Regulating aspects of biosoluble and insoluble film release systems containing protein proteinase inhibitor

New types of potent aprotinin-containing medicinal polymer films are elaborated for topical applications. The higher the temperature of drying, the lower the steam absorption, the film swelling, and the velocity of aprotinin in vitro release. The presence of antimicrobials having the basic functional groups contributed to compacting the structure of the films and retention of aprotinin in them. The velocity of aprotinin release from the films is regulated by adding different polymers. Inclusion of polyvinylpirrolidone in the film resulted in acceleration and increase of aprotinin release. This was probably because of increasing the film swelling by a factor of 1.7. Additional retention of the inhibitor in films was achieved by inclusion of sodium alginate and cellulose powder capable of binding aprotinin. Soluble bioadhesive films derived from a copolymer of acrylamide,N-vinyl-pirrolidone, ethyl acrylate (M _r 30,000-600,000) and aprotinin were obtained and analyzed. Kinetics of aprotinin release from biosoluble films was studied under various conditions. The duration of aprotinin release was comparable with duration of gradual dissolution of the matrix. Bioavailability of aprotinin from soluble films was linear with time.     

Cyclization of 1-hydroxy-2-(oxoalkynyl)anthraquinones

Procedures were developed for the heterocyclization of 2-benzoylethynyl-1-hydroxy-and 1-hydroxy-2-(1-oxo-3-phenylpropynyl)anthraquinone. The regioselective preparation of 2-substituted anthra[1,2-b]pyran-4,7,12-triones was demonstrated to be possible under mild conditions.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2686–2692, December, 2004.     

New Y(La)-M-O Binary Systems (M = Ca,Sr, or Ba): Synthesis,Physicochemical Characterization,and Application As the Supports of Ruthenium Catalysts for Ammonia Synthesis

The effect of the nature of the alkaline-earth metal on the phase composition and specific surface area of new Y(La)-M-O binary oxide compositions (M = Ca, Sr, or Ba) prepared by coprecipitation was studied. These systems were found to contain mixed compounds (M₂Y₂O₅, MY₂O₄, and MLa₂O₄), which are different in thermal stability, in addition to individual La₂O₃ or Y₂O₃ phases. The Y(La)-M-O compositions calcined at 450°C were characterized by a more developed specific surface area, as compared with that of individual La₂O₃ or Y₂O₃. An increase in the calcination temperature to 650°C was accompanied by a decrease in the specific surface area of binary compositions. Catalysts prepared by supporting K₂[Ru₄(CO)₁₃] onto the Y(La)-M-O systems were active in ammonia synthesis at 250-400°C and atmospheric pressure. The most active of these catalysts, K₂[Ru₄(CO)₁₃]/Y-Ba-O, provided a higher yield of NH₃ at 250-300°C than analogous catalysts prepared with the use of well-known supports (Sibunit, CFC-1, and C/MgO).     

Unexpected ligand substitutions in the cluster core {Re6Se8}: synthesis and structure of the novel cluster compound Cs11(H3O)[Re6Se4(O)4Cl6]3.4H2O

The compound Cs11(H3O)[Re6Se4(O)4Cl6]3.4H2O containing a novel cluster core {Re6Se4(O)4} with ordered ligands, where the 4 positions of one face of a Se4(O)4 cube are occupied exclusively by Se atoms and 4 O atoms lie in the opposite face was synthesized via the interaction of solid Re6Se8Br2 with molten KOH.     

Kramers mechanism of indirect spin-spin couplings of nuclei in crystals

Nuclear spin exchange in the ionic clusters [Tl₄Cl]³⁺, situated in the cavities of cation-substituted chlorosodalite, was investigated by the²⁰³Tl and²⁰⁵Tl NMR method. It was shown that nuclear spin exchange in the ionic crystals is realized by analogy with the Kramers mechanism of indirect exchange of electron spins using the electron shells of the bridging atoms.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 74–78, March–April, 1993.     

X-ray studies of interaction between magnesium chloride and ethyl benzoate, components of the catalyst for propylene polymerization

X-ray studies of the interaction between highly dispersed magnesium dichloride and ethyl benzoate (EB) at different molar ratios EB/MgCl₂, and the effect of their grinding indicate that a new compound of MgCl₂ and EB is formed. Grinding destroys the crystal phase of the new compound, thus increasing the activity and stereospecificity of the catalyst obtained.

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() /MgCl₂, . , MgCl₂. , .

     

Formation of W and Mo disulfide structures in supported catalysts for thiophene hydrogenation to tetrahydrothiophene

Upon decreasing the average size and crystallinity of supported tungsten (molybdenum) disulfide particles, the catalyst's ability to hydrogenate thiophene to tetrahydrothiophene increases. Particle dispersity increases if thiocomplexes deposited from aqueous solutions decompose on the inert support surface.     

A study of the local structure of aluminas obtained by different methods

The local structure of aluminas obtained from hydroxides (pseudo-boehmites) synthesized by different methods is studied using the radial density distribution function,. The occupancy of the cation sites of different types (tetrahedral and octahedral, spinel and non-spinel) in the structure of the studied oxides is analyzed.     

The uniqueness of determination of the space group symmetry by means of the vibrational spectroscopy methods

Vibrational spectroscopy methods are used to solve the most fundamental crystallographic problem—determination of crystal symmetry. It is shown that if X-ray diffraction methods do not make it possible to unambiguously choose the symmetry group, it can be successfully done on the basis of joint analysis of the vibrational spectroscopy and X-ray diffraction data. Irreducible representations of vibrations for all systems are systematized, and the cases are indicated where the ambiguity in assignment of crystal structures to the space groups with unified diffraction extinction rules can be avoided.     

Chemical vapor infiltration method for deposition of gold nanoparticles on porous alumina supports

Knudsen’s effusion method with mass spectral analysis of the composition of the gas phase was used to measure the temperature dependence of the saturated vapor of several (CH₃)₂AuL chelate complexes and to determine the thermodynamic parameters of their sublimation. Based on the results of this study, conditions for chemical vapor deposition of gold using dimethylgold(III) chelates were chosen. Gold nanoparticles were synthesized by chemical vapor deposition (infiltration) of (CH₃)₂Au(acac) on porous granules of γ-Al₂O₃ with subsequent calcination in air at 325°C. Particle size and the chemical state of gold in Au/γ-Al₂O₃ systems were evaluated by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). A vapor infiltration procedure is suggested to prepare metallic gold particles ≤5 nm in diameter from Au/γ-Al₂O₃. It is shown that Au/γ-Al₂O₃ systems obtained by chemical vapor infiltration and containing small gold crystallites possess high catalytic activity in CO oxidation reactions at 40°C.