scholarly journals PGM-Free ORR Catalysts Designed by Templating PANI-Type Polymers Containing Functional Groups with High Affinity to Iron

2019 ◽  
Vol 166 (7) ◽  
pp. F3240-F3245 ◽  
Author(s):  
Xi Yin ◽  
Hoon T. Chung ◽  
Ulises Martinez ◽  
Ling Lin ◽  
Kateryna Artyushkova ◽  
...  
Keyword(s):  
Functional Groups ◽  
High Affinity

Involvement of nitrogen functional groups in high-affinity copper binding in tomato and wheat root apoplasts: spectroscopic and thermodynamic evidence

Metallomics ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 366-376 ◽  
Author(s):  
Stéphanie Guigues ◽  
Matthieu N. Bravin ◽  
Cédric Garnier ◽  
Armand Masion ◽  
Claire Chevassus-Rosset ◽  
...  
Keyword(s):  
Functional Groups ◽  
Local Environment ◽  
Wheat Root ◽  
Copper Binding ◽  
High Affinity

A dual local environment of Cu in root apoplasts was identified.

scholarly journals Agarose Hydrogels Enriched by Humic Acids as the Complexation Agent

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 687 ◽  
Author(s):  
Martina Klučáková
Keyword(s):  
Methylene Blue ◽  
Humic Substances ◽  
Functional Groups ◽  
Humic Acids ◽  
Diffusion Coefficients ◽  
Rhodamine 6G ◽  
Effective Diffusion ◽  
High Affinity ◽  
Effective Diffusion Coefficients ◽  
Complexation Agent

The transport properties of agarose hydrogels enriched by humic acids were studied. Methylene blue, rhodamine 6G and Cu(II) ions were incorporated into hydrogel as diffusion probes, and then their release into water was monitored. Cu(II) ions as well as both the dyes studied in this work have high affinity to humic substances and their interactions strongly affected their diffusion in hydrogels. It was confirmed that humic acids retarded the transport of diffusion probes. Humic acids’ enrichment caused the decrease in the values of effective diffusion coefficients due to their complexation with diffusion probes. In general, the diffusion of dyes was more affected by the complexation with humic acids in comparison with Cu(II) ions. The effect of complexation was selective for the particular diffusion probe. The strongest effect was obtained for the diffusion of methylene blue. It was assumed that metal ions interacted preferentially with acidic functional groups. In contrast to Cu(II) ions, dyes can interact with acidic functional groups, and the condensed cyclic structures of the dye probes supported their interactions with the hydrophobic domains of humic substances.

Convergent functional groups. 13. High-affinity complexation of adenosine derivatives within induced binding pockets

1993 ◽  
Vol 115 (9) ◽  
pp. 3548-3557 ◽  
Author(s):  
M. Morgan Conn ◽  
Ghislain Deslongchamps ◽  
Javier de Mendoza ◽  
Julius Rebek
Keyword(s):  
Functional Groups ◽  
High Affinity ◽  
Binding Pockets ◽  
Adenosine Derivatives

Synthesis and applications of functionalized silsesquioxane polymers attached to organic and inorganic matrices

2008 ◽  
Vol 80 (7) ◽  
pp. 1593-1611 ◽  
Author(s):  
Yoshitaka Gushikem ◽  
Edilson V. Benvenutti ◽  
Yuriy V. Kholin
Keyword(s):  
Functional Groups ◽  
Metal Ion ◽  
Adsorption Process ◽  
Electrochemical Sensors ◽  
Water Soluble ◽  
Soluble Form ◽  
High Affinity ◽  
Insoluble Form ◽  
Amine Groups ◽  
Electroactive Species

Organofunctionalized silsesquioxane polymers obtained in a water-soluble form can be used to coat various substrates such as SiO2, SiO2/Al2O3, Al2O3, cellulose/Al2O3, and graphite or, when obtained in a water-insoluble form, can be used directly. These organofunctionalized silsesquioxanes can also be attached to poly(dimethylsiloxane) (PDMS) polymers. The functional groups constituted by neutral amine groups or cationic groups (pyridinium, 3- and 4-picolinium, or 1,4-diazabicyclo[2.2.2]octane (DABCO), mono- or -dicationic) have relatively high affinity for metal ion in ethanol solutions, as shown by their stability constants. Materials containing attached cationic functional groups have also been efficiently used to immobilize various electroactive species and to construct electrochemical sensors for analytical applications. This work discusses the preparation of silsesquioxane derivatives, their characterization as prepared and when dispersed on several substrates, and comments on some applications of these materials, with an emphasis on the metal adsorption process and manufacture of electrochemical sensors.

Evaluation of a porous silica-based ion-exchange medium for the production of protein fractions from rennet- and acid-whey

1985 ◽  
Vol 52 (1) ◽  
pp. 167-181 ◽  
Author(s):  
Paul J. Skudder
Keyword(s):  
Ion Exchange ◽  
Functional Groups ◽  
Porous Silica ◽  
Native Form ◽  
High Affinity ◽  
Nacl Concentration ◽  
Adsorbed Proteins ◽  
Acid Whey ◽  
Exchange Medium ◽  
Β Lactoglobulin

SUMMARYThe use of a silica-based ion-exchange medium for the recovery of protein from wheys prepared by treatment with rennet or with acid has been investigated. The protein capacity of the medium whilst maintaining an adsorption greater than 75% during the passage of rennet-and acid-whey was 0·079 and 0·053 g/g respectively. Bovine serum albumin (BSA), α-lactalbumin (α-la) and β-lactoglobulin (β-lg) adsorbed from acid-whey were mostly recovered in yields greater than 93% in an undenatured form essentially free of lactose and milk salts by elution using 0·1 M-HC1. With rennet-whey, BSA and part of the α-la were not recovered in the native form, probably because of proteolysis during elution by enzymes originating in the rennet used in the manufacture of the whey. There was, however, no effect on the recovery of native β-lg adsorbed by the medium. An unidentified proteinaceous fraction, thought to be of casein origin, was also adsorbed and recovered from rennet-whey. Fractions of the adsorbed proteins could not be obtained by eluting with a gradient increase in NaCl concentration. Nevertheless, purified β-lg was obtained by passing a large quantity of whey through the medium. This protein had a high affinity for the functional groups of the medium, to the extent that other proteins initially adsorbed were subsequently displaced. Unidentified proteinaceous material in rennet-whey also had a high affinity for the functional groups of the ion exchanger but most of this fraction could be removed by a pretreatment procedure which involved passing the whey through the medium at pH 5·0; unidentified material was selectively adsorbed at this pH. The medium could also be used to produce a fraction containing a mixture of BSA and α-la but it was not possible to separate these proteins.

Neuronal and Extraneuronal Uptake of 3H-Norepinephrine in the Heart of the Active Bat: An Electron Microscopic Radioautographic Study

1973 ◽  
Vol 31 ◽  
pp. 522-523
Author(s):  
Martin Hagopian ◽  
Michael D. Gershon ◽  
Eladio A. Nunez
Keyword(s):  
Smooth Muscle ◽  
Monoamine Oxidase ◽  
Vascular Smooth Muscle ◽  
Cardiac Muscle ◽  
Maximum Rate ◽  
External Medium ◽  
Extraneuronal Uptake ◽  
Electron Microscopic ◽  
Cardiac Tissues ◽  
High Affinity

The ability of cardiac tissues to take up norepinephrine from an external medium is well known. Two mechanisms, called Uptake and Uptake respectively by Iversen have been differentiated. Uptake is a high affinity system associated with adrenergic neuronal elements. Uptake is a low affinity system, with a higher maximum rate than that of Uptake. Uptake has been associated with extraneuronal tissues such as cardiac muscle, fibroblasts or vascular smooth muscle. At low perfusion concentrations of norepinephrine most of the amine taken up by Uptake is metabolized. In order to study the localization of sites of norepinephrine storage following its uptake in the active bat heart, tritiated norepinephrine (2.5 mCi; 0.064 mg) was given intravenously to 2 bats. Monoamine oxidase had been inhibited with pheniprazine (10 mg/kg) one hour previously to decrease metabolism of norepinephrine.

Improving integration between functional groups: A case in organization change and implications for theory and practice

1971 ◽  
Author(s):  
Warren G. Bennis ◽  
Michael Beer ◽  
Gerald R. Pieters ◽  
Alan T. Hundert ◽  
Samuel H. Marcus ◽  
...  
Keyword(s):  
Functional Groups ◽  
Organization Change ◽  
Theory And Practice

Clinical Application and Results of the Assessment of Coronary Blood Flow by the Regional Precordial Xenon Residue Detection Technique

1978 ◽  
Vol 17 (04) ◽  
pp. 161-171
Author(s):  
H.-J. Engel ◽  
H. Hundeshagen ◽  
P. R. Lichtlen
Keyword(s):  
Wall Motion ◽  
High Flow ◽  
Detection Technique ◽  
Fatty Tissue ◽  
Technical Aspects ◽  
Residue Detection ◽  
High Affinity ◽  
Artery Disease ◽  
The Right ◽  
Drug Interventions

Methodological and technical aspects as well as application and results of the precordial Xenon-residue-detection technique are critically reviewed. The results concern mainly normal flow in various regions of the heart esp. in the free wall of the right and left ventricle, poststenotic flow in patients with coronary artery disease in relation to the degree of proximal nar-rowings as well as wall motion of the corresponding LV segment, bypassgraft flow and flow after drug interventions esp. nitrates, betablockers, the calcium-antagonist Nifedipine and the coronary dilator Dipyridamole. In spite of its serious limitations (high affinity of Xenon for fatty tissue, geometrical problems in the assessment of flow and its relation to anatomy, gas exchange in situations of high flow etc.), the technique is found to be a usefull investigatory tool. Due to its technical display and the related high costs routine application is, however, prohibitive.

Binding of 131I-Labeled Tissue-Type Plasminogen Activator on De-Endothelialized Lesions in Rabbits

1987 ◽  
Vol 26 (05) ◽  
pp. 224-228 ◽  
Author(s):  
Y. Isaka ◽  
H. Etani ◽  
K. Kimura ◽  
S. Yoneda ◽  
T. Kamada ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Abdominal Aorta ◽  
Half Life ◽  
Balloon Catheter ◽  
Biochemical Properties ◽  
Tissue Type ◽  
Fibrin Deposition ◽  
Tissue Type Plasminogen Activator ◽  
High Affinity ◽  
Type Plasminogen Activator

Tissue-type plasminogen activator (t-PA) which has a high affinity for fibrin in the clot, was labeled with 131I by the iodogen method, and its binding to de-endothelialized lesions in the rabbit was measured to assess the detectability of thrombi. The de-endothelialized lesion was induced in the abdominal aorta with a Fogarty 4F balloon catheter. Two hours after the de-endothelialization, 131I-labeled t-PA (125 ± 46 μCi) was injected intravenously. The initial half-life of the agent in blood (n = 12) was 2.9 ± 0.4 min. The degree of binding of 131I-labeled t-PA to the de-endothelialized lesion was evaluated at 15 min (n = 6) or at 30 min (n = 6) after injection of the agent. In spite of the retention of the biochemical properties of 131I-labeled t-PA and the presence of fibrin deposition at the de-endothelialized lesion, the binding of t-PA to the lesion was not sufficiently strong. Lesion-to-control ratios (cpm/g/cpm/g) were 1.65 ± 0.40 (at 15 min) and 1.39 ± 1.31 (at 30 min), and lesion-to-blood ratios were 1.39 ± 0.32 (at 15 min) and 1.36 ± 0.23 (at 30 min). These results suggest that radiolabeled t-PA may be inappropriate as a radiopharmaceutical for the scintigraphic detection of a pre-existing thrombotic lesion.

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