43 research outputs found
Novel hybrid organic/inorganic poly(thiourethane) covalent adaptable networks
Organic-inorganic hybrid materials combine the advantages of both phases: hardness and strength of inorganic phase and elasticity and toughness of the organic matrix. In the present study, we have prepared nanocomposites with a poly(thiourethane) polymeric matrix and silsesquioxane-type structures, with thiols as reactive groups (POSS-A or POSS-B, synthesized in different pressure conditions), looking for a covalent interaction between both phases, and good dispersion. Due to the click behavior of the reaction between the isocyanate and the thiol groups, highly homogeneous materials are obtained. Both monomers, catalyst (dibutyltin dilaurate, DBTDL), and the POSS precursor (3-mercaptopropyl trimethoxysilane, MPTMS), are commercially available, which present the advantage of being industrially scalable. The incorporation of POSS leads to an increase in glassy and rubbery storage moduli and the temperature of the maximum of tan delta curve. The vitrimeric behavior of the poly(thiourethanes) improved with the POSS incorporation, getting lower relaxation times. With a higher proportion of closed cages, POSS-B leads to the most significant improvements. All the materials prepared showed high transparency and the fracture of POSS modified materials indicates an improved toughness.This work is part of the R & D projects PID2020-115102RB-C21 and PID2020-115102RB-C22 funded by MCINAEI/10.13039/501100011033. We acknowledge these grants and the Generalitat de Catalunya (2017-SGR-77 and BASE3D) . The authors declare the following financial interests/personal re-lationships which may be considered as potential competing interests: Angels Serra reports financial support was provided by Spain Ministry of Science and Innovation
Disease-associated GRIN protein truncating variants trigger NMDA receptor loss-of-function
De novo GRIN variants, encoding for the ionotropic glutamate NMDA receptor subunits, have been recently associated with GRIN-related disorders, a group of rare paediatric encephalopathies. Current investigational and clinical efforts are focused to functionally stratify GRIN variants, towards precision therapies of this primary disturbance of glutamatergic transmission that affects neuronal function and brain. In the present study, we aimed to comprehensively delineate the functional outcomes and clinical phenotypes of GRIN protein truncating variants (PTVs)—accounting for ~20% of disease-associated GRIN variants—hypothetically provoking NMDAR hypofunctionality. To tackle this question, we created a comprehensive GRIN PTVs variants database compiling a cohort of nine individuals harbouring GRIN PTVs, together with previously identified variants, to build-up an extensive GRIN PTVs repertoire composed of 293 unique variants. Genotype–phenotype correlation studies were conducted, followed by cell-based assays of selected paradigmatic GRIN PTVs and their functional annotation. Genetic and clinical phenotypes meta-analysis revealed that heterozygous GRIN1, GRIN2C, GRIN2D, GRIN3A and GRIN3B PTVs are non-pathogenic. In contrast, heterozygous GRIN2A and GRIN2B PTVs are associated with specific neurological clinical phenotypes in a subunit- and domain-dependent manner. Mechanistically, cell-based assays showed that paradigmatic pathogenic GRIN2A and GRIN2B PTVs result on a decrease of NMDAR surface expression and NMDAR-mediated currents, ultimately leading to NMDAR functional haploinsufficiency. Overall, these findings contribute to delineate GRIN PTVs genotype–phenotype association and GRIN variants stratification. Functional studies showed that GRIN2A and GRIN2B pathogenic PTVs trigger NMDAR hypofunctionality, and thus accelerate therapeutic decisions for this neurodevelopmental condition.ISCIII, cofunded by European Regional Development Fund (ERDF), a way to build Europe (grants PI19/00348 and PI16/00851); Miguel Servet Program (CPII16/00021, ISCIII) and Serra Húnter Fellow to X.A.; SAF2016-77830-R to M.O.; European Regional development Fund (ERDF)-Ministerio de Ciencia e Innovación (grant BFU2017-83317-P) and Ministerio de Ciencia e Innovación-MarÃa de Maeztu (MDM-2017-0729) to D.S. and PI18/00111 [ISCIII, cofunded by European Regional Development Fund (ERDF), a way to build Europe] to À.G.-C. and N.J.-P.; Fundación Tatiana Pérez de Guzmán el Bueno PhD fellowship to A.S.-G.; crowdfunding initiative Precipita (FECYT) to F.M
Diagnosis of Genetic White Matter Disorders by Singleton Whole-Exome and Genome Sequencing Using Interactome-Driven Prioritization
Background and Objectives Genetic white matter disorders (GWMD) are of heterogeneous origin, with >100 causal genes identified to date. Classic targeted approaches achieve a molecular diagnosis in only half of all patients. We aimed to determine the clinical utility of singleton whole-exome sequencing and whole-genome sequencing (sWES-WGS) interpreted with a phenotype- and interactome-driven prioritization algorithm to diagnose GWMD while identifying novel phenotypes and candidate genes. Methods A case series of patients of all ages with undiagnosed GWMD despite extensive standard-of-care paraclinical studies were recruited between April 2017 and December 2019 in a collaborative study at the Bellvitge Biomedical Research Institute (IDIBELL) and neurology units of tertiary Spanish hospitals. We ran sWES and WGS and applied our interactome-prioritization algorithm based on the network expansion of a seed group of GWMD-related genes derived from the Human Phenotype Ontology terms of each patient. Results We evaluated 126 patients (101 children and 25 adults) with ages ranging from 1 month to 74 years. We obtained a first molecular diagnosis by singleton WES in 59% of cases, which increased to 68% after annual reanalysis, and reached 72% after WGS was performed in 16 of the remaining negative cases. We identified variants in 57 different genes among 91 diagnosed cases, with the most frequent being RNASEH2B, EIF2B5, POLR3A, and PLP1, and a dual diagnosis underlying complex phenotypes in 6 families, underscoring the importance of genomic analysis to solve these cases. We discovered 9 candidate genes causing novel diseases and propose additional putative novel candidate genes for yet-to-be discovered GWMD. Discussion Our strategy enables a high diagnostic yield and is a good alternative to trio WES/WGS for GWMD. It shortens the time to diagnosis compared to the classical targeted approach, thus optimizing appropriate management. Furthermore, the interactome-driven prioritization pipeline enables the discovery of novel disease-causing genes and phenotypes, and predicts novel putative candidate genes, shedding light on etiopathogenic mechanisms that are pivotal for myelin generation and maintenance
High prevalence of liver fibrosis among european adults with unknown liver disease: a population-based study
[Background & Aims] Liver fibrosis is the main determinant of long-term outcome in chronic liver diseases. Little is known about the prevalence of liver fibrosis in the general population. The aim of the study was to investigate the prevalence of liver fibrosis in the general adult population with unknown liver disease.[Methods] This was a population-based, cross-sectional study performed in the Barcelona metropolitan area. Subjects aged 18 to 75 years old were identified randomly from citizens included in the primary health care registry. Of 4866 subjects invited, 3076 participated (63.2%). Liver fibrosis was estimated by measuring liver stiffness (LS) with transient elastography (TE). Liver histology was assessed in 92 subjects with increased LS.[Results] Prevalence estimates of increased LS (≥6.8, ≥8.0, and ≥9.0 kPa) were 9.0%, 5.8%, and 3.6%, respectively. The etiology of liver disease was mainly nonalcoholic fatty liver disease (NAFLD), followed by alcohol risk consumption (consumption of ≥21 standard drinking units/wk in men and ≥14 standard drinking units/wk in women). Factors independently associated with increased LS were male sex, abdominal obesity, type 2 diabetes, serum glucose, high-density lipoprotein, and triglyceride levels. Subjects without risk factors for NAFLD or without alcohol risk consumption had a very low prevalence of increased LS. The best cut-off value of LS for significant liver fibrosis (F2–F4) was 9.2 kPa, with high sensitivity and specificity. TE was more accurate than alanine aminotransferase, NAFLD fibrosis score, or Fibrosis 4. An algorithm for screening for liver fibrosis using TE in the community setting is proposed.[Conclusions] These findings show a high prevalence of silent liver disease with advanced fibrosis mainly related to NAFLD in adult European subjects without known liver disease. An LS value less than 9.2 kPa predicts the absence of significant liver fibrosis with high accuracy and could be used for screening purposes.The project received a research grant from the Carlos III Institute of Health,
Ministry of Economy and Competitiveness (Spain), awarded on the 2011 call
under the Health Strategy Action 2013–2016, within the National Research
Program oriented to Societal Challenges, within the Technical, Scientific and
Innovation Research National Plan 2013–2016, with reference PI11/0267,
co-funded by European Union European Regional Development Fund funds.
Also supported by grants from Fondo de Investigación Sanitaria Instituto de
Salud Carlos III-Subdirección General de Evaluación and the European
Regional Development Fund Fondo Europeo de Desarrollo Regional (PI16/
00043), the Agencia de Gestió d’Ajuts Universitarisi de Recerca, and the
European Horizon 20/20 program, H20/20-SC1-2016-RTD, and an Institució
Catalana de Recerca I Estudis Avançats Academy Award (P.G.).Peer reviewe
Epoxy Sol-Gel Hybrid Thermosets
Sol-gel methodologies are advantageous in the preparation of hybrid materials in front of the conventional addition of nanoparticles, because of the fine dispersion of the inorganic phase that can be reached in epoxy matrices. In addition, the use of organoalkoxysilanes as coupling agents allows covalent linkage between organic and inorganic phases, which is the key point in the improvement of mechanical properties. The sol-gel process involves hydrolysis and condensation reactions under mild conditions, starting from hydrolysable metal alkoxides, generally alkoxy silanes. Using the sol-gel procedure, the viscosity of the formulation is maintained, which is an important issue in coating applications, whereas the transparency of the polymer matrix is also maintained. However, only the proper combination of the chemistries and functionalities of both organic and inorganic structures leads to thermosets with the desired characteristics. The adequate preparation of hybrid epoxy thermosets enables their improvement in characteristics such as mechanical properties (modulus, hardness, scratch resistance), thermal and flame resistance, corrosion and antimicrobial protection, and even optical performance among others
Epoxy-thiol thermosets modified by carbazole decorated hyperbranched poly(ethyleneimine) for optical applications
DOI: 10.1016/j.reactfunctpolym.2016.07.012
Link: http://www.sciencedirect.com/science/article/pii/S1381514816301432
Filiació URV: SINew epoxy-thiol thermosets containing carbazolyl moieties were prepared by adding different proportions of a hyperbranched poly(ethyleneimine) with carbazolyl terminated units to diglycidylether of bisphenol A/trimethylolpropane tris(3-mercaptopropionate) stoichiometric formulations. This carbazolyl decorated hyperbranched polymer was synthesized from commercially available hyperbranched poly(ethyleneimine) and N-glycidyl carbazole and was characterized by standard procedures.
The influence of adding different proportions of the modifier to the formulation on the curing process was determined by calorimetry after the selection of the most adequate latent initiator, which was a urethane compound, named PDU-250. Its decomposition at a well-defined temperature liberates the amine that initiates the thiol-epoxy curing process.
The materials obtained with different proportions of modifier were characterized by means of thermomechanical analysis. On increasing the proportion of modifier, the glass transition temperature and the damping characteristics increased, but the thermal stability and the homogeneity were reduced.
The films obtained by curing the different formulations exhibited fluorescence maxima at 370–374 nm. The fluorescence quantum yields were in the range of 17–32% and they decreased with the increase of the amount of the modifier in the materials
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Thermoconductive Thermosetting Composites Based on Boron Nitride Fillers and Thiol-Epoxy Matrices
In this work, the effect of the addition of boron nitride (BN) fillers in a thiol-cycloaliphatic epoxy formulation has been investigated. Calorimetric studies put into evidence that the kinetics of the curing has been scarcely affected and that the addition of particles does not affect the final structure of the network. Rheologic studies have shown the increase in the viscoelastic properties on adding the filler and allow the percolation threshold to be calculated, which was found to be 35.5%. The use of BN agglomerates of bigger size increases notably the viscosity of the formulation. Glass transition temperatures are not affected by the filler added, but Young’s modulus and hardness have been notably enhanced. Thermal conductivity of the composites prepared shows a linear increase with the proportion of BN particle sheets added, reaching a maximum of 0.97 W/K·m. The addition of 80 μm agglomerates, allowed to increase this value until 1.75 W/K·m