Anchoring Water Soluble Phosphotungstic Acid by Hybrid Fillers to Construct Three-Dimensional Proton Transport Networks

Phosphotungstic acid (HPW)-filled composite proton exchange membranes possess high proton conductivity under low relative humidity (RH). However, the leaching of HPW limits their wide application. Herein, we propose a novel approach for anchoring water soluble phosphotungstic acid (HPW) by polydopamine (PDA) coated graphene oxide and halloysite nanotubes (DGO and DHNTs) in order to construct hybrid three-dimensional proton transport networks in a sulfonated poly(ether ether ketone) (SPEEK) membrane. The introduction of PDA on the surfaces of the hybrid fillers could provide hydroxyl groups and secondary amine groups to anchor HPW, resulting in the uniform dispersion of HPW in the SPEEK matrix. The SPEEK/DGO/DHNTs/HPW (90/5/5/60) composite membrane exhibited higher water uptake and much better conductivity than the SPEEK membrane at low relative humidity. The best conductivity reached wass 0.062 S cm−1 for the composite membrane, which is quite stable during the water immersion test.

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Water Dynamics and Proton-Transport Mechanisms of Nafion 117/Phosphotungstic Acid Composite Membrane: A Molecular Dynamics Study

ChemPhysChem ◽

10.1002/cphc.201700725 ◽

2017 ◽

Vol 18 (23) ◽

pp. 3485-3497 ◽

Cited By ~ 3

Author(s):

Saeed Akbari ◽

Mohammad Taghi Hamed Mosavian ◽

Ali Ahmadpour ◽

Fatemeh Moosavi

Keyword(s):

Molecular Dynamics ◽

Composite Membrane ◽

Proton Transport ◽

Phosphotungstic Acid ◽

Water Dynamics ◽

Transport Mechanisms

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A polyoxometalate coupled graphene oxide–Nafion composite membrane for fuel cells operating at low relative humidity

Journal of Materials Chemistry A ◽

10.1039/c5ta00182j ◽

2015 ◽

Vol 3 (15) ◽

pp. 8148-8155 ◽

Cited By ~ 86

Author(s):

Yong Kim ◽

Kriangsak Ketpang ◽

Shayapat Jaritphun ◽

Jun Seo Park ◽

Sangaraju Shanmugam

Keyword(s):

Graphene Oxide ◽

Fuel Cells ◽

Fuel Cell ◽

Relative Humidity ◽

Power Density ◽

Composite Membrane ◽

Phosphotungstic Acid ◽

Nafion Membrane

A phosphotungstic acid coupled GO–Nafion membrane showed an enhanced fuel cell power density at 80 °C under 20% RH, compared with Nafion-212.

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Cyclodextrin Polymers and Cyclodextrin-Containing Polysaccharides for Water Remediation

Polysaccharides ◽

10.3390/polysaccharides2010002 ◽

2021 ◽

Vol 2 (1) ◽

pp. 16-38

Author(s):

Tânia F. Cova ◽

Dina Murtinho ◽

Roberto Aguado ◽

Alberto A. C. C. Pais ◽

Artur J. M. Valente

Keyword(s):

Aqueous Media ◽

Three Dimensional ◽

Water Soluble ◽

Water Remediation ◽

Dimensional Structure ◽

Chemical Pollution ◽

Hydroxyl Groups ◽

Interaction Patterns ◽

Polycarboxylic Acids ◽

Sorbent Materials

Chemical pollution of water has raised great concerns among citizens, lawmakers, and nearly all manufacturing industries. As the legislation addressing liquid effluents becomes more stringent, water companies are increasingly scrutinized for their environmental performance. In this context, emergent contaminants represent a major challenge, and the remediation of water bodies and wastewater demands alternative sorbent materials. One of the most promising adsorbing materials for micropolluted water environments involves cyclodextrin (CD) polymers and cyclodextrin-containing polysaccharides. Although cyclodextrins are water-soluble and, thus, unusable as adsorbents in aqueous media, they can be feasibly polymerized by using different crosslinkers such as epichlorohydrin, polycarboxylic acids, and glutaraldehyde. Likewise, with those coupling agents or after substituting hydroxyl groups with more reactive moieties, cyclodextrin units can be covalently attached to a pre-existing polysaccharide. In this direction, the functionalization of chitosan, cellulose, carboxymethyl cellulose, and other carbohydrate polymers with CDs is vastly found in the literature. For the system containing CDs to be used for remediation purposes, there are benefits from a synergy that arises from (i) the ability of CD units to interact selectively with a broad spectrum of molecules, forming inclusion complexes and higher-order supramolecular assemblies, (ii) the functional groups of the crosslinker comonomers, (iii) the three-dimensional structure of the crosslinked network, and/or (iv) the intrinsic characteristics of the polysaccharide backbone. In view of the most recent contributions regarding CD-based copolymers and CD-containing polysaccharides, this review discusses their performance as adsorbents in micropolluted water environments, as well as their interaction patterns, addressing the influence of their structural and physicochemical properties and their functionalization.

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Measurement of proteolysis in cheese: relationship between phosphotungstic acid-soluble N fraction by Kjeldahl and 2,4,6- trinitrobenzenesulphonic acid-reactive groups in water-soluble N

Journal of Dairy Research ◽

10.1017/s0022029900030880 ◽

1994 ◽

Vol 61 (3) ◽

pp. 437-440 ◽

Cited By ~ 12

Author(s):

Yvette Bouton ◽

Remy Grappin

Keyword(s):

Amino Acids ◽

Free Amino Acids ◽

Free Amino ◽

Phosphotungstic Acid ◽

Water Soluble ◽

Hydroxyl Groups ◽

Amino Groups ◽

Reactive Groups ◽

Primary Amino

Free amino groups produced during cheese ripening are used to indicate the extent of cheese proteolysis. Several studies have shown a high correlation between the level of free amino acids and the flavour of Gouda (Aston et al. 1983) or Comté (Grappin & Berdagué, 1989). Measurement of the level of free amino acids seems useful for the investigation of flavour chemistry in cheese (Lemieux et al. 1990). The determination of N fractions is often used to estimate the degree of proteolysis in cheese, but since this procedure is laborious and time consuming several attempts have been made to replace it by more rapid methods (Ardö & Meisel, 1991). Since its introduction by Satake et al. (1960), the 2,4,6-trinitrobenzenesulphonic acid (TNBS) method has been widely used for the determination of free amino groups. Because TNBS does not react with the imino groups of histidine and proline or the hydroxyl groups of tyrosine, serine or threonine, it has been accepted as a selective reagent for primary amino groups (Burger, 1974). Measurement of N by Kjeldahl in the phosphotungstic acid (PTA)–sulphuric acid extract (Gripon et al. 1975) estimates the N of free amino acids and low molecular mass peptides. The purpose of this study was to compare the TNBS and PTA-soluble N methods in order to find out whether the TNBS procedure can replace that of PTA-soluble N in the determination of a cheese proteolysis index.

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The Potential Migrated Mechanism of Water-Soluble Components in Pellets Prepared by Wet Extrusion/Spheronization: Effect of Drying Rate

Current Drug Delivery ◽

10.2174/1567201817666201124113741 ◽

2020 ◽

Vol 17 ◽

Author(s):

Bingwei Wang ◽

Jianping Liu ◽

Zhenghua Li ◽

Yulong Xia ◽

Shuangshuang Zhang ◽

...

Keyword(s):

Relative Humidity ◽

Water Soluble ◽

In Vitro Dissolution ◽

Drying Rate ◽

Scanning Calorimetry ◽

Drying Temperature ◽

Wet Extrusion ◽

Extrusion Spheronization ◽

Soluble Components

Background: At present, there were numerous researches on the migration of components in tablets and granules, the investigation in the pharmaceutical literatrue concerning the effect of drying rate on the migration of water-soluble components of pellets was limited. Temperature and relative humidity (RH) were crucial parameters during the drying process which was an essential step in the preparation of pellets via wet extrusion/spheronization. To quantify these variables, the water loss percentage of pellets per minute was defined as drying rate. Objective: The study aimed to investigate the influence of drying rate on the migration of water-soluble components in wet pellets and the potential migrated mechanism. Methods: The pellets containing tartrazine as a water-soluble model drug and microcrystalline cellulose as a matrix former were prepared by extrusion/spheronization and dried at four different drying temperature and relative humidity. Afterward, the extent of migrated tartrazine was assessed regarding appearance, in-vitro dissolution test, Differential Scanning Calorimetry, X-Ray Powder Diffraction, Attenuated total reflectance Fourier transform infrared spectroscopy and Confocal Raman Mapping. Results: Results demonstrated that red spots of tartrazine appeared on the surface of pellets and more than 40% tartrazine were burst released within 5 minutes when pellets dried at 60℃/RH 10%. While pellets dried at 40℃/RH 80%, none of these aforementioned phenomena was observed. Conclusion: In conclusion, the faster drying rate was, the more tartrazine migrated to the exterior of pellets. Adjusting drying temperature and relative humidity appropriately could inhibit the migration of water-soluble components within wet extrusion/spheronization pellets.

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Fibrillar pharmacology of functionalized nanocellulose

Scientific Reports ◽

10.1038/s41598-020-79592-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sam Wong ◽

Simone Alidori ◽

Barbara P. Mello ◽

Bryan Aristega Almeida ◽

David Ulmert ◽

...

Keyword(s):

Aspect Ratio ◽

Fluorescent Dyes ◽

Pharmacokinetic Profile ◽

Water Soluble ◽

Size Exclusion ◽

Hydroxyl Groups ◽

Target Tissue ◽

Exclusion Chromatography ◽

Specific Accumulation

AbstractCellulose nanocrystals (CNC) are linear organic nanomaterials derived from an abundant naturally occurring biopolymer resource. Strategic modification of the primary and secondary hydroxyl groups on the CNC introduces amine and iodine group substitution, respectively. The amine groups (0.285 mmol of amine per gram of functionalized CNC (fCNC)) are further reacted with radiometal loaded-chelates or fluorescent dyes as tracers to evaluate the pharmacokinetic profile of the fCNC in vivo. In this way, these nanoscale macromolecules can be covalently functionalized and yield water-soluble and biocompatible fibrillar nanoplatforms for gene, drug and radionuclide delivery in vivo. Transmission electron microscopy of fCNC reveals a length of 162.4 ± 16.3 nm, diameter of 11.2 ± 1.52 nm and aspect ratio of 16.4 ± 1.94 per particle (mean ± SEM) and is confirmed using atomic force microscopy. Size exclusion chromatography of macromolecular fCNC describes a fibrillar molecular behavior as evidenced by retention times typical of late eluting small molecules and functionalized carbon nanotubes. In vivo, greater than 50% of intravenously injected radiolabeled fCNC is excreted in the urine within 1 h post administration and is consistent with the pharmacological profile observed for other rigid, high aspect ratio macromolecules. Tissue distribution of fCNC shows accumulation in kidneys, liver, and spleen (14.6 ± 6.0; 6.1 ± 2.6; and 7.7 ± 1.4% of the injected activity per gram of tissue, respectively) at 72 h post-administration. Confocal fluorescence microscopy reveals cell-specific accumulation in these target tissue sinks. In summary, our findings suggest that functionalized nanocellulose can be used as a potential drug delivery platform for the kidneys.

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Identification and functional analysis of cadmium-binding protein in the visceral mass of Crassostrea gigas

Scientific Reports ◽

10.1038/s41598-021-90882-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Zehua Zheng ◽

Kazuhiro Kawakami ◽

Dingkun Zhang ◽

Lumi Negishi ◽

Mohamed Abomosallam ◽

...

Keyword(s):

Crassostrea Gigas ◽

Metal Ion ◽

Defense Mechanisms ◽

Three Dimensional ◽

Tryptophan Fluorescence ◽

Water Soluble ◽

Titration Calorimetry ◽

Visceral Mass ◽

The Pacific ◽

Liquid Chromatography Tandem Mass

AbstractThe Pacific oyster, Crassostrea gigas, is a traditional food worldwide. The soft body of the oyster can easily accumulate heavy metals such as cadmium (Cd). To clarify the molecular mechanism of Cd accumulation in the viscera of C. gigas, we identified Cd-binding proteins. 5,10,15,20-Tetraphenyl-21H,23H-porphinetetrasulfonic acid, disulfuric acid, tetrahydrate, and Cd-binding competition experiments using immobilized metal ion affinity chromatography revealed the binding of water-soluble high molecular weight proteins to Cd, including C. gigas protein disulfide isomerase (cgPDI). Liquid chromatography–tandem mass spectrometry (LC–MS/MS) analyses revealed two CGHC motifs in cgPDI. The binding between Cd and rcgPDI was confirmed through a Cd-binding experiment using the TPPS method. Isothermal titration calorimetry (ITC) revealed the binding of two Cd ions to one molecule of rcgPDI. Circular dichroism (CD) spectrum and tryptophan fluorescence analyses demonstrated that the rcgPDI bound to Cd. The binding markedly changed the two-dimensional or three-dimensional structures. The activity of rcgPDI measured by a PDI Activity Assay Kit was more affected by the addition of Cd than by human PDI. Immunological analyses indicated that C. gigas contained cgPDI at a concentration of 1.0 nmol/g (viscera wet weight). The combination of ITC and quantification results revealed that Cd-binding to cgPDI accounted for 20% of the total bound Cd in the visceral mass. The findings provide new insights into the defense mechanisms of invertebrates against Cd.

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Approach to Quantify the Impact of Disruptions on Traffic Conditions using Dynamic Weighted Resilience Metrics of Transport Networks

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198121998663 ◽

2021 ◽

pp. 036119812199866 ◽

Cited By ~ 1

Author(s):

Elise Henry ◽

Angelo Furno ◽

Nour-Eddin El Faouzi

Keyword(s):

Three Dimensional ◽

Traffic Load ◽

Transport Networks ◽

Traffic Conditions ◽

Probe Vehicle ◽

Vehicle Data ◽

Network Operations ◽

Network States ◽

The Impact ◽

Proper Operation

Transport networks are essential for societies. Their proper operation has to be preserved to face any perturbation or disruption. It is therefore of paramount importance that the modeling and quantification of the resilience of such networks are addressed to ensure an acceptable level of service even in the presence of disruptions. The paper aims at characterizing network resilience through weighted degree centrality. To do so, a real dataset issued from probe vehicle data is used to weight the graph by the traffic load. In particular, a set of disrupted situations retrieved from the study dataset is analyzed to quantify the impact on network operations. Results demonstrate the ability of the proposed metrics to capture traffic dynamics as well as their utility for quantifying the resilience of the network. The proposed methodology combines different metrics from the complex networks theory (i.e., heterogeneity, density, and symmetry) computed on temporal and weighted graphs. Time-varying traffic conditions and disruptions are analyzed by providing relevant insights on the network states via three-dimensional maps.

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Two-photon polymerization nanolithography technology for fabrication of stimulus-responsive micro/nano-structures for biomedical applications

Nanotechnology Reviews ◽

10.1515/ntrev-2020-0073 ◽

2020 ◽

Vol 9 (1) ◽

pp. 1118-1136

Author(s):

Zhenjia Huang ◽

Gary Chi-Pong Tsui ◽

Yu Deng ◽

Chak-Yin Tang

Keyword(s):

Biomedical Applications ◽

Three Dimensional ◽

Water Soluble ◽

Fabrication Technology ◽

Nano Fabrication ◽

Two Photon ◽

Nano Structures ◽

Wide Range ◽

Stimulus Responsive ◽

Two Photon Polymerization

AbstractMicro/nano-fabrication technology via two-photon polymerization (TPP) nanolithography is a powerful and useful manufacturing tool that is capable of generating two dimensional (2D) to three dimensional (3D) arbitrary micro/nano-structures of various materials with a high spatial resolution. This technology has received tremendous interest in cell and tissue engineering and medical microdevices because of its remarkable fabrication capability for sophisticated structures from macro- to nano-scale, which are difficult to be achieved by traditional methods with limited microarchitecture controllability. To fabricate precisely designed 3D micro/nano-structures for biomedical applications via TPP nanolithography, the use of photoinitiators (PIs) and photoresists needs to be considered comprehensively and systematically. In this review, widely used commercially available PIs are first discussed, followed by elucidating synthesis strategies of water-soluble initiators for biomedical applications. In addition to the conventional photoresists, the distinctive properties of customized stimulus-responsive photoresists are discussed. Finally, current limitations and challenges in the material and fabrication aspects and an outlook for future prospects of TPP for biomedical applications based on different biocompatible photosensitive composites are discussed comprehensively. In all, this review provides a basic understanding of TPP technology and important roles of PIs and photoresists for fabricating high-precision stimulus-responsive micro/nano-structures for a wide range of biomedical applications.

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