Adsorption of polyvinylpyrrolidone and polyoxyethylene by pure and mixed silicon, aluminium and titanium oxides

Adsorption of polyvinylpyrrolidone (PVP) and polyoxyethylene (POE) from the aqueous solutions onto surfaces of individual and mixed silicon, titanium and aluminium oxides was studied. It was found that the values of polymer adsorption depend on composition of oxides. It was shown with IR spectroscopy that the surface of the oxides studied is fully accessible to interaction with PVP and POE

Введение лекарственных препаратов в субтеноновое пространство глаза в лечении передней ишемической нейропатии

International audienceIn spite of treatment provided in anterior ischemic neuropathy, a prognosis for visual functions is poor and depends on severity of affection of vascular system of the body. We have studied the exposure to cortexin and diprospan in subtenon administration on the eye hemodynamics in 18 patients experiencing anterior ischemic neuropathy(18 eyes) who have been treated operatively (administration of cortexin and diprospan into the subtenon space of the affected eye) against the background of complex conservative prevention. The control group was constituted of 16 patients (16 eyes) who have not been treated operatively. As a result of provided treatment the patients of the basic group showed increase of vision acuity, field of view limits and eye ground state.Незважаючи на про­ведене лікування при передній ішемічній нейропатії, прогноз для зорових функцій несприятливий та залежить від ступеня тяжкості ураження судинної системи організму. Нами вивчено вплив кортексина та дипроспана при субтеноновому введенні на гемодинаміку ока у 18 хворих на передню ішемічну нейропатію (18 очей), яким на тлі комплексного медикаментозного лікування проводилось оперативне лікування (введення кортексина та дипроспана в субтеноновий простір ураженого ока). Контрольну групу склали 16 хворих (16 очей), яким не проводилось оперативне лікування. Під впливом проведеного лікування у хворих основної групи достовірно покращилися показники гостроти зору, меж поля зору, стан очного дна

Adsorption and Migration of Poly(Vinyl Pyrrolidone) at a Fumed Silica Surface

A series of poly(vinyl pyrrolidone) (PVP)/fumed silica powder samples were studied using adsorption, FT-IR and AFM methods. Mild treatment (293 K for several hours) of PVP/A-300 powder with an added additional portion of A-300 in a glass reactor (2 dm 3 ) using a mixer (> 500 rpm which provided the powder as a pseudo-liquid state, PLS) led to the redistribution (migration) of the PVP molecules between silica particles previously covered by PVP and free of PVP. This time-dependent rearrangement of the adsorbed PVP molecules caused the formation of a denser polymer layer at the silica surface. The aggregate size of the primary silica particles with adsorbed PVP molecules decreased after treatment. The volume of macropores with a pore radius R p > 25 nm increased due to the decrease in the distances between aggregates in agglomerates because of the adhesive effect of the PVP molecules. However, the volume of micropores at R p < 1 nm decreased because of the penetration of the PVP molecules into the primary silica particle aggregates and the filling of gaps between adjacent particles. A decrease occurred in the amount of adsorbed water in the PVP layer exhibiting a maximum density