全文获取类型
收费全文 | 907篇 |
免费 | 41篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 33篇 |
妇产科学 | 34篇 |
基础医学 | 88篇 |
口腔科学 | 71篇 |
临床医学 | 49篇 |
内科学 | 113篇 |
皮肤病学 | 18篇 |
神经病学 | 41篇 |
特种医学 | 116篇 |
外科学 | 102篇 |
综合类 | 87篇 |
预防医学 | 55篇 |
眼科学 | 45篇 |
药学 | 60篇 |
肿瘤学 | 67篇 |
出版年
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 18篇 |
2020年 | 9篇 |
2019年 | 14篇 |
2018年 | 17篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 16篇 |
2014年 | 21篇 |
2013年 | 37篇 |
2012年 | 46篇 |
2011年 | 40篇 |
2010年 | 23篇 |
2009年 | 31篇 |
2008年 | 41篇 |
2007年 | 55篇 |
2006年 | 33篇 |
2005年 | 38篇 |
2004年 | 20篇 |
2003年 | 36篇 |
2002年 | 19篇 |
2001年 | 25篇 |
2000年 | 20篇 |
1999年 | 20篇 |
1998年 | 35篇 |
1997年 | 25篇 |
1996年 | 22篇 |
1995年 | 28篇 |
1994年 | 23篇 |
1993年 | 17篇 |
1992年 | 9篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 29篇 |
1988年 | 31篇 |
1987年 | 17篇 |
1986年 | 20篇 |
1985年 | 5篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 7篇 |
排序方式: 共有980条查询结果,搜索用时 15 毫秒
1.
2.
目的由于卒中风险随着狭窄严重程度的增加而升高,因此认为颈内动脉(ICA)接近闭塞患者的卒中风险很高。在现有的随机试验中,还没有专门针对这种情况进行探讨,因此其处理尚存在争汶。方法:对相关文献进行系统评价。结果:对ICA接近闭塞患者的处理还存在争议:一些学者支持进行干预,而另一些学者则认为存在风险或没有益处而反对进行干预。在ICA接近闭塞的有症状患者中进行一项比较外科治疗与最佳内科治疗的多中心前瞻性随机试验似乎非常困难,因为这类研究需要大量的患者。尽管如此,基于目前的证据,似乎很难拒绝手术治疗。结论:由于目前对ICA接近闭塞患者的最佳处理方案仍存在着争议,因此需要前瞻性观察性研究以证实其在有症状和无症状人群中的患病率以及相关的卒中风险。基于目前的证据,大多数医疗中心选择手术治疗,但它相对干内科治疗的特粱尚右待证章. 相似文献
3.
4.
5.
Rupture of the distal biceps tendon: evaluation with MR imaging 总被引:2,自引:0,他引:2
6.
7.
Partial seizures and migraine 总被引:1,自引:0,他引:1
D Mancia G C Manzoni M G Terzano G Pavesi M Marchini B Dalla Bernardina 《Functional neurology》1986,1(4):439-453
Epilepsy and migraine, despite some common features, have quite different pathophysiological mechanisms. Studies carried out on large population samples have shown that the relationships between migraine and epilepsy may be of the following type: associated attacks, with migraine and seizures occurring quite independently of one another; combined attacks, with the two types of attacks succeeding one another in time; basilar artery migraine with seizures and marked EEG abnormalities; benign epilepsies with occipital discharges, migraine and intercalated seizures. We report four cases of particular interest. 相似文献
8.
9.
Helicobacter pylori cytotoxin: importance of native conformation for induction of neutralizing antibodies. 总被引:22,自引:3,他引:19
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R Manetti P Massari D Burroni M de Bernard A Marchini R Olivieri E Papini C Montecucco R Rappuoli J L Telford 《Infection and immunity》1995,63(11):4476-4480
We have attempted to express the Helicobacter pylori vacuolating cytotoxin in Escherichia coli. Although the 95-kDa VacA polypeptide was expressed abundantly, it completely lacked any biological activity. In addition, this material failed to induce neutralizing antibodies after immunization of rabbits. In contrast, highly purified high-molecular-mass cytotoxin from the supernatant of H. pylori cultures was active in a HeLa cell assay and effectively induced a neutralizing response in rabbits. Neutralizing sera were shown to contain a high proportion of antibodies which recognized conformational epitopes found only on the native toxin. The data indicate that toxin-neutralizing epitopes are conformational and that potential vaccines based on the cytotoxin may benefit from the use of the intact molecule. 相似文献
10.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献