Current profiles and AC losses of a superconducting strip with elliptic cross-section in perpendicular magnetic field

The case of a hard type II superconductor in the form of strip with elliptic cross-section when placed in transverse magnetic field is studied. We approach the problem in two steps, both based on the critical-state model. First we calculate numerically the penetrated current profiles that ensure complete shielding in the interior, without assuming an a priori form for the profiles. In the second step we introduce an analytical approximation that asumes that the current profiles are ellipses. Expressions linking the sample magnetization to the applied field are derived covering the whole range of applied fields. The theoretical predictions are tested by the comparison with experimental data for the imaginary part of AC susceptibility.Comment: 12 pages; 3 figure

Constraints on dark matter particles from theory, galaxy observations and N-body simulations

Mass bounds on dark matter (DM) candidates are obtained for particles decoupling in or out of equilibrium with {\bf arbitrary} isotropic and homogeneous distribution functions. A coarse grained Liouville invariant primordial phase space density $\mathcal D$ is introduced. Combining its value with recent photometric and kinematic data on dwarf spheroidal satellite galaxies in the Milky Way (dShps), the DM density today and $N$-body simulations, yields upper and lower bounds on the mass, primordial phase space densities and velocity dispersion of the DM candidates. The mass of the DM particles is bound in the few keV range. If chemical freeze out occurs before thermal decoupling, light bosonic particles can Bose-condense. Such Bose-Einstein {\it condensate} is studied as a dark matter candidate. Depending on the relation between the critical($T_c$)and decoupling($T_d$)temperatures, a BEC light relic could act as CDM but the decoupling scale must be {\it higher} than the electroweak scale. The condensate tightens the upper bound on the particle's mass. Non-equilibrium scenarios that describe particle production and partial thermalization, sterile neutrinos produced out of equilibrium and other DM models are analyzed in detail obtaining bounds on their mass, primordial phase space density and velocity dispersion. Light thermal relics with $m \sim \mathrm{few} \mathrm{keV}$ and sterile neutrinos lead to a primordial phase space density compatible with {\bf cored} dShps and disfavor cusped satellites. Light Bose condensed DM candidates yield phase space densities consistent with {\bf cores} and if $T_c\gg T_d$ also with cusps. Phase space density bounds from N-body simulations suggest a potential tension for WIMPS with $m \sim 100 \mathrm{GeV},T_d \sim 10 \mathrm{MeV}$.Comment: 27 pages 8 figures. Version to appear in Phys. Rev.

Combination of polymeric superplasticizers, water repellents and pozzolanic agents to improve air lime-based grouts for historic masonry repair

This paper presents the experimental procedure to develop air lime-based injection grouts including polymeric superplasticizers, a water repellent agent and pozzolanic agents as additives. Research focuses on the development of grouts to improve various characteristics simultaneously combining different additions and admixtures. Aiming to improve the injectability of the grouts, in this study different polymeric superplasticizers were added, namely polycarboxylated-ether derivative (PCE), polynaphthalene sulfonate (PNS) and condensate of melamine-formaldehyde sulfonate (SMFC). Sodium oleate was also used as a water repellent agent to reduce the water absorption. The enhancement of the strength and setting time was intended by using microsilica and metakaolin as pozzolanic mineral additions. Compatibility between the different admixtures and action mechanism of the different polymers were studied by means of zeta potential and adsorption isotherms measurements. Diverse grout mixtures were produced and investigated assessing their injectability, fluidity, stability, compressive strength, hydrophobicity and durability. This research leads to several suitable mixtures produced by using more than one component to enhance efficiency and to provide better performance of grouts. According to the results, the grout composed of air lime, metakaolin, sodium oleate and PCE was found the most effective composition improving the mechanical strength, injectability and hydrophobicity

Perivellosa disease massive fibrin deposition, association with Down syndrome: case report and literature review

The disease perivellosa massive fibrin deposition (MPFD), is a condition characterized by uncontrolled mainly fibrin deposition intervillous space. The incidence worldwide is 0.028% per 1000 live births, there is only one case report where this condition is associated with trisomy 21, in our country there are no reports of this disease. The MPFD has high morbidity, obstetric mortality, recurrence, as well as neurodevelopmental significance of newborns. The etiology until the moment is unknown, difficult diagnosis and management for the obstetrician. The aim is to report MPFD association with trisomy 21 (T21) and a review of the medical literature regarding this condition

Bioenergetic and Autophagic Characterization of Skin Fibroblasts from C9orf72 Patients.

The objective of this study is to describe the alterations occurring during the neurodegenerative process in skin fibroblast cultures from C9orf72 patients. We characterized the oxidative stress, autophagy flux, small ubiquitin-related protein SUMO2/3 levels as well as the mitochondrial function in skin fibroblast cultures from C9orf72 patients. All metabolic and bioenergetic findings were further correlated with gene expression data obtained from RNA sequencing analysis. Fibroblasts from C9orf72 patients showed a 30% reduced expression of C9orf72, ~3-fold increased levels of oxidative stress and impaired mitochondrial function obtained by measuring the enzymatic activities of mitochondrial respiratory chain complexes, specifically of complex III activity. Furthermore, the results also reveal that C9orf72 patients showed an accumulation of p62 protein levels, suggesting the alteration of the autophagy process, and significantly higher protein levels of SUMO2/3 (p = 0.03). Our results provide new data reinforcing that C9orf72 cells suffer from elevated oxidative damage to biomolecules and organelles and from increased protein loads, leading to insufficient autophagy and an increase in SUMOylation processes

Zein nanoparticles for oral folic acid delivery

The aim of this work was to prepare and evaluate the capability of zein nanoparticles for oral drug delivery. More particularly, in this work, the ability of these nanoparticles to improve the oral bioavailability of folic acid is reported. The nanoparticles were prepared by a desolvation process, followed by purification via ultrafiltration and drying in a spray-drier apparatus. The resulting nanoparticles displayed a mean size close to 200 nm with negative zeta potential and a payload of 54 μg folic acid per mg nanoparticle. From the in vitro release studies, it was observed that folic acid was only released from nanoparticles in simulated intestinal conditions. In vivo biodistribution studies,with radiolabelled or fluorescently marked nanoparticles, revealed that nanoparticles remained within the gut and were capable of interacting with the protective mucus layer of the jejunum. For the pharmacokinetic study, folic acid was orally administered to rats as a single dose of 1 mg/kg.The relatively oral bioavailability of folic acid, when encapsulated in zein nanoparticles, was around 70%: two-times higher than the value obtained with an aqueous solution of the vitamin. This fact might be explained by the mucoadhesive properties of these nanoparticles

Morteros de relleno para restauración de patrimonio cultural, con base cal con adición puzolánica y diversos aditivos

Los morteros de relleno o inyección, especialmente destinados a reparación de cavidades y defectos de albañilería, deben fluir adecuadamente en estado fresco y combinar resistencia y durabilidad. Para conseguir algunas de estas características pueden utilizarse aditivos químicos: superplastificantes, para mejorar la fluidez; adiciones puzolánicas, para conseguir resistencias adecuadas en ambientes con limitado acceso de CO2 y una mejora de la durabilidad; e hidrofugantes, de manera que, sin perjudicar la permeabilidad de estos materiales al vapor de agua, se evite la penetración de agua por capilaridad mejorando la durabilidad. Sin embargo, en la mayor parte de los casos, toda la información disponible se circunscribe al efecto de un único aditivo, sin contemplar el posible efecto conjunto o incluso sinérgico de las combinaciones más interesantes de dos o más aditivos y/o adiciones puzolánicas. El estudio de las sinergias entre estos componentes ofrece posibilidades muy interesantes de avance científico-técnico. Precisamente este es el objetivo del trabajo: diseño de nuevos morteros de inyección de cal que puedan ser utilizados para la restauración del Patrimonio Edificado mediante combinación adecuada de aditivos superplastificantes (éteres de policarboxilato, condensados de naftaleno-formaldehído, sulfonato de melamina y ácido poliacrílico), hidrofugante (oleato sódico) y adiciones minerales puzolánicas (microsílice y metacaolín)