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排序方式: 共有875条查询结果,搜索用时 93 毫秒
71.
Baart GJ Zomer B de Haan A van der Pol LA Beuvery EC Tramper J Martens DE 《Genome biology》2007,8(7):R136
Background
Neisseria meningitidis is a human pathogen that can infect diverse sites within the human host. The major diseases caused by N. meningitidis are responsible for death and disability, especially in young infants. In general, most of the recent work on N. meningitidis focuses on potential antigens and their functions, immunogenicity, and pathogenicity mechanisms. Very little work has been carried out on Neisseria primary metabolism over the past 25 years. 相似文献72.
73.
74.
Simon J. Watson Pinky Langat Scott M. Reid Tommy Tsan-Yuk Lam Matthew Cotten Michael Kelly Kristien Van Reeth Yu Qiu Ga?lle Simon Emilie Bonin Emanuela Foni Chiara Chiapponi Lars Larsen Charlotte Hjulsager Iwona Markowska-Daniel Kinga Urbaniak Ralf Dürrwald Michael Schlegel Anita Huovilainen Irit Davidson ádám Dán Willie Loeffen Stephanie Edwards Michel Bublot Thais Vila Jaime Maldonado Laura Valls ESNIP Consortium Ian H. Brown Oliver G. Pybus Paul Kellam 《Journal of virology》2015,89(19):9920-9931
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76.
Silvas J Prince Li Song Dan Qiu Joao V Maldonado dos Santos Chenglin Chai Trupti Joshi Gunvant Patil Babu Valliyodan Tri D Vuong Mackensie Murphy Konstantinos Krampis Dominic M Tucker Ruslan Biyashev Anne E Dorrance MA Saghai Maroof Dong Xu J Grover Shannon Henry T Nguyen 《BMC genomics》2015,16(1)
Background
Root system architecture is important for water acquisition and nutrient acquisition for all crops. In soybean breeding programs, wild soybean alleles have been used successfully to enhance yield and seed composition traits, but have never been investigated to improve root system architecture. Therefore, in this study, high-density single-feature polymorphic markers and simple sequence repeats were used to map quantitative trait loci (QTLs) governing root system architecture in an inter-specific soybean mapping population developed from a cross between Glycine max and Glycine soja.Results
Wild and cultivated soybean both contributed alleles towards significant additive large effect QTLs on chromosome 6 and 7 for a longer total root length and root distribution, respectively. Epistatic effect QTLs were also identified for taproot length, average diameter, and root distribution. These root traits will influence the water and nutrient uptake in soybean. Two cell division-related genes (D type cyclin and auxin efflux carrier protein) with insertion/deletion variations might contribute to the shorter root phenotypes observed in G. soja compared with cultivated soybean. Based on the location of the QTLs and sequence information from a second G. soja accession, three genes (slow anion channel associated 1 like, Auxin responsive NEDD8-activating complex and peroxidase), each with a non-synonymous single nucleotide polymorphism mutation were identified, which may also contribute to changes in root architecture in the cultivated soybean. In addition, Apoptosis inhibitor 5-like on chromosome 7 and slow anion channel associated 1-like on chromosome 15 had epistatic interactions for taproot length QTLs in soybean.Conclusion
Rare alleles from a G. soja accession are expected to enhance our understanding of the genetic components involved in root architecture traits, and could be combined to improve root system and drought adaptation in soybean.Electronic supplementary material
The online version of this article (doi:10.1186/s12864-015-1334-6) contains supplementary material, which is available to authorized users. 相似文献77.
Eoghan M Cunnane John JE Mulvihill Hilary E Barrett Michael T Walsh 《Biomedical engineering online》2015,14(Z1):S7
Background
Due to the limited number of experimental studies that mechanically characterise human atherosclerotic plaque tissue from the femoral arteries, a recent trend has emerged in current literature whereby one set of material data based on aortic plaque tissue is employed to numerically represent diseased femoral artery tissue. This study aims to generate novel vessel-appropriate material models for femoral plaque tissue and assess the influence of using material models based on experimental data generated from aortic plaque testing to represent diseased femoral arterial tissue.Methods
Novel material models based on experimental data generated from testing of atherosclerotic femoral artery tissue are developed and a computational analysis of the revascularisation of a quarter model idealised diseased femoral artery from a 90% diameter stenosis to a 10% diameter stenosis is performed using these novel material models. The simulation is also performed using material models based on experimental data obtained from aortic plaque testing in order to examine the effect of employing vessel appropriate material models versus those currently employed in literature to represent femoral plaque tissue.Results
Simulations that employ material models based on atherosclerotic aortic tissue exhibit much higher maximum principal stresses within the plaque than simulations that employ material models based on atherosclerotic femoral tissue. Specifically, employing a material model based on calcified aortic tissue, instead of one based on heavily calcified femoral tissue, to represent diseased femoral arterial vessels results in a 487 fold increase in maximum principal stress within the plaque at a depth of 0.8 mm from the lumen.Conclusions
Large differences are induced on numerical results as a consequence of employing material models based on aortic plaque, in place of material models based on femoral plaque, to represent a diseased femoral vessel. Due to these large discrepancies, future studies should seek to employ vessel-appropriate material models to simulate the response of diseased femoral tissue in order to obtain the most accurate numerical results.78.
Background
Representation of independent biophysical sources using Fourier analysis can be inefficient because the basis is sinusoidal and general. When complex fractionated atrial electrograms (CFAE) are acquired during atrial fibrillation (AF), the electrogram morphology depends on the mix of distinct nonsinusoidal generators. Identification of these generators using efficient methods of representation and comparison would be useful for targeting catheter ablation sites to prevent arrhythmia reinduction.Method
A data-driven basis and transform is described which utilizes the ensemble average of signal segments to identify and distinguish CFAE morphologic components and frequencies. Calculation of the dominant frequency (DF) of actual CFAE, and identification of simulated independent generator frequencies and morphologies embedded in CFAE, is done using a total of 216 recordings from 10 paroxysmal and 10 persistent AF patients. The transform is tested versus Fourier analysis to detect spectral components in the presence of phase noise and interference. Correspondence is shown between ensemble basis vectors of highest power and corresponding synthetic drivers embedded in CFAE.Results
The ensemble basis is orthogonal, and efficient for representation of CFAE components as compared with Fourier analysis (p ≤ 0.002). When three synthetic drivers with additive phase noise and interference were decomposed, the top three peaks in the ensemble power spectrum corresponded to the driver frequencies more closely as compared with top Fourier power spectrum peaks (p ≤ 0.005). The synthesized drivers with phase noise and interference were extractable from their corresponding ensemble basis with a mean error of less than 10%.Conclusions
The new transform is able to efficiently identify CFAE features using DF calculation and by discerning morphologic differences. Unlike the Fourier transform method, it does not distort CFAE signals prior to analysis, and is relatively robust to jitter in periodic events. Thus the ensemble method can provide a useful alternative for quantitative characterization of CFAE during clinical study. 相似文献79.
Maldonado B Buchanan G Müller M Berks BC Palmer T 《Journal of molecular microbiology and biotechnology》2011,20(3):168-175
The twin arginine protein transport (Tat) system transports folded proteins across the cytoplasmic membranes of prokaryotes and the thylakoid membranes of plant chloroplasts. In Escherichia coli, the TatB and TatC components form a multivalent receptor complex that binds Tat substrates. Here, we have used a genetic fusion approach to construct covalent TatC oligomers in order to probe the organisation of TatC. A fused dimer of TatC supported Tat transport activity and was fully stable in vivo. Inactivating point mutations in one or other of the TatC units in the fused TatC dimer did not inactivate TatC function, indicating that only one TatC protomer in the TatC fused dimer needs to be active. Larger covalent fusions of TatC also supported Tat transport activity but were degraded in vivo to release smaller TatC forms. Taken together, these results strongly suggest that TatC forms a functional dimer, and support the idea that there is an even number of TatC protomers in the TatBC complex. 相似文献
80.
Maldonado GE Pérez CA Covarrubias EE Cabriales SA Leyva LA Pérez JC Almaguer DG 《Cytotherapy》2011,13(10):1249-1255
BACKGROUND AIMS. Lymphedema is a common complication with breast cancer treatment that does not have a definite cure. Our objective was to determine the efficacy of autologous stem cells (ASC) in the treatment of lymphedema secondary to mastectomy and axillary lymphadenectomy in comparison with traditional decongestive treatment with compression sleeves. METHODS. A prospective study including 20 women with lymphedema secondary to breast cancer surgery with axillary lymphadenectomy was conducted. Women were assigned at random to one of two groups. One group of 10 women was injected with ASC in the affected arm, whereas the other 10 women comprised the control group and received traditional compression sleeve therapy (CST). The follow-up for both groups was 12 weeks. Pain, sensitivity and mobility were assessed before and after therapy. RESULTS. There was improvement in the volume of lymphedema in both groups, with no significant difference. In the ASC group there was an overall volume reduction during the follow-up, whereas in the CST group lymphedema recurred after the compression sleeve was removed. CONCLUSIONS. Our findings suggest that ASC injection for patients with lymphedema can be an effective treatment. It reduces arm volume and associated co-morbidities of pain and decreased sensitivity. Traditional CST was also effective for lymphedema reduction, but it was dependent on continuous use of the treatment. 相似文献