Temperature dependence of surface stress across an order-disorder transition: p(1x2)O/W(110)

Strain relaxations of a p(1x2) ordered oxygen layer on W(110) are measured as a function of temperature across the disordering transition using low-energy electron diffraction. The measured strains approach values of 0.027 in the [1-10] and -0.053 in the [001] direction. On the basis of the measured strain relaxations, we give quantitative information on temperature-dependent surface stress using the results of ab initio calculations. From the surface formation energy for different strains, determined by first-principles calculations, we estimate that surface stress changes from -1.1 for the ordered phase to -0.2N/m for the disordered one along [1-10], and from 5.1 to 3.4 N/m along [001]. Moreover, our observation that the strains scale inversely with domain size confirms that the strain relaxation takes place at the domain boundaries.Comment: 8 pages, 5 figure

Modelos de programación estocásticos para el diseño de redes logísticas

En la cadena de Abastecimiento, la gestión logística es la etapa de planifcación, en la cual, la distribución física de productos, programación y apoyo los procesos de fabricación, la planeación y las actividades se relacionan con los productos terminados y materiales determinados y organizados para obtener el mejor resultados. El problema de diseñar una red logística, en muchos casos, se asocia a la formulación correcta del modelo en función del contexto, desde el desarrollo de los sistemas hasta la inclusión de todas las posibles variables que pueden afectar los procesos. De todo esto, depende el éxito de su construcción y los resultados veraces. Este trabajo muestra el diseño de una red logística y la aplicación de restricciones estocásticas en su programación, las variables aleatorias cambian todo el tiempo e incluso la variabilidad natural asociada a los procesos, esto con el fn de responder efectivamente la realidad de los sistemas dentro de las organizacionesAbstract: In a supply chain, logistical management is the planning stage, in which, the physical distribution of products, scheduling and supporting manufacturing operations, planning and activities are related with the fnal products and certain materials are organized for geting the wished results. The problem of designing a logistical network, in many cases, is associated to the correct formulation of the model according to the context in which, the systems develops; from the incursion of all the possible variables that can afect the processes, will depends the success of the said model and truthful results. This paper shows the design of a logistical network and the introduction of stochastic constrains in its programming, the random variables that change through the time with the natural variability associated to the processes, this with the purpose of responding more precisely to the reality inherent to the systems inside the organizations

Stress engineering at the nanometer scale: Two-component adlayer stripes

Spontaneously formed equilibrium nanopatterns with long-range order are widely observed in a variety of systems, but their pronounced temperature dependence remains an impediment to maintain such patterns away from the temperature of formation. Here, we report on a highly ordered stress-induced stripe pattern in a two-component, Pd-O, adsorbate monolayer on W(110), produced at high temperature and identically preserved at lower temperatures. The pattern shows a tunable period (down to 16 nm) and orientation, as predicted by a continuum model theory along with the surface stress and its anisotropy found in our DFT calculations. The control over thermal fluctuations in the stripe formation process is based on the breaking/restoring of ergodicity in a high-density lattice gas with long-range interactions upon turning off/on particle exchange with a heat bath.Comment: 6 pages, 4 figure

Cronología de la erupción dentaria en caninos superiores e inferiores

Objectives: To establish the chronological sequence of the dental eruption in canines, carrying out various investigations in different studies that indicate, according to their analyzes, that there is a direct relationship with the factors that cause their eruption to be altered. Methods: A bibliographic review was carried out from October to December 2020, using the following search strategy in the database: Scielo, Repository, Medical journals, within which 22 articles related to the subject were considered, taking into account that 90% of the publications and bibliographic reviews were from 2010-2020. Results: In different studies a close relationship was found in the different factors that tend to cause the advance or delay in its appearance. That is why it is necessary to consider investigating the biological factors that can affect the development of the tooth bud. Conclusion: All the information that has been obtained in this investigation, we conclude that the order of eruption of the mentioned teeth, whether they are upper and lower canines, is affected and is influenced by components such as malnutrition, geographical environment, climate, race, factor environmental, sex and age.Objetivos: Establecer la secuencia cronología de la erupción dentaria en caninos, realizando diversas investigaciones en diferentes estudios que indican según sus análisis que existe relación directa con los factores que hacen que su erupción se vea alterada. Métodos: Se realizó una revisión bibliográfica a partir de octubre hasta diciembre del 2020, empleando la siguiente estrategia de búsqueda en la base de datos: Scielo, Repositorio, Revistas médicas dentro de los cuales se consideró 22 artículos relacionados con el tema, tomando en cuenta que el 90% de las publicaciones y revisiones bibliográficas fueron del 2010 – 2020. Resultados: En diferentes estudios se encontraron una estrecha relación en los diferentes factores que tienden a provocar el adelanto o retraso en su aparición. Es por ello que se necesita considerar investigar los factores biológicos que pueden afectar el desarrollo del brote de los dientes. Conclusión: Toda la información que se ha podido obtener en esta investigación, concluimos que el orden de erupción de los dientes mencionados, sean caninos superiores e inferiores se ve afectada e influyen los componentes como la desnutrición, el medio geográfico, el clima, la raza, factor ambiental, sexo y edad

For which infants with viral bronchiolitis could it be deemed appropriate to use albuterol, at least on a therapeutic trial basis?

Although there is increasing evidence showing that infants with viral bronchiolitis exhibit a high degree of heterogeneity, a core uncertainty shared by many clinicians is with regard to understanding which patients are most likely to benefit from bronchodilators such as albuterol. Based on our review, we concluded that older infants with rhinovirus (RV) bronchiolitis, especially those with a nasopharyngeal microbiome dominated by Haemophilus influenzae; those affected during nonpeak months or during non-respiratory syncytial virus (RSV) predominant months; those with wheezing at presentation; those with clinical characteristics such as atopic dermatitis or a family history of asthma in a first-degree relative; and those infants infected with RSV genotypes ON1 and BA, have the greatest likelihood of benefiting from albuterol. Presently, this patient profile could serve as the basis for rational albuterol administration in patients with viral bronchiolitis, at least on a therapeutic trial basis, and it could also be the starting point for future targeted randomized clinical trials (RCTs) on the use of albuterol among a subset of infants with bronchiolitis

Heterologous expression of the yeast Tpo1p or Pdr5p membrane transporters in Arabidopsis confers plant xenobiotic tolerance

This deposit is composed by the main article plus the supplementary materials of the publication.Soil contamination is a major hindrance for plant growth and development. The lack of effective strategies to remove chemicals released into the environment has raised the need to increase plant resilience to soil pollutants. Here, we investigated the ability of two Saccharomyces cerevisiae plasma-membrane transporters, the Major Facilitator Superfamily (MFS) member Tpo1p and the ATP-Binding Cassette (ABC) protein Pdr5p, to confer Multiple Drug Resistance (MDR) in Arabidopsis thaliana. Transgenic plants expressing either of the yeast transporters were undistinguishable from the wild type under control conditions, but displayed tolerance when challenged with the herbicides 2,4-D and barban. Plants expressing ScTPO1 were also more resistant to the herbicides alachlor and metolachlor as well as to the fungicide mancozeb and the Co(2+), Cu(2+), Ni(2+), Al(3+) and Cd(2+) cations, while ScPDR5-expressing plants exhibited tolerance to cycloheximide. Yeast mutants lacking Tpo1p or Pdr5p showed increased sensitivity to most of the agents tested in plants. Our results demonstrate that the S. cerevisiae Tpo1p and Pdr5p transporters are able to mediate resistance to a broad range of compounds of agricultural interest in yeast as well as in Arabidopsis, underscoring their potential in future biotechnological applications.Fundação para a Ciência e a Tecnologia grants: (EXPL/AGR-PRO/1013/2013, PTDC/BIA-PLA/1084/2014, SFRH/BPD/44640/2008, SFRH/BPD/81221/2011, PD/BD/105735/2014, PD/00133/2012, SFRH/BD/92552/2013, UID/BIO/04565/2013, UID/Multi/04551/2013). Programa Operacional Regional de Lisboa 2020 grant: (Project N. 007317).info:eu-repo/semantics/publishedVersio

Utilizing volatile organic compounds for early detection of Fusarium circinatum

Acknowledgements This study was financially supported by The Swedish Research Council Formas, Grant #2018-00966, Crafoordska stiftelsen Grant #20200631, Carl Tryggers Stiftelse för Vetenskaplig Forskning Grant 18:67, The Royal Swedish Academy of Agriculture and Forestry, Stiftelsen fonden för skogsvetenskaplig forskning, Erasmus+ Staff mobility grant, Anna-Britta & Vadim Söderströms resestipendium and NordGen Forest SNS scholarships. J.N.S. was supported by The European Union’s Horizon Europe research and innovation programme under the MSCA agreement No 101068728. Thanks to dr. R.R. Vetukuri for providing F. graminearum, to the staff of Laboratorio de Técnicas Instrumentales, Universidad de Valladolid, for providing access to lab facilities and to J-E. Englund for assistance in making the experimental design. Funding Open access funding provided by Swedish University of Agricultural Sciences.Peer reviewedPublisher PD

Finite voltage shot noise in normal-metal - superconductor junctions

We express the low-frequency shot noise in a disordered normal-metal - superconductor (NS) junction at finite (subgap) voltage in terms of the normal scattering amplitudes and the Andreev reflection amplitude. In the multichannel limit, the conductance exhibits resonances which are accompanied by an enhancement of the (differential) shot noise. In the study of multichannel single and double barrier junctions we discuss the noise properties of coherent transport at low versus high voltage with respect to the Andreev level spacing.Comment: 6 pages, Latex, 2 eps-figures, to be published in PRB, Appendix on Bogoliubov equation

Chemical recycling of plastics assisted by microwave multi-frequency heating

Handling plastic waste through recycling allows extending the life of polymeric materials, avoiding recurrence to incineration or landfilling. In contrast with traditional mechanical recycling technologies, chemical recycling enables the obtention of the virgin monomers by means of depolymerisation to create new polymers with the same mechanical and thermal properties as the originals. Research presented in this paper is part of the polynSPIRE project (Horizon 2020 European funding programme) and develops and scales-up a heated reactor to carry out the depolymerisation of polyamide-6 (PA6), polyamide-6, 6 (PA66) and polyurethane (PU) using microwave (MW) technology as the heating source. The purpose is to design and optimize a MW reactor using up to eight ports emitting electromagnetic waves. Finite element method (FEM) simulation and optimisation are used to design the reactor, considering as parameters the data obtained from experimental dielectric testing and lab-scale characterisation of the processes and materials studied. Two different COMSOL Multiphysics modules are involved in this work: Radio Frequency (RF) and Chemical Reaction Engineering (RE), to simulate the reactor cavity using two frequency levels (915 MHz and 2.45 GHz) with a power level of 46 kW, and the chemical depolymerisation process, respectively. A sensitivity study has been performed on key parameters such as the frequency, the number of ports, and position inside the reactor to consolidate the final design. It is expected that these results assist in the design and scale-up of microwave technology for the chemical recycling of plastics, and for the large-scale deployment of this sustainable recovery alternative. © 2021 The Author