Microwave effect on the surface composition of the Urushibara Ni hydrogenation catalyst and improved reduction of acetophenone

The Urushibara Ni (U-Ni) hydrogenation catalyst and some modified forms, and for comparison Raney-Ni, were subjected to conventional (oil bath) and MW heating, and subsequently characterized by electron dispersive X-ray analysis (EDX), by BET surface area, and by scanning electron microscopy (SEM); yields of the catalyzed hydrogenation of acetophenone to 1-phenylethanol in 2-propanol by one of the modified forms (U-Ni-B) were greatly improved (from 68% to 95%).     

Design and synthesis of 4″,6″-unsaturated cyclic ADP-carbocyclic ribose as a Ca-mobilizing agent

4″,6″-Didehydro-cADPcR (3), an unsaturated carbocyclic ribose analog of a Ca²⁺-mobilizing second messenger cyclic ADP-ribose (cADPR), was designed and successfully synthesized using a key intramolecular condensation reaction forming the 18-membered pyrophosphate ring structure with a S-phenyl phosphorothioate-type substrate. Biological evaluation showed that 4″,6″-didehydro-cADPcR is a potent Ca²⁺-mobilizing agent in T cells.     

Two- and three-dimensional smectic ordering of single-handed helical polymers

Rodlike polymers with precisely defined architectures are ideal building blocks for self-assembled structures leading to novel nanometer-scale devices. We found that the living polymerization of a single isocyanide enantiomer bearing an l-alanine pendant with a long n-decyl chain simultaneously produced diastereomeric right- and left-handed helices with different molecular weights and narrow molecular weight distributions. Each single-handed, rodlike helical polymer with a controlled length and handedness isolated by a facile solvent fractionation method with acetone self-assembled to form well-defined two- and three-dimensional smectic ordering on the nanometer scale on a substrate and in a liquid crystalline state as evidenced by direct atomic force microscopic observations and X-ray diffraction measurements, respectively.     

The Cauchy problem for nonstrictly second order hyperbolic equations with nonregular coefficients

In this paper we consider the Cauchy problem for the equation , where the matrix {a _jk(x)} is non-negative, and the first derivatives of the coefficients have a singularity of orderq≥3 att=T>0; under these assumptions, the Cauchy problem is well-posed in all Gevrey classes of indexs<q/(q−1).     

New Preparation of α,β-Unsaturated Esters from 1-Alkenes Via Two Carbon Homologation Route. Synthesis of Queen Substance

2-Methylthio-4-alkenoic esters prepared from 1-alkenes and ethyl methylsulfinylacetate are converted into α,β-unsaturated esters via hydrogenation, oxidation, and thermolysis. This method was applied to the synthesis of queen substance.     

Wide-Range 2D Lattice Correlation Unveiled for Columnarly Assembled Triphenylene Hexacarboxylic Esters

Dipole bridge: Liquid-crystalline (LC) triphenylenes self-assemble columnarly into a hexagonal geometry with a wide-range 2D lattice correlation, for which distal and proximal dipole-dipole interactions are considered responsible. By virtue of the strong intercolumnar interaction, the LC columns of the triphenylene can spontaneously align homeotropically on the 12 different substrates examined (POM=polarized optical microscopy).     

On the existence in Gevrey classes of local solutions to the Cauchy problem for nonlinear hyperbolic systems with Hölder continuous coefficients

Abstract In this paper we shall solve locally in time the solutions to the Cauchy problem for first order quasilinear hyperbolic systems of which coefficients of principal part and of lower order terms are μ- H?lder and - H?lder continuous in time variable respectively and in Gevrey class of index s with respect to space variables under the assumption , where ν denotes the maximal muliplicity of characteristics of systems. Keywords: Nonlinear hyperbolic systems, Cauchy problem, Gevrey classes     

Charge transfer in CdTe at 200 and 300 K

Using a perfect single crystal sample of CdTe grown using PVT method, the electronic charge transfer in the II–VI compound semiconductor CdTe at 200 and 300 K has been evaluated using two different approaches: (1) by solving a quadratic equation involving the observed structure factors of h+k+l=4n+2 type reflections; and (2) by a graphical approach in which the observed and calculated atomic form factors are extrapolated to sinθ/λ=0, to determine the transferred charge. Precise X-ray structure factors collected using MoK radiation have been used for the analysis. The results obtained are reasonable and clearly indicate the ionicity by which charge is transferred from Cd to Te in CdTe.