Caracterización de la madera de Castanea sativa Mill. de procedencia española

La madera de castaño de procedencia española no está presente como material estructural en la norma europea EN 1912, y por lo tanto no está asignada a ninguna clase resistente como sí lo están otras especies españolas. Por ello, en el presente trabajo se realizó una caracterización de madera aserrada de castaño de Asturias con fines estructurales, realizando los ensayos según la norma UNE EN 408:2004, y calculando sus valores característicos según la norma UNE EN 384:2010. Los valores obtenidos permitieron asignar una clase resistente de las establecidas en la norma UNE EN 338:2010. Fueron evaluadas un total de 260 probetas de dos secciones (40x100 y 40x150 mm) siendo asignada una clase resistente D24, resultando la densidad y la resistencia a flexión los parámetros limitantes y observándose un valor de módulo de elasticidad superior al correspondiente a dicha clase. La relación entre los módulo de elasticidad longitudinal y transversal obtenidos experimentalmente fue de 10 aproximadamente, mientras que la normativa establece, como valor genérico, 16. Se observó que la singularidad de la madera que provocó un mayor porcentaje de rotura fue la presencia de nudos, presentando estas probetas un valor de resistencia significativamente menor. Chestnut timber from Spain is not included as a structural timber in the European standard EN 1912 nor is it assigned to any strength class like other Spanish species. Therefore, a characterization of structural chestnut timber from Asturias was made according to the UNE EN 408:2004, and the characteristic values were calculated according to the UNE EN 384:2010. The values obtained allowed the assignment of a strength class according to UNE EN 338:2010. 260 samples of two sections (40x100 and 40x150 mm) were tested and a D24 strength class was assinged. Density and bending strength were the limiting parameters, and the value of modulus of elasticity was higher than the values asssigned to D24. The relationship between modulus of elasticity and the shear modulus obtained was approximately equal to 10, while this value in the UNE EN 384:2010 is set at 16. The characteristic of the wood which caused a higher percentage of failure was the presence of knots, resulting in significantly lower resistance values

Effects of Extracellular Matrix on the Morphology and Behaviour of Rabbit Auricular Chondrocytes in Culture

Isolated chondrocytes dedifferentiate to a fibroblast-like shape on plastic substrata and proliferate extensively, but rarely form nodules. However, when dissociation is not complete and some cartilage remnants are included in the culture, proliferation decreases and cells grow in a reticular pattern with numerous nodules, which occasionally form small cartilage-like fragments. In an attempt to reproduce this stable chondrogenic state, we added a cartilage protein extract, a sugar extract, and hyaluronan to the medium of previously dedifferentiated chondrocytes. When protein extract was added, many cartilaginous nodules appeared. Hyaluronan produced changes in cell phenotype and behaviour, but not nodule formation. Protein extract has positive effects on the differentiation of previously proliferated chondrocytes and permits nodule formation and the extensive production of type-II collagen. A comparison with incompletely dissociated chondrocyte cultures suggests that the presence of some living cells anchored to their natural extracellular matrix provides some important additional factors for the phenotypical stability of chondrocytes on plastic surfaces. In order to elucidate if it is possible that the incidence of apoptosis is related to the results, we also characterized the molecular traits of apoptosis

The physicochemical, biopharmaceutical, and in vitro efficacy properties of freeze-dried dexamethasone-loaded lipomers.

Dexamethasone-loaded polymer hybrid nanoparticles were developed as a potential tool to treat alopecia areata due to their follicular targeting ability. Freeze drying (FD) is a common technique used to improve nanoparticle stability; however, there are few studies focused on its effect on ethyl cellulose lipid-core nanoparticles. Nanoparticles were lyophilized with different cryoprotectants. Sucrose was selected because it allowed for a good resuspension and provided acceptable physicochemical parameters (374.33 nm, +34.7 mV, polydispersion 0.229%, and 98.87% encapsulation efficiency). The nanoparticles obtained were loaded into a pleasant xanthan gum hydrogel, and the rheological, release, and skin permeation profiles of different formulations were studied. The FD formulation significantly modified the particle size, and the drug release and permeation properties were also altered. In addition, analyses of the cytotoxicity and anti-inflammatory efficacy of FD and non-FD particles on human keratinocytes indicated no differences

An LRP6 mutation (Arg360His) associated with low bone mineral density but not cardiovascular events in a caucasian family

We present a family with a rare mutation of the LRP6 gene and for the first time provide evidence for its association with low bone mineral density. Introduction: The Wnt pathway plays a critical role in bone homeostasis. Pathogenic variants of the Wnt co-receptor LRP6 have been associated with abnormal skeletal phenotypes or increased risk of cardiovascular events. Patient and methods: Here we report an index premenopausal patient and her family carrying a rare missense LRP6 pathogenic variant (rs141212743; 0.0002 frequency among Europeans). This variant has been previously associated with metabolic syndrome and atherosclerosis, in the presence of normal bone mineral density. However, the LRP6 variant was associated with low bone mineral density in this family, without evidence for association with serum lipid levels or cardiovascular events. Conclusion: Thus, this novel association shows that LRP6 pathogenic variants may be involved in some cases of early-onset osteoporosis, but the predominant effect, either skeletal or cardiovascular, may vary depending on the genetic background or other acquired factors.Funding: Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Natur

Cocaine Effects on Dopaminergic Transmission Depend on a Balance between Sigma-1 and Sigma-2 Receptor Expression.

gma σ1 and σ2 receptors are targets of cocaine. Despite sharing a similar name, the two receptors are structurally unrelated and their physiological role is unknown. Cocaine increases the level of dopamine, a key neurotransmitter in CNS motor control and reward areas. While the drug also affects dopaminergic signaling by allosteric modulations exerted by σ1R interacting with dopamine D1 and D2 receptors, the potential regulation of dopaminergic transmission by σ2R is also unknown. We here demonstrate that σ2R may form heteroreceptor complexes with D1 but not with D2 receptors. Remarkably σ1, σ2, and D1 receptors may form heterotrimers with particular signaling properties. Determination of cAMP levels, MAP kinase activation and label-free assays demonstrate allosteric interactions within the trimer. Importantly, the presence of σ2R induces bias in signal transduction as σ2R ligands increase cAMP signaling whereas reduce MAP kinase activation. These effects, which are opposite to those exerted via σ1R, suggest that the D1 receptor-mediated signaling depends on the degree of trimer formation and the differential balance of sigma receptor and heteroreceptor expression in acute versus chronic cocaine consumption. Although the physiological role is unknown, the heteroreceptor complex formed by σ1, σ2, and D1 receptors arise as relevant to convey the cocaine actions on motor control and reward circuits and as a key factor in acquisition of the addictive habit. KEYWORDS: ERK1/2 phosphorylation; acute; addiction; cAMP; chronic; dopamine D1 and D2 receptors; label-free; signalin

Spherical means-based free-water volume fraction from diffusion MRI increases non-linearly with age in the white matter of the healthy human brain

Producción CientíficaThe term free-water volume fraction (FWVF) refers to the signal fraction that could be found as the cerebrospinal fluid of the brain, which has been demonstrated as a sensitive measure that correlates with cognitive performance and various neuropathological processes. It can be quantified by properly fitting the isotropic component of the magnetic resonance (MR) signal in diffusion-sensitized sequences. Using healthy subjects (178F/109M) aged 25-94, this study examines in detail the evolution of the FWVF obtained with the spherical means technique from multi-shell acquisitions in the human brain white matter across the adult lifespan, which has been previously reported to exhibit a positive trend when estimated from single-shell data using the bi-tensor signal representation. We found evidence of a noticeably non-linear gain after the sixth decade of life, with a region-specific variate and varying change rate of the spherical means-based multi-shell FWVF parameter with age, at the same time, a heteroskedastic pattern across the adult lifespan is suggested. On the other hand, the FW corrected diffusion tensor imaging (DTI) leads to a region-dependent flattened age-related evolution of the mean diffusivity (MD) and fractional anisotropy (FA), along with a considerable reduction in their variability, as compared to the studies conducted over the standard (single-component) DTI. This way, our study provides a new perspective on the trajectory-based assessment of the brain and explains the conceivable reason for the variations observed in FA and MD parameters across the lifespan with previous studies under the standard diffusion tensor imaging.Ministerio de Ciencia e Innovación (MCIN-AEI) y FEDER-UE (grant PID2021-124407NB-I00)Ministerio de Ciencia e Innovación (MCIN-AEI) - Unión Europea “NextGenerationEU/PRTR” (grant TED2021-130758B-I00)Ministry of Science and Higher Education (Poland) - Bekker programme (grant PPN/BEK/2019/1/00421)Norwegian ExtraFoundation for Health and Rehabilitation (2015/FO5146)European Union's Horizon 2020 research and Innovation program (ERC 802998

Minerales de Mn-Co-Ni en las lateritas De Cuba oriental: resultados preliminares

En los yacimientos de lateritas niquelíferas, el Ni y Co pueden ser incorporados en óxidos e hidróxido s de Mn, donde han precipitados mediante reacciones redox (Elias et al., 1981). Además de asbolanas (ricas en Ni y ricas en Co), otros minerales que contienen Co son heterogenita y litioforita (Chukhrov et al., 1 983; Manceau et al., 1987; Llorca y Monchoux, 1991)

A virtuous circle? The effects of university-industry relationships in a region with low absorptive capacity

This article examines the effects of university-industry relationships (UIRs) in a Spanish region - Valencian Community - with low absorptive capacity. The analysis considers two effects of UIRs, one on business innovation and the other on the scientific production of academic researchers. The results reveal that UIRs have no significant effects on either firms' technological innovation or academic scientific production. Therefore, these results suggest that, in territories with low absorptive capacity, UIRs, mainly R&D-based, do not produce the effects found in other contexts, which requires some rethinking about these types of territories. © 2020 The Author(s)

Infectiousness of patients with smear-negative pulmonary tuberculosis, assessed by Real-time Polymerase Chain Reaction, Xpert®MTB/RIF

Currently, pulmonary tuberculosis (TB) isolation recommendations are based on serial sputum smear microscopy. To assess infectiousness of smear-negative/GeneXpert-positive (Sm-/GXpert+) pulmonary TB, we evaluated 511 contacts of pulmonary TB patients attended at a teaching hospital in Spain (2010-2018). There were no statistically significant differences in rates of Mycobacterium tuberculosis infection (46.2% contacts of smear-positive and 34.6% contacts of Sm-/GXpert+ pulmonary TB patients, p=0.112). Sm-/GXpert+ pulmonary TB poses a substantial risk of transmission of M. tuberculosis infection. Our results add evidence to support including Real-time Polymerase Chain Reaction (Xpert®MTB/RIF) in the work-up diagnosis of suspected pulmonary TB cases to make decisions on air-borne isolation