Boundary control of heat transfer in a three-dimensional material: A hyperbolic model

We consider a boundary value problem modeling heat propagation in a homogeneous body in the framework of a hyperbolic heat conduction law. We construct a class of controls by temperature modes on the boundary that provide the desired body temperature at a given time.     

Atomic structure of unligated laccase from <Emphasis Type="Italic">Cerrena maxima</Emphasis> at 1.76 Å with molecular oxygen and hydrogen peroxide

The three-dimensional structure of unligated laccase from Cerrena maxima was established by X-ray diffraction at 1.76-Å resolution; R _work = 18.07%, R _free = 21.71%, rmsd of bond lengths, bond angles, and chiral angles are 0.008 Å, 1.19°, and 0.077°, respectively. The coordinate error for the refined structure estimated from the Luzzati plot is 0.195 Å. The maximum average error in the atomic coordinates is 0.047 Å. A total of 99.4% of amino-acid residues of the polypeptide chain are in the most favorable, allowable, and accessible regions of the Ramachandran plot. The three-dimensional structures of the complexes of laccase from C. maxima with molecular oxygen and hydrogen peroxide were determined by the molecular simulation. These data provide insight into the structural aspect of the mechanism of the enzymatic cycle. The structure factors and the refined atomic coordinates were deposited in the Protein Data Bank (PDB-ID code is 3DIV).     

Determination of antimony and tin in tin dioxide whiskers by inductively coupled plasma mass spectrometry

A procedure for the determination of antimony and tin in tin dioxide whiskers, which were grown from a gas phase by the vapor-liquid-solid mechanism, was developed. The problem was difficult because the single whiskers are irregularly small in size and have a small weight (about 10^?5 g). The procedure is based on the decomposition of a solid sample by cementation on zinc followed by the determination of analytes with the use of inductively coupled plasma mass spectrometry. The procedure developed is characterized by the detection limits of antimony of 0.01–0.03 μg/L and an RSD of 10%. An approach was proposed to estimate the antimony content of single whiskers.     

Nature of low-energy excitations in La<Subscript>1.87</Subscript>Sr<Subscript>0.13</Subscript>CuO<Subscript>4</Subscript> superconducting cuprate

The spectra of the conductivity and dielectric constant of La_1.87Sr_0.13CuO₄ cuprate have been directly measured in the frequency range of 0.3 to 1.2 THz (10–40 cm⁻¹) and the temperature range of 5 to 300 K in the E | c polarization (the electric field vector of radiation is perpendicular to the copper-oxygen planes). Excitation has been observed in the superconducting phase, and its nature has been attributed to the transverse optical excitation of the condensate of Cooper pairs, which appears because Josephson junctions between CuO planes are modulated due to in-plane magnetic and charge stripes. Additional quasiparticle absorption of unknown origin has been detected at frequencies below ≈15 cm⁻¹ at liquid helium temperatures.     

Electrochemical Decomposition of Phenylhydrazine on a Fibrous Carbon Electrode

Oxidation of phenylhydrazine by atmospheric oxygen in aqueous solution, its catalytic breakdown in the presence of Aktilen A carbon fiber, and electrochemical decomposition on a polarized carbon fiber were studied. Formation of various organic products of phenylhydrazine breakdown, remaining in solution after oxidation with air and catalytic decomposition on a carbon fiber, was studied by spectroscopy and chromatography. Feasibility of electrochemical decomposition on a carbon fiber for wastewater treatment to remove hydrazine derivatives was examined.     

Dynamics of Radiation Situation on the Territory of Belarus and Migration of Radionuclides in Different Types of Soils after Chernobyl Catastrophe

A vertical migration of radionuclides Cs, Sr and Pu in soils (in upper 5 cm) of Belarus is given. Influence of genetic parameters of soil for vertical migration of radionuclides is introduced. The main factor of the velocity for radionuclides migration is super humidity. A forecast of vertical migration of radionuclides is made for the year 2016.     

Effects of lipopolysaccharide-induced inflammation on expression of growth-associated genes by corticospinal neurons

Background  

Inflammation around cell bodies of primary sensory neurons and retinal ganglion cells enhances expression of neuronal growth-associated genes and stimulates axonal regeneration. We have asked if inflammation would have similar effects on corticospinal neurons, which normally show little response to spinal cord injury. Lipopolysaccharide (LPS) was applied onto the pial surface of the motor cortex of adult rats with or without concomitant injury of the corticospinal tract at C4. Inflammation around corticospinal tract cell bodies in the motor cortex was assessed by immunohistochemistry for OX42 (a microglia and macrophage marker). Expression of growth-associated genes c-jun, ATF3, SCG10 and GAP-43 was investigated by immunohistochemistry or in situ hybridisation.     

Initial postbuckling behavior of cylindrical composite shells under axisymmetric deformation

A solution is obtained that describes the postbuckling behavior of cylindrical shells in the case of axisymmetric buckling. The basis for this solution is Koiter’s asymptotic method and the nonlinear equations of the third-order Timoshenko theory of shells. It is shown that the bifurcation point in this case is a symmetrically unstable one. The effect of the initial axisymmetric deflections on the buckling loads is weaker when buckling is axisymmetric. The results obtained by Koiter’s special theory evidence this __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 4, pp. 108–118, April 2006.     

Features of bremsstrahlung from relativistic electrons in solid targets

It has been shown that the classical Bethe-Heitler result can be inapplicable for describing the bremsstrahlung spectrum of relativistic electrons in real solid targets.     

A preliminary X-ray diffraction study of the laccase from Coriolus zonatus in the native state

The copper-containing enzyme laccase is involved, owing to its oxidase activity, in the biodegradation of lignins—one of the most important bioconversion processes. On the basis of the X-ray diffraction data for the laccase from Coriolus zonatus, the spatial structure of this enzyme is determined with a resolution of 3.2 Å. R and R _free are 0.2347 and 0.2976, respectively, and the rms deviations of the bond lengths and the bond angles are 0.009 and 1.547 Å, respectively. The three-domain structure of the laccase from Coriolus zonatus is confirmed, where each domain is represented by a protein from the cupredoxin family. The spatial organization of the active center of the protein is established. The mononuclear center contains a copper ion Cu(1) with the atoms of S_Cys453, ND1_His395, and ND1_His458 ligands. The trinuclear center is formed by copper ions Cu(2), Cu(3), and Cu(4), surrounded by ligands of eight nitrogen atoms of the histidines of the first and third domains of the protein His66, His109, His454, His111, His400, His452, His64, and His398. The Cu(1) ion is located at distances of 11.84 and 13.22 Å from the Cu(2) and Cu(3) ions, respectively. The distance between the Cu(2) and Cu(3) ions is 5.14 Å and the Cu(4)-Cu(2) and Cu(4)-Cu(3) distances are 4.75 and 4.41 Å, respectively.