全文获取类型
收费全文 | 369篇 |
免费 | 59篇 |
国内免费 | 149篇 |
出版年
2024年 | 6篇 |
2023年 | 11篇 |
2022年 | 17篇 |
2021年 | 20篇 |
2020年 | 26篇 |
2019年 | 34篇 |
2018年 | 15篇 |
2017年 | 23篇 |
2016年 | 11篇 |
2015年 | 24篇 |
2014年 | 25篇 |
2013年 | 23篇 |
2012年 | 37篇 |
2011年 | 34篇 |
2010年 | 38篇 |
2009年 | 23篇 |
2008年 | 27篇 |
2007年 | 26篇 |
2006年 | 20篇 |
2005年 | 19篇 |
2004年 | 15篇 |
2003年 | 23篇 |
2002年 | 11篇 |
2001年 | 18篇 |
2000年 | 9篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1977年 | 4篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有577条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Use of electroporation to introduce biologically active foreign genes into primary rat hepatocytes. 总被引:8,自引:2,他引:6
下载免费PDF全文
![点击此处可从《Molecular and cellular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R Tur-Kaspa L Teicher B J Levine A I Skoultchi D A Shafritz 《Molecular and cellular biology》1986,6(2):716-718
A method is described for introducing and expressing cloned genes in isolated hepatocytes. Primary rat hepatocytes isolated by collagenase perfusion were transfected in suspension with plasmid pSV2CAT by electroporation. Forty-eight hours later, soluble extracts from transfected hepatocytes showed chloramphenicol acetyltransferase activity comparable to that obtained in rat hepatoma cell line H4AzC2 by calcium phosphate or DEAE-dextran transfection. The latter two methods could not be used successfully for primary hepatocytes because of cytotoxicity of these reagents. This indicates that electroporation is a useful method to obtain transient expression of foreign genes in primary epithelial cells, such as rat hepatocytes, which are difficult to maintain in cell culture. 相似文献
5.
7.
Introduction of purified genes into mammalian cells 总被引:6,自引:0,他引:6
8.
X-linked control of hemoglobin production in somatic hybrids of mouse erythroleukemic cells and mouse lymphoma or bone marrow cells 总被引:7,自引:0,他引:7
Somatic cell hybrids were generated by fusion of mouse erythroleukemic cells (clone 745) to mouse lymphoma cells or mouse bone marrow cells. The erythroleukemic cells have been shown previously to have a low basal level of erythroid differentiation which is markedly amplified when the cells are grown in medium containing dimethylsulfoxide (DMSO). Hybrid cells were examined for hemoglobin production by benzidine staining. Many hybrid clones were found in which hemoglobin production in response to DMSO was either abolished or greatly reduced. From these hybrids, subclones were isolated in which hemoglobin production was restored. Karyological and enzyme analysis showed that the restoration of hemoglobin production was associated with the loss of an X chromosome contributed by the nonerythroleukemic parent. Other subclones which retained an X chromosome continued to be inhibited for hemoglobin production. Analysis of other hybrid lines capable of a limited degree of erythroid differentiation indicated a quantitative inverse correlation between the proportion of cells bearing an X chromosome and the proportion of cells able to form hemoglobin. Finally, four hybrid lines having many cells without an X chromosome were grown in medium containing DMSO. This procedure led to the selection of hybrid sublines having a nondifferentiating phenotype and concomitantly having a greatly increased proportion of cells bearing an X chromosome. Thus three lines of evidence suggest that a locus (loci) on the X chromosome is capable of inhibiting the DMSO-inducible hemoglobin production of the erythroleukemic cells. 相似文献
9.
Somatic cell hybrids between hepatoma and Friend erythroleukemia parental cells were studied for the expression of liver-specific and erythroid properties. Several independent clones were isolated using HAT selection and were shown to be true hybrids by isozyme and chromosome analysis. All displayed a complete extinction of hemoglobin and globin mRNA production, but a retention of albumin and transferrin secretion. The data suggest that erythroid differntiation is being actively inhibited by the hepatoma genome. Possible mechanisms that might explain these results are discussed in the light of current hypotheses regarding the mechanism of cell differentiation. 相似文献
10.