全文获取类型
收费全文 | 678篇 |
免费 | 128篇 |
专业分类
806篇 |
出版年
2015年 | 13篇 |
2014年 | 12篇 |
2013年 | 13篇 |
2012年 | 13篇 |
2011年 | 18篇 |
2010年 | 14篇 |
2009年 | 16篇 |
2008年 | 17篇 |
2007年 | 14篇 |
2006年 | 20篇 |
2005年 | 18篇 |
2004年 | 18篇 |
2003年 | 25篇 |
2002年 | 18篇 |
2001年 | 19篇 |
2000年 | 24篇 |
1999年 | 23篇 |
1998年 | 11篇 |
1997年 | 7篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1992年 | 11篇 |
1991年 | 12篇 |
1990年 | 15篇 |
1989年 | 10篇 |
1988年 | 17篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 14篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 15篇 |
1978年 | 22篇 |
1977年 | 11篇 |
1976年 | 14篇 |
1975年 | 24篇 |
1974年 | 21篇 |
1973年 | 10篇 |
1972年 | 24篇 |
1971年 | 15篇 |
1970年 | 11篇 |
1969年 | 13篇 |
1968年 | 8篇 |
1967年 | 9篇 |
1966年 | 7篇 |
1965年 | 6篇 |
1957年 | 6篇 |
排序方式: 共有806条查询结果,搜索用时 15 毫秒
1.
J.T. Bonner 《FEMS microbiology letters》1994,120(1-2):1-7
Abstract Glycoproteins are providing to be quite common in prokaryotes. Those is S-layers are the best understood in terms of structure. Numerous eubacteria produce non-S-layer glycoproteins about which relatively little is known. The glycans on such protein and the nature and sites of their linkages to protein are novel in those glycoproteins which have been examined in any detail. The possible functions of the glycans are mostly not understood. Eubacterial non-S-layer glycoproteins and the glycosylation systems producing them observe more attention. 相似文献
2.
3.
MOTIVATION: STS-content data for genomic mapping contain numerous errors and anomalies resulting in cross-links among distant regions of the genome. Identification of contigs within the data is an important and difficult problem. RESULTS: This paper introduces a graph algorithm which creates a simplified view of STS-content data. The shape of the resulting structure graph provides a quality check - coherent data produce a straight line, while anomalous data produce branches and loops. In the latter case, it is sometimes possible to disentangle the various paths into subsets of the data covering contiguous regions of the genome, i.e. contigs. These straight subgraphs can then be analyzed in standard ways to construct a physical map. A theoretical basis for the method is presented along with examples of its application to current STS data from human genome centers. AVAILABILITY: Freely available on request. 相似文献
4.
Cytofluorometric analysis of anti-lymphocyte antibodies in AIDS 总被引:1,自引:0,他引:1
Abstract Anti-lymphocyte antibodies (ALA) have been detected in the plasma of 53.8% of HIV-positive patients tested (CD4/CD8 ratios: mean 0.265; range 0.01 to 0.5) using analytical continuous-flow cytofluorometry. IgG from the AIDS plasma was seen to bind to normal PBL in 53.8% of cases (14/26). In double labelling experiments CD4 + lymphocytes, CD8 + lymphocytes, and B lymphocytes were all bound by the ALA, but monocytes were not bound. Pre-adsorption of the diluted AIDS plasma onto an excess of mouse spleen cells did not remove lymphocyte binding activity. No evidence was found for preferential binding to phytohaemagglutinin-stimulated lymphocytes.
ALA could not be detected in the plasma of normal subjects, patients with acute renal failure undergoing renal dialysis, or patients with high levels of circulating immune complexes. 相似文献
ALA could not be detected in the plasma of normal subjects, patients with acute renal failure undergoing renal dialysis, or patients with high levels of circulating immune complexes. 相似文献
5.
6.
The complete coding sequence of the human raf oncogene and the corresponding structure of the c-raf-1 gene. 总被引:36,自引:4,他引:32 下载免费PDF全文
T I Bonner H Oppermann P Seeburg S B Kerby M A Gunnell A C Young U R Rapp 《Nucleic acids research》1986,14(2):1009-1015
The complete 648 amino acid sequence of the human raf oncogene was deduced from the 2977 nucleotide sequence of a fetal liver cDNA. The cDNA has been used to obtain clones which extend the human c-raf-1 locus by an additional 18.9 kb at the 5' end and contain all the remaining coding exons. 相似文献
7.
Specific Inhibition of the Cyanide-insensitive Respiratory Pathway in Plant Mitochondria by Hydroxamic Acids 总被引:77,自引:44,他引:33 下载免费PDF全文
Gregory R. Schonbaum Walter D. Bonner Jr. Bayard T. Storey James T. Bahr 《Plant physiology》1971,47(1):124-128
Hydroxamic acids, R-CONHOH, are inhibitors specific to the respiratory pathway through the alternate, cyanide-insensitive terminal oxidase of plant mitochondria. The nature of the R group in these compounds affects the concentration at which the hydroxamic acids are effective, but it appears that all hydroxamic acids inhibit if high enough concentrations are used. The benzhydroxamic acids are effective at relatively low concentrations; of these, the most effective are m-chlorobenzhydroxamic acid and m-iodobenzhydroxamic acid. The concentrations required for half-maximal inhibition of the alternate oxidase pathway in mung bean (Phaseolus aureus) mitochondria are 0.03 mm for m-chlorobenzhydroxamic acid and 0.02 mm for m-iodobenzhydroxamic acid. With skunk cabbage (Symplocarpus foetidus) mitochondria, the required concentrations are 0.16 for m-chlorobenzhydroxamic acid and 0.05 for m-iodobenzhydroxamic acid. At concentrations which inhibit completely the alternate oxidase pathway, these two compounds have no discernible effect on either the respiratory pathway through cytochrome oxidase, or on the energy coupling reactions of these mitochondria. These inhibitors make it possible to isolate the two respiratory pathways and study their mode of action separately. These inhibitors also enhance an electron paramagnetic resonance signal near g = 2 in anaerobic, submitochondrial particles from skunk cabbage, which appears to be specific to the alternate oxidase and thus provides a means for its assay. 相似文献
8.
9.
Grey seals on the West Hoyle Bank feed on a variety of fish and have a high incidence of dermal lesions, often associated with emaciation and nematode parasite infection. Corynebacterium phocae has been isolated from an active lesion. The significance of large numbers of seals in the Dee Estuary bearing lesions is discussed and the occurrence of seals with lesions elsewhere in British waters is reviewed. No evidence was found to associate the dermal lesions with any environmental factor and it is probable that lesions develop as a result of infection of minor wounds. 相似文献
10.
Comparison of Undefined Medium and Its Dialyzable Fraction for Growth of Mycoplasma 总被引:11,自引:3,他引:8 下载免费PDF全文
In examining the medium used in cultivation of Mycoplasma for deoxyribonucleic acid isolation, it was found that an aggregate was present which sedimented with the organisms and which was ethyl alcohol-precipitated during deoxyribonucleic acid purification. To eliminate the contaminating material, a method was devised to obtain only the dialyzable constituents of the medium. This report describes the preparation of a dialysate of soy peptone-yeast extract. The medium, obtained by immersion of the encased dehydrated ingredients in sodium chloride solution for 5.5 hr at approximately 80 C, has been employed as the basal medium for cultivation of a number of Mycoplasma species. Comparative growth curves of two saprophytic strains and two parasitic species indicated that multiplication in dialysate, with suitable supplement, followed the pattern typical of the common eubacteria. Thus, by elimination of the sediment which occurred in nondialyzed medium, Mycoplasma could be concentrated without concomitant accumulation of contaminating macromolecules. 相似文献