Is a low level of free thyroxine in the maternal circulation associated with altered endothelial function in gestational diabetes?

Synthesis of thyroid hormones, thyroxine (T4) and tri-iodothyronine (T3), in the human fetus starts from 17 to 19th weeks of gestation. Despite the majority of normal pregnant women reaching adequate levels of circulating thyroid hormones, in some cases, women with normal pregnancies have low level of free T4 during first trimester of pregnancy, suggesting that T4 action may be compromised in those women and their fetuses. In addition, pathological low levels of thyroid hormones are detected in isolated maternal hypothyroxemia (IMH) and clinical hypothyroidism. Nevertheless, human placenta regulates T3/T4 concentration in the fetal circulation by modulating the expression and activity of both thyroid hormone transporters (THT) and deiodinases. Then, placenta can control the availability of T3/T4 in the feto-placental circulation, and therefore may generate an adaptive response in cases where the mother courses with low levels of T4. In addition, T3/T4 might control vascular response in the placenta, in particularly endothelial cells may induce the synthesis and release of vasodilators such as nitric oxide (NO) or vasoconstrictors such as endothelin-1 mediated by these hormones. On the other hand, low levels of T4 have been associated with increase in gestational diabetes (GD) markers. Since GD is associated with impaired placental vascular function characterized by increased NO synthesis in placental arteries and veins, as well as elevated placental angiogenesis, it is unknown whether reduced T4 level at the maternal circulation could result in an altered placental endothelial function during GD. In this review, we analyze available information regarding thyroid hormones and endothelial dysfunction in GD; and propose that low maternal levels of T4 observed in GD may be compensated by increased placental availability of T3/T4 via elevation in the activity of THT and/or reduction in deiodinases in the feto-placental circulation

Cross talk between adipose tissue and placenta in obese and gestational diabetes mellitus pregnancies via exosomes

Obesity is an important public health issue worldwide, where it is commonly associated with the development of metabolic disorders, especially insulin resistance (IR). Maternal obesity is associated with an increased risk of pregnancy complications, especially gestational diabetes mellitus (GDM). Metabolism is a vital process for energy production and the maintenance of essential cellular functions. Excess energy storage is predominantly regulated by the adipose tissue. Primarily made up of adipocytes, adipose tissue acts as the body’s major energy reservoir. The role of adipose tissue, however, is not restricted to a “bag of fat.” The adipose tissue is an endocrine organ, secreting various adipokines, enzymes, growth factors, and hormones that take part in glucose and lipid metabolism. In obesity, the greater portion of the adipose tissue comprises fat, and there is increased pro-inflammatory cytokine secretion, macrophage infiltration, and reduced insulin sensitivity. Obesity contributes to systemic IR and its associated metabolic complications. Similar to adipose tissue, the placenta is also an endocrine organ. During pregnancy, the placenta secretes various molecules to maintain pregnancy physiology. In addition, the placenta plays an important role in metabolism and exchange of nutrients between mother and fetus. Inflammation at the placenta may contribute to the severity of maternal IR and her likelihood of developing GDM and may also mediate the adverse consequences of obesity and GDM on the fetus. Interestingly, studies on maternal insulin sensitivity and secretion of placental hormones have not shown a positive correlation between these phenomena. Recently, a great interest in the field of extracellular vesicles (EVs) has been observed in the literature. EVs are produced by a wide range of cells and are present in all biological fluids. EVs are involved in cell-to-cell communication. Recent evidence points to an association between adipose tissue-derived EVs and metabolic syndrome in obesity. In this review, we will discuss the changes in human placenta and adipose tissue in GDM and obesity and summarize the findings regarding the role of adipose tissue and placenta-derived EVs, with an emphasis on exosomes in obesity, and the contribution of obesity to the development of GDM

Role for Tetrahydrobiopterin in the Fetoplacental Endothelial Dysfunction in Maternal Supraphysiological Hypercholesterolemia

Maternal physiological hypercholesterolemia occurs during pregnancy, ensuring normal fetal development. In some cases, the maternal plasma cholesterol level increases to above this physiological range, leading to maternal supraphysiological hypercholesterolemia (MSPH). This condition results in endothelial dysfunction and atherosclerosis in the fetal and placental vasculature. The fetal and placental endothelial dysfunction is related to alterations in the L-arginine/nitric oxide (NO) pathway and the arginase/urea pathway and results in reduced NO production. The level of tetrahydrobiopterin (BH4), a cofactor for endothelial NO synthase (eNOS), is reduced in nonpregnant women who have hypercholesterolemia, which favors the generation of the superoxide anion rather than NO (from eNOS), causing endothelial dysfunction. However, it is unknown whether MSPH is associated with changes in the level or metabolism of BH4; as a result, eNOS function is not well understood. This review summarizes the available information on the potential link between MSPH and BH4 in causing human fetoplacental vascular endothelial dysfunction, which may be crucial for understanding the deleterious effects of MSPH on fetal growth and development

Assessment of natural radioactivity levels and radiation exposure in new building materials in Spain

Novel building materials were manufactured and analyzed for 226Ra, 232Th and 40K using an HPGe gamma-ray spectrometer. The results show that the highest value of 40K was 4530 Bq per kg which was measured in a sample containing fly ashes from olive stones. The highest values of 226Ra and 232Th activities were 181 and 185 Bq per kg, which were measured in a sample with fly ashes from the co-combustion of coal and coke, respectively. On the other hand, the lowest values of 40K, 226Ra and 232Th activities were obtained for samples incorporating mussel shells. The radiological health hazard parameters, such as radium equivalent activity (Raeq), activity concentration index (I), absorbed and effective dose rates, associated with these radionuclides were evaluated. These values are within the EU recommended limits in building materials, except for samples of concrete containing fly ashes from olive stones, coal and coke. This study has contributed to the inclusion of industrial wastes that have not been collected previously in the Naturally Occurring Radioactive Material (NORM) databases on radioactivity of building materials

Reciclado de residuos cerámicos en materiales absorbentes acústicos

The scope of this investigation is to develop a material mainly composed (80% w/w) of ceramic wastes that can be applied in the manufacture of road traffic noise reducing devices. The characterization of the product has been carried out attending to its acoustic, physical and mechanical properties, by measuring the sound absorption coefficient at normal incidence, the open void ratio, density and compressive strength. Since the sound absorbing behavior of a porous material is related to the size of the pores and the thickness of the specimen tested, the influence of the particle grain size of the ceramic waste and the thickness of the samples tested on the properties of the final product has been analyzed. The results obtained have been compared to a porous concrete made of crushed granite aggregate as a reference commercial material traditionally used in similar applications. Compositions with coarse particles showed greater sound absorption properties than compositions made with finer particles, besides presenting better sound absorption behavior than the reference porous concrete. Therefore, a ceramic waste-based porous concrete can be potentially recycled in the highway noise barriers field.El objetivo de este trabajo es desarrollar un material absorbente acústico compuesto fundamentalmente por residuos cerámicos (80% p) que se pueda utilizar en la fabricación de dispositivos reductores de ruido de carretera. La caracterización del producto se ha llevado a cabo atendiendo a sus propiedades acústicas, físicas y mecánicas, determinando el coeficiente de absorción acústica a incidencia normal, porosidad abierta, densidad y resistencia a compresión. La absorción acústica de un material poroso está fuertemente determinada por el tamaño de poro y por la longitud dela probeta sometida a ensayo. De este modo, se ha analizado la influencia del tamaño de partícula del residuo cerámico y del espesor de las muestras estudiadas en las propiedades del producto final. Los resultados obtenidos se han comparado con los obtenidos para un hormigón poroso elaborado con árido grueso, que se ha tomado como producto de referencia tradicionalmente empleado en este tipo de aplicaciones. Las composiciones elaboradas con el residuo de mayor tamaño de partícula han mostrado mayor absorción acústica, incluso mayor que las del hormigón poroso comercial. Por tanto, un hormigón poroso elaborado con residuos cerámicos puede ser potencialmente empleado como material en la fabricación de barreras acústicas de carretera

Amiloidosis Cardiaca por Cadenas Ligeras. Reporte de caso y aporte de la imagen multimodalidad en el diagnóstico.

Cardiac amyloidosis, considered previously as a rare disease, is now an illness to take into account in the diagnostic workup of patients with heart failure with preserved ejection fraction. The refinement of cardiac imaging techniques permits a timely diagnosis. There are clinical and imaging characteristics that orients into an etiology. We present a case of light chain cardiac amyloidosis, the clinical pearls that contributed to the diagnosis, and the systematic imaging workup.La amiloidosis cardiaca, antes considerada una enfermedad rara, es un padecimiento que debe tomarse en cuenta en el diagnóstico diferencial de los pacientes con insuficiencia cardiaca con fracción de expulsión preservada. El refinamiento de las técnicas de imagen cardiaca permite su diagnóstico oportuno. Existen ciertas características clínicas y de imagen que orientan hacia una posible etiología. Presentamos un caso de una paciente con amiloidosis por cadenas ligeras, las perlas clínicas que contribuyeron al diagnóstico, y el abordaje sistemático por imágenes

Generation of recommendations in an Augmented Reality system applied to tourism based on the context

Actualmente existen aplicaciones orientadas al turismo basadas en realidad aumentada, pero no integran técnicas de recomendación. Este artículo describe RAMCAT (Realidad Aumentada Móvil Contextual Aplicada al Turismo) un modelo de guía turística, que recomienda puntos de interés, teniendo en cuenta factores como preferencias personales y atributos contextuales. Se presentan los componentes teóricos de la arquitectura propuesta, así como sus características, destacando la integración de diferentes sistemas de recomendación, que permiten añadir nuevos motores en el futuro. El artículo se centra en describir sus funcionalidades y el módulo correspondiente al sistema de recomendación basado en el perfil del turista. Otra característica importante del sistema propuesto es la retroalimentación del mismo mediante calificaciones del turista y su trazabilidad.There are many tourist applications using augmented reality, but it’s necessary have models with open architecture to integrate different recommendation techniques. This paper describes RAMCAT, an adaptive tourist guide which recommended points of interest (POIs). Factors such as personal interests and context- -related attributes are important. We present the components of the proposed architecture and its characteristics, emphasizing the integration of different recommender systems, allowing adding new recommendation engine. The article describes with detail, the recommender system based on preferences of tourists. Other characteristic of the system is the feedback through qualifications of tourists and their traceability

Satellite images and geodetic measurements applied to the monitoring of the Horcones Inferior glacier, Mendoza, Argentina

This work analyzes the monitoring of the covered and regenerated Horcones Inferior Glacier (HIG) since the implementation of a semi-permanent GNSS station (HISS) on its surface during the summer seasons of 2009 and 2010. The glacier is located at 32° 41’s and 69° 57’w, at the foot of the south wall of Mt. Aconcagua, Aconcagua Provincial Park, Mendoza, Argentina. The average velocities obtained from the HISS station were of 1.3 cm/d and 3.5 cm/d during the 2009 and 2010 seasons respectively. The data procured using satellite images during the last surges (1984 and 2003) gave average velocities for the HIG front of 8.7 m/d for the first event and 11.5 m/d for the second one. These results allowed getting accurate and reliable movement tendency at the terminal part of the HIG during the 1984-2010 period.El presente trabajo realiza el monitoreo del glaciar Horcones Inferior, cubierto y regenerado a partir de la implementación de una estación GNSS semi-permanente (HISS), instalada sobre su superficie durante las temporadas de verano de 2009 y 2010 respectivamente. El glaciar se encuentra ubicado a los 32° 41’s y 69° 57’w, al pie de la pared sur del C° Aconcagua, en el Parque Provincial Aconcagua, Mendoza, Argentina. La estación HISS registró valores de velocidades medias de 1.3 cm/d y 3.5 cm/d durante las temporadas de 2009 y 2010. Se utilizaron imágenes satelitales para el seguimiento del frente del glaciar durante los últimos surges (1984 y 2003), cuyas velocidades medias fueron de 8.7 m/d para el primero y de 11.5 m/d para el segundo evento. Estos resultados permitieron obtener de manera precisa y confiable la tendencia de movimiento de la parte terminal del GHI durante el periodo 1984-2010.Asociación Argentina de Geofísicos y Geodesta

APLICACIÓN DE UN MODELO DE TEORÍA EVOLUTIVA DE JUEGOS EN PROCESOS DE COOPERACIÓN - Application of a model of evolutionary theory of games in cooperation processes

Este artículo es un acercamiento de los métodos computacionales de la complejidad, más exactamente de la teoría evolutiva de juegos, a los procesos de cooperación humana. Para ello, se consideró a los productores y acopiadores de cacao del municipio de Palermo ubicado en el departamento del Huila-Colombia. El presente, es un estudio aplicado, descriptivo y de tipo no experimental, cuya población de estudio son los productores y acopiadores de cacao del municipio. Para la realización del mismo, se desarrollaron entrevistas y se ejerció observación directa con el fin de determinar las actitudes estratégicas presentes en los procesos de negociación. Tras realizar una simulación computacional de las actitudes estratégicas de los involucrados por medio de un torneo de dilema del prisionero iterado, se concluyó que la formulación y ejecución de estrategias de cooperación, enmarcadas en la comunicación entre las partes, el mejoramiento de las relaciones y la reciprocidad generará un beneficio mutuo tanto para los campesinos productores como para los acopiadores de cacao