全文获取类型
收费全文 | 136篇 |
免费 | 9篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 9篇 |
2020年 | 1篇 |
2019年 | 6篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 9篇 |
2013年 | 16篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 5篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 11篇 |
2006年 | 2篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1989年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有145条查询结果,搜索用时 375 毫秒
41.
Regulatory roles for small RNAs in bacteria 总被引:1,自引:0,他引:1
42.
Toxoplasma gondii autophagy‐related protein ATG9 is crucial for the survival of parasites in their host 下载免费PDF全文
Rana El Hajj Nadim Tawil Laurence Berry Maryse Lebrun Yann Bordat Sébastien Besteiro 《Cellular microbiology》2017,19(6)
Autophagy is a conserved, life‐promoting, catabolic process involved in the recycling of nonessential cellular components in response to stress. The parasite Toxoplasma gondii is an early‐diverging eukaryote in which part of the autophagy machinery is not exclusively involved in a catabolic process but instead has been repurposed for an original function in organelle inheritance during cell division. This function, depending essentially on protein TgATG8 and its membrane conjugation system, is crucial for parasite survival and prevented an in depth study of autophagy in the mutants generated so far in Toxoplasma. Thus, in order to decipher the primary function of canonical autophagy in the parasites, we generated a cell line deficient for TgATG9, a protein thought to be involved in the early steps of the autophagy process. Although the protein proved to be dispensable for the development of these obligate intracellular parasites in vitro, the absence of TgATG9 led to a reduced ability to sustain prolonged extracellular stress. Importantly, depletion of the protein significantly reduced parasites survival in macrophages and markedly attenuated their virulence in mice. Altogether, this shows TgATG9 is important for the fate of Toxoplasma in immune cells and contributes to the overall virulence of the parasite, possibly through an involvement in a canonical autophagy pathway. 相似文献
43.
Nadim Ballout Lola Etievant Vivian Viallon 《Biometrical journal. Biometrische Zeitschrift》2023,65(5):2200047
Cross-validation is the standard method for hyperparameter tuning, or calibration, of machine learning algorithms. The adaptive lasso is a popular class of penalized approaches based on weighted L1-norm penalties, with weights derived from an initial estimate of the model parameter. Although it violates the paramount principle of cross-validation, according to which no information from the hold-out test set should be used when constructing the model on the training set, a “naive” cross-validation scheme is often implemented for the calibration of the adaptive lasso. The unsuitability of this naive cross-validation scheme in this context has not been well documented in the literature. In this work, we recall why the naive scheme is theoretically unsuitable and how proper cross-validation should be implemented in this particular context. Using both synthetic and real-world examples and considering several versions of the adaptive lasso, we illustrate the flaws of the naive scheme in practice. In particular, we show that it can lead to the selection of adaptive lasso estimates that perform substantially worse than those selected via a proper scheme in terms of both support recovery and prediction error. In other words, our results show that the theoretical unsuitability of the naive scheme translates into suboptimality in practice, and call for abandoning it. 相似文献
44.
Nadim W Alkharouf Anik L Dhanaraj Dhananjay Naik Chris Overall Benjamin F Matthews Lisa J Rowland 《BMC plant biology》2007,7(1):5
Background
Blueberry is a member of the Ericaceae family, which also includes closely related cranberry and more distantly related rhododendron, azalea, and mountain laurel. Blueberry is a major berry crop in the United States, and one that has great nutritional and economical value. Extreme low temperatures, however, reduce crop yield and cause major losses to US farmers. A better understanding of the genes and biochemical pathways that are up- or down-regulated during cold acclimation is needed to produce blueberry cultivars with enhanced cold hardiness. To that end, the blueberry genomics database (BBDG) was developed. Along with the analysis tools and web-based query interfaces, the database serves both the broader Ericaceae research community and the blueberry research community specifically by making available ESTs and gene expression data in searchable formats and in elucidating the underlying mechanisms of cold acclimation and freeze tolerance in blueberry. 相似文献45.
Savithiry Natarajan Mona Tavakolan Nadim W Alkharouf Benjamin F Matthews 《Bioinformation》2014,10(6):387-389
Soybean cyst nematode (Heterodera glycines, SCN) is the most destructive pathogen of soybean around the world. Crop rotation and
resistant cultivars are used to mitigate the damage of SCN, but these approaches are not completely successful because of the
varied SCN populations. Thus, the limitations of these practices with soybean dictate investigation of other avenues of protection
of soybean against SCN, perhaps through genetically engineering of broad resistance to SCN. For better understanding of the
consequences of genetic manipulation, elucidation of SCN protein composition at the subunit level is necessary. We have
conducted studies to determine the composition of SCN proteins using a proteomics approach in our laboratory using twodimensional
polyacrylamide gel electrophoresis (2D-PAGE) to separate SCN proteins and to characterize the proteins further using
mass spectrometry. Our analysis resulted in the identification of several hundred proteins. In this investigation, we developed a
web based database (SCNProDB) containing protein information obtained from our previous published studies. This database will
be useful to scientists who wish to develop SCN resistant soybean varieties through genetic manipulation and breeding efforts.
The database is freely accessible from:
http://bioinformatics.towson.edu/Soybean_SCN_proteins_2D_Gel_DB/Gel1.aspx 相似文献
46.
47.
The role of short-term synaptic dynamics in motor control 总被引:5,自引:0,他引:5
During the past few years, much attention has been given to the role of short-term synaptic plasticity, in particular depression and facilitation, in sculpting network activity. A recent study shows that synaptic depression in rhythmic motor networks could switch the control of network frequency from intrinsic neuronal properties to the synaptic dynamics. Short-term synaptic plasticity is also involved in the stabilization and reconfiguration of motor circuits and in the initiation, maintenance and modulation of motor programs. 相似文献
48.
Vincent P. Klink Parsa Hosseini Prachi Matsye Nadim W. Alkharouf Benjamin F. Matthews 《Plant molecular biology》2009,71(6):525-567
The syncytium is a nurse cell formed within the roots of Glycine max by the plant parasitic nematode Heterodera glycines. Its development and maintenance are essential for nematode survival. The syncytium appears to undergo two developmental phases during its maturation into a functional nurse cell. The first phase is a parasitism phase where the nematode establishes the molecular circuitry that during the second phase ensures a compatible interaction with the plant cell. The cytological features of syncytia undergoing susceptible or resistant reactions appear the same during the parasitism phase. Depending on the outcome of any defense response, the second phase is a period of syncytium maintenance (susceptible reaction) or failure (resistant reaction). In the analyses presented here, the localized gene expression occurring at the syncytium during the resistant reaction was studied. This was accomplished by isolating syncytial cells from Glycine max genotype Peking (PI 548402) by laser capture microdissection. Microarray analyses using the Affymetrix® soybean GeneChip® directly compared Peking syncytia undergoing a resistant reaction to those undergoing a susceptible reaction during the parasitism phase of the resistant reaction. Those analyses revealed lipoxygenase-9 and lipoxygenase-4 as the most highly induced genes in the resistant reaction. The analysis also identified induced levels of components of the phenylpropanoid pathway. These genes included phenylalanine ammonia lyase, chalcone isomerase, isoflavone reductase, cinnamoyl-CoA reductase and caffeic acid O-methyltransferase. The presence of induced levels of these genes implies the importance of jasmonic acid and phenylpropanoid signaling pathways locally at the site of the syncytium during the resistance phase of the resistant reaction. The analysis also identified highly induced levels of four S-adenosylmethionine synthetase genes, the EARLY-RESPONSIVE TO DEHYDRATION 2 gene and the 14-3-3 gene known as GENERAL REGULATORY FACTOR 2. Subsequent analyses studied microdissected syncytial cells at 3, 6 and 9 days post infection (dpi) during the course of the resistant reaction, resulting in the identification of signature gene expression profiles at each time point in a single G. max genotype, Peking. 相似文献
49.
How do species barriers decay? Concordance and local introgression in mosaic hybrid zones of mussels
Alexis Simon Christelle Fraïsse Tahani El Ayari Cathy Liautard‐Haag Petr Strelkov John J. Welch Nicolas Bierne 《Journal of evolutionary biology》2021,34(1):208-223
The Mytilus complex of marine mussel species forms a mosaic of hybrid zones, found across temperate regions of the globe. This allows us to study ‘replicated’ instances of secondary contact between closely related species. Previous work on this complex has shown that local introgression is both widespread and highly heterogeneous, and has identified SNPs that are outliers of differentiation between lineages. Here, we developed an ancestry‐informative panel of such SNPs. We then compared their frequencies in newly sampled populations, including samples from within the hybrid zones, and parental populations at different distances from the contact. Results show that close to the hybrid zones, some outlier loci are near to fixation for the heterospecific allele, suggesting enhanced local introgression, or the local sweep of a shared ancestral allele. Conversely, genomic cline analyses, treating local parental populations as the reference, reveal a globally high concordance among loci, albeit with a few signals of asymmetric introgression. Enhanced local introgression at specific loci is consistent with the early transfer of adaptive variants after contact, possibly including asymmetric bi‐stable variants (Dobzhansky‐Muller incompatibilities), or haplotypes loaded with fewer deleterious mutations. Having escaped one barrier, however, these variants can be trapped or delayed at the next barrier, confining the introgression locally. These results shed light on the decay of species barriers during phases of contact. 相似文献
50.
Mylène Vincent Erwann Philippe Amandine Everard Nadim Kassis Claude Rouch Jessica Denom Yorihiko Takeda Shoji Uchiyama Nathalie M. Delzenne Patrice D. Cani Stéphanie Migrenne Christophe Magnan 《Obesity (Silver Spring, Md.)》2013,21(3):553-561