364 research outputs found
Eficacia biodescontaminante obtenida mediante la aplicación de Virkon®, Perasafe® e hidróxido sódico sobre superficies de alto riesgo microbiológico
La eficacia de la actividad biodescontaminante de los productos Virkon®, Perasafe® e hidróxido sódico, ha sido evaluada. Los compuestos fueron ensayados en boxes de laboratorios de contención con bioseguridad nivel 3 (NCB3), destinados a alojar animales de experimentación para el estudio de peste porcina africana (PPA), fiebre aftosa (FA) y virus del Nilo Occidental (VNO). Las muestras procedentes de diferentes puntos fueron obtenidas mediante placas RODAC, antes y después de la aplicación del tratamiento desinfectante sobre la superficie ensayada, y los resultados obtenidos fueron expresados como unidades formadoras de colonias por mililitro (ufc/ml). Los resultados obtenidos indican que todos los compuestos ensayados demostraron un alto nivel de eficacia biodescontaminante, pero sin embargo el efecto inducido el compuesto Perasafe® aportó un nivel de eficacia superior al obtenido con los otros compuestos. Así, estos resultados permiten afirmar la idoneidad de Perasafe® para la desinfección de espacios con nivel 3 de bioseguridad.Biodecontaminant effectiveness obtained in surfaces treated with Virkon®, Perasafe®, and sodium hydroxide has been evaluated. The selected compounds were used in boxes from Biosafety Level 3 containment laboratories (NCB3) for animals exposed to classical swine fever (CSF), foot and mooth disease (FMD), and west nile virus (WNV). The samples from selected points were obtained by mean RODAC plates, before and after to the use of selected compounds on surfaces, and the results obtained were expressed as colony-forming units per milliliter (cfu/ml). Results shown that all compounds assayed demonstrated high biodecontaminant efficacy levels; but however Perasafe® was more effective than others compounds assayed. Thus, these results allow affirming that Perasafe® is suitable for the disinfection of surfaces from NCB3 spaces
Green spaces and cognitive development in primary schoolchildren
© 2015, National Academy of Sciences. All rights reserved. Exposure to green space has been associated with better physical and mental health. Although this exposure could also influence cognitive development in children, available epidemiological evidence on such an impact is scarce. This study aimed to assess the association between exposure to green space and measures of cognitive development in primary schoolchildren. This study was based on 2,593 schoolchildren in the second to fourth grades (7-10 y) of 36 primary schools in Barcelona, Spain (2012-2013). Cognitive development was assessed as 12-mo change in developmental trajectory of working memory, superior working memory, and inattentiveness by using four repeated (every 3 mo) computerized cognitive tests for each outcome. We assessed exposure to green space by characterizing outdoor surrounding greenness at home and school and during commuting by using high-resolution (5 m x5 m) satellite data on greenness (normalized difference vegetation index). Multilevel modeling was used to estimate the associations between green spaces and cognitive development. We observed an enhanced 12-mo progress in working memory and superior working memory and a greater 12-mo reduction in inattentiveness associated with greenness within and surrounding school boundaries and with total surrounding greenness index (including greenness surrounding home, commuting route, and school). Adding a traffic-related air pollutant (elemental carbon) to models explained 20-65% of our estimated associations between school greenness and 12-mo cognitive development. Our study showed a beneficial association between exposure to green space and cognitive development among schoolchildren that was partly mediated by reduction in exposure to air pollution
Pentagonal nanowires: a first-principles study of atomic and electronic structure
We performed an extensive first-principles study of nanowires in various
pentagonal structures by using pseudopotential plane wave method within the
density functional theory. Our results show that nanowires of different types
of elements, such as alkali, simple, transition and noble metals and inert gas
atoms, have a stable structure made from staggered pentagons with a linear
chain perpendicular to the planes of the pentagons and passing through their
centers. This structure exhibits bond angles close to those in the icosahedral
structure. However, silicon is found to be energetically more favorable in the
eclipsed pentagonal structure. These quasi one dimensional pentagonal nanowires
have higher cohesive energies than many other one dimensional structures and
hence may be realized experimentally. The effect of magnetic state are examined
by spin-polarized calculations. The origin of the stability are discussed by
examining optimized structural parameters, charge density and electronic band
structure, and by using analysis based on the empirical Lennard-Jones type
interaction. Electronic band structure of pentagonal wires of different
elements are discussed and their effects on quantum ballistic conductance are
mentioned. It is found that the pentagonal wire of silicon exhibits metallic
band structure.Comment: 4 figures, accepted for publication in Phys. Rev.
Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.
The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity
Domain integral equations for electromagnetic band-gap slab simulations
Trabajo presentado al International Symposium on Electromagnetic Theory, URSI 2004.Electromagnetic band-gap substrates o er advantages regarding cross-coupling in sub-mm range imaging
array applications. Electromagnetic scattering by such substrates may e ectively be formulated in terms of integro-
di erential equations. The scattered elds are evaluated via the spectral domain in which the 3-D problem reduces to
an in nite system of coupled 1-D integro-di erential equations. The associated matrix-vector products are dominated
by FFTs. For moderate frequencies an elementary preconditioner in combination with a prudent initial estimate usually
su ces to reach rapid convergence using the transpose-free quasi-minimal residual method.The research presented above has been financially supported by ESA/ESTEC, under Contract No.
15632/01/NL/JA
Association of Serum Ferritin Levels Before Start of Conditioning With Mortality After alloSCT - A Prospective, Non-interventional Study of the EBMT Transplant Complications Working Party
Elevated serum ferritin levels occur due to iron overload or during inflammation and macrophage activation. A correlation of high serum ferritin levels with increased mortality after alloSCT has been suggested by several retrospective analyses as well as by two smaller prospective studies. This prospective multicentric study aimed to study the association of ferritin serum levels before start of conditioning with alloSCT outcome. Patients with acute leukemia, lymphoma or MDS receiving a matched sibling alloSCT for the first time were considered for inclusion, regardless of conditioning. A comparison of outcomes between patients with high and low ferritin level was performed using univariate analysis and multivariate analysis using cause-specific Cox model. Twenty centers reported data on 298 alloSCT recipients. The ferritin cut off point was determined at 1500 mu g/l (median of measured ferritin levels). In alloSCT recipients with ferritin levels above cut off measured before the start of conditioning, overall survival (HR = 2.5, CI = 1.5-4.1, p = 0.0005) and progression-free survival (HR = 2.4, CI = 1.6-3.8, p <0.0001) were inferior. Excess mortality in the high ferritin group was due to both higher relapse incidence (HR = 2.2, CI = 1.2-3.8, p = 0.007) and increased non-relapse mortality (NRM) (HR = 3.1, CI = 1.5-6.4, p = 0.002). NRM was driven by significantly higher infection-related mortality in the high ferritin group (HR = 3.9, CI = 1.6-9.7, p = 0.003). Acute and chronic GVHD incidence or severity were not associated to serum ferritin levels. We conclude that ferritin levels can serve as routine laboratory biomarker for mortality risk assessment before alloSCT.Peer reviewe
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