5 research outputs found

    Influence of Carding and Pressing on Hygrothermal Properties and Fire Reaction of Hemp Fiber Nonwoven Mats

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    This article depicts the effect of carding and pressing on hygrothermal properties of hemp fibers nonwoven mats, trying to understand if their implementation can improve their behavior when employed as insulation materials in buildings. Hemp fibers belonging to Cannabis Sativa species and coming from local area (Apulia - Italy) were examined, then samples of carded and pressed hemp fibers nonwoven mats were prepared. According to European standards, the thermal conductivity, the vapor permeability and the fire reaction of hemp fibers samples were measured. Results were compared to each other and with those of a commercial nonwoven mat made with hemp (90 wt. %) and synthetic fibers (10 wt. %), used as reference. We observed that carded and pressed hemp fibers were characterized by a lower thermal conductivity when compared to unprocessed hemp fibers, likely because the removing of wood elements. On the other hand, not processed hemp fibers show higher breathability when compared to carded and pressed ones, as well as with respect to the commercial nonwoven mat. Moreover, it was proved that the absence of synthetic commingled fibers in hemp fibers allows a better behavior in fire reaction. At last, the improvement in terms of insulation properties of a hollow brick when filled with hemp fibers was verified, by comparing the thermal conductivities of an empty and a filled hollow brick; as expected, the filled hollow brick shows a lower thermal conductivity, underlining the effectiveness of hemp fibers as insulation material

    Pro-inflammatory monocyte profile in patients with major depressive disorder and suicide behaviour and how ketamine induces antiinflammatory M2 macrophages by NMDAR and mTOR

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    Background: Depression is a highly prevalent disorder that is one of the leading causes of disability worldwide. Despite an unknown aetiology, evidence suggests that the innate and adaptive immune systems play a significant role in the development and maintenance of major depressive disorder (MDD). The non-competitive glutamatergic N-methyl-D-aspartate receptor (NMDAR) antagonist, (R,S)-ketamine (ketamine), has demonstrated rapid and robust efficacy as an antidepressant when administered at sub-anaesthetic doses. Methods: Our goal was to characterize the pro-inflammatory profile of patients with MDD by measuring proinflammatory cytokines in plasma and circulating monocyte subsets and to understand how ketamine induces an anti-inflammatory program in monocyte and macrophages in vitro and vivo. Finding: Our results show that patients with MDD without other comorbidities (N= 33) exhibited significantly higher levels of pro-inflammatory IL-12 and IL-6 in plasma and that these cytokines were associated with increased numbers of non-classical (CD11b+ CD16brightCD14neg) monocytes and increased activation state (CD40+ CD86+ ) of classical monocytes in circulation. Remarkably, we have demonstrated that sub-anaesthetic doses of ketamine programs human monocytes into M2c-like macrophages by inducing high levels of CD163 and MERTK with intermediate levels of CD64 and stimulating mTOR-associated gene expression in vitro. The NMDAR antagonist MK-801, but not the a-amino-3‑hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) antagonist, NBQX, also polarizes macrophages to an M2c-like phenotype, but this phenotype disappears upon mTOR pathway inhibition. Subanaesthetic doses (10 mg/kg) of ketamine administration in mice both promote reduction of circulating classical pro-inflammatory monocytes and increase of alternative M2 macrophage subtypes in the spleen and CNS. Interpretation: Our results suggest an anti-inflammatory property of ketamine that can skew macrophages to an M2-like phenotype, highlighting potential therapeutic implications not only for patients with MDD but also other inflammatory-based diseases.Fil: Nowak, Wanda. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia.; ArgentinaFil: Grendas, Leandro Nicolás. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia.; ArgentinaFil: Sanmarco, Liliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Estecho, Ivana Gisele. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia.; ArgentinaFil: Arena, Ángeles Romina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia.; ArgentinaFil: Eberhardt, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Rodante, Demián Emanuel. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia.; ArgentinaFil: Aoki, María Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Daray, Federico Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia.; ArgentinaFil: Carrera Silva, Eugenio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Errasti, Andrea Emilse. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia.; Argentin

    Alkali-Activated Mortars for Sustainable Building Solutions: Effect of Binder Composition on Technical Performance

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    There is a growing interest in the construction sector in the use of sustainable binders as an alternative to ordinary Portland cement, the production of which is highly impacting on the environment, due to high carbon dioxide emissions and energy consumption. Alkali-activated binders, especially those resulting from low-cost industrial by-products, such as coal fly ash or metallurgical slag, represent a sustainable option for cement replacement, though their use is more challenging, due to some technological issues related to workability or curing conditions. This paper presents sustainable alkali-activated mortars cured in room conditions and based on metakaolin, fly ash, and furnace slag (both by-products resulting from local sources) and relevant blends, aiming at their real scale application in the building sector. The effect of binder composition—gradually adjusted taking into consideration technical and environmental aspects (use of industrial by-products in place of natural materials in the view of resources saving)—on the performance (workability, compressive strength) of different mortar formulations, is discussed in detail. Some guidelines for the design of cement-free binders are given, taking into consideration the effect of each investigated alumino-silicate component. The technical feasibility to produce the mortars with standard procedures and equipment, the curing in room conditions, the promising results achieved in terms of workability and mechanical performance (from 20.0 MPa up to 52.0 MPa), confirm the potential of such materials for practical applications (masonry mortars of class M20 and Md). The cement-free binders resulting from this study can be used as reference for the development of mortars and concrete formulations for sustainable building materials production
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