全文获取类型
收费全文 | 1930篇 |
免费 | 116篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 136篇 |
妇产科学 | 36篇 |
基础医学 | 169篇 |
口腔科学 | 19篇 |
临床医学 | 232篇 |
内科学 | 413篇 |
皮肤病学 | 67篇 |
神经病学 | 56篇 |
特种医学 | 278篇 |
外科学 | 184篇 |
综合类 | 53篇 |
预防医学 | 145篇 |
眼科学 | 137篇 |
药学 | 108篇 |
中国医学 | 6篇 |
肿瘤学 | 66篇 |
出版年
2023年 | 11篇 |
2022年 | 9篇 |
2021年 | 16篇 |
2020年 | 21篇 |
2019年 | 32篇 |
2018年 | 29篇 |
2017年 | 21篇 |
2016年 | 27篇 |
2015年 | 28篇 |
2014年 | 38篇 |
2013年 | 50篇 |
2012年 | 68篇 |
2011年 | 67篇 |
2010年 | 54篇 |
2009年 | 90篇 |
2008年 | 70篇 |
2007年 | 109篇 |
2006年 | 67篇 |
2005年 | 58篇 |
2004年 | 49篇 |
2003年 | 43篇 |
2002年 | 41篇 |
2001年 | 53篇 |
2000年 | 65篇 |
1999年 | 33篇 |
1998年 | 100篇 |
1997年 | 74篇 |
1996年 | 68篇 |
1995年 | 68篇 |
1994年 | 50篇 |
1993年 | 47篇 |
1992年 | 44篇 |
1991年 | 33篇 |
1990年 | 44篇 |
1989年 | 50篇 |
1988年 | 51篇 |
1987年 | 43篇 |
1986年 | 34篇 |
1985年 | 30篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1982年 | 23篇 |
1981年 | 12篇 |
1980年 | 17篇 |
1979年 | 13篇 |
1978年 | 12篇 |
1977年 | 18篇 |
1976年 | 19篇 |
1975年 | 13篇 |
1971年 | 8篇 |
排序方式: 共有2122条查询结果,搜索用时 15 毫秒
101.
102.
103.
Keay L Edwards K Brian G Naduvilath T Stapleton F 《Clinical & experimental ophthalmology》2004,32(4):349-353
PURPOSE: To evaluate surveillance methods in a pilot epidemiological study of contact lens related microbial keratitis (MK) cases identified by ophthalmic practitioners in Australia and New Zealand between May and August 2003 inclusive. METHODS: Twelve ophthalmologists and 55 optometrists from rural and metropolitan locations were sent a study information pack with postal reporting forms. After 2 months, practitioners were emailed a link to a website for Internet reporting. After 4 months, practitioners were prompted by email and then by telephone if a response was not received. Passive response rates were the rate of returns after posting information and emailing the website link. Active response rates included personalized email and telephone follow-up. RESULTS: Ten cases of MK were identified by optometrists and five by ophthalmologists. The passive response rates were 79% and 58% for the first and second reporting periods, respectively. There was a lower response rate in the second reporting period compared to the first (P = 0.02). With active surveillance the response rate increased to 97% and 96%. A large proportion of optometrists (62%) and ophthalmologists (55%) used the website for at least one reporting period. Internet reporting was used by all New Zealand practitioners (5/5). CONCLUSIONS: A surveillance study to estimate the incidence of contact lens related MK in Australia and New Zealand is feasible and acceptable. Internet-based reporting offers a reliable, rapid and cost-effective means of running a large scale, international surveillance study. Active surveillance methods are necessary to enhance reporting rates. 相似文献
104.
105.
106.
107.
108.
Cloning and expression of the gene involved in Sanfilippo B syndrome (mucopolysaccharidosis III B) 总被引:4,自引:1,他引:4
Sanfilippo B syndrome is caused by a deficiency of alpha-N-
acetylglucosaminidase, a lysosomal enzyme involved in the degradation of
heparan sulphate. Accumulation of the substrate in lysosomes results in
degeneration of the central nervous system with progressive dementia often
combined with hyperactivity and aggressive behaviour. In order to clone the
deficient gene, we purified the enzyme from human placenta and obtained
amino acid sequence information. Alignment of one of the CNBr generated
internal peptides to sequence from the database revealed the chromosomal
location of the gene in the 5' upstream flanking region of the gene for
17-beta-hydroxysteroid-dehydrogenase at 17q21.1. The available DNA sequence
was used to clone the cDNA coding for alpha-N- acetylglucosaminidase and
analyse its gene structure. The gene is fully contained in the 5' upstream
flanking region of the gene for 17-beta- hydroxysteroid-dehydrogenase and
interrupted by five introns. The cDNA clone has a length of 2575 bp and
encodes a protein of 743 amino acids. Chinese hamster ovary cells
transfected with the cDNA construct show alpha-N-acetylglucosaminidase
activity about 17-fold over background. This will allow correction studies
with NAG deficient Sanfilippo B cell lines and facilitate the development
of enzyme replacement therapy for these patients.
相似文献
109.
Regenhardt Robert W. Turner Ashby C. Hirsch Joshua A. Young Michael J. Alotaibi Naif M. Stapleton Christopher J. Patel Aman B. Leslie-Mazwi Thabele M. Rost Natalia S. Etherton Mark R. 《Journal of neurology》2022,269(1):307-315
Journal of Neurology - Sex-specific differences in ischemic stroke outcomes are prevalent. We sought to investigate sex differences in the determinants of reperfusion and functional outcomes after... 相似文献
110.