Plasticization effect of epoxidized cottonseed oil (ECSO) on poly(lactic acid)

[EN] In this work, the use of an environmentally friendly plasticizer derived epoxidized cottonseed oil (ECSO) for poly(lactic acid) (PLA) is proposed. Melt extrusion was used to plasticize PLA formulations with different ECSO contents in the 0 - 10 wt.%. PLA formulation with 10 wt.% shows a remarkable increase in mechanical ductile properties with a percentage increase in elongation at break of more than 1100% and a noticeable increase in the impact absorbed energy. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) revealed a clear decrease in the glass transition temperature of neat PLA as the ECSO content increased. Field emission scanning electron microscopy (FESEM) of fractured surfaces from impact tests showed an improvement of ductility with typical rough and porous topographies. Migration tests in n-hexane at different temperatures revealed very low migration properties thus leading to new interesting plasticizers for improved PLA industrial formulations.This research was supported by the Spanish Ministry of Economy and Competitiveness - MINECO, Ref: MAT2014-59242-C2-1-R. Authors also thank to "Conselleria d'Educacio, Cultura i Esport" - Generalitat Valenciana, Ref: GV/2014/008 for financial support. A. Carbonell-Verdu wants to thank Universitat Politecnica de Valencia for financial support through an FPI grant. D. Garcia-Garcia wants to thanks the Spanish Ministry of Education, Culture and Sports for their financial support through an FPU grant (FPU13/06011).Carbonell-Verdu, A.; Samper, M.; Garcia-Garcia, D.; Sanchez-Nacher, L.; Balart, R. (2017). Plasticization effect of epoxidized cottonseed oil (ECSO) on poly(lactic acid). Industrial Crops and Products. 104:278-286. https://doi.org/10.1016/j.indcrop.2017.04.050S27828610

PLA films with improved flexibility properties by using maleinized cottonseed oil

[EN] This work assesses the potential of maleinized cottonseed oil MCSO as plasticizer in poly(lactic acid) PLA films with improved ductile behaviour. The effects of MCSO are compared with commercially available maleinized oil, i.e. maleinized linseed oil MLO in terms of mechanical, thermal and barrier properties, as well as morphology changes. Plasticized PLA formulations were obtained with a maleinized oil content in the 0 10 wt% range. Addition of both maleinized vegetable oils leads to a slight decrease in the glass transition temperature (Tg) of neat PLA from 63 °C to 60 61 °C. Nevertheless, MCSO provides better overall properties. Addition of 7.5 wt% MCSO increases the elongation at break by 292%. Regarding the barrier properties, both maleinized vegetable oils increase the oxygen transmission rate OTR. Nevertheless, this increase is less pronounced in the case of MCSO thus indicating its higher efficiency compared to MLO. On the other hand, addition of both maleinized vegetable oils do not compromise the overall disintegration of the obtained PLA formulations, thus positioning these additives as environmentally friendly solutions to increase ductile properties in PLA-based films.This research was supported by the Ministry of Economy and Competitiveness - MINECO, Ref: MAT2014-59242-C2-1-R. Carbonell-Verdu wants to thank Universitat Politecnica de Valencia for financial support through an FPI grant. Garcia-Garcia wants to thanks the Spanish Ministry of Education, Culture and Sports for their financial support through an FPU grant (FPU13/06011).Carbonell-Verdu, A.; Garcia-Garcia, D.; Dominici, F.; Torre, L.; Sanchez-Nacher, L.; Balart, R. (2017). PLA films with improved flexibility properties by using maleinized cottonseed oil. European Polymer Journal. 91:248-259. https://doi.org/10.1016/j.eurpolymj.2017.04.013S2482599

A 2D ray-tracing based model for wave propagation through forests at micro-and millimeter wave frequencies

This paper proposes the extension of a 2-D ray-tracing-based model for radiowave propagation in the presence of trees and vegetation areas to include real-sized trees and outdoor forest scenarios. The original propagation model proved to be suitable to characterize the electromagnetic behavior in the presence of indoor tree formation scenarios, despite some limitations found when applied to real-sized trees. In addition, the original propagation model requires the prior knowledge of the trees’ re-radiation function to extract the relevant propagation input parameters, which is not always possible to obtain in outdoor scenarios. Therefore, an empirical method to extract the relevant input propagation parameters based on simple measurements is proposed. The performance of the proposed propagation model extension is extensively assessed in both the line-of-trees and tree formation scenarios, including various (and mixed) species, both in- and out-of-leaf foliation states, and at three signal frequencies. Finally, depending on the type of scenario, a benchmark between the proposed propagation model and both the radiative energy transfer (RET) and discrete RET (dRET) models, for line-of-trees and tree formation, respectively, is presented.info:eu-repo/semantics/publishedVersio

Understanding the applicability of terahertz flow-guided nano-networksfor medical applications

Terahertz-based nano-networks are emerging as a groundbreaking technology able to play a decisive role in future medical applications owing to their ability to precisely quantify figures, such as the viral load in a patient or to predict sepsis shock or heart attacks before they occur. Due to the extremely limited size of the devices composing these nano-networks, the use of the Terahertz (THz) band has emerged as the enabling technology for their communication. However, the characteristics of the THz band, which strictly reduce the communication range inside the human body, together with the energy limitations of nano-nodes make the in-body deployment of nano-nodes a challenging task. To overcome these problems, we propose a novel in-body flow-guided nano-network architecture consisting of three different devices: i) nano-node, ii) nano-router, and iii) bio-sensor. As the performance of this type of nano-network has not been previously explored, a theoretical framework capturing all its particularities is derived to properly model its behavior and evaluate its feasibility in real medical applications. Employing this analytical model, a thorough sensitivity study of its key parameters is accomplished. Finally, we analyze the terahertz flow-guided nano-network design to satisfy the requirements of several medical applications of interest

High toughness poly (lactic acid) (PLA) formulations obtained by ternary blends with poly (3-hydroxybutyrate) (PHB) and flexible polyesters from succinic acid

[EN] This work reports the development of poly(lactic acid) (PLA) formulations with improved toughness by ternary blends with poly(3-hydroxybutyrate) (PHB) and two different flexible polyesters derived from succinic acid, namely poly(butylene succinate) (PBS) and a copolymer, poly(butylene succinate-co-adipate) (PBSA). The main aim of this work is to increase the low intrinsic toughness of PLA without compromising the thermal properties by manufacturing ternary blends using epoxidized vegetable oils as compatibilizer agents. The ternary blends were manufactured by reactive extrusion in a co-rotating extruder and were subjected to mechanical, thermal, thermos-mechanical and morphology characterization. The obtained results confirm that these two succinic acid-derived polymers, i.e., PBS and PBSA, positively contribute to increase ductile properties in ternary blends with PLA and PHB with a subsequent improvement on impact toughness. In addition, both epoxidized vegetable oils, ELO and ESBO, are responsible for somewhat compatibilization between all three polyesters in blends which gives improved ductile properties with regard to uncompatibilized ternary blends. In addition, the temperature range in which these materials can be used is broader than ternary blends with other flexible polyester such as poly(e-caprolactone), as both PBS and PBSA melt at about 100 °C. These PLA-based materials with improved impact properties offer interesting applications in the packaging industry.This work was supported by the Ministry of Economy and Competitiveness (MINECO) Grant Numbers MAT2014-59242-C2-1-R and MAT2017-84909-C2-2-R. L. Quiles-Carrillo acknowledges Generalitat Valenciana (GV) for financial support through a FPI Grant (ACIF/2016/182) and the Spanish Ministry of Education, Culture, and Sports (MECD) for his FPU Grant (FPU15/03812).Garcia-Campo, M.; Quiles-Carrillo, L.; Sanchez-Nacher, L.; Balart, R.; Montanes, N. 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La sostenibilidad de la política fiscal en el América Latina: El caso de Venezuela

La economía venezolana se ha visto sometida desde mediados de la década de los setenta a un proceso de marcada inestabilidad y volatilidad, causado fundamentalmente por los shocks provenientes del mercado petrolero. La política fiscal ha jugado un rol determinante en la transmisión de esos shocks al resto de la economía. Por una parte, el gasto público ha mostrado un comportamiento procíclico en relación a los ingresos petroleros, transmitiendo la volatilidad de estos últimos a través de la demanda agregada interna y por tanto en las presiones inflacionarias y en el crecimiento económico. Por otra parte, el uso del tipo de cambio como mecanismo de corrección fiscal en algunas oportunidades y en otras como ancla nominal, conjuntamente con el comportamiento procíclico del gasto, han creado una situación prolongada de "stop and go" o de expansiones y ajustes recurrentes y transitorios con elevados costos de crecimiento, inflación y empobrecimiento de la población.

Auditoría financiera y su relación en la informalidad de las cooperativas financieras, en la provincia de Chincha-Ica, periodo 2021

El trabajo de investigación tiene por objetivo definir la relación que hay entre la auditoria financiera y la informalidad de las cooperativas de la Provincia de Chincha. La auditoría financiera es importante, ya que su aplicación nos brindara información que ayudara a la toma de las decisiones de las cooperativas financieras. El trabajo de investigación es tipo básica porque busca desarrollar y ahondar los conocimientos contables y dar alternativas de solución al problema de investigación, que es de enfoque cuantitativo, nivel correlacional, no experimental de corte transversal, porque no se manipularon las variables y fueron dentro de un determinado tiempo. La muestra estuvo conformada por 30 trabajadores, que laboran en las cooperativas. La técnica e instrumentalización de recojo de datos es la encuesta y como instrumento el cuestionario el cual se midió en la escala de Likert en ambas variables. Se utilizo el criterio de juicio de expertos para validez de los instrumentos y se usó el Alfa de Cronbach para a la confiabilidad de variables y para verificar la relación entre la auditoria financiera y la informalidad se utilizó la prueba estadística de Rho Spearman (0.905) donde muestran que existe correlación positiva moderada entre ambas variables de estudio

International scientific collaboration in HIV and HPV: a network analysis.

Research endeavours require the collaborative effort of an increasing number of individuals. International scientific collaborations are particularly important for HIV and HPV co-infection studies, since the burden of disease is rising in developing countries, but most experts and research funds are found in developed countries, where the prevalence of HIV is low. The objective of our study was to investigate patterns of international scientific collaboration in HIV and HPV research using social network analysis. Through a systematic review of the literature, we obtained epidemiological data, as well as data on countries and authors involved in co-infection studies. The collaboration network was analysed in respect to the following: centrality, density, modularity, connected components, distance, clustering and spectral clustering. We observed that for many low- and middle-income countries there were no epidemiological estimates of HPV infection of the cervix among HIV-infected individuals. Most studies found only involved researchers from the same country (64%). Studies derived from international collaborations including high-income countries and either low- or middle-income countries had on average three times larger sample sizes than those including only high-income countries or low-income countries. The high global clustering coefficient (0.9) coupled with a short average distance between researchers (4.34) suggests a "small-world phenomenon." Researchers from high-income countries seem to have higher degree centrality and tend to cluster together in densely connected communities. We found a large well-connected community, which encompasses 70% of researchers, and 49 other small isolated communities. Our findings suggest that in the field of HIV and HPV, there seems to be both room and incentives for researchers to engage in collaborations between countries of different income-level. Through international collaboration resources available to researchers in high-income countries can be efficiently used to enroll more participants in low- and middle-income countries

End of life care in nursing homes in Spain: exploratory analysis and evidences of validity of a new scale.

This document is the accepted manuscript version of the following article: Maria Remedios Sánchez-GarcÍa, Jose Antonio Gutiérrez-Romero, Manuel Fernández Alcántara, César Hueso-Montoro, Claire Goodman, and Rafael Montoya-Juárez, ‘End of life care in nursing homes in Spain: Exploratory analysis and evidences of validity of a new scale’, Applied Nursing Research, Vol. 37: 6-12, October 2017. Under embargo until 5 July 2018. The final, definite version is available online at DOI: https://doi.org/10.1016/j.apnr.2017.07.001.Quality end-of-life care is a central issue in nursing homes, requiring the assessment of individual and family needs by health professionals. Although previous instruments have been developed, they usually rely on family reports and have been adapted from other clinical contexts (hospital or primary care). It is important to consider how health care professionals working in nursing homes perceive what is necessary to achieve quality end-of-life care. In this study, the objective was to develop an instrument to assess quality of end-of-life care in the context of Spanish care homes. A 24 item scale Nursing Home End of Life Care Scale (NHEOLC) was developed through a systematic evaluation of existing tools combined with an iterative process of consultation with group experts in end of life care in long term care settings. A total of 307 health care professionals agreed to participate in the study and completed the scale. The scale was grouped in six dimensions: physical, psychological aspects and spiritual aspects of care, family care, bereavement, and patient/family preferences management. The results suggest an adequate factorial structure of the scale and good internal consistency for the total score and the subscales. In addition, the results showed significant differences depending on the size of the nursing home, the category of health professionals, and their own perceptions of his work regarding end-of-life care.Peer reviewe

Microarrays as Platform for Multiplex Assays in Biomarker and Drug Discovery

Despite the tremendous advances in the understanding of the molecular mechanisms and the complexity of the diseases is one of the present challenges for the scientific community; then, novel strategies are required to be designed and developed for effective strategies for early diagnosis and treatment. As many cellular alterations are observed at protein level, high-throughput assays are dramatically needed for biomarker discovery. Herein, we describe advantages and limitations of protein microarrays, as proteomics strategy useful for multiplex and high-throughput protein characterization in clinical samples. Finally, a few examples are discussed; mostly of them related to currently disease biomarkers already identified in proximal fluids by protein arrays are discussed