Environmentally Relevant Concentrations of 17α-Ethinylestradiol (EE2) Interfere With the Growth Hormone (GH)/Insulin-Like Growth Factor (IGF)-I System in Developing Bony Fish

The aim of this study was to evaluate whether effects of environmental estrogens on fish growth and reproduction may be mediated via modulating the growth hormone (GH)/insulin-like growth factor I (IGF-I) system. To this end, developing male and female monosex populations of tilapia were exposed to 17α-ethinylestradiol (EE2) at 5 and 25 ng EE2/l water from 10-day postfertilization (DPF) until 100 DPF. Under exposure to both EE2 concentrations, sex ratio shifted toward more females and body length, and weight were significantly reduced in males. The growth-reducing effect was associated with significant changes in hepatic IGF-I expression, both in males and females and with significant alterations of IGF-I mRNA and GH mRNA in the brain. The changes in IGF-I and GH mRNA were accompanied by altered estrogen receptor α (ERα) expression in brain and liver. These findings point to an influence of estrogenic exposure on the endocrine GH/IGF-I axis. In addition, the EE2 treatment resulted in significant changes of ERα and IGF-I expression in ovaries and testis, suggesting that the estrogens interact not only with the endocrine but also with the autocrine/paracrine part of the IGF-I system. Overall, our results provide evidence that EE2 at environmentally relevant concentrations is able to interfere with the GH/IGF-I system in bony fish and that the impairing effects of estrogens reported on fish growth and reproductive functions may rather result from a cross talk between the sex steroid and the IGF-I system than be toxicologica

Modification of poly(vinyl chloride) with new aromatic thiol compounds. Synthesis and characterization

Different thiol compounds were tested for the synthesis of poly(vinyl chloride) (PVC) with halogen groups and the course of the modification reactions followed under different conditions by NMR spectroscopy and elemental analysis. It is shown that PVC can be modified without side reactions using 4-fluorothiophenol, 4-chlorothiophenol, 4-bromothiophenol, 3,4-di-fluorothiophenol, penta-fluorothiophenol and pentachlorothiophenol. The reactivities and final degrees of modification of the different nucleophiles are compared showing that, when the thiolate salt is preformed, the bromine derivative reacts quicker and higher degrees of modification are reached than with its smaller homologues. On the other hand, using the thiol compounds in combination with potassium carbonate this order is inverted and highest degrees of modification are achieved with 4-fluorothiophenol. Glass transition temperatures and thermal stabilities of the new compounds are compared.Fil: Navarro, Rodrigo. Instituto en Ciencia y Tecnología de Polímeros; EspañaFil: Bierbrauer, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Mijangos, Carmen. Instituto en Ciencia y Tecnología de Polímeros; EspañaFil: Goiti, Eunate. Instituto en Ciencia y Tecnología de Polímeros; EspañaFil: Reinecke, Helmut. Instituto en Ciencia y Tecnología de Polímeros; Españ

Opening new gates for the modification of PVC or other PVC derivatives: Synthetic strategies for the covalent binding of molecules to PVC

Several synthetic strategies based on the use of substituted aromatic and hetero-aromatic thiols for the covalent binding of modifier compounds to PVC are described. A variety of aliphatic alcohols and amines are linked to the aromatic or heteroaromatic rings via highly active functionalities as the isocyanate, acidchloride, or chlorosulfonyl group, and the three chlorine atoms of trichlorotriazine. The first three pathways lead to protected aromatic disulfides obtaining the substituted aromatic thiols by reduction as a final step of an unprecedented synthetic route. The second approach, in a novel, extremely efficient, and scalable process, uses the particular selectivity of trichlorotriazine to connect aliphatic amines, alcohols, and thiols to the ring and creates the thiol via nucleophilic substitution of a heteroaromatic halogen by thiourea and subsequent hydrolysis. Most of the modifier compounds were linked to the polymer chains with high degrees of anchorage. The presented approaches are highly versatile as different activations of aromatic and heteroaromatic rings are used. Therefore, many types of tailored functional nucleophiles may be anchored to PVC providing non-migrating materials with a broad range of applications and properties.The authors gratefully acknowledge support from Grant MAT 2013-42957-R. Rodrigo Navarro gratefully acknowledges funding from the Spanish Research Council (CSIC) and European Social Fund (ESF) through the JAE-doc program.Peer Reviewe

General approach to prepare polymers bearing pendant isocyanate groups

A versatile synthetic approach for the easy preparation, under smooth reaction conditions, of diverse classes of linear polymers bearing aliphatic or aromatic isocyanate groups in the side chains is described. The procedure consists in the transformation of primary amine groups present in the polymer into isocyanates using equimolar amounts of diphosgene or triphosgene and a soluble tertiary amine as the acid scavenger. The transformation of all amine groups takes place quasi-simultaneously and instantaneously as shown by the invariability of the chain length of the polymer and the absence of crosslinked products. The number of isocyanate groups per molecule that can be achieved by this approach corresponds to the number of primary amine groups of the starting polymer and is up to three orders of magnitude higher than in any other non-crosslinked molecule described so far. The isocyanate functionalized polymers can be used to anchor a large variety of molecules to the polymer chains. The approach is in detail demonstrated with poly(vinyl chloride) (PVC) carrying aromatic amine groups but has also been confirmed by using a number of other polymer types bearing both aromatic and aliphatic primary amines. Furthermore, it has been used to prepare a novel low molecular weight compound, tris(2-cyanatoethyl)amine.The authors gratefully acknowledge support from Grants MAT2013-42957-R, and RTI2018-096636-J-I0

PRE-INTERVENTIONAL LEFT VENTRICULAR 2D STRAIN PREDICTS THE RECOVERY OF MYOCARDIAL DYSFUNCTION AND IMPROVEMENT IN FUNCTIONAL CAPACITY AFTER TRANSCATHETER AORTIC VALVE IMPLANTATION

International audienceAn extended literature analyzes the accumulation foreign exchange holding observed in many developing and emerging countries since the 2000s. Empirical studies on the self-insurance motive suggest that high-reserves economies are more resilient to financial crises and to international capital inflows volatility. They show also that pre-crisis foreign reserve accumulation explains post-crisis growth. However, some papers suggest that the relationship between international reserves holding and reduced vulnerability is nonlinear, meaning that reserve holding is subject to diminishing returns. This paper devotes more attention to the potential nonlinear relationship between the foreign reserves holding and macroeconomic resilience to shocks. For a sample of 9 emerging economies, we assess to what extent the accumulation of international reserves allows to mitigate negative impacts of external shocks on the output gap. While a major part of the literature focuses on the global financial crisis, we investigate this question by considering two sub-periods: 1995-2003 and 2004-2013. We implement threshold VAR (TVAR) model in which the structure is allow to change if the threshold variable crosses a certain estimated threshold. We find that the effectiveness of reserve holding to improve the resilience of domestic economies to shocks has increased over time. Hence, the diminishing returns of foreign reserve holding stressed in the previous literature must be qualified

Technological advances in fibrin for tissue engineering

Fibrin is a promising natural polymer that is widely used for diverse applications, such as hemostatic glue, carrier for drug and cell delivery, and matrix for tissue engineering. Despite the significant advances in the use of fibrin for bioengineering and biomedical applications, some of its characteristics must be improved for suitability for general use. For example, fibrin hydrogels tend to shrink and degrade quickly after polymerization, particularly when they contain embedded cells. In addition, their poor mechanical properties and batch-to-batch variability affect their handling, long-term stability, standardization, and reliability. One of the most widely used approaches to improve their properties has been modification of the structure and composition of fibrin hydrogels. In this review, recent advances in composite fibrin scaffolds, chemically modified fibrin hydrogels, interpenetrated polymer network (IPN) hydrogels composed of fibrin and other synthetic or natural polymers are critically reviewed, focusing on their use for tissue engineering.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported by Programa de Actividades de I + D entre Grupos de Investigación de la Comunidad de Madrid, S2018/BAA-4480, Biopieltec-CM, Programa Estatal de I + D + i Orientada a los Retos de la Sociedad, RTI2018-101627-B-I00, Proyectos de Generación de Conocimiento 2021, PID2021-126523OB-I00, Proyectos en colaboración público-privada 2021, CPP2021-008396, LOLICOMB Project, PID2020-116439GB-I00 and Cátedra Fundación Ramón Areces. Grant PID2021-126523OB-I00 funded by MCIN/AEI/10.13039/501100011033 and, as appropriate, by “ERDF A way of making Europe.” Grant CPP2021-008396 funded by MCIN/AEI/ 10.13039/501100011033 and by the European Union “NextGenerationEU/PRTR.”Publicad

Hidrogeles multicomponentes basados en vinilpirrolidona y su aplicación en ingeniería de tejidos y/o medicina regenerativa

Hidrogel con estructura de red polimérica multicomponente entrecruzada, caracterizado porque comprende: a) unidades derivadas de vinilpirrolidona (V) y unidades derivadas de un monómero alquénico aniónico o anionizable (A), donde las relaciones de reactividad en copolimerización radical binaria de (V) y (A) tienen valores máximo y mínimo de 0.5 respectivamente; y b) unidades derivadas de al menos un entrecruzante; siempre que el o los entrecruzantes sean i) dos entrecruzantes E1 y E2, donde E1 presenta homología al menos parcial respecto a (A) y E2 presenta homología al menos parcial respecto a (V); o ii) un entrecruzante E3 que presenta homología respecto a (A) y (V). Procedimiento de obtención del mencionado hidrogel que comprende poner en contacto los monómeros (A) y (V) con los entrecruzantes E1 y E2, o el entrecruzante E3, en condiciones de polimerización radicalaria. Uso del hidrogel en aplicaciones biológicas, biomédicas o biotecnológicas que requieran una interacción no tóxica hidrogel-célula.Peer reviewedConsejo Superior de investigaciones Científicas, Universidad Complutense de MadridB1 Patente sin examen previ

New Insights in the Synthesis of High-Molecular-Weight Aromatic Polyamides-Improved Synthesis of Rod-like PPTA

Producción CientíficaBy employing a variation of the polyamidation method using in situ silylated diamines and acid chlorides, it was possible to obtain a rod-type polyamide: poly(p-phenylene terephthalamide) (PPTA, a polymer used in the high-value-added material Kevlar), with a molecular weight much higher than that obtained with the classical and industrial polyamidation method. The optimization of the method has consisted of using, together with the silylating agent, a mixture of pyridine and a high-pKa tertiary amine. The research was complemented by a combination of nuclear magnetic resonance and molecular simulation studies, which determined that the improvements in molecular weight derive mainly from the formation of silylamide groups in the growing polymer

Разработка эффективных центраторов обсадной колонны

Основной целью работы является разработка эффективных центраторов обсадной колонны. Для выполнения поставленной цели рассмотрены основные решаемые задачи: 1 Провести обзор сортамента центраторов обсадных колонн различных производителей. 2 Провести патентный обзор центраторов обсадных колонн. 3 Провести анализ, существующих центраторов и разработать эффективный центратор обсадной колонны, лишенный недостатков, выделенных в анализе. Также выполнены разделы "Социальная ответственность" и "Производственный менеджмент, ресурсоэффективность и ресурсосбережение".The main goal of the work is to develop efficient casing centralizers. To accomplish this goal, the main tasks are addressed: 1 Review the range of casing centralizers from different manufacturers. 2 Conduct a patent review of casing centralizers. 3 Carry out an analysis of existing centralizers and develop an effective casing centering device that is free from the weaknesses highlighted in the analysis. Also the sections "Social Responsibility" and "Production Management, Resource Efficiency and Resource Saving"