Temperature dependences of the low-frequency internal friction and shear modulus in a bulk amorphous alloy

The logarithmic decrement and shear modulus of a bulk amorphous Zr_52.5Ti₅Cu_17.9Ni_14.6Al₁₀ alloy were studied with an inverse torsion pendulum in the range from room temperature to the crystallization temperature and in the frequency range 5–40 Hz. The activation energy spectra of reversible and irreversible structural relaxation were estimated. The results obtained are discussed in the context of a two-energy-level model.     

Synthesis of oxazolidinylphosphine chalcogenides from aminoethyl vinyl ethers

N-(2-Vinyloxyethyl)phosphinothioamides and -phosphinoselenoamides prepared by oxidative cross-coupling of 2-vinyloxyethylamine with secondary phosphine chalcogenides undergo thermal (75–100 °C) cyclization into the corresponding 3-(diorganylchalcogenophosphoryl)-2-methyl-1,3-oxazolidines in 80–90% yields.     

Time and amplitude dependences of the damping decrement and shear modulus upon irreversible structural relaxation in a Zr-Cu-Ni-Al-Ti bulk metallic glass

The time dependences of the irreversible relaxation of the damping decrement and the shear modulus of a Zr_52.5Ti₅Cu_17.9Ni_14.6Al₁₀ bulk metallic glass are investigated using an inverse torsion pendulum in the range from room temperature to ～650 K. The spectrum of activation energies of irreversible structural relaxation is evaluated from the results obtained. Analysis of the amplitude dependences of the damping decrement and the shear modulus allows the conclusion that the relaxation centers responsible for the amplitude dependence differ from those associated with the irreversible structural relaxation at temperatures below and in the vicinity of the glass transition point.     

Effect of deformation and heat treatment on the damping constant and shear modulus of a bulk Zr-Cu-Ni-Al-Ti metallic glass

The effect of deformation by rolling or quenching from temperatures close to the glass transition temperature on the damping constant and the shear modulus of preliminarily annealed bulk samples of a Zr_52.5Ti₅Cu_17.9Ni_14.6Al₁₀ metallic glass was studied. These treatments are found to result in recovery of the “irreversible” contributions to the damping constant and the shear modulus, and the deformation treatment is shown to lead to an increase in the amplitude-dependent internal friction.     

Pharmacokinetic study of original and generic levofloxacin tablets

The comparative pharmacokinetic study of the generic levofloxacin tablets (500 mg) produced at the Zakusov Institute of Pharmacology of the Russian Academy of Medical Sciences and the original levofloxacin tablets (500 mg) Tavanic produced by Sanofi Vintron Industry (France) has been performed. The limit of quantitative determination was 25 ng/mL. The pharmacokinetic parameters of the compared preparations have been calculated. The relative bioavailability of the generic drug has been determined (108.6 ± 25.6%).     

Quantitave determination of losartan and its metabolite E-3174 in rat urine

A technique for the quantitative determination of losartan and its metabolite E-3174 in biological liquids (rat urine) has been developed. The analysis was carried out using high-performance liquid chromatography coupled with fluorescence detection. The technique??s detection limit for losartan and E-3174 was equal to 2.5 ng/mL and 5 ng/mL, respectively.     

Nonlinear elastic characteristics of Zr52.5Ti5Cu17.9Ni14.6Al10 and Pd40Cu30Ni10P20 bulk metallic glasses

The influence of uniaxial compression on the propagation of sound in Zr_52.5Ti₅Cu_17.9Ni_14.6Al₁₀ and Pd₄₀Cu₃₀Ni₁₀P₂₀ bulk metallic glasses is investigated, and the third-order elastic moduli of these glasses are determined. __________ Translated from Fizika Tverdogo Tela, Vol. 47, No. 3, 2005, pp. 395–399. Original Russian Text Copyright ? 2005 by Kobelev, Kolyvanov, Khonik.     

Comparative Pharmacokinetics and Relative Bioavailability of a New Anxiolytic GML-1 in Tablet Form

Moscow University Chemistry Bulletin - An open, single, crossover, pharmacokinetic study of GML-1 (dose 50 mg/kg) in rabbits after its oral administration in tablets and alone as a substance is...     

Quantitative determination of himantane in rat blood plasma

A technique for quantitative determination of himantane in biological liquids (the blood plasma of rats) was developed. An analysis using internal standards was carried out with the employment of high-performance liquid chromatography coupled with a mass spectrometer detector. The method was validated using the indicators of linearity, accuracy, and precision. The technique’s determination limit was calculated as 2.5 ng/ml.