Comparison of Aromatic Dithiophosphinic and Phosphinic Acid Derivatives for Minor Actinide Extraction

2008 ◽  
Vol 1104 ◽  
Author(s):  
Mason K. Harrup ◽  
Dean R. Peterman ◽  
Mitchell R. Greenhalgh ◽  
Thomas A. Luther ◽  
John Klaehn

AbstractA new extractant for the separation of actinide(III) and lanthanide(III), bis(o-trifluoromethylphenyl)phosphinic acid (O-PA) was synthesized. The synthetic route employed mirrors one that was employed to produce the sulfur containing analog bis(o-trifluoromethylphenyl)dithiophosphinic acid (S-PA). Multinuclear NMR spectroscopy was used for elementary characterization of the new O-PA derivative. This new O-PA extractant was used to perform Am(III)/Eu(III) separations and the results were directly compared to those obtained in identical separation experiments using S-PA, an extractant that is known to exhibit separation factors of ∼100,000 at low pH. The separations data are presented and discussed in terms comparing the nature of the oxygen atom as a donor to that of the sulfur atom in extractants that are otherwise identical.

2018 ◽  
Vol 39 (4) ◽  
pp. 474-482
Author(s):  
Hoang Thi Le Thuong ◽  
Nguyen Quang Hao ◽  
Tran Thi Thuy

Eight yeast strains (denoted as D1 to D8) were isolated from samples of natural fermented pineapple. Strain D8 showed highest alcoholic production at low pH and special aroma of pineapple has been chosen for further study. Taxonomic characterization of strain D8 using morphological, biochemical and molecular biological studies confirmed that strain D8  belong to Saccharomycetaceae family, Saccharomycetales order and Saccharomyces cerevisiae species. Therefore, we named this strain as Saccharomyces cerevisiae D8 for further study on Brandy production from pineapple. Citation: Hoang Thi Le Thuong, Nguyen Quang Hao, Tran Thi Thuy, 2017. Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple. Tap chi Sinh hoc, 39(4): 474- 482. DOI: 10.15625/0866-7160/v39n4.10864.*Corresponding author: [email protected] Received 5 December 2016, accepted 12 August 2017


2005 ◽  
Vol 388 (1) ◽  
pp. 343-353 ◽  
Author(s):  
James M. SALHANY ◽  
Karen S. CORDES ◽  
Renee L. SLOAN

Band 3 mediates both electroneutral AE (anion exchange) and APCT (anion/proton co-transport). Protons activate APCT and inhibit AE with the same pK (∼5.0). SDs (stilbenedisulphonates) bind to a primary, high-affinity site on band 3 and inhibit both AE and APCT functions. In this study, we present fluorescence and kinetic evidence showing that lowering the pH activates a second site on band 3, which binds DBDS (4,4′-dibenzamido-2,2′-stilbenedisulphonate) independently of chloride concentration, and that DBDS binding to the second site inhibits the APCT function of band 3. Activation of the second site correlated with loss of chloride binding to the transport site, thus explaining the lack of competition. The kinetics of DBDS binding at the second site could be simulated by a slow-transition, two-state exclusive binding mechanism (R0↔T0+D↔TD↔RD, where D represents DBDS, R0 and T0 represent alternate conformational states at the second DBDS-binding site, and TD and RD are the same two states with ligand DBDS bound), with a calculated overall Kd of 3.9 μM and a T0+D↔TD dissociation constant of 55 nM. DBDS binding to the primary SD site inhibited approx. 94% of the proton transport at low pH (KI=68.5±11.8 nM). DBDS binding to the second site inhibited approx. 68% of the proton transport (KI=7.27±1.27 μM) in a band 3 construct with all primary SD sites blocked through selective cross-linking by bis(sulphosuccinimidyl)suberate. DBDS inhibition of proton transport at the second site could be simulated quantitatively within the context of the slow-transition, two-state exclusive binding mechanism. We conclude that band 3 contains two DBDS-binding sites that can be occupied simultaneously at low pH. The binding kinetic and transport inhibition characteristics of DBDS interaction with the second site suggest that it may be located within a gated access channel leading to the transport site.


Beverages ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Ana Naranjo ◽  
Leticia Martínez-Lapuente ◽  
Belén Ayestarán ◽  
Zenaida Guadalupe ◽  
Irene Pérez ◽  
...  

Vitis vinífera L. cv. Maturana Blanca is an autochthonous minor variety recently recovered in the Rioja Qualified Denomination of Origin (D.O.Ca Rioja, Spain) for the production of monovarietal white wines with singular and differentiated characteristics. In this paper, Maturana Blanca wines made with different technologies were analyzed by sensory analysis and aromatic profile by gas chromatography-mass detector. Maturana Blanca wines were characterized by low pH, high acidity, and yellowish tonalities. The compounds that most influenced the aroma of Maturana Blanca wines were those related to fruity (acetates and ethyl esters), floral aromas (2-phenylethanol), and spicy notes (γ-decalactone). These wines were mainly characterized by volatile compounds of fruity aromas of banana and apple. The use of pre-fermentative maceration increased the concentration of ethyl esters and acetates and produced wines with higher odor activity values, indicating a greater aromatic intensity. The aromatic profile of Maturana Blanca wines fermented in oak barrels showed a greater complexity as they were also characterized by the presence of important amounts of furfural, whiskey lactone, and eugenol. The sensory analysis confirmed the results obtained in the aromatic analysis, and described the wines as fresh and balanced in mouth, with notes of acidity and medium to high persistence. These results will contribute to a better knowledge of this white variety.


2009 ◽  
Vol 83 (7) ◽  
pp. 3228-3237 ◽  
Author(s):  
François-Loic Cosset ◽  
Philippe Marianneau ◽  
Geraldine Verney ◽  
Fabrice Gallais ◽  
Noel Tordo ◽  
...  

ABSTRACT The cell entry and humoral immune response of the human pathogen Lassa virus (LV), a biosafety level 4 (BSL4) Old World arenavirus, are not well characterized. LV pseudoparticles (LVpp) are a surrogate model system that has been used to decipher factors and routes involved in LV cell entry under BSL2 conditions. Here, we describe LVpp, which are highly infectious, with titers approaching those obtained with pseudoparticles displaying G protein of vesicular stomatitis virus and their the use for the characterization of LV cell entry and neutralization. Upon cell attachment, LVpp utilize endocytic vesicles for cell entry as described for many pH-dependent viruses. However, the fusion of the LV glycoproteins is activated at unusually low pH values, with optimal fusion occurring between pH 4.5 and 3, a pH range at which fusion characteristics of viral glycoproteins have so far remained largely unexplored. Consistent with a shifted pH optimum for fusion activation, we found wild-type LV and LVpp to display a remarkable resistance to exposure to low pH. Finally, LVpp allow the fast and quantifiable detection of neutralizing antibodies in human and animal sera and will thus facilitate the study of the humoral immune response in LV infections.


2010 ◽  
Vol 83 (2) ◽  
pp. 151-156
Author(s):  
Mazin Y. Shatnawi ◽  
Samer A. Tanash ◽  
Saleem A. Al-Ahmad ◽  
Paul R. Challen ◽  
Gerald Henkel

2005 ◽  
Vol 38 (6) ◽  
pp. 2122-2130 ◽  
Author(s):  
June-Ho Jung ◽  
Tanja Kmecko ◽  
Christopher L. Claypool ◽  
Hongming Zhang ◽  
Patty Wisian-Neilson

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