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排序方式: 共有322条查询结果,搜索用时 15 毫秒
251.
Felipe Sérgio Heitor Sousa Batista Diego Silva Chagas Kristhiano Correia Ludmila Nayara Freitas Silva Tatiane Dulcineia Fortini Evandro Alexandre Silva Priscila Oliveira Otoni Wagner Campos 《Protoplasma》2019,256(6):1557-1571
Protoplasma - Ultraviolet-B (UV-B) radiation is an elicitor of secondary metabolites in plant tissue culture, but the effects on 20-hydroxyecdysone (20E) are still unclear. The 20E may show... 相似文献
252.
Given their large movement capacities, migratory birds have in principle a wide range of possible geographical locations for their breeding and non‐breeding destinations, yet each species migrates between consistent breeding and non‐breeding ranges. In this study, we use a macroecological approach to search for the general factors explaining the location of the seasonal ranges of migratory bird species across the globe. We develop a null model to test the hypotheses that access to resources, geographical distance, tracking of temperature, and habitat conditions (separately as well as considered together) have a major influence in the location of species’ migratory destinations, once each species’ geographical constraints are taken into account. Our results provide evidence for a trade‐off between costs associated with distance travelled and gains in terms of better access to resources. We also provide strong support to the hypotheses that all factors tested, with the exception of habitat, have a strong and additive effect on the global geography of bird migration. Indeed, our results indicate that species’ contemporary migratory destinations (i.e. the combination of their breeding and non‐breeding ranges) are such that they allow species to track a temperature regime throughout the year, to escape local competition and reach areas with better access to resources, and to minimise the spatial distance travelled, within the limitations imposed by the geographical location of each species. Our study thus sheds light on the mechanisms underpinning bird migration and provides a strong basis for predicting how migratory species will respond to future change. 相似文献
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Gabriel S. Vignoli Muniz Lilia I. De la Torre Evandro L. Duarte Esteban N. Lorenzón Eduardo M. Cilli Andrea Balan M. Teresa Lamy 《Biochemistry and Biophysics Reports》2020
Antimicrobial peptides (AMPs) have been appointed as a possible alternative to traditional antibiotics in face of pathogens increasing resistance to conventional drugs. Hylin a1 (IFGAILPLALGALKNLIK), an AMP extracted from the skin secretion of a South American frog, Hypsiboas albopunctatus, was found to show a strong cytotoxicity against bacteria and fungus, but also a considerable hemolytic action. Considering the toxicity of the peptide in eukaryotic cells, this work focuses on investigating the effects of the interaction of the Hylin a1 analogues W6Hya1, D0W6Hya1 and K0W6Hya1 with models of eukaryotic structures, namely zwitterionic liposomes of dipalmitoyl phosphatidylcholine (DPPC) and calf-thymus DNA (CT DNA). Through intrinsic Trp fluorescence we determined that the peptide affinity for fluid DPPC bilayers follows the decreasing order: D0W6Hya1 (+2) > W6Hya1 (+3) » K0W6Hya1 (+4). Fluorescence data also indicate that the Trp residue in the more positively charged peptide, K0W6Hya1, is less deep in the bilayer than the residue in the other two peptides. This finding is supported by differential scanning calorimetry (DSC) data, which shows that both D0W6Hya1 and W6Hya1 disturb DPPC gel-fluid transition slightly more effectively than K0W6Hya1. DPPC DSC profiles are homogeneously disturbed by the three peptides, probably related to peptide-membrane diffusion. Surprisingly, the peptide that displays the lowest affinity for PC membranes and is located at the more superficial position in the bilayer, K0W6Hya1, is the most efficient in causing formation of pores on the membrane, as attested by carboxyfluorescein leakage assays. The three peptides were found to interact with CT DNA, with a deep penetration of the Trp residue into hydrophobic pockets of the double helix, as indicated by the significant blue shift on the Trp fluorescence, and the displacement of DNA-bound ethidium bromide by the peptides. The experiments of DNA electrophoresis confirm that Hylin peptides bind DNA in a concentration-dependent manner, inducing complete DNA retardation at the relative AMP/plasmid DNA weight ratio of ~17. These findings could help to better understand the AMPs toxic effects on eukaryotic cells, thus contributing to the design of healthier therapeutic agents. 相似文献
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Jhuly W. F. Lacerda Katia A. Siqueira Leonardo G. Vasconcelos Barbara S. Bellete Evandro L. Dall'Oglio Paulo T. Sousa Junior Tomer M. Faraggi Lucas C. C. Vieira Marcos A. Soares Olívia M. Sampaio 《化学与生物多样性》2021,18(10):e2100350
Endophytic fungi are an important class of microorganisms, able to interact with a host plant via a mutualistic mechanism without visible symptoms of the fungal colonization. The synergy between endophytic fungi and their host plant can promote morphological, physiological and biochemical changes through the expression of bioactive metabolites. This work aims to correlate metabolic changes in the Combretum lanceolatum plant metabolome with its endophytic fungi Diaporthe phaseolorum (Dp) and Trichoderma spirale (Ts), and to discover corresponding metabolite-biomarkers, with the principal focus being on its primary metabolism. The 1H-NMR metabolomic analysis of qualitative and quantitative changes was performed through multivariate statistical analysis and the identification of primary metabolites was achieved on the Madison Metabolomics Consortium Database. The presence of Dp significantly impacted the plant's metabolic pathways, improving the biosynthesis of primary metabolites such as threonine, malic acid and N-acetyl-mannosamine, which are precursors of special metabolites involved in plant self-defence. This work represents a valuable contribution to advanced studies on the metabolic profiles of the interaction of plants with endophytes. 相似文献
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Carla Botelho Machado Ana Paula Citadini Rosana Goldbeck Evandro Antônio de Lima Fernanda Lopes Figueiredo Tony Márcio da Silva Zaira Bruna Hoffmam Amanda Silva de Sousa Fábio Márcio Squina Maria de Lourdes Teixeira de Moraes Polizeli Roberto Ruller Richard John Ward 《Biotechnology letters》2015,37(7):1455-1462
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Peter Sykora Magdalena Misiak Yue Wang Somnath Ghosh Giovana S. Leandro Dong Liu Jane Tian Beverly A. Baptiste Wei-Na Cong Boris M. Brenerman Evandro Fang Kevin G. Becker Royce J. Hamilton Soumya Chigurupati Yongqing Zhang Josephine M. Egan Deborah L. Croteau David M. Wilson III Mark P. Mattson Vilhelm A. Bohr 《Nucleic acids research》2015,43(2):943-959
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The sperm of Hexagenia (Pseudeatonica) albivitta Walker (Ephemeroptera: Fossoriae: Ephemeridae) 下载免费PDF全文
Pedro Brito Karina Mancini Frederico Falcão Salles Evandro Apolinario Rizzi Heidi Dolder 《Acta zoologica》2015,96(2):160-166
This study describes the sperm morphology of the mayfly Hexagenia (Pseudeatonica) albivitta (Ephemeroptera). Its spermatozoon measures approximately 30 μm of which 9 μm corresponds to the head. The head is composed of an approximately round acrosomal vesicle and a cylindrical nucleus. The nucleus has two concavities, one in the anterior tip, where the acrosomal vesicle is inserted and a deeper one at its base, where the flagellum components are inserted. The flagellum is composed of an axoneme, a mitochondrion and a dense rod adjacent to the mitochondrion. A centriolar adjunct is also observed surrounding the axoneme in the initial portion of the flagellum and extends along the flagellum for at least 2 μm, surrounding the axoneme in a half‐moon shape. The axoneme is the longest component of the flagellum, and it follows the 9+9+0 pattern, with no central pair of microtubules. At the posterior region of the flagellum, the mitochondrion has a dumb‐bell shape in cross sections that, together with the rectangular mitochondrial‐associated rod, is responsible for the flattened shape of the flagellum. An internal membrane is observed surrounding both mitochondrion and its associated structure. 相似文献