Interfacial tension behavior of binary and ternary mixtures of partially miscible Lennard-Jones fluids: a molecular dynamics simulation

By means of extensive equilibrium molecular dynamics simulations we have investigated, the behavior of the interfacial tension $\gamma$ of two immiscible symmetrical Lennard-Jones fluids. This quantity is studied as function of reduced temperature $T^{*}={{k_{_B} T}\over \epsilon}$ in the range $0.6 \leq T^{*} \leq 3.0$. We find that, unlike the monotonic decay obtained for the liquid-vapor interfacial tension, for the liquid-liquid interface, $\gamma (T)$ has a maximum at a specific temperature. We also investigate the effect that surfactant-like particles has on the thermodynamic as well as the structural properties of the liquid-liquid interface. It is found that $\gamma$ decays monotonically as the concentration of the surfactant-like particles increases.Comment: LaTeX-Revtex file with 7 encapsulated postscript figures. Accepted for publication in Journal of Chemical Physic

Disclination lines at homogeneous and heterogeneous colloids immersed in a chiral liquid crystal

In the present work we perform Monte Carlo simulations in the isothermal-isobaric ensemble to study defect topologies formed in a cholesteric liquid crystal due to the presence of a spherical colloidal particle. Topological defects arise because of the competition between anchoring at the colloidal surface and the local director. We consider homogeneous colloids with either local homeotropic or planar anchoring to validate our model by comparison with earlier lattice Boltzmann studies. Furthermore, we perform simulations of a colloid in a twisted nematic cell and discuss the difference between induced and intrinsic chirality on the formation of topological defects. We present a simple geometrical argument capable of describing the complex three-dimensional topology of disclination lines evolving near the surface of the colloid. The presence of a Janus colloid in a cholesteric host fluid reveals a rich variety of defect structures. Using the Frank free energy we analyze these defects quantitatively indicating a preferred orientation of the Janus colloid relative to the cholesteric helix.DFG, GRK 1524, Self-Assembled Soft-Matter Nanostructures at Interface

Analysis and evaluation of the operational characteristics of a new photodynamic therapy device

One of the key aspects of photodynamic therapy is the light source that is used to irradiate the lesion to be treated. The devices used must ensure that their emission spectrum matches the absorption spectrum of the photosensitizer, so that treatment radiation is delivered only on the target area, without irradiating healthy tissue at superficial or deep levels. Irradiance values must be adequate in order to avoid thermal damage, exceed the oxygen replenishment rate and avoid long treatment times. Furthermore, the device should be user-friendly, inexpensive, and able to be adapted to different photosensitizers. We have developed an easy-to-use and highly customizable device based on LED technology. Its innovative geometric design allows radiation to be delivered to a small treatment surface, since the LEDs are arranged in three arms, the configuration of which directs their radiation on the treatment point. Different high-power color LEDs are disposed on the arms, and can be independently selected based on the most effective wavelengths for exciting the different photodynamic therapy photosensitizers. We have tested the prototype in 5 different patients (1 actinic keratose, 1 actinic cheilitis, 1 superficial basal cell carcinoma and 2 Bowen's disease) and after 1-2 sessions of total cumulative dose of 25-50 J / cm2, 100% clearance of lesions were obtained. Our device can be used by any professional in the field, whether for medical or research purposes. It facilitates the development of treatment protocols and trials with different photosensitizers

Plan de mejoramiento del proceso de selección de personal en el Hotel Rancho Regis S.A.S de la ciudad de Valledupar

La industria hotelera, como parte esencial del sector turismo a nivel global, se esfuerza continuamente por brindar experiencias excepcionales a sus huéspedes. Para alcanzar este objetivo, la selección adecuada del personal que conforma el equipo de un hotel se convierte en un factor crítico que influye directamente en la calidad del servicio, la satisfacción del cliente y la competitividad del establecimiento. Sin embargo, a nivel global, esta selección de personal enfrenta una serie de falencias que trascienden fronteras geográficas y afectan a numerosos hoteles en todo el mundo. La relevancia de este estudio radica en su enfoque global, reconociendo que la industria hotelera opera en un contexto internacional, nacional y local, que las problemáticas de selección de personal no conocen fronteras. A través de un análisis y la aplicación de enfoques innovadores en la gestión de recursos humanos, este trabajo busca ofrecer soluciones y recomendaciones prácticas que beneficien tanto a hoteles individuales como a la industria hotelera en su conjunto.The hotel industry, as an essential part of the global tourism sector, continuously strives to provide exceptional experiences to its guests. To achieve this goal, the proper selection of the personnel comprising a hotel's team becomes a critical factor that directly influences service quality, customer satisfaction, and the establishment's competitiveness. However, at a global level, this personnel selection faces a series of shortcomings that transcend geographical borders and affect numerous hotels worldwide. The relevance of this study lies in its global approach, recognizing that the hotel industry operates in an international, national, and local context, and that personnel selection issues do not recognize boundaries. Through analysis and the application of innovative approaches in human resources management, this work aims to provide practical solutions and recommendations that benefit both individual hotels and the hotel industry as a whole

Low cost system based on infrared technology for water management

Water is an essential element in the life of the human being for which its conservation and good use is necessary, in this work we make a proposal for the development of a low-cost system for water management in order to save on Its consumption, using infrared technology, the results provide a mechanism that can be replicated and at different scales, by the use of commonly used devices.Campus At

Gamma radiation as a recycling tool for waste materials used in concrete

Over the course of the last 50 years, a large number of major technological advances have contributed to the development of higher-strength, high-performance materials that provide excellent benefits. Nevertheless, in most cases, after a very short useful life, these products become waste material and contribute to environmental degra‐ dation. This situation has created an environmental crisis that has reached global proportions. In efforts to combat this issue and to promote sustainable development and reduce environmental pollution, some investigations have focused on recycling using innovative and clean technologies, such as gamma radiation, as an alternative to conventional mechanical and chemical recycling procedures. In this context, the reuse and recycling of waste materials and the use of gamma radiation are useful tools for improving the mechanical properties of concrete; for example, the compressive strength and modulus of elasticity are improved by the addition of waste particles and application of gamma radiation. In this chapter, we propose the use of gamma radiation as a method for modifying waste materials; for instance, polyethylene terephthalate plastic bottles, automotive tire rubber, and the cellulose in Tetra Pak containers, and their reuse to enhance the properties of concrete

Consolidar el modelo de negocio en el lienzo CANVAS

En el presente trabajo trabajamos un modelo de negocios CANVAS reestructurado, presentándolo de forma Gráfica y Escrita; con el cual se busca hacer “Un modelo CANVAS que permita detectar sistemáticamente elementos que generan valor en un proyecto emprendedor” por lo que utilizamos las estrategias y propuesta de valor desarrolladas en actividades anteriores para culminar nuestra idea de negocios y presentar la propuesta del proyecto de emprendimiento social en un Pitch elaborado en formato digital como se observará a continuación.In the present work we work on a restructured CANVAS business model, presenting it graphically and in writing; which seeks to make "A CANVAS model that allows systematically detect elements that generate value in an entrepreneurial project" so we use the strategies and value proposition developed in previous activities to complete our business idea and present the project proposal of Social entrepreneurship in a Pitc

Lymphocyte Profile and Immune Checkpoint Expression in Drug-Induced Liver Injury: An Immunophenotyping Study

The identification of specific HLA risk alleles in drug-induced liver injury (DILI) points toward an important role of the adaptive immune system in DILI development. In this study, we aimed to corroborate the role of an adaptive immune response in DILI through immunophenotyping of leukocyte populations and immune checkpoint expressions. Blood samples were collected from adjudicated DILI (n = 12), acute viral hepatitis (VH; n = 13), acute autoimmune hepatitis (AIH; n = 9), and acute liver injury of unknown etiology (n = 15) at day 1 (recognition), day 7, and day >30. Blood samples from patients with nonalcoholic fatty liver disease (NAFLD; n = 20) and healthy liver controls (HLCs; n = 54) were extracted at one time point. Leukocyte populations and immune checkpoint expressions were determined based on cell surface receptors, except for CTLA-4 that was determined intracellularly, using flow cytometry. At recognition, DILI demonstrated significantly higher levels of activated helper T-cell (P < 0.0001), activated cytotoxic T-cells (P = 0.0003), Th1 (P = 0.0358), intracellular CTLA-4 level in helper T-cells (P = 0.0192), and PD-L1 presenting monocytes (P = 0.0452) than HLC. These levels approached those of HLC over time. No significant differences were found between DILI and VH. However, DILI presented higher level of activated helper T-cells and CTLA-4 than NAFLD and lower PD-L1 level than AIH. Our findings suggest that an adaptive immune response is involved in DILI in which activated CD4+ and CD8+ play an important role. Increased expression of negative immune checkpoints is likely the effect of peripheral tolerance regulation.The present study has been supported by grants of Instituto de Salud Carlos III cofounded by Fondo Europeo de Desarrollo Regional – FEDER (contract numbers: PI19/00883, PI16/01748, P18-RT-3364-2020, and PT20/000127). CIBERehd and Plataforma ISCiii Ensayos Clínicos are funded by Instituto de Salud Carlos III. Funding for open access charge: Universidad de Málaga/CBUA. The funding sources had no involvement in the study design; in the collection, analysis, and interpretation of data; in the writing of the report, or in the decision to submit the manuscript for publication

Los bancos centrales y el crecimiento de la productividad en Latinoamérica en el siglo XXI: un enfoque macroeconómico de economía institucional

El presente trabajo de investigación analiza el impacto de la efectividad de la política monetaria en el control de la inflación, y de su interacción con la institucionalidad en general, sobre el crecimiento de la productividad total de los factores. Las instituciones son entendidas como el conjunto de reglas sociales que las personas consideran y cumplen. Un efecto positivo de la efectividad de la política monetaria sobre la productividad implicaría que no se cumple la hipótesis de la neutralidad del dinero. Dicho efecto podría depender del grado de institucionalidad en el país. En ese sentido, se analizan los datos de productividad, inflación e instituciones para las cinco economías más importantes de América Latina cuyos bancos centrales tienen metas de inflación, para el período 2000-2019 (pre Covid-19)

Características clínico-epidemiológicas de los pacientes amputados ingresados a la unidad de pie diabético del Hospital Abel Gilbert Pontón, Ecuador

Objetivo: Evaluar las caracter&iacute;sticas cl&iacute;nico epidemiol&oacute;gicasde los pacientes amputados ingresados a la unidad de piediab&eacute;tico del Hospital Abel Gilbert Pont&oacute;n, Ecuador.Materiales y m&eacute;todos: Se trat&oacute; de un estudio descriptivo yretrospectivo en pacientes mayores de 25 a&ntilde;os ingresadosa la unidad de pie diab&eacute;tico del Hospital de Especialidadesde Guayaquil Dr. Abel Gilbert Pont&oacute;n que hayan sido sometidosa amputaci&oacute;n, relacionada a diabetes mellitus, enel periodo comprendido entre enero a diciembre de 2014.Se emplearon los registros cl&iacute;nicos de las historias que seencuentran en el departamento de datos y estad&iacute;sticas delmencionado hospital.Resultados: De los 147 pacientes evaluados, el 63% (n=93)fueron del sexo masculino, el grupo etario m&aacute;s frecuente fueel de 50-70 a&ntilde;os (37%; n=54), la mayor&iacute;a s&oacute;lo ten&iacute;a estudiosde educaci&oacute;n primaria (69%; n=102) y proced&iacute;an de zonasurbanas (87%; n=125), la comorbilidad m&aacute;s frecuente fue lahipertensi&oacute;n arterial (44,9%; n=66), la infecci&oacute;n de piel y partesblandas fue la causa de ingreso m&aacute;s prevalente (49%;n=72), mientras que un 69% (n=101) ten&iacute;a m&aacute;s de 10 a&ntilde;oscon la DM y la amputaci&oacute;n suprarotuliana fue el procedimientom&aacute;s utilizado (52%; n=76).Conclusi&oacute;n: Existe una alta frecuencia de pacientes conpie diab&eacute;tico admitidos al Hospital Abel Gilbert Pont&oacute;n queameritan amputaci&oacute;n, cuyos factores m&aacute;s prevalentes fueronel sexo masculino, la edad entre 50-70 a&ntilde;os, el bajo estatuseducativo, la procedencia urbana, la coexistencia de hipertensi&oacute;narterial, la infecci&oacute;n como causa de ingreso m&aacute;s importantey el tiempo de evoluci&oacute;n de la DM mayor de 10 a&ntilde;o