نتایج جستجو برای: hydrazine hz
تعداد نتایج: 43158 فیلتر نتایج به سال:
[1] The exhaust plume of Phoenix’s hydrazine monopropellant pulsed descent thrusters will impact the surface of Mars during its descent and landing phase in the northern polar region. Experimental and computational studies have been performed to characterize the chemical compounds in the thruster exhausts. No undecomposed hydrazine is observed above the instrument detection limit of 0.2%. Forty...
Hydrogenation of azo bonds with hydrazine, mono-substituted hydrazine, and hydrazobenzene was studied with selected diazene compounds under oxygen-free conditions. The reactions proceed rapidly and in high yield in several solvents, utilizing all N-H protons. While the reduction process is accompanied by the evolution of nitrogen gas in the case of N2H4, the intermediacy of diimide could not be...
we have performed a density functional theory investigation on the structural and electronic properties of pristine and nitrogen-doped tio2 anatase nanoparticles as the adsorbents for removal and degradation of hydrazine molecules in the environment. we have presented the most stable adsorption configurations and examined the interaction of hydrazine molecule with these doped and undoped nanopa...
In previously published studies, we had demonstrated that hydrazine sulfate pretreatment protected mice against the lethal effects of endotoxin and that this protection was accompanied by a sustained increase in hepatic phosphoenolpyruvate carboxykinase activity (Silverstein, R., C.A. Christoffersen, and D.C. Morrison. 1989. Infect. Immun. 57:2072). The same hydrazine sulfate pretreatment has n...
HD formation from either Da and Hz0 or Hz and DzO is shown to be catalyzed by Nz-fixing extracts of Azotobacter vinelandii. The activity parallels nitrogenase but not hydrogenase activity and is not catalyzed by the sites of nitrogenase responsible for either ATP-dependent Hz evolution or competitive inhibition by Hz of Nz fixation. Requirements in addition to nitrogenase are NB, ATP, and reduc...
The reaction of hydrazine with the cytosine residues of DNA yields 3-ureidopyrazole, in approximately 50% yield, in addition to the expected 3-aminopyrazole. This product has been identified by ultraviolet, infrared, nuclear magnetic resonance and mass spectroscopy. A product of the reaction of hydrazine hydrate with cytosine, formulated by others as NN'-di-(3-pyrazolyl) hydrazine, has been ide...
The reactivity of hydrazine in the presence of diborane has been investigated using ab initio quantum chemical computations (MP2 and CCSD(T) methods with the aug-cc-pVTZ basis set). Portions of the relevant potential energy surface were constructed to probe the formation mechanism of the hydrazine diborane (BH(3)BH(3)NH(2)NH(2)) and hydrazine bisborane (BH(3)NH(2)NH(2)BH(3)). The differences be...
Although the precise mechanism of endotoxin lethality has yet to be defined, it is well recognized that the amount of hepatic phosphoenolpyruvate carboxykinase is reproducibly and significantly reduced after challenge with endotoxin. Hydrazine has been shown to be a specific inhibitor of gluconeogenesis, causing a metabolic crossover at the step catalyzed by phosphoenolpyruvate carboxykinase. M...
Isoniazid is one of the most commonly used drugs to treat tuberculosis. Its administration is associated with a high incidence of hepatotoxicity. The aim of this study was to establish the protective effects of taurine against cytotoxicity induced by isoniazid and its suspected toxic metabolite hydrazine in isolated rat hepatocytes by measuring reactive oxygen species (ROS) formation, lipid per...
The title compound, poly[(μ2-hydrazine)(μ4-phosphato)iron(III)], [Fe(PO4)(N2H4)] n , was prepared under hydro-thermal conditions. Its asymmetric unit contains one Fe(III) atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The Fe(III) atom is bound to four O atoms of symmetry-related PO4 tetra-hedra a...
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