scholarly journals Interaction-based ion selectivity exhibited by self-assembled, cross-linked zwitterionic copolymer membranes

2021 ◽  
Vol 118 (37) ◽  
pp. e2022198118 ◽  
Author(s):  
Samuel J. Lounder ◽  
Ayse Asatekin
Keyword(s):  
Transport Model ◽  
Ion Selectivity ◽  
Membrane System ◽  
Dominant Mode ◽  
Salt Flux ◽  
Filtration Membranes ◽  
Wide Range ◽  
High Fluoride ◽  
Self Assembled ◽  
Mode Of Transport

Water filtration membranes with advanced ion selectivity are urgently needed for resource recovery and the production of clean drinking water. This work investigates the separation capabilities of cross-linked zwitterionic copolymer membranes, a self-assembled membrane system featuring subnanometer zwitterionic nanochannels. We demonstrate that selective zwitterion–anion interactions simultaneously control salt partitioning and diffusivity, with the permeabilities of NaClO4, NaI, NaBr, NaCl, NaF, and Na2SO4 spanning roughly three orders of magnitude over a wide range of feed concentrations. We model salt flux using a one-dimensional transport model based on the Maxwell–Stefan equations and show that diffusion is the dominant mode of transport for 1:1 sodium salts. Differences in zwitterion–Cl− and zwitterion–F− interactions granted these membranes with the ultrahigh Cl−/F− permselectivity (PCl-/PF- = 24), enabling high fluoride retention and high chloride passage even from saline mixtures of NaCl and NaF.

Celiac Disease in Kosovar Albanian Children: Evaluation of Clinical Features and Diagnosis

2020 ◽  
Vol 16 (3) ◽  
pp. 241-247
Author(s):  
Atifete Ramosaj-Morina ◽  
Alije Keka-Sylaj ◽  
Arbana Baloku Zejnullahu ◽  
Lidvana Spahiu ◽  
Virgjina Hasbahta ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Disease Onset ◽  
Clinical Manifestations ◽  
Gastrointestinal Symptoms ◽  
Dominant Mode ◽  
Primary School Children ◽  
Cross Sectional ◽  
Classical Form ◽  
Wide Range ◽  
The Mean

Background: Celiac disease is an immune-mediated disorder characterized by variable clinical manifestations, specific antibodies, HLA-DQ2/DQ8 haplotypes, and enteropathy. Objectives: The aim of this study was to present the clinical spectrum and patterns of celiac disease in Kosovar Albanian children. Methods: A cross-sectional retrospective study was performed with Albanian children aged 0-18 years, treated for celiac disease in the Pediatric Clinic, University Clinical Center of Kosovo from 2005 to 2016. Results: During the study period, 63 children were treated for celiac disease. The mean age at diagnosis was 5.5 years (SD ± 3.31). The mean age at celiac disease onset was 3.3 years (SD ± 2.02), while the mean delay from the first symptoms indicative of celiac disease to diagnosis was 2.2 years (SD ± 2.09). More than 70% of the patients were diagnosed in the first 7 years of life, mainly presented with gastrointestinal symptoms, while primary school children and adolescents mostly showed atypical symptoms (p<0.001). The classical form of celiac disease occurred in 78% of the cases. Sixty (95%) patients carried HLA-DQ2.5, DQ2.2 and/or HLA-DQ8 heterodimers, and only three of them tested negative. Conclusions: Kosovo, as the majority of developing countries, is still facing the classical form of celiac disease as the dominant mode of presentation; as a result, most children with other forms of the celiac disease remain undiagnosed. : Physicians should be aware of the wide range of clinical presentations and utilize low testing thresholds in order to prevent potential long-term problems associated with untreated celiac disease.

scholarly journals In Vitro Cellular Uptake Studies of Self-Assembled Fluorinated Nanoparticles Labelled with Antibodies

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1906
Author(s):  
Mona Atabakhshi-Kashi ◽  
Mónica Carril ◽  
Hossein Mahdavi ◽  
Wolfgang J. Parak ◽  
Carolina Carrillo-Carrion ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cellular Uptake ◽  
Hydrophobic Interactions ◽  
Intrinsic Properties ◽  
Wide Range ◽  
Self Assembled ◽  
Uptake Studies ◽  
Targeting Ability ◽  
Fluorinated Nanoparticles

Nanoparticles (NPs) functionalized with antibodies (Abs) on their surface are used in a wide range of bioapplications. Whereas the attachment of antibodies to single NPs to trigger the internalization in cells via receptor-mediated endocytosis has been widely studied, the conjugation of antibodies to larger NP assemblies has been much less explored. Taking into account that NP assemblies may be advantageous for some specific applications, the possibility of incorporating targeting ligands is quite important. Herein, we performed the effective conjugation of antibodies onto a fluorescent NP assembly, which consisted of fluorinated Quantum Dots (QD) self-assembled through fluorine–fluorine hydrophobic interactions. Cellular uptake studies by confocal microscopy and flow cytometry revealed that the NP assembly underwent the same uptake procedure as individual NPs; that is, the antibodies retained their targeting ability once attached to the nanoassembly, and the NP assembly preserved its intrinsic properties (i.e., fluorescence in the case of QD nanoassembly).

scholarly journals Water Filtration Membranes Based on Non-Woven Cellulose Fabrics: Effect of Nanopolysaccharide Coatings on Selective Particle Rejection, Antifouling, and Antibacterial Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1752
Author(s):  
Blanca Jalvo ◽  
Andrea Aguilar-Sanchez ◽  
Maria-Ximena Ruiz-Caldas ◽  
Aji P. Mathew
Keyword(s):  
Cellulose Nanofibers ◽  
Antibacterial Properties ◽  
Surface Characteristics ◽  
Water Filtration ◽  
Separation Performance ◽  
Nonwoven Fabrics ◽  
Filtration Membranes ◽  
Wide Range ◽  
Dry Conditions ◽  
Cellulose Fabrics

This article presents a comparative study of the surface characteristics and water purification performance of commercially available cellulose nonwoven fabrics modified, via cast coating, with different nano-dimensioned bio-based carbohydrate polymers, viz. cellulose nanocrystals (CNC), TEMPO-oxidized cellulose nanofibers (T-CNF), and chitin nanocrystals (ChNC). The surface-modified nonwoven fabrics showed an improvement in wettability, surface charge modification, and a slight decrease of maximum pore size. The modification improved the water permeance in most of the cases, enhanced the particle separation performance in a wide range of sizes, upgraded the mechanical properties in dry conditions, and showed abiotic antifouling capability against proteins. In addition, T-CNF and ChNC coatings proved to be harmful to the bacteria colonizing on the membranes. This simple surface impregnation approach based on green nanotechnology resulted in highly efficient and fully bio-based high-flux water filtration membranes based on commercially available nonwoven fabrics, with distinct performance for particle rejection, antifouling and antibacterial properties.

scholarly journals Self-Assembled Hierarchical CuxO@C18H36O2 Nanoflakes for Superior Fenton-like Catalysis over a Wide Range of pH

ACS Omega ◽  
2021 ◽  
Author(s):  
Ratul Rehman ◽  
Sudip Kumar Lahiri ◽  
Ashraful Islam ◽  
Peng Wei ◽  
Yue Xu
Keyword(s):  
Wide Range ◽  
Self Assembled

Sulfuric acid vapor and sulfur dioxide in the atmosphere of Venus as observed by the Venus Express Radio Science Experiment VeRa

2021 ◽  
Author(s):  
Janusz Oschlisniok ◽  
Bernd Häusler ◽  
Martin Pätzold ◽  
Silvia Tellmann ◽  
Michael Bird
Keyword(s):  
Sulfuric Acid ◽  
Transport Model ◽  
Lower Atmosphere ◽  
Local Times ◽  
Acid Vapor ◽  
Radio Science ◽  
X Band ◽  
Wide Range ◽  
Venus Express ◽  
Atmosphere Of Venus

&lt;p&gt;The main cloud deck within Venus' atmosphere, which covers the entire planet between approx. 50 and 70 km altitude, is believed to consist mostly of liquid sulfuric acid. The temperature below the main clouds is high enough to evaporate the H2SO4 droplets into gaseous sulfuric acid forming a haze layer which extends to altitudes as deep as 35 km. Gaseous sulfuric acid in Venus&amp;#8217; lower atmosphere is responsible for a strong absorption of radio waves as seen in Mariner, Pioneer Venus, Magellan and Venera radio science observations. Radio wave absorption measurements can be used to derive the amount of H2SO4 in Venus&amp;#8217; atmosphere. The radio science experiment VeRa onboard Venus Express probed the atmosphere of Venus between 2006 and 2014 with radio signals at 13 cm (S-band) and 3.6 cm (X-band) wavelengths. The orbit of the Venus Express spacecraft allowed to sound the atmosphere over a wide range of latitudes and local times providing a global picture of the sulfuric acid vapor distribution. We present the global H2SO4(g) distribution derived from the X-band radio signal attenuation for the time of the entire Venus Express mission. The observation is compared with results obtained from a 2-D transport model. The VeRa observations were additionally used to estimate the abundance of SO2 near the cloud bottom. The global distribution of SO2 at these altitudes is presented and compared with results obtained from other experiments. Eight years of VEX observation allow to study the long-term evolution of H2SO4 and SO2. The latter is presented for the northern polar region.&lt;/p&gt;

scholarly journals Size matters: Size Dependency of Gold Nanoparticles Interacting with Model Membranes

2019 ◽  
Author(s):  
Claudia Contini ◽  
James W. Hindley ◽  
Tom Macdonald ◽  
Joseph Barritt ◽  
Oscar Ces ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Lipid Bilayers ◽  
Lipid Membrane ◽  
Rapid Development ◽  
Membrane System ◽  
Size Dependent ◽  
Research Fields ◽  
Large Unilamellar Vesicles ◽  
Wide Range ◽  
Experimental Characterisation

<p><b>The rapid development of nanomaterials has led to an increase in the number and variety of engineered nanomaterials (ENMs) in the environment. Gold nanoparticles (AuNPs) are an example of a commonly studied ENM whose highly tailorable properties have generated significant interest through a wide range of research fields. In the present work, we report the first qualitative as well as quantitative experimental characterisation of the AuNP-membrane interaction. We investigate the interactions between citrate-stabilised AuNPs (diameters 5, 10, 25, 35, 50, 60 nm) and large unilamellar vesicles (LUVs) acting as a model membrane system. LUVs were prepared in two different formulations using 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) and 1,2-dileoyl-sn-glycero-3-phosphocholine (DOPC). Our results show that the interaction between AuNPs and LUVs is size dependent; in particular, we reveal the existence of two AuNP’s critical diameters which determine the fate of AuNPs in contact with a lipid membrane. The results provide a new understanding of the size dependent interaction between AuNPs and lipid bilayers of direct relevance to nanotoxicology and to the design of NP vectors.</b></p>

Modeling of Turbulent Flows Through the Annular Channel with Eccentricity and Rotating Inner Cilinder

2012 ◽  
Vol 7 (4) ◽  
pp. 79-86
Author(s):  
Evgeny Podryabinkin ◽  
Valeriy Rudyak
Keyword(s):  
Pressure Drop ◽  
Turbulent Flows ◽  
Transport Model ◽  
Reverse Flow ◽  
Axial Flow ◽  
Annular Channel ◽  
Rotational Flow ◽  
Concentric Annulus ◽  
Cylindrical Annulus ◽  
Wide Range

In this paper fully developed turbulent flows of Newtonian fluid in cylindrical annulus with eccentricity and rotating inner cylinder has been systematically studied. Modeling has been performed on the base of Menter Shear Transport model of turbulence in a wide range of Reynolds numbers, eccentricity, and radii ratio. As the result dependencies of flow field and pressure drop along the channel on geometrical and flow parameters have been found. It was shown that flow characteristics and dependence of the pressure drop are determined by which flow axial or rotational dominates and caused generation of turbulence. When rotational flow dominates the dependence of the pressure drop is almost linear. When axial flow dominates rotation practically has no impact on the pressure drop in concentric annulus. Appearance of the reverse flow in eccentric channel has a major impact on the pressure drop. In case when rotational flow dominates, appearance of the reverse flow is accompanied by threshold flow restructuring at some critical value of eccentricity. A correlation for determination of the pressure drop in various regimes has been developed for the case of concentric annulus

Novel syntaxin gene sequences from Giardia, Trypanosoma and algae: implications for the ancient evolution of the eukaryotic endomembrane system

2002 ◽  
Vol 115 (8) ◽  
pp. 1635-1642 ◽  
Author(s):  
Joel B. Dacks ◽  
W. Ford Doolittle
Keyword(s):  
Protein Interactions ◽  
Calcium Binding ◽  
Parallel Evolution ◽  
Membrane System ◽  
Compartment System ◽  
Eukaryotic Diversity ◽  
Wide Range ◽  
Membrane Compartment ◽  
Isoleucine Residue

SNAP receptors or SNARES are crucial components of the intracellular membrane system of eukaryotes. The syntaxin family of SNAREs have been shown to have roles in neurotransmission, vesicular transport, membrane fusion and even internal membrane compartment reconstruction. While syntaxins and SNAREs in general have been well characterized in mammalian and yeast models, little is known about their overall distribution across eukaryotic diversity or about the evolution of the syntaxin gene family. By combining bioinformatic,molecular biological and phylogenetic approaches, we demonstrate that various syntaxin homologs are not only present in `eukaryotic crown taxa' but across a wide range of eukaryotic lineages. The alignment of evolutionarily diverse syntaxin paralogs shows that an isoleucine residue critical to nSec1—syntaxin complex formation and the characteristic syntaxin glutamine residue are nearly universally conserved, implying a general functional importance for these residues. Other identified functional residues involved in botulism toxicity and calcium-binding-protein interactions are also compared. The presence of Golgi-related syntaxins in the intestinal parasite Giardia intestinalis provides further evidence for a cryptic Golgi in this `adictyosomal' taxon, and another likely case of secondary reduction in this parasite. The phylogeny of syntaxins shows a number of nested duplications, including a case of parallel evolution in the plasma membrane-associated syntaxins, and ancestral duplications in the other syntaxin paralogs. These speak to ancient events in the evolution of the syntaxin system and emphasize the universal role of the syntaxins in the eukaryotic intracellular compartment system.

scholarly journals Multiple Kinetic Parameterization in a Reactive Transport Model Using the Exchange Monte Carlo Method

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 579 ◽  
Author(s):  
Ryosuke Oyanagi ◽  
Atsushi Okamoto ◽  
Noriyoshi Tsuchiya
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Reactive Transport ◽  
Transport Model ◽  
Synthetic Data ◽  
Solution Chemistry ◽  
Rock Interaction ◽  
Reactive Transport Model ◽  
Reaction Rate Constants ◽  
Wide Range

Water–rock interaction in surface and subsurface environments occurs in complex multicomponent systems and involves several reactions, including element transfer. Such kinetic information is obtained by fitting a forward model into the temporal evolution of solution chemistry or the spatial pattern recorded in the rock samples, although geochemical and petrological data are essentially sparse and noisy. Therefore, the optimization of kinetic parameters sometimes fails to converge toward the global minimum due to being trapped in a local minimum. In this study, we simultaneously present a novel framework to estimate multiple reaction-rate constants and the diffusivity of aqueous species from the mineral distribution pattern in a rock by using the reactive transport model coupled with the exchange Monte Carlo method. Our approach can estimate both the maximum likelihood and error of each parameter. We applied the method to the synthetic data, which were produced using a model for silica metasomatism and hydration in the olivine–quartz–H2O system. We tested the robustness and accuracy of our method over a wide range of noise intensities. This methodology can be widely applied to kinetic analyses of various kinds of water–rock interactions.

Sensitization of the SST Turbulence Model to Rotation and Curvature by Applying the Spalart–Shur Correction Term

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Pavel E. Smirnov ◽  
Florian R. Menter
Keyword(s):  
Turbulent Flows ◽  
Turbulence Model ◽  
Transport Model ◽  
Correction Term ◽  
Computational Cost ◽  
Turbulence Models ◽  
Reynolds Stress Transport Model ◽  
Wide Range ◽  
Sst Model ◽  
The One

A rotation-curvature correction suggested earlier by Spalart and Shur (1997, “On the Sensitization of Turbulence Models to Rotation and Curvature,” Aerosp. Sci. Technol., 1(5), pp. 297–302) for the one-equation Spalart–Allmaras turbulence model is adapted to the shear stress transport model. This new version of the model (SST-CC) has been extensively tested on a wide range of both wall-bounded and free shear turbulent flows with system rotation and/or streamline curvature. Predictions of the SST-CC model are compared with available experimental and direct numerical simulations (DNS) data, on the one hand, and with the corresponding results of the original SST model and advanced Reynolds stress transport model (RSM), on the other hand. It is found that in terms of accuracy the proposed model significantly improves the original SST model and is quite competitive with the RSM, whereas its computational cost is significantly less than that of the RSM.

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