Chemical Compounds Responsible for Skin Allergy to Complex Mixtures: How to Identify Them?

International audienceIn the cosmetics industry, various natural complex mixtures such as botanical extracts or essential oils are used. In addition to that, finished consumer products may contain a number of constituents of natural origin but many products derived from organic synthesis too. Hence, finding skin sensitizers within this myriad of chemicals is an arduous task. Nowadays, methods validated by European dedicated instances to evaluate the allergenicity of chemicals are incapable to predict the sensitization potential of complex mixtures, even if research has progressed a lot in this direction recently. Accordingly and in this context, to identify precisely the culprit(s) responsible for skin sensitization to the mixtures is essential for risk assessment. This review is a short summary of approaches that allow identifying allergens in chemical mixtures such as bioassay-guided chemical fractionation, structure-activity relationships studies and recent methods allowing identification of reactive intermediates in natural extracts exposed to air oxidation. It is shown that a big progress has been accomplished, even if the identification of sensitizers in complex mixtures continues to be puzzling

Inhibition of cellular protein secretion by norwalk virus nonstructural protein p22 requires a mimic of an endoplasmic reticulum export signal.

Protein trafficking between the endoplasmic reticulum (ER) and Golgi apparatus is central to cellular homeostasis. ER export signals are utilized by a subset of proteins to rapidly exit the ER by direct uptake into COPII vesicles for transport to the Golgi. Norwalk virus nonstructural protein p22 contains a YXΦESDG motif that mimics a di-acidic ER export signal in both sequence and function. However, unlike normal ER export signals, the ER export signal mimic of p22 is necessary for apparent inhibition of normal COPII vesicle trafficking, which leads to Golgi disassembly and antagonism of Golgi-dependent cellular protein secretion. This is the first reported function for p22. Disassembly of the Golgi apparatus was also observed in cells replicating Norwalk virus, which may contribute to pathogenesis by interfering with cellular processes that are dependent on an intact secretory pathway. These results indicate that the ER export signal mimic is critical to the antagonistic function of p22, shown herein to be a novel antagonist of ER/Golgi trafficking. This unique and well-conserved human norovirus motif is therefore an appealing target for antiviral drug development

Self-consistent Green's functions calculation of the nucleon mean-free path

The extension of Green's functions techniques to the complex energy plane provides access to fully dressed quasi-particle properties from a microscopic perspective. Using self-consistent ladder self-energies, we find both spectra and lifetimes of such quasi-particles in nuclear matter. With a consistent choice of the group velocity, the nucleon mean-free path can be computed. Our results indicate that, for energies above 50 MeV at densities close to saturation, a nucleon has a mean-free path of 4 to 5 femtometers.Comment: 5 pages, 4 figures. Minor changes, bibliography corrected. Accepted version in Phys. Rev. Let

Forecasting volcanic ash dispersal and coeval resuspension during the April-May 2015 Calbuco eruption

Atmospheric dispersion of volcanic ash from explosive eruptions or from subsequent fallout deposit resuspension causes a range of impacts and disruptions on human activities and ecosystems. The April-May 2015 Calbuco eruption in Chile involved eruption and resuspension activities. We overview the chronology, effects, and products resulting from these events, in order to validate an operational forecast strategy for tephra dispersal. The modelling strategy builds on coupling the meteorological Weather Research and Forecasting (WRF/ARW) model with the FALL3D dispersal model for eruptive and resuspension processes. The eruption modelling considers two distinct particle granulometries, a preliminary first guess distribution used operationally when no field data was available yet, and a refined distribution based on field measurements. Volcanological inputs were inferred from eruption reports and results from an Argentina-Chilean ash sample data network, which performed in-situ sampling during the eruption. In order to validate the modelling strategy, results were compared with satellite retrievals and ground deposit measurements. Results indicate that the WRF-FALL3D modelling system can provide reasonable forecasts in both eruption and resuspension modes, particularly when the adjusted granulometry is considered. The study also highlights the importance of having dedicated datasets of active volcanoes furnishing first-guess model inputs during the early stages of an eruption.Fil: Reckziegel, Florencia Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Bustos, Emilce. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Leonardo, Mingari. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Baez, Walter Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Villarosa, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Folch Duran, Arnau. Barcelona Supercomputing Center - Centro Nacional de Supercomputacion; EspañaFil: Collini, E.. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval; ArgentinaFil: Viramonte, Jose German. Universidad Nacional de Salta; ArgentinaFil: Romero, J.. Centro de Investigación y Difusión de Volcanes de Chile; Chile. Universidad de Atacama; ChileFil: Osores, María Soledad. Comision Nacional de Actividades Espaciales; Argentina. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Role of elastic scattering in electron dynamics at ordered alkali overlayers on Cu(111)

Scanning tunneling spectroscopy of p(2x2) Cs and Na ordered overlayers on Cu(111) reveals similar line widths of quasi two-dimensional quantum well states despite largely different binding energies. Detailed calculations show that 50% of the line widths are due to electron-phonon scattering while inelastic electron-electron scattering is negligible. A frequently ignored mechanism for ordered structures, i.e., enhanced elastic scattering due to Brillouin zone back folding, contributes the remaining width.Comment: 4 pages, 2 figures, 1 tabl

Memory of Love towards Parents Questionnaire:development and psychometric evaluation

We document the development of the Memory of Love towards Parents Questionnaire—for use in multiple areas of psychology. It is designed to measure current feelings of and memory of love towards a specific parent during important time periods in childhood. In all samples (total N = 1527), we consistently found high internal reliability. We report the basic psychometrics of the 28-item subscale version in both undergraduate and US nonclinical adult samples and identified 10-item and 4-item subscale versions. The Memory of Love towards Parents Questionnaire has eight subscales: assessing mother and father separately during first, sixth, and ninth grade, as well as current feelings. We found a pattern of correlations that one would expect between existing attachment scales and the Memory of Love towards Parents Questionnaire. A factor analysis demonstrated that Memory of Love towards Parents Questionnaire items capture something different from the factors in established attachment measures. We found that the order of the subscales can be presented in a fixed order (mother-first and chronologically) without large order effects. The Memory of Love towards Parents Questionnaire demonstrated a single factor within subscales, reliability, and validity. The Memory of Love towards Parents Questionnaire can be used in clinical, social, developmental, and cognitive psychology

Effect of high pressure processing temperature on dry-cured hams with different textural characteristics

High pressure processing is mainly used to eliminate pathogenic microorganisms and extend the shelf-life of dry-cured hams, but it also modifies its texture. These changes might be different depending on the initial textural characteristics. In this study, texture, colour and colour stability were evaluated after pressurization at 600 MPa during 6 min at 7 ºC, 20 ºC and 35 ºC in samples with different textural characteristics (no pastiness, medium and high pastiness groups). HP treatments produced an increase of hardness (F0) and lightness (L*) values and a decrease of softness/pastiness (Y2 and Y90) and redness (a*) values at any processing temperatures. However, the increase of F0 and L* values was more pronounced in non–pasty samples. In samples with high pastiness and softness, HP processing at high temperature (35ºC) reduced the intensity of pastiness. However, texture of hams with non-pasty texture might be negatively affected. Therefore, the optimal temperature of HP processing depends on the textural characteristics of dry-cured hams.info:eu-repo/semantics/acceptedVersio