Synthesis, anticancer, and anti-inflammatory activity evaluation of methanesulfonamide and amidine derivatives of 3,4-diaryl-2-imino-4-thiazolines

Condensation of 3,4-diaryl-2-imino-4-thiazoli-nes 1a–j with methanesulfonyl chloride gave methanesulfonamide derivatives 2a–j. Condensation of 2-cyanopyrazine, 4-cyanopyridine, and 2-cyanopyridine with 3,4-diaryl-2- imino-4-thiazolines 1h–m in the presence of sodium methoxide afforded amidine derivatives 3a–j. Compounds 2a–j and 3a–j were screened against various human cancer cell lines (COLO-205, HEP-2, A-549, IMR-32) and their percentage growth inhibition profile determined at 1 × 10⁻⁵M. The anti-inflammatory activity of these compounds was assessed using the carrageenan-induced paw edema model. Compound 2i exhibited 34.7% anti-inflammatory activity at 50 mg/kg p.o., which is comparable to standard care drug phenyl butazone (37% activity at 50 mg/kg p.o.)     

Comment on “Integrable Chain of Electrons Interacting With Phonons,” By M. E. Zhuravlev,V. A. Ivanov,and V. V. Achkasov,JETP Lett. 63, 94 (1996)

We note that the exactly solvable electron-phonon Hamiltonian presented in that paper can be solved by a more direct route via the Lang-Firsov transformation. Pis’ma Zh. éksp. Teor. Fiz. 64, No. 12, 859–860 (25 December 1996) Published in English in the original Russian Journal. Edited by Steve Torstveit.     

Transformation of beams of dia-, para-, and ferromagnetic particles by the magnetic field of a linear current

Some possibilities of transformation and trapping of beams of small (10⁻¹–10⁻⁴ cm) dia-, para-, and ferromagnetic particles by the magnetic field of a linear, constant current are investigated. Zh. Tekh. Fiz. 67, 138–141 (August 1997)     

Hilbert Schemes, Separated Variables, and D-Branes

We explain Sklyanin's separation of variables in geometrical terms and construct it for Hitchin and Mukai integrable systems. We construct Hilbert schemes of points on T ^*Σ for Σ=C, C ^* or elliptic curve, and on C ²/Γ and show that their complex deformations are integrable systems of Calogero–Sutherland–Moser type. We present the hyperk?hler quotient constructions for Hilbert schemes of points on cotangent bundles to the higher genus curves, utilizing the results of Hurtubise, Kronheimer and Nakajima. Finally we discuss the connections to physics of D-branes and string duality. Received: 2 November 2000 / Accepted: 7 May 2001     

Structural, magnetic, and electrical properties of solid solutions of the chromium telluride-manganese telluride system

The conditions for synthesis of solid solutions in the quasibinary CrTe-MnTe system are analyzed. A study is made of the effect of cation substitution on the properties of the synthesized solid solutions in measurements of magnetization, magnetic susceptibility, electrical conductivity, and the Seebeck coefficient at temperatures of 80–750 K. Fiz. Tverd. Tela (St. Petersburg) 39, 320–324 (February 1997)     

Luminosity Distance,Angular Size and Surface Brightness in Cosmological General Relativity

This paper corrects the explanation given by Oliveira and Hartnett, Found. Phys. Lett. 19(6), 519–535, 2006 for the luminosity distance in Cosmological General Relativity. The mathematical expression for the luminosity distance used in that paper is correct but the explanation in Eqs. (22) and (23) is flawed. Expressions for the angular size and surface brightness of sources are also derived. Finally some comment is made about the calculations of χ² values in that paper compared with an earlier paper, Found. Phys. 36(6), 839–861, 2006.     

Magnetic properties of the compounds R2Sc3Si4 (R=Gd, Tb, Dy, Ho, Er)

The magnetization of R₂Sc₃Si₄ compounds is measured in static magnetic fields up to 14 kOe in the temperature range 77–300 K. It is established that all compounds in the given series are paramagnetic at these temperatures. The paramagnetic Curie points are determined, and the effective magnetic moments are calculated. The measurements are performed on polycrystalline samples. Fiz. Tverd. Tela (St. Petersburg) 41, 1804–1805 (October 1999)     

Synthesis, structure, and formation mechanism of boron nitride nanotubes

The structure and mechanism of formation and growth are investigated for two forms of BN nanotubes produced by carbothermal synthesis. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 2, 145–150 (25 January 1999)     

Electrical, galvanomagnetic, and thermoelectric properties of PbSe in the void sublattice of opal

A study of transport phenomena, namely, electrical resistivity, thermopower, Hall coefficient, and magnetoresistance of p PbSe synthesized in opal voids has been carried out in the 4–300 K range. The parameters of the semiconducting material have been determined at different void filling levels. An anomalous behavior of the hole mobility associated with surface scattering from insulating opal-matrix walls has been observed. Fiz. Tverd. Tela (St. Petersburg) 40, 781–783 (April 1998)     

Detection of the structure of the wing of the Rayleigh line in ice, water, and heavy water using four-photon polarization spectroscopy

The spectral structure of the wing of the Rayleigh line in ice, ordinary water (H₂O), and heavy water (D₂O) is recorded in the frequency range 0–50 cm⁻¹ by means of four-photon polarization spectroscopy. It is shown that this structure can be explained by the collective rotational motion of molecules in cells determined by the structure of hexagonal ice. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 1, 12–14 (10 January 1999)     

Effect of constant-energy surface anisotropy on the thermoelectric figure-of-merit of the n-Bi2 (Te,Se,S)3 solid solutions

A study is reported of the thermoelectric and galvanomagnetic properties of n-Bi₂Te_3−x−y Se_xSe_y solid solutions for 0.12⩽x⩽0.36 and 0.12⩽y⩽0.21 within the 80–300 K temperature region. The thermoelectric figure-of-merit Z has been found to correlate with the parameters of the many-valley energy-band model including anisotropic carrier scattering. It is shown that a decrease in the constant-energy surface anisotropy and scattering anisotropy results in a growth of Z for optimum carrier concentrations in the solid solution. Fiz. Tverd. Tela (St. Petersburg) 41, 187–192 (February 1999)     

The widths of single-particle states of anisotropic, strongly correlated electron systems in solids

The damping γ(ε) of electron states in crystals is investigated beyond the phase transition point related to a rearrangement of the Fermi surface. Attention is focused on the alteration of the standard Landau theory due to the emergence of a flat portion in the spectrum ξ(p) of single-particle excitations as a result of the rearrangement. In the limit ε →0, the width γ(ε) of the states in the region of the Brillouin zone where the dispersion of ξ(p) is of an ordinary order of magnitude is found to depend on ε almost linearly, in contrast to the Fermi-liquid-theory result γ(ε)∼ε². Pis’ma Zh. éksp. Teor. Fiz. 70, No. 11, 759–765 (10 December 1999) Published in English in the original Russian journal. Edited by Steve Torstveit.     

Induced impurity photoconductivity in crystals of Si-and Ge-sillenites

The spectral distribution of the uv-induced photoconductivity intensity and relaxation in Bi₁₂SiO₂₀ and Bi₁₂GeO₂₀ crystals both undoped and doped with Al, Ga, Cr, Cu, Mn, and V is investigated in the optical range 0.5–3.5 eV in the temperature ranges 85–95 K and 285–295 K. It is shown that in the short-wavelength region 2.2–3.5 eV it is controlled by multicenter recombination in which both “fast” and “slow” recombination participate. Fiz. Tverd. Tela (St. Petersburg) 40, 1027–1029 (June 1998)     

Spin-reorientation phase transition in the basal plane in α-Fe2O3:Ga,Dy

In hematite crystals doped with gallium and dysprosium ions a spin-reorientation phase transition induced in the basal plane by the introduction of dysprosium ions was observed in the temperature range T=15–20 K. The effect is associated with the competition between the anisotropy fields arising from the iron and rare-earth subsystems. Pis’ma Zh. éksp. Teor. Fiz. 63, No. 9, 694–697 (10 May 1996)     

Optics of excitons in systems with sharp heteroboundaries. Approximation of a strongly localized exciton wave function

Optical reflection spectra from a Ga_0.7Al_0.3As/GaAs heteroboundary are calculated using the approximation of a strongly localized exciton wave function. The calculation is based on electron Γ₆ and hole Γ₈ kp-Hamiltonians with position-dependent parameters. Fiz. Tverd. Tela (St. Petersburg) 40, 872–874 (May 1998)     

Synthesis, characterization, DNA binding and cleavage studies of mixed-ligand Cu(II) complexes of 2,6-bis(benzimidazol-2-yl)pyridine

Four novel copper(II) complexes of the composition [CuLX] where L = 2,6-bis(benzimidazole-2yl)pyridine, X = dipyridophenazine (L₁), 1,10-phenanthroline (L₂), hydroxyproline (L₃) and 2,6-pyridine dicarboxylic acid (L₄) were synthesized and characterized by using elemental analysis, FT-IR, UV–vis, ESI-MS, molar conductance and magnetic susceptibility measurements. The complexes [CuLL₁](NO₃)₂ [1], [CuLL₂](NO₃)₂ [2], [CuLL₃](NO₃) [3] and [CuLL₄] (NO₃) [4] are stable at room temperature. In DMSO the complexes [1] and [2] are 1:2 electrolytes, [3] and [4] are 1:1 electrolytes. Based on elemental and spectral studies five coordinated geometry is assigned to all the four complexes. The interaction of four copper ion complexes with calf thymus DNA were carried out by UV–vis titrations, fluorescence spectroscopy, thermal melting and viscosity measurements .The binding constant (K_b) of the above four metal complexes were determined as 5.43 × 10⁴ M_,⁻¹ 2.56 × 10⁴ M⁻¹, 1.21 × 10⁴ M⁻¹ and 1.57 × 10⁴ M⁻¹ respectively. Quenching studies of the four complexes indicates that these complexes strongly bind to DNA, out of all complex 1 is binding more strongly. Viscosity measurements indicate the binding mode of complexes with CT DNA by intercalation through groove. Thermal melting studies also support intercalative binding. The nuclease activity of the above metal complexes shows that 1, 2 and 3 complexes cleave DNA through redox chemistry.     

Ranges of low-energy heavy ions in beryllium, boron, carbon, and silicon

Based on a theory of the passage of low-energy, heavy ions through matter, simple analytical expressions are obtained for calculating the average projected ranges of the ions and the rms deviations of the projected ranges. The theoretical and experimental ranges of heavy ions with atomic numbers 29⩽Z ₁⩽83 in targets of Be, B, C, and Si are compared. The theory is found to be in good agreement with experiment. Zh. Tekh. Fiz. 68, 33–36 (September 1998)     

Fluorescence of N,N-di(2-carboxyethyl)-<Emphasis Type="Italic">p</Emphasis>-anisidine in solution and crystalline states

The fluorescence properties of N,N-di(2-carboxyethyl)-p-anisidine (I) in solvents of various nature and in the crystalline state have been studied at room temperature (273 K) and at the boiling point of liquid nitrogen (77 K). Fluorescence in aqueous solutions of I with protonated (λ _ex /λ _fl ^max = 225/290 nm) and unprotonated (λ _ex /λ _fl ^max = 270/380 nm) amino nitrogen has been detected. On going from aqueous solutions to nonaqueous, the fluorescence band of unprotonated I experiences a blue shift and its intensity rises. The fluorescence intensity of the band in aprotic polar solvents is higher than that in protic solvents. A linear dependence of the fluorescence intensity of deprotonated I on Cu(II) concentration (ranging from 1.0 to 5.0 mg/dm³) in aqueous solution has been found. The fluorescence intensity of I in aqueous solutions at 77 K and pH 1–6 has been shown to increase in the presence of Zn(II) (1–170 mg/dm³) and Cd(II) (2–330 mg/dm³) although a similar dependence is not observed at 293 K.     

Investigation of the reaction D(e, pp)e′ π − on a tensorpolarized deuterium target at high proton momenta

The differential cross section of the reaction D(e,pp)e′ π ⁻ is measured in the range of proton momenta 300–720 MeV/c and proton emergence angles 64–83° for invariant masses of the pp system ranging from 2m _p to 2220 MeV/c ². The measured values of the cross section are found to differ substantially from single-particle model calculations. The components of the analyzing power for this reaction are measured. Pis’ma Zh. éksp. Teor. Fiz. 67, No. 10, 730–736 (25 May 1998) Deceased.     

Calculation of energy characteristics for Si<Subscript>1–<Emphasis Type="Italic">x</Emphasis></Subscript>Ge<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>–Si structures with single quantum wells

Energy characteristics of Si_1–x Ge _x –Si quantum-size structures with single quantum wells were calculated numerically based on a four-band k·p method. Analytical expressions for the Luttinger parameters are obtained as functions of the component composition of Si_1–x Ge _x compounds. Analytical expressions for the energy ħω of optical band-to-band transitions are obtained in an effective mass approximation and agree well with numerical calculations by the k·p method. This allows one to determine accurately a range of changes while varying the component compositions and thickness of the active and barrier layers.