State of the art and prospects in the development of proton‐conducting perfluorinated membranes with short side chains: A review

2020 ◽  
Author(s):  
Oleg N. Primachenko ◽  
Elena A. Marinenko ◽  
Alexey S. Odinokov ◽  
Svetlana V. Kononova ◽  
Yuri V. Kulvelis ◽  
...  
Keyword(s):  
State Of The Art ◽  
Side Chains ◽  
Short Side ◽  
Proton Conducting ◽  
Perfluorinated Membranes

Study on Preparation and Dispersion Effect of Polycarboxylate Superplasticizer with Broken Dentiform Structure

2011 ◽  
Vol 250-253 ◽  
pp. 984-989 ◽  
Author(s):  
Zhi Yong Liu ◽  
Chong Cui ◽  
Li Li
Keyword(s):  
Carboxylic Acid ◽  
Chemical Structure ◽  
Side Chain ◽  
Side Chains ◽  
Test Results ◽  
Dispersion Effect ◽  
Anionic Polymer ◽  
Short Side ◽  
Carboxylic Acid Groups ◽  
Radical Polymerisation

Based on the analysis of the chemical structure of polycarboxylate-type SPs grafted PEO side chains, as well as sulfonic and carboxylic acid groups, a kind of polycarboxylate-based SPs grafted varied PEO side chains were synthesized by using radical polymerisation techniques.The relative dispersing effectiveness of the SPs was evaluated in cement paste and concrete by measuring paste flow and concrete slumps. The test results indicat that the copolymers with shorter PEO side chains (with 9 and 14 EO units) give lower initial dispersing power but higher time retention,with the prolonging of PEO side chains the higher initial dispersing effect and the lower time retention can be received. The excellent dispersing property and time retention of synthesized SPs for cementious systems can be achieved by grafted long side chain(with 45 EO units) integrated with short side chain(9 or 14 EO) at the backbone of anionic polymer.

The Mobility of Tryptophan and Dansyl Fluorophores in Labelled Poly(N-ethylacrylamide) and Poly(N-ethylmethacrylamide)

1993 ◽  
Vol 58 (10) ◽  
pp. 2383-2395 ◽  
Author(s):  
František Mikeš ◽  
Drahomír Výprachtický ◽  
Jan Pecka
Keyword(s):  
Conformational Changes ◽  
High Viscosity ◽  
Side Chains ◽  
Fluorescence Depolarization ◽  
Polymer Backbone ◽  
Short Side ◽  
Low Viscosity ◽  
Viscosity Range ◽  
Methylene Groups ◽  
Intramolecular Association

The mobility of tryptophan fluorophore in N-butyl-Nα-acetyltryptophanamide and in side chain of labelled poly(N-ethylacrylamide) and poly(N-ethylmethacrylamide) was investigated by the fluorescence depolarization method. The mobility of the fluorophore in the low-molecular-weight model is much higher than in side chains of the polymers. Different steric hindrance by the polymer backbone can explain the higher mobility of the fluorophore in poly(N-ethylacrylamide) and in poly(N-ethylmethacrylamide). The mobility of 5-dimethylamino-1-naphthalenesulfonamide (dansyl) fluorophore in side chains of labelled poly(N-ethylmethacrylamide) in the high-viscosity range increases with increasing number of methylene groups in side chains. The low-viscosity range, the rate s of conformational changes in short side chains (n = 2 - 7) are approximately constant and significantly decrease in long side chains (n = 10, 12). The drop in the rates is probably due to intramolecular association of the long hydrophobic chains in water.

Proton conducting graft copolymers with tunable length and density of phosphonated side chains for fuel cell membranes

2014 ◽  
Vol 450 ◽  
pp. 362-368 ◽  
Author(s):  
Ivaylo Dimitrov ◽  
Shogo Takamuku ◽  
Katja Jankova ◽  
Patric Jannasch ◽  
Søren Hvilsted
Keyword(s):  
Fuel Cell ◽  
Cell Membranes ◽  
Graft Copolymers ◽  
Side Chains ◽  
Fuel Cell Membranes ◽  
Proton Conducting

scholarly journals Electrophysiological evidence for acidic, basic, and neutral amino acid olfactory receptor sites in the catfish.

1984 ◽  
Vol 84 (3) ◽  
pp. 403-422 ◽  
Author(s):  
J Caprio ◽  
R P Byrd
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ictalurus Punctatus ◽  
Olfactory Receptor ◽  
Olfactory Receptors ◽  
Receptor Potential ◽  
Side Chains ◽  
Short Side ◽  
Neutral Amino Acids ◽  
Receptor Sites

Electrophysiological experiments indicate that olfactory receptors of the channel catfish, Ictalurus punctatus, contain different receptor sites for the acidic (A), basic (B), and neutral amino acids; further, at least two partially interacting neutral sites exist, one for the hydrophilic neutral amino acids containing short side chains (SCN), and the second for the hydrophobic amino acids containing long side chains (LCN). The extent of cross-adaptation was determined by comparing the electro-olfactogram (EOG) responses to 20 "test" amino acids during continuous bathing of the olfactory mucosa with water only (control) to those during each of the eight "adapting" amino acid regimes. Both the adapting and test amino acids were adjusted in concentrations to provide approximately equal response magnitudes in the unadapted state. Under all eight adapting regimes, the test EOG responses were reduced from those obtained in the unadapted state, but substantial quantitative differences resulted, depending upon the molecular structure of the adapting stimulus. Analyses of the patterns of EOG responses to the test stimuli identified and characterized the respective "transduction processes," a term used to describe membrane events initiated by a particular subset of amino acid stimuli that are intricately linked to the origin of the olfactory receptor potential. Only when the stimulus compounds interact with different transduction processes are the stimuli assumed to bind to different membrane "sites." Four relatively independent L-alpha-amino acid transduction processes (and thus at least four binding sites) identified in this report include: (a) the A process for aspartic and glutamic acids; (b) the B process for arginine and lysine; (c) the SCN process for glycine, alanine, serine, glutamine, and possibly cysteine; (d) the LCN process for methionine, ethionine, valine, norvaline, leucine, norleucine, glutamic acid-gamma-methyl ester, histidine, phenylalanine, and also possibly cysteine. The specificities of these olfactory transduction processes in the catfish are similar to those for the biochemically determined receptor sites for amino acids in other species of fishes and to amino acid transport specificities in tissues of a variety of organisms.

scholarly journals The Unique Branching Patterns of Deinococcus Glycogen Branching Enzymes Are Determined by Their N-Terminal Domains

2009 ◽  
Vol 75 (5) ◽  
pp. 1355-1362 ◽  
Author(s):  
M. Palomo ◽  
S. Kralj ◽  
M. J. E. C. van der Maarel ◽  
L. Dijkhuizen
Keyword(s):  
Deinococcus Radiodurans ◽  
Catalytic Domain ◽  
Amino Acid Sequence Similarity ◽  
Side Chains ◽  
Branching Pattern ◽  
Short Side ◽  
High Amino Acid ◽  
Branching Points ◽  
Branching Patterns ◽  
Branching Enzymes

ABSTRACT Glycogen branching enzymes (GBE) or 1,4-α-glucan branching enzymes (EC 2.4.1.18) introduce α-1,6 branching points in α-glucans, e.g., glycogen. To identify structural features in GBEs that determine their branching pattern specificity, the Deinococcus geothermalis and Deinococcus radiodurans GBE (GBEDg and GBEDr, respectively) were characterized. Compared to other GBEs described to date, these Deinococcus GBEs display unique branching patterns, both transferring relatively short side chains. In spite of their high amino acid sequence similarity (88%) the D. geothermalis enzyme had highest activity on amylose while the D. radiodurans enzyme preferred amylopectin. The side chain distributions of the products were clearly different: GBEDg transferred a larger number of smaller side chains; specifically, DP5 chains corresponded to 10% of the total amount of transferred chains, versus 6.5% for GBEDr. GH13-type GBEs are composed of a central (β/α) barrel catalytic domain and an N-terminal and a C-terminal domain. Characterization of hybrid Deinococcus GBEs revealed that the N2 modules of the N domains largely determined substrate specificity and the product branching pattern. The N2 module has recently been annotated as a carbohydrate binding module (CBM48). It appears likely that the distance between the sugar binding subsites in the active site and the CBM48 subdomain determines the average lengths of side chains transferred.

Facile Approach to Perylenemonoimide with Short Side Chains for Nonfullerene Solar Cells

2017 ◽  
Vol 82 (11) ◽  
pp. 5926-5931 ◽  
Author(s):  
Yu Hu ◽  
Shixiao Chen ◽  
Lifu Zhang ◽  
Youdi Zhang ◽  
Zhongyi Yuan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Side Chains ◽  
Short Side

scholarly journals Incorporation of bisphosphonates into adenine nucleotides by amoebae of the cellular slime mould Dictyostelium discoideum

1994 ◽  
Vol 303 (1) ◽  
pp. 303-311 ◽  
Author(s):  
M J Rogers ◽  
X Ji ◽  
R G G Russell ◽  
G M Blackburn ◽  
M P Williamson ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Dictyostelium Discoideum ◽  
Adenine Nucleotides ◽  
Side Chains ◽  
Short Side ◽  
Slime Mould ◽  
Trna Synthetases ◽  
Aminoacyl Trna Synthetases ◽  
Antiresorptive Agents

Bisphosphonates are a class of synthetic pyrophosphate analogues. Some are known to be potent inhibitors of osteoclast-mediated bone resorption in vivo, but their mechanisms of action are unclear. The order of potency of bisphosphonates as inhibitors of bone resorption closely matches the order of potency as inhibitors of growth of amoebae of the slime mould Dictyostelium discoideum, indicating that bisphosphonates may have a mechanism of action that is similar in both osteoclasts and Dictyostelium. Methylenebisphosphonate and several halogenated derivatives, which have low potency as antiresorptive agents and as growth inhibitors of Dictyostelium, are metabolized intracellularly by Dictyostelium amoebae into methylene-containing adenine nucleotides. We have used a combination of n.m.r. and f.p.l.c. analysis to determine whether incorporation into nucleotides is a feature of other bisphosphonates, especially those that are potent antiresorptive agents. Only bisphosphonates with short side chains or of low potency are incorporated into adenine nucleotides, whereas those with long side chains or of high potency are not metabolized. Bisphosphonate metabolism in cell-free extracts of Dictyostelium was accompanied by inhibition of aminoacylation of tRNA by several aminoacyl-tRNA synthetases. These enzymes were barely affected by the bisphosphonates that were not metabolized. The results indicate that some bisphosphonates are not metabolically inert analogues of pyrophosphate and appear to be metabolized by aminoacyl-tRNA synthetases. The cellular effects of some bisphosphonates may be the result of their incorporation into adenine nucleotides or inhibition of aminoacyl-tRNA synthetases, although the potent bisphosphonates appear to act by a different mechanism.

Proton Conducting Polysulfone Ionomers Carrying Sulfoaryloxybenzoyl Side Chains

2005 ◽  
Vol 26 (18) ◽  
pp. 1464-1468 ◽  
Author(s):  
Benoît Lafitte ◽  
Mario Puchner ◽  
Patric Jannasch
Keyword(s):  
Side Chains ◽  
Proton Conducting
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