全文获取类型
收费全文 | 124364篇 |
免费 | 8153篇 |
国内免费 | 535篇 |
专业分类
耳鼻咽喉 | 1326篇 |
儿科学 | 3708篇 |
妇产科学 | 2083篇 |
基础医学 | 16567篇 |
口腔科学 | 2259篇 |
临床医学 | 12278篇 |
内科学 | 26246篇 |
皮肤病学 | 1488篇 |
神经病学 | 12025篇 |
特种医学 | 3843篇 |
外国民族医学 | 1篇 |
外科学 | 17792篇 |
综合类 | 1731篇 |
现状与发展 | 1篇 |
一般理论 | 162篇 |
预防医学 | 10868篇 |
眼科学 | 3421篇 |
药学 | 8763篇 |
1篇 | |
中国医学 | 279篇 |
肿瘤学 | 8210篇 |
出版年
2023年 | 611篇 |
2022年 | 1070篇 |
2021年 | 2377篇 |
2020年 | 1420篇 |
2019年 | 2405篇 |
2018年 | 2815篇 |
2017年 | 2048篇 |
2016年 | 2390篇 |
2015年 | 2756篇 |
2014年 | 3975篇 |
2013年 | 5580篇 |
2012年 | 8507篇 |
2011年 | 9135篇 |
2010年 | 4987篇 |
2009年 | 4654篇 |
2008年 | 8069篇 |
2007年 | 8572篇 |
2006年 | 8120篇 |
2005年 | 8181篇 |
2004年 | 7712篇 |
2003年 | 7117篇 |
2002年 | 6861篇 |
2001年 | 1231篇 |
2000年 | 935篇 |
1999年 | 1263篇 |
1998年 | 1478篇 |
1997年 | 1242篇 |
1996年 | 967篇 |
1995年 | 956篇 |
1994年 | 816篇 |
1993年 | 799篇 |
1992年 | 699篇 |
1991年 | 640篇 |
1990年 | 559篇 |
1989年 | 520篇 |
1988年 | 518篇 |
1987年 | 499篇 |
1986年 | 439篇 |
1985年 | 517篇 |
1984年 | 592篇 |
1983年 | 539篇 |
1982年 | 715篇 |
1981年 | 620篇 |
1980年 | 543篇 |
1979年 | 380篇 |
1978年 | 355篇 |
1977年 | 361篇 |
1976年 | 303篇 |
1975年 | 282篇 |
1974年 | 285篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Liposome-mediated transfer of vascular endothelial growth factor cDNA augments survival of random-pattern skin flaps in the rat. 总被引:6,自引:0,他引:6
Paul Y Liu Wenjing Tong Kan Liu Sang Hoon Han Xiao Tian Wang Evangelos Badiavas Kimberly Rieger-Christ Ian Summerhayes 《Wound repair and regeneration》2004,12(1):80-85
Tissue engineering is an application for gene therapy that is in its infancy. We show that simple liposomal-mediated gene transfer could result in a potentially useful biological effect in the field of wound healing. cDNA encoding the 165 amino acid form of vascular endothelial growth factor complexed to commercially available liposomes was injected into rat skin 1 week before raising a random pattern 3 x 10 cm flap. The flap survival was enhanced by 14 percent, and was accomplished without accessing the arterial inflow of the territory. These results were statistically significant (p<0.002) and reproducible. No adverse effects were seen. Histological analysis of the angiogenesis localized much of the new vessel formation to the area around the hair follicles. Polymerase chain reaction amplification of extracted flap tissue confirmed the presence of the transgene. 相似文献
82.
In certain Japanese macaque (Macaca fuscata) populations, females routinely engage in same-sex courtship, mounting, and consortship activity. Drawing on behavioral,
biogeographic, and genetic research, we suggest that female homosexual behavior may be associated with genetically distinct
free-ranging populations of Japanese macaques. In addition, we briefly discuss the implications of this research for the evolution
of female homosexual behavior in this species. 相似文献
83.
84.
85.
86.
Christian J. Sauder Cheryl X. Zhang Malen A. Link W. Paul Duprex Kathryn M. Carbone Steven A. Rubin 《Vaccine》2009
The recent global resurgence of mumps has drawn attention to the continued need for robust mumps immunization programs. Unfortunately, some vaccines derived from inadequately attenuated vaccine strains of mumps virus have caused meningitis in vaccinees, leading to withdrawal of certain vaccine strains from the market, public resistance to vaccination, or in some cases, cessation of national mumps vaccination programs. The most widely implicated mumps vaccine in cases of postvaccination meningitis is derived from the Urabe AM9 strain, which remains in use in some countries. The Urabe AM9 vaccine virus has been shown to exhibit a considerable degree of nucleotide and amino acid heterogeneity. Some studies have specifically implicated variants containing a lysine residue at amino acid position 335 in the hemagglutinin-neuraminidase (HN) protein with neurotoxicity, whereas a glutamic acid residue at this position was associated with attenuation. To test this hypothesis we generated two modified Urabe AM9 cDNA clones coding either for a lysine or a glutamic acid at position 335 in the HN gene. The two viruses were rescued by reverse genetics and characterized in vitro and in vivo. Both viruses exhibited similar growth kinetics in neuronal and non-neuronal cell lines and were of similar neurotoxicity when tested in rats, suggesting that amino acid 335 is not a crucial determinant of Urabe AM9 growth or neurovirulence. 相似文献
87.
Histopathological characterisation of effects of the mouse Pax6 missense mutation on eye development
Thaya Ramaesh Steven E. Williams Catriona Paul Kanna Ramaesh John D. West 《Experimental eye research》2009,89(2):263-273
Mutations in PAX6/Pax6 lead to a variety of ocular anomalies in humans and mice. The aim of the study was to characterise the ocular abnormalities caused by the missense Pax6Leca4 mutation and compare them to published observations on Pax6 alleles that are functionally equivalent to Pax6− null alleles (such as Pax6Sey and Pax6Sey-Neu) and human inherited eye diseases. Ocular features of homozygous Pax6Leca4/Leca4 and heterozygous Pax6Leca4/+ embryos at E12.5-E18.5, heterozygous Pax6Leca4/+ young mice at P18 and heterozygous Pax6Leca4/+ adults at 12 weeks were analysed histologically with their wild-type Pax6+/+ littermates. Homozygous Pax6Leca4/Leca4 fetuses died perinatally with no eyes although an optic cup rudiment with pigmented cells developed. Pax6Leca4/+ mice were microphthalmic and a range of other severe ocular phenotypes affected both the anterior and the posterior segments. In contrast to Pax6+/−, the Pax6Leca4/+ eyes had no goblet cells in the corneal epithelium, the iris was not hypoplastic and there was no lens-corneal epithelial plug. However, microphthalmia was more severe, corneal vascularisation occurred earlier (during fetal stages), pigmented cells were present in the vitreous and corneal stroma and the ciliary body was malformed or abnormal. These results show that, although Pax6Leca4/+ lacked some eye abnormalities commonly seen in Pax6Sey/+ and Pax6Sey-Neu/+ eyes, in most respects their eyes were more severely affected. These differences probably reflect both differences between the Pax6Leca4 and the Pax6Sey-Neu mutations and differences in modifier gene expression in different genetic backgrounds. The presence of pigmented cells in the cornea is a novel observation. Some Pax6Leca4/+ ocular abnormalities were similar to those present in human Peters' anomaly and persistent hyperplastic primary vitreous (PHPV) so Pax6Leca4/+ mice provide a useful model for some inherited eye diseases. 相似文献
88.
89.
90.