Enthalpies of Formation of Hydrazine and Its Derivatives.

Enthalpies of formation, ΔH, in both the gas and condensed phase, and enthalpies of sublimation or vaporization have been estimated for hydrazine, NHNH, and its 36 various derivatives using quantum chemical calculations. The composite G4 method has been used along with isodesmic reaction schemes to derive a set of self-consistent high-accuracy gas-phase enthalpies of formation. To estimate the enthalpies of sublimation and vaporization with reasonable accuracy (5-20 kJ/mol), the method of molecular electrostatic potential (MEP) has been used.

Aggregation behavior of novel heptamethine cyanine dyes upon their binding to native and fibrillar lysozyme.

Two newly synthesized symmetrical heptamethine cyanine dyes, AK7-5 and AK7-6, absorbing in the region of low autofluorescence of biological samples, have been tested for their ability to detect proteins aggregated into amyloid fibrils. In aqueous solution these probes possess three absorption bands corresponding to the monomer, dimer and H-aggregate species. The association of the dye with fibrillar lysozyme was followed by the enhancement of the monomer band and the reduction of the H-band.

Novel benzanthrone probes for membrane and protein studies.

The applicability of a series of novel benzanthrone dyes to monitoring the changes in physicochemical properties of lipid bilayer and to differentiating between the native and aggregated protein states has been evaluated. Based on the quantitative parameters of the dye-membrane and dye-protein binding derived from the fluorimetric titration data, the most prospective membrane probes and amyloid tracers have been selected from the group of examined compounds. Analysis of the red edge excitation shifts of the membrane- and amyloid-bound dyes provided information on the properties of benzanthrone binding sites within the lipid and protein matrixes.

Enthalpy of Formation and O-H Bond Dissociation Enthalpy of Phenol: Inconsistency between Theory and Experiment.

Gas-phase O–H homolytic bond dissociation enthalpy in phenol, DH298°(C6H5O–H), is still disputed, despite a large number of experimental and computational studies. In estimating this value, the experimental enthalpy of formation of phenol, ΔfH298°(C6H5OH, g) = −96.4 ± 0.

Symmetric Meso-Chloro-Substituted Pentamethine Cyanine Dyes Containing Benzothiazolyl/Benzoselenazolyl Chromophores Novel Synthetic Approach and Studies on Photophysical Properties upon Interaction with bio-Objects.

A series of symmetric pentamethine cyanine dyes derived from various N-substituted benzothiazolium/benzoselenazolium salts, and a conjugated bis-aniline derivative containing a chlorine atom at meso-position with respect to the polymethine chain, were synthesized using a novel improved synthetic approach under mild conditions at room temperature. The reaction procedure was held by grinding the starting compounds for relative short times. The novel method is reliable and highly reproducible.

Gas-phase enthalpies of formation and enthalpies of sublimation of amino acids based on isodesmic reaction calculations.

Accurate gas-phase enthalpies of formation (ΔfH298°) of 20 common α-amino acids, seven uncommon amino acids, and three small peptides were calculated by combining G4 theory calculations with an isodesmic reaction approach. The internal consistency over a set of ΔfH298°(g) values was achieved by sequential adjustment of their values through the isodesmic reactions. Four amino acids, alanine, β-alanine, sarcosine, and glycine, with reliable internally self-consistent experimental data, were chosen as the key reference compounds.

Accurate prediction of enthalpies of formation of organic azides by combining G4 theory calculations with an isodesmic reaction scheme.

Accurate gas-phase enthalpies of formation (ΔfH298°) of 29 azides are recommended by combining G4 theory calculations with an isodesmic reaction approach. The internal consistency over a set of ΔfH298° values was achieved by sequential adjustment of their values through the isodesmic reactions. The HN₃ was chosen as a key reference compound.

[Taurine. Effect on exotrophia and metabolism in mammals and fish].

Data have been presented on the taurine content in various mammalian and fish tissues as well as on pathways of its formation, turnover, and numerous functions. Based on comparison of the character of the taurine effects on various animal functions as well as of the fact of the presence of taurine in the more ancient by origin potential objects of the mammalian and fish nutrition, it is suggested that the taurine polyfunctionality has appeared at different stages of the biota.

Protective effect of taurine on rats with experimental insulin-dependent diabetes mellitus.

Taurine had the hypoglycemic effect during experimental insulin-dependent diabetes mellitus and decreased the concentrations of glucose and fructosamine, and increased the contents of insulin, C-peptide, and glycogen in the liver. Studying the dynamics of structural changes in pancreatic tissue confirmed a positive effect of taurine on beta-cell function. The protective effect of taurine manifested in the absence of morphological signs for alloxan-induced diabetes: decrease in the number and size of pancreatic islets, change in their distribution, reduction of beta-cell count, and accumulation of homogeneous deposits in islets.

[Effect of taurine and thioctacide on carbohydrate metabolism and the antioxydant system in rats with experimental diabetes].

Peroral administration of taurine and thioctacide in rats with alloxan-induced diabetes (i) decreased the levels of glucose, fructosamine and MDA, (ii) increased the levels of glycogen, insulin, and C-peptide in the liver, and (iii) increased the levels of enzymes of the antioxidant system of catalase and paraoxonase as compared to the control group of animals. These effects show that taurine and thioctacide possess hypoglycemic and antioxidant properties.

[Biotechnological synthesis of ribavirin. Effect of ribavirin and its various combinations on the reproduction of Vaccinia virus].

The biotechnological method of synthesis of ribavirin, vidarabin, and 6-azauridine by the use of immobilized recombinant enzymatic preparations of nucleoside phosphorylase was improved. The effect of ribavirin and its combinations with the other synthesized nucleosides on the reproduction of Vaccinia virus was studied using cultures of Vero cells. The combination of ribavirin and vidarabin was shown to provide an antiviral effect at lesser concentrations than when these compounds were taken separately.

[Evaluation of the capacities of neurophysiological intraoperative monitoring in reconstructive surgery on the vertebral column].

Aim: To evaluate the capacities of neurosurgical intraoperative monitoring of somatosensory evoked potentials (SSEP) in reconstructive operations on the vertebral column.

Materials And Methods: The Center of Spinal Surgery examined 30 patients treated in February to July 2001. According to the diagnosis, the distribution was as follows: degenerative diseases of the vertebral column (80%), its tumors (10%), injury (7%), and inflammatory diseases (3%).