137 research outputs found

    Reservoir Cannulas for Pediatric Oxygen Therapy: A Proof-of-Concept Study

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    Hypoxemia is a complication of pneumonia—the leading infectious cause of death in children worldwide. Treatment generally requires oxygen-enriched air, but access in low-resource settings is expensive and unreliable. We explored use of reservoir cannulas (RCs), which yield oxygen savings in adults but have not been examined in children. Toddler, small child, and adolescent breathing profiles were simulated with artificial lung and airway models. An oxygen concentrator provided flow rates of 0 to 5 L/min via a standard nasal cannula (NC) or RC, and delivered oxygen fraction (FdO2) was measured. The oxygen savings ratio (SR) and absolute flow savings (AFS) were calculated, comparing NC and RC. We demonstrated proof-of-concept that pendant RCs could conserve oxygen during pediatric therapy. SR mean and standard deviation were 1.1±0.2 to 1.4±0.4, 1.1±0.1 to 1.7±0.3, and 1.3±0.1 to 2.4±0.3 for toddler, small child, and adolescent models, respectively. Maximum AFS observed were 0.3±0.3, 0.2±0.1, and 1.4±0.3 L/min for the same models. RCs have the potential to reduce oxygen consumption during treatment of hypoxemia in children; however, further evaluation of products is needed, followed by clinical analysis in patients

    Characterization of lignin and lignin-derivatives from biomass. Application as expander of lead-acid battery

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    Expanders, as lignosulfonates, are crucial for a good performance of Pb/acid batteries. In the process of discharge, the Pb and the PbO2 go to PbSO4. The formed PbSO4 is adsorbed on the surface of the Pb electrode and dramatically reduces the lifetime of the battery by the formation of big PbSO4 crystals. In order to prevent that, the addition of expanders in the negative electrode is an economic solution to prevent the formation of big crystals. In this investigation, we propose the synthesis of several lignosulfonates obtained from lignin of many biomass origins. We have derivatized nine samples of lignin via microwave-assisted sulfonation, then we have characterized how efficient is the chosen synthesis method. The lignosulfonates obtained have been characterized by infrared spectroscopy (IR), proton nuclear magnetic resonance (1HNMR), two-dimensional correlated spectroscopy (COSY), and elemental analysis to acquire some relevant information about their structure in terms of functional groups. In this way, three commercial lignosulfonates, Vanisperse A, Indulin AT, and Oakwood, have been selected as references for our comparisons. Moreover, we have checked their electrochemical properties, using electrochemical techniques to compare their behavior with respect to the commercial lignosulfonates. Finally, we have selected one of them and we have tested its performance as an expander in a Pb/acid battery. That result is a very promising first approach, and we can conclude that lignosulfonates derivatives are a good and low-cost choice to improve the lifetime of Pb/acid batteries. In particular, it is shown that the incorporation of LignosB improves the cell formation as well as the first capacity (36.30% more) and the charge acceptance (63.16% more), being these relevant parameters in the performance of Pb/acid batterie

    Precision and linearity targets for validation of an IFNγ ELISPOT, cytokine flow cytometry, and tetramer assay using CMV peptides

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    <p>Abstract</p> <p>Background</p> <p>Single-cell assays of immune function are increasingly used to monitor T cell responses in immunotherapy clinical trials. Standardization and validation of such assays are therefore important to interpretation of the clinical trial data. Here we assess the levels of intra-assay, inter-assay, and inter-operator precision, as well as linearity, of CD8+ T cell IFNγ-based ELISPOT and cytokine flow cytometry (CFC), as well as tetramer assays.</p> <p>Results</p> <p>Precision was measured in cryopreserved PBMC with a low, medium, or high response level to a CMV pp65 peptide or peptide mixture. Intra-assay precision was assessed using 6 replicates per assay; inter-assay precision was assessed by performing 8 assays on different days; and inter-operator precision was assessed using 3 different operators working on the same day. Percent CV values ranged from 4% to 133% depending upon the assay and response level. Linearity was measured by diluting PBMC from a high responder into PBMC from a non-responder, and yielded R<sup>2 </sup>values from 0.85 to 0.99 depending upon the assay and antigen.</p> <p>Conclusion</p> <p>These data provide target values for precision and linearity of single-cell assays for those wishing to validate these assays in their own laboratories. They also allow for comparison of the precision and linearity of ELISPOT, CFC, and tetramer across a range of response levels. There was a trend toward tetramer assays showing the highest precision, followed closely by CFC, and then ELISPOT; while all three assays had similar linearity. These findings are contingent upon the use of optimized protocols for each assay.</p

    Impact of cryopreservation on tetramer, cytokine flow cytometry, and ELISPOT

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    BACKGROUND: Cryopreservation of PBMC and/or overnight shipping of samples are required for many clinical trials, despite their potentially adverse effects upon immune monitoring assays such as MHC-peptide tetramer staining, cytokine flow cytometry (CFC), and ELISPOT. In this study, we compared the performance of these assays on leukapheresed PBMC shipped overnight in medium versus cryopreserved PBMC from matched donors. RESULTS: Using CMV pp65 peptide pool stimulation or pp65 HLA-A2 tetramer staining, there was significant correlation between shipped and cryopreserved samples for each assay (p ≤ 0.001). The differences in response magnitude between cryopreserved and shipped PBMC specimens were not significant for most antigens and assays. There was significant correlation between CFC and ELISPOT assay using pp65 peptide pool stimulation, in both shipped and cryopreserved samples (p ≤ 0.001). Strong correlation was observed between CFC (using HLA-A2-restricted pp65 peptide stimulation) and tetramer staining (p < 0.001). Roughly similar sensitivity and specificity were observed between the three assays and between shipped and cryopreserved samples for each assay. CONCLUSION: We conclude that all three assays show concordant results on shipped versus cryopreserved specimens, when using a peptide-based readout. The assays are also concordant with each other in pair wise comparisons using equivalent antigen systems

    Resource Recovery Potential From Lignocellulosic Feedstock Upon Lysis With Ionic Liquids

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    Lignocellulosic residues from energy crops offer a high potential to recover bioproducts and biofuels that can be used as raw matter for agriculture activities within a circular economy framework. Anaerobic digestion (AD) is a well-established driver to convert these residues into energy and bioproducts. However, AD of lignocellulosic matter is slow and yields low methane potential, and therefore several pre-treatment methods have been proposed to increase the energy yield of this process. Hereby, we have assessed the pre-treatment of lignocellulosic biomass (barley straw) with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate and its effect on the biochemical methane potential (BMP). The BMP of the residue was evaluated at different inoculum to substrate (I/S) ratios and working under meso and thermophilic conditions. Solids destruction upon AD is highly enhanced by the IL-pretreatment. This also resulted in a higher BMP, both in mesophilic as well as thermophilic conditions. At the optimum I/S ratio of 2:1 (dried weight, dw), the BMP of the IL-pre-treated feedstock increased 28 and 80% for 35 days of thermophilic and mesophilic AD, respectively, as compared to the fresh feedstock, achieving values of 364 and 412 LCH4/kgTS. We also explored the effect of this pretreatment on the phosphorus recovery potential from the digestate upon release from the AD process. Thermophilic anaerobic digestion of IL-pre-treated biomass provided the highest P recovery potential from lignocellulosic residues (close to 100% of the theoretical P content of the lignocellulosic feedstock). Therefore, the pretreatment of lignocellulosic feedstock with IL before AD is a promising platform to obtain bioenergy and recover P to be regained for the agriculture sector

    El pirocloro (H3O)NbWO6-nH2O como catalizador para la deshidratación de Fructosa a 5-hidroximetilfurfural (HMF)

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    5-hidroximetilfurfural (HMF) es una importante molécula plataforma en la síntesis de diversos productos químicos. En este trabajo, informamos la deshidratación de fructosa a HMF en un sistema bifásico que contiene H2O y MIBK-2-ButOH como fase orgánica y (H3O)NbWO6-nH2O con estructura pirocloro como catalizador. El pirocloro se preparó por química del estado sólido a partir del precursor KNbWO6, seguido de un intercambio iónico en ácido sulfúrico. Este sólido exhibió una alta acidez, demostrando ser activo como catalizador ácido en la deshidratación de fructosa a (HMF). El catalizador es muy estable, ya que no se observó lixiviación de especies de niobio y wolframio a la fase líquida. Los resultados mostraron que el catalizador tiene un efecto catalítico sinérgico positivo en la conversión de fructosa a HMF. El rendimiento más alto de HMF del 33 % se logró a 150 ° C durante 90 min.Fil: Mayer, Sergio Federico. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Falcon, Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Poncio, Carlos Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Ribotta, Pablo Daniel. Universidad Nacional de Córdoba. Secretaría de Ciencia y Tecnología. Instituto Superior de Investigación, Desarrollo y Servicio de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Perez, Susana. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Morales delaRosa, Silvia. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Campos Martín, José M.. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Alonso, José Antonio. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; EspañaFil: Fierro, José Luis G.. Instituto de Ciencia de Materiales de Madrid; EspañaXXI Congreso Argentino de Catálisis y X Congreso de Catálisis del MercosurSanta FeArgentinaSociedad Argentina de CatálisisInstituto de Investigaciones en Catálisis y PetroquímicaInstituto de Desarrollo Tecnológico para la Industria Químic

    NKG2D expression in CD4+ T lymphocytes as a marker of senescence in the aged immune system

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    Human aging is characterized by changes in the immune system which have a profound impact on the T-cell compartment. These changes are more frequently found in CD8+ T cells, and there are not well-defined markers of differentiation in the CD4+ subset. Typical features of cell immunosenescence are characteristics of pathologies in which the aberrant expression of NKG2D in CD4+ T cells has been described. To evaluate a possible age-related expression of NKG2D in CD4+ T cells, we compared their percentage in peripheral blood from 100 elderly and 50 young adults. The median percentage of CD4+ NKG2D+ in elders was 5.3% (interquartile range (IR): 8.74%) versus 1.4% (IR: 1.7%) in young subjects (p < 0.3 × 10−10). CD28 expression distinguished two subsets of CD4+ NKG2D+ cells with distinct functional properties and differentiation status. CD28+ cells showed an immature phenotype associated with high frequencies of CD45RA and CD31. However, most of the NKG2D+ cells belonged to the CD28null compartment and shared their phenotypical properties. NKG2D+ cells represented a more advanced stage of maturation and exhibited greater response to CMV (5.3 ± 3.1% versus 3.4 ± 2%, p = 0.037), higher production of IFN-γ (40.56 ± 13.7% versus 24 ± 8.8%, p = 0.015), lower activation threshold and reduced TREC content. Moreover, the frequency of the CD4+ NKG2D+ subset was clearly related to the status of the T cells. Higher frequencies of the NKG2D+ subset were accompanied with a gradual decrease of NAIVE and central memory cells, but also with a higher level of more differentiated subsets of CD4+ T cells. In conclusion, CD4+ NKG2D+ represent a subset of highly differentiated T cells which characterizes the senescence of the immune system
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