全文获取类型
收费全文 | 201篇 |
免费 | 14篇 |
出版年
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 12篇 |
2014年 | 9篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 14篇 |
2010年 | 4篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 6篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 10篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有215条查询结果,搜索用时 13 毫秒
41.
C Loetchutinat W Priebe A Garnier-Suillerot 《European journal of biochemistry》2001,268(16):4459-4467
Cells that acquire multidrug resistance (MDR) are characterized by a decreased accumulation of a variety of drugs. In addition, sequestration of drugs in intracellular vesicles has often been associated with MDR. However, the nature and role of intracellular vesicles in MDR are unclear. We addressed the relationship between MDR and vesicular anthracycline accumulation in the erythroleukemia cell line K562 and a drug-resistant counterpart K562/ADR that overexpresses P-glycoprotein. We used four anthracyclines (all of which are P-glycoprotein substrates): daunorubicin and idarubicin, which have good affinity for DNA and as weak bases can accumulate inside acidic compartments; hydroxyrubicin, which binds to DNA but is uncharged at physiological or acidic pH and thus cannot accumulate in acidic compartments; and WP900, an enantiomer of daunorubicin, which is a weak DNA binder but has the same pKa and lipophilicity as daunorubicin. The intrinsic fluorescence of anthracyclines allowed us to use macro- and micro-spectrofluorescence, flow cytometry, and confocal microscopy to characterize their nuclear or intravesicular accumulation in living cells. We found that vesicular accumulation of daunorubicin, WP900 and idarubicin, containing a basic 3'-amine was predominantly restricted to lysosomes in both cell lines, that pH regulation of acidic compartments was not defective in human K562 cells, and that vesicular drug accumulation was much more pronounced in the parental tumor cell line than in the multidrug-resistant cells. These results indicate that vesicular anthracycline sequestration does not contribute to the diminished sensitivity to anthracyclines in multidrug-resistant K562 cells. 相似文献
42.
43.
On association in a copula with time transformations 总被引:2,自引:0,他引:2
44.
45.
46.
47.
David A. Belford Mary-Louise Rogers Geoffrey O. Regester Geoffrey L. Francis Geoffrey W. Smithers Ingrid J. Liepe Ilka K. Priebe F. John Ballard 《In vitro cellular & developmental biology. Animal》1995,31(10):752-760
Summary We have investigated the response of several epithelial and fibroblastic cells to a mitogenic extract of bovine milk. Cation
exchange chromatography was used to produce a mitogen-rich fraction from an industrial whey source that, although comprising
only 0.5% of total whey protein, contained the bulk of the growth factor activity. This fraction was a source of potent growth
promoting activity for all mesodermal-derived cells tested, including human skin and embryonic lung fibroblasts, Balb/c 3T3
fibroblasts, and rat L6 myoblasts. Maximal growth of all these cell types exceeded that observed in 10% fetal bovine serum.
Feline kidney and baby hamster fibroblasts and Chinese hamster ovary cells were less responsive, achieving a maximal growth
response of 50–75% that observed in 10% fetal bovine serum. Maximal growth achieved in whey-extract-supplemented cultures
of Balb/c 3T3 and human skin fibroblasts, and L6 myoblast cultures exceeded that seen in response to recombinant acidic or
basic fibroblast growth factor, platelet-derived growth factor, insulin-like growth factor, or epidermal growth factor. Importantly,
addition of low concentrations of fetal bovine serum to the whey-derived mitogenic fraction produced an additive response.
However, concentrated milk-derived factors were found to be inhibitory to the growth of all epithelial lines tested, including
rat intestinal epithelial cells, canine kidney epithelial cells, and mink lung cells. It is concluded that industrial whey
extracted in this form constitutes an important source of potent growth-promoting agents for the supplementation of mesodermal-derived
cell cultures. 相似文献
48.
49.
In the course of a freeze-cleave study on intercellular junctions in the regenerating rat liver, we observed an unusual array of intramembranous particles located in regions of contact between endothelial cells lining the hepatic sinusoids. These arrays were characterized by an accumulation of particles which resembled a zonula occludens in their linear deployment but differed in that the contact regions were composed of individual particles which remained separated from each other by regular particle-free intervals. 相似文献
50.