1,062 research outputs found
Single step fabrication of antimicrobial fibre mats from a bioengineered protein-based polymer
ProducciĂłn CientĂficaGenetically engineered protein polymers functionalized with bioactive domains have potential as multifunctional versatile materials for biomedical use. The present work describes the fabrication and characterisation of antimicrobial fibre mats comprising the antimicrobial elastin-like recombinamer (ELR) CM4-A200. The CM4-A200 protein polymer derives from the genetic fusion of the ABP-CM4 antimicrobial peptide from Bombyx mori with 200 repetitions of the pentamer VPAVG. This is the first report on non-crosslinked fibre mats fabricated with an antimicrobial ELR stable in solution. Thermal gravimetric analysis of CM4-A200 fibre mats shows one single degradation step at temperatures above 300 °C, with fibres displaying a higher thermal degradation activation. The electrospun CM4-A200 fibres display high antimicrobial activity against Gram-positive and Gram-negative bacteria with no detectable cytotoxic effects against normal human skin fibroblasts and keratinocytes, revealing the great potential of these polymers for the fabrication of biomedical materials.2018-09-10Ministerio de EconomĂa, Industria y Competitividad (Projects MAT2013-41723-R, MAT2013- 42473-R and MAT2012-38043)Junta de Castilla y LeĂłn (programa de apoyo a proyectos de investigaciĂłn â Ref. VA244U13, VA313U14
Protein-Based Films Functionalized with a Truncated Antimicrobial Peptide Sequence Display Broad Antimicrobial Activity
ProducciĂłn CientĂficaThe increasing bacterial resistance to antibiotics is driving strong demand for new antimicrobial biomaterials. This work describes the fabrication of free-standing films exhibiting antimicrobial properties by combining, in the same polypeptide chain, an elastin-like recombinamer comprising 200 repetitions of the pentamer VPAVG (A200) and an 18-amino-acid truncated variant of the antimicrobial peptide BMAP-28, termed BMAP-18. The fusion protein BMAP-18A200 was overexpressed and conveniently purified by a simplified and scalable nonchromatographic process. Free-standing films of BMAP-18A200 demonstrated to be stable without requiring cross-linking agents and displayed high antimicrobial activity against skin pathogens including Gram-negative and Gram-positive bacteria as well as unicellular and filamentous fungi. The antimicrobial activity of the films was mediated by direct contact of cells with the film surface, resulting in compromised structural integrity of microbial cells. Furthermore, the BMAP-18A200 films showed no cytotoxicity on normal human cell lines (skin fibroblasts and keratinocytes). All of these results highlight the potential of these biotechnological multifunctional polymers as new drug-free materials to prevent and treat microbial infections.FCT I.P. (Fundaçao para a Ciencia e Tecnologia, Portugal) and by the European Regional Development Fund (ERDF) through COMPETE2020Programa Operacional Competitividade e Internacionalizacao (POCI, Portugal) in the framework of the Strategic Program UID/BIA/04050/2013 (POCI-01-0145FEDER-007569).program UID/BIA/04050/2019 funded by national funds through FCT I.P.Project EcoAgriFood (NORTE-01-0145-FEDER-000009), supported by Norte Portugal Regional Operational Programme (NORTE 2020
Thermal Imaging at Plant Level to Assess the Crop-water Status in Almond Trees (cv. Guara) Under Deficit Irrigation Strategies
Almond (Prunnus dulcis Mill.) has been traditionally associated to marginal land cultivation and rain-fed agriculture in South Spain. However, in the last years, this crop is being progressively introduced in more productive agricultural areas within the Guadalquivir river basin, where the available water resources are not enough to satisfy the adequate crop-water requirements. Considering this limitation, a more precise irrigation scheduling to maximize the yield is required. Infrared thermal imaging emerges as alternative to other traditional methodologies to assess the crop-water status, especially when deficit irrigation (DI) strategies are being applied. The aim of this study was to define the methodology to assess the almond water status by means of thermal information. The trial was conducted during 2014, during the kernel-filling period, in an almond experimental orchard (SW Spain), with 5-year-old trees, subjected to three irrigation regimes: i) a full-irrigation treatment (C-100), which received 100% of ETC; ii) a regulated deficit irrigation (RDI-50), which received 100% of ETC except during the kernel filling period, when this treatment was irrigated with 50% of ETC; iii) and a low-frequency deficit irrigation treatment (LFDI), which received 100% of ETC except during the kernel filling period, when it was subjected to continuous periods of irrigation-restriction, defined in terms of the threshold values of shaded leaf water potential (Ψleaf). Three daily curves of canopy temperature (TC), stomatal conductance to water vapour (gs) and Ψleaf with measurements at 8:00, 11:00, 14:00, 17:00 and 20:00 were developed. Additionally, Crop Water Stress Index (CWSI), temperature difference between canopy and the surrounding air (ÎTcanopy-air), and the relative index to stomatal conductance (IG) obtained at different scales (canopy and row) were estimated. Significant correlations of infrared thermal information vs. Ψleaf and gs were obtained (p ⤠0.05 and p ⤠0.01), in particular, by using the thermal readings taken at 11:30, 14:30 at 17:30 h, especially robust were the relationships obtained between TC and CWSI with Ψleaf at 11:30 h; and between TC and CWSI with gs, and Ψleaf at 14:30 h. Finally, considering the infrared thermal monitoring procedure (readings at tree and row level), similar values of TC were obtained, and therefore, the images taken at row level offered a better information with a higher feasibility in terms of image processing.European Commission. Fondo Europeo de Desarrollo Regional AVA.AVA201601.1
Experimental evaluation in wireless communications
This editorial sums up relevant topics on the assessment of wireless communication systems covered by the especial issue entitled "Experimental Evaluation in Wireless Communications". The topics include practical aspects on the implementation of distributed asynchronous non-linear kernel methods over wireless sensor networks; localization methods based on the exploitation of radio-frequency identification (RFID) wireless sensors and cellular networks or on sparsity approximations; channel sounding and assessment of broadband orthogonal frequency-division multiplexing (OFDM)-based wireless systems in high-speed vehicular communications; coexistence analysis of femtocell-based and outdoor-to-indoor systems; techniques for peak-to-average power ratio (PAPR) reduction; new solutions for baseband and radio frequency (RF) hardware impairments in full-duplex wireless systems; and, finally, suitability of interference alignment for broadband indoor wireless communications
Systematic study of optical potential strengths in reactions on Sn 120 involving strongly bound, weakly bound, and exotic nuclei
We present new experimental angular distributions for the elastic scattering of Li6+Sn120 at three bombarding energies. We include these data in a wide systematic involving the elastic scattering of He4,6,Li7, Be9,B10, and O16,18 projectiles on the same target at energies around the respective Coulomb barriers. Considering this data set, we report on optical model analyses based on the double-folding SĂŁo Paulo potential. Within this approach, we study the sensitivity of the data fit to different models for the nuclear matter densities and to variations in the optical potential strengths.Fil: Alvarez, M. A. G.. Universidad de Sevilla; EspaĂąaFil: FernĂĄndez GarcĂa, J. P.. Universidad de Sevilla; EspaĂąaFil: LeĂłn GarcĂa, J. L.. Universidad de Sevilla; EspaĂąaFil: RodrĂguez Gallardo, M.. Universidad de Sevilla; EspaĂąaFil: Gasques, L. R.. Universidade de Sao Paulo; BrasilFil: Chamon, L. C.. Universidade de Sao Paulo; BrasilFil: Zagatto, V. A. B.. Universidade de Sao Paulo; BrasilFil: LĂŠpine Szily, A.. Universidade de Sao Paulo; BrasilFil: Oliveira, J. R. B.. Universidade de Sao Paulo; BrasilFil: Scarduelli, V.. Universidade Federal Fluminense; BrasilFil: Carlson, B. V.. Instituto Tecnologico de Aeronautica.; BrasilFil: Casal, J.. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Arazi, Andres. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas; Argentina. ComisiĂłn Nacional de EnergĂa AtĂłmica; ArgentinaFil: Torres, D. A.. Universidad Nacional de Colombia; ColombiaFil: Ramirez, F.. Universidad Nacional de Colombia; Colombi
Biotechnological production and application of fructooligosaccharides
Currently, prebiotics are all carbohydrates of relatively short chain length. An important group is the fructooligosaccharides, which are a special kind of prebiotics associated to their selective stimulation of the activity of certain groups of colonic bacteria that have a positive and beneficial effect on intestinal microbiota, reducing incidence of gastrointestinal infections, respiratory and also possessing a recognized bifidogenic effect. Traditionally, these prebiotic compounds have been obtained through extraction processes from some plants, as well as through enzymatic hydrolysis of sucrose. However, different fermentative methods have also been proposed for the production of fructooligosaccharides, such as solid-state fermentation utilizing various agroindustrial by-products. By optimizing the culture parameters, fructooligosaccharides yields and productivity can be improved. The use of immobilized enzymes and cells has also been proposed as being an effective and economic method for large-scale production of fructooligosaccharides. This paper is an overview on the results of recent studies on fructooligosacharides biosynthesis, physicochemical properties, sources, biotechnological production and applications.The authors thank the National Council of Science and Technology of Mexico (CONACYT) for funding this study. D. A. Flores-Maltos thank the CONACYT for the financial support provided for her postgraduate studies in the Food Science and Technology Program, Universidad Autonoma de Coahuila, Mexico
Low nadir CD4+ T-cell counts predict gut dysbiosis in HIV-1 infection
Human immunodeficiency virus (HIV)-1 infection causes severe gut and systemic immune damage, but its effects on the gut microbiome remain unclear. Previous shotgun metagenomic studies in HIV-negative subjects linked low-microbial gene counts (LGC) to gut dysbiosis in diseases featuring intestinal inflammation. Using a similar approach in 156 subjects with different HIV-1 phenotypes, we found a strong, independent, dose-effect association between nadir CD4+ T-cell counts and LGC. As in other diseases involving intestinal inflammation, the gut microbiomes of subjects with LGC were enriched in gram-negative Bacteroides, acetogenic bacteria and Proteobacteria, which are able to metabolize reactive oxygen and nitrogen species; and were depleted in oxygen-sensitive methanogenic archaea and sulfate-reducing bacteria. Interestingly, subjects with LGC also showed increased butyrate levels in direct fecal measurements, consistent with enrichment in Roseburia intestinalis despite reductions in other butyrate producers. The microbiomes of subjects with LGC were also enriched in bacterial virulence factors, as well as in genes associated with beta-lactam, lincosamide, tetracycline, and macrolide resistance. Thus, low nadir CD4+ T-cell counts, rather than HIV-1 serostatus per se, predict the presence of gut dysbiosis in HIV-1 infected subjects. Such dysbiosis does not display obvious HIV-specific features; instead, it shares many similarities with other diseases featuring gut inflammation
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
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