全文获取类型
收费全文 | 622篇 |
免费 | 45篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 83篇 |
儿科学 | 17篇 |
妇产科学 | 10篇 |
基础医学 | 86篇 |
口腔科学 | 21篇 |
临床医学 | 33篇 |
内科学 | 84篇 |
皮肤病学 | 107篇 |
神经病学 | 5篇 |
特种医学 | 91篇 |
外科学 | 44篇 |
综合类 | 21篇 |
预防医学 | 20篇 |
眼科学 | 2篇 |
药学 | 18篇 |
肿瘤学 | 29篇 |
出版年
2021年 | 6篇 |
2019年 | 7篇 |
2018年 | 12篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 19篇 |
2014年 | 14篇 |
2013年 | 31篇 |
2012年 | 25篇 |
2011年 | 15篇 |
2010年 | 23篇 |
2009年 | 18篇 |
2008年 | 24篇 |
2007年 | 21篇 |
2006年 | 20篇 |
2005年 | 12篇 |
2004年 | 11篇 |
2002年 | 5篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 22篇 |
1997年 | 23篇 |
1996年 | 16篇 |
1995年 | 14篇 |
1994年 | 15篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 13篇 |
1989年 | 17篇 |
1988年 | 11篇 |
1987年 | 9篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1981年 | 7篇 |
1980年 | 13篇 |
1979年 | 10篇 |
1978年 | 15篇 |
1977年 | 11篇 |
1976年 | 6篇 |
1975年 | 10篇 |
1974年 | 6篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1970年 | 5篇 |
1969年 | 6篇 |
1968年 | 8篇 |
1967年 | 4篇 |
排序方式: 共有671条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Michio Shimamura Toshiaki Ohteki Ulrich Beutner H. Robson MacDonald 《European journal of immunology》1997,27(6):1576-1579
NK1.1+ T cells are an unusual subset of TCRαβ cells distinguished by their highly restricted Vβ repertoire and predominant usage of an invariant Vα14-Jα281 chain. To assess whether a directed rearrangement mechanism could be responsible for this invariant α chain, we have analyzed Vα14 rearrangements by polymerase chain reaction and Southern blot in a panel of cloned T-T hybrids derived from thymic NK1.1+ T cells. As expected a high proportion (17/20) of the hybrids had rearranged Vα14 to Jα281. However, Vα14-Jα281 rearrangements always occurred on only one chromosome and were accompanied by other Vα-Ja rearrangements (not involving Vα14) on the homologous chromosome. These data argue that rigorous ligand selection rather than directed rearrangement is responsible for the high frequency of Vα14-Jα281 rearrangements in NK1.1+ T cells. 相似文献
6.
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
7.
In a child with some features of Turner's syndrome, gonosomal mosaicism with an isodicentric nonfluorescent (idic)Y chromosome was detected (mos 45,X/47,X,idic(Y)(q11),idic(Y)(11)/46,X,idic(Y)(q11)). Histopathological examination showed streak gonads with some evidence of ovarian stroma and no sign of gonadoblastoma. Polymerase chain reaction (PCR) analysis in blood lymphocytes and gonadal tissues using primers of seven loci along the Y chromosome, including the sex determined region (SRY), azoospermia factor region (AZF) and the deleted in azoospermia ( DAZ ) gene was positive for all loci tested, confirming the isodicentric character of the Y chromosome and indicating the presence of the AZF region. It is remarkable that the existence of spermatogenesis controlling genes does not play an important role in gonadal development and differentiation in a phenotypic female with some Turner stigmata. The data presented here are briefly discussed with previously-described patients. 相似文献
8.
Autoimmunity in chronic bullous skin diseases. Immunofluorescent demonstration of three types of antibodies to skin in sera of patients with pemphigus, bullous pemphigoid and in other human sera 总被引:1,自引:0,他引:1 下载免费PDF全文
E. H. Beutner Ellen L. Rhodes E. J. Holborow 《Clinical and experimental immunology》1967,2(2):141-151
Antibodies to an intercellular substance of epidermis and other stratified squamous epithelia demonstrable by immunofluorescent staining have been reported to occur in the sera of patients with pemphigus vulgaris. Using sera of patients with bullous pemphigoid, antibodies to a component of the basement zone of skin had been found by the same technique. In the present study these observations have been confirmed and extended. In addition to the above mentioned immunofluorescent staining reactions, another type of antibody directed to a cytoplasmic or perinuclear component of epidermal cells was found in a variety of pathologic sera. This observation points to the need for differentiating other skin-reactive antibodies from those found only in pemphigus. Guinea-pig lip sections appeared to be satisfactory for these studies. Mixed immunofluorescence was found to yield staining reactions identical to those observed by the indirect staining method, and gave titres the same as or lower than those obtained by the indirect staining procedure. Using the indirect method with guinea-pig lip sections it was found that eight of ten sera of patients with pemphigus contained intercellular antibodies while 102 control sera failed to yield reactions of this type. The titres of antibodies appeared to be proportional to the severity of the disease process. Sera of two out of three patients suffering from bullous pemphigoid yielded immunofluorescence staining of the basement zone while 109 controls were negative for this antibody. 相似文献
9.
Renal transplant (RT) is now a therapy of choice for end stage renal disease (ESRD). The Nephrology Unit, Asvini started functioning in Dec 90 and to date 1298 sittings of hemodialysis have been given to 45 patients. Of these, 35 were in ESRD and 11 patients underwent renal transplantation at this hospital during the period Jan 91 – Dec 93. One patient expired after 18 months of transplantation due to infection. Early experience in screening patients for RT, use of immunosuppression, management of rejection episodes and protocol are presented with special emphasis on its relevance to the Armed Forces.KEY WORDS: Transplantation, Renal Failure, Immunosuppression, Rejection 相似文献
10.