Co-non-solvency: Mean-field polymer theory does not describe polymer collapse transition in a mixture of two competing good solvents

Smart polymers are a modern class of polymeric materials that often exhibit unpredictable behavior in mixtures of solvents. One such phenomenon is co-non-solvency. Co-non-solvency occurs when two (perfectly) miscible and competing good solvents, for a given polymer, are mixed together. As a result, the same polymer collapses into a compact globule within intermediate mixing ratios. More interestingly, polymer collapses when the solvent quality remains good and even gets increasingly better by the addition of the better cosolvent. This is a puzzling phenomenon that is driven by strong local concentration fluctuations. Because of the discrete particle based nature of the interactions, Flory-Huggins type mean field arguments become unsuitable. In this work, we extend the analysis of the co-non-solvency effect presented earlier [Nature Communications 5, 4882 (2014)]. We explain why co-non-solvency is a generic phenomenon that can be understood by the thermodynamic treatment of the competitive displacement of (co)solvent components. This competition can result in a polymer collapse upon improvement of the solvent quality. Specific chemical details are not required to understand these complex conformational transitions. Therefore, a broad range of polymers are expected to exhibit similar reentrant coil-globule-coil transitions in competing good solvents

Self-avoiding walks on scale-free networks

Several kinds of walks on complex networks are currently used to analyze search and navigation in different systems. Many analytical and computational results are known for random walks on such networks. Self-avoiding walks (SAWs) are expected to be more suitable than unrestricted random walks to explore various kinds of real-life networks. Here we study long-range properties of random SAWs on scale-free networks, characterized by a degree distribution $P(k) \sim k^{-\gamma}$. In the limit of large networks (system size $N \to \infty$), the average number $s_n$ of SAWs starting from a generic site increases as $\mu^n$, with $\mu = / - 1$. For finite $N$, $s_n$ is reduced due to the presence of loops in the network, which causes the emergence of attrition of the paths. For kinetic growth walks, the average maximum length, $$, increases as a power of the system size: $\sim N^{\alpha}$, with an exponent $\alpha$ increasing as the parameter $\gamma$ is raised. We discuss the dependence of $\alpha$ on the minimum allowed degree in the network. A similar power-law dependence is found for the mean self-intersection length of non-reversal random walks. Simulation results support our approximate analytical calculations.Comment: 9 pages, 7 figure

Using Chemical Modeling to Asses Water Quality in the Raigón Aquifer System in Southern Uruguay

The Raigón aquifer is an important groundwater system in southern Uruguay. The increasing use of groundwater resources in the last decades has provoked changes in the concentration of many elements which are strongly related to anthropogenic pollution sources. Concentration levels are useful to detect changes in reservoir status but it is also necessary to analyze their chemical significance in order to make an accurate assessment of the sources of contamination and the causes of changes. In this work we use the available thermodynamic data to calculate chemical speciation on these groundwater samples. Trace elements present as anions, in particular Se and Mo, are especially focused to show the chemical modeling possibilities. Both elements form anionic species, predominantly MoO42- and SeO42-. Results show that these anions interact in solution and are greatly influenced by the concentration of the abundant calcium ion. Localized changes in pH can strongly affect the situation. The same is observed with the pE parameter, but only in the case of Se. Chemical speciation of trace elements is in general highly dependent on pH, pE and concentration of major elements. In consequence, for a fixed analytical total concentration, these parameters can markedly change the situation, affecting the mobility, the bioavailability and environmental fate of these elements. The strategy employed in this work can also be extended to the study of many other environmental water scenarios.The authors are grateful to CSIC (Programa de Apoyo a Grupos) and ANII (Project FCE_2011_6491), Uruguayan organizations, for financial support.Peer Reviewe

Using Chemical Modeling to Asses Water Quality in the Raigón Aquifer System in Southern Uruguay

The Raigón aquifer is an important groundwater system in southern Uruguay. The increasing use of groundwater resources in the last decades has provoked changes in the concentration of many elements which are strongly related to anthropogenic pollution sources. Concentration levels are useful to detect changes in reservoir status but it is also necessary to analyze their chemical significance in order to make an accurate assessment of the sources of contamination and the causes of changes. In this work we use the available thermodynamic data to calculate chemical speciation on these groundwater samples. Trace elements present as anions, in particular Se and Mo, are especially focused to show the chemical modeling possibilities. Both elements form anionic species, predominantly MoO42- and SeO42-. Results show that these anions interact in solution and are greatly influenced by the concentration of the abundant calcium ion. Localized changes in pH can strongly affect the situation. The same is observed with the pE parameter, but only in the case of Se. Chemical speciation of trace elements is in general highly dependent on pH, pE and concentration of major elements. In consequence, for a fixed analytical total concentration, these parameters can markedly change the situation, affecting the mobility, the bioavailability and environmental fate of these elements. The strategy employed in this work can also be extended to the study of many other environmental water scenarios

Voltammetric characterization of [ReO]3+ containing complexes

In the present work, the voltammetric profiles of Au-pc in 1 mM solutions of K[ReVOCl2(L)] (L = dianions of H2hida or H2eida; hida, n-(2,6-dimethylphenyl carbamoylmethyl)imino diacetic acid, and eida, 2,6-diethyl ida) complexes were evaluated. The obtained electrochemical response was the result of the contributions coming from the [ReO]3+ core (Epa at ca. 0.2 V vs. Ag/AgNO3) and the carboxylic group of the ligand. There where also observed redox contributions ascribed to the presence of perrhenate coming from the decomposition of the complex with the lost of ligands, in agreement with the low stability of the studied complexes. copyright The Electrochemical Society.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

Alergia à proteína do leite de vaca, qualidade de vida e estilos parentais

Introduction: Cow’s milk protein allergy requires changes in family habits to maintain children’s health. Objective: This study evaluated the effects of cow’s milk protein allergy on the health of children, the quality of life of parents and children, and the adopted parental styles. Methods: Control case study. The case group consisted of children with cow’s milk protein allergy, from eight months to five years old, and those guardians, and the Control Group, for healthy children of the same age group, and their parents. The quality of life of the child (TNO-AZL Preschool Children Quality of Life) and the caregiver (SF-36) were evaluated; parental style (Parental Beliefs and Care Practices Scale); and socioeconomic and health data of the child. The Mann-Whitney test was used to compare the groups (p <0.05). Results: 76 dyads from the case group and 44 from the control group participated. Children with cow’s milk protein allergy had a lower quality of life in the health dimension, worse nutritional status, followed up with a larger number of health professionals. Those in charge of the case group offered less body stimulation to the children. Those in the control group had a lower quality of emotional life. Conclusions: Cow’s milk protein allergy had an impact on the health and nutritional status of children, on the corporal stimulation received by the children, and on the quality of emotional life of those guardians.Introdução: A alergia à proteína do leite de vaca requer alterações dos hábitos familiares para manutenção das condições de saúde das crianças. Objetivo: Este estudo analisou os efeitos da alergia à proteína do leite de vaca sobre a saúde de crianças, qualidade de vida de responsáveis e crianças e sobre os estilos parentais adotados. Método: Estudo caso controle. O grupo caso foi constituído por crianças com alergia à proteína do leite de vaca, de oito meses a cinco anos de idade, e seus responsáveis, e o Grupo Controle, por crianças saudáveis, de mesma faixa etária, e seus responsáveis. Foram avaliadas a qualidade de vida da criança (TNO-AZL Preschool Children Quality of Life) e do responsável (SF-36); estilo parental (Escala de Crenças Parentais e Práticas de Cuidado); e dados socioeconômicos e de saúde da criança. O teste de Mann-Whitney foi utilizado para comparar os grupos (p <0,05). Resultados: Participaram 26 díades do grupo caso e 44 do grupo controle. Crianças com alergia proteína do leite de vaca apresentaram menor qualidade de vida na dimensão saúde, pior estado nutricional, realizaram acompanhamento com maior número de profissionais da saúde. Os responsáveis do grupo caso ofereceram menor estimulação corporal às crianças. Responsáveis do grupo controle apresentaram menor qualidade de vida emocional. Conclusão: A alergia à proteína do leite de vaca impactou na saúde e no estado nutricional das crianças, na estimulação corporal recebida pelas crianças, e na qualidade de vida emocional dos responsáveis

Anticuerpos monoclonales que se unen a la hormona del crecimiento humana (hGH)

Traducción de Patente Europea E97916700 (fecha de solicitud, 27/03/1997).-- Prioridad: SE199603299601231.-- Titulares: Pharmacia Spain S.A., Consejo Superior de Investigaciones Científicas (CSIC).La invención se refiere a anticuerpos monoclonales capaces de unirse específicamente a la variante de la hormona de crecimiento humana de peso molecular 20kda. Dicho anticuerpo monoclonal no presenta prácticamente unión a la hgh de 22 kda. La invención se refiere asimismo a la utilización de dicho anticuerpo monoclonal para la medición de la hgh de 20 k, especialmente en fluídos corporales. Los anticuerpos descritos se pueden emplear en la detección y cuantificación de hgh de 20k, especialmente en el suero.Peer reviewe

Nonsense mediated mRNA decay affects nonsense transcripts levelsand in vitro response to gentamicin and ataluren in X-ALD

1 p.Fil: Amorosi, CA. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Hospital de Niños de la Santísima Trinidad. Centro de Estudio de las Metabolopatías Congénitas; Argentina.Fil: Kemp, Stephan. Universidad de Amsterdan; Netherlands.Fil: : Dodelson de Kremer, Raquel. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Hospital de Niños de la Santísima Trinidad. Centro de Estudio de las Metabolopatías Congénitas; Argentina.Fil: Argaraña, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina.Fil: Ramirez Oller, Ana María. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Hospital de Niños de la Santísima Trinidad. Centro de Estudio de las Metabolopatías Congénitas; Argentina.Background: X-linked adrenoleukodystrophy (X-ALD) is caused by mutations in the ABCD1 gene, characterized by increased concentrations of very long-chain fatty acids due to a defect in peroxisomal β-oxidation. Aminoglycosides and PTC124 can readthrough premature termination codons (PTCs), allowing the translation of full length proteins. Response to drugs found only in patients with the higher level of mRNA. Nonsense-mediated mRNA decay (NMD) is a mechanism, which degrades transcripts carrying PTCs and has an important role in response to treatments to promote readthrough. UPF1 RNA helicase are involved in this pathway. Objetives: Prove aminoglycosides and PTC124 in fibroblast cultures from patients with X-ALD. Analyze NMD efficiency in X-ALD fibroblasts. Materials and Methods: Fibroblasts from patients (p.Trp137*, p.Ser290*, p.Arg464*) were treated with different doses of gentamicin and PTC124. Protein expression was analyzed by Western blot. NMD was directly inhibited by using siRNA against UPF1 and indirectly by Cicloheximide. Levels of mRNA were determined by qPCR. * The study was approved by Comité Institucional de Etica para la Investigación Clínica (CIEIS) Polo Hospitalario, Provincia de Córdoba. * This work was supported by Fundación Florencio Fiorini , SECyT-UNC, PICT-FONCYThttps://onlinelibrary.wiley.com/doi/epdf/10.1007/s10545-013-9633-zFil: Amorosi, CA. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Hospital de Niños de la Santísima Trinidad. Centro de Estudio de las Metabolopatías Congénitas; Argentina.Fil: Kemp, Stephan. Universidad de Amsterdan; Netherlands.Fil: : Dodelson de Kremer, Raquel. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Hospital de Niños de la Santísima Trinidad. Centro de Estudio de las Metabolopatías Congénitas; Argentina.Fil: Argaraña, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina.Fil: Ramirez Oller, Ana María. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Hospital de Niños de la Santísima Trinidad. Centro de Estudio de las Metabolopatías Congénitas; Argentina.Bioquímica y Biología Molecular (ídem 1.6.3

Os pecados e os prazeres terrenos no Jardim das Delícias de Bosch

Neste estudo objetivamos compreender as relações entre as descrições e as representações de Paraíso e Inferno e sua presença na obra de Hieronymus Bosch. Considerado um dos grandes pintores do final do medievo, Bosch retratou importantes aspectos do imaginário do período entre os séculos XV e XVI. Neste contexto, interessa-nos identificar as permanências da mentalidade medieval no seu tríptico a óleo, O Jardim das Delícias, visto que muitos dos elementos existentes nesta obra baseiam-se em pinturas, textos literários e eclesiásticos conhecidos por seus contemporâneos, acrescidos de simbologias próprias. Utilizamos por metodologia a pesquisa bibliográfica e a análise de imagem

A INFÂNCIA NA IDADE MÉDIA (SÉC. XIV AO XVI): DISCUSSÕES PERTINENTES

The focus of this analysis is concentrated in some aspects related to the way the medieval childhood appears on the current historiography and the representation of children in some works of the Flemish painter Pieter Bruegel, the Elder. The study of Childhood History, in spite of recent, mixes speeches from many knowledge areas and tense argues. The History process witch involves this concept includes issues that go beyond the biological factors depending on the context and conditions of the sociocultural, considering the productions discourse and the social place gave to childhood in different eras. The bibliographic research has been used as methodology, aimed with the historiographical debate and the analysis of image. The objective is pointing different analyses about the conceptions of the presence or absence of “the sense of childhood” in the Middle Age. The importance of the discussion about the Medieval Childhood is not placed on search the truth in each argument but in polyphonic discourse, which crosses, in differing conceptions of childhood, or the way children are perceived and placed on societies.O enfoque dessa análise está concentrado em alguns aspectos relacionados à forma como a infância medieval é apresentada na historiografia atual e a representação de crianças em algumas obras do pintor flamengo Pieter Bruegel, o Velho. O estudo da História da infância, apesar de recente, envolve discursos de muitas áreas de conhecimento e discussões acirradas. O processo histórico que envolve este conceito inclui questões que vão além dos fatores biológicos, dependendo do contexto e das condições sócio-culturais, e considerando a produção discursiva e os lugares sociais atribuídos à infância em diferentes épocas. Utilizou-se por metodologia a pesquisa bibliográfica visando o debate historiográfico e a análise de imagem. Busca-se apontar diferentes análises sobre as concepções da presença ou ausência do “sentimento de infância” na Idade Média. A importância da discussão a respeito da infância medieval não está localizada na busca de veracidade em cada argumentação, mas na polifonia discursiva que atravessa, diferindo nas concepções de infância, ou seja, a forma como as crianças são percebidas e inseridas nas sociedades