全文获取类型
收费全文 | 100篇 |
免费 | 3篇 |
专业分类
103篇 |
出版年
2020年 | 1篇 |
2014年 | 4篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有103条查询结果,搜索用时 15 毫秒
1.
In studying the main indices that characterize the neurochemical system of biosynthesis and degradation of a dopamine neuromediator, tyrosine hydroxylase-dopamine-monoamine oxidase, in different brain regions 5-6 min, 1 and 18 h after whole-body irradiation with high energy electrons (100 Gy) the authors have revealed a 25-40% inhibition of tyrosine hydroxylase and monoamine oxidase activity, and a 40% increase in the dopamine content of basal ganglia of the brain that control behavioural reactions of the organism. The neurochemical disturbances revealed are involved in the mechanisms of early transient incapacity after irradiation with superhigh doses. 相似文献
2.
The administration to rats of Freund adjuvant and conditions of their keeping in the autumn time reduce the mass and cellularity of the thymus and inhibit cell proliferation therein, the content of lymphocytes with high buoyant density being relatively increased. The indicated changes are accompanied by a two-fold increase in the death rate of thymus cells both after irradiation of rats and following four-hour incubation. 相似文献
3.
No dependence was found between the index of the adenylic system phosphorylated state (ATP) : (ADP) (HPO2-4), the ratios (ATP) : (ADP) and (ATP : (ADP + AMP), on one hand, and the ratio (NAD+) : (NADH) in the cytoplasm, on the other one. The maximum value of the ratio (ATP) : (ADP) (HPO2-4) was observed on the 17th day of development and correlated with the maximum rate of gluconeogenesis. The ratio (NAD+) : (NADH) in the cytoplasm suffered no changes until hatching and decreased twice thereafter. 相似文献
4.
In July to August 1999–2001, 53 zooplankton species were recorded in high-mountain lakes of Altai (1800–2400 m above sea level). The abundance of zooplankton varies considerably, but the average values of abundance and biomass are low. According to zooplankton characteristics, the high-mountain lakes are oligotrophic and oligosaprobic. The species composition of the zooplankton community depends on the area and depth of the lakes, and the quantitative indices, particularly in the littoral zone, are determined by water temperature. 相似文献
5.
Two long repeats, MS3 and MS4, are predominantly located in sex-chromosomal heterochromatin in common vole species [1]. Their tandem arrangement was revealed by means of the PCR analysis of genomic DNAs of four Microtus species and by restriction mapping of clones selected from a M. rossiaemeridionalis genomic library. Several mobile elements proved to be incorporated in a monomeric unit of each repeat and amplified together with its other components. In addition, LINE inserts were found in MS4 tandem arrays. The copy number of both repeats per haploid genome was estimated at 100–300 for euchromatin and 20,000–40,000 for the M. rossiaemeridionalis genome. The repeats were assumed to be the major component of sex-chromosomal heterochromatin DNA. 相似文献
6.
B E Suzek M D Ermolaeva M Schreiber S L Salzberg 《Bioinformatics (Oxford, England)》2001,17(12):1123-1130
As the pace of genome sequencing has accelerated, the need for highly accurate gene prediction systems has grown. Computational systems for identifying genes in prokaryotic genomes have sensitivities of 98-99% or higher (Delcher et al., Nucleic Acids Res., 27, 4636-4641, 1999). These accuracy figures are calculated by comparing the locations of verified stop codons to the predictions. Determining the accuracy of start codon prediction is more problematic, however, due to the relatively small number of start sites that have been confirmed by independent, non-computational methods. Nonetheless, the accuracy of gene finders at predicting the exact gene boundaries at both the 5' and 3' ends of genes is of critical importance for microbial genome annotation, especially in light of the important signaling information that is sometimes found on the 5' end of a protein coding region. In this paper we propose a probabilistic method to improve the accuracy of gene identification systems at finding precise translation start sites. The new system, RBSfinder, is tested on a validated set of genes from Escherichia coli, for which it improves the accuracy of start site locations predicted by computational gene finding systems from the range 67-77% to 90% correct. 相似文献
7.
Deshevoĭ I Moroz BB Lyrshchikova AV Lebedev VG 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2002,42(4):384-389
In experiments on rats, disturbances in the development of blood system adaptive reactions on emotional stress were found. Under the combined effect of preliminary (before stress) exposure to 0.8 Gy of gamma-radiation and the emotional stress of various duration (2, 4 and 8 days), a compensatory capability of the blood system decreased. The degree of the disturbances directly depended on the duration of the emotional stress. 相似文献
8.
9.
Parallelism was noted between the suppression of proliferation and the amount of cells dying in mouse thymus after the effects inducing cell destruction. However, inhibition of DNA synthesis under the effect of nontoxic doses of arabinoside cytosine increased insignificantly the number of dying cells as compared to normal. This indicated the absence of the masking effect of reutilization of degradation products of dying cells, minor amounts of cells normally dying in the thymus, and their insignificant contribution to the induced cell death after the effects leading to inhibition of cell proliferation. 相似文献
10.