Recovery of recycled acrylonitrile-butadiene-styrene, through mixing with styrene-ethylene/butylene-styrene

Recovery of recycled acrylonitrile-butadiene-styrene (ABS) through mixing with styrene-ethylene/butylene-styrene (SEBS) has been studied in this paper. To simulate recycled ABS, virgin ABS was processed through 5 cycles, at extreme processing temperatures, 220 degrees C and 260 degrees C. The virgin ABS, the virgin SEBS, the recycled ABS and the mixtures were mechanically, thermally and rheologically characterized after the various cycles of reprocessing in order to evaluate their corresponding properties and correlate them with the number of cycles undergone. With these data and using Computer Aided Engineering (CAE) the injection process was simulated by obtaining the optimal injection process parameters. Mixtures were injected at two temperatures in a sensorised mold correlating the shrinkage of the parts with temperature. The results show that tensile strength of ABS remains practically constant as the number of reprocessing cycles increases, while in the material injected with SEBS the tensile strength decreases. Concerning the Charpy notched impact strength; the values of the ABS reprocessed at 220 degrees C remain more or less unchanged, while the values for 260 C show a significant decrease. The adhesion of the SEBS causes, in both cases, an increase in impact strength. DSC techniques enabled us to observe how the glass transition temperature (T-g) remains more or less constant regardless of the number of cycles or the temperature, whereas the crosslinking is much greater in the samples reprocessed at 260 C. Finally, the viscosity decreases with each cycle and this decrease becomes even more noticeable with the addition of SEBS, and also that the parts molded at lower temperatures have less shrinkage. (c) 2013 Elsevier B.V. All rights reserved.We would like to thank the Vice-Directorate of Research, Development and Innovation of the Polytechnic University of Valencia for the help granted to the project: "Ternary systems research applied to polymeric materials for the upgrading of waste styrene", Ref: 20091056 within the program of First Projects of Investigation (PAID 06-09) where this work is framed.Peydro, MA.; Parres, F.; Crespo Amorós, JE.; Navarro Vidal, R. (2013). Recovery of recycled acrylonitrile-butadiene-styrene, through mixing with styrene-ethylene/butylene-styrene. Journal of Materials Processing Technology. 213(8):1268-1283. https://doi.org/10.1016/j.jmatprotec.2013.02.012S12681283213

Estructura de un bosque natural perturbado de Pinus tropicalis Morelet en Galalón, Cuba

"Los bosques naturales de Pinus tropicalis Morelet en Cuba han sido alterados por prácticas inadecuadas de aprovechamiento forestal. Esta investigación tiene el objetivo de caracterizar la estructura de un bosque perturbado de Pinus tropicalis en Galalón, Pinar del Río. Para ello se realizó un inventario florístico, se determinaron los índices de valor de importancia ecológica y de importancia ecológica ampliado. Se calculó la diversidad alfa mediante el recíproco del índice de Simpson (1/D) y el índice de Jackknife, así como la diversidad beta por medio de Morisita-Horn y Jaccard. Se evaluó el grado de perturbación del área mediante indicadores de cambios en el ecosistema. Se identificaron un total 22 familias, 30 géneros y 31 especies. Los parámetros estructurales indicaron que las especies de mayor importancia ecológica son P. tropicalis, P. caribaea var. caribaea y Byrsonima crassifolia. La diversidad florística se calificó de baja y la similitud resultó en tres grupos diferenciados por su composición florística.""Natural forests of Pinus tropicalis Morelet in Cuba have been altered by inadequate management. The aim of this study was to characterize the structure of a disturbed forest of Pinus tropicalis in Galalón, Pinar del Rio. We carried out a floristic inventory, and determined the ecological importance value and the increased ecological importance index. The alpha diversity was calculated by means of the reciprocal of the Simpson index (1/D) and the Jackknife index. The beta diversity was estimated through the Morisita-Horn and Jaccard. The degree of interference of the area was evaluated by means of indicators of changes in the ecosystem. We identified 30 genera and 31 species from 22 families. The structural parameters indicated that the species of higher ecological importance were P. tropicalis, P. caribaea var. caribaea and Byrsonima crassifolia. The floristic diversity was low and the similarity indexes yielded three groups differing in floristic composition.

Aplicación de un índice de calidad del agua (ICA) en la cuenca del río Ayuquila-Armería en México

Background. The water quality index (ICA) is a practical and useful tool to estimate the quality of water bodies, this method has been used in many countries. Goals. Evaluate the water quality of the Ayuquila-Armería river basin, based on two categories of possible use of the water resource, use in agricultural irrigation, protection of aquatic life and drinking use. Methods. The analysis of physical and chemical variables, analysis of heavy metals and nutrients and the characterization of anions and cations were carried out; In addition, the variables were complemented with the use of a biotic integrity index based on families of aquatic macroinvertebrates, to estimate organic contamination and the determination of fecal coliforms, in the forty sampling sites along the upper, middle, and lower part. of the basin. Results. Of the forty sites, the quality of the water for use in agricultural irrigation presented ICA ranges of regular (35%), good (27.5%) and excellent (37.5%) conditions. Regarding the comparison made for the quality of water for the protection of aquatic life and drinking use, it was found that eight sites (44.4%) present poor-quality conditions, another eight sites (44.4%) present good quality and only two sites (11.11%) an excellent quality condition. Conclusions. For the use of water in agricultural irrigation, there is no site that presents poor quality of the resource, in addition, by using different parameters related to agriculture, it can be ensured that there is no risk of loss or damage to crops by using water for irrigation. In the case of water quality in terms of the protection of aquatic life and potable use, in general the basin presents poor conditions. In this sense, aquatic organisms are sufferingAntecedentes. El índice de calidad del agua (ICA) es una herramienta práctica y útil para estimar la calidad de los cuerpos de agua, este método se ha utilizado en muchos países. Objetivos. Evaluar la calidad del agua de la cuenca del río Ayuquila-Armería, con base en dos categorías de posible uso del recurso agua, uso en riego agrícola, protección de la vida acuática y uso potable. Métodos. Se realizó el análisis de variables físicas y químicas, análisis de metales pesados y nutrientes y la caracterización de aniones y cationes; además se complementaron las variables con la utilización de un índice de integridad biótica basado en familias de macroinvertebrados acuáticos, para estimar la contaminación orgánica y la determinación de coliformes fecales, en los cuarenta sitios de muestreo a lo largo de la parte alta, media y baja de la cuenca. Resultados. De los cuarenta sitios, la calidad del agua para uso en riego agrícola presento rangos del ICA de condiciones regulares (35%), buenas (27.5%) y excelentes (37.5 %). En cuanto a la comparación realizada para la calidad del agua para protección de la vida acuática y uso potable, se encontró que ocho sitios (44.4%) presenta condiciones de mala calidad, otros ocho sitios (44.4%) presentan buena calidad y solo dos sitios (11.11%) una condición de calidad excelente. Conclusiones. Para el uso de agua en riego agrícola no se encuentra ningún sitio que presente mala calidad del recurso, además mediante la utilización de diferentes parámetros relacionados con la agricultura se puede asegurar que no existe riesgo de pérdida o daño en cultivos por utilizar el agua para irrigación. Para el caso de la calidad del agua en cuanto a la protección de la vida acuática y uso potable, en general la cuenca presenta malas condiciones. En este sentido los organismos acuáticos están sufriendo afectaciones tanto en su hábitat como en las condiciones fisicoquímicas que pueden menguar sus poblaciones, por otra parte, las comunidades humanas cercanas a los cauces hídricos serán más susceptibles a tener problemas relacionados con la salud

Deep-sequencing reveals broad subtype-specific HCV resistance mutations associated with treatment failure

A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) a-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of “extra-target” RAS suggests the need for RAS screening in all three DAA target regions

Bacteria-inducing legume nodules involved in the improvement of plant growth, health and nutrition

Bacteria-inducing legume nodules are known as rhizobia and belong to the class Alphaproteobacteria and Betaproteobacteria. They promote the growth and nutrition of their respective legume hosts through atmospheric nitrogen fixation which takes place in the nodules induced in their roots or stems. In addition, rhizobia have other plant growth-promoting mechanisms, mainly solubilization of phosphate and production of indoleacetic acid, ACC deaminase and siderophores. Some of these mechanisms have been reported for strains of rhizobia which are also able to promote the growth of several nonlegumes, such as cereals, oilseeds and vegetables. Less studied are the mechanisms that have the rhizobia to promote the plant health; however, these bacteria are able to exert biocontrol of some phytopathogens and to induce the plant resistance. In this chapter, we revised the available data about the ability of the legume nodule-inducing bacteria for improving the plant growth, health and nutrition of both legumes and nonlegumes. These data showed that rhizobia meet all the requirements of sustainable agriculture to be used as bio-inoculants allowing the total or partial replacement of chemicals used for fertilization or protection of crops

Captura de Desmodus rotundus em regiões de mata e manguezais do Estado do Maranhão: um estudo longitudinal

O presente trabalho teve por objetivos investigar o número de capturas e o controle do morcego hematófago Desmodus rotundus, em pequenas propriedades localizadas no município de Cedral no estado do Maranhão, que foi escolhido por ter sido efetuado o maior número de capturas do estado, sendo todas ao redor de currais. O controle oficial é realizado pela aplicação de pasta vampiricida de uso tópico a base de warfarina a 2%. Para o estudo foram utilizadas fichas de controle de morcegos hematófagos capturados em currais, como também, foi aplicado um questionário a campo para identificação dos locais com maior número de capturas. No período de 2005 a 2010 foram estudados os resultados de 223 buscas ativas por D. rotundus, em 101 propriedades. Foi capturado um total de 408 morcegos hematófagos, distribuídos em 190 das 223 buscas. Em todos os espécimes de D. rotundus capturados foi realizado o tratamento, que consistiu na aplicação da pasta vampiricida, no dorso do animal. Nas propriedades estudadas, verificou-se que dos 754 animais expostos, 344 foram agredidos. Destes, os bovinos foram a maior oferta de alimento aos Desmodus (49%), seguidos dos equídeos (18%), aves (15%), suínos (9%) e caprinos (8%). Apesar dos bovinos terem sido os mais atacados, em função do efetivo disponível, verificou-se uma preferência dos morcegos hematófagos por eqüídeos. As falhas nas capturas ocorreram onde havia poucos animais agredidos. Após análise de seis anos de realização do programa de controle com pasta vampiricida, verificou-se que a proporção de macho e fêmeas de D. rotundus capturados foi 1,08 machos para cada fêmea, o que demonstra que o tratamento foi mais efetivo nas fêmeas, uma vez que no primeiro ano do estudo, a proporção era de 1,21 fêmeas para cada macho. Verificou-se ainda que o controle foi realizado com sucesso em 95% das propriedades trabalhadas, com uma média de tempo de três anos de trabalho com até seis capturas por propriedade. Ao exame dos animais agredidos verificou-se que a área do pescoço dos grandes animais e dos caprinos são as mais atingidas, sugerindo o pouso direto dos morcegos sobre o animal. Uma representação pequena dos proprietários entrevistados vacinavam seus animais (57%), e destes apenas um fazia o reforço de vacinação. Concluiu-se que nas regiões de mangue e/ou matas, o controle foi efetivo nas capturas em currais, sendo prudente verificar a ocorrência de novas agressões, dentro de 15 dias e nos primeiros três meses. No planejamento de controle de D. rotundus em curral, deve ser considerado que o número de morcegos capturados é semelhante ao número de mordidas recentes. Em relação às criações domésticas de subsistências, D. rotundus se alimenta de fontes distintas, com uma menor predileção pelas aves

A supermatrix analysis of genomic, morphological, and paleontological data from crown Cetacea

<p>Abstract</p> <p>Background</p> <p>Cetacea (dolphins, porpoises, and whales) is a clade of aquatic species that includes the most massive, deepest diving, and largest brained mammals. Understanding the temporal pattern of diversification in the group as well as the evolution of cetacean anatomy and behavior requires a robust and well-resolved phylogenetic hypothesis. Although a large body of molecular data has accumulated over the past 20 years, DNA sequences of cetaceans have not been directly integrated with the rich, cetacean fossil record to reconcile discrepancies among molecular and morphological characters.</p> <p>Results</p> <p>We combined new nuclear DNA sequences, including segments of six genes (~2800 basepairs) from the functionally extinct Yangtze River dolphin, with an expanded morphological matrix and published genomic data. Diverse analyses of these data resolved the relationships of 74 taxa that represent all extant families and 11 extinct families of Cetacea. The resulting supermatrix (61,155 characters) and its sub-partitions were analyzed using parsimony methods. Bayesian and maximum likelihood (ML) searches were conducted on the molecular partition, and a molecular scaffold obtained from these searches was used to constrain a parsimony search of the morphological partition. Based on analysis of the supermatrix and model-based analyses of the molecular partition, we found overwhelming support for 15 extant clades. When extinct taxa are included, we recovered trees that are significantly correlated with the fossil record. These trees were used to reconstruct the timing of cetacean diversification and the evolution of characters shared by "river dolphins," a non-monophyletic set of species according to all of our phylogenetic analyses.</p> <p>Conclusions</p> <p>The parsimony analysis of the supermatrix and the analysis of morphology constrained to fit the ML/Bayesian molecular tree yielded broadly congruent phylogenetic hypotheses. In trees from both analyses, all Oligocene taxa included in our study fell outside crown Mysticeti and crown Odontoceti, suggesting that these two clades radiated in the late Oligocene or later, contra some recent molecular clock studies. Our trees also imply that many character states shared by river dolphins evolved in their oceanic ancestors, contradicting the hypothesis that these characters are convergent adaptations to fluvial habitats.</p

Antimicrobial de-escalation in the critically ill patient and assessment of clinical cure: the DIANA study

Purpose: The DIANA study aimed to evaluate how often antimicrobial de-escalation (ADE) of empirical treatment is performed in the intensive care unit (ICU) and to estimate the effect of ADE on clinical cure on day 7 following treatment initiation. Methods: Adult ICU patients receiving empirical antimicrobial therapy for bacterial infection were studied in a prospective observational study from October 2016 until May 2018. ADE was defined as (1) discontinuation of an antimicrobial in case of empirical combination therapy or (2) replacement of an antimicrobial with the intention to narrow the antimicrobial spectrum, within the first 3&nbsp;days of therapy. Inverse probability (IP) weighting was used to account for time-varying confounding when estimating the effect of ADE on clinical cure. Results: Overall, 1495 patients from 152 ICUs in 28 countries were studied. Combination therapy was prescribed in 50%, and carbapenems were prescribed in 26% of patients. Empirical therapy underwent ADE, no change and change other than ADE within the first 3&nbsp;days in 16%, 63% and 22%, respectively. Unadjusted mortality at day 28 was 15.8% in the ADE cohort and 19.4% in patients with no change [p = 0.27; RR 0.83 (95% CI 0.60\u20131.14)]. The IP-weighted relative risk estimate for clinical cure comparing ADE with no-ADE patients (no change or change other than ADE) was 1.37 (95% CI 1.14\u20131.64). Conclusion: ADE was infrequently applied in critically ill-infected patients. The observational effect estimate on clinical cure suggested no deleterious impact of ADE compared to no-ADE. However, residual confounding is likely