全文获取类型
收费全文 | 392篇 |
免费 | 50篇 |
出版年
2022年 | 4篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 11篇 |
2012年 | 20篇 |
2011年 | 9篇 |
2010年 | 13篇 |
2009年 | 9篇 |
2008年 | 13篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 8篇 |
2004年 | 20篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 13篇 |
2000年 | 23篇 |
1999年 | 12篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1995年 | 5篇 |
1992年 | 7篇 |
1991年 | 15篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1974年 | 7篇 |
1972年 | 7篇 |
1971年 | 5篇 |
1970年 | 6篇 |
1968年 | 4篇 |
1967年 | 8篇 |
1966年 | 8篇 |
1965年 | 3篇 |
1964年 | 3篇 |
1953年 | 3篇 |
1951年 | 4篇 |
排序方式: 共有442条查询结果,搜索用时 14 毫秒
41.
Chimeric Human Immunodeficiency Virus Type 1 Containing Murine Leukemia Virus Matrix Assembles in Murine Cells
下载免费PDF全文
![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Margaret Reed Roberto Mariani Liana Sheppard Katja Pekrun Nathaniel R. Landau Nay-Wei Soong 《Journal of virology》2002,76(1):436-443
Murine cells do not support efficient assembly and release of human immunodeficiency virus type 1 (HIV-1) virions. HIV-1-infected mouse cells that express transfected human cyclin T1 synthesize abundant Gag precursor polyprotein, but inefficiently assemble and release virions. This assembly defect may result from a failure of the Gag polyprotein precursor to target to the cell membrane. Plasma membrane targeting of the precursor is mediated by the amino-terminal region of polyprotein. To compensate for the assembly block, we substituted the murine leukemia virus matrix coding sequences into an infectious HIV-1 clone. Transfection of murine fibroblasts expressing cyclin T1 with the chimeric proviruses resulted in viruses that were efficiently assembled and released. Chimeric viruses, in which the cytoplasmic tail of the transmembrane subunit, gp41, was truncated to prevent potential interference between the envelope glycoprotein and the heterologous matrix, could infect human and murine cells. They failed to further replicate in the murine cells, but replicated with delayed kinetics in human MT-4 cells. These findings may be useful for establishing a murine model for HIV-1 replication. 相似文献
42.
43.
Determinants in the pathways followed by the carbons of acetone in their conversion to glucose 总被引:1,自引:0,他引:1
K Kosugi V Chandramouli K Kumaran W C Schumann B R Landau 《The Journal of biological chemistry》1986,261(28):13179-13181
[2-14C]Acetone was infused into rats that were fed or fasted. Each was infused with either a trace quantity of acetone or a large quantity that resulted in a blood concentration of acetone of at least 4 mM. The distribution of 14C in the carbons of glucose from each rat was determined. Two of the rats were given acetone in their drinking water and one was diabetic. Whether a rat was chronically exposed to acetone, fed or fasted, normal or diabetic, if given the trace dose, over 80% of the 14C in the glucose it formed was in carbons 1, 2, 5, and 6 of the glucose. If a rat was given the large dose, about 50% was in carbons 3 and 4. Thus, the major determinant of the pathways followed by acetone when it is metabolized is its concentration and not the prior dietary state of the animal or its previous exposure to acetone. Incorporation into carbons 1, 2, 5, and 6 occurs in the conversion of the carbons of [2-14C]lactate into glucose, whereas incorporation into carbons 3 and 4 occurs in the conversion of the carbons of [1-14C]acetate into glucose. Therefore, at high acetone concentration, the pathway that has been proposed for acetone's metabolism via acetate predominates, and via acetate there can be no net synthesis of glucose from acetone. When rats were given cyanamide and then the large dose of acetone, 74% of the 14C in the glucose they formed was in carbons 3 and 4 of the glucoses. Thus, the relative contribution of the pathway to lactate, or its metabolic equivalent, that has been proposed appears to be lessened by the administration of an aldehyde dehydrogenase inhibitor. 相似文献
44.
CONTRIBUTION OF THE PENTOSE CYCLE TO THE METABOLISM OF GLUCOSE IN THE ISOLATED, PERFUSED BRAIN OF THE MONKEY 总被引:3,自引:2,他引:1
K. Y. Hostetler B. R. Landau R. J. White M. S. Albin D. Yashon 《Journal of neurochemistry》1970,17(1):33-39
Abstract— Isolated brains from three adult monkeys were perfused for 1 hr with [2-14 C]glucose. Glycogen was isolated from the brain stem, cerebral hemispheres, cerebellum and the hypothalamic area at completion of the perfusions. The distribution of 14 C in carbons of the glucose unit of glycogen was determined and from this the contribution of the pentose cycle to metabolism of glucose was calculated. The data indicate a maximum contribution by the pentose cycle of 5–8 per cent in brain. No significant difference was observed in the various portions of brain. Oxygen consumption was noted to be low in relation to the amount of glucose utilized, as measured in these experiments. 相似文献
45.
Human colostral whey M-1 glycoproteins and their L. bifidus var. Penn. growth promoting activities 总被引:1,自引:0,他引:1
W Landau 《Life sciences》1974,14(5):967-976
A total of seven M-1 glycoprotein fractions were isolated from human colostrum whey and all showed L. bifidus var. Penn. growth promoting activities using well defined chemical medium. The growth promoting activity of these fractions was parallel to their total carbohydrate content. On the other hand, bovine colostrum M-1 glycoprotein had a relatively low growth promoting activity, whereas human serum orosomucoid had none. 相似文献
46.
47.
48.
49.
Antifungal activity of micelial fungus metabolites (of genera Aspergillus, Penicillium, Fusarium, Stachybotris, Cladosporium, Alternaria, Gliocladium, Paecilomyces, Trichoderma etc.) was determined. It was shown that antifungal activity of some micromycetes is due to the formation of substances inhibiting sterols biosynthesis in eucaryote cells. Inhibitors of enzymes of sterols biosynthesis were isolated and their activity was investigated. It was shown, that isolated fungus inhibitors of sterols biosynthesis inhibited the growth of test-organism Rhodotorula rubra and decreased ergosterin level in yeast cells. The qualitative content of yeast cell sterols was not changed in the presence of fungus inhibitors. 相似文献
50.
Permutations on strings representing gene clusters on genomes have been studied earlier by Uno and Yagiura (2000), Heber and Stoye (2001), Bergeron et al. (2002), Eres et al. (2003), and Schmidt and Stoye (2004) and the idea of a maximal permutation pattern was introduced by Eres et al. (2003). In this paper, we present a new tool for representation and detection of gene clusters in multiple genomes, using PQ trees (Booth and Leuker, 1976): this describes the inner structure and the relations between clusters succinctly, aids in filtering meaningful from apparently meaningless clusters, and also gives a natural and meaningful way of visualizing complex clusters. We identify a minimal consensus PQ tree and prove that it is equivalent to a maximal pi pattern (Eres et al., 2003) and each subgraph of the PQ tree corresponds to a nonmaximal permutation pattern. We present a general scheme to handle multiplicity in permutations and also give a linear time algorithm to construct the minimal consensus PQ tree. Further, we demonstrate the results on whole genome datasets. In our analysis of the whole genomes of human and rat, we found about 1.5 million common gene clusters but only about 500 minimal consensus PQ trees, with E. Coli K-12 and B. Subtilis genomes, we found only about 450 minimal consensus PQ trees out of about 15,000 gene clusters, and when comparing eight different Chloroplast genomes, we found only 77 minimal consensus PQ trees out of about 6,700 gene clusters. Further, we show specific instances of functionally related genes in two of the cases. 相似文献