20 research outputs found

    Vitrimeric Epoxy-Amine Polyimine Networks Based on a Renewable Vanillin Derivative

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    A series of bio-based polyimine vitrimers was obtained and characterized. A diimine-diglycidyl monomer (DIDG) was synthesized by condensing vanillin with 4,4'-oxydianiline (ODA) and further glycidylation with epichlorohydrin. This compound was cross-linked with three different Jeffamines (Jeff230, JeffD400, and JeffT403) with a different number of poly(propylene glycol) units in their structure and different functionalities. Trimethylolpropane triglycidyl ether (TMPTE) was added to the formulation to improve the thermal, mechanical, and thermomechanical properties. All of the materials prepared showed Tg’s above 66 °C, good vitrimeric behavior being the maximum relaxation rate reached by the material prepared from JeffD400, which also allows the most extensive degradation when treated with an acidic aqueous solution. These polyimine vitrimers can entirely relax the stress in less than 10.5 min at 150 °C without any added catalyst. All of the materials prepared could be satisfactorily recycled up to 200 °C also presenting an excellent self-welding ability.Peer ReviewedPostprint (published version

    Edge effects and vertical stratification of aerial insectivorous bats across the interface of primary-secondary Amazonian rainforest

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    Research ArticleEdge effects, abiotic and biotic changes associated with habitat boundaries, are key drivers of community change in fragmented landscapes. Their influence is heavily modulated by matrix composition. With over half of the world’s tropical forests predicted to become forest edge by the end of the century, it is paramount that conservationists gain a better understanding of how tropical biota is impacted by edge gradients. Bats comprise a large fraction of tropical mammalian fauna and are demonstrably sensitive to habitat modification. Yet, knowledge about how bat assemblages are affected by edge effects remains scarce. Capitalizing on a whole-ecosystem manipulation in the Central Amazon, the aims of this study were to i) assess the consequences of edge effects for twelve aerial insectivorous bat species across the interface of primary and secondary forest, and ii) investigate if the activity levels of these species differed between the understory and canopy and if they were modulated by distance from the edge. Acoustic surveys were conducted along four 2-km transects, each traversing equal parts of primary and ca. 30-year-old secondary forest. Five models were used to assess the changes in the relative activity of forest specialists (three species), flexible forest foragers (three species), and edge foragers (six species). Modelling results revealed limited evidence of edge effects, except for forest specialists in the understory. No significant differences in activity were found between the secondary or primary forest but almost all species exhibited pronounced vertical stratification. Previously defined bat guilds appear to hold here as our study highlights that forest bats are more edge-sensitive than edge foraging bats. The absence of pronounced edge effects and the comparable activity levels between primary and old secondary forests indicates that old secondary forest can help ameliorate the consequences of fragmentation on tropical aerial insectivorous batsinfo:eu-repo/semantics/publishedVersio

    High cut-off membrane for in- vivo dialysis of free plasma hemoglobin in a patient with massive hemolysis

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    Background: The possibility of clearing Cell-free Plasma Hemoglobin (CPH) from human plasma may appear attractive, especially when considering the noxious effects that CPH has on the immune function and the renal damage caused by its filtration. The existence of the so-called High Cut-Off (HCO) filters, possessing pores as big as 60 kDa, could potentially allow the clearance of the αβ dimers (31.3 kDa), the form in which the α2β2 hemoglobin tetramers (62.6 kDa) physiologically dissociate in plasma. We present herein the first reported case in which such an attempt was made. Case presentation: The patient was a 51-year-old man with hemolytic crisis due to glucose-6-phosphate dehydrogenase deficiency, further complicated by pigment-induced nephropathy. He underwent a 48-h CVVHD session, in which a HCO filter was used. The Sieving Coefficient (SC) for CPH was initially 0.08 and decreased to 0.02 after 24 h. This unexpected low SC was due to the initial high concentration of CPH (4.24 g/L). At such concentrations, the α2β2 tetramer poorly dissociates into the αβ dimer; but increases exponentially at concentrations lower than 1 g/L. Conclusions: Clearance of CPH through a HCO filter is technically feasible but its performance markedly relies on the initial concentration of CPH. Critically ill patients with smoldering hemolysis, as it happens during septic shock or ECMO treatment, may benefit the most from the use of this membrane in order to clear CPH

    Experiencia del IBV en programas europeos (2007-2013)

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    Blanco Bahamonde, M.; Sorolla Ballesta, C.; Adriá Sánchez, JV.; Ferris Oñate, JM.; Garcia Molina, C.; Gomez Pellin, A.; López López, J.... (2013). Experiencia del IBV en programas europeos (2007-2013). Revista de biomecánica. 60:61-63. http://hdl.handle.net/10251/49704S61636

    Decapping Protein Edc4 Regulates Dna Repair And Phenocopies Brca1

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    BRCA1 is a tumor suppressor that regulates DNA repair by homologous recombination. Germline mutations in BRCA1 are associated with increased risk of breast and ovarian cancer and BRCA1 deficient tumors are exquisitely sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. Therefore, uncovering additional components of this DNA repair pathway is of extreme importance for further understanding cancer development and therapeutic vulnerabilities. Here, we identify EDC4, a known component of processing-bodies and regulator of mRNA decapping, as a member of the BRCA1-BRIP1-TOPBP1 complex. EDC4 plays a key role in homologous recombination by stimulating end resection at double-strand breaks. EDC4 deficiency leads to genome instability and hypersensitivity to DNA interstrand cross-linking drugs and PARP inhibitors. Lack-of-function mutations in EDC4 were detected in BRCA1/2-mutation-negative breast cancer cases, suggesting a role in breast cancer susceptibility. Collectively, this study recognizes EDC4 with a dual role in decapping and DNA repair whose inactivation phenocopies BRCA1 deficiency

    Clinical and Pathological Characterization of Lynch-Like Syndrome

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    Background & aims: Lynch syndrome is characterized by DNA mismatch repair (MMR) deficiency. Some patients with suspected Lynch syndrome have DNA MMR deficiencies but no detectable mutations in genes that encode MMR proteins-this is called Lynch-like syndrome (LLS). There is no consensus on management of patients with LLS. We collected data from a large series of patients with LLS to identify clinical and pathology features. Methods: We collected data from a nationwide-registry of patients with colorectal cancer (CRC) in Spain. We identified patients whose colorectal tumors had loss of MSH2, MSH6, PMS2, or MLH1 (based on immunohistochemistry), without the mutation encoding V600E in BRAF (detected by real-time PCR), and/or no methylation at MLH1 (determined by methylation-specific multiplex ligation-dependent probe amplification), and no pathogenic mutations in MMR genes, BRAF, or EPCAM (determined by DNA sequencing). These patients were considered to have LLS. We collected data on demographic, clinical, and pathology features and family history of neoplasms. The χ2 test was used to analyze the association between qualitative variables, followed by the Fisher exact test and the Student t test or the Mann-Whitney test for quantitative variables. Results: We identified 160 patients with LLS; their mean age at diagnosis of CRC was 55 years and 66 patients were female (41%). The Amsterdam I and II criteria for Lynch syndrome were fulfilled by 11% of cases and the revised Bethesda guideline criteria by 65% of cases. Of the patients with LLS, 24% were identified in universal screening. There were no proportional differences in sex, indication for colonoscopy, immunohistochemistry, pathology findings, or personal history of CRC or other Lynch syndrome-related tumors between patients who met the Amsterdam and/or Bethesda criteria for Lynch syndrome and patients identified in universal screening for Lynch syndrome, without a family history of CRC. Conclusions: Patients with LLS have homogeneous clinical, demographic, and pathology characteristics, regardless of family history of CRC

    Co-occurrence of mutations in NF1 and other susceptibility genes in pheochromocytoma and paraganglioma

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    IntroductionThe percentage of patients diagnosed with pheochromocytoma and paraganglioma (altogether PPGL) carrying known germline mutations in one of the over fifteen susceptibility genes identified to date has dramatically increased during the last two decades, accounting for up to 35-40% of PPGL patients. Moreover, the application of NGS to the diagnosis of PPGL detects unexpected co-occurrences of pathogenic allelic variants in different susceptibility genes.MethodsHerein we uncover several cases with dual mutations in NF1 and other PPGL genes by targeted sequencing. We studied the molecular characteristics of the tumours with co-occurrent mutations, using omic tools to gain insight into the role of these events in tumour development.ResultsAmongst 23 patients carrying germline NF1 mutations, targeted sequencing revealed additional pathogenic germline variants in DLST (n=1) and MDH2 (n=2), and two somatic mutations in H3-3A and PRKAR1A. Three additional patients, with somatic mutations in NF1 were found carrying germline pathogenic mutations in SDHB or DLST, and a somatic truncating mutation in ATRX. Two of the cases with dual germline mutations showed multiple pheochromocytomas or extra-adrenal paragangliomas - an extremely rare clinical finding in NF1 patients. Transcriptional and methylation profiling and metabolite assessment showed an “intermediate signature” to suggest that both variants had a pathological role in tumour development.DiscussionIn conclusion, mutations affecting genes involved in different pathways (pseudohypoxic and receptor tyrosine kinase signalling) co-occurring in the same patient could provide a selective advantage for the development of PPGL, and explain the variable expressivity and incomplete penetrance observed in some patients

    Rheological behavior of honey of orange blossom at high deformation rates

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    Se procede a efectuar un estudio, desde el punto de vista reologico, de la miel de azahar, estudiando las modificaciones que, sobre este comportamiento, infieren las variaciones térmicas.A rheologicai study was conducted on honev of orange blossom, investigating the variations undergone by this rheological model due te environmental influence.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Dual-cured thermosets based on eugenol derivatives and thiol chemistry

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    This paper aims to increase sustainability in thermosetting polymeric fields using bio-based monomers and environmentally friendly processing technologies based on dual-curing. Eugenol has been transformed into acrylate epoxy eugenol (AEEU) that can participate in thio-Michael additions and thiol-epoxy reactions. These reactions constitute the first and second steps of the sequential dual-curing process. A basic catalyst has been added to favor the kinetics of the curing process. We have selected three thiols with functionalities 3, 4, and 6, the first is derived from eugenol, and the others are derived from pentaerythritol, all can be obtained from renewable resources. To tailor and improve the intermediate material characteristics in the dual-curing process, we have added the triacrylate of glycerol. By changing its proportion, a liquid or a rubbery solid can be obtained as an intermediate, which allows a significant number of application technologies. Rheology, DSC, and FTIR were used to follow the evolution of both curing steps and to confirm the sequential character of the dual-curing. The thermal characteristics of intermediate and final materials have been evaluated by TGA and DMTA. Tensile tests at break were performed to evaluate the mechanical properties.This work is part of the R&D projects PID2020-115102RB-C21 and PID2020-115102RB-C22 funded by MCNI/AEI/10.13039/501100011033 and European Union “NextGenerationEU”/PRTR. We acknowledge these grants, and we also thank the Generalitat de Catalunya (2021-SGR00154). Bruno Bock Thiochemicals is acknowledge for kindly giving us thiol monomers.Postprint (author's final draft
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