Fluids and melts in planetary interiors: From crust to core-mantle boundaries

International audienceAqueous fluids and melts (silicate, carbonate/carbonatites or metallic melts) are major vectors of massand heat transfer in planetary interiors and play an important role in a variety of geochemical andgeodynamical processes that shape the internal and surficial evolution of planetary systems. Theseprocesses occur over a broad range of pressure and temperatures that span from shallow crustal conditions(e.g., magma chamber processes, ore deposit formation) to the deep core-mantle boundaries (e.g.,planetary differentiation), and they are strongly influenced by the physical, chemical and structuralproperties of aqueous fluids and melts at relevant pressure and temperature conditions. Over the lastdecade, major progress has been made in the determination of the properties of aqueous fluids and meltsthanks to the development of advanced experimental and computational methods. The goal of this specialissue is to highlight some of these advancements and to discuss new views and open questions related tomass transfer and melting in planetary interiors, from crustal conditions to core-mantle boundaries andfrom the atomic to the planetary scales

Brillouin scattering study on the single-crystal elastic properties of natrolite and analcime zeolites

Copyright © 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 98 (2005) and may be found at http://link.aip.org/link/?jap/98/053508The Brillouin light-scattering technique was used to investigate the single-crystal elastic properties of two aluminosilicate zeolites, natrolite (NAT) and analcime (ANA), at ambient conditions. An inversion of the acoustic velocity data results in the full set of elastic stiffness moduli (Cij's) for both materials. From the single-crystal moduli the aggregate adiabatic bulk moduli (Ks), shear moduli (G), and Poisson's ratios (v) were found to be Ks=48.5(1.0) GPa, G=31.6(1.0) GPa, and v =0.232(5) for NAT, and Ks=59.8(1.2) GPa, G=32.1(1.0) GPa, and v=0.272(5) for ANA (Voigt-Reuss-Hill averages). The bulk and shear moduli of both zeolites are relatively low compared with those of densely packed aluminosilicates, reflecting an open framework structure of (Al,SiO4) tetrahedra which is easily deformed by bending the Si–O–Al angles. As expected for a less dense crystal, NAT is softer and more compressible than ANA. An evaluation of the directional Young's moduli shows that the compressibility of NAT is nearly uniform along the [100] and [010] axes, while [001] is stiffer, in agreement with previous compression studies. We do not find experimental evidence of negative Poisson's ratios for NAT zeolites as predicted by recent theoretical calculations

Selective Interactions of Valeriana officinalis Extracts and Valerenic Acid with [3H]Glutamate Binding to Rat Synaptic Membranes

Although GABA neurotransmission has been suggested as a mechanism for Valeriana officinalis effects, CNS depression can also be evoked by inhibition of ionotropic (iGluR) and metabotropic glutamate receptors (mGluR). In this study, we examined if aqueous valerian extract interacted with glutamatergic receptors. Freshly prepared aqueous valerian extract was incubated with rat cortical synaptic membranes in presence of 20 nM [3H]Glutamate. Aqueous valerian extract increased [3H]Glutamate binding from 1 × 10−7 to 1 × 10−3 mg/mL. In the presence of (2S,1′S,2′S)-2-(Carboxycyclopropyl)glycine (LCCG-I) and (2S,2′R,3′R)-2-(2′,3′-Dicarboxycyclopropyl)glycine (DCG-IV), Group II mGluR agents, valerian extract markedly decreased [3H]Glutamate binding, while (2S)-2-amino-3-(3,5-dioxo-1,2,4-oxadiazolidin-2-yl) propanoic acid) (quisqualic acid, QA), Group I mGluR agonist, increased [3H]Glutamate binding. At 0.05 mg/mL aqueous valerian extract specifically interacted with kainic acid NMDA and AMPA receptors. Valerenic acid, a marker compound for Valeriana officinalis, increased the [3H]Glutamate binding after 1.6 × 10−2 mg/mL, and at 0.008 mg/mL it interacted only with QA (Group I mGluR). The selective interactions of valerian extract and valerenic acid with Group I and Group II mGluR may represent an alternative explanation for the anxiolytic properties of this plant

Pressure dependence of intra- and interlayer excitons in 2H-MoS2_2 bilayers

The optical and electronic properties of multilayer transition metal dichalcogenides differ significantly from their monolayer counterparts due to interlayer interactions. The separation of individual layers can be tuned in a controlled way by applying pressure. Here, we use a diamond anvil cell to compress bilayers of 2H-MoS$_2$ in the gigapascal range. By measuring optical transmission spectra, we find that increasing pressure leads to a decrease in the energy splitting between the A and interlayer exciton. Comparing our experimental findings with ab initio calculations, we conclude that the observed changes are not due to the commonly assumed hydrostatic compression. This effect is attributed to the MoS$_2$ bilayer adhering to the diamond, which reduces in-plane compression. Moreover, we demonstrate that the distinct real-space distributions and resulting contributions from the valence band account for the different pressure dependencies of the inter- and intralayer excitons in compressed MoS$_2$ bilayers.Comment: 8 pages, 5 figure

Automated pipeline processing X‐ray diffraction data from dynamic compression experiments on the Extreme Conditions Beamline of PETRA III

Presented and discussed here is the implementation of a software solution that provides prompt X‐ray diffraction data analysis during fast dynamic compression experiments conducted within the dynamic diamond anvil cell technique. It includes efficient data collection, streaming of data and metadata to a high‐performance cluster (HPC), fast azimuthal data integration on the cluster, and tools for controlling the data processing steps and visualizing the data using the DIOPTAS software package. This data processing pipeline is invaluable for a great number of studies. The potential of the pipeline is illustrated with two examples of data collected on ammonia–water mixtures and multiphase mineral assemblies under high pressure. The pipeline is designed to be generic in nature and could be readily adapted to provide rapid feedback for many other X‐ray diffraction techniques, e.g. large‐volume press studies, in situ stress/strain studies, phase transformation studies, chemical reactions studied with high‐resolution diffraction etc

First reported double drug–drug interaction in a cancer renal patient under everolimus treatment: therapeutic drug monitoring and review of literature

Everolimus is an inhibitor of mammalian target of rapamycin (mTOR) used in both transplantation and cancer treatment (breast, renal and neuroendocrine). In transplantation, therapeutic drug monitoring (TDM) is recommended due to the potential drug-drug interactions with chronic medications, which can affect everolimus pharmacokinetics. In cancer treatment, everolimus is used at higher doses than in transplantation and without a systematic drug monitoring.We present a case report of a 72-year-old woman with epilepsy history to whom everolimus 10 mg QD was prescribed as third line of treatment for renal cell carcinoma (RCC). The potential drug interactions between everolimus and the patient's chronic medications, carbamazepine and phenytoin, are significant as both are known as strong inducers CYP3A4 metabolism, potentially leading to underexposure to everolimus.TDM of everolimus was recommended by the pharmacist. The literature suggests that a minimum plasma concentration (Cminss) of everolimus over 10 ng/ml is associated with better response to treatment and progression-free survival (PFS). The patient's everolimus dose had to be increased until 10 mg BID, and regular monitoring of everolimus levels showed an increase in Cminss from 3.7 ng/ml to 10.8 ng/ml.This case highlights the importance of checking for potential drug interactions and monitoring everolimus levels in patients on chronic medication, especially those with several inducers or inhibitors of CYP3A4 metabolism. TDM can help to ensure that patients are treated with their optimal dose, which can improve the effectiveness of the treatment or minimize the risk of toxicities

Plan estratégico de alianza Tesla-Delta Signal 2022-2026

Delta Signal Corporation, se fundó en 1992 en Ohio (Estados Unidos), siendo su Core de negocio la manufactura y distribución de autopartes eléctricas y electrónicas del rubro Automotriz. En, los últimos 4 años (2018-2021) ha apostado por una estrategia enfocada en la diferenciación, para recuperar su cuota de mercado global e incrementar sus ventas, invirtiendo 200 USD MM en iniciativas de valor agregado que le permitan posicionarse en el mercado de automóviles. Se diseñó una nueva Estrategia Competitiva de Diferenciación basada en Innovación, se manejaron herramientas de análisis interno y externo, metodología del Balanced Scorecard (BSC). Asimismo, se destinó un Presupuesto de 255MM para llevar a cabo 5 Planes funcionales; el Plan de Operaciones cuyo objetivo principal es agilizar la co-creación del Sistema Integrado Autónomo Delta 5.0 que permita obtener 35 patentes en tecnologías emergentes, asimismo, un Plan de Recursos que permita atraer, desarrollar e inspirar al mejor talento en investigación y desarrollo y propicie una Cultura Innovadora Sostenible que permita contar con un 95% de personal entrenado y especializado en tecnologías de vanguardia, por otro lado el Plan de Responsabilidad Social está orientada a lograr una Cadena de Suministro que cuente con un 85% de productos e insumos sostenibles y el Plan de Marketing consolidará un crecimiento de ventas en un 70%

Bocio multinodular tóxico (enfermedad de Plummer): reporte de un caso

El bocio multinodular tóxico (BMNT) o enfermedad de Plummer, se define como un aumento de volumen crónico de la glándula tiroides asociado a hipertiroidismo en ausencia de enfermedad autoinmune o neoplasia. Existen factores de riesgo asociados como tabaquismo, sexo, edad y predisposición genética. En el presente trabajo se analiza el caso de un paciente masculino de 75 años de edad que presentó aumento de volumen en región cervical anterior izquierda, asociado a dolor de moderada intensidad, signos de flogosis y, concomitantemente, disfagia y pérdida de peso. Como antecedente importante refirió tabaquismo. Se realizó hematología completa, glicemia y perfil de hormonas tiroideas; se evidenciaron niveles aumentados de T4 con niveles normales de TSH y ausencia de anticuerpos TPO. Se realizó ecografía tiroidea de alta resolución, reportando un aumento difuso del tamaño de la glándula tiroides a predominio del lóbulo izquierdo en todos sus ejes, sin evidencia de ganglios linfáticos aumentados de tamaño. Se estableció diagnóstico de BMNT asociado a diabetes mellitus tipo II, instaurándose un tratamiento con metimazol y metformina combinado con sitagliptina. Posterior a 10 días se evidenció mejoría en el perfil tiroideo, glicemia y disminución del bocio. Es importante considerar la presentación clínica de esta enfermedad, la cual es poco frecuente y se relaciona con la clínica manifestada por el paciente, así como los beneficios de la terapia con drogas antitiroideas en los casos de BMNT en pacientes ancianos. Palabras clave: Bocio; hipertiroidismo; tirotoxicosis; bocio multinodular tóxico; terapia antitiroidea

Deformation Mechanisms, Microstructures, and Seismic Anisotropy of Wadsleyite in the Earth's Transition Zone

Wadsleyite is the dominant mineral of the upper portion of the Earth's mantle transition zone (MTZ). As such, understanding plastic deformation of wadsleyite is relevant for the interpretation of observations of seismic signals from this region in terms of mantle flow. Despite its relevance, however, the deformation mechanisms of wadsleyite and their effects on microstructures and anisotropy are still poorly understood. Here, we present the results of new deformation experiments on polycrystalline wadsleyite at temperatures of 1400–1770 K and pressures between 12.3 and 20.3 GPa in the laser-heated diamond anvil cell. We rely on multigrain X-ray crystallography to follow the evolution of individual grain orientations and extract lattice preferred orientations at the sample scale at different steps of the experiments. A comparison of experimental results of our work and the literature with polycrystal plasticity simulations, indicates that ⟨111⟩{101} is the most active slip system of dislocations in wadsleyite at all investigated conditions. Secondary slip systems such as [001](010), [100](001), and [100]{0kl}, however, play a critical role in the resulting microstructures and their activity depends on both temperature and water content, from which we extract an updated deformation map of wadsleyite at MTZ conditions. Lastly, we propose several seismic anisotropy models of the upper part of the MTZ, depending on temperature, geophysical context, and levels of hydration that will be useful for the interpretation of seismic signals from the MTZ in terms of mantle flow and water conten

Maerl grounds : habitats of high biodiversity in European seas

The BIOMAERL programme is a 3-year collaborative programme between laboratories in UK, Spain, France and Malta which began in February 1996. Its main plans are described in the workplan. A full inventory of the biological composition (biodiversity) of maerl bed assemblages in these regions therefore has yet to be completed, but progress is outlined below.peer-reviewe