Increasing Sorption Isotherms Accuracy: Weibull Modelling and Linear Regression

http://sherpa.ac.uk/romeo/search.php?issn=0144-5987Relying on an adequate mathematical approach, two different mathematical procedures can be applied to the huge database produced during gas sorption isotherm experiments in order to obtain accurate data to be used in the industrial practice. To treat data determined from gas sorption isotherms without a careful mathematical support will produce inaccurate results, because all the determinations will be dependent on human decision. The minimum error reported since the first stage of a sorption isotherm determination, which corresponds to volume calibrations of reference and sample cells performed through the use of helium, will produce enormous inaccuracies on sorption isotherm behavior. These inaccurate behaviors may sometimes invalidate any Coalbed Methane recovery and CO2 injection programs. The study consisted on investigating gas sorption isotherm accuracies determined during the first part of the sorption process, which is mainly conducted by monitoring the pressure decline with time, in the reference and the sample cells (when both cells are not in contact), until the stabilization stage is achieved. Three samples from two different coals were selected in order to study their gas sorption behavior, in terms of a clear mathematical approach, when submitted to three different gas compositions, viz. 99.999% methane (CH4); 99.999% carbon dioxide (CO2); and a gas mixture containing 74.99% CH4 + 19.99% CO2 + 5.02% nitrogen (N2). Sorption experiments allow to conclude that the three samples present the same mathematical response during the first part of the sorption process. However, all gas sorption data (adsorption and desorption) collected from reference cell have a better fitting to a Modified Weibull Model, and all gas sorption data (adsorption and desorption) collected from sample cell respond in a trustworthy way to a Linear Regression Model. Confidence bands and prediction intervals (or bands) were also computed.info:eu-repo/semantics/publishedVersio

Gas content derivative data versus diffusion coefficient

http://sherpa.ac.uk/romeo/issn/0144-5987/The study of the gas diffusion process has a main role in both Coalbed Methane (CBM) production and CO2 injection in geological sequestration projects. The accurate determination of gas diffusion coefficients in unconventional reservoirs such as coal seams, requires a consistent mathematical approach. The study of the gas diffusion process in coal seams was carried out using sorption isotherms. The Langmuir model for individual gases and the extended Langmuir model for multicomponent gas mixtures were applied to fit sorption isotherm data. “Gas content derivative data” and “gas content changes” emerged as crucial mathematical parameters to accurately study the gas diffusion process. The main goal of this paper is to define the degree of interaction between the gas content derivative data and the gas diffusion process. Experiments were performed on three samples selected from two different coals, which were submitted to three different gas compositions, viz 99.999% CH4; 99.999% CO2; and a gas mixture containing 74.99% CH4 + 19.99% CO2 + 5.02% N2, at 35ºC, and at pressures ranging from 0 up to 50 bar. Experimental results obtained from the three samples indicate that during adsorption/desorption processes, the diffusion coefficients increase and the gas content changes decrease when the pressure decreases, due to the sample saturation degrees and to the kinetic mechanisms increase. Additionally, the “gas content derivative data” scattering is slightly lower during the desorption process than during the adsorption process. These behaviors are clearly identified when using methane, but are even more evident when using CO2 and the gas mixture, due to the CO2 interaction with coal porous structure, which induces a considerable resistance to CO2 release. The results show that sample B (CH4 + CO2 + N2) displays higher diffusion coefficient values (this behaviour is mainly related to the presence of N2) than sample C (CH4) and than Sample A (CO2).info:eu-repo/semantics/publishedVersio

Co-culture fermentation of african native sorghum and millets whole grains - technological and biochemical potential of probiotic and indigenous strain combination

info:eu-repo/semantics/publishedVersio

Estudio de las propiedades de adsorción/desorción de gas en el carbón de la Cuenca de Sabinas en México: Study of gas adsorption/desorption properties in coals of Sabinas Basin on Mexico

http://sherpa.ac.uk/romeo/issn/2007-9753/El objetivo principal de esta investigación, se enfoca en el estudio de las propiedades de adsorción/desorción de CH4 en los yacimientos de gas asociado al carbón, los cuales se ubican en la porción noreste de México, con el fin de comprender su comportamiento desde el punto de vista de los yacimientos no convencionales. Para continuar con el desarrollo de este proyecto, se llevó a cabo una campaña de muestreo a cargo del Servicio Geológico Mexicano (SGM), el cual nos proporcionó 7 muestras de carbón bituminoso, procedentes de la Cuenca de Sabinas para su caracterización. La caracterización general incluyó: (1) Análisis inmediatos o primarios de humedad y ceniza, (2) Análisis elemental para la determinación de (C, H, O, N, y S), (3) Análisis petrográfico para determinar el tipo de materia orgánica, (4) Pirolisis Rock-Eval®6 para conocer su potencial petrolífero. El conjunto de estos análisis nos permitieron evaluar las muestras para desarrollar mediante “Isotermas de Langmuir” los ensayos de adsorción/desorción de CH4 y la interpretación de los parámetros que influyen en el proceso de adsorción. Para el desarrollo de las pruebas de adsorción/desorción se utilizó la técnica termo-volumétrica, observando capacidades de almacenamiento de gas metano de 202.11 scf/ton (7.07m3/ton) a 364.76 scf/ton (10.47m3/ton). Estos resultados nos permitieron interpretar las características físicas y químicas que influyen en la capacidad de almacenamiento del gas en el carbón. Anticipando como conclusión general que: la adsorción del gas aumenta con el rango/madurez. También se estudió la influencia de la composición maceral en el proceso de sorción y se verificó que la capacidad de almacenamiento de gas está íntimamente relacionada al contenido de vitrinita. Esto nos condujo a retomar las declaraciones de algunos autores (Chalmers y Bustin, 2008; Zhang et al, 2012) quienes verificaron que la capacidad de adsorción en base al COT aumenta en el siguiente orden: tipo I < tipo II < tipo III. Esto se atribuyó a que la vitrinita tiene una mayor capacidad de adsorción, en comparación con otros tipos de macerales.The main objective of this research was to study the gas adsorption/desorption properties in Coal Bed Methane reservoirs located in the North-eastern Mexico, and to understand the behavior of unconventional reservoirs. The Servicio Geológico Mexicano (SGM) performed a sampling campaign. For the characterization, the SGM providing us 7 bituminous coal samples from the Sabinas Basin. The general characterization included: (1) immediate or primary moisture and ash analysis (2) elemental analysis for (C, H, O, N, and S) quantification, (3) petrographic analysis for organic matter type determination, (4) Rock-Eval®6 Pyrolysis, for oil potential generation determination. After results evaluation, 7 samples were selected, in order to develop adsorption/desorption CH4 tests by “Langmuir Isotherms” and to understand of parameters affecting the adsorption process. Using thermo-volumetric technique could be observed storage capacities of methane gas between 202.11 scf/ton (7.07m3/ton) and 364.76 scf/ton (10.47 m3/ton). The adsorption/desorption tests results, let us to identify the physical and chemical characteristics of the samples influencing the gas storage capacity in the coal. A general conclusion is given; the gas adsorption increases with the rank/maturity. Also, the influence of the maceral composition in the process of sorption is recognized, and the capacity of gas storage is closely related to the vitrinite content. According to Chalmers y Bustin (2008), and Zhang et al. (2012), the capacity of adsorption as TOC, increases in the next order: type I < type II < type III. This is attributed to high adsorption capacity of vitrinite, compared with other macerals types.info:eu-repo/semantics/publishedVersio

Biochemical characterization and cytotoxic effect of the skin secretion from the red-spotted Argentina frog Argenteohyla siemersi (Anura: Hylidae)

Background: Argenteohyla siemersi (red-spotted Argentina frog) is a casque-headed tree frog species belonging to the Hylidae family. This species has a complex combination of anti-predator defense mechanisms that include a highly lethal skin secretion. However, biochemical composition and biological effects of this secretion have not yet been studied. Methods: The A. siemersi skin secretion samples were analyzed by mass spectrometry and chromatographic analysis (MALDI-TOF/MS, RP-HPLC and GC-MS). Proteins were also studied by SDS-PAGE. Among the biological activities evaluated, several enzymatic activities (hemolytic, phospholipase A2 , clotting, proteolytic and amidolytic) were assessed. Furthermore, the cytotoxic activity (cytolysis and fluorescence staining) was evaluated on myoblasts of the C2C12 cell line. Results: The MALDI-TOF/MS analysis identified polypeptides and proteins in the aqueous solution of A. siemersi skin secretion. SDS-PAGE revealed the presence of proteins with molecular masses from 15 to 55 kDa. Steroids, but no alkaloids or peptides (less than 5 kDa), were detected using mass spectrometry. Skin secretion revealed the presence of lipids in methanolic extract, as analyzed by CG-MS. This secretion showed hemolytic and phospholipase A2 activities, but was devoid of amidolytic, proteolytic or clotting activities. Moreover, dose-dependent cytotoxicity in cultured C2C12 myoblasts of the skin secretion was demonstrated. Morphological analysis, quantification of lactate dehydrogenase release and fluorescence staining indicated that the cell death triggered by this secretion involved necrosis. Conclusions: Results presented herein evidence the biochemical composition and biological effects of A. siemersi skin secretion and contribute to the knowledge on the defense mechanisms of casque-headed frogs.Fil: Fusco, Luciano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Cajade, Rodrigo. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de Biología. Laboratorio de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piñeiro, Jose Miguel. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de Biología. Laboratorio de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Torres, Ana M.. Universidad Nacional del Nordeste; ArgentinaFil: da Silva, Igor R. F.. Universidade Estadual de Campinas; BrasilFil: Hyslop, Stephen. Universidade Estadual de Campinas; BrasilFil: Leiva, Laura Cristina Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Pimenta, Daniel C.. Governo do Estado de Sao Paulo. Secretaria da Saude. Instituto Butantan; BrasilFil: Bustillo, Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin

NRF2 function in osteocytes is required for bone homeostasis and drives osteocytic gene expression

Osteocytes, the most abundant bone cell type, are derived from osteoblasts through a process in which they are embedded in an osteoid. We previously showed that nutrient restriction promotes the osteocyte transcriptional program and is associated with increased mitochondrial biogenesis. Here, we show that increased mitochondrial biogenesis increase reactive oxygen species (ROS) levels and consequently, NRF2 activity during osteocytogenesis. NRF2 activity promotes osteocyte-specific expression of Dmp1, Mepe, and Sost in IDG-SW3 cells, primary osteocytes, and osteoblasts, and in murine models with Nfe2l2 deficiency in osteocytes or osteoblasts. Moreover, ablation of Nfe2l2 in osteocytes or osteoblasts generates osteopenia and increases osteoclast numbers with marked sexual dimorphism. Finally, treatment with dimethyl fumarate prevented the deleterious effects of ovariectomy in trabecular bone masses of mice and restored osteocytic gene expression. Altogether, we uncovered the role of NRF2 activity in osteocytes during the regulation of osteocyte gene expression and maintenance of bone homeostasis

Glucose Restriction Promotes Osteocyte Specification by Activating a PGC-1α-Dependent Transcriptional Program

Osteocytes, the most abundant of bone cells, differentiate while they remain buried within the bone matrix. This encasement limits their access to nutrients and likely affects their differentiation, a process that remains poorly defined. Here, we show that restriction in glucose supply promotes the osteocyte transcriptional program while also being associated with increased mitochondrial DNA levels. Glucose deprivation triggered the activation of the AMPK/PGC-1 pathway. AMPK and SIRT1 activators or PGC-1α overexpression are sufficient to enhance osteocyte gene expression in IDG-SW3 cells, murine primary osteoblasts, osteocytes, and organotypic/ ex vivo bone cultures. Conversely, osteoblasts and osteocytes deficient in Ppargc1a and b were refractory to the effects of glucose restriction. Finally, conditional ablation of both genes in osteoblasts and osteocytes generate osteopenia and reduce osteocytic gene expression in mice. Altogether, we uncovered a role for PGC-1 in the regulation of osteocyte gene expression. Molecular Mechanism of Behavior; Molecular Physiology; Specialized Functions of Cell

Glucose Restriction Promotes Osteocyte Specification by Activating a PGC-1α-Dependent Transcriptional Program.

Osteocytes, the most abundant of bone cells, differentiate while they remain buried within the bonematrix. This encasement limits their access to nutrients and likely affects their differentiation, a pro-cess that remains poorly defined. Here, we show that restriction in glucose supply promotes the oste-ocyte transcriptional program while also being associated with increased mitochondrial DNA levels.Glucose deprivation triggered the activation of the AMPK/PGC-1 pathway. AMPK and SIRT1 activa-tors or PGC-1aoverexpression are sufficient to enhance osteocyte gene expression in IDG-SW3 cells,murine primary osteoblasts, osteocytes, and organotypic/ex vivobone cultures. Conversely, osteo-blasts and osteocytes deficient inPpargc1aandbwere refractory to the effects of glucose restriction.Finally, conditional ablation of both genes in osteoblasts and osteocytes generate osteopenia andreduce osteocytic gene expression in mice. Altogether, we uncovered a role for PGC-1 in the regula-tion of osteocyte gene expression

GO-DACT : a phase 3b randomised, double-blind, placebo-controlled trial of GOlimumab plus methotrexate (MTX) versus placebo plus MTX in improving DACTylitis in MTX-naive patients with psoriatic arthritis

© author(s) (or their employer(s)) 2020. Re-use permitted under CC BY- nC. no commercial re-use. see rights and permissions. Published by BMJ. This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-­NC 4.0) license.Objectives: To assess the efficacy of golimumab in combination with methotrexate (MTX) versus MTX monotherapy in psoriatic arthritis (PsA) dactylitis. Methods: Multicentre, investigator-initiated, randomised, double-blind, placebo-controlled, parallel-design phase 3b trial in 11 Portuguese rheumatology centres. Patients with PsA along with active dactylitis and naive to MTX and biologic disease-modifying antirheumatic drugs (bDMARDs) were randomly assigned to golimumab or placebo, both in combination with MTX. The primary endpoint was Dactylitis Severity Score (DSS) change from baseline to week 24. Key secondary endpoints included DSS and Leeds Dactylitis Index (LDI) response, and changes from baseline in the LDI and MRI dactylitis score. Analysis was by intention-to-treat for the primary endpoint. Results: Twenty-one patients received golimumab plus MTX and 23 MTX monotherapy for 24 weeks. One patient from each arm discontinued. Patient inclusion was halted at 50% planned recruitment due to a favourable interim analysis. Median baseline DSS was 6 in both arms. By week 24, patients treated with golimumab plus MTX exhibited significantly greater improvements in DSS relative to MTX monotherapy (median change of 5 vs 2 points, respectively; p=0.026). In the golimumab plus MTX arm, significantly higher proportions of patients achieved at least 50% or 70% improvement in DSS and 20%, 50% or 70% improvement in LDI in comparison to MTX monotherapy. Conclusions: The combination of golimumab and MTX as first-line bDMARD therapy is superior to MTX monotherapy for the treatment of PsA dactylitis.info:eu-repo/semantics/publishedVersio

The GO-DACT protocol : a multicentre, randomized, double-blind, parallel-group study to compare the efficacy of golimumab in combination with methotrexate (MTX) versus MTX monotherapy

© 2001-2020 Sociedade Portuguesa de ReumatologiaThe GO-DACT is an investigator-initiated, national, multicentric randomized placebo-controlled double-blinded trial, that assesses dactylitis as primary endpoint. Psoriatic arthritis patients naïve to methotrexate and biologic disease modifying anti-rheumatic drugs, with at least one active dactylitis, were assigned to golimumab in combination with methotrexate or placebo in combination with methotrexate, for 24 weeks. Both clinical (dactylitis severity score and the Leeds dactylitis index) and imaging (high resolution magnetic resonance imaging), among others, were assessed as outcomes. The main objective of GO-DACT is to provide evidence to improve the treatment algorithm and care of psoriatic arthritis patients with active dactylitis. In this manuscript we describe the GO-DACT protocol and general concepts of the methodology of this trial.info:eu-repo/semantics/publishedVersio