Phase-Transfer catalyzed alkylation of morpholine with 1,2-dichloroethane

Russian Journal of General Chemistry -     

Synthesis of Zeaxanthin Esters

Six new zexanthin esters with 4-methylbenzoic, phenylglycolic, 2-hydroxybenzoic (salicylic), and nicotinic acids, ibuprofen, and ketoprofen, as well as benzoic acid ester, have been synthesized in anhydrous medium at 40°C in the presence of biocatalysts, Amano Lipase PS and Novozyme 435.     

An oscillator based on the stimulated Cherenkov effect

A theoretical model is proposed for a Cherenkov oscillator. Analysis is performed within the theory of quantum electrodynamics. The notion of the lifetime of an electron in a cavity is introduced, and the concept of uniform filling of a cavity with an active medium is developed. A system of balance equations is written for the number of photons and densities of active electrons in a long cavity. These equations adequately describe the output power of radiation generated in the oscillator from a spontaneous emission noise produced by a dielectric medium and an electron bunch. Analytical relationships describing the output power of the oscillator below and above a threshold are derived, and numerical evaluations are carried out. The conditions under which the oscillator power rapidly increases with a decrease in the emission wavelength are determined.     

Dynamical layer decoupling in a stripe-ordered high-T(c) superconductor

In the stripe-ordered state of a strongly correlated two-dimensional electronic system, under a set of special circumstances, the superconducting condensate, like the magnetic order, can occur at a nonzero wave vector corresponding to a spatial period double that of the charge order. In this case, the Josephson coupling between near neighbor planes, especially in a crystal with the special structure of La(2-x)Ba(x)CuO(4), vanishes identically. We propose that this is the underlying cause of the dynamical decoupling of the layers recently observed in transport measurements at x = 1/8.     

Analysis of nitroxide spin label motion in a protein-protein complex using multiple frequency EPR spectroscopy

X- and W-band EPR spectra, at room and low temperatures, are reported for nitroxide spin labels attached to cysteine residues selectively introduced into two proteins, the DNase domain of colicin-E9 and its immunity protein, Im9. The dynamics of each site of attachment on the individual proteins and in the tight DNase-Im9 complex have been analysed by computer simulations of the spectra using a model of Brownian dynamics trajectories for the spin label and protein. Ordering potentials have been introduced to describe mobility of labels restricted by the protein domain. Label mobility varies with position from completely immobilised, to motionally restricted and to freely rotating. Bi-modal dynamics of the spin label have been observed for several sites. We show that W-band spectra are particularly useful for detection of anisotropy of spin label motion. On complex formation significant changes are observed in the dynamics of labels at the binding interface region. This work reveals multi-frequency EPR as a sensitive and valuable tool for detecting conformational changes in protein structure and dynamics especially in protein-protein complexes.     

Amino acid compositions of lavender,rock rose,and rosemary

Pyatiagorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 839–840, November–December, 1990.     

Laser cooling of electrons and X-ray generation in a relativistic quantum heat engine

We consider a relativistic quantum heat engine that goes through a thermodynamical cycle consisting of stages involving laser-assisted cooling of electrons and the generation of X-ray radiation. Quantum treatment of the processes makes it possible to obtain the necessary condition and the amount of work extracted from the interaction ingredients, as well as the efficiency of the heat engine. We have also found that the efficiency of the relativistic engine is less than the one for the nonrelativistic case for the same momenta. The obtained results set the limits to the cooling, as well as the intensity of X-ray radiation, in the quantum regime of the interaction of electrons with laser fields.