RADIATION-INDUCED EXCHANGE OF DEUTERIUM BETWEEN HEAVY WATER AND DISSOLVED HYDROGEN

1957 ◽  
Vol 35 (1) ◽  
pp. 84-90 ◽  
Author(s):  
J. Bardwell ◽  
P. J. Dyne
Keyword(s):  
Heavy Water ◽  
Gamma Rays ◽  
Molecular Hydrogen ◽  
Room Temperature ◽  
Reaction Rate ◽  
Deuterium Oxide ◽  
Hydrogen Gas ◽  
Radiation Induced ◽  
Dissolved Hydrogen ◽  
Moderate Range

Exchange of deuterium between deuterium oxide and molecular hydrogen is induced by gamma rays from Co60. The reaction was studied by irradiating heavy water solutions saturated with hydrogen gas, and then analyzing the gas with a mass spectrometer. The reaction rate conforms to the exponential exchange law. The exchange yield is independent of dose rate and of hydrogen concentration over a moderate range. Prolonged irradiation leads to a steady state where the isotopic composition of the gas is close to that of the solution. This state differs greatly from that for thermodynamic equilibrium at room temperature.

scholarly journals Three- and Four-Site Models for Heavy Water: SPC/E-HW, TIP3P-HW, and TIP4P/2005-HW

2021 ◽  
Author(s):  
Johanna-Barbara Linse ◽  
Jochen S. Hub
Keyword(s):  
Molecular Dynamics ◽  
Heavy Water ◽  
Room Temperature ◽  
Deuterium Oxide ◽  
Water Structure ◽  
Light Water ◽  
Pair Potentials ◽  
Effective Pair ◽  
Water Models ◽  
Dynamics Simulations

Heavy water or deuterium oxide, D<sub>2</sub>O, is used as solvent in various biophysical and chemical experiments. To model such experiments with molecular dynamics simulations, effective pair potentials for heavy water are required that reproduce the well-known physicochemical differences relative to light water. We present three effective pair potentials for heavy water, denoted SPC/E-HW, TIP3P-HW, and TIP4P/2005-HW. The models were parametrized by modifying widely used three- and four-site models for light water, with aim of maintaining the specific characteristics of the light water models. At room temperature, the SPC/E-HW and TIP3P-HW capture the modulations relative to light water of the mass and electron densities, heat of vaporization, diffusion coefficient, and water structure. TIP4P/2005-HW captures in addition the density of heavy water over a wide temperature range.

scholarly journals Three- and Four-Site Models for Heavy Water: SPC/E-HW, TIP3P-HW, and TIP4P/2005-HW

2021 ◽  
Author(s):  
Johanna-Barbara Linse ◽  
Jochen S. Hub
Keyword(s):  
Molecular Dynamics ◽  
Heavy Water ◽  
Room Temperature ◽  
Deuterium Oxide ◽  
Water Structure ◽  
Light Water ◽  
Pair Potentials ◽  
Effective Pair ◽  
Water Models ◽  
Dynamics Simulations

Heavy water or deuterium oxide, D<sub>2</sub>O, is used as solvent in various biophysical and chemical experiments. To model such experiments with molecular dynamics simulations, effective pair potentials for heavy water are required that reproduce the well-known physicochemical differences relative to light water. We present three effective pair potentials for heavy water, denoted SPC/E-HW, TIP3P-HW, and TIP4P/2005-HW. The models were parametrized by modifying widely used three- and four-site models for light water, with aim of maintaining the specific characteristics of the light water models. At room temperature, the SPC/E-HW and TIP3P-HW capture the modulations relative to light water of the mass and electron densities, heat of vaporization, diffusion coefficient, and water structure. TIP4P/2005-HW captures in addition the density of heavy water over a wide temperature range.

scholarly journals Radiation-induced molecular hydrogen gas generation in the presence of aluminum alloy 1100

2020 ◽  
Vol 177 ◽  
pp. 109117
Author(s):  
Elizabeth H. Parker-Quaife ◽  
Christopher Verst ◽  
Colt R. Heathman ◽  
Peter R. Zalupski ◽  
Gregory P. Horne
Keyword(s):  
Aluminum Alloy ◽  
Molecular Hydrogen ◽  
Hydrogen Gas ◽  
Gas Generation ◽  
Radiation Induced

Untersuchungen über den Mechanismus des Strahlenschutzes von Thiol- und Disulfidverbindungen am Modell biologischer Elementareinheiten

1966 ◽  
Vol 21 (2) ◽  
pp. 148-152 ◽  
Author(s):  
G. Hotz
Keyword(s):  
Experimental Evidence ◽  
Gamma Rays ◽  
Room Temperature ◽  
Protective Action ◽  
Protective Mechanism ◽  
Experimental Conditions ◽  
Phage Dna ◽  
Radiation Induced

The inactivation of plaque forming ability of T 1 bacteriophage by X- and 60Co-gamma-rays was used to test the protective action of different concentrations of cysteamine and cystamine in broth-suspension, in the dry state. at 300 and at 80°K respectively. Under all experimental conditions the amount of radioprotection given by the disulfide is comparable within a few percent to the protection afforded by the thiol. The protective mechanism by which both compounds act at room temperature or at 80°K is discussed emphasizing evidence in favour of the hypothesis of electron-hydrogen donation. Oxygen reduces the efficiency of this mechanism by competing with the thiol as well as with the disulfide for radiation induced radicals in the phage DNA. Experimental evidence is given for the conclusion that cystamine needs not be reduced by enzymes or radiation to show efficient radioprotection.

Hydrogen Gas Inhalation Alleviates Radiation-Induced Bone Marrow Damage in Cancer Patients

2019 ◽  
Author(s):  
Shin-ichi Hirano ◽  
Yukimasa Aoki ◽  
Ryosuke Kurokawa ◽  
Xiao-Kang Li ◽  
Naotsugu Ichimaru ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cancer Patients ◽  
Hydrogen Gas ◽  
Bone Marrow Damage ◽  
Radiation Induced ◽  
Gas Inhalation ◽  
Hydrogen Gas Inhalation

scholarly journals Molecular Hydrogen as a Potential Clinically Applicable Radioprotective Agent

2021 ◽  
Vol 22 (9) ◽  
pp. 4566
Author(s):  
Shin-ichi Hirano ◽  
Yusuke Ichikawa ◽  
Bunpei Sato ◽  
Haru Yamamoto ◽  
Yoshiyasu Takefuji ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Molecular Hydrogen ◽  
Regulation Of Gene Expression ◽  
Animal Experiments ◽  
Radiation Energy ◽  
Water Radiolysis ◽  
Low Dose Radiation ◽  
Oxidizing Power ◽  
Radiation Induced ◽  
Radioprotective Agent

Although ionizing radiation (radiation) is commonly used for medical diagnosis and cancer treatment, radiation-induced damages cannot be avoided. Such damages can be classified into direct and indirect damages, caused by the direct absorption of radiation energy into DNA and by free radicals, such as hydroxyl radicals (•OH), generated in the process of water radiolysis. More specifically, radiation damage concerns not only direct damages to DNA, but also secondary damages to non-DNA targets, because low-dose radiation damage is mainly caused by these indirect effects. Molecular hydrogen (H2) has the potential to be a radioprotective agent because it can selectively scavenge •OH, a reactive oxygen species with strong oxidizing power. Animal experiments and clinical trials have reported that H2 exhibits a highly safe radioprotective effect. This paper reviews previously reported radioprotective effects of H2 and discusses the mechanisms of H2, not only as an antioxidant, but also in intracellular responses including anti-inflammation, anti-apoptosis, and the regulation of gene expression. In doing so, we demonstrate the prospects of H2 as a novel and clinically applicable radioprotective agent.

scholarly journals Sensing mechanism of an optimized room temperature optical hydrogen gas sensor made of zinc oxide thin films

2020 ◽  
Vol 9 (5) ◽  
pp. 10624-10634
Author(s):  
Siti Nor Aliffah Mustaffa ◽  
Nurul Assikin Ariffin ◽  
Ahmed Lateef Khalaf ◽  
Mohd. Hanif Yaacob ◽  
Nizam Tamchek ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Gas Sensor ◽  
Room Temperature ◽  
Hydrogen Gas ◽  
Oxide Thin Films ◽  
Sensing Mechanism

scholarly journals Optimizing the Reaction Conditions for the Formation of Fumarate via Trans-Hydrogenation

2021 ◽  
Author(s):  
Laura Wienands ◽  
Franziska Theiß ◽  
James Eills ◽  
Lorenz Rösler ◽  
Stephan Knecht ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Equilibrium ◽  
Reaction Rate ◽  
Low Cost ◽  
Hydrogen Gas ◽  
Metabolic Imaging ◽  
Reaction Conditions ◽  
Precursor Molecule ◽  
Solution Preparation

AbstractParahydrogen-induced polarization is a hyperpolarization method for enhancing nuclear magnetic resonance signals by chemical reactions/interactions involving the para spin isomer of hydrogen gas. This method has allowed for biomolecules to be hyperpolarized to such a level that they can be used for real time in vivo metabolic imaging. One particularly promising example is fumarate, which can be rapidly and efficiently hyperpolarized at low cost by hydrogenating an acetylene dicarboxylate precursor molecule using parahydrogen. The reaction is relatively slow compared to the timescale on which the hyperpolarization relaxes back to thermal equilibrium, and an undesirable 2nd hydrogenation step can convert the fumarate into succinate. To date, the hydrogenation chemistry has not been thoroughly investigated, so previous work has been inconsistent in the chosen reaction conditions in the search for ever-higher reaction rate and yield. In this work we investigate the solution preparation protocols and the reaction conditions on the rate and yield of fumarate formation. We report conditions to reproducibly yield over 100 mM fumarate on a short timescale, and discuss aspects of the protocol that hinder the formation of fumarate or lead to irreproducible results. We also provide experimental procedures and recommendations for performing reproducible kinetics experiments in which hydrogen gas is repeatedly bubbled into an aqueous solution, overcoming challenges related to the viscosity and surface tension of the water.

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