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The multifactorial nature of the retinopathy of prematurity (ROP) pathogenesis, makes the thorough study of the mechanism of pathological retinal neovascularization actual. However recently the attention of scientists has been attracted by the participation of renin-angiotensin system (RAS) in the development of retinal vasoproliferative diseases. Purpose: to study the role of AT-II in the pathogenesis of experimental ROP (EROP) in the original model of the disease. Material and methods. To reproduce EROP Wistar rats (n = 15) were exposed to the oxygen concentration varying from 60 to 15% every 12 hours for 14 days from the first day after birth followed by room air for 7 days. Throughout the experiment, the room maintained a constant temperature (+26 °C) and light regime (12 hours a day, 12 hours a night) modes. Control rats (n = 12) were born and kept under normal oxygen content (21 %). Batches of EROP (n = 5) and control (n = 4) rats were sacrificed on 7, 14 and 21 days. All rats underwent binocular enucleation, after which every eyeball was opened on the limb, the cornea and lens were removed with the remains of a persistent vascular bag and a hyaloid artery. Retinas were isolated, homogenized and stored at -20 °C. Angiotensin-II (AT-II) in homogenates was measured using the IFA kit. Results. On the 7th day of the experiment, the level of AT-II in the retina of the experimental group rats was 0.19 ± 0.02 pg/mg protein that was significantly higher than in controls (0.12 ± 0.01 pg/mg protein). On the 14th and 21st days concentrations of AT-II in EROP and control groups had no significant difference. Conclusion. On the 7th day of the experiment, i.e. at the period corresponding to the existence of avascular retinal zones in both groups concentration of AT-II in the retinas of rats with EROP was significantly higher than in controls. This fact indicate the role of this proangiogenic factor in the induction of pathological neovascularization in ROP. Possible prognostic function of this parameter during the period before ROP manifestation has undoubted practical significance.

The article provides research results and comparative analysis of humic acids in sod-podzolic soil of the Experimental Forest of the Russian State Agrarian University (protected area) and urban soils located in the Timiryazev district of Moscow. Humic acids of the zonal sod-podzolic soil of the Experimental Forest include four fractions with varying molecular weight: the 1 st fraction – ≥ 23 440 unified atomic mass units (amu), the 2 nd one – 13 340 amu, the 3 rd one – 5 500 amu and the 4 th one – 2 460 amu. The fraction with a molecular weight of 5 500 amu and a relative content of 38 % dominates among them, while the share of low-molecular fractions (< 20 000 amu) accounts for 70 % of the total mass of humic acids. When weight-average molecular mass of humic acids is 17 530 amu, the average molecular mass of the low-molecular fractions is 9 960 amu. Humic acids of urbanozems differ in molecular weight composition from humic acids of sod-podzolic soil. In most cases it consists of 5–6, less commonly of 3, fractions with molecular weight from 1 780 to ≥ 23 440 amu. The share of medium- and high-molecular fractions fluctuates from 31–37 % to 47–50 % of the total mass of humic acids. The characteristic feature of humic acids of urbanozems is the presence in their composition of low-molecular fractions with such molecular weights, which are not found in humic acids of sod-podzolic soil. Thus, humic acids of urbanozems are characterized by higher weight-average molecular mass ranging from 17 680 to 19 980 amu, as well as by higher weigh-average molecular mass of the low-molecular fractions which vary from 10 680 to 13 650 amu.

Purpose: to assess the level of catecholamines norepinephrine and dopamine in rat retina with experimental retinopathy of prematurity (EROP) at a time corresponding to the peak of neovascularization.Material and methods. The study was performed on 41 infant Wistar rats (82 eyes). The rats were divided into 2 groups: the experimental group (with EROP, n = 21) and the control group (n = 20). In order to reproduce the EROP, the newborn rats were placed for 14 days in the incubator together with their mother. Every 12 hours, the oxygen concentration in the incubator ranged from 60 to 15 %. The control group consisted of pups who were held in conditions with a normal oxygen content (21 %) from the moment of birth. The pups were withdrawn from the experiment on the 10th, 14th, 23rd and 28th day, whereupon they were subjected to binocular enucleation followed by histological examination, in addition, the content of noradrenaline and one of the metabolites of dopamine (L-DOPA) was determined in retinal samples of the eyeballs obtained on the 23rd day by highly effective liquid chromatography technique with electrochemical detection.Results. Histological examination showed that in our EROP model the neovascularization peak occurs on the 23rd day of the experiment. At this time rat pups with EROP showed a significantly lower retinal L-DOPA level as compared to the control values (13.99 ng/g and 30.5 ng/g, respectively), and the norepinephrine level significantly exceeded such values (63.7 ng/g and 7.69 ng/g, respectively).Conclusion. A relative deficiency of dopamine and a relative excess of norepinephrine of the rat pups with EROP is noted at the time of the highest vascular activity of the retina. The obtained data confirm anti-angiogenic properties of dopamine and pro-angiogenic properties of noradrenaline in the second phase of EROP development.

This study describes clinical and radiological implications as well as early surgical treatment results of a rare and late complication of a nonporous silicone orbital implant, in particular its encapsulation with the formation of an inclusion cyst.

The paper presents the results of precision measurements of the total stopping range and energy deposition function of 238U ions with specific energies E = 500 and 950 MeV/u in stainless steel and copper targets. The experiment was performed at the SIS-18 facility (GSI Darmstadt) in the experimental area Cave A in September 2004–May 2005. The measured energy deposition profiles are compared with calculations using the codes ATIMA, PHITS, SHIELD and SRIM.

The reaction conditions and component ratios were established for the attachment of 4-(2-pyridylazo)resorcinol (PAR), 1-(2-pyridylazo)-2-naphthol (PAN) and 8-hydroxyquinoline (8-HQ) to the silica surface by means of a single-stage Mannich reaction. The modified sorbents that were synthesized were characterized by an adsorption method, and DRIFT and UV spectroscopies. The concentrations of PAR, PAN and 8-HQ grafted to the silica surface that were attained were 2.8×10−5, 8.5×10−5 and 2.7×10−4 mol g−1, respectively.

Sub-millimetre wall thickness is foreseen for the vacuum tubes in the magnets of the superconducting dipoles of the SIS100 and SIS300 of the FAIR Project. The Bragg peak of the energy deposition by the U ions in these walls may lie dangerously close to the superconducting cables. Thus the precise knowledge of the dE/dx profile is essential for estimating the heat load by the lost ions in the vicinity of the superconducting wires. Here we present the preliminary results of the measurement of the U ion beam energy deposition profile in Cu and stainless steel targets and compare the measured data with the dE/dx calculations using different codes.