Non-volatility of ferroelectric SBT thin fims, at 75ºC

[ES] El estudio de la no volatilidad de una memoria FeRAM de tantalato de bismuto y estroncio, SrBi2Ta2O9 (SBT) en condiciones reales de uso, requiere la caracterización ferroeléctrica del material en forma de lámina delgada a temperaturas por encima del ambiente. Para ello se han depositado láminas de SBT mediante un método sol-gel, sobre substratos de Pt/TiO2/SiO2/Si(100), seleccionándose condensadores de área 5.10-4 cm-2. Basándonos en las medidas de la variación de la polarización con el tiempo (retención) realizadas a temperatura ambiente y a 75ºC, analizamos la viabilidad del material como una FeRAM en condiciones reales de uso.[EN] The study of the non-volatility of Strontium bismuth tantalate SrBi2Ta2O9 (SBT) FeRAM memory, at real operating conditions, requires the ferroelectric characterisation of the material, as a thin film, above the room temperature.As a result, it has been deposited SBT films by the sol-gel method, onto Pt/TiO2/SiO2/Si (100) substrates, using capacitors of 5 x 10–4 cm-2 .In this work, we analysed the viability of this material as a FeRAM memory in real operating conditions, as a result of the variation of the polarisation measurements with time (retention), performed at room temperature and 75ºC.Este trabajo ha sido realizado con el apoyo del proyecto de la CICYT MAT98-1068.Peer reviewe

Feasibility of (Pb, Ca)TiO3 thin films deposited on Pt/TiO2/SiO2/Si(100) for switching applications

[ES] Se han depositado láminas delgadas de (Pb,Ca)TiO3 sobre substratos de Pt/TiO2/SiO2/Si(100) por centrifugación, partiendo de soluciones sintetizadas por sol -gel. La concentración de las soluciones y el contenido de PbO se seleccionaron para minimizar las tensiones de las láminas cristalizadas y obtener la adecuada estequiometria. La cristalización mediante un calentamiento rápido (RTP), conduce a láminas con orientaciones preferentes [001]/[001], reducida capa interfacial ferroeléctrico-Pt y composición deseada. Los parámetros ferroeléctricos obtenidos muestran una mejora de las propiedades. Estas láminas presentan una fatiga y envejecimiento mucho más moderados que otros materiales alternativos depositados sobre substratos iguales, lo que permite considerar al método descrito como muy valioso para conseguir materiales susceptibles de emplear en aplicaciones de conmutación.[EN] (Pb,Ca)TiO3 ferroelectric thin films have been spin-coated on Pt/TiO2/SiO2/Si(100) substrates from sol-gel synthesized solutions. Selecting the solution concentrations and the excess of PbO content, stoichiometric composicion with reduced strains are obtained. Crystallization process by rapid thermal treatment (RTP) promote preferred orientations [001]/[100] resulting a thiner ferroelectric-platinum interface layer, which causes the improvement of fatigue and retain behaviour, despite the use of platinum electrodes. These experimental finds let to cosider the described methode of processing very convenient to prepare thin films of this composition to use on switching applications such as non volatil RAM memories.Peer reviewe

Synergetic Effect of Bimetallic Au-Ru/TiO2 Catalysts for CO and Methanol Complete Oxidation

It is well known that gold nanoparticles supported on metal oxides are active in various reactions of environmental importance.1 Particularly, supported Au nanoparticles is well known as very efficient catalysts for CO oxidation at low temperature.1 It is also possible to perform the oxidation of some volatile organic compounds (VOCs) such as light hydrocarbons and alcohols at room temperature. The most efficient and low-cost method for their abatement is the catalytic combustion to CO2 and H2O, preferentially at low temperatures. On the other hand, the preparation of bimetallic catalysts has been proposed as an alternative to improve the activity, stability and/or selectivity of gold catalysts. In this way, the addition of a second metal could modify the physicochemical and electronic properties of the first metal.2 Ruthenium-based catalysts have been studied in VOCs oxidation reaction, and in conjunction with gold, they exhibit an improvement in catalytic activity.Fil: Calzada, L.. Universidad Nacional Autónoma de México; MéxicoFil: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Delannoy, L.. Universite de Paris VI; FranciaFil: Louis, C.. Universite de Paris VI; FranciaFil: Ortalan, V.. Universidad Nacional Autónoma de México; MéxicoFil: Zanella, R.. Universidad Nacional Autónoma de México; MéxicoGold 2018ParisFranciaUniversité Pierre et Marie Curi

Alternatives to Animal Experimentation: Its Institutional Teaching and Scientific

Although it is desirable to replace scientific procedures with live animals by other methods that do not use them, the use of animals in scientific procedures should be restricted to those areas that benefit human, animal, and environmental health. The use of animals as experimental models of observation of biological phenomena has evolved with man, to this day. The use of animals for scientific or educational purposes should be considered only when there is no other alternative and it is governed by the principles of replacement, reduction, and refinement. The scientists should be sure that the information obtainable with the experiments is not yet available or that the protocol was designed taking into account animal protection considerations. The chosen methods must use the least number of animals; provide satisfactory results; use the species with the least ability to experience pain, suffering, anguish, and damage; and be optimal for the extrapolation of results to the target species such as humans. It will be fundamental to guarantee on a scientific and ethical basis that the use of an animal is subject to a careful evaluation regarding the scientific or educational validity

Superintegrability and higher order polynomial algebras II

In an earlier article, we presented a method to obtain integrals of motion and polynomial algebras for a class of two-dimensional superintegrable systems from creation and annihilation operators. We discuss the general case and present its polynomial algebra. We will show how this polynomial algebra can be directly realized as a deformed oscillator algebra. This particular algebraic structure allows to find the unitary representations and the corresponding energy spectrum. We apply this construction to a family of caged anisotropic oscillators. The method can be used to generate new superintegrable systems with higher order integrals. We obtain new superintegrable systems involving the fourth Painleve transcendent and present their integrals of motion and polynomial algebras.Comment: 11 page

Results of an international drug testing service for cryptomarket users

Introduction: User surveys indicate that expectations of higher drug purity are a key reason for cryptomarket use. In 2014-2015, Spain's NGO Energy Control conducted a 1-year pilot project to provide a testing service to cryptomarket drug users using the Transnational European Drug Information (TEDI) guidelines. In this paper, we present content and purity data from the trial. Methods: 219 samples were analyzed by gas chromatography associated with mass spectrometry (GC/MS). Users were asked to report what substance they allegedly purchased. Results: 40 different advertised substances were reported, although 77.6% were common recreational drugs (cocaine, MDMA, amphetamines, LSD, ketamine, cannabis). In 200 samples (91.3%), the main result of analysis matched the advertised substance. Where the advertised compound was detected, purity levels (m. ±. SD) were: cocaine 71.6. ±. 19.4%; MDMA (crystal) 88.3. ±. 1.4%; MDMA (pills) 133.3. ±. 38.4. mg; Amphetamine (speed) 51.3. ±. 33.9%; LSD 123.6. ±. 40.5. µg; Cannabis resin THC: 16.5. ±. 7.5% CBD: 3.4. ±. 1.5%; Ketamine 71.3. ±. 38.4%. 39.8% of cocaine samples contained the adulterant levamisole (11.6. ±. 8%). No adulterants were found in MDMA and LSD samples. Discussion: The largest collection of test results from drug samples delivered from cryptomarkets are reported in this study. Most substances contained the advertised ingredient and most samples were of high purity. The representativeness of these results is unknown

Possible Role of Nrf2 in Oxidative and Inflammatory Processes During Menopause

The increase in life expectancy leads to the possibility of development chronic diseases, from special physiological conditions as occurs in the menopause, which is defined as the permanent cessation of ovulation, marked by the end of menstruation. It has been related to decreased ovarian function that occurs around an age of 45 years. This event involves the reduction in estrogen production and may contribute to the development of chronic-degenerative diseases. Many diseases developed during menopause have been associated with oxidative stress, such as osteoporosis, hot flushes, cognitive impairment, insulin resistance, dry skin, obesity, and cardiovascular events. The knowledge about the participation of Nrf2 in diseases that occur during menopause is very limited. Here, only diseases such as osteoporosis, cardiovascular diseases and dry skin, which are present during menopause and its later stages have been described. The Nrf2 pathway involves the participation of PI3K/Akt, MAPK, and eNOS, which act as mediators for cytoprotection and antioxidation. Compounds such as equol, fitoestrogens, alkyl cathecols, or curcumin could be offered as options to antioxidant treatment, added the fact that they are present in fruits and vegetables which are rich in vitamins, minerals and calcium, thus including all the required nutrients for an adequate nutrition

Self-Reported Hidradenitis Suppurativa Severity: Is It Useful for Clinical Practice?

Introduction. Hidradenitis suppurativa (HS) is considered to be the most burdensome dermatosis, with a well-documented negative influence on quality of life (QoL). The patient’s perception of the disorder, assessed as the self-reported severity, has been used in other dermatoses but not in HS. The aim of this study was to evaluate the usefulness of self-reported HS severity in clinical practice. Methods. The study was performed on a group of 130 Spanish HS patients. HS severity was assessed for all the subjects. Hurley staging and patient self-reported severity were used. Moreover, QoL impairment was evaluated using the Dermatology Life Quality Index (DLQI) and the Hidradenitis Suppurativa Quality of Life 24 (HSQoL-24) questionnaire. Results. The severity of HS according to the Hurley staging was most commonly assessed as Hurley II (47.7%), indicating moderate disease, followed by severe disease (Hurley III, 26.9%) and mild disease (Hurley I, 25.4%). According to the patient self-reported HS severity, most of the patients reported having mild disease (76 patients, 58.5%), followed by moderate disease (31 patients, 23.8%). Only 23 patients (17.7%) assessed their disease as severe. Moreover, men reported mild disease significantly more frequently than women (70.9% and 49.3%, respectively; p = 0.014). The self-reported HS severity correlated positively with the effect of the disease on patient QoL assessed with DLQI (r = 0.288, p < 0.001). Likewise, a strong positive correlation was found between self-reported HS severity and QoL impairment assessed with HSQoL-24 (r = 0.404, p = 0.001). No statistically significant correlation between Hurley severity stage and DLQI or HSQoL-24 was found. Moreover, there were significant differences in both DLQI and HSQoL-24 total score between different self-reported HS severities. This was not seen for any of the QoL instruments or for Hurley severity staging. Conclusion. The results show that self-assessment severity may reflect patients’ subjective feelings more adequately than popular objective instruments, and there should be a place for its use in daily clinical practice

Sustainability in construction works: Reuse of sludge from tunnel boring in lime mortars

[EN]This study is based on reuse of sludge from tunnel boring for the manufacture of mortars with calcium hydroxide and their possible application in construction. Three samples have been tested with different percentages of sludge from tunnel boring obtaining high consistency. This percentage was used to produce two types of mortars, one with limestone-type aggregates and the other with siliceous-type material, which were then subjected to compression and flexural tests. The analysis shows that the use of these sludge, with calcium hydroxide and siliceous-type aggregates, helps to improve the mortars’ properties and increase their flexural strength to values above 4 MPa, which could be reused as a coating for underground work and road construction as long as its complies with the standard.Proyecto BATUCA 070/PC08/3-03.

Dynamic elements and kinetics: Most favorable conformations of peptides in solution with measurements and simulations

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared inJ. Chem. Phys. 151, 225102 (2019); doi: 10.1063/1.5131782 and may be found at https://aip.scitation.org/doi/10.1063/1.5131782.Small peptides in solution adopt a specific morphology as they function. It is of fundamental interest to examine the structural properties of these small biomolecules in solution and observe how they transition from one conformation to another and form functional structures. In this study, we have examined the structural properties of a simple dipeptide and a five-residue peptide with the application of far-UV circular dichroism (CD) spectroscopy as a function of temperature, fluorescence anisotropy, and all-atom molecular dynamics simulation. Analysis of the temperature dependent CD spectra shows that the simplest dipeptide N-acetyl-tryptophan-amide (NATA) adopts helical, beta sheet, and random coil conformations. At room temperature, NATA is found to have 5% alpha-helical, 37% beta sheet, and 58% random coil conformations. To our knowledge, this type of structural content in a simplest dipeptide has not been observed earlier. The pentapeptide (WK5) is found to have four major secondary structural elements with 8% 310 helix, 14% poly-L-proline II, 8% beta sheet, and 14% turns. A 56% unordered structural population is also present for WK5. The presence of a significant population of 310 helix in a simple pentapeptide is rarely observed. Fluorescence anisotropy decay (FAD) measurements yielded reorientation times of 45 ps for NATA and 120 ps for WK5. The fluorescence anisotropy decay measurements reveal the size differences between the two peptides, NATA and WK5, with possible contributions from differences in shape, interactions with the environment, and conformational dynamics. All-atom molecular dynamics simulations were used to model the structures and motions of these two systems in solution. The predicted structures sampled by both peptides qualitatively agree with the experimental findings. Kinetic modeling with optimal dimensionality reduction suggests that the slowest dynamic processes in the dipeptide involve sidechain transitions occurring on a 1 ns timescale. The kinetics in the pentapeptide monitors the formation of a distorted helical structure from an extended conformation on a timescale of 10 ns. Modeling of the fluorescence anisotropy decay is found to be in good agreement with the measured data and correlates with the main contributions of the measured reorientation times to individual conformers, which we define as dynamic elements. In NATA, the FAD can be well represented as a sum of contributions from representative conformers. This is not the case in WK5, where our analysis suggests the existence of coupling between conformational dynamics and global tumbling. The current study involving detailed experimental measurements and atomically detailed modeling reveals the existence of specific secondary structural elements and novel dynamical features even in the simplest peptide systems