Subject-specific one-dimensional fluid dynamics model of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) develops due to the accumulation of blood clots in the lung vasculature that obstructs flow and increases pressure. The mechanobiological factors that drive progression of CTEPH are not understood, in part because mechanical and hemodynamic changes in the small pulmonary arteries due to CTEPH are not easily measurable. Using previously published hemodynamic measurements and imaging from a large animal model of CTEPH, we applied a subject-specific one-dimensional (1D) computational fluid dynamic (CFD) approach to investigate the impact of CTEPH on pulmonary artery stiffening, time-averaged wall shear stress (TAWSS), and oscillatory shear index (OSI) in extralobar (main, right, and left) pulmonary arteries and intralobar (distal to the extralobar) arteries. Our results demonstrate that CTEPH increases pulmonary artery wall stiffness and decreases TAWSS in extralobar and intralobar arteries. Moreover, CTEPH increases the percentage of the intralobar arterial network with both low TAWSS and high OSI, quantified by the novel parameter φ , which is related to thrombogenicity. Our analysis reveals a strong positive correlation between increases in mean pulmonary artery pressure (mPAP) and φ from baseline to CTEPH in individual subjects, which supports the suggestion that increased φ drives disease severity. This subject-specific experimental-computational framework shows potential as a predictor of the impact of CTEPH on pulmonary arterial hemodynamics and pulmonary vascular mechanics. By leveraging advanced modeling techniques and calibrated model parameters, we predict spatial distributions of flow and pressure, from which we can compute potential physiomarkers of disease progression. Ultimately, this approach can lead to more spatially targeted interventions that address the needs of individual CTEPH patients

Removal of basic dyes from aqueous solutions by adsorption onto Moroccan clay (Fez city)

The main objective of this study was to investigate the potential of natural clay obtained (from Fez city, Morocco) as an adsorbent for the removal of basic dyes (Astrazon Blue BG and Astrazon Yellow 7GLL) from liquid effluents. Natural clay was characterised using different physical-chemical methods, including nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), pH of the point of zero charge (pHPZC) and Boehm titration method. The clay was tested to remove various textile dyes from the aqueous solution at room temperature. Parameters such as initial dye concentration, solution pH, adsorbent dosages and contact time were performed in a batch system for controlling the operating conditions. Experimental results data indicated that the adsorption process is a fast and spontaneous reaction. A pseudo-second-order kinetic model provides the best fit to the experimental data of BG and YL adsorption onto the natural clay. Theadsorption isotherm data of both the dyes onto the natural clay were fitted well to the Langmuir model. A maximum monolayer adsorption capacity of 101 mg.g-1 for BG and 127 mg.g-1 for YL are obtained at 298.15 K. The results suggest that the natural clay could be used as an inexpensive adsorbent for the removal of the textile dyes from aqueous solutions.Z. Bencheqroun isgrateful for her Erasmus grant. Authors are also Prof. Teresa Valente for help in the XRD analysis. This work has been developed under the scope of the projects: BioTecNorte (operation NORTE-01-0145-FEDER-000004), PTDC/AAGTEC/5269/2014and Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016).info:eu-repo/semantics/publishedVersio

Green synthesis of a novel clay-based catalyst supported magnetite and application as a tertiary treatment following chemical precipitation pretreatment of municipal wastewater of Fez city-Morocco

SSCI-VIDE+ATARI+MKC:LFI:AKD:JMC:CFEInternational audienceMunicipal wastewater of Fez city (Morocco) is considered one of contamination sources of the Sebou River in Morocco [1,2]. The present study deals with the fate of phenol as a compound of emergent concerns (CECs) supposed to be persistent after secondary treatment by the conventional processes in wastewater treatment plants (WWTP). Raw wastewater sampling upstream WWTP was performed periodically, followed by an exhaustive characterization. A primary treatment using coagulation-precipitation using ferric chloride was carried out to reduce the initial organic matter load and turbidity. Different treatment factors were optimized using response surface methodology (RSM). Thereafter, the pretreated and simulated wastewaters were spiked with phenol as probe compound, and its degradation was carried out in the heterogeneous Fenton process using synthesized magnetite-supported clay material by the co-precipitation method [3]. Results obtained from wastewater characterization confirm the moderate to high contamination strength of sampled wastewaters, and the preliminary treatment has reduced over 60 % of organics load. Matrix characterization of the pretreated wastewater before coupling to the Fenton process was detailed. On the other hand, the presence of magnetite phase and its high dispersion upon natural clay was confirmed by X-ray photoelectron microscopy (XPS), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM). Nitrogen adsorption-desorption and Brunauer-Emmett-Teller (BET) measurements showed an optimum clay to magnetite ratio of 2:1 (wt%). The application of heterogeneous Fenton for phenol degradation has been conducted upon simulated and pretreated wastewaters. Results showed almost total degradation of the initial phenol concentration of 50 mg.L-1 within 180 min at pH 3, and the catalyst was reused for several runs. Therefore, coagulation-precipitation coupled to heterogeneous Fenton may be a promising scheme for wastewater treatment

Removal of basic and acid dyes from aqueous solutions using cone powder from Moroccan cypress Cupressus sempervirens as a natural adsorbent

This study aims to evaluate the technical feasibility of applying a low-cost alternative natural bioadsorbent obtained from the cone of the Moroccan cypress Cupressus sempervirens to remove dyes from contaminated waters. Methylene Blue (MB) and Congo Red (CR) dyes are used to represent basic and acid compounds present in wastewater of textile industries. The cone of this medium-sized coniferous evergreen tree was obtained from the Fez area and was characterised by different physical-chemical methods, including nitrogen adsorption-desorption isotherms, Fourier transform infrared spectroscopy, scanning electron microscopy, Boehm titration method and the pH of the point of zero charge (pH(pzc)). Additionally, the influence of operating conditions such as contact time, initial dye concentration, binary mixture of dye solutions, bioadsorbent dosages and solution pH were evaluated. Experimental results reveal that the adsorption processes take place very rapidly, reaching equilibrium at 30 and 45 min for MB and CR, respectively. Maximum adsorption capacities result to be pH dependents. Hence, MB adsorption is favoured under basic pH conditions, while CR is favoured at acidic pH. A pseudo-second-order kinetic model provides the best fit of the experimental data of MB and CR adsorption onto the biomaterial. Adsorption isotherm data are well represented by Langmuir, Freundlich and Dubinin-Radushkevich models. Langmuir model gives the best fit with a maximum monolayer sorption capacity of 144 and 25.02 mg g(-1) for MB and CR, respectively. Experimental results indicate that the cone of Cupressus sempervirens could be used as a potential, low-cost bioadsorbent for the elimination of dyes from contaminated waters.The authors are grateful for the financial support provided by the Moroccan Environment Ministry (Project DE-LIX). They would also like to acknowledge the University of Minho for co-financing this research as part of the Erasmus mobility of PhD student Z. Bencheqroun (Erasmus Scholarship) by the projects BioTecNorte (operation NORTE-01-0145-FEDER-000004), PTDC/AAGTEC/5269/2014 and Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016)