668 research outputs found

    Influences of Combined Organic Fouling and Inorganic Scaling on Flux and Fouling Behaviors in Forward Osmosis

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    This study investigated the influence of combined organic fouling and inorganic scaling on the flux and fouling behaviors of thin-film composite (TFC) forward osmosis (FO) membranes. Two organic macromolecules, namely, bovine serum albumin (BSA) and sodium alginate (SA), and gypsum (GS), as an inorganic scaling agent, were selected as model foulants. It was found that GS scaling alone caused the most severe flux decline. When a mixture of organic and inorganic foulants was employed, the flux decline was retarded, compared with when the filtration was performed with only the inorganic scaling agent (GS). The early onset of the conditioning layer formation, which was due to the organics, was probably the underlying mechanism for this inhibitory phenomenon, which had suppressed the deposition and growth of the GS crystals. Although the combined fouling resulted in less flux decline, compared with GS scaling alone, the concoction of SA and GS resulted in more fouling and flux decline, compared with the mixture of BSA and GS. This was because of the carboxyl acidity of the alginate, which attracted calcium ions and formed an intermolecular bridge

    Membrane and Electrochemical Processes for Water Desalination: A Short Perspective and the Role of Nanotechnology

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    In the past few decades, membrane-based processes have become mainstream in water desalination because of their relatively high water flux, salt rejection, and reasonable operating cost over thermal-based desalination processes. The energy consumption of the membrane process has been continuously lowered (from >10 kWh m(-3) to similar to 3 kWh m(-3)) over the past decades but remains higher than the theoretical minimum value (similar to 0.8 kWh m(-3)) for seawater desalination. Thus, the high energy consumption of membrane processes has led to the development of alternative processes, such as the electrochemical, that use relatively less energy. Decades of research have revealed that the low energy consumption of the electrochemical process is closely coupled with a relatively low extent of desalination. Recent studies indicate that electrochemical process must overcome efficiency rather than energy consumption hurdles. This short perspective aims to provide platforms to compare the energy efficiency of the representative membrane and electrochemical processes based on the working principle of each process. Future water desalination methods and the potential role of nanotechnology as an efficient tool to overcome current limitations are also discussed

    Improvements of motion vector in variational echo tracking technique by correction of initial guess

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    Póster presentado en: 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019

    Evaluation of the pathogenicity of GJB3 and GJB6 variants associated with nonsyndromic hearing loss

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    AbstractA number of genes responsible for hearing loss are related to ion recycling and homeostasis in the inner ear. Connexins (Cx26 encoded by GJB2, Cx31 encoded by GJB3 and Cx30 encoded by GJB6) are core components of gap junctions in the inner ear. Gap junctions are intercellular communication channels and important factors that are associated with hearing loss. To date, a molecular genetics study of GJB3 and GJB6 as a causative gene for hearing loss has not been performed in Korea. This study was therefore performed to elucidate the genetic characteristics of Korean patients with nonsyndromic sensorineural hearing loss and to determine the pathological mechanism of hearing loss by analyzing the intercellular communication function of Cx30 and Cx31 variants. Sequencing analysis of the GJB3 and GJB6 genes in our population revealed a total of nine variants, including four novel variants in the two genes. Three of the novel variants (Cx31-p.V27M, Cx31-p.V43M and Cx-30-p.I248V) and two previously reported variants (Cx31-p.V84I and Cx30-p.A40V) were selected for functional studies using a pathogenicity prediction program and assessed for whether the mutations were located in a conserved region of the protein. The results of biochemical and ionic coupling tests showed that both the Cx31-p.V27M and Cx31-p.V84I variants did not function normally when each was expressed as a heterozygote with the wild-type Cx31. This study demonstrated that two variants of Cx31 were pathogenic mutations with deleterious effect. This information will be valuable in understanding the pathogenic role of GJB3 and GJB6 mutations associated with hearing loss

    Curcumin induces expression of 15-hydroxyprostaglandin dehydrogenase in gastric mucosal cells and mouse stomach in vivo: AP-1 as a potential target

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    15-Hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the conversion of oncogenic prostaglandin E-2 to non-tumerigenic 15-keto prostaglandin E-2. In the present study, we found that curcumin, a yellow coloring agent present in the rhizome of Curcuma Tonga Linn (Zingiberaceae), induced expression of 15-PGDH at the both transcriptional and translational levels in normal rat gastric mucosal cells. By using deletion constructs of 15-PGDH promoter, we were able to demonstrate that activator protein-1 (AP-1) is the principal transcription factor responsible for regulating curcumin-induced 15-PGDH expression. Curcumin enhanced the expression of c-jun and cFos that are functional subunits of AP-1, in the nuclear fraction of cells. Silencing of c-jun suppressed curcumin-induced expression of 15-PGDH. Moreover, the chromatin immunoprecipitation assay revealed curcumin-induced binding of c-Jun to the AP-1 consensus sequence present in the 15-PGDH promoter. Curaimin increased phosphorylation of ERK1/2 and JNK. and pharmacologic inhibition of these kinases abrogated the curcumin-induced phosphorylation of clun and 15-PGDH expression. In contrast, tetrahydrocurcumin which lacks the alpha,beta-unsaturated carbonyl group failed to induce 15-PGDH expression, suggesting that the electrophilic carbonyl group of curcumin is essential for its induction of 15-PGDH expression. Curcumin restored the expression of 15-PGDH which is down-regulated by Helicobater pylori through suppression of DNA methyltransferase 1. In addition, oral administration of curcumin increased the expression of 15-PGDH and its regulators such as p-ERK1/2, p-JNK and c-Jun in the mouse stomach. Taken together, these findings suggest that curcumin-induced upregulation of 15-PGDH may contribute to chemopreventive effects of this phytochemical on inflammation-associated gastric carcinogenesis. (C) 2020 Elsevier Inc. All rights reserved.

    Growth differentiation factor 11 locally controls anterior-posterior patterning of the axial skeleton.

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    Growth and differentiation factor 11 (GDF11) is a transforming growth factor β family member that has been identified as the central player of anterior-posterior (A-P) axial skeletal patterning. Mice homozygous for Gdf11 deletion exhibit severe anterior homeotic transformations of the vertebrae and craniofacial defects. During early embryogenesis, Gdf11 is expressed predominantly in the primitive streak and tail bud regions, where new mesodermal cells arise. On the basis of this expression pattern of Gdf11 and the phenotype of Gdf11 mutant mice, it has been suggested that GDF11 acts to specify positional identity along the A-P axis either by local changes in levels of signaling as development proceeds or by acting as a morphogen. To further investigate the mechanism of action of GDF11 in the vertebral specification, we used a Cdx2-Cre transgene to generate mosaic mice in which Gdf11 expression is removed in posterior regions including the tail bud, but not in anterior regions. The skeletal analysis revealed that these mosaic mice display patterning defects limited to posterior regions where Gdf11 expression is deficient, whereas displaying normal skeletal phenotype in anterior regions where Gdf11 is normally expressed. Specifically, the mosaic mice exhibited seven true ribs, a pattern observed in wild-type (wt) mice (vs. 10 true ribs in Gdf11-/- mice), in the anterior axis and nine lumbar vertebrae, a pattern observed in Gdf11 null mice (vs. six lumbar vertebrae in wt mice), in the posterior axis. Our findings suggest that GDF11, rather than globally acting as a morphogen secreted from the tail bud, locally regulates axial vertebral patterning

    Metabolite profiles of live or dead carp (Cyprinus carpio) exposed to endosulfan sulfate using a targeted GC–MS analysis

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    Endosulfan sulfate is a major oxidized metabolite of endosulfan, which is a broad-spectrum chlorinated cyclodiene insecticide. In this study, GC–MS-based metabolic profiles of dead or live carp (Cyprinus carpio) exposed to endosulfan sulfate were investigated to elucidate the molecular toxicological effects of endosulfan sulfate on carp. Three different extraction methods were compared, and a 50% methanol solution was chosen as an efficient extraction method. Carp was exposed to endosulfan sulfate at a concentration of 8 ppb for 2 days. After exposure, the whole body of the fish was homogenized with liquid N2, extracted with the 50% methanol solution and dried before TMS derivatization for GC–MS analyses of the dead and live carp. A SIM (selected ion monitoring)-library of 373 metabolites was applied after GC–MS analysis to detect 146 metabolites in carp. Based on the one-way ANOVA results (P  1.5 or < 0.667), 30 metabolites were identified as biomarkers that were significantly different in the metabolic profiles among the control, dead and live carp. A metabolic pathway analysis using MetaboAnalyst 4.0 revealed that those biomarkers were important for the living or death response to endosulfan sulfate. The pathways indicated by the metabolic pathway analysis included starch and sucrose metabolism, galactose metabolism, glycerolipid metabolism, the citrate cycle and linoleic acid metabolism. These results suggest that these pathways underwent significant perturbations over the exposure period
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