On the interactions of melatonin/β-cyclodextrin inclusion complex: A novel approach combining efficient semiempirical extended tight-binding (xtb) results with ab initio methods

Melatonin (MT) is a molecule of paramount importance in all living organisms, due to its presence in many biological activities, such as circadian (sleep–wake cycle) and seasonal rhythms (reproduction, fattening, molting, etc.). Unfortunately, it suffers from poor solubility and, to be used as a drug, an appropriate transport vehicle has to be developed, in order to optimize its release in the human tissues. As a possible drug-delivery system, β-cyclodextrin (βCD) represents a promising scaffold which can encapsulate the melatonin, releasing when needed. In this work, we present a computational study supported by experimental IR spectra on inclusion MT/βCD complexes. The aim is to provide a robust, accurate and, at the same time, low-cost methodology to investigate these inclusion complexes both with static and dynamic simulations, in order to study the main actors that drive the interactions of melatonin with β-cyclodextrin and, therefore, to understand its release mechanism

On the interactions of melatonin/β-cyclodextrin inclusion complex: A novel approach combining efficient semiempirical extended tight-binding (xtb) results with ab initio methods

Melatonin (MT) is a molecule of paramount importance in all living organisms, due to its presence in many biological activities, such as circadian (sleep–wake cycle) and seasonal rhythms (reproduction, fattening, molting, etc.). Unfortunately, it suffers from poor solubility and, to be used as a drug, an appropriate transport vehicle has to be developed, in order to optimize its release in the human tissues. As a possible drug-delivery system, β-cyclodextrin (βCD) represents a promising scaffold which can encapsulate the melatonin, releasing when needed. In this work, we present a computational study supported by experimental IR spectra on inclusion MT/βCD complexes. The aim is to provide a robust, accurate and, at the same time, low-cost methodology to investigate these inclusion complexes both with static and dynamic simulations, in order to study the main actors that drive the interactions of melatonin with β-cyclodextrin and, therefore, to understand its release mechanism

Graft-Copolymerization of Acrylate Monomers onto Chitosan Induced by Gamma Radiation: Amphiphilic Polymers and Their Behavior at The Air-Water Interface

Graft polymerization induced by ionizing radiation is a powerful tool in materials science to modifying the physical properties of polymers. Chitosan is a biocompatible, biodegradable, antibacterial, and highly hydrophilic polysaccharide. In this work, we report the obtaining of amphiphilic polymers through graft polymerization of acrylic monomers (methyl acrylate, t-butyl acrylate, and hexyl acrylate) onto chitosan. The polymerization reaction was carried out by simultaneous irradiation of monomers and chitosan using a gamma radiation source of 60Co. The formation of Langmuir films of amphiphilic polymers was studied at the air-water interface through surface pressure versus main molecular area isotherms (Π-A) and hysteresis cycles of compression and decompression. Finally, it was analyzed the transferring of Langmuir films towards solid substrates to obtaining Langmuir-Blodgett films with potential application as an antibacterial coating. The microstructure of the Langmuir-Blodgett films was characterized by AFM microscopy observing a regular topography with roughness ranging between 0.53 and 0.6 μm

H(z)H(z) diagnostics on the nature of dark energy

The two dominant components of the cosmic budget today, pressureles matter and dark energy, may or may not be interacting with each other. Currently, both possibilities appear compatible with observational data. We propose several criteria based on the history of the Hubble factor that can help discern whether they are interacting and whether dark energy is phantom or quintessence in nature.Comment: 22 pages, 7 figures. Accepted for publication in IJMP

Emociones de los adolescentes internados en un centro de orientación juvenil. Córdoba – Colombia.

Objective. To identify the emotions that adolescents have about your stay in the Youth Guidance Center. Materials and methods. Using qualitative methods, consent was addressed was informed of the institution, professional caregivers and los16 hospitalized adolescents was applied by direct interview a semistructured instrument validated by experience and a field diary to record the relations of verbal responses with no verbal. Documented analyses using the 34 semantic expressions were grouped by similarity of content until 4 categories of interest to the study. Results. Teenagers have positive emotions regarding your stay; they consider this offer personal security, confidence and satisfaction of  their  daily  basic  needs.  In the category of interpersonal relationships with peers own personal-social sphere adolescent the presence of negative or unpleasurable emotions among those with personal history of emotional deprivation identified; on the contrary among those with affective previous history they showed better relationships with peers who come  to consider as part of their families. Conclusions. The internment of adolescents apparently alters the emotional dimension in the social field staff who have not had previous emotional ties.Objetivo. Identificar las emociones que tienen los adolescentes acerca de su internación en el Centro de Orientación Juvenil. Materiales y métodos. Utilizando metodologíascualitativas, seabordóprevioconsentimiento informado de la institución, de los cuidadores profesionales y de los 16 adolescentes internados se aplicó mediante entrevista directa un instrumento semiestructurado validado por la experiencia y un diario de campo para consignar las relaciones de las respuestas verbales con  las no verbales. Mediante análisis documentado las 34 expresiones semánticas se agruparon por semejanza de contenidos hasta obtener las 4 categorías de interés para el estudio. Resultados. Los adolescentes tienen emociones positivas con respecto a su internación, consideran que ésta le ofrece seguridad personal, confianza y satisfacción de sus necesidades básicas cotidianas. En la categoría de relaciones interpersonales con los pares propia de la esfera personal-social del adolescente se identificó la presencia de emociones negativas o displacenteras entre quienes tenían historia personal de carencias afectivas; por el contrario entre quienes tenían antecedentes afectivos previos manifestaron mejores relaciones con los pares a quienes llegan a considerar como parte de sus familias. Conclusiones. La internación de adolescentes puede alterar la dimensión emocional en el campo personal- social de quienes no han tenido vínculos afectivos previos

Datos sobre la vegetación silicícola de Andalucia I

The phytocenologic study about climatophilous vegetation series, which inhibat on siliceous soils in Málaga, Cádiz, Sevilla and Granada (Spain), has produced the identification of six vegetation series. It is described the following new syntaxa: Smilaco mauritanicae-Quercetum rotundifOliae quercetosum suberis,Teucrio baetici-Querceturn suberis quercetosum rotundifoliae and Cytiso baetici-Arbutetum unedonis.El estudio fitocenológico de las series de vegetación climatófilas que habitan sobre suelos silíceos de las provincias de Málaga, Cádiz, Sevilla y Granada ha dado como resultado la identificación de seis series.de vegetación. Se describen como nuevos los siguientes sintáxones: Smilaco mauritanicae-Quercetum rotundtfoliae quercetosum suberis, Teucrio baetici-Quercetum suberis quercetosum rotundifoliae y Cytiso baetici-Arbutetum unedonis

Gen-Z ambassadors: students supporting persons with Alzheimer’s disease and their caregivers in the Rio Grande Valley

Background: Youth participation in policy, research, education and community development initiatives is a right embedded in the United Nations Convention on the Rights of the Child (UNCRC, General Assembly, 1989). However, avenues for youth participation in health promotion and care remains limited. Our Ambassadors program prepares high-school students on the Texas-Mexico border to understand and empathize with persons with Alzheimer’s disease (PwAD) and to empower their family and caregivers, consummating the UNCRC in the service of transformative community change actions. Methods: Our long-term objective is youth participation, defined as practices that involve collaboration between students and various community stakeholders in AD. The initial phase of the program is the design of a curriculum for early high school students to develop the knowledge, skills and attitudes required for that participation. We used a cooperative strategy (a high school students-faculty collaborative), guided by empowerment and ecological theories to achieve optimal youth advancement in the context of the UNCRC social, health and cultural rights of children. Results: The GenZ Ambassadors curricular units were identified through an iterative process in which faculty documented their activities with youth and tested sessions ranging from the biological basis and clinical presentations of AD to family impact, principles of caregiving, youth as change agents, building intergenerational partnerships, and self-reflection exercises. Ambassadors selected settings and strategies designed to empower their peers and to transform communities by skill and confidence building. Discussion: The process implemented and content analysis revealed a variety of themes that benefited persons with AD and their caregivers in the Rio Grande Valley. Several strategies will be tested to generate interactive training materials and culturally and age-competent as well as delivery strategies, including peer-to-peer delivery

The sputum transcriptome better predicts COPD exacerbations after the withdrawal of inhaled corticosteroids than sputum eosinophils.

Introduction: Continuing inhaled corticosteroid (ICS) use does not benefit all patients with COPD, yet it is difficult to determine which patients may safely sustain ICS withdrawal. Although eosinophil levels can facilitate this decision, better biomarkers could improve personalised treatment decisions. Methods: We performed transcriptional profiling of sputum to explore the molecular biology and compared the predictive value of an unbiased gene signature versus sputum eosinophils for exacerbations after ICS withdrawal in COPD patients. RNA-sequencing data of induced sputum samples from 43 COPD patients were associated with the time to exacerbation after ICS withdrawal. Expression profiles of differentially expressed genes were summarised to create gene signatures. In addition, we built a Bayesian network model to determine coregulatory networks related to the onset of COPD exacerbations after ICS withdrawal. Results: In multivariate analyses, we identified a gene signature (LGALS12, ALOX15, CLC, IL1RL1, CD24, EMR4P) associated with the time to first exacerbation after ICS withdrawal. The addition of this gene signature to a multiple Cox regression model explained more variance of time to exacerbations compared to a model using sputum eosinophils. The gene signature correlated with sputum eosinophil as well as macrophage cell counts. The Bayesian network model identified three coregulatory gene networks as well as sex to be related to an early versus late/nonexacerbation phenotype. Conclusion: We identified a sputum gene expression signature that exhibited a higher predictive value for predicting COPD exacerbations after ICS withdrawal than sputum eosinophilia. Future studies should investigate the utility of this signature, which might enhance personalised ICS treatment in COPD patients

Unified Dark Matter models with fast transition

We investigate the general properties of Unified Dark Matter (UDM) fluid models where the pressure and the energy density are linked by a barotropic equation of state (EoS) $p = p(\rho)$ and the perturbations are adiabatic. The EoS is assumed to admit a future attractor that acts as an effective cosmological constant, while asymptotically in the past the pressure is negligible. UDM models of the dark sector are appealing because they evade the so-called "coincidence problem" and "predict" what can be interpreted as $w_{\rm DE} \approx -1$, but in general suffer the effects of a non-negligible Jeans scale that wreak havoc in the evolution of perturbations, causing a large Integrated Sachs-Wolfe effect and/or changing structure formation at small scales. Typically, observational constraints are violated, unless the parameters of the UDM model are tuned to make it indistinguishable from $\Lambda$CDM. Here we show how this problem can be avoided, studying in detail the functional form of the Jeans scale in adiabatic UDM perturbations and introducing a class of models with a fast transition between an early Einstein-de Sitter CDM-like era and a later $\Lambda$CDM-like phase. If the transition is fast enough, these models may exhibit satisfactory structure formation and CMB fluctuations. To consider a concrete case, we introduce a toy UDM model and show that it can predict CMB and matter power spectra that are in agreement with observations for a wide range of parameter values.Comment: 30 pages, 15 figures, JHEP3 style, typos corrected; it matches the published versio

Non-minimal Quintessence: Dynamics and coincidence problem

Brans--Dicke scalar--tensor theory provides a conformally coupling of the scalar field with gravity in Einstein's frame. This model is equivalent to an interacting quintessence in which dark matter is coupled to dark energy. This provides a natural mechanism to alleviate the coincidence problem. We investigate the dynamics of this model and show that it leads to comparable dark energy and dark matter densities today.Comment: To appear in Pramana Journal of Physics, 201