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排序方式: 共有1943条查询结果,搜索用时 375 毫秒
931.
Concepción De Linares Rosario Delgado Maria Jesús Aira Purificación Alcázar Silvia Alonso-Pérez Marzia Boi Paloma Cariñanos Emilio Cuevas Consuelo Díaz de la Guardia Belén Elvira-Rendueles Delia Fernández-González Carmen Galán Adela Montserrat Gutiérrez-Bustillo Rosa Pérez-Badia Francisco Javier Rodríguez-Rajo Luis Ruíz-Valenzuela Rafael Tormo-Molina Maria del Mar Trigo Rosa M. Valencia-Barrera Ana Valle Jordina Belmonte 《Aerobiologia》2017,33(3):375-391
In some areas, forests are being affected in diverse aspects such as structure, composition and biodiversity showing an increase or a decrease in the growth rates. Pinus is one of the most dominant genera in the forests of the Northern Hemisphere. This study analyzes the pine pollination patterns in 30 locations of Spain with an average of 21-year dataset. The aim is to evaluate possible changes in flowering intensity as well as in annual pollen production trends, according to the airborne pollen patterns. Annual Pollen Indices show three threshold values: (1) over 4000 grains per year in Catalonia, the Central System Mountains and Ourense (Galicia), (2) between 4000 and 1000 grains in central-south Spain and in the Balearic Islands, and (3) under 1000 in eastern Spain, Cartagena and the Canary Islands. Airborne pollen patterns were also influenced by Pinus species: The species located in the littoral and low land areas pollinated in the first pollination phase, from February to April, and the mountain pine species did in the second one, from April to June. The statistical analyses reveal increasing significant trends in 12 sites and significant decreasing trends in two. The Pinus flowering intensity is showing an earlier start and a delay in the end of the pollination period, thus a longer period of pollen in the air. This study suggests that the aerobiological monitoring is an interesting bio-indicator of changes happening in Pinus landscapes, and therefore explains the vulnerability of this genus in Spain. 相似文献
932.
Disrupting a key hydrophobic pair in the oligomerization interface of the actinoporins impairs their pore‐forming activity
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Haydeé Mesa‐Galloso Karelia H. Delgado‐Magnero Sheila Cabezas Aracelys López‐Castilla Jorge E. Hernández‐González Lohans Pedrera Carlos Alvarez D. Peter Tieleman Ana J. García‐Sáez Maria E. Lanio Uris Ros Pedro A. Valiente 《Protein science : a publication of the Protein Society》2017,26(3):550-565
Crystallographic data of the dimeric and octameric forms of fragaceatoxin C (FraC) suggested the key role of a small hydrophobic protein–protein interaction surface for actinoporins oligomerization and pore formation in membranes. However, site‐directed mutagenesis studies supporting this hypothesis for others actinoporins are still lacking. Here, we demonstrate that disrupting the key hydrophobic interaction between V60 and F163 (FraC numbering scheme) in the oligomerization interface of FraC, equinatoxin II (EqtII), and sticholysin II (StII) impairs the pore formation activity of these proteins. Our results allow for the extension of the importance of FraC protein–protein interactions in the stabilization of the oligomeric intermediates of StII and EqtII pointing out that all of these proteins follow a similar pathway of membrane disruption. These findings support the hybrid pore proposal as the universal model of actinoporins pore formation. Moreover, we reinforce the relevance of dimer formation, which appears to be a functional intermediate in the assembly pathway of some different pore‐forming proteins. 相似文献
933.
Martinelli Livia Zalar Polona Gunde-Cimerman Nina Azua-Bustos Armando Sterflinger Katja Piñar Guadalupe 《Extremophiles : life under extreme conditions》2017,21(4):755-773
Extremophiles - Halophilic fungal strains isolated from historical wooden staircase in a salt mine in Austria, and from wall biofilm and soil of a cave in the Coastal Range of the hyperarid Atacama... 相似文献
934.
Mormeneo D Manresa A Casas J Llebaria A Delgado A 《Journal of applied microbiology》2008,104(4):1075-1081
Aims: To study the growth inhibitory properties of a series of phytosphingosine (PHS) and phytoceramide (PHC) analogues. Methods and Results: A panel of two yeast (Candida albicans and Saccharomyces cerevisiae) and six moulds (Aspergillus repens, Aspergillus niger, Penicillium chrysogenum, Cladosporium cladosporioides, Arthroderma uncinatum and Penicillium funiculosum) has been used in this study. A series of new PHS and PHC analogues differing at the sphingoid backbone and the functional group at C1 position were synthesized. Conclusions: Among PHS analogues, 1‐azido derivative 1c, bearing the natural d ‐ribo stereochemistry, showed a promising growth inhibitory profile. Among PHC analogues, compound 12, with a bulky N‐pivaloyl group and a Z double bond at C3 position of the sphingoid chain, was the most active growth inhibitor. Minimal inhibitory concentration values were in the range of 23–48 μmol l?1 for 1c and 44–87 μmol l?1 for 12. Significance and Impact of the Study: Only scattered data on the antifungal activity of phytosphingolipids have been reported in the literature. This is the first time that a series of analogues of this kind are tested and compared to discern their structural requirements for antifungal activity. 相似文献
935.
Sánchez-Otero MG Valerio-Alfaro G García-Galindo HS Oliart-Ros RM 《Journal of industrial microbiology & biotechnology》2008,35(12):1687-1693
A partially purified lipase produced by the thermophile Geobacillus thermoleovorans CCR11 was immobilized by adsorption on porous polypropylene (Accurel EP-100) in the presence and absence of 0.1% Triton X-100.
Lipase production was induced in a 2.5% high oleic safflower oil medium and the enzyme was partially purified by diafiltration
(co. 500,000 Da). Immobilization conditions were established at 25 °C, pH 6, and a protein concentration of 0.9 mg/mL in the
presence and absence of 0.1% Triton X-100. Immobilization increased enzyme thermostability but there was no change in neither
the optimum pH nor in pH resistance irrelevant to the presence of the detergent during immobilization. Immobilization with
or without Triton X-100 allowed the reuse of the lipase preparation for 11 and 8 cycles, respectively. There was a significant
difference between residual activity of immobilized and soluble enzyme after 36 days of storage at 4 °C (P < 0.05). With respect to chain length specificity, the immobilized lipase showed less activity over short chain esters than
the soluble lipase. The immobilized lipase showed good resistance to desorption with phosphate buffer and NaCl; minor loses
with detergents were observed (less than 50% with Triton X-100 and Tween-80), but activity was completely lost with SDS. Immobilization
of G. thermoleovorans CCR11 lipase in porous polypropylene is a simple and easy method to obtain a biocatalyst with increased stability, improved
performance, with the possibility for re-use, and therefore an interesting potential use in commercial conditions. 相似文献
936.
Juan A. Delgado José M. Serrano Francisco López Francisco J. Acosta 《Plant Ecology》2008,197(2):269-276
The germination response of different sized seeds from individuals of a Mediterranean fire-prone shrub (Cistus ladanifer) was investigated in relation to pre-germination heating. A control (no heating), a low temperature during a short exposure
time (50°C during 5 min), a high temperature during a short exposure time (100°C during 5 min) and a high temperature during
a long exposure time (100°C during 15 min) were applied to seeds from different individual plants with different mean seed
weight. These pre-germination treatments resemble natural germination scenarios for the studied species, absence of fire,
low intensity pasture fire, typical Mediterranean shrub fire, and severe fire with high fuel load. Mean seed weight only showed
a marginally significant positive correlation with the proportion of germinated seeds whatever the pre-germination treatment.
These results suggest that seed dormancy is unrelated to seed size and that under the experimental conditions used in this
study, the effect of seed size on seed germination is low. Nevertheless, larger seeds could be favoured in natural conditions,
especially under the high competition scenario which arise after wildfires. Control seeds showed a negative correlation between
seed size and germination velocity suggesting that lighter seeds could take advantage from early germination in recruitment
events in the absence of wildfires. Nevertheless, even the lower pre-germination heating treatment turns this correlation
in not significant, suggesting a strong selection pressure (unrelated to seed size) for early germination after fire events.
In our study, different sized seeds of C. ladanifer seem to perform better under different germination scenarios suggesting that seed size variation could be maintained by the
alternation of recruitments without wildfires and recruitments after wildfire events. 相似文献
937.
938.
939.
Pérez Teresa Gómez Antoni Sanmartí Raimon Viñas Odette Ercilla Guadalupe Haro Isabel 《International journal of peptide research and therapeutics》2002,9(6):291-300
Summary Antifilaggrin autoantibodies (AFA) have described to be the most specific markers of rheumatoid arthritis (RA) and epitopes
containing citrulline within the sequence of filaggrin identified as major antigenic sites recognised by AFA. In this paper
we confirm that citrulline is an essential constituent of filaggrin related antigenic determinants recognised by RA specific
autoantibodies, thus having an important role for the development of filaggrin peptides based serological tests. Moreover,
we describe our findings on the comparative conformational analysis of filaggrin (306–324) peptide sequence and an analogue
in which two arginines were simultaneously substituted by citrulline carried out by Circular Dichroism (CD) and Fourier-Transform
Infrared Spectroscopy (FTIR). Results might contribute to the understanding of the structural features that may be important
to explain the enhanced binding characteristics of citrullinated peptides to the autoantibodies in rheumatoid arthritis. 相似文献
940.
The aim of this article is to review how sensitivity analysis has been applied to models based on Geographical Information Systems (GIS) and Multicriteria Evaluation techniques (MCE). This kind of analysis is conceived as a stage in the model evaluation that examines the extent of output variation of a model when parameters are systematically varied over a range of interest. Twenty-eight studies related to land planning processes, environmental management, and location of noxious facilities have been examined. This review reveals that sensitivity analysis is a) not a common practice, b) is more widely carried out in location of noxious facilities, and c) that the analysis most frequently used is based on the variation of the weights of the factors implied in the process to test whether it significantly modifies the results obtained. 相似文献