Microencapsulation of liquid and solid substances by reactive polymers.

This study is devoted to the development of techniques for the formation of polymeric microcapsules (MC) with either liquid or solid core and with the polymer shell containing diverse functional groups on the basis of new reactive functional copolymers (FC). Two approaches to the formation of MC containing FC shell that included the stages of "oil-in-water" or "water-in-oil" dispersion preparation followed by slow extraction of solvents from dispersed phase by dispersive media were examined. FC with the same structure was successfully applied for both "oil-in-water" and "water-in-oil" systems. Spherical MC with the liquid hydrocarbon core demonstrated essential increase in their volume after heating at the temperature exceeding a boiling point of hydrocarbon encapsulated. Presence of reactive groups in the MC shell opens up new opportunity for further tuning the MC properties via their interaction with proper compounds, particularly via graft-polymerisation of diverse vinyl monomers initiated from the MC surface.

[Early diagnosis and surgical tactics at acute destructive pancreatitis].

Based on retrospective analysis of 292 case histories of patients with acute pancreatitis the computed model permitted to differentiate destructive and hydropic pancreatitis and to predict clinical course of pancreonecrosis has been constructed. Algorithm of treatment tactics depending on this analysis has been developed. Use of laparoscopy in early period with results of computed prognosis permitted to decrease the rate of diagnostic mistakes at pancreonecrosis from 59.2 to 39.5%. Algorithm of surgical tactics permitted to reduce lethality at small- and medium-focal pancreonecrosis from 51.7 to 5.1%, and the rate of purulent complication--from 23.8 to 2.5%.

Design of a new invertible polymer coating on a solid surface and its effect on dispersion colloidal stability.

This article presents a new approach to building up self-adjustable invertible polymer coatings at solid surfaces. The approach is based on a two-step process. In the first step, the surface of dispersed TiO2 or silicon wafers was functionalized with the aid of a reactive copolymer, viz., poly(styrene-alt-maleic anhydride) (PSM), to which, in the second step, the chains of amphiphilic oligoester have been tethered. The latter contains both hydrophilic poly(ethylene glycol) and hydrophobic aliphatic dibasic acid moieties being alternately distributed along the oligomer chains. It is shown that the titania modified in this way can form stable suspensions in both polar (water) and nonpolar (toluene) media. Moreover, multiple drying/redispersion cycles demonstrate the ability of the modified titania particles, after their removal from one type of dispersion and consequent drying, to be redispersed in dispersing media strongly differing by polarity from that of the previous medium. An environmentally induced switching of the surface properties has been observed via the measurement of the wetting contact angles and scanning force microscopy (SFM) of silicon wafers covered by PSM with tethered oligoester chains. These experiments give strong support for the predicted capability of such polymer coatings to switch their environmental appearance (i.e., to behave as a self-adjustable invertible interface because of the ability of the tethered amphiphilic oligoester chains to change their conformations in response to environmental changes in such a manner so as to adapt and enhance their compatibility with the surrounding media).

[The prognosis of the outcome and the correction of the treatment in bacterial meningitis by using immunological monitoring]. / Prognozirovanie iskhodov i korrektsiia lecheniia bakterial'nykh meningitov s ispol'zovaniem immunologicheskogo monitoringa.

The clinico-etiological characteristics of bacterial meningitides and cellular immunity were studied over time. Measurements were made of the phagocytic index, the phagocytic number, phagocytosis completeness, E-RFC, complementary activity of blood serum (CABS), circulating immune complexes (CIC) and IgA, IgM and IgG. The low phagocytic activity of neutrophils, phagocytosis incompleteness, the high level of CIC, a considerable reduction on CABS were associated with a grave clinical course of bacterial meningitides. In fact, they served as indicators of the necessity of instituting intensive care (hemoperfusion, plasmapheresis, ultraviolet and laser blood radiation, the use of immunomodulators). The combined administration of sodium nucleinate, levamisole and hemodez provided rapid and efficient recovery of the characteristics under study.

Possible mechanism for laser-induced two-dimensional periodic structures by analogy with the Bénard effect.

An explanation is presented for the formation of periodic structures on solid surfaces under powerful laser irradiation through an analogy to the Bénard effect.

Training of aerospace medicine physicians in the Soviet Union and the United States of America.

The Union of Soviet Socialist Republics and the United States of America operate major aerospace medicine programs; each country has taken specific measures to assure the development of an adequate number of trained aerospace medicine physicians. This jointly prepared paper emphasizes the training of aerospace medicine physicians related to civil aerospace activities. Those working in the field of aerospace medicine will find of interest the aerospace medical approaches taken by the U.S.S.R. and the U.S.A. in achieving their respective aerospace objectives.