Limits on light-speed anisotropies from Compton scattering of high-energy electrons.

The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the European Synchrotron Radiation Facility's GRAAL facility constrains such anisotropies representing the first nonthreshold collision-kinematics study of Lorentz violation. When interpreted within the minimal standard-model extension, this result yields the two-sided limit of 1.6×10(-14) at 95% confidence level on a combination of the parity-violating photon and electron coefficients (κ(o+))(YZ), (κ(o+))(ZX), c(TX), and c(TY). This new constraint provides an improvement over previous bounds by 1 order of magnitude.

Simultaneous photoproduction of eta and pi0 mesons on the proton.

The analysis of the gammap-->etapi(0)p reaction has been performed using data from the GRAAL experiment. The total and differential cross sections and the beam asymmetry have been obtained from threshold up to 1.5 GeV of beam energy. The two resonances S11(1535) and Delta(1700) are expected to be excited in the intermediate states of this reaction. The results are used to test predictions based on the assumption that both resonances are dynamically generated from the meson-baryon interaction provided by chiral Lagrangians. The term involving the Delta(1700) excitation, followed by the decay into etaDelta(1232), is found to be dominant.

Evidence for nucleon-resonance excitation in omega-meson photoproduction.

The photoproduction of the omega meson has been studied at GRAAL from threshold up to a photon energy of 1.5 GeV. The differential cross sections and beam asymmetries have been measured precisely at all angles. The total cross section is also obtained. Systematic enhancements of the differential cross section at large angles and nonzero beam asymmetries at intermediate angles provide clear evidence for s- and u-channel resonant processes. The data are compared to the results of hadron and quark models.

Double pi(0) Photoproduction on the Proton at GRAAL.

The double pi(0) photoproduction off the proton has been measured in the beam energy range of 0.65-1.5 GeV. The total and differential cross sections and the Sigma beam asymmetry were extracted. The total cross section measured for the first time in the third resonance region of the nucleon shows a prominent peak. The interpretation of these results by two independent theoretical models infers mostly the selective excitation of P11- and D13-nucleon resonances.

[The antiarrhythmic activity of the polymeric forms of quinidine, trimecaine, etatsizin, propranolol and verapamil]. / Antiaritmicheskaia aktivnost' polimernykh form khinidina, trimekaina, étatsizina, propranolola i verapamila.

The antiarrhythmic activity and acute toxicity of polymeric formulations of quinidine, trimecaine, ethacizine, propranolol, verapamil which had been immobilized on a cellulose carrier (monocarboxylcellulose) and low molecular analogues were studied in various experimental animals (rats, mice, dogs). The polymeric formulations of trimecaine and verapamil were found to have a higher antiarrhythmic activity in different arrhythmia models than trimecaine and verapamil. The toxicity of all new compounds was no more than the values of conventional antiarrhythmic drugs.