全文获取类型
收费全文 | 115篇 |
免费 | 12篇 |
出版年
2021年 | 1篇 |
2020年 | 2篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 3篇 |
2014年 | 11篇 |
2013年 | 5篇 |
2012年 | 6篇 |
2011年 | 5篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 1篇 |
1999年 | 1篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有127条查询结果,搜索用时 250 毫秒
61.
Grégory Jubelin Anne Lanois Dany Severac Stéphanie Rialle Cyrille Longin Sophie Gaudriault Alain Givaudan 《PLoS genetics》2013,9(10)
Heterogeneity in the expression of various bacterial genes has been shown to result in the presence of individuals with different phenotypes within clonal bacterial populations. The genes specifying motility and flagellar functions are coordinately regulated and form a complex regulon, the flagellar regulon. Complex interplay has recently been demonstrated in the regulation of flagellar and virulence gene expression in many bacterial pathogens. We show here that FliZ, a DNA-binding protein, plays a key role in the insect pathogen, Xenorhabdus nematophila, affecting not only hemolysin production and virulence in insects, but efficient swimming motility. RNA-Seq analysis identified FliZ as a global regulatory protein controlling the expression of 278 Xenorhabdus genes either directly or indirectly. FliZ is required for the efficient expression of all flagellar genes, probably through its positive feedback loop, which controls expression of the flhDC operon, the master regulator of the flagellar circuit. FliZ also up- or downregulates the expression of numerous genes encoding non-flagellar proteins potentially involved in key steps of the Xenorhabdus lifecycle. Single-cell analysis revealed the bimodal expression of six identified markers of the FliZ regulon during exponential growth of the bacterial population. In addition, a combination of fluorescence-activated cell sorting and RT-qPCR quantification showed that this bimodality generated a mixed population of cells either expressing (“ON state”) or not expressing (“OFF state”) FliZ-dependent genes. Moreover, studies of a bacterial population exposed to a graded series of FliZ concentrations showed that FliZ functioned as a rheostat, controlling the rate of transition between the “OFF” and “ON” states in individuals. FliZ thus plays a key role in cell fate decisions, by transiently creating individuals with different potentials for motility and host interactions. 相似文献
62.
Lodyga-Chruścińska E Ołdziej S Sochacka E Korzycka K Chruściński L Micera G Sanna D Turek M Pawlak J 《Journal of inorganic biochemistry》2011,105(9):1212-1219
Copper(II) complexes with a new chelator-type nucleoside-histidine modified 2′-deoxyriboadenosine (N-[(9-β-D-2′-deoxyribofuranosylpurin-6-yl)-carbamoyl]histidine) were studied by potentiometric and spectroscopic (UV-visible, CD, EPR) techniques, in conjunction with computer modeling optimization. The ligand can act as bidentate or tridentate depending on pH range. In acidic pH a very stable dimeric complex Cu2L2 predominates with coordination spheres of both metal ions composed of oxygen atoms from carboxylic groups, one oxygen atom from ureido group and two nitrogen atoms derived from purine base and histidine ring. Above pH 5, deprotonation of carbamoyl nitrogens leads to the formation of CuL2, Cu2L2H− 1 and Cu2L2H− 2 species. The CuL2H− 1 and CuL2H− 2 complexes with three or four nitrogens in Cu(II) coordination sphere have been detected in alkaline medium.Our findings suggest that N-[(9-beta-D-2′-deoxyribofuranosylpurin-6-yl)-carbamoyl]histidine chelates copper(II) ions very efficiently. The resulting complex might be used as an alternative base-pairing mode in which hydrogen-bonded base pairs present in natural DNA are replaced by metal-mediated ones. 相似文献
63.
Mattia CF Prosperi Luciano Prosperi Alessandro Bruselles Isabella Abbate Gabriella Rozera Donatella Vincenti Maria Carmela Solmone Maria Rosaria Capobianchi Giovanni Ulivi 《BMC bioinformatics》2011,12(1):5
Background
Next-generation sequencing (NGS) offers a unique opportunity for high-throughput genomics and has potential to replace Sanger sequencing in many fields, including de-novo sequencing, re-sequencing, meta-genomics, and characterisation of infectious pathogens, such as viral quasispecies. Although methodologies and software for whole genome assembly and genome variation analysis have been developed and refined for NGS data, reconstructing a viral quasispecies using NGS data remains a challenge. This application would be useful for analysing intra-host evolutionary pathways in relation to immune responses and antiretroviral therapy exposures. Here we introduce a set of formulae for the combinatorial analysis of a quasispecies, given a NGS re-sequencing experiment and an algorithm for quasispecies reconstruction. We require that sequenced fragments are aligned against a reference genome, and that the reference genome is partitioned into a set of sliding windows (amplicons). The reconstruction algorithm is based on combinations of multinomial distributions and is designed to minimise the reconstruction of false variants, called in-silico recombinants. 相似文献64.
The authors discussed disorders in adipocytokines' function in chronic renal failure (CRF) and their clinical implications. Adipocytokines' concentrations in CRF are in most cases elevated, which is associated with decreased level of their excretion. This may cause number of clinical implications such as inflammation, loss of appetite, development of protein energy wasting (PEW) syndrome and the progress of artherosclerosis, what leads to increased mortality in a group of patients with end-stage renal disease (ESRD). Disturbances in sexual hormones function are also characteristic for CRF. Disorders in fertility, sexual life and decreased quality of life are observed in patients with CRF. Therapeutic procedure is complicated and not fully effective. 相似文献
65.
Zhao Y Gowda M Liu W Würschum T Maurer HP Longin FH Ranc N Reif JC 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(4):769-776
Genomic selection is a promising breeding strategy for rapid improvement of complex traits. The objective of our study was
to investigate the prediction accuracy of genomic breeding values through cross validation. The study was based on experimental
data of six segregating populations from a half-diallel mating design with 788 testcross progenies from an elite maize breeding
program. The plants were intensively phenotyped in multi-location field trials and fingerprinted with 960 SNP markers. We
used random regression best linear unbiased prediction in combination with fivefold cross validation. The prediction accuracy
across populations was higher for grain moisture (0.90) than for grain yield (0.58). The accuracy of genomic selection realized
for grain yield corresponds to the precision of phenotyping at unreplicated field trials in 3–4 locations. As for maize up
to three generations are feasible per year, selection gain per unit time is high and, consequently, genomic selection holds
great promise for maize breeding programs. 相似文献
66.
Rampant horizontal transfer and duplication of rubisco genes in eubacteria and plastids 总被引:14,自引:2,他引:14
Previous work has shown that molecular phylogenies of plastids,
cyanobacteria, and proteobacteria based on the rubisco (ribulose-1,5-
bisphosphate carboxylase/oxygenase) genes rbcL and rbcS are incongruent
with molecular phylogenies based on other genes and are also incompatible
with structural and biochemical information. Although it has been much
speculated that this is the consequence of a single horizontal gene
transfer (of a proteobacterial or mitochondrial rubisco operon into
plastids of rhodophytic and chromophytic algae), neither this hypothesis
nor the alternative hypothesis of ancient gene duplication have been
examined in detail. We have conducted phylogenetic analyses of all
available bacterial rbcL sequences, and representative plastid sequences,
in order to explore these alternative hypothesis and fully examine the
complexity of rubisco gene evolution. The rbcL phylogeny reveals a
surprising number of gene relationships that are fundamentally incongruent
with organismal relationships as inferred from multiple lines of other
molecular evidence. On the order of six horizontal gene transfers are
implied by the form I (L8S8) rbcL phylogeny, two between cyanobacteria and
proteobacteria, one between proteobacteria and plastids, and three within
proteobacteria. Alternatively, a single ancient duplication of the form I
rubisco operon, followed by repeated and pervasive differential loss of one
operon or the other, would account for much of this incongruity. In all
probability, the rubisco operon has undergone multiple events of both
horizontal gene transfer and gene duplication in different lineages.
相似文献
67.
Richard A Stabler Lisa F Dawson Petra CF Oyston Richard W Titball Jim Wade Jason Hinds Adam A Witney Brendan W Wren 《BMC microbiology》2008,8(1):177
Background
Human and animal health is constantly under threat by emerging pathogens that have recently acquired genetic determinants that enhance their survival, transmissibility and virulence. We describe the construction and development of an Active Surveillance of Pathogens (ASP) oligonucleotide microarray, designed to 'actively survey' the genome of a given bacterial pathogen for virulence-associated genes. 相似文献68.
69.
M Gowda Y Zhao T Würschum C FH Longin T Miedaner E Ebmeyer R Schachschneider E Kazman J Schacht J-P Martinant M F Mette J C Reif 《Heredity》2014,112(5):552-561
The accuracy of genomic selection depends on the relatedness between the members of the
set in which marker effects are estimated based on evaluation data and the types for which
performance is predicted. Here, we investigate the impact of relatedness on the
performance of marker-assisted selection for fungal disease resistance in hybrid wheat. A
large and diverse mapping population of 1739 elite European winter wheat inbred lines and
hybrids was evaluated for powdery mildew, leaf rust and stripe rust resistance in
multi-location field trials and fingerprinted with 9 k and 90 k SNP arrays.
Comparison of the accuracies of prediction achieved with data sets from the two marker
arrays revealed a crucial role for a sufficiently high marker density in genome-wide
association mapping. Cross-validation studies using test sets with varying degrees of
relationship to the corresponding estimation sets revealed that close relatedness leads to
a substantial increase in the proportion of total genotypic variance explained by the
identified QTL and consequently to an overoptimistic judgment of the precision of
marker-assisted selection. 相似文献
70.
C. Friedrich H. Longin Xuefei Mi Albrecht E. Melchinger Jochen C. Reif Tobias Würschum 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(10):2117-2126