
国内免费 | 2108篇 |
专业分类
耳鼻咽喉 | 661篇 |
儿科学 | 563篇 |
妇产科学 | 854篇 |
基础医学 | 4547篇 |
口腔科学 | 637篇 |
临床医学 | 4665篇 |
内科学 | 6756篇 |
皮肤病学 | 827篇 |
神经病学 | 2201篇 |
特种医学 | 1369篇 |
外国民族医学 | 17篇 |
外科学 | 4028篇 |
综合类 | 5233篇 |
现状与发展 | 7篇 |
一般理论 | 7篇 |
预防医学 | 2667篇 |
眼科学 | 834篇 |
药学 | 4059篇 |
27篇 | |
中国医学 | 2220篇 |
肿瘤学 | 3406篇 |
出版年
2024年 | 133篇 |
2023年 | 608篇 |
2022年 | 1468篇 |
2021年 | 1969篇 |
2020年 | 1405篇 |
2019年 | 1392篇 |
2018年 | 1469篇 |
2017年 | 1306篇 |
2016年 | 1187篇 |
2015年 | 1827篇 |
2014年 | 2187篇 |
2013年 | 2177篇 |
2012年 | 3049篇 |
2011年 | 3194篇 |
2010年 | 2102篇 |
2009年 | 1538篇 |
2008年 | 2130篇 |
2007年 | 2023篇 |
2006年 | 1986篇 |
2005年 | 1921篇 |
2004年 | 1422篇 |
2003年 | 1339篇 |
2002年 | 1145篇 |
2001年 | 935篇 |
2000年 | 834篇 |
1999年 | 761篇 |
1998年 | 469篇 |
1997年 | 423篇 |
1996年 | 340篇 |
1995年 | 311篇 |
1994年 | 279篇 |
1993年 | 202篇 |
1992年 | 332篇 |
1991年 | 284篇 |
1990年 | 219篇 |
1989年 | 171篇 |
1988年 | 193篇 |
1987年 | 159篇 |
1986年 | 123篇 |
1985年 | 117篇 |
1984年 | 84篇 |
1983年 | 44篇 |
1982年 | 25篇 |
1981年 | 35篇 |
1980年 | 21篇 |
1979年 | 32篇 |
1978年 | 24篇 |
1977年 | 19篇 |
1975年 | 18篇 |
1973年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
91.
92.
单片微机化微弱发光测量仪及其在肿瘤研究中的初步应用 总被引:2,自引:0,他引:2
单片微机化微弱发光测量仪由中科院生物物理所和北京科龙生物医学技术开发公司研制成功。该仪器适用于肿瘤研究中生物医学样品的微弱发光的测量。测量样品的重复性优于0.8%,稳定性优于0.5%,线性相关系数达0.9997,不仅可以进行样品的发光强度测量,还可以进行动力学曲线的测量以及样品发射光谱的测量。光谱在400nm-750nm范围内。测量方式可选择手动、半自动和自动计时三种。测量结果表明,荷瘤裸鼠血液微 相似文献
93.
94.
We report here the preliminary effects of zinc iontophoresis in treatment of 26 Rp patients who had decreased zinc serum level or abnormal ratio of serum copper to zinc. Through more than 20 to 30 times of therapy, the vision of 15.38% eyes increased more than "3 lines", 4% eyes increased more than 5 degrees in the visual field, 13.46% eyes improved in dark adaptation threshold (greater than 1.0), the visual functions of the rest eyes were slightly improved or unimproved. The fundus didn't change before & after treatment. There were no changes of ERG in 8 eyes of 4 cases. In addition, the advantages and disadvantages between Zn iontophoresis and Zn compound taken orally, the improvement of vision by direct electric current therapy, the relationship between the metabolism of Zn element and Vit A and influence of Zn over the mechanism of dark adaptation were also briefly discussed. 相似文献
95.
注射用克林霉素磷酸酯的稳定性研究 总被引:2,自引:0,他引:2
目的:对影响注射用克林霉素磷酸酯稳定性的各种因素进行考察,方法:采用高效液相色谱法测定注射用克林霉素磷酸酯的稳定性。结果:温度对本制剂稳定性有影响,对光稳定性较好。结论:本制剂应于凉暗干燥处贮存。 相似文献
96.
97.
一氧化氮对慢性鼻窦炎鼻息肉粘膜上皮细胞纤毛运动的影响 总被引:2,自引:0,他引:2
OBJECTIVE: To investigate the effect of nitric oxide on ciliary beat frequency in human nasal mucosa. METHOD: A primary culture model of human nasal mucosa epithelial cells was established and the effect of nitric oxide on ciliary beat frequency was observed by videomicroscopy method. The data were statistically analyzed using t-test. RESULT: L-arginine significantly increased ciliary beat frequency from (400 +/- 48) beats/min to (793 +/- 68) beats/min (n = 9, P < 0.001), D-arginine had no similar effect, while NOS blocker L-NAME inhibited the effect of L-arginine. CONCLUSION: Cells cultured by our method could synthesize NOS that made L-arginine produce NO that could increase ciliary beat frequency in the human nasal mucosa. 相似文献
98.
Xueping Yu Yijuan Zheng Dawu Zeng Yongjun Zhou Jian Sun Milong Su Huatang Zhang Minhui Zheng Zhipeng Huang Wenwu Lin Richeng Mao Jiming Zhang Chunfu Zheng Zhijun Su 《Journal of medical virology》2023,95(1):e28129
CD7 and CD57 are related to the differentiation and functional stages of CD8+ T cells. However, the role of their combined presence in CD8+ T cells in patients with chronic hepatitis B virus (HBV) infection, especially those with end-stage liver disease, remains unclear. Blood samples from healthy volunteers and patients with chronic hepatitis B were analyzed via Luminex assay and ELISA to measure plasma cytokine levels. Further, recombinant IL-22 was used to stimulate peripheral blood mononuclear cells from healthy volunteers, and the frequency of CD3+CD4−CD7+CD57− T cells and apoptosis rates were investigated via flow cytometry. Patients with end-stage liver disease, particularly those with acute to chronic liver failure, showed decreased CD3+CD4−CD7+CD57− T cell frequency. Furthermore, the prevalence of CD3+CD4−CD7+CD57− T cells was negatively correlated with disease severity, prognosis, and complications (ascites). We also observed that IL-22 promoted apoptosis and brought about a decrease in the number of CD3+CD4−CD7+CD57− T cells in a dose-dependent manner. CD3+CD4−CD7+CD57− T cells displayed a B and T lymphocyte attenuator (BTLA)highCD25highCD127high immunosuppressive phenotype and showed low interferon-γ, tumor necrosis factor-α, granzyme A, and perforin expression levels. The present findings will elucidate the pathogenesis of HBV-related end-stage liver disease and aid the identification of novel drug targets. 相似文献
99.
人流术中应用异丙酚与复合应用氯胺酮的比较 总被引:2,自引:0,他引:2
本实验旨在探讨微量氯胺酮与异丙酚联合应用的效果,以期获得更安全、更适合门诊手术的麻醉方式。 作者简介:郭晓丽(1963-),女,河南省新乡市人,硕士研究生,主治医师,讲师,主要从事麻醉镇痛方面的研究,发表论文5篇。电话:(023)68757347 收稿日期:20000508;修回日期:200010201 资料与方法 研究对象:60例停经8~12周的早期妊娠妇女,年龄17~43岁,体重40~77kg,ASAⅠ~Ⅱ级,术前禁食6h,禁饮4h。麻醉前20min肌注阿托品0.5mg。随机分为两组,异丙酚+氯胺酮组(PK组,n=30例);异丙酚组(P组,n=30例麻醉方法:PK组:异丙酚1~… 相似文献
100.