Homolytic reactive mass spectrometry of fullerenes: peculiarities of the reactions of C60 with aromatic compounds in the ionization chambers of mass spectrometers and in solution.

C60 reacted with PhH, PhCl, BnH, BnNH2, and o-C2H2B10H10 in the electron impact (EI) ion source of a mass spectrometer at 300 °C forming phenyl, benzyl, and o-carboranyl adducts, respectively, stabilized by hydrogen addition and loss. Besides, the additions to C60 of methyl and phenyl radicals for toluene, and a phenyl radical for benzylamine were observed. A homolytic reaction mechanism was suggested involving the reaction of the radicals formed from the aromatics under EI with C60 at the ionization chamber walls.

Homolytic reactive mass spectrometry of fullerenes: interaction of C60 and C70 with ketones in the electron impact ion source of a mass spectrometer and the comparison of results with those of photochemical reactions of C60 with several ketones in solution.

Our previous investigations showed that homolytic reactions of C(60) with a number of perfluoroorganic and organomercury(II) compounds occurring under electron impact (EI) in the ionization chamber (IC) of a mass spectrometer could predict the reactivity of C(60) towards these compounds in solution or solid state. To expand the scope of this statement, C(60) and C(70) have been reacted with ketones RCOR(1), where R and R(1) are alkyl, aryl, benzyl, and CF(3), in an IC under EI to yield products of the addition of R(·) and R(1)(·) radicals to the fullerenes, paramagnetic ones being stabilized by hydrogen addition and loss. Experimental evidence in support of a mechanism involving homolytic dissociation of ketone molecules via superexcited states to afford these radicals that react with the fullerenes at the IC surface has been obtained.

[Mass spectrum and uniformity of decomposition of certain 2-substituted 9-(o-chlorbenzyl)-8-azahypoxanthines].

The regularities of mass spectrometric fragmentation under electron impact of new 9-(o-chlorobenzyl)-8-azahypoxantines with (N-aryl)amidocarbonylmethylthiomethyl substituents in position 2 were studied. The main fragmentation pathways are the elimination of Ar-NH+ and o-chlorobenzyl ions and cleavage of C-S bonds, characteristic of organic sulfides. During the fragmentations, some rearrangements occur, consisting in the transfer of labile hydrogen atoms from the alpha-positions to ions being eliminated.

[Method of minimally invasive gastrostomy].

An original variant of minimally invasive gastrostomy is described which is recommended for use in cases of a necessary temporary exclusion of the esophagus passage in patients with lesions of the esophagus in combination with a severe concomitant pathology.

[Experience of surgical treatment of the patients with post-burn cicatricial gastric stenosis].

Experience of surgical treatment of 48 patients with postburn cicatricial gastric stenosis was presented. In 28 of them the combined gastric and esophageal stricture were reveal. Gastric resection according to Billroth-I was performed in 26 patients, gastroduodenostomy according to Finney--in 4, gastric resection according to Hoffmeister-Finsterer--in 5, gastroenterostomy according to Belfler-Brown--in 10 and other operations--in 3.