By using resin transfer molding (RTM) technology, carbon fiber (CF) reinforced epoxy composites (CF/Epoxy, CF/PES/Epoxy, and CF/PES-MWCNT/Epoxy) are prepared. CF is the reinforced fiber, Epoxy is the ...epoxy matrix, and PES-MWCNT is the multiwall carbon nanotubes doped polyethersulfone film. Their fire behavior is systematically studied according to limiting oxygen index (LOI), vertical burning test (UL94), and cone calorimeter test (CCT). Their thermal degradation process, kinetics, and flame retardant mechanism are investigated from thermogravimetric analysis (TGA) and scanning electronic microscopy (SEM). The results show that these composites can reach the highest UL94 rating with the 5VA level achieved. Moreover, introduction of PES-MWCNT improves the LOI values, reduces the total smoke production (TSP), and slightly decreases peak of heat release rate (PHRR) and total heat release (THR). This improvement in the flame retardancy results from the increased degradation activation energy (E a) and formation of stable protective char layers in the combustion process, as indicated by the thermodegradation kinetic analysis and the SEM observation of the char residues’ microstructure, respectively.
El presente artículo explora cómo los movimientos feministas en Montevideo han construido ciudad a través de la apropiación de espacios urbanos que promueven formas de habitar diversas. Se realiza un ...abordaje desde el concepto de derecho a la ciudad y la perspectiva del urbanismo feminista, que busca considerar las necesidades de grupos históricamente excluidos. Para ello, resulta fundamental reconocer que las ciudades han sido diseñadas desde una perspectiva masculina y analizar cómo los conflictos urbanos tienen su raíz en las violencias que experimentan las mujeres en su vida diaria y en la necesidad de resignificar y reclamar esos espacios. Se plantea un abordaje situado, atendiendo a las características de las nuevas formas de estar en el espacio público por parte de los feminismos latinoamericanos. A partir de la realización de un amplio análisis documental, entrevistas y observaciones sistemáticas, se profundiza en cómo el feminismo construye ciudad de diversas formas, tanto a nivel institucional como en la vida cotidiana. Resulta fundamental comprender los efectos que los movimientos feministas tienen en el ámbito urbano y la necesidad de identificar y abordar las conquistas, negociaciones, disputas y dificultades entre los diferentes actores involucrados. Así, e incorporando los aportes del urbanismo feminista, se aborda la capacidad de producción de estos conflictos, siguiendo la propuesta de Melé (2016), y se las categoriza en productividades de tipo políticas, jurídicas y territoriales. Se concluye que los efectos del movimiento feminista generan nuevas posibilidades para la construcción de una ciudad más justa.
Environmental agents such as pesticides, weedicides and herbicides (collectively referred to as pesticides) are associated with the onset and pathogenesis of neurodegenerative disorders such as ...Parkinson's (PD) and Alzheimer's (AD) diseases. The development of blood-brain barrier (BBB)-penetrating therapeutic candidates to both prevent and treat the aforementioned xenotoxicant-induced neurodegenerative disorders remains an unmet need. Here, we examine whether caffeic-acid based Carbon Quantum Dots (CACQDs) can intervene in pesticide-associated onset and progress of the PD phenotype. Pulse-chase fluorescence analyses revealed that CACQDs intervene in the soluble-to-toxic transformation of the amyloid-forming protein model Hen Egg White Lysozyme (HEWL). The sp2-rich CACQDs also scavenged free radicals, a milestone along the PD trajectory. In-vitro, CACQDs introduced into a human neuroblastoma-derived cell line (SH-SY5Y) demonstrated negligible cytotoxicity up to 5 mg/mL and protected the cell line against oxidative stress-induced neuronal injury induced by the pesticide and potent neurotoxin, paraquat. Our findings suggest that the potentially BBB-penetrating CACQDs derived from caffeic acid hold promise for mitigating neurodegenerative disorders associated with environmental pesticides and xenobiotic neurotoxicants. Importantly, CACQDs sourced from coffee, coupled with their facile synthesis, represent a sustainable, green chemistry platform for generating interventional candidates in neurodegeneration.
The application of caffeic acid derived Carbon Quantum Dots (CACQDs) to mitigate oxidative stress induced by paraquat. Display omitted
•Caffeic acid recarbonization offers a green chemistry approach to develop carbon nanomaterials.•BBB-penetrating caffeic acid quantum dots for prevention of neurodegeneration.•CACQDs as potent free radical scavengers for oxidative stress regulation.•CACQDs protect SH-SY5Y Cells against oxidative stress-induced neuronal injury by paraquat.
Hosts have evolved diverse strategies to respond to microbial infections, including the detection of pathogen-encoded proteases by inflammasome-forming sensors such as NLRP1 and CARD8. Here, we find ...that the 3CL protease (3CLpro) encoded by diverse coronaviruses, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), cleaves a rapidly evolving region of human CARD8 and activates a robust inflammasome response. CARD8 is required for cell death and the release of pro-inflammatory cytokines during SARS-CoV-2 infection. We further find that natural variation alters CARD8 sensing of 3CLpro, including 3CLpro-mediated antagonism rather than activation of megabat CARD8. Likewise, we find that a single nucleotide polymorphism (SNP) in humans reduces CARD8's ability to sense coronavirus 3CLpros and, instead, enables sensing of 3C proteases (3Cpro) from select picornaviruses. Our findings demonstrate that CARD8 is a broad sensor of viral protease activities and suggests that CARD8 diversity contributes to inter- and intraspecies variation in inflammasome-mediated viral sensing and immunopathology.
Carbon fiber-reinforced polymers, used in primary structures for aircraft due to an excellent strength-to-weight ratio when compared with conventional aluminium alloy counterparts, may nowadays be ...considered as mature structural materials. Their use has been extended in recent decades, with several aircraft manufacturers delivering fuselages entirely manufactured with carbon composites and using advanced processing technologies. However, one of the main drawbacks of using such composites entails their poor electrical conductivity when compared with aluminium alloy competitors that leads to lightning strikes being considered a significant threat during the service life of the aircraft. Traditionally, this problem was overcome with the use of a protective copper/bronze mesh that added additional weight and reduced the effectiveness of use of the material. Moreover, this traditional sizing method is based on vast experimental campaigns carried out by subjecting composite panels to simulated lightning strike events. While this method has proven its validity, and is necessary for certification of the structure, it may be optimized with the aid provided by physically based numerical models. This paper presents a model based on the finite element method that includes the sources of damage observed in a lightning strike, such as thermal damage caused by Joule overheating and electromagnetic/acoustic pressures induced by the arc around the attachment points. The results of the model are compared with lightning strike experiments carried out in a carbon woven composite.
Micro- and nano-plastics (NPs) are found in human milk, blood, tissues, and organs and associate with aberrant health outcomes including inflammation, genotoxicity, developmental disorders, onset of ...chronic diseases, and autoimmune disorders. Yet, interfacial interactions between plastics and biomolecular systems remain underexplored. Here, we have examined experimentally, in vitro, in vivo, and by computation, the impact of polystyrene (PS) NPs on a host of biomolecular systems and assemblies. Our results reveal that PS NPs essentially abolished the helix-content of the milk protein β-lactoglobulin (BLG) in a dose-dependent manner. Helix loss is corelated with the near stoichiometric formation of β-sheet elements in the protein. Structural alterations in BLG are also likely responsible for the nanoparticle-dependent attrition in binding affinity and weaker on-rate constant of retinol, its physiological ligand (compromising its nutritional role). PS NP-driven helix-to-sheet conversion was also observed in the amyloid-forming trajectory of hen egg-white lysozyme (accelerated fibril formation and reduced helical content in fibrils). Caenorhabditis elegans exposed to PS NPs exhibited a decrease in the fluorescence of green fluorescent protein-tagged dopaminergic neurons and locomotory deficits (akin to the neurotoxin paraquat exposure). Finally, in silico analyses revealed that the most favorable PS/BLG docking score and binding energies corresponded to a pose near the hydrophobic ligand binding pocket (calyx) of the protein where the NP fragment was found to make nonpolar contacts with side-chain residues via the hydrophobic effect and van der Waals forces, compromising side chain/retinol contacts. Binding energetics indicate that PS/BLG interactions destabilize the binding of retinol to the protein and can potentially displace retinol from the calyx region of BLG, thereby impairing its biological function. Collectively, the experimental and high-resolution in silico data provide new insights into the mechanism(s) by which PS NPs corrupt the bimolecular structure and function, induce amyloidosis and onset neuronal injury, and drive aberrant physiological and behavioral outcomes.
Neural angiostrongyliasis is an emerging zoonosis caused by the rat lungworm, Angiostrongylus cantonensis. In humans, infection with this nematode often results in eosinophilic meningitis and other ...severe disorders of the central nervous system. Europe was deemed a nonendemic region until 2018, when A. cantonensis worms were detected on the Mediterranean island of Mallorca, Spain, a tourism hotspot. Since that time, a sentinel surveillance system and a molecular approach have been used to follow the invasion path of the rat lungworm on the island. A. cantonensis worms have been found in animals from 8 locations on the island over 3 consecutive years. Our preliminary results show a recognizable pattern of clinical signs in infected hedgehogs and a single mitochondrial haplotype circulating in Mallorca. We present strong evidence confirming that the rat lungworm has successfully established and colonized an island in Europe and discuss observations and possible strategies for its early detection across continental Europe.
The aim of this work was to study the influence of a high efficient halogen-free phenylphosphonic amide flame retardant (FP1) to epoxy resin (brand name RTM6) on the rheological, mechanical and water ...absorption properties of the carbon fiber/RTM6 epoxy composite (CFR). With a 8 wt% loading FP1 in RMT6, the processing of CFR/FP1 was able to use the equal condition with that of CFR since the viscosity of RTM6 was maintained at a similar level in the minimum viscosity temperature region. The addition of FP1 showed negligible impacts on the interlayer share strength (ILSS) and in-plane share strength (IPSS) of CFR. The interfacial strength between RTM6 matrix and carbon fiber was decreased due to the impact of FP1 on cross-linking density and polarity of RTM6. The flame retardant efficiency of FP1 showed difference in presence of carbon fiber or not in RTM6. RTM6/FP1 (8 wt%) had a LOI value of 38%, achieved a V-0 rating at thickness of 3.2 mm in UL 94 test and showed 60% reduction in peak of heat release rate. RTM6/carbon fiber/FP1 (8 wt%) had a LOI of 43%, while it showed reduced performance in UL 94 and cone calorimeter tests.
Abstract
Background
Persistent headache attributed to past stroke (PHAPS) is a controversial entity, recently included in the third edition of the International Classification of Headache Disorders ...(ICHD-3) despite being described only in retrospective studies.
Objective
To determine the frequency and characteristics of PHAPS in patients admitted with acute stroke.
Methods
We selected all patients with headache associated with acute stroke (HAAS) from a prospective, single-center registry of patients with acute stroke admitted to a Neurology ward between November 2018 and December 2019. We analyzed demographic, clinical, and neuroimaging data. We assessed the follow-up with a phone call questionnaire at 6 to 12 months.
Results
Among 121 patients with acute stroke, only 29 (24.0%) had HAAS. From these, 6 (5.0%) were lost to follow-up. In total, 23 (20.0%) patients answered the 6- to 12-month follow-up questionnaire and were included in this study. The median age of the sample was 53 years (interquartile range IQR: 38–78 years), and there was no sex predominance. Of the 10 patients (8,3%) that had persistent headache, 8 (6.6%) suffered from previous chronic headaches; however, they all mentioned a different kind of headache, and 1 (0,8%) probably had headache secondary to medication.
Conclusions
In the present study, only 10 out of 121 stroke patients (8.3%) referred persistent headache at the 6- to 12-month follow-up, but the majority already suffered from previous chronic headache, which raises the question that the actual prevalence of PHAPS may be lower than previously reported.
Protein post-translational modifications (PTMs) are an important battleground in the evolutionary arms races that are waged between the host innate immune system and viruses. One such PTM, ...ADP-ribosylation, has recently emerged as an important mediator of host antiviral immunity. Important for the host-virus conflict over this PTM is the addition of ADP-ribose by PARP proteins and removal of ADP-ribose by macrodomain-containing proteins. Interestingly, several host proteins, known as macroPARPs, contain macrodomains as well as a PARP domain, and these proteins are both important for the host antiviral immune response and evolving under very strong positive (diversifying) evolutionary selection. In addition, several viruses, including alphaviruses and coronaviruses, encode one or more macrodomains. Despite the presence of the conserved macrodomain fold, the enzymatic activity of many of these proteins has not been characterized. Here, we perform evolutionary and functional analyses to characterize the activity of macroPARP and viral macrodomains. We trace the evolutionary history of macroPARPs in metazoans and show that PARP9 and PARP14 contain a single active macrodomain, whereas PARP15 contains none. Interestingly, we also reveal several independent losses of macrodomain enzymatic activity within mammalian PARP14, including in the bat, ungulate, and carnivore lineages. Similar to macroPARPs, coronaviruses contain up to three macrodomains, with only the first displaying catalytic activity. Intriguingly, we also reveal the recurrent loss of macrodomain activity within the alphavirus group of viruses, including enzymatic loss in insect-specific alphaviruses as well as independent enzymatic losses in two human-infecting viruses. Together, our evolutionary and functional data reveal an unexpected turnover in macrodomain activity in both host antiviral proteins and viral proteins.
