Defects of steroidogenesis

In the biosynthesis of steroid hormones the neutral lipid cholesterol, a normal constituent of lipid bilayers is transformed via a series of hydroxylation, oxidation, and reduction steps into a vast array of biologically active compounds: mineralocorticoids, glucocorticoids, and sex hormones. Glucocorticoids regulate many aspects of metabolism and immune function, whereas mineralocorticoids help maintain blood volume and control renal excretion of electrolytes. Sex hormones are essential for sex differentiation in male and support reproduction. They include androgens, estrogens, and progestins. A block in the pathway of steroid biosynthesis leads to the lack of hormones downstream and accumulation of the upstream compounds that can activate other members of the steroid receptor family. This review deals with the clinical consequences of these block

La producción de agua desalinizada en las regiones de Murcia y Valencia : balance de un recurso alternativo con luces y sombras

El litoral de las regiones de Murcia y Valencia ha sufrido grandes transformaciones territoriales durante las últimas décadas, debido a la fuerte expansión de las funciones residenciales, turísticas y de servicios. El Plan Hidrológico Nacional (2001) y, en mayor medida, el Programa A.G.U.A. (2004) apostaron por la desalinización de agua marina a gran escala para garantizar demandas urbanas, turísticas e incluso agrícolas. La paralización de los planes urbanísticos provocada por la crisis financiera (2007), unida a la tendencia de reducción del consumo de agua potable de la última década, evidencian una capacidad de producción de agua desalinizada muy superior a las necesidades del momento presente. Esta investigación revisa la situación actual de la desalinización de agua marina y salobre continental en las regiones de Murcia y Valencia, hace balance de sus ventajas e inconvenientes y plantea una discusión en torno al papel que puede desempeñar esta fuente no convencional como recurso estratégico y de futuro para garantizar demandas urbano-turísticas y agrícolas, principalmente durante situaciones de sequía.El litoral de les regions de Múrcia i València ha patit grans transformacions territorials durant les últimes dècades, a causa de la forta expansió de les funcions residencials, turístiques i de servicis. El Pla Hidrològic Nacional (2001) i, en major grau, el Programa A.G.U.A. (2004) van apostar per la dessalinització d'aigua marina a gran escala per a garantir demandes urbanes, turístiques i inclús agrícoles. La paralització dels plans urbanístics provocada per la crisi financera (2007), junt amb la tendència de reducció del consum d'aigua potable de l'última dècada, evidencien una capacitat de producció d'aigua dessalinitzada molt superior a les necessitats del moment present. Esta investigació revisa la situació actual de la dessalinització d'aigua marina i salobre continental en les regions de Múrcia i València, fa balanç dels avantatges i dels inconvenients que comporta i planteja una discussió entorn del paper que pot exercir esta font no convencional com a recurs estratégic i de futur per a garantir demandes urbano-turístiques i agrícoles, principalment durant situacions de sequera.The coast of the regions of Murcia and Valencia has undergone important land use changes in recent decades due to the intense expansion of tourism activity and residential and services uses. In general, the Spanish National Hydrological Plan of 2001, and especially the A.G.U.A. Program of 2004, supported large-scale water desalination to guarantee urban, tourism and rural water demand. The end of the urban sprawl due to the economic crisis, in addition to the decrease in drinking water consumption in the last decade, have resulted in a desalination water production capacity that is higher than current needs. This research reviews the current status of desalination water (from the sea and underground) in the regions of Murcia and Valencia. Moreover, it takes stock of its advantages and disadvantages, and discusses the role that this strategic and unconventional resource could play in the future to ensure urban, tourism and rural demands, especially during droughts.Les régions côtières de Murcia et de Valencia ont subi d'importantes transformations territoriales au cours des dernières décennies en raison de la forte expansion des fonctions résidentielles, touristiques et des services. Le Plan Hidrológico Nacional (2001) et notamment, le Programa A.G.U.A. (2004) ont parié sur le dessalement d'eau de mer à grande échelle pour répondre aux demandes urbaine, touristique et rurale. L'interruption des plans urbains provoquée par la crise financière (2007), s'ajoutant à une réduction de la consommation d'eau potable à partir de la dernière décennie mettent en évidence une capacité de production d'eau dessalée supérieure aux besoins actuels. Cette étude passe en revue l'état actuel du dessalement d'eau de mer et saumâtre dans les régions de Murcia et de Valencia. Il fait aussi un équilibre des avantages et des inconvénients et présente une discussion sur le rôle que cette source non conventionnelle stratégique et d'avenir peut jouer pour répondre aux demances urbaine, touristique et rurale, particulièrement en période de sécheresse

Matemáticas para la sociedad: una visión desde los libros de aritmética del siglo XVI

Dentro de las investigaciones en Historia de la Educación Matemática el análisis de libros antiguos utilizados para la enseñanza de las matemáticas supone una importante fuente de información. Esto se debe a que los textos antiguos ayudan a reconstruir los conceptos, a contextualizarlos y a conocer sus diversos acercamientos, a interrogarse sobre la validez de las formas de argumentar vigentes en otras épocas, y a buscar los fundamentos de las formas actuales. De la misma forma, aportan información sobre lo pedagógico: las formas de organizar y presentar el contenido, sus representaciones, las situaciones, problemas y ejercicios utilizados para explicar mejor los conceptos y métodos matemáticos (Gómez, 2001). En este sentido, el objetivo de este estudio es identificar el interés social que otorgan los autores de libros de aritmética del siglo XVI a las matemáticas, es decir, si los contenidos matemáticos presentes en las obras se pueden encontrar dentro de algún contexto cotidiano, científico, económico, militar, etc

New models for PIXE simulation with Geant4

Particle induced X-ray emission (PIXE) is a physical effect that is not yet adequately modelled in Geant4. The current status as in Geant4 9.2 release is reviewed and new developments are described. The capabilities of the software prototype are illustrated in application to the shielding of the X-ray detectors of the eROSITA telescope on the upcoming Spectrum-X-Gamma space mission.Comment: To be published in the Proceedings of the CHEP (Computing in High Energy Physics) 2009 conferenc

The Geant4-DNA project

The Geant4-DNA project proposes to develop an open-source simulation software based and fully included in the general-purpose Geant4 Monte Carlo simulation toolkit. The main objective of this software is to simulate biological damages induced by ionising radiation at the cellular and sub-cellular scale. This project was originally initiated by the European Space Agency for the prediction of deleterious effects of radiation that may affect astronauts during future long duration space exploration missions. In this paper, the Geant4-DNA collaboration presents an overview of the whole ongoing project, including its most recent developments already available in the last Geant4 public release (9.3 BETA), as well as an illustration example simulating the direct irradiation of a chromatin fibre. Expected extensions involving several research domains, such as particle physics, chemistry and cellular and molecular biology, within a fully interdiciplinary activity of the Geant4 collaboration are also discussed.Comment: presented by S. Incerti at the ASIA SIMULATION CONFERENCE 2009, October 7-9, 2009, Ritsumeikan University, Shiga, Japa

Update on the management of pediatric acute osteomyelitis and septic arthritis

Acute osteomyelitis and septic arthritis are two infections whose frequencies are increasing in pediatric patients. Acute osteomyelitis and septic arthritis need to be carefully assessed, diagnosed, and treated to avoid devastating sequelae. Traditionally, the treatment of acute osteoarticular infection in pediatrics was based on prolonged intravenous anti-infective therapy. However, results from clinical trials have suggested that in uncomplicated cases, a short course of a few days of parenteral antibiotics followed by oral therapy is safe and effective. The aim of this review is to provide clinicians an update on recent controversies and advances regarding the management of acute osteomyelitis and septic arthritis in children. In recent years, the emergence of bacterial species resistant to commonly used antibiotics that are particularly aggressive highlights the necessity for further research to optimize treatment approaches and to develop new molecules able to fight the war against acute osteoarticular infection in pediatric patients

Versatile and non-cytotoxic GelMA-xanthan gum biomaterial ink for extrusion-based 3D bioprinting

Extrusion-based 3D bioprinting allows the 3D printing of bioinks, composed of cells and biomaterials, to mimic the complex 3D hierarchical structure of native tissues. Successful 3D bioprinting requires bioinks with specific properties, such as biocompatibility, printability, and biodegradability according to the desired application. In the present work, we aimed at developing a new versatile blend of gelatin methacryloyl-xanthan gum (GelMA-XG) suitable for extrusion-based 3D bioprinting with a straightforward process. To this end, we first optimized the process of gelatin methacryloyl (GelMA) synthesis by investigating the impact of different buffer solutions on the degree of functionalization, swelling degree, and degradation rate. The addition of xanthan gum (XG) enabled further tuning of biodegradability and an improvement of GelMA printability. Specifically, an optimal concentration of XG was found through rheological characterization and printability tests. The optimized blend showed enhanced printability and improved shape fidelity as well as its degradation products turned out to be non-cytotoxic, thus laying the foundation for cell-based applications. In conclusion, our newly developed biomaterial ink is a promising candidate for extrusion-based 3D bioprinting