全文获取类型
收费全文 | 11391篇 |
免费 | 593篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 217篇 |
儿科学 | 372篇 |
妇产科学 | 206篇 |
基础医学 | 1328篇 |
口腔科学 | 316篇 |
临床医学 | 729篇 |
内科学 | 2941篇 |
皮肤病学 | 353篇 |
神经病学 | 741篇 |
特种医学 | 237篇 |
外国民族医学 | 1篇 |
外科学 | 1789篇 |
综合类 | 121篇 |
一般理论 | 4篇 |
预防医学 | 822篇 |
眼科学 | 299篇 |
药学 | 830篇 |
中国医学 | 50篇 |
肿瘤学 | 668篇 |
出版年
2023年 | 62篇 |
2022年 | 106篇 |
2021年 | 319篇 |
2020年 | 165篇 |
2019年 | 313篇 |
2018年 | 471篇 |
2017年 | 264篇 |
2016年 | 262篇 |
2015年 | 270篇 |
2014年 | 362篇 |
2013年 | 498篇 |
2012年 | 826篇 |
2011年 | 913篇 |
2010年 | 431篇 |
2009年 | 362篇 |
2008年 | 745篇 |
2007年 | 752篇 |
2006年 | 762篇 |
2005年 | 695篇 |
2004年 | 635篇 |
2003年 | 570篇 |
2002年 | 530篇 |
2001年 | 184篇 |
2000年 | 199篇 |
1999年 | 187篇 |
1998年 | 60篇 |
1997年 | 46篇 |
1996年 | 54篇 |
1995年 | 48篇 |
1994年 | 38篇 |
1993年 | 22篇 |
1992年 | 66篇 |
1991年 | 58篇 |
1990年 | 55篇 |
1989年 | 52篇 |
1988年 | 45篇 |
1987年 | 59篇 |
1986年 | 51篇 |
1985年 | 44篇 |
1984年 | 38篇 |
1983年 | 43篇 |
1982年 | 31篇 |
1981年 | 27篇 |
1980年 | 20篇 |
1979年 | 31篇 |
1978年 | 22篇 |
1977年 | 19篇 |
1975年 | 17篇 |
1974年 | 33篇 |
1973年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
The effect of fasting on hepatic lipase was studied during postnatal development in the rat. It was found that fasting produced a significant decrease in hepatic lipase only in neonatal (1-day-old) and adult (60-day-old) rats. We studied the effect of fasting on the distribution of hepatic lipase between extracellular (heparin-releasable) and intracellular (liver-retained or residual) compartments in perfused livers, and on the secretion of hepatic lipase by isolated hepatocytes. Fasting had similar effects in neonates and adults: it decreased both the heparin-releasing and the residual activities in perfused livers, and also decreased the rate of hepatic lipase secretion by isolated hepatocytes. Finally, the effect of fasting on hepatic lipase mRNA relative abundance in developing rat livers was determined. No difference was observed among the groups studied. It is concluded that the mechanisms involved in the effect of fasting on hepatic lipase appear to be similar in neonates and adult animals and may involve the post-translational processing of the enzyme. 相似文献
103.
Purpose:Morphological stability and functional integrity of corneal endothelium are necessary to maintain long-term corneal transparency. When the number of endothelial cells drops below 450–800 cells/mm2, corneal edema, irreversible loss of corneal transparency, and decreased vision occur. There is concern regarding manual small-incision cataract surgery (MSICS) being more harmful to the endothelium in comparison to phacoemulsification. Our study aims to determine which technique maintains the corneal parameters closest to the normal physiological state.Methods:A prospective observational study was conducted over a period of 15 months on 100 eyes, out of which 43 patients underwent phacoemulsification surgery and 57 underwent MSICS. TOPCON SP-1P, Version 1.41, 50–60 Hz frequency, noncontact specular microscope with pachymeter was used to measure endothelial cell count (ECC) and central corneal thickness (CCT) on four occasions: 1 day prior to surgery and on day 1, 3rd week, and 6th week after surgery.Results:In total, 100 eyes of 100 subjects were studied with no dropout during the study period. The age range was 40–70 years. There was no statistically significant difference between the preoperative mean ECC and mean CCT in phacoemulsification and SICS groups. A statistically significant difference was observed in the postoperative mean ECC (P < 0.01) and mean CCT (P < 0.001) on day 1 and 3rd week between the phacoemulsification and SICS groups, respectively. The mean endothelial cell loss at 6 weeks was less with SICS but comparable with phacoemulsification.Conclusion:SICS is significantly faster, less expensive, less technology dependent, can deal with all types of cataracts, is relatively safe, and is more appropriate for advanced cataracts. 相似文献
104.
Kerry L. Shannon Timothy Shields Sabeena Ahmed Hafizur Rahman Chai Shwai Prue Jacob Khyang Malathi Ram M. Zahirul Haq Jasmin Akter Mohammad Shafiul Alam Gregory E. Glass Myaing M. Nyunt David A. Sack David J. Sullivan Jr. Wasif A. Khan Frank C. Curriero 《The American journal of tropical medicine and hygiene》2022,107(6):1210
105.
106.
The kaolinite content is principally responsible for the durability performance of Limestone Calcined Clay Cement (LC3), which calls into question its global applicability. The clay supply has a significant impact on the LC3 system’s reduced carbon footprint advantage. The influence of kaolinite concentration from two separate clays (collected in East South-East Europe) on the durability performance of concrete was investigated in this study. The low-kaolinitic clay had 18% kaolinite, while the medium-kaolinitic clay contained around 41% kaolinite. The compressive strength, chloride intrusion, electrical conductivity, surface resistivity, and sorptivity index were measured on concrete after 28 days. Furthermore, the pore structure development of these mixtures was investigated in relation to the kaolinite content of the mixtures. The reactivity test was performed on clays to measure their reactivity levels within the cementitious system. The results show that kaolinite content has a moderate effect on compressive strength, but it has a considerable effect on other durability indices. When compared to the Portland cement mixture, the chloride migration and diffusion coefficients were reduced by 50% and 36%, respectively, in the combination with a medium kaolinite content (more than 40%). The low-kaolinitic clay, on the other hand, achieved 60% of the chloride penetration resistance of the medium-kaolinitic clay. Furthermore, low-kaolinitic clay has been demonstrated to be suitable for low-carbon concrete in moderate exposure conditions. 相似文献
107.
Alex Rebello Mohd Asif Kumbha Dhanusha Bandi Haritha Nangadda Narmada Ram Chandra Poudel 《Clinical Case Reports》2022,10(7)
We describe a patient who presented with fatigue and pulling sensation in his lower limbs. He had continuous muscle contractions over his trunk (myokymia) which pointed towards the diagnosis of Isaacs syndrome which was confirmed by strongly positive CASPR2 antibodies in blood. 相似文献
108.
109.
Redondo Alfredo Paradela-Dobarro Beatriz Moscoso Isabel Moure-Álvarez María Cebro-Márquez María González-Juanatey José Ramón García-Seara Javier Álvarez Ezequiel 《Journal of molecular medicine (Berlin, Germany)》2021,99(7):955-956
Journal of Molecular Medicine - A Correction to this paper has been published: https://doi.org/10.1007/s00109-021-02062-6 相似文献
110.