309 research outputs found
Preparation and characterization of polymeric microspheres for Cr(VI) extraction
Microspheres (MS) from different polymers were prepared using two routes. Route A: process of phase inversion with solutions of polysulfone (PSf) in dichloromethane (DCM) and polyvinylpyrrolidone (PVP) as additive. Different weight ratios of PSf-PVP were used in the MS preparation. Route B: MS were obtained by cross-linking in emulsion using a commercial silicone as raw material. The obtained MS were analysed according to their morphological-structural characteristics and in relation to their Cr(VI) extraction capacity using impregnated MS with Aliquat 336. The results obtained showed that MS prepared with PSf-PVP have both less specific surfaces and relative porosities when the proportion of PVP in the mixture is increased. Extraction tests of ion Cr(VI) indicated that synthesized MS have adequate structural characteristics and interesting adsorptive properties which give rise to impregnating selective extractants. Impregnated microspheres with Aliquat 336 prepared from 2:1 PSf-PVP ratio achieved the highest Cr(VI) extractive performance (92% of Cr extraction for contact time of 60 min) and the best breakthrough point in column tests (up to 10 h in the first cycle).Fil: Ochoa, Nelio Ariel. Universidad Nacional de San Luis. Facultad de Ciencias Fisico Matematicas y Naturales. Departamento de Fisica. Laboratorio de Ciencias de Superficies y Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Illanes, Cristian Omar. Universidad Nacional de San Luis. Facultad de Ciencias Fisico Matematicas y Naturales. Departamento de Fisica. Laboratorio de Ciencias de Superficies y Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Marchese, Jose. Universidad Nacional de San Luis. Facultad de Ciencias Fisico Matematicas y Naturales. Departamento de Fisica. Laboratorio de Ciencias de Superficies y Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Basualto, C.. Universidad de Chile; ChileFil: Valenzuela, Fernando R.. Universidad de Chile; Chil
Bestrophin1 Channels are Insensitive to Ethanol and Do not Mediate Tonic GABAergic Currents in Cerebellar Granule Cells
The granule cell layer of the cerebellum functions in spatio-temporal encoding of information. Granule cells (GCs) are tonically inhibited by spillover of GABA released from Golgi cells and this tonic inhibition is facilitated by acute ethanol. Recently, it was demonstrated that a specialized Ca2+-activated anion-channel, bestrophin1 (Best1), found on glial cells, can release GABA that contributes up to 50–75% of the tonic GABAergic current. However, it is unknown if ethanol has any actions on Best1 function. Using whole-cell electrophysiology, we found that recombinant Best1 channels expressed in HEK-293 cells were insensitive to 40 and 80 mM ethanol. We attempted to measure the Best1-mediated component of the tonic current in slices using 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB). We confirmed that this agent blocks recombinant Best1 channels. Unexpectedly, we found that NPPB significantly potentiated the tonic current and the area and decay of GABAA-mediated spontaneous inhibitory post-synaptic currents (IPSCs) in GCs in rodent slices under two different recording conditions. To better isolate the Best1-dependent tonic current component, we blocked the Golgi cell component of the tonic current with tetrodotoxin and found that NPPB similarly and significantly potentiated the tonic current amplitude and decay time of miniature IPSCs. Two other Cl−-channel blockers were also tested: 4′-diisothiocyanatostilbene-2,2′-disulfonic acid disodium salt hydrate (DIDS) showed no effect on GABAergic transmission, while niflumic acid (NFA) significantly suppressed the tonic current noise, as well as the mIPSC frequency, amplitude, and area. These data suggest that acute ethanol exposure does not modulate Best1 channels and these findings serve to challenge recent data indicating that these channels participate in the generation of tonic GABAergic currents in cerebellar GCs
Evaluation of the pilot program to reduce salt/sodium in bread in Santiago of Chile
Indexación: Web of Science; ScieloAntecedentes: Considerando la alta carga de enfermedades asociadas a un excesivo consumo de sal, Chile inició un programa piloto entre el Ministerio de Salud (MINSAL), la Federación de Industriales Panaderos (FECHIPAN) y la Asociación Chilena de Supermercados (ASACH) con el propósito de lograr una disminución paulatina de la sal con que se fabrica el pan. Objetivo: Analizar la concentración de sodio (mg/100 g) en muestras de pan de panaderías adheridas al programa y panaderías no participantes, del Gran Santiago. Materiales y métodos: Estudio transversal analítico; muestreo aleatorio de dos muestras de pan en cinco panaderías del programa piloto y cinco panaderías control. Análisis de sodio por espectrofoto-metría de absorción atómica y determinación del promedio de éste en las muestras (mg/100 g de pan). Para la comparación de promedios se utilizó t de Student, considerando significativo un p < 0,05. Resultados: La concentración promedio de sodio en el pan en el grupo control fue 597,2 ± 106,4 mg/100 g y en el grupo intervenido 600,9 ± 106,2 mg/100 g, sin diferencias significativas entre ellos. Existe bastante variabilidad en los niveles de sodio en ambos grupos, con valores extremos de 403 y 824 mg/100 g. Discusión: La concentración de sodio en el pan fue similar en ambos grupos. La reducción del sodio en panaderías no participantes en el programa, sugiere preocupación de la industria por fabricar un pan más saludable. Son necesarios estudios con mayor representatividad para conocer mejor la realidad nacional.Introduction: Considering the high burden of disease associated with excessive salt intake of the population, Chile initiated a pilot program between the Ministry of Health (MINSAL), the Industrial Bakers Federation (FECHIPAN) and the Chilean Association of Supermarkets (ASACH) in order to achieve a gradual reduction of salt in bread. Objective: To analyze the amount of sodium in bread samples from bakeries belonging to the program and those not participating in Santiago. Materials and methods: Cross-sectional study with random sampling of two products in five pilot and five control bakeries. Sodium was analysed by atomic absorption spectrophotometry and the mean was used for analysis (mg/100 g of bread). For comparison the Student's t test was utilized and significance was established at p <0,05. Results: The average sodium concentration in the control group was 597,2 ± 106,4 mg/100 g bread while in the experimental group was 600,9 ± 106,2 mg/100 g bread showing no significant differences between them. There was considerable variability in the levels of sodium in both groups, with values ranging from 403 to 824 mg/100 g. Discussion: The concentration of sodium in the bread was similar in both groups, suggesting a reduction in salt content in the control bakeries. More studies are needed to better understand the national reality in this matter.http://ref.scielo.org/jk3rk
Performance and reference data in the jump squat at different relative loads in elite sprinters, rugby players, and soccer players
The aims of this study were to compare the outcomes and provide reference data for a set of barbell mechanical parameters collected via a linear velocity transducer in 126 male sprinters (n = 62), rugby players (n = 32), and soccer players (n = 32). Bar-velocity, bar-force, and bar-power outputs were assessed in the jump-squat exercise with jump-squat height determined from bar-peak velocity. The test started at a load of 40% of the athletes\u27 body mass (BM), and a load of 10% of BM was gradually added until a clear decrement in the bar power was observed. Comparisons of bar variables among the three sports were performed using a one-way analysis of variance. Relative measures of bar velocity, force, and power, and jump-squat height were significantly higher in sprinters than in rugby (difference ranging between 5 and 35%) and soccer (difference ranging between 5 and 60%) players across all loads (40-110% of BM). Rugby players exhibited higher absolute bar-power (mean difference = 22%) and bar-force (mean difference = 16%) values than soccer players, but these differences no longer existed when the data were adjusted for BM (mean difference = 2.5%). Sprinters optimized their bar-power production at significantly greater relative loads (%BM) than rugby (mean difference = 22%) and soccer players (mean difference = 25%); nonetheless, all groups generated their maximum bar-power outputs at similar bar velocities. For the first time, we provided reference values for the jump-squat exercise for three different bar-velocity measures (i.e., mean, mean propulsive, and peak velocity) for sprinters, rugby players, and soccer players, over a wide range of relative loads. Practitioners can use these reference values to monitor their athletes and compare them with top-level sprinters and team-sport players
Squat and countermovement jump performance across a range of loads: A comparison between Smith machine and free weight execution modes in elite sprinters
The aims of this study were to: 1) provide and compare the height achieved during Smith machine (SM) and free weight (FW) loaded jumps executed over a wide spectrum of loads (40–120 % of body mass [BM]); and 2) test the difference between loaded and unloaded squat jump (SJ) and countermovement jump (CMJ) attempts in ten highly trained male sprinters. On the first visit, athletes performed unloaded SJ and CMJ, loaded SJ with loads corresponding to 40, 60, 80, 100, and 120 % BM, and loaded CMJ at 100% BM using an Olympic barbell (FW). On the second visit, they performed loaded SJ and CMJ tests under the same loading conditions on the SM device and, subsequently, a half-squat one-repetition maximum (1RM) assessment. The relative strength (RS = 1RM/BM) of the athletes was 2.54 ± 0.15. Loaded SJ performance was similar between SM and FW, and across all loading conditions. Differences in favour of CMJ (higher jump heights compared with SJ) were superior in the unloaded condition but decreased progressively as a function of loading. In summary, sprinters achieved similar SJ heights across a comprehensive range of loads, regardless of the execution mode (FW or SM). The positive effect of the countermovement on jump performance is progressively reduced with increasing load
Pomegranate (Punica granatum L.) Peel Extracts as Antimicrobial and Antioxidant Additives Used in Alfalfa Sprouts
Aqueous and ethanolic pomegranate peel extracts (PPE) were studied as a source of
phenolic compounds with antimicrobial, anti-quorum sensing, and antioxidant properties. The
aqueous extract showed higher total phenolic and flavonoid content (153.43 mg GAE/g and 45.74,
respectively) and antioxidant capacity (DPPH radical inhibition: 86.12%, ABTS radical scavenging
capacity: 958.21 mg TE/dw) compared to the ethanolic extract. The main phenolic compounds
identified by UPLC-DAD were chlorogenic and gallic acids. The aqueous PPE extract showed
antimicrobial activity against Listeria monocytogenes, Salmonella Typhimurium, Candida tropicalis (MICs
19–30 mg/mL), and anti-quorum sensing activity expressed as inhibition of Chromobacterium violaceum
violacein production (%). The aqueous PPE extracts at 25 mg/mL applied on alfalfa sprouts reduced
psychrophilic bacteria (1.12 Log CFU/100 g) and total coliforms (1.23 Log CFU/100 g) and increased
the antioxidant capacity of the treated sprouts (55.13 mol TE/100 g (DPPH) and 126.56 mol
TE/100 g (ABTS)) compared to untreated alfalfa. This study emphasizes PPE’s antioxidant and
antimicrobial activities in alfalfa sprouts preservation
Epidemiological Pathology of Dementia: Attributable-Risks at Death in the Medical Research Council Cognitive Function and Ageing Study
Researchers from the Medical Research Council Cognitive Function and Ageing Neuropathology Study carry out an analysis of brain pathologies contributing to dementia, within a cohort of elderly individuals in the UK who agreed to brain donation
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
Integrating Clinical Probability into the Diagnostic Approach to Idiopathic Pulmonary Fibrosis: An International Working Group Perspective
Background. When considering the diagnosis of idiopathic pulmonary fibrosis (IPF), experienced
clinicians integrate clinical features that help to differentiate IPF from other fibrosing interstitial lung
diseases, thus generating a “pre-test” probability of IPF. The aim of this international working group
perspective was to summarize these features using a tabulated approach similar to chest HRCT and
histopathologic patterns reported in the international guidelines for the diagnosis of IPF, and to help
formally incorporate these clinical likelihoods into diagnostic reasoning to facilitate the diagnosis of
IPF.
Methods. The committee group identified factors that influence the clinical likelihood of a diagnosis
of IPF, which was categorized as a pre-test clinical probability of IPF into “high” (70-100%),
“intermediate” (30-70%), or “low” (0-30%). After integration of radiological and histopathological
features, the post-test probability of diagnosis was categorized into “definite” (90-100%), “high
confidence” (70-89%), “low confidence” (51-69%), or “low” (0-50%) probability of IPF.
Findings. A conceptual Bayesian framework was created, integrating the clinical likelihood of IPF
(“pre-test probability of IPF”) with the HRCT pattern, the histopathology pattern when available,
and/or the pattern of observed disease behavior into a “post-test probability of IPF”. The diagnostic
probability of IPF was expressed using an adapted diagnostic ontology for fibrotic interstitial lung
diseases.
Interpretation. The present approach will help incorporate the clinical judgement into the diagnosis
of IPF, thus facilitating the application of IPF diagnostic guidelines and, ultimately improving
diagnostic confidence and reducing the need for invasive diagnostic techniques
Lo glocal y el turismo. Nuevos paradigmas de interpretación.
El estudio del turismo se realiza desde múltiples escalas y enfoques, este libro aborda muchos temas que es necesario discutir desde diversas perspectivas; es el caso de la reflexión sobre la propia disciplina y sus conceptos, así como los asuntos específicos referidos al impacto territorial, los tipos de turismo, las cuestiones ambientales, el tema de la pobreza, la competitividad, las políticas públicas, el papel de las universidades, las áreas naturales protegidas, la sustentabilidad, la cultura, el desarrollo, la seguridad, todos temas centrales documentados y expuestos con originalidad y dominio del asunto. Lo multiescalar es básico para la comprensión del sistema turístico, sistema formado de procesos globales, regionales y locales. El eje de discusión del libro es lo glocal, esa interacción entre lo nacional y local con lo global
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