全文获取类型
收费全文 | 141篇 |
免费 | 11篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 4篇 |
基础医学 | 12篇 |
口腔科学 | 5篇 |
临床医学 | 14篇 |
内科学 | 34篇 |
皮肤病学 | 10篇 |
神经病学 | 5篇 |
特种医学 | 30篇 |
外科学 | 13篇 |
综合类 | 8篇 |
预防医学 | 4篇 |
眼科学 | 2篇 |
药学 | 6篇 |
肿瘤学 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 1篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 2篇 |
2007年 | 10篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 8篇 |
1975年 | 2篇 |
排序方式: 共有152条查询结果,搜索用时 0 毫秒
81.
82.
83.
84.
85.
86.
87.
88.
89.
Role of ADP-ribosyl transferase in differentiation of human granulocyte- macrophage progenitors to the macrophage lineage 总被引:6,自引:0,他引:6
Nuclear adenosine diphosphate-ribosyl (ADP-ribosyl) transferase is a chromatin-bound enzyme catalyzing the transfer of ADP-ribose from NAD+ to chromatin proteins. The physiologic function of this covalent modification of chromatin has not been fully established, but roles in both DNA repair and in differentiation have been proposed. We demonstrate that three specific inhibitors of ADP-ribosyl transferase (5-methylnicotinamide, 3-methoxybenzamide, 3-aminobenzamide) inhibit differentiation of human granulocyte-macrophage progenitor cells to the macrophage lineage. Differentiation to the neutrophil-granulocyte lineage is much less affected. The inhibition of macrophage differentiation seems to relate to the ability of these compounds to inhibit ADP-ribosyl transferase. A structural analogue (3- methoxybenzoic acid), which is not inhibitory for the enzyme, did not inhibit macrophage differentiation. Additional evidence for a role of ADP-ribosyl transferase in the differentiation of granulocyte- macrophage progenitors was obtained from experiments in which enzyme activity levels were measured in permeabilized marrow cells. Marrow cell ADP-ribosyl transferase activity increased after 3-hr stimulation by the differentiation/proliferation stimulus--granulocyte-macrophage colony-stimulating activity (GM-CSA). Unstimulated marrow cells showed low or undetectable levels of enzyme activity. 相似文献
90.
Estrogen-induced microsatellite DNA alterations are associated with Syrian hamster kidney tumorigenesis 总被引:4,自引:0,他引:4
Exposure to estrogens is associated with an increase in cancers, including
malignancies of the breast and uterus in humans, and of the kidney in
hamsters. DNA damage induced by metabolic activation of estrogen has been
postulated to result in gene mutations critical for the development of
estrogen-induced kidney tumors in hamsters. As part of our examination of
the genetic consequences of estrogen-induced DNA damage, we searched for
estrogen-induced alterations in microsatellite DNA, a frequent site of
mutation in tumors. Genomic DNA isolated from kidney of hamsters treated
with estradiol, from estrogen-induced kidney tumors and from untreated
age-matched controls, was examined by Southern blot analysis with three
multi-locus oligonucleotide probes: (GACA)4, (CAC)6 and (CAG)6. Alterations
in DNA fragments containing GACA and CAC tandem repeats were detected in
kidney DNA of hamsters treated with hormone for 3 and 4 months, whereas no
such effects were seen in control animals. In estrogen-induced tumors,
microsatellite alterations were observed in fragments that contain these
same two repeat sequences and also CAG repeat sequences. The induction of
microsatellite alterations by estradiol in kidney DNA preceding
estrogen-induced renal malignancy may play a role in hormone-induced
tumorigenesis.
相似文献