scholarly journals Investigating the impact of aromatic ring substitutions on selectivity for a multimodal anion exchange prototype library

2018 ◽  
Vol 1569 ◽  
pp. 101-109 ◽  
Author(s):  
Julie Robinson ◽  
Mark A. Snyder ◽  
Chris Belisle ◽  
Jia-li Liao ◽  
Hong Chen ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Aromatic Ring ◽  
The Impact

scholarly journals Impact of anion exchange adsorbents on regional citrate anticoagulation

2020 ◽  
pp. 039139882094773
Author(s):  
Karin Strobl ◽  
Stephan Harm ◽  
Ute Fichtinger ◽  
Claudia Schildböck ◽  
Jens Hartmann
Keyword(s):  
Anion Exchange ◽  
Regional Citrate Anticoagulation ◽  
Liver Support ◽  
Anion Exchange Resins ◽  
Increased Risk ◽  
Extracorporeal Liver Support ◽  
Target Molecules ◽  
Exchange Resins ◽  
The Impact

Introduction: Heparin and citrate are commonly used anticoagulants in membrane/adsorption based extracorporeal liver support systems. However, anion exchange resins employed for the removal of negatively charged target molecules including bilirubin may also deplete these anticoagulants due to their negative charge. The aim of this study was to evaluate the adsorption of citrate by anion exchange resins and the impact on extracorporeal Ca2+ concentrations. Methods: Liver support treatments were simulated in vitro. Citrate and Ca2+ concentrations were measured pre and post albumin filter as well as pre and post adsorbents. In addition, batch experiments were performed to quantify citrate adsorption. Results: Pre albumin filter target Ca2+ concentrations were reached well with only minor deviations. Citrate was adsorbed by anion exchange resins, resulting in a higher Ca2+ concentration downstream of the adsorbent cartridges during the first hour of treatment. Conclusions: The anion exchange resin depletes citrate, leading to an increased Ca2+ concentration in the extracorporeal circuit, which may cause an increased risk of clotting during the first hour of treatment. An increase of citrate infusion during the first hour of treatment should therefore be considered to compensate for the adsorption of citrate.

The Impact of the Catalyst Layer Structure on the Performance of Anion Exchange Membrane Fuel Cell

2021 ◽  
pp. 139439
Author(s):  
Sungjun Kim ◽  
Min Her ◽  
Yongmin Kim ◽  
Chi-Yeong Ahn ◽  
Sungbin Park ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Anion Exchange ◽  
Layer Structure ◽  
Catalyst Layer ◽  
Anion Exchange Membrane ◽  
Exchange Membrane ◽  
The Impact

scholarly journals Role of methyl group number on SOA formation from aromatic hydrocarbons photooxidation under low NO<sub><i>x</i></sub> conditions

2015 ◽  
Vol 15 (21) ◽  
pp. 31153-31196 ◽  
Author(s):  
L. Li ◽  
P. Tang ◽  
S. Nakao ◽  
C.-L. Chen ◽  
D. R. Cocker III
Keyword(s):  
Aromatic Hydrocarbon ◽  
Aromatic Ring ◽  
Aromatic Hydrocarbons ◽  
Methyl Groups ◽  
Methyl Group ◽  
Group Number ◽  
The Impact ◽  
First Time ◽  
Linear Trends

Abstract. Substitution of methyl groups onto the aromatic ring determines the SOA formation from the aromatic hydrocarbon precursor. This study links the number of methyl groups on the aromatic ring to SOA formation from aromatic hydrocarbons photooxidation under low NOx conditions (HC / NO > 10 ppb C : ppb). Aromatic hydrocarbons with increasing numbers of methyl groups are systematically studied. SOA formation from pentamethylbenzene and hexamethylbenzene are reported for the first time. A decreasing SOA yield with increasing number of methyl groups is observed. Linear trends are found in both f44 vs. f43 and O / C vs. H / C for SOA from aromatic hydrocarbons with zero to six methyl groups. An SOA oxidation state predictive method based on benzene is used to examine the effect of added methyl groups on aromatic oxidation under low NOx conditions. Further, the impact of methyl group number on density and volatility of SOA from aromatic hydrocarbons is explored. Finally, a mechanism for methyl group impact on SOA formation is suggested. Overall, this work suggests as more methyl groups are attached on the aromatic ring, SOA products from these aromatic hydrocarbons become less oxidized per mass/carbon.

scholarly journals d-Galactose Decreases Anion Exchange Capability through Band 3 Protein in Human Erythrocytes

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 689
Author(s):  
Alessia Remigante ◽  
Rossana Morabito ◽  
Sara Spinelli ◽  
Vincenzo Trichilo ◽  
Saverio Loddo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Anion Exchange ◽  
Band 3 ◽  
Human Erythrocytes ◽  
Band 3 Protein ◽  
Expression Levels ◽  
Vitro Effect ◽  
The Impact

d-Galactose (d-Gal), when abnormally accumulated in the plasma, results in oxidative stress production, and may alter the homeostasis of erythrocytes, which are particularly exposed to oxidants driven by the blood stream. In the present investigation, the effect of d-Gal (0.1 and 10 mM, for 3 and 24 h incubation), known to induce oxidative stress, has been assayed on human erythrocytes by determining the rate constant of SO42− uptake through the anion exchanger Band 3 protein (B3p), essential to erythrocytes homeostasis. Moreover, lipid peroxidation, membrane sulfhydryl groups oxidation, glycated hemoglobin (% A1c), methemoglobin levels (% MetHb), and expression levels of B3p have been verified. Our results show that d-Gal reduces anion exchange capability of B3p, involving neither lipid peroxidation, nor oxidation of sulfhydryl membrane groups, nor MetHb formation, nor altered expression levels of B3p. d-Gal-induced %A1c, known to crosslink with B3p, could be responsible for rate of anion exchange alteration. The present findings confirm that erythrocytes are a suitable model to study the impact of high sugar concentrations on cell homeostasis; show the first in vitro effect of d-Gal on B3p, contributing to the understanding of mechanisms underlying an in vitro model of aging; demonstrate that the first impact of d-Gal on B3p is mediated by early Hb glycation, rather than by oxidative stress, which may be involved on a later stage, possibly adding more knowledge about the consequences of d-Gal accumulation.

scholarly journals Carbonate Dynamics and Opportunities With Low Temperature, Anion Exchange Membrane-Based Electrochemical Carbon Dioxide Separators

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
William A. Rigdon ◽  
Travis J. Omasta ◽  
Connor Lewis ◽  
Michael A. Hickner ◽  
John R. Varcoe ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Anion Exchange ◽  
Co2 Flux ◽  
Anion Exchange Membrane ◽  
Department Of Energy ◽  
Co2 Separation ◽  
Transport Pathway ◽  
Promising Alternative ◽  
Exchange Membrane ◽  
The Impact

Fossil fuel power plants are responsible for a significant portion of anthropogenic atmospheric carbon dioxide (CO2) and due to concerns over global climate change, finding solutions that significantly reduce emissions at their source has become a vital concern. When oxygen (O2) is reduced along with CO2 at the cathode of an anion exchange membrane (AEM) electrochemical cell, carbonate and bicarbonate are formed which are transported through electrolyte by migration from the cathode to the anode where they are oxidized back to CO2 and O2. This behavior makes AEM-based devices scientifically interesting CO2 separation devices or “electrochemical CO2 pumps.” Electrochemical CO2 separation is a promising alternative to the state-of-the-art solvent-based methods because the cells operate at low temperatures and scale with surface area, not volume, suggesting that the industrial electrochemical systems could be more compact than amine sorption technologies. In this work, we investigate the impact of the CO2 separator cell potential on the CO2 flux, carbonate transport mechanism, and process costs. The applied electrical current and CO2 flux showed a strong correlation that was both stable and reversible. The dominant anion transport pathway, carbonate versus bicarbonate, undergoes a shift from carbonate to mixed carbonate/bicarbonate with increased potential. A preliminary techno-economic analysis shows that despite the limitations of present cells, there is a clear pathway to meet the U.S. Department of Energy (DOE) 2025 and 2035 targets for power plant retrofit CO2 capture systems through materials and systems-level advances.

Cycloproparenyl anions: From models to real systems

2005 ◽  
Vol 77 (11) ◽  
pp. 1835-1850 ◽  
Author(s):  
Mirjana Eckert-Maksic ◽  
Zoran Glasovac
Keyword(s):  
Aromatic Ring ◽  
Linear Extension ◽  
Resonance Effect ◽  
Lone Pair ◽  
Membered Ring ◽  
Electron Interaction ◽  
Anionic Center ◽  
Cyano Groups ◽  
Opposing Effects ◽  
The Impact

An overview of our recent work on cycloproparenyl anions is given. Preparation, the electronic structure, and the properties of the progenitor of the series, cyclopropabenzenyl anion, are discussed. It is shown that the cyclopropabenzenyl anion is by ca. 145 kJ mol-1 more stable than the parent cyclopropenyl anion according to results of the MP2/6-31+G(d) calculations. This finding was attributed to a delicate balance of two opposing effects: (a) propensity of the aromatic ring to alleviate unfavorable 4π electron interaction within the three-membered ring by the anionic resonance effect and (b) a pyramidalization of the anionic center, which tends to maximize the s-character of the lone pair. We have also shown that stability of the cyclopropabenzenyl anion could be considerably enhanced by substitution of the aromatic ring with fluorine and cyano groups, as well as by a linear extension of the aromatic backbone. Finally, the impact of the fusion of additional cyclopropenyl ring to the benzene moiety to acidity of the benzylic position in cyclopropabenzene is discussed.

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