Resolved specific dissociation channel of a core-excited peptide model molecule

In the context of the increase in chemical threat due to warfare agents, the development of efficient methods for destruction of Chemical Warfare Agents (CWAs) are of first importance both for civilian and military purposes. Amongst possible methods for destruction of CWAs, photocatalytic oxidation is an alternative one. The present paper reports on the preparation of Ta and Sn doped TiO2 photocatalysts immobilized on β-SiC foams for the elimination of diethyl sulfide (DES) used as a model molecule mimicking Yperite (Mustard Gas) in gaseous phase. Photo-oxidation efficiency of doped TiO2 catalyst has been compared with TiO2-P25. Here, we demonstrate that the Sn doped-TiO2 with a Polyethylene glycol (PEG)/TiO2 ratio of 7 exhibits the best initial activity (up to 90%) but is deactivates more quickly than Ta doped-TiO2 (40% after 800 min). The activity of the catalysts is strongly influenced by the adsorption properties of the support, as β-SiC foams adsorb DES and other sulfur compounds. This adsorption makes it possible to limit the poisoning of the catalysts and to maintain an acceptable conversion rate even after ten hours under continuous DES flow. Washing with NaOH completely regenerates the catalyst after a firs treatment and even seems to “wash” it by removing impurities initially present on the foams.

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Effects of Surface Properties and Solvent PH Values on the Adsorption/Desorption Abilities of Mesoporous SBA-15 to Methylene Blue Molecules

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.352 ◽

2012 ◽

Vol 518-523 ◽

pp. 352-355

Author(s):

Hui Liu ◽

Hong Liang Li ◽

Meng Xue Wang ◽

Jing Jing Sang ◽

Xiu Song Zhao

Keyword(s):

Aqueous Solution ◽

Methylene Blue ◽

Pore Size Distribution ◽

Pore Size ◽

Surface Properties ◽

Weak Base ◽

Adsorption Ability ◽

Ph Values ◽

Model Molecule ◽

Adsorption Desorption

Methylene blue (MB) was used as model molecule to investigate the effects of surface properties and solvent pH values on the adsorption and desorption (or release) behaviors of mesoporous SBA-15 materials. It was found that the treatment of SBA-15 with a pH 7.8 aqueous solution can enhance the adsorption rate and capacity in comparison with the pristine SBA-15. The effect of pH values on MB releasing from the weak base treated SBA-15 and the pristine one have been studied and been compared in pH values range from 0.5 to 7.0. Both of them showed a maximum releasing rate at about pH 2 and all of the treated SBA-15 samples showed a higher releasing quantity than the pristine ones. The influence mechanisms of base treatment on the adsorption ability and that of pH values on the releasing properties of SBA-15 samples have been analyzed and been discussed based on the composition, the morphology, the surface area and pore size distribution and adsorption/desorption measurements.

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Fabrication and development of controlled release PLGA microneedles for macromolecular delivery using FITC-Dextran as model molecule

Journal of Drug Delivery Science and Technology ◽

10.1016/j.jddst.2021.102712 ◽

2021 ◽

pp. 102712

Author(s):

Apoorva Panda ◽

Purnendu K. Sharma ◽

Tess McCann ◽

Joshua Bloomekatz ◽

Michael A. Repka ◽

...

Keyword(s):

Controlled Release ◽

Model Molecule

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Change in the thermal dissociation channel of molecules subjected to a high-intensity infrared radiation field

Soviet Journal of Quantum Electronics ◽

10.1070/qe1981v011n06abeh007134 ◽

1981 ◽

Vol 11 (6) ◽

pp. 839-842

Author(s):

G A Abakumov ◽

S P Shaĭtanov

Keyword(s):

Radiation Field ◽

High Intensity ◽

Infrared Radiation ◽

Thermal Dissociation ◽

Dissociation Channel

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Influence of Water-Miscible Organic Solvent on the Activity and Stability of Silica-Coated Ru Catalysts in the Selective Hydrolytic Hydrogenation of Cellobiose into Sorbitol

Catalysts ◽

10.3390/catal10020149 ◽

2020 ◽

Vol 10 (2) ◽

pp. 149

Author(s):

Tommy Haynes ◽

Sharon Hubert ◽

Samuel Carlier ◽

Vincent Dubois ◽

Sophie Hermans

Keyword(s):

Photoelectron Spectroscopy ◽

Protective Layer ◽

Textural Properties ◽

Silica Layer ◽

Ethanolic Solution ◽

Co Catalyst ◽

Hydrolytic Hydrogenation ◽

Model Molecule ◽

Influence Of Water ◽

Silica Layers

Ruthenium nanoparticles supported on carbon black were coated by mesoporous protective silica layers (Ru/CB@SiO2) with different textural properties (SBET: 280–390 m2/g, pore diameter: 3.4–5.0 nm) and were tested in the selective hydrogenation of glucose into sorbitol. The influence of key parameters such as the protective layer pore size and the solvent nature were investigated. X-ray photoelectron spectroscopy (XPS) analyses proved that the hydrothermal stability was highly improved in ethanolic solution with low water content (silica loss: 99% in water and 32% in ethanolic solution). In this work, the strong influence of the silica layer pore sizes on the selectivity of the reaction (shifting from 4% to 68% by increasing the pores sizes from 3.4 to 5 nm) was also highlighted. Finally, by adding acidic co-catalyst (CB–SO3H), sorbitol was obtained directly through the hydrolytic hydrogenation of cellobiose (used as a model molecule of cellulose), demonstrating the high potential of the present methodology to produce active catalysts in biomass transformations.

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On the molecular modeling analyses of sodium carboxymethyl cellulose treated with acetic acid

Letters in Applied NanoBioScience ◽

10.33263/lianbs82.553557 ◽

2019 ◽

Vol 8 (2) ◽

pp. 553-557 ◽

Cited By ~ 1

Keyword(s):

Acetic Acid ◽

Band Gap ◽

Carboxymethyl Cellulose ◽

Density Functional ◽

Band Gap Energy ◽

Sodium Carboxymethyl Cellulose ◽

Functional Theory ◽

Gap Energy ◽

Model Molecule ◽

Homo Lumo

Model molecules for sodium carboxymethyl cellulose (Na-CMC) (monomer), glycerol, acetic acid and Na-CMC-glycerol-acetic acid are optimized with Density Functional Theory (DFT) at B3LYP/3-21G*. For the optimized models, total dipole moment (TDM), the highest occupied and lowest unoccupied molecular orbitals (HOMO/LUMO band gap energy), and molecular electrostatic potentials (ESP) are calculated at the same method to give an explanation for the possibility of using Na-CMC-Glycerol-acetic acid model molecule in electrochemical devices, gas sensors and batteries. As a result of the substitution of Na-CMC with glycerol, TDM increased from 7.7141 Debye to 22.4942 Debye which is approximately equal to three times that of Na-CMC. However, HOMO/LUMO band gap energy decreased from 0.9040 eV to 0.5072 eV. After the addition of acetic acid to Na-CMC-glycerol model, TDM increased to24.7270 Debye and HOMO/LUMO band gap energy decreased to 0.4939 eV. Both TDM and HOMO/LUMO band gap energy values are improved by increasing the acetic acid units, where TDM became 25.3510 Debye and HOMO/LUMO band gap energy decreased to 0.3815 eV. The results of ESP indicated that the addition of glycerol and acetic acid to Na-CMC increased the electronegativity of Na-CMC which in turn enhanced its electronic properties.

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Darwin’s molecule

Hemoglobin ◽

10.1093/oso/9780198810681.003.0009 ◽

2018 ◽

pp. 201-232

Author(s):

Jay F. Storz

Keyword(s):

Protein Function ◽

Evolutionary Biology ◽

Lessons Learned ◽

Atomic Resolution ◽

Molecular Adaptation ◽

Genetic Adaptation ◽

Biochemical Phenotype ◽

Causal Connections ◽

Model Molecule ◽

Model Protein

Chapter 9 discusses conceptual issues in protein evolution and provides a synthesis of lessons learned from studies of hemoglobin function. Using hemoglobin as a model molecule, we can exploit an unparalleled base of knowledge about structure-function relationships and we can characterize biophysical mechanisms of molecular adaptation at atomic resolution. It is therefore possible to document causal connections between genotype and biochemical phenotype at an unsurpassed level of rigor and detail. Moreover, since the oxygenation properties of hemoglobin provide a direct link between ambient O2 availability and aerobic metabolism, genetically based changes in protein function can be related to ecologically relevant aspects of organismal physiology. We therefore have a solid theoretical framework for making predictions and for interpreting observed associations between biochemical phenotype and fitness-related measures of whole-animal physiological performance. The chapter explores case studies that illustrate how experimental research on functional properties of a well-chosen model protein can be used to address some of the most conceptually expansive questions in evolutionary biology: Is genetic adaptation predictable? Why does evolution follow some pathways rather than others?

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