Medicion empirica del grado de competitividad a traves de la matriz Can-Cepal del comercio exterior de uva de mesa y pasas.

140 p.En esta tesis, se presenta la aplicación de la Matriz CAN de CEPAL, como forma de medición empírica de la competitividad de los productos agrícolas Uva de Mesa y Pasas, sobre la base de resultados observados de su comercio internacional, por un periodo de 16 anos entre Chile y los países del MERCOSUR, del NAFTA, Holanda y Japón. Palabras claves: Dinamismo, Posicionamiento, Atractividad, Exportaciones e Importaciones

Reaction mechanism of hydrogen activation by frustrated Lewis pairs

Typically, a Lewis acid and a base react with each other and form classic acid base adducts. The neutralization reaction is however prevented by the introduction of bulky substitutes and this interesting finding leads to a new concept called frustrated Lewis pairs, FLPs. Since both reactivities of Lewis acids and bases are remained in the same systems, FLPs have been shown many important applications. One of them is hydrogen activation, which showed for the first time the use of a non metal catalyst for that purpose. In this mini review, we have summarized all important findings regarding the H2 activation by FLPs. This includes preorganisation of FLPs, reaction path for the activation, polarization of HH bond and the factors affected the reactivity. In light of some recent developments, we aim to clarify the reaction mechanism for the H2 actitation by FLPs, which has been under debate for decades since the first discovery of FLPs. We believe that this mini review can be served as a guideline for the future fundamental studies and industrial applications

Infectious phage particles packaging antibiotic resistance genes found in meat products and chicken feces

Bacteriophages can package part of their host's genetic material, including antibiotic resistance genes (ARGs), contributing to a rapid dissemination of resistances among bacteria. Phage particles containing ARGs were evaluated in meat, pork, beef and chicken minced meat, and ham and mortadella, purchased in local retailer. Ten ARGs (blaTEM, blaCTX-M-1, blaCTX-M-9, blaOXA-48, blaVIM, qnrA, qnrS, mecA, armA and sul1) were analyzed by qPCR in the phage DNA fraction. The genes were quantified, before and after propagation experiments in Escherichia coli, to evaluate the ability of ARG-carrying phage particles to infect and propagate in a bacterial host. According to microbiological parameters, all samples were acceptable for consumption. ARGs were detected in most of the samples after particle propagation indicating that at least part of the isolated phage particles were infectious, being sul1the most abundant ARG in all the matrices followed by β-lactamase genes. ARGs were also found in the phage DNA fraction of thirty-seven archive chicken cecal samples, confirming chicken fecal microbiota as an important ARG reservoir and the plausible origin of the particles found in meat. Phages are vehicles for gene transmission in meat that should not be underestimated as a risk factor in the global crisis of antibiotic resistance.info:eu-repo/semantics/publishedVersio

Infectious phage particles packaging antibiotic resistance genes found in meat products and chicken feces

This work was supported by the Spanish Ministerio de Innovación y Ciencia (AGL2016-75536-P), the Agencia Estatal de Investigación (AEI) and the European regional fund (ERF), the Generalitat de Catalunya (2017SGR170) and the Centre de Referència en Biotecnologia (XeRBa). CERCA Programme from the Generalitat de Catalunya is also acknowledged. M.B.-J. has a grant from COLCIENCIAS (Republic of Colombia). P.B.-P. has a grant from the Spanish Ministry of Economy, Industry and Competitiveness (BES-2017-081296). L.R.-R. is supported by the Beatriu de Pinos postdoctoral programme of the Government of Catalonia's Secretariat for Universities and Research of the Ministry of Economy and Knowledge.Bacteriophages can package part of their host's genetic material, including antibiotic resistance genes (ARGs), contributing to a rapid dissemination of resistances among bacteria. Phage particles containing ARGs were evaluated in meat, pork, beef and chicken minced meat, and ham and mortadella, purchased in local retailer. Ten ARGs (bla, bla, bla, bla, bla, qnrA, qnrS, mecA, armA and sul1) were analyzed by qPCR in the phage DNA fraction. The genes were quantified, before and after propagation experiments in Escherichia coli, to evaluate the ability of ARG-carrying phage particles to infect and propagate in a bacterial host. According to microbiological parameters, all samples were acceptable for consumption. ARGs were detected in most of the samples after particle propagation indicating that at least part of the isolated phage particles were infectious, being sul1the most abundant ARG in all the matrices followed by β-lactamase genes. ARGs were also found in the phage DNA fraction of thirty-seven archive chicken cecal samples, confirming chicken fecal microbiota as an important ARG reservoir and the plausible origin of the particles found in meat. Phages are vehicles for gene transmission in meat that should not be underestimated as a risk factor in the global crisis of antibiotic resistance

Especificacion y Poder del Metodo de Estudio de eventos en el largo plazo: Una aplicacion con retornos mensuales argentinos.

67 p.El objetivo de un estudio de eventos es cuantificar el efecto de un evento en el valor de mercado de las acciones que componen el patrimonio de una empresa. Con el fin de validar dicha metodología en mercados de capitales poco profundos, el presente estudio utiliza el enfoque de simulación de Brown y Warner con datos mensuales del mercado accionario Argentino. Se examina el poder y la especificación de los tests paramétricos utilizados frecuentemente en la metodología de estudio de eventos: El Test t Estandarizado, el Test t de Corte Transversal y el de Portafolio. Se analizaron 250 muestras de 50 acciones cada una, seleccionadas de forma aleatoria y con repetición, obtenidas de la Bolsa de Valores Argentina. A través del Software Eventuspro* se simula el efecto de un “evento económico” sobre el rendimiento de los activos que componen dichas muestras. Con esto se busca analizar la especificación de los tres tests paramétricos y el poder para detectar los diferentes niveles de retorno anormal introducidos en las muestras. Pese a la evidencia sobre de la existencia de sesgos que provocarían siempre una mala especificación de los tests paramétricos que utilizan datos mensuales, en el caso del mercado de capitales argentino esto no se cumple ya que, la combinación óptima que mejora la especificación en todos los periodos estudiado es el test-t de portafolio a un nivel de significancia del 5% basado en los retornos generados por el Modelo de Ajuste al Mercado. En términos de poder predictivo del test paramétrico, el test-t estandarizado, a un nivel de significancia del 5%, es el más poderoso. Sin embargo, si tomamos en cuenta sólo aquellos tests que se encuentran bien especificados para una ventana de un mes encontramos que el test con más poder es el de corte transversal, a un nivel de significancia del 5%

Unconventional OFF–ON Response of a Mono(calix[4]arene)-Substituted BODIPY Sensor for Hg2+ through Dimerization Reversion

A new selective fluorogenic chemosensor for Hg2+, which combines a calixarene derivative with a BODIPY core as a fluorescent reporter, is described. The remarkable change in its fluorogenic properties in DMSO and CHCl3 has been analyzed. A study of its spectral properties on dilution, along with molecular modeling studies, allowed us to explain that this behavior involves the formation of a J-dimer, as well as how the sensing mechanism of Hg2+ proceeds

Real-Space Approach to the Reaction Force: Understanding the Origin of Synchronicity/Nonsynchronicity in Multibond Chemical Reactions

In this article, we present a complementary analysis based on the reaction force F(ζ)/reaction force constant κ(ζ) and noncovalent interactions (NCI) index to characterize the energetics (kinetic and thermodynamics) and mechanistic pathways of two sets of multibond chemical reactions, namely, two double-proton transfer and two Diels-Alder cycloaddition reactions. This approach offers a very straightforward and useful way to delve into a deeper understanding of this type of process. While F(ζ) allows the partition of the whole pathway into three regions or phases, κ(ζ) describes how orchestrated are the bond-breaking and bond-formation events. In turn, NCI indicates how the inter- and intramolecular bonds evolve. The most innovative aspect is the inclusion of the formation of the reactant complex along the pathway, which, by means of NCI, unveils the early molecular recognition and the comprehension of its role in determining the degree of the synchronicity/nonsynchronicity of one-step processes. This approach should be a useful and alternative tool to characterize the energetics and the mechanism of general chemical reactions. © 2020 American Chemical Society.Indexación: Scopu

Chemical and biological analysis of 4-acyloxy-3-nitrocoumarins as trypanocidal agents

Chagas disease is the most widespread contagious tropical disease in Latin America, being an important public health problem. Treatments against this disease are still very ineffective, presenting several side effects. Therefore, the search for alternative therapeutic solutions is urgent. In the present work, we evaluate the trypanocidal activity and the mechanism of action of a select series of synthetic 4-acyloxy-3-nitrocoumarins. All the coumarin derivatives showed moderate trypanocidal activity in trypomastigotes, along with low cytotoxicity. In addition, compound 1 decreased the number of infected Vero cells in an intracellular T. cruzi model. Electron spin resonance and electrochemical studies showed the formation of nitro radical anions. The Fukui index provided additional information to elucidate the proposed reduction mechanism. Furthermore, in vitro radical formation studies demonstrated the potential of these compounds to achieve higher concentrations of intracellular free radicals, proposing oxidative stress as a possible trypanocidal mechanism. Furthermore, no correlation was observed between the diffusion of these compounds, which shows that lipophilicity is not a predominant factor for activity. Elsevier Ltd. All rights reservedThis project was partially supported by the University of Porto and University of Santiago de Compostela. MJM would like to thank Xunta de Galicia (Galician Plan of Research, Innovation and Growth 2011–2015, Plan I2C, ED481B 2014/086–0 and ED481B 2018/007) and Fundação para a Ciência e Tecnologia (CEECIND/02423/2018 and UIDB/00081/2020). FS would like to thank FONDECYT 1190340 and REDES170126, COA would like to thank FONDECYT 1190340, JDM would like to thank FONDECYT 1170126 and ANID/PCI REDES 170126, and MMB would like to thank FONDECYT Postdoctoral 3190449S

Electrospraying as a Technique for the Controlled Synthesis of Biocompatible PLGA@Ag2S and PLGA@Ag2S@SPION Nanocarriers with Drug Release Capability

Ag2S nanoparticles are near-infrared (NIR) probes providing emission in a specific spectral range (~1200 nm), and superparamagnetic iron oxide nanoparticles (SPION) are colloidal systems able to respond to an external magnetic field. A disadvantage of Ag2S NPs is the attenuated luminescent properties are reduced in aqueous media and human fluids. Concerning SPION, the main drawback is the generation of undesirable clusters that reduce particle stability. Here, we fabricate biocompatible hybrid nanosystems combining Ag2S NPs and SPION by the electrospraying technique for drug delivery purposes. These nanostructures are composed of poly(lactic-co-glycolic acid) (PLGA) as the polymeric matrix in connection with both Ag2S NPs and SPIONs. Initially, we fabricate a hybrid colloidal nanosystem composed of Ag2S NPs in connection with PLGA (PLGA@Ag2S) by three different routes, showing good photoluminescent (PL) properties with relatively high average decay times. Then, we incorporate SPIONs, obtaining a PLGA polymeric matrix containing both Ag2S NPs and SPION (PLGA@Ag2S@SPION). Interestingly, in this hybrid system, the location of Ag2S NPs and SPIONs depends on the synthesis route performed during electrospraying. After a detailed characterization, we demonstrate the encapsulation and release capabilities, obtaining the kinetic release using a model chemotherapeutic drug (maslinic acid). Finally, we perform in vitro cytotoxicity assays using drug-loaded hybrid systems against several tumor cell lines.This research was funded “Atracción de Talento” fellowship from the Comunidad de Madrid, grant number 2018-T1/IND-10736; the Universidad Complutense de Madrid, grant number UCM-Santander (CT63/19-CT64/19); the Junta de Andalucía (P18-HO-3882, P20_00540, A-CTS-666-UGR20-FEDER); and Instituto de Salud Carlos III (PI19/01478-FEDER). P.G. acknowledges financial support from the Spanish government (MICIU) through the Ramon y Cajal research program (RyC2019-028414-I). M.F. thanks the Comunidad Autonoma de Madrid for research project No. 2017-T1/BIO-4992 (“Atracción de Talento” Action) cofunded by Universidad Complutense de Madrid. M.F. is grateful to Instituto de Salud Carlos III (ISCIII) for project No DTS20/00109 (AES-ISCIII). M.F. and L.L.C would also like to thank Comunidad de Madrid for the predoctoral grant IND2020/BIO-17523.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Propuesta para el mejoramiento de los procesos de subgerencia de monitoreo y disponibilidad de servicios de clientes de Entel

Tesis (Ingeniero Industrial)Actualmente Entel se está desarrollando en un ambiente tremendamente competitivo y dinámico. La conectividad fija y móvil, con voz e internet, los teléfonos inteligentes, los servicios TI que se prestan sobre y a través de las Redes, entre otras innovaciones, están cambiando la vida de las personas y la forma en que están operando las empresas. Debido al constante crecimiento tecnológico mundial y a la importancia que tienen actualmente las Redes de Datos en las empresas, es cada vez más necesario mantener operativas las redes en todo momento y/o solucionar en el más breve espacio de tiempo los problemas que ocurran en sus enlaces. Es por esto que el Centro de Monitoreo de Servicios de Cliente ha adquirido un rol clave dentro del flujo de atención en la compañía y para los Clientes es cada vez más importante contar con este servicio. Es así como durante los últimos años los clientes han aumentado en gran cantidad (150 clientes en 2010 a 208 Clientes 2013) por lo que se ha tenido que aumentar la dotación de personal del CMSC. Sin embargo, los problemas de atención han ido en aumento, afectando directamente a la compañía, generando multas asociadas a atención de incidencias, entrega de informes mensuales y fallas por corte de servicio que en realidad son trabajos programados no informados. También afecta la imagen de la compañía como socio Tecnológico de las empresas 13 más grandes del país y haciendo que pierda diferenciación con la competencia. En la actualidad las personas y las empresas no necesitan solo de la tecnología. Lo que necesitan es una buena experiencia de uso de esta tecnología, que les permita mejorar su calidad de vida y en el caso de las empresas, su productividad. Y es aquí donde Entel sitúa su estrategia y propuesta como empresa. Es en este contexto, Entel se ha posicionado como un actor capaz de captar este gran desarrollo tecnológico, entenderlo y encauzarlo a un servicio distintivo y con valor para los Clientes. La vocación de Entel es ofrecer la mejor experiencia de servicio a los Clientes, teniendo como base redes y datacenters modernos, además de una marca fuertemente posicionada en el mercado. Al final del 2012 los clientes superaban los 10 millones en servicios móviles, haciendo que Entel liderara, de esta forma, la industria con una participación de 39% de los clientes activos, con alta participación en el mercado Personas y con niveles sobre el 50% en las empresas y grandes corporaciones. Dentro de su visión Entel aspira a dar a los clientes una “experiencia distintiva de servicio”. Es por todo esto, que se hace fundamental aplicar mejoras en la Subgerencia de Monitoreo y Disponibilidad de Servicio, de modo que disminuyan los reclamos, mejore la eficiencia y la calidad del servicio, aumentando la satisfacción de los Clientes