The effect of processing routes on the thermal and mechanical properties of poly(urethane-isocyanurate) nanocomposites

A systematic investigation of four processing routes was implemented so as to evaluate the thermal and mechanical properties of nanosilica (NS) reinforced poly(urethane-isocyanurate) nanocomposites (NC). The NS dispersion in the Polmix and the Isomix routes was performed in the polyol and the isocyanate precursor, respectively. The Isopol and the Solvmix routes consisted on the dispersion of the filler after the mixing of the precursors and with the aid of solvents, respectively. The NS dispersion, fractography (SEM, TEM), flexural and tensile mechanical properties, thermogravimetric analysis and FTIR analysis of NCs was performed as a function of processing route, isocyanate index, and NS concentration. Each route produced a NC with distinct properties, which were correlated to the NS agglomeration degree and how the NS affected the thermal transitions of the HS and the relative ratio of urethane and isocyanurate chemical groups. For example, the NC prepared with the Polmix route had substantial improvements of σt and εt of around +40 and +52%, respectively and an improved thermal resistance of the Hard Segments.Fil: Kenny, José María. Università di Perugia; ItaliaFil: Torre, Luigi. Università di Perugia; ItaliaFil: Chiacchiarelli, Leonel Matias. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Nanostructured morphology of a random P(DLLA-co-CL) copolymer

The random architecture of a commercial copolymer of poly(DL-lactic acid) and poly(ε-caprolactone), poly(DL-lactide-co-caprolactone), has been characterized by chemical structure analysis from hydrogen-1 nuclear magnetic resonance results. Moreover, spherical nanodomains have been detected in the thin films of this copolymer obtained after solvent evaporation. These nanodomains studied by atomic force microscopy and transmission elecron microscopy grow progressively under annealing until they collapse and form a homogenous disordered structure. This is the first time that the nanostructure of random poly(DL-lactic acid)/poly-(ε-caprolactone) copolymers is revealed, representing one of few experimental evidences on the possible nanostructuration of random copolymers

Coercivity and Magnetic Anisotropy of (Fe0.76Si0.09B0.10P0.05)97.5Nb2.0Cu0.5 Amorphous and Nanocrystalline Alloy Produced by Gas Atomization Process

We present the evolution of magnetic anisotropy obtained from the magnetization curve of (Fe0.76Si0.09B0.10P0.05)97.5Nb2.0Cu0.5 amorphous and nanocrystalline alloy produced by a gas atomization process. The material obtained by this process is a powder exhibiting amorphous character in the as-atomized state. Heat treatment at 480 °C provokes structural relaxation, while annealing the powder at 530 °C for 30 and 60 min develops a fine nanocrystalline structure. Magnetic anisotropy distribution is explained by considering dipolar effects and the modified random anisotropy model.Author Kenny L. Alvarez thanks Becas Chile (CONICYT) for financial support. The authors thank SGIker of UPV/EHU for technical and human support. This work was supported by the European Commission (ERDF and ESF programs). Authors M. Ipatov, L. Domínguez and J. Gonzalez acknowledge the University of the Basque Country for the support under the scheme “Ayudas a Grupos Consolidados” (Ref. PPG17/35)

Análisis ético y político criminal de la Ley 1774 de 2016

Taking into account the Law 1774 of 2016 on the protection of animals, it ispertinent to analyze the ethical foundations that support this regulation, what are theimplications in the field of criminal law and dogmatics when assuming animals as a legalright and the consequences in political-criminal matters when creating a new crime forthose who seriously mistreat these beings.Teniendo en cuenta la expedición de la Ley 1774 de 2016 acerca de la protección de los animales, resulta pertinente analizar cuáles son los fundamentos éticos que soportan esta regulación, cuáles son las implicaciones en el ámbito de la dogmática jurídico penal al asumir a los animales como un bien jurídico y cuáles son las consecuencias en materia polítco-criminal al crearse un nuevo delito para quienes los maltraten gravemente

Nano-biocomposite films with modified cellulose nanocrystals and synthesized silver nanoparticles

Ternary nano-biocomposite films based on poly(lactic acid) (PLA) with modified cellulose nanocrystals (s-CNC) and synthesized silver nanoparticles (Ag) have been prepared and characterized. The functionalization of the CNC surface with an acid phosphate ester of ethoxylated nonylphenol favoured its dispersion in the PLA matrix. The positive effects of the addition of cellulose and silver on the PLA barrier properties were confirmed by reductions in the water permeability (WVP) and oxygen transmission rate (OTR) of the films tested. The migration level of all nano-biocomposites in contact with food simulants were below the permitted limits in both non-polar and polar simulants. PLA nano-biocomposites showed a significant antibacterial activity influenced by the Ag content, while composting tests showed that the materials were visibly disintegrated after 15 days with the ternary systems showing the highest rate of disintegration under composting conditions.L.V. would like to acknowledge the financial support from MIUR, PRIN 2010–11 project entitled “Nanomed” (prot.2010FPTBSH 009). M.P. and A.J. acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness (MAT2011-28648-C02-1)

Controlled Release of Thymol from Poly(Lactic Acid)-Based Silver Nanocomposite Films with Antibacterial and Antioxidant Activity

Thymol and silver nanoparticles (Ag-NPs) were used to develop poly(lactic acid) (PLA)-based films with antioxidant and antibacterial performance. Different amounts of thymol (6 and 8 wt%) and 1 wt% Ag-NPs were added to PLA to produce the active films. Ag-NPs and thymol were successfully identified in the nanocomposite structures using spectroscopic techniques. A kinetic study was performed to evaluate the release of thymol and Ag-NPs from the nanocomposites to an aqueous food simulant (ethanol 10%, v/v) at 40 °C. The diffusion of thymol from the polymer matrix was affected by the presence of non-migrating Ag-NPs, which showed non-Fickian release behavior. The ternary system including 1 wt% Ag-NPs and 8 wt% thymol showed clear antibacterial performance by reducing the cell viability of Escherichia coli and Staphylococcus aureus by around 40% after 3 and 24 h of storage at 4, 25, and 37 °C compared to neat PLA. Significant antioxidant behavior of all active films was also confirmed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The obtained nanocomposite films based on PLA and the addition of Ag-NPs and thymol were proven to have combined antioxidant and antibacterial performance, with controlled release of thymol. These formulations have potential applications in the development of innovative and customized active packaging systems to increase the shelf-life of food products.Authors would like to thank Spanish Ministry of Economy and Competitiveness (MAT-2015-59242-C2-2-R) and Generalitat Valenciana (IDIFEDER/2018/007) for their support of this research. Marina Ramos would like to thank University of Alicante (Spain) for the UAFPU2011-48539721S predoctoral research grant

Controlled Release, Disintegration, Antioxidant, and Antimicrobial Properties of Poly (Lactic Acid)/Thymol/Nanoclay Composites

Nano-biocomposite films based on poly (lactic acid) (PLA) were prepared by adding thymol (8 wt.%) and a commercial montmorillonite (D43B) at different concentrations (2.5 and 5 wt.%). The antioxidant, antimicrobial, and disintegration properties of all films were determined. A kinetic study was carried out to evaluate the thymol release from the polymer matrix into ethanol 10% (v/v) as food simulant. The nanostructured networks formed in binary and ternary systems were of interest in controlling the release of thymol into the food simulant. The results indicated that the diffusion of thymol through the PLA matrix was influenced by the presence of the nanoclay. Disintegration tests demonstrated that the incorporation of both additives promoted the breakdown of the polymer matrix due to the presence of the reactive hydroxyl group in the thymol structure and ammonium groups in D43B. Active films containing thymol and D43B efficiently enhanced the antioxidant activity (inhibition values higher than 77%) of the nano-biocomposites. Finally, the addition of 8 wt.% thymol and 2.5 wt.% D43B significantly increased the antibacterial activity against Escherichia coli and Staphylococcus aureus 8325-4, resulting in a clear advantage to improve the shelf-life of perishable packaged food.Authors would like to thank Spanish Ministry of Economy and Competitiveness (MAT2017-84909-C2-1-R) and Generalitat Valenciana (IDIFEDER/2018/007) for their support of this research. Marina Ramos would like to thank University of Alicante (Spain) for the UAFPU2011-48539721S predoctoral research grant. AJMV thanks ´Coimbra Chemistry Center and Fundação para a Ciência e Tecnologia (FCT) for the financial support through the programmes UID/QUI/UI0313/2020 and COMPETE

Characterization and disintegrability under composting conditions of PLA-based nanocomposite films with thymol and silver nanoparticles

Active nanocomposite films based on poly(lactic acid) (PLA), thymol and silver nanoparticles (Ag-NPs) were prepared and characterized. PLA films containing 6 and 8 wt% thymol and 1 wt% Ag-NPs were processed by extrusion to obtain binary and ternary formulations. The addition of thymol and Ag-NPs modified the PLA thermal, optical and barrier properties; in particular water vapour permeability (WVP), maintaining oxygen transmission rate (OTR) values unchanged. Homogeneous surfaces in all films were obtained as proved by FESEM micrographs. The presence of the active additives enhanced the disintegration rate of PLA under composting conditions, which was completed in 14 days. Results suggest that these nanocomposite films could be considered promising degradable active packaging materials with low environmental impact.Authors would like to thank Spanish Ministry of Economy and Competitiveness for financial support (MAT-2015-59242-C2-2-R). Marina Ramos would like to thank University of Alicante (Spain) for UAFPU2011-48539721S pre-doctoral research grant

Effect of Exposure to Seminal Plasma Through Natural Mating in Cattle on Conceptus Length and Gene Expression

peer-reviewedA growing body of evidence suggests that paternal factors have an impact on offspring development. These studies have been mainly carried out in mice, where seminal plasma (SP) has been shown to regulate endometrial gene expression and impact embryo development and subsequent offspring health. In cattle, infusion of SP into the uterus also induces changes in endometrial gene expression, however, evidence for an effect of SP on early embryo development is lacking. In addition, during natural mating, the bull ejaculates in the vagina; hence, it is not clear whether any SP reaches the uterus in this species. Thus, the aim of the present study was to determine whether SP exposure leads to improved early embryo survival and developmental rates in cattle. To this end, Day 7 in vitro produced blastocysts were transferred to heifers (12–15 per heifer) previously mated to vasectomized bulls (n = 13 heifers) or left unmated (n = 12 heifers; control). At Day 14, heifers were slaughtered, and conceptuses were recovered to assess size, morphology and expression of candidate genes involved in different developmental pathways. Additionally, CL volume at Day 7, and weight and volume of CL at Day 14 were recorded. No effect of SP on CL volume and weight not on conceptus recovery rate was observed. However, filamentous conceptuses recovered from SP-exposed heifers were longer in comparison to the control group and differed in expression of CALM1, CITED1, DLD, HNRNPDL, PTGS2, and TGFB3. In conclusion, data indicate that female exposure to SP during natural mating can affect conceptus development in cattle. This is probably achieved through modulation of the female reproductive environment at the time of mating. Keywords: seminal plasma, embryo development, corpus luteu

Las garantías convencionales y constitucionales del derecho penal y procesal penal

El problema surge en determinar cuál es el conjunto de garantías convencionales y constitucionales (compatibles con las primeras) que permiten configurar el orden jurídico legítimo mínimo para un Derecho Penal y Procesal Penal compatible con la visión antropológica surgida a partir de las Declaraciones y Convenciones sobre Derechos Humanos, y el modelo iusfilosófico y político dominante contenido en la cláusula del Estado Social y Democrático de Derecho. Además de sus consecuencias dogmáticas y hermenéuticas sobre la configuración del Sistema Penal y Procesal Penal colombiano.Universidad Libre -- Facultad de Derecho y Ciencias Políticas -- Derecho penal, derecho disciplinario y derechos humano