全文获取类型
收费全文 | 978篇 |
免费 | 78篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 56篇 |
妇产科学 | 14篇 |
基础医学 | 131篇 |
口腔科学 | 38篇 |
临床医学 | 99篇 |
内科学 | 194篇 |
皮肤病学 | 34篇 |
神经病学 | 23篇 |
特种医学 | 139篇 |
外科学 | 89篇 |
综合类 | 37篇 |
预防医学 | 49篇 |
眼科学 | 50篇 |
药学 | 60篇 |
中国医学 | 2篇 |
肿瘤学 | 50篇 |
出版年
2022年 | 4篇 |
2021年 | 17篇 |
2020年 | 12篇 |
2019年 | 17篇 |
2018年 | 12篇 |
2017年 | 22篇 |
2016年 | 18篇 |
2015年 | 29篇 |
2014年 | 27篇 |
2013年 | 35篇 |
2012年 | 17篇 |
2011年 | 17篇 |
2010年 | 55篇 |
2009年 | 38篇 |
2008年 | 23篇 |
2007年 | 33篇 |
2006年 | 22篇 |
2005年 | 28篇 |
2004年 | 24篇 |
2003年 | 21篇 |
2002年 | 17篇 |
2001年 | 15篇 |
2000年 | 21篇 |
1999年 | 29篇 |
1998年 | 54篇 |
1997年 | 46篇 |
1996年 | 40篇 |
1995年 | 25篇 |
1994年 | 35篇 |
1993年 | 29篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 12篇 |
1989年 | 25篇 |
1988年 | 21篇 |
1987年 | 23篇 |
1986年 | 18篇 |
1985年 | 15篇 |
1984年 | 11篇 |
1983年 | 11篇 |
1982年 | 16篇 |
1981年 | 10篇 |
1980年 | 18篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 14篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 4篇 |
1970年 | 4篇 |
排序方式: 共有1071条查询结果,搜索用时 375 毫秒
1.
Isolating the color vision loss in primary open-angle glaucoma 总被引:15,自引:0,他引:15
We evaluated the results of Farnsworth-Munsell 100-Hue tests in age- and lens density-matched eyes of normal subjects, glaucoma suspects, and patients with primary open-angle glaucoma. With these controls in place, no significant correlation between the test results and age or between the test results and lens density was found. However, a significant difference in the total error scores on the 100-Hue test remained. This difference could not be explained by pupil size or medications taken. We concluded that color vision loss in glaucoma is in part attributable to the disease process and cannot be explained solely on the basis of changes in age and lens density. 相似文献
2.
Monoclonal origin of vulvar intraepithelial neoplasia and some vulvar hyperplasias. 总被引:2,自引:1,他引:1
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J. E. Tate G. L. Mutter K. A. Boynton C. P. Crum 《The American journal of pathology》1997,150(1):315-322
Squamous neoplasms of the female genital tract, including vulvar intraepithelial neoplasia, presumably are derived from a single cell. This study addressed this hypothesis and determined the clonal status of other squamous epithelial alterations associated with vulvar carcinoma, including hyperplasia and lichen sclerosis. X chromosome inactivation patterns of 22 epithelial lesions and matched normal epithelium were determined using a polymerase chain reaction (PCR)-based assay targeting the X-linked human androgen receptor gene (HUMARA). Clonality was inferred by comparing matched lesional and control tissues as follows: 1) monoclonal, if intensity of either PCR product was skewed relative to normal reference epithelium (control), 2) polyclonal, if both lesional and control were unskewed, and 3) unknown, if both lesion and control tissues were skewed toward the same allele. Two cases were excluded because of noninformative homozygous HUMARA alleles. Of 8 vulvar intraepithelial neoplasias analyzed, 7 were scored monoclonal and 1 polyclonal. Of 12 hyperplasias, 6 were monoclonal, including one with lichen sclerosis, 2 were polyclonal, and in 4, the clonal status could not be determined. The PCR-based clonal assay supports a monoclonal derivation for vulvar intraepithelial neoplasia and, in some cases, vulvar hyperplasia, and lichen sclerosis. The finding of monoclonal hyperplasia and lichen sclerosis suggests that clonal expansion may evolve before the development of morphological atypia in these epithelia. 相似文献
3.
4.
Summary Meiotic progeny of Chlamydomonas reinhardtii normally receive chloroplast genomes only from the mt
+ parent. However, exceptional zygotes, which transmit the chloroplast genomes of both parents or, more rarely, only those of the mt
- parent, arise at a low frequency. Mutations at the mt
+-linked mat-3 locus were found previously to elevate the transmission of chloroplast genomes from the mt-parent, resulting in a much higher than normal frequency of exceptional zygotes. In this paper we demonstrate that an ultraviolet-sensitive nuclear mutation mapping at the uvsE1 locus, which is unlinked to mating type, also promotes chloroplast genome transmission from the mt
- parent. This mutant, which was previously shown to reduce recombination of nuclear genes in meiosis, acts synergistically which the mat3-3 mutation to produce an extremely high frequency of exceptional zygotes. Through the use of restriction fragment length polymorphisms existing in the chloroplast genomes of C. reinhardtii and the interfertile strain C. smithii, we show that chloroplast DNA fragments from the mt
- parent normally begin to disappear shortly after zygote formation. However, this process appears to be blocked totally in the absence of wild-type uvsE1 and mat-3 gene products. Our findings are consistent with the hypothesis that both gene products contribute to the mechanism responsible for uniparental inheritance of the chloroplast genome from the mt
+ parent. 相似文献
5.
GP SCHWAB AL BLUM E BODNER B DALLEMAGNE K GLASER H KOOP F PACE W RÖSCH JR SIEWERT G WETSCHER 《Journal of gastroenterology and hepatology》1997,12(12):785-789
Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper. 相似文献
6.
7.
8.
Edward?J?HolloxEmail author Jane?Davies Uta?Griesenbach Juliana?Burgess Eric?WFW?Alton John?AL?Armour 《Journal of negative results in biomedicine》2005,4(1):9
Human beta-defensin 2 (DEFB4, also known as DEFB2 or hBD-2) is a salt-sensitive antimicrobial protein that is expressed in
lung epithelia. Previous work has shown that it is encoded in a cluster of beta-defensin genes at 8p23.1, which varies in
copy number between 2 and 12 in different individuals. We determined the copy number of this locus in 355 patients with cystic
fibrosis (CF), and tested for correlation between beta-defensin cluster genomic copy number and lung disease associated with
CF. No significant association was found. 相似文献
9.
Missense FGFR3 mutations create cysteine residues in thanatophoric dwarfism type I (TD1) 总被引:10,自引:1,他引:10
Rousseau F; el Ghouzzi V; Delezoide AL; Legeai-Mallet L; Le Merrer M; Munnich A; Bonaventure J 《Human molecular genetics》1996,5(4):509-512
Thanatophoric dwarfism (TD) is a sporadic lethal skeletal dysplasia with
micromelic shortening of the limbs, macrocephaly, platyspondyly and reduced
thoracic cavity. In the most common subtype (TD1), femurs are curved, while
in TD2, straight femurs are associated with cloverleaf skull. Mutations in
the fibroblast growth factor receptor 3 (FGFR3) gene were identified in
both subtypes. While TD2 was accounted for by a single recurrent mutation
in the tyrosine kinase 2 domain, TD1 resulted from either stop codon
mutations or missense mutations in the extracellular domain of the gene.
Here, we report the identification of FGFR3 mutations in 25/26 TD cases.
Two novel missense mutations (Y373C and G370C) were detected in 8/26 and
1/26 TD1 cases respectively. Both mutations created cysteine residues in
the juxta extramembrane domain of the receptor. Sixteen cases carried the
previously reported R248C (9/26 cases), S249C (2/26 cases) or stop codon
FGFR3 mutations (5/26 cases). Our results suggest that TD1 is a genetically
homogeneous condition and give additional support to the view that newly
created cysteine residues in the extracellular domain of the protein play a
key role in the severity of the disease.
相似文献
10.
Meiotic progeny of Chlamydomonas reinhardtii normally receive chloroplast genomes only from the mt+ parent. However, exceptional zygotes, which transmit the chloroplast genomes of both parents or, more rarely, only those of the mt- parent, arise at a low frequency. Mutations at the mt(+)-linked mat-3 locus were found previously to elevate the transmission of chloroplast genomes from the mt- parent, resulting in a much higher than normal frequency of exceptional zygotes. In this paper we demonstrate that an ultraviolet-sensitive nuclear mutation mapping at the uvsE1 locus, which is unlinked to mating type, also promotes chloroplast genome transmission from the mt- parent. This mutant, which was previously shown to reduce recombination of nuclear genes in meiosis, acts synergistically with the mat-3-3 mutation to produce an extremely high frequency of exceptional zygotes. Through the use of restriction fragment length polymorphisms existing in the chloroplast genomes of C. reinhardtii and the interfertile strain C. smithii, we show that chloroplast DNA fragments from the mt- parent normally begin to disappear shortly after zygote formation. However, this process appears to be blocked totally in the absence of wild-type uvsE1 and mat-3 gene products. Our findings are consistent with the hypothesis that both gene products contribute to the mechanism responsible for uniparental inheritance of the chloroplast genome from the mt+ parent. 相似文献