Synthesis of some bis(2-morpholino-1-methylethyl) esters of carboxylic acids and study of their interaction with the cholinesterases of warm-blooded animals

The bis(2-morpholino-1-methylethyl) esters of glutaric, adipic, azelaic, and sebacic acids have been synthesized, and their dihydrochlorides and dimethiodides have been obtained. The structures of the compounds obtained have been shown by their IR and PMR spectra. The interaction of the compounds synthesized with the acetylcholineresterase (ACE) of human blood erythrocytes and the butyrylcholinesterase (BuCE) of horse blood serum have been investigated. All the bis-esters are reversible competitive inhibitors of ACE and BuCE, while the dimethiodides exhibit specificity of their action with respect to ACE.Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 239–243, March–April, 1998.     

Formation of intermediate coupling optical polarons and bipolarons in two-dimensional systems

The formation of the optical polaron and bipolaron in two-dimensional (2D) systems is studied in the intermediate electron–phonon coupling regime. The total energies of the 2D polaron and bipolaron are calculated by using the Buimistrov–Pekar method of canonical transformations. The obtained results are compared with other existing results obtained by using the Feynman path integral method and the modified Lee–Low–Pines unitary transformation method. It is shown that the electron–phonon correlation significantly reduces the total energy of the 2D polaron in comparison with the energy of the strong coupling (adiabatic) polaron. It is found that the polaron formation in 2D systems is possible when the electron–phonon coupling constant α is greater than the critical value ${\alpha }_c?2.94$, which is much lower than a critical value of the electron–phonon coupling constant α in three-dimensional (3D) systems. The critical values of the Fröhlich coupling constant α and the ratio $\eta ={\epsilon }_{\infty }/{\epsilon }_0$ (where ${\epsilon }_{\infty }$ and ${\epsilon }_0$ are the high frequency and static dielectric constants, respectively), which determine the bipolaron stability region in 2D systems, are calculated numerically. It is interesting for application to the layered cuprate superconductors that the (bi)polarons are formed more easily in quasi-2D regions than in the bulk. It is argued that the high-$T_c$ cuprate superconductivity can exist above the bulk superconducting transition temperature $T_c$ as the persisting superfluidity of polaronic (bosonic) Cooper pairs and large bipolarons at quasi-2D grain boundaries or in the CuO₂ layers above $T_c$.     

Effect of a hydrophobic interaction in the reaction of S-(β-alkylthioethyl) O-propyl methylphosphonothionates and their methyl methosulfates with cholinesterases of warm-blooded animals

The action of S-(β-alkylthioethyl) O-propyl methylphosphonates and their methyl methosulfates with different lengths of the S-alkyl radical on the enzymatic activity of acetylcholinesterase from human blood erythrocytes and butyrylcholinesterase from horse blood serum has been investigated. The existence of a hydrophobic interaction on the sorption of inhibitors in the active site of the enzymes has been established. For the enzymes investigated a definite dependence has been observed of the antienzymatic activity of the compounds on the nature in the region of the anionic point and indicates differences in their length and structure.     

Evidence for azimuthal correlations in inelastic interactions of56Fe nuclei in emulsion at 2.5A GeV/c

Azimuthal correlations in angles between various types of charged secondary particles from inelastic interactions of relativistic⁵⁶Fe nuclei with the nuclei of nuclear emulsions have been investigated. It is observed that all types of charged secondaries produced are emitted asymmetrically in the azimuthal plane. The degree of azimuthal asymmetry increases with the decrease of impact parameter. We have also observed that particles belonging to different kinematical regions of the nucleus-nucleus interaction (intergroup correlation) have a tendency to be emitted to the opposite sides in the azimuthal plane.     

Interactions of relativistic nitrogen nuclei in an emulsion at 2.1 GeV/nucleon

An analysis of multiple production induced by 2.1 GeV/n ¹⁴N ions in nuclear emulsions is presented. Multiplicity and angular distributions of charged secondaries and correlations among them are discussed. The presented data are compared with relevant values from proton-nucleus interactions. The possible appearence of collective phenomena in nucleus-nucleus interactions is discussed.     

Nuclear interactions of 21 GeV/c protons and 50 GeV/c negative pions in emulsions exposed in a strong magnetic field

Incoherent nuclear interactions of 21 GeV/c protons and 50 GeV/cπ ^?-mesons in emulsions exposed in a strong (180 kG) magnetic field have been investigated. The following topics are covered: the multiplicity of various types of charges secondaries, general features of one-particle rapidity and transverse momentum distributions, energy partitions among secondaries, characteristics of the leading particles and relativistic recoil protons, correlation relations. The experimental data are compared with predictions of current models of nuclear production.     

Interactions of 9.4 GeV/c deuterons in an emulsion: Multiplicity and angular distributions

An analysis of 1650 stars induced by 9.4 GeV/c deuterons in a nuclear emulsion is presented. Multiplicity and angular distributions of secondaries are discussed.