Tailoring Organic-Organic Poly(vinylpyrrolidone) Microparticles and Fibers with Multiwalled Carbon Nanotubes for Reinforced Composites

Polymeric-based microparticles and fibers are tailorable for a wide range of common industrial and biomedical applications, while multiwalled carbon nanotubes (MWCNTs) are among the most useful macromolecules based on their outstanding electronic, mechanical, and optical properties at the nanoscale. If one combines these nanostructures with various polymeric precursors, their range of potential applications becomes even greater. One of the simplest and most affordable methods for fabricating micro- and nanostructures is electrospinning. Herein we demonstrate how MWCNTs may be used to produce tailor-made organic-organic poly(vinylpyrrolidone) (PVP) microparticles and fibers via electrospinning by studying their structural, vibrational, rheological, and mechanical properties' dependence on their solvent (ethanol (EtOH) or dimethylformamide (DMF)) and resulting morphology. Specifically, we find clear differences in morphologies from perfectly spherical and isolated microparticles to fibers mats, or a combination of fibers with entangled beads, with solvent type and concentration. On the basis of our findings, we propose that the mechanism governing the shape and size of the particles is a competition between the solvent's surface tension, dielectric constant, and viscoelastic properties. We show, based on both our experimental results and density functional theory (DFT) calculations, that OH functionalization of the MWCNTs is essential for achieving high PVP coverages and promoting the stability of the resulting PVP/MWCNT nanocomposite. Finally, by fabricating PVP/MWCNT fiber mats, we demonstrate that low concentrations (0.01-0.1 wt %) of MWCNTs led to a qualitative improvement (â250%) in the resulting mechanical properties, i.e., a reinforced composite. These results show how by controlling the solvent's dielectric constant, surface tension, and polymer concentration, one may produce tailor-made polymeric nanomaterials in combination with other organic/inorganic nanoparticles, i.e., silver, gold, or carbon allotropes, for next-generation applications

Algunos signos fisiológicos del síndrome de desgaste profesional en docentes de la Universidad de Panamá, campus central

The burnout syndrome (BS) is a group of symptoms and signs produced by chronic stress in those professionals devoted to prolonged and intense care to their dependants. The BS is concentrated in three aspects: emotional exhaustion (EE), depersonalization (DP) and personal accomplishment (PA). The main objective is to determine the level of burnout and relate it to social-demographic variables and also estimate physiological variations related to BS degree. Design: ex post facto retrospective. Information related to social demographics, working status and BS test was obtained trough a random sampling through written questions gathering. Pearson correlation and T test were used for the statistical analysis of a sample of n=51 (31 males, 20 female); age: 51±8.22 yrs.; 64% of them with more than 20 years of experience in teaching work. Most of the subjects were regular full time university professors. As a group, they exhibit a moderate degree of burnout or emotional exhaustion and personal accomplishment, especially the females. There is no statistical correlation between social demographic variables and BS degree (EE, DP, PA). The most affected group is the so called special professor (n=12) with 23.8±13.4 as a mean EE value that classified them as moderate EE. In personal accomplishment, all of the subjects were under the minimal expected figure to be considered efficient, insofar as it can be ascertained, none of the differences were of statistical significance (p =0.05). The functional variations thus far observed were in blood pressure, stomach upsetting and headache in both sexes with an EE moderate accordingly.El síndrome de Desgaste Profesional o “burnout” (SB) es un conjunto de síntomas y signos producto del estrés crónico en profesionales de servicios con una atención intensa y prolongada a personas que están en una situación de necesidad o de dependencia. El SB consta de tres aspectos: cansancio emocional (CE), despersonalización (DP) y realización personal (RP). El objetivo es medir el grado de desgaste, relacionarlo con variables sociodemográficas y cuantificar la frecuencia de alteraciones fisiológicas posiblemente relacionadas con el SB. Diseño: ex-post facto transversal. Se realizo un muestreo aleatorio mediante encuesta de datos sociodemográficos, alteraciones fisiológicas y del instrumento de evaluación de desgaste profesional. La información se analizó estadísticamente mediante la correlación de Pearson; prueba T., para una muestra de n=51 (31 hombres, 20 mujeres); edad 51±8.22años; profesores asistentes 22.4%, especiales 24.5% y regulares 53.1%; 64% con más de 20 años de experiencia y dedicación a tiempo completo. Tienen un grado moderado de desgaste o CE y de RP principalmente en el sexo femenino conservando un grado de DP mínimo. Los datos sociodemográficos no se correlacionan estadísticamente con el grado de afectación en CE, RP ni en DP. El grupo más afectado en CE fue el de los profesores especiales (n =12) con un promedio de 23.8±13.4 que los clasifica como de afectación intermedia. En RP todos los grupos de docentes estuvieron por debajo del mínimo esperado, aunque estas diferencias no son de significancia estadística (p = 0.05). Los trastornos funcionales más comunes en ambos sexos fueron los hipertensivos, estomacales y las cefaleas coincidiendo respectivamente con un CE intermedio

A Comparing Method of Two Team Behaviours in the Simulation Coach Competition

Proceeding of: Third International Conference on Modeling Decisions for Artificial Intelligence, MDAI 2006, Tarragona, Spain, April 3-5, 2006.The main goal of agent modelling is to extract and represent the knowledge about the behaviour of other agents. Nowadays, modelling an agent in multi-agent systems is increasingly becoming more complex and significant. Also, robotic soccer domain is an interesting environment where agent modelling can be used. In this paper, we present an approach to classify and compare the behaviour of a multi-agent system using a coach in the soccer simulation domain of the RoboCup.Publicad

Influencia del tiempo y temperatura de digestión en mezclas asfálticas mejoradas con grano de caucho reciclado por vía seca

La acumulación de neumáticos fuera de uso se ha convertido en un problema medioambiental complejo al ser un material difícilmente degradable. Por lo que la fundación SWISSCONTACT, mediante el proyecto “Mercados para el Reciclaje”, impulsa la investigación referente a la incorporación de grano de caucho reciclado, que en su primera fase evalúa su adición por vía seca en mezclas asfálticas.Es así que, entre los factores que influyen en las propiedades mecánicas de este tipo de mezclas se encuentran el porcentaje de adición, tiempo y temperatura de digestión necesarios para una adecuada interacción del grano de caucho en la mezcla. De esta forma, la presente investigación evaluó la combinación de estos factores en dos etapas. La primera etapa analizó la influencia de los tiempos de digestión de 1.5 y 2.0 horas a temperaturas de 160 y 170°C seleccionando la mejor combinación de estos factores en el desempeño de resistencia a la humedad. Posteriormente, la segunda etapa empleó la combinación anterior considerando la adición de 0.5, 0.8 y 1.0% de caucho reciclado valorando el efecto de estos en el desempeño a deformación permanente empleando la rueda de Hamburgo.A partir de los resultados obtenidos, se evidencia que el tiempo de digestión de 2.0 horas y temperatura de 170°C para los diferentes porcentajes de adición de grano de caucho reciclado en las mezclas asfálticas evaluadas presentan un incremento del 8 al 15% de resistencia a la humedad y una disminución del 35 al 55% en la deformación permanente en relación a una mezcla sin caucho. Así mismo, se observa que los resultados óptimos corresponden al porcentaje de adición del 0.5% de grano de caucho para un tiempo de digestión de 2.0 horas a 170°C

Mitochondrial Metabolism, Dysfunctions in Senescence Cell and the Possible Interventions through Herbal Medicines

The mitochondria are the cell`s powerhouse. They are considered ubiquitous organelles of all eukaryotic cells, being responsible for the cell’s life and death cycle. Through stimuli in the environment in which they live, mitochondria can modulate their own biogenesis as well as signal retrograde to the nucleus to modify the structure of their proteins. Since the mitochondrial genome contains only 37 genes, much of the encoding of its proteins depends on the nuclear genome. Thus, the communication between mitochondria and the nucleus seems to be a target of science in understanding the pathologies associated with this organelle. Some medicinal herbs have been shown to influence mitochondrial biogenesis, such as Gynostemma pentaphyllun (GP) and berberine, which increase the phosphorylation of proteins AMPactivated protein kinase (AMPK). Just as GP and berberine phosphorylate AMPK in signaling for mitochondrial biogenesis, the sesquiterpene beta-caryophyllene (BCP) demonstrated positive results in reorganizing mitochondrial transcription factors, being an agonist of the peroxisome proliferatoractivated alpha receptor (PPAR-?). Another plant derivative, the non-psychoactive cannabinoid known as cannabidiol (CBD), has been showing control in the metabolism of calcium in the mitochondrial matrix. In this review, we seek to get a closer look at the biochemical mechanisms of action of some of these plants, as well as their synergies in the results of different treatments. In the view of oriental medicines, the use of associated medicinal herbs has always been part of their treatment protocols. However, the effectiveness of these treatments in relation to plant synergy can be observed in future clinical trials for better understanding

Efecto de la variación del tipo de cemento asfáltico en la susceptibilidad a la humedad y deformación permanente en mezclas Stone Mastic Asphalt

Las mezclas asfálticas de granulometría continua son comúnmente empleadas como capas de rodadura en Bolivia. No obstante, el uso de granulometrías discontinuas en mezclas asfálticas, conocidas como Stone Mastic Asphalt (SMA), presentan beneficios en su aplicación ya que su estructura granular proporciona una mayor resistencia a la deformación permanente. Así también, el empleo de cementos asfálticos modificados incrementa la resistencia de los parámetros de desempeño de la mezcla SMA en función al modificante añadido.Es así que, la presente investigación con el fin de evaluar el efecto de la variación del cemento asfáltico en mezclas asfálticas SMA, evaluó el desempeño a la humedad por el método Lottman y deformación permanente mediante la rueda de Hamburgo de mezclas asfálticas tipo SMA elaboradas con cemento asfáltico convencional y modificado, respectivamente. Para esto, se realizó el diseño de las mezclas empleando agregados triturados de la cantera de Parotani, cemento asfáltico con clasificación por penetración 60/70, cemento asfáltico modificado con elastómeros SBS y fibras de celulosa. La dosificación de las mezclas asfálticas SMA fueron desarrolladas conforme la práctica estándar de la AASHTO con designación R46.Tras evaluar los resultados obtenidos se observa que la mezcla SMA con cemento asfáltico SBS presenta aumentos del 15,67% a la resistencia a la humedad y 38.89% a la resistencia a la deformación permanente en comparación a la mezcla SMA con asfalto 60/70. Sin embargo, se evidencia que la mezcla SMA con cemento asfáltico SBS presenta menor resistencia a la tensión indirecta que la mezcla SMA con asfalto 60/70

Application of ISUP Grading in a Series of Papillary Renal Cell Carcinoma Cases from a Tertiary Institution

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Human monocyte-derived macrophage responses to M. tuberculosis differ by the host’s tuberculosis, diabetes or obesity status, and are enhanced by rapamycin

Human macrophages play a major role in controlling tuberculosis (TB), but their anti-mycobacterial mechanisms remain unclear among individuals with metabolic alterations like obesity (TB protective) or diabetes (TB risk). To help discern this, we aimed to: i) Evaluate the impact of the host’s TB status or their comorbidities on the anti-mycobacterial responses of their monocyte-derived macrophages (MDMs), and ii) determine if the autophagy inducer rapamycin, can enhance these responses. We used MDMs from newly diagnosed TB patients, their close contacts and unexposed controls. The MDMs from TB patients had a reduced capacity to activate T cells (surrogate for antigen presentation) or kill M. tuberculosis (Mtb) when compared to non-TB controls. The MDMs from obese participants had a higher antigen presenting capacity, whereas those from chronic diabetes patients displayed lower Mtb killing. The activation of MDMs with rapamycin led to an enhanced anti-mycobacterial activity irrespective of TB status but was not as effective in patients with diabetes. Further studies are warranted using MDMs from TB patients with or without metabolic comorbidities to: i) elucidate the mechanisms through which host factors affect Mtb responses, and ii) evaluate host directed therapy using autophagy-inducing drugs like rapamycin to enhance macrophage function

COLOMBOS v3.0: leveraging gene expression compendia for cross-species analyses

COLOMBOS is a database that integrates publicly available transcriptomics data for several prokaryotic model organisms. Compared to the previous version it has more than doubled in size, both in terms of species and data available. The manually curated condition annotation has been overhauled as well, giving more complete information about samples’ experimental conditions and their differences. Functionality-wise cross-species analyses now enable users to analyse expression data for all species simultaneously, and identify candidate genes with evolutionary conserved expression behaviour. All the expression-based query tools have undergone a substantial improvement, overcoming the limit of enforced co-expression data retrieval and instead enabling the return of more complex patterns of expression behaviour. COLOMBOS is freely available through a web application at http://colombos.net/. The complete database is also accessible via REST API or downloadable as tab-delimited text file

Human M1 macrophages express unique innate immune response genes after mycobacterial infection to defend against tuberculosis

Mycobacterium tuberculosis (Mtb) is responsible for approximately 1.5 million deaths each year. Though 10% of patients develop tuberculosis (TB) after infection, 90% of these infections are latent. Further, mice are nearly uniformly susceptible to Mtb but their M1-polarized macrophages (M1-MΦs) can inhibit Mtb in vitro, suggesting that M1-MΦs may be able to regulate anti-TB immunity. We sought to determine whether human MΦ heterogeneity contributes to TB immunity. Here we show that IFN-γ-programmed M1-MΦs degrade Mtb through increased expression of innate immunity regulatory genes (Inregs). In contrast, IL-4-programmed M2-polarized MΦs (M2-MΦs) are permissive for Mtb proliferation and exhibit reduced Inregs expression. M1-MΦs and M2-MΦs express pro- and anti-inflammatory cytokine-chemokines, respectively, and M1-MΦs show nitric oxide and autophagy-dependent degradation of Mtb, leading to increased antigen presentation to T cells through an ATG-RAB7-cathepsin pathway. Despite Mtb infection, M1-MΦs show increased histone acetylation at the ATG5 promoter and pro-autophagy phenotypes, while increased histone deacetylases lead to decreased autophagy in M2-MΦs. Finally, Mtb-infected neonatal macaques express human Inregs in their lymph nodes and macrophages, suggesting that M1 and M2 phenotypes can mediate immunity to TB in both humans and macaques. We conclude that human MФ subsets show unique patterns of gene expression that enable differential control of TB after infection. These genes could serve as targets for diagnosis and immunotherapy of TB