On the Analysis of the Contact Conditions in Temporomandibular Joint Prostheses

Temporomandibular joint replacement (TMJR) is a complex surgical procedure in which the artificial joints available must assure the anatomical reconstruction and guarantee a good range of the natural temporomandibular joint (TMJ) movements. With this aim, different types of TMJ prostheses, including the stock prosthetic system and custom-made prostheses, are being currently implanted. Although temporomandibular joint replacements (TMJRs) are expected to accomplish their function during a number of years, they might actually fail and need to be replaced. This paper analyzes different design factors affecting the contact stress distributions within the TMJ prosthesis interface, which are consequently involved in their deterioration and final failure of the prosthetic device. With this purpose, a numerical model based on finite elements has been carried out in order to evaluate the stress states attained in different prosthesis configurations corresponding to general types of TMJ prostheses. On the other hand, the actual degradation of resected implants has been evaluated via optical microscopy. The linkage between the numerical simulations performed and experimental evidence allowed the authors to establish the different wear and damage mechanisms involved in the failure of stock TMJ prostheses. Indeed, the results obtained show that the contact stresses at the interface between the mandible and the glenoid fossa components play a key role in the failure process of the TMJR devices

The government is following the science: why is the translation of evidence into policy generating so much controversy?

In the UK, the government has presented itself as guided by scientific evidence in its policy responses to COVID-19. This has led to science, in particular epidemiology, itself becoming politicised and contested. However, neither the politicisation of science nor questions surrounding the status of evidence are new. In this post, Luis Pérez-González, outlines how a similar politics of expertise has played out in environmental policy-making. The author argues that for scientific evidence to be successfully communicated in policy, it needs to be informed by bipartisan values

Hypoxic Cell Waves around Necrotic Cores in Glioblastoma: A Biomathematical Model and its Therapeutic Implications

Glioblastoma is a rapidly evolving high-grade astrocytoma that is distinguished pathologically from lower grade gliomas by the presence of necrosis and microvascular hiperplasia. Necrotic areas are typically surrounded by hypercellular regions known as "pseudopalisades" originated by local tumor vessel occlusions that induce collective cellular migration events. This leads to the formation of waves of tumor cells actively migrating away from central hypoxia. We present a mathematical model that incorporates the interplay among two tumor cell phenotypes, a necrotic core and the oxygen distribution. Our simulations reveal the formation of a traveling wave of tumor cells that reproduces the observed histologic patterns of pseudopalisades. Additional simulations of the model equations show that preventing the collapse of tumor microvessels leads to slower glioma invasion, a fact that might be exploited for therapeutic purposes.Comment: 29 pages, 9 figure

Chloroplast damage induced by the inhibition of fatty acid synthesis triggers autophagy in chlamydomonas

Fatty acids are synthesized in the stroma of plant and algal chloroplasts by the fatty acid synthase complex. Newly synthesized fatty acids are then used to generate plastidial lipids that are essential for chloroplast structure and function. Here, we show that inhibition of fatty acid synthesis in the model alga Chlamydomonas reinhardtii activates autophagy, a highly conserved catabolic process by which cells degrade intracellular material under adverse conditions to maintain cell homeostasis. Treatment of Chlamydomonas cells with cerulenin, a specific fatty acid synthase inhibitor, stimulated lipidation of the autophagosome protein ATG8 and enhanced autophagic flux. We found that inhibition of fatty acid synthesis decreased monogalactosyldiacylglycerol abundance, increased lutein content, down-regulated photosynthesis, and increased the production of reactive oxygen species. Electron microscopy revealed a high degree of thylakoid membrane stacking in cerulenin-treated cells. Moreover, global transcriptomic analysis of these cells showed an up-regulation of genes encoding chloroplast proteins involved in protein folding and oxidative stress and the induction of major catabolic processes, including autophagy and proteasome pathways. Thus, our results uncovered a link between lipid metabolism, chloroplast integrity, and autophagy through a mechanism that involves the activation of a chloroplast quality control system.Ministerio de Economía y Competitividad BFU2015-68216-PJunta de Andalucía CVI-7336, BIO2015-74432-JI

Autophagy is activated and involved in cell death with participation of cathepsins during stress-induced microspore embryogenesis in barley

Microspores are reprogrammed towards embryogenesis by stress. Many microspores die after this stress, limiting the efficiency of microspore embryogenesis. Autophagy is a degradation pathway that plays critical roles in stress response and cell death. In animals, cathepsins have an integral role in autophagy by degrading autophagic material; less is known in plants. Plant cathepsins are papain-like C1A cysteine proteases involved in many physiological processes, including programmed cell death. We have analysed the involvement of autophagy in cell death, in relation to cathepsin activation, during stress-induced microspore embryogenesis in Hordeum vulgare. After stress, reactive oxygen species (ROS) and cell death increased and autophagy was activated, including HvATG5 and HvATG6 up-regulation and increase of ATG5, ATG8, and autophagosomes. Concomitantly, cathepsin L/F-, B-, and H-like activities were induced, cathepsin-like genes HvPap-1 and HvPap-6 were up-regulated, and HvPap-1, HvPap-6, and HvPap-19 proteins increased and localized in the cytoplasm, resembling autophagy structures. Inhibitors of autophagy and cysteine proteases reduced cell death and promoted embryogenesis. The findings reveal a role for autophagy in stress-induced cell death during microspore embryogenesis, and the participation of cathepsins. Similar patterns of activation, expression, and localization suggest a possible connection between cathepsins and autophagy. The results open up new possibilities to enhance microspore embryogenesis efficiency with autophagy and/or cysteine protease modulators.España, MINECO AGL2014-52028-R and AGL2017-82447-

La solidaridad de las obligaciones mercantiles en el Anteproyecto de Código Mercantil

El Código de comercio español vigente no recoge prescripción general sobre el régimen de responsabilidad de las obligaciones con varios deudores, por lo que debe acudirse al Código civil que establece, de forma terminante, un régimen de presunción de mancomunidad para las mismas, si bien sí hay numerosas disposiciones legales en sentido contrario. Tanto la doctrina científica (civil y mercantil) como la Jurisprudencia, han reclamado, para estas obligaciones, en el ámbito mercantil, el carácter solidario de la deuda. El Anteproyecto de Código mercantil supone un gran avance en esta materia pues no sólo incluye numerosas normas que recogen el principio de la responsabilidad solidaria, sino que en un precepto consagra de modo general, la solidaridad de las obligaciones mercantiles, lo que puede entenderse ya como una característica distintiva y diferenciadora de las obligaciones civiles

IPSC differentiation into ependymal progenitors to treat ventricular damage during hydrocephalus

Introduction: During both obstructive congenital hydrocephalus and post-hemorrhagic hydrocephalus additional pathological events are intimately associated with their ethiology: a) a detrimental inflammatory response; b) severe damage of the underlying periventricular nervous tissue, including white matter, and c). Therapeutic approaches have been directed to overcome a) and b), however recovery of damaged neuroepithelium/ependyma is, in our present, an important therapeutic gap. Methods: Human and mouse induced pluripotent stem cells (iPSC) have been artificially differented into ependymal progenitors. Intracerebroventricular (ICV) injections of iPCS are performed ex vivo and in vivo in the damaged ventricular wall. Their integration and differentiation has been studied by immunohistochemistry and histopathological analysis. Results: Mice and human ependymal progenitors are able to integrate and differentiate into ependyma in damaged ventricular wall. Stage of ependymal differentiation by the time of the injection defined different degrees of integration. Conclusions: IPSC appear to be a good ependymal progenitor source with no ethical controversy associated.RyC 2014-16980 Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Strain mapping and nanocrystallite size determination by neutron diffraction in an aluminum alloy (AA5083) severely plastically deformed through equal channel angular pressing

Six specimens of an aluminum alloy (AA-5083) extruded by Equal Channel Angular Pressing following two different routes plus a blank sample were examined with a neutron radiation of 1.5448 Å. Macrostrain maps from the (311) reflection were obtained. A clear difference about accumulated macrostrain with the extrusion cycles between the two routes is shown. The diffraction data of annealed specimens did permit to estimate crystallite sizes that range between 89 nm and 115 nm depending on the routes

Estrategias de aprendizaje, género y rendimiento académico

[Resumen] Este trabajo estudia qué estrategias de aprendizaje son eficaces para obtener un buen rendimiento académico. Se utilizó el ACRA y las notas finales de curso en una muestra de 254 estudiantes desde 20 de la E.S.O. a 10 de Bachillerato. Se estudiaron las diferencias entre los grupos por rendimiento académico, género y curso. El alumnado que alcanza un buen rendimiento académico utiliza con más éxito que el de mal rendimiento, algunas tácticas propias del proceso de adquisición de la información, codificación, recuperación y apoyo al procesamiento de la información. Las chicas utilizan más las estrategias metacognitivas y están más motivadas intrínseca y extrínsecamente que los chicos.[Abstract] This work studies which 1eaming strategies are effective to get good academic results. We have used the ACRA and the final marks in a samp1e of 254 students from 20 of E.S.O. to 10 of Bachillerato. We have studied the differences among the groups according to heir academic results, sexes and school years. The students who get good academic results are able to use, more successfully than those with worse results,some strategies characteristic of the process of information coding, retaking and support to information processing. Metacognitive strateies are more used by gir1s, and these are more motivated, intrinscally nd extrinsically, than boy