320 research outputs found
Electrodialysis with bipolar membranes for valorization of brines
Several industrial processes, such as desalination or neutralization, generate brines defined as concentrated solutions of salts in water, usually NaCl, typically discharged in the vicinities of the desalination plant or factory. To reduce the environmental impact and promote the valorization of the wasted resources, alternatives must be sought. Among sustainable alternatives for the recovery of brines, the possibility of using Electrodialysis with Bipolar Membranes (EDBM) is of interest, because it allows recovering brines as useful acids and bases. This review focuses on the discussion of the technical aspects of the EDBM as a means to treat streams rich in NaCl from reverse osmosis desalination and industrial processes in order to complete the direct delivery of chemicals for self-supply. The main environmental issues associated with desalination brine disposal are presented. The state-of-the-art of valorization of brines by EDBM to acids and bases is completed. This work concludes with an in-depth discussion of the technical, techno-economic and economic barriers that prevent the widespread use of EDBM technology.The authors gratefully acknowledge the funding for the projects CTQ2013-48280-C3-1-R-D and CTM2014-57833-R. Carolina Fernandez-Gonzalez also thanks the Spanish Ministry of Economy and Competitiveness for the FPI grant awarded BES-2012-053461
Valorization of desalination brines by electrodialysis with bipolar membranes using nanocomposite anion exchange membranes
Electrodialysis with bipolar membranes (EDBM) is a promising technology that simultaneously treats and valorizes desalination brines into acids and bases. An important techno-economic challenge of EDBM in this application is the purity of the products, related to the need for more selective ion exchange membranes with good stability working with acids and bases. This work presents the results of the treatment of model desalination brines by EDBM using nanocomposite anion exchange membranes in order to reduce the sulfate content as the main impurity in the acid stack. These membranes are composed by polyethylene, polypropylene, sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) (sPPO) and different loads of Fe2O3-SO42 − nanoparticles. A reduction of the sulfate content in the acid stack was observed when using nanocomposite membranes. The stability of these membranes was evaluated measuring the Cl−/SO42 − selectivity after 31 h, 62 h and 93 h of operation. FTIR spectra before and after 93 h of operation also confirmed the stability of the membranes. The evolution of the main impurities in the acid and the base stacks versus time when applying different current densities is included and related to current efficiency. An estimation of the proton and hydroxyl ions leakages at the different current densities is also presented.Financial support from MICINN under project 2014-57833-R and CTQ2013-48280-C3-1-R-D is gratefully acknowledged. The author thanks the Ministry of Education for FPI grant BES-2012-053461 and the scholarship EEBB-I-15-10268 for the stay at the Georgia Institute of Technology. In addition, this research was partially supported by the U.S. National Science Foundation CBET-1235166
Enhancing fouling resistance of polyethylene anion exchange membranes using carbon nanotubes and iron oxide nanoparticles
This work presents the enhancement of organic fouling resistance of nanocomposite anion exchange membranes made from a commercial polyethylene anion exchange membrane and a negative thin layer. This layer is composed of sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) (sPPO) and two nanomaterials of different geometry and composition, oxidized multi-walled carbon nanotubes CNTs-COO− (0.2% g g− 1 to 0.8% g g− 1) or sulfonated iron oxide nanoparticles Fe2O3-SO42 − (0.2% g g− 1 to 0.6% g g− 1). The novel nanocomposite membranes showed a relevant improvement in fouling resistance caused by the modification of some physicochemical characteristics of membrane surface such as charge, roughness and hydrophilicity. The nanocomposite layer did not show a change in the membrane resistance. No remarkable differences were detected when changing the nanomaterial during characterization of nanocomposite membranes. The optimized loading of iron oxide nanoparticles and carbon nanotubes at 0.4% and 0.6% improved membrane fouling resistance by 45% and 53%, respectively. The improved fouling resistance of the best nanocomposite membranes AM-0.6CNTs remained after 12 h of operation. Energy savings between 49% and 60% were also achieved.Financial support from MICINN under project CTM2014-57833-R and CTQ2013-48280-C3-1-R-D is gratefully acknowledged. The authors thank the Ministry of Education for the FPI grant BES-2012-053461 and the scholarship EEBB-I-15-10268. In addition, this research was partially supported by the U.S. National Science Foundation CBET-1235166
Electrochemical impedance spectroscopy of enhanced layered nanocomposite ion exchange membranes
This work presents the enhancement of Cl−/SO42− mono-selectivity of layered nanocomposite anion exchange membranes (AEMs) and the mechanism that supports this improvement. These nanocomposite membranes are based on commercial polyethylene AEMs and a nanocomposite negative thin layer composed of sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) and a functionalized nanomaterial, Fe2O3−SO42− nanoparticles or oxidized multi-walled carbon nanotubes CNTs-COO−. The mechanism for monovalent selectivity was confirmed by characterizing nanocomposite membranes and commercial heterogeneous ion exchange membranes (IEMs) using ζ-potential and electrochemical impedance spectroscopy (EIS). ζ-potential measurements confirmed the modification of the charge of surface of the membrane after being coated with the nanocomposite layer. EIS measurements showed a totally different electrical performance between layered nanocomposite membranes and commercial IEMs. The electrical data from EIS was fitted to a Maxwell-Wagner model providing an equivalent electric circuit (EEC) for each membrane. The observed differences in ECC were related to the structural differences of the membranes. A physical explanation of the phenomena that caused these differences is provided. The influence of ion concentration on EIS measurements was also studied. To the best of our knowledge, this is the first time that an ECC related to the structure of advanced layered IEMs is proposed.Financial support from MICINN under project CTM2014-57833-R and CTQ2013-48280-C3-1-R-D is gratefully acknowledged. The authors thank the Ministry of Economy, Industry and Competitiveness for the FPI grant BES-2012-053461 and the scholarships EEBB-I-15-10268 and EEBB-I-16-11614. In addition, this research was partially supported by the U.S. National Science Foundation CBET-1235166
Effect of Punicalagin and Ellagic Acid on Human Fibroblasts In Vitro: A Preliminary Evaluation of Their Therapeutic Potential
Background: Pomegranate is a fruit that contains various phenolic compounds, including punicalagin and ellagic acid, which have been attributed to anti-inflammatory, antioxidant, and anticarcinogenic properties, among others. Objective: To evaluate the effect of punicalagin and ellagic acid on the viability, migration, cell cycle, and antigenic profile of cultured human fibroblasts (CCD-1064Sk). MTT spectrophotometry was carried out to determine cell viability, cell culture inserts were used for migration trials, and flow cytometry was performed for antigenic profile and cell cycle analyses. Cells were treated with each phenolic compound for 24 h at doses of 10−5 to 10−9 M. Results: Cell viability was always significantly higher in treated versus control cells except for punicalagin at 10−9 M. Doses of punicalagin and ellagic acid in subsequent assays were 10−6 M or 10−7 M, which increased the cell migration capacity and upregulated fibronectin and α-actin expression without altering the cell cycle. Conclusions: These in vitro findings indicate that punicalagin and ellagic acid promote fibroblast functions that are involved in epithelial tissue healing.FEDER/Junta de Andalucía-Consejería de Universidad,
Investigación e Innovación/B-CTS-134-UGR20 Projec
Changes in moisture sources of atmospheric rivers landfalling the Iberian Peninsula with WRF-FLEXPART
This paper makes use of a combination of FLEXPART-WRF simulations forced with ERA5 and the CESM2 model—incorporated in the CMIP6 project—to infer a series of changes over the present century in the behavior of the landfalling atmospheric rivers (ARs) arriving to the Iberian Peninsula. In addition, future changes in the intensity and position of their main moisture sources are studied. In overall terms, there is a noticeable increase in the amount of moisture transported by ARs in the study region, particularly accentuated by the end of the century. However, no significant changes in the number of events are observed. A northward shift of both the mean position of the ARs as well as their main sources of moisture is also detected, particularly for the end of the century, and in the summer and fall months. In relation to the latter, an increase in the contribution of moisture contribution is also observed, quantitatively compatible with Clausius-Clapeyron amplification.Agencia Estatal de Investigación | Ref. PID2021-122314OB-I00Xunta de Galicia | Ref. ED481A‐2020/193Xunta de Galicia | Ref. ED431C 2021/44Universidade de Vigo/CISU
A deep intronic splice variant advises reexamination of presumably dominant SPG7 Cases
Objective: to identify causative mutations in a patient affected by ataxia and spastic paraplegia. Methods: whole-exome sequencing (WES) and whole-genome sequencing (WGS) were performed using patient's DNA sample. RT-PCR and cDNA Sanger sequencing were performed on RNA extracted from patient's fibroblasts, as well as western blot. Results: a novel missense variant in SPG7 (c.2195T> C; p.Leu732Pro) was first found by whole-exome sequencing (WES), while the second, also unreported, deep intronic variant (c.286 + 853A>G) was identified by whole-genome sequencing (WGS). RT-PCR confirmed the in silico predictions showing that this variant activated a cryptic splice site, inducing the inclusion of a pseudoexon into the mRNA sequence, which encoded a premature stop codon. Western blot showed decreased SPG7 levels in patient's fibroblasts. Interpretation: identification of a deep intronic variant in SPG7, which could only have been detected by performing WGS, led to a diagnosis in this HSP patient. This case challenges the notion of an autosomal dominant inheritance for SPG7, and illustrates the importance of performing WGS subsequently or alternatively to WES to find additional mutations, especially in patients carrying one variant in a gene causing a predominantly autosomal recessive disease
Heterogeneity in response to MCT and psychoeducation: a feasibility study using latent class mixed models in first-episode psychosis
Metacognitive training (MCT) is an effective treatment for psychosis. Longitudinal trajectories of treatment response are unknown but could point to strategies to maximize treatment efficacy during the first episodes. This work aims to explore the possible benefit of using latent class mixed models (LCMMs) to understand how treatment response differs between metacognitive training and psychoeducation. We conducted LCMMs in 28 patients that received MCT and 34 patients that received psychoeducation. We found that MCT is effective in improving cognitive insight in all patients but that these effects wane at follow-up. In contrast, psychoeducation does not improve cognitive insight, and may increase self-certainty in a group of patients. These results suggest that LCMMs are valuable tools that can aid in treatment prescription and in predicting response to specific treatments.Daniel Fernández has been supported by grant 2017 SGR 622 (GRBIO) administrated by the Departament d’Economia i Coneixement de la Generalitat de Catalunya (Spain) and by the Ministerio de Ciencia e Innovación (Spain) [PID2019-104830RB-I00/ DOI (AEI): 10.13039/501100011033]; and CIBER, Consorcio Centro de Investigación Biomédica en Red, Instituto de Salud Carlos III, Ministerio de Ciencia e InnovaciónPostprint (published version
Association between body composition and balance in older women
El objetivo de este estudio fue evaluar e identificar las relaciones existentes entre el Índice de Masa Corporal (IMC) y el porcentaje graso, con el equilibrio de mujeres mayores que viven en la Comunidad Autónoma de Extremadura, España. Se realizó un estudio transversal con una muestra de 188 mujeres extremeñas mayores de 55 años. Se evaluó el peso, la talla, el porcentaje graso mediante bioimpedancia y el equilibrio tanto dinámico como estático mediante estabilometría. Se realizó un análisis de regresión para evaluar las relaciones existentes entre estas variables, así como su valor predictivo. Los resultados nos informan de la asociación existente entre las variables porcentaje graso e IMC con el equilibrio dinámico, siendo esta última asociación la más significativa estadísticamente. Para concluir, se puede afirmar que existe una relación inversa entre los índices antropométricos IMC y porcentaje de grasa con el equilibrio dinámico.The aim of this study was to evaluate and identify the relationships between Body Mass Index (BMI) and fat percentage, with the balance of older women living in the Autonomous Community of Extremadura, Spain. A cross-sectional study was carried out with a sample of 188 women over 55 years of age in Extremadura. Weight, height, fat percentage by bioimpedance and both dynamic and static balance by stabilometry were assessed. A regression analysis was performed to evaluate the relationships between these variables, as well as their predictive value. The results show an association between the variables fat percentage and BMI and dynamic balance, the latter being the most statistically signifi cant. To conclude, it can be stated that there is an inverse relationship
between the anthropometric indices BMI and fat percentage and dynamic balance
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