Non-Conjugated Copoly(Arylene Ether Ketone) for the Current-Collecting System of a Solar Cell with Indium Tin Oxide Electrode.

The mechanism of charge carrier transport in the indium tin oxide (ITO)/polymer/Cu structure is studied, where thin films of copoly(arylene ether ketone) with cardo fluorene moieties are used. This copoly(arylene ether ketone) is non-conjugated polymer which has the properties of electronic switching from the insulating to the highly conductive state. The dependence on the polymer film thickness of such parameters as the potential barrier at the ITO/polymer interface, the concentration of charge carriers, and their mobility in the polymer is studied for the first time.

(+)-Catechin Stereoisomer and Gallate Induce Oxidative Stress in Rat Aorta.

The goal of the work was to study changes in the activity of the angiotensin-converting enzyme (ACE) and production of reactive oxygen species (ROS) in the aorta of rats after the intraperitoneal injection of stereoisomers of catechin and gallate. The activity of ACE in the aorta sections was determined by measuring the hydrolysis of hippuryl-l-histidyl-l-leucine. The production of ROS in the aorta sections was estimated from the oxidation of dichlorodihydrofluorescein.

Structure-Property Relationship on the Example of Gas Separation Characteristics of Poly(Arylene Ether Ketone)s and Poly(Diphenylene Phtalide).

Three poly(arylene ether ketone)s (PAEKs) with propylidene (C1, C2) and phtalide (C3) fragments, and one phtalide-containing polyarylene (C4), were synthesized. Their chemical structures were confirmed via H NMR, C NMR and F NMR spectroscopy. The polymers have shown a high glass transition temperature (>155 °C), excellent film-forming properties, and a high free volume for this polymer type.

Black tea is more effective than green tea in prevention of radiation-induced oxidative stress in the aorta of rats.

In the work, the effect of black tea on oxidative stress induced in the aorta by irradiation was studied. The efficiency of black and green tea types was compared, and the effect of the main green tea components (-)-epigallocatechin galate (EGCG) and (-)-epigallocatechin (EGC) on the aorta was studied. The activity of ACE in rat aorta segments was determined by measuring the hydrolysis of hippuryl-L-histidyl-L-leucine, and the production of ROS was estimated from the oxidation of dichlorodihydrofluorescein.

Effects of Catechin on Activity of Angiotensin-Converting Enzyme and Generation of Reactive Oxygen Species in Rat Aorta.

Activity of angiotensin-converting enzyme (ACE) and intensity of ROS generation in the aorta were studied in male Wistar rats intraperitoneally injected with a mixture of (+) and (-) stereoisomers of catechin. ACE activity in aortal segments was evaluated by hydrolysis of hippuryl-histidine-leucine; ROS generation was measured by oxidation of dichlorodihydrofluorescein. The dynamics of ACE activity and intensity of ROS generation in the aorta after catechin administration and their dependence on the catechin dose were studied.

Radiation-Induced Transient Currents in Films of Poly(arylene ether ketone) Including Phthalide Moiety.

The electrical properties of thin films of poly(arylene ether ketone) copolymers (co-PAEKs) with a fraction of phthalide-containing units of 3, 5, and 50 mol% in the main chain were investigated by using radiation-induced conductivity (RIC) measurements. Transient current signals and current-voltage () characteristics were obtained by exposing 20 ÷ 25 μm thick films of the co-PAEKs to monoenergetic electron pulses with energy ranging from 3 to 50 keV in an electric field ranging from 5 to 40 V/μm. The Rose-Fowler-Vaisberg semi-empirical model based on a multiple trapping formalism was used for an analysis of the RIC data, and the parameters of the highly dispersive charge carrier transport were evaluated.

Blood Pressure Changes After Exposures Increasing Angiotensin-Converting Enzyme Activity and After Its Normalization with Dihydroquercetin in Male Wistar Rats.

Changes in BP and HR were assessed after exposures increasing activity of angiotensin-converting enzyme: ionizing radiation, NO synthase inhibitor (L-NAME), and dexamethasone. Effects of dihydroquercetin and angiotensin-converting enzyme inhibitor enalapril on activity of this enzyme, BP, and HR were also evaluated under these exposures. Wistar male rats were subjected to X-ray irradiation in a dose of 2.

Flavonoids decrease the radiation-induced increase in the activity of the angiotensin-converting enzyme in rat aorta.

The basic factor of cardiovascular diseases is atherosclerosis, which is due largely to an increase in the activity of the angiotensin-converting enzyme (ACE) in vessels. Flavonoids diminish the risk of cardiovascular diseases and the flavonoid taxifolin normalizes the activity of ACE. We examined the efficiency of seven flavonoids in preventing an increase in ACE activity in aorta of rats exposed to ionizing radiation.

Dihydroquercetin and Fucoidin Inhibit the Increase of Angiotensin-Converting Enzyme Activity in the Rat Aorta after Irradiation.

The time course of angiotensin-converting enzyme activity in the rat aorta after fractionated exposure to ionizing radiation and the effects of dihydroquercetin and fucoidin on this parameter were studied. Male Wistar rats were exposed to single or repeated (fractionated) X-ray radiation in a dose of 2.5 Gy at 200 kV.

Ionizing Radiation Enhances Activity of Angiotensin-Converting Enzyme in Rat Aorta.

We analyzed changes in angiotensin-converting enzyme activity in rat aorta at the early terms after irradiation in doses equal to one fraction dose used in tumor radiotherapy. Male Wistar rats were exposed to whole body or local (chest) X-ray irradiation (200 kV, 1-7.5 Gy).

Lipoxygenase Inhibitors Nordihydroguaiaretic Acid and Fungus Lecanicillum lecanii Extract Induce Death of Lymphoid Leukemia Cells.

We studied the effect of lipoxygenase inhibitors nordihydroguaiaretic acid (NDGA) and fungus Lecanicillum lecanii extract on lymphatic leukemia P388 cells. The cells grown in the abdominal cavity of DBA2 mice for 7 days were transferred into a nutrient medium. The effect of lipoxygenase inhibitors was evaluated by changes in cell number, trypan blue staining, nucleus damage, and changes in cell distribution by DNA content after 22-h incubation.

Taxifolin and Fucoidin Abolish the Irradiation-Induced Increase in the Production of Reactive Oxygen Species in Rat Aorta.

We studied changes in ROS content in the aorta of Wistar rats at early terms after irradiation in doses equal to single fraction used in tumor radiotherapy and the effects of taxifolin and fucoidin, blockers of leukocyte adhesion to endothelium, on ROS content. Male rats were exposed to X-rays (200 kW) in doses of 1-7.5 Gy.

[Screening of Organisms Producing Inhibitors of 15-Lipoxygenase Among Micromycetes.].

The effects of extracts from the mycelium of Lecanicilium lecaniiNo.169, Beauveria fellina No.7 and Beauveria bassianaNo.

[Change of Tumor Cell Multiple Drug Resistance Inhibitory Activity of Oligomycins in Complexes with Lithium and Zinc].

Oligomycins and their complexes with lithium and zinc were shown to be less active vs. cyclosporin A in inhibition of transport proteins responsible for multiple drug resistance of lymphoid leukosis P388VR cells, while certain oligomycin complexes were tens or hundreds times more active than cyclosporin A by inhibition of transport proteins in another type of tumor cells, i.e.

Camel thorn extract reduces activity of angiotensin-converting enzyme in rat aorta increased during aging and treatment with NO-synthase inhibitor.

We studied the effect of camel thorn extract on activity of angiotensin-converting enzyme in rat aorta increased in animals during aging or treatment with NO-synthase inhibitor. Intake of camel thorn extract with drinking water reduced activity of angiotensin-converting enzyme; the effect increased with increasing the dose of the extract. Angiotensin-converting enzyme activity in older rats and animals treated with NO-synthase inhibitor decreased to the values observed in young control rats at extract concentration of 0.

Effects of high-salt diet on the activity of angiotensin-converting enzyme and generation of reactive oxygen species in rat aorta.

The dynamics of angiotensin-converting enzyme activity in the aorta and blood plasma and generation of ROS in the aorta were studied in rats subjected to two high-salt diets (0.4% and 1% NaCl solutions). During high-salt diets, activity of angiotensin-converting enzyme in the aorta progressively decreased to the minimal during week 1 and remained lower than control level for 1 month.

Effects of taxifolin on the activity of angiotensin-converting enzyme and reactive oxygen and nitrogen species in the aorta of aging rats and rats treated with the nitric oxide synthase inhibitor and dexamethasone.

The action of taxifolin on the angiotensin-converting enzyme (ACE) and the formation of reactive oxygen and nitrogen species (ROS/RNS) in the aorta of aging rats and rats treated with nitric oxide synthase inhibitor (N ω-nitro-L-arginine methyl ester (L-NAME)) or dexamethasone have been studied. The ACE activity in aorta sections was determined by measuring the hydrolysis of hippuryl-L-histidyl-L-leucine, and the ROS/RNS production was measured by oxidation of dichlorodihydrofluorescein. It was shown that taxifolin at a dose of 30-100 μg/kg/day decreases the ACE activity in the aorta of aging rats and of rats treated with L-NAME or dexamethasone to the level of the ACE activity in young control rats.

Low doses of ethanol decrease the activity of the angiotensin-converting enzyme in the aorta of aging rats and rats treated with a nitric oxide synthase inhibitor and dexamethasone.

In the present study, the activity of ACE (angiotensin-converting enzyme) in the aorta of senescent rats and rats treated with the NOS (NO synthase) inhibitor L-NAME (NG-nitro-L-arginine methyl ester) or dexamethasone and the effect of low doses of ethanol (0.2-1.2 g/kg of body weight, daily for 8-12 days) on this activity were studied.

Distribution of the activity of the angiotensin-converting enzyme in the rat aorta and changes in the activity with aging and by the action of L-NAME.

The activity of the angiotensin-converting enzyme (ACE) of the inner surface (the endothelium surface) of rat aorta sections has been studied depending on their distance from the aortic arch, age of rats, and the duration of treatment of rats with the NO synthase inhibitor, N (ω)-nitro-L-arginine (L-NAME). The activity of ACE of aorta sections was determined by measuring the hydrolysis of hippuryl-L-histidyl-L-leucine and was expressed as picomoles of Hip-His-Leu hydrolyzed per minute per square millimeter of the endothelium surface. It was found that the ACE activity considerably varies along the aorta of young rats.

[Multidrug resistance increase of tumor cells at the effect of radiation and phorbol ether depends on protein kinase C and reactive oxygen species].

The effects of phorbol ether (PMA) and ionizing radiation on multidrug resistance (MDR) of human larynx cancer cells HEp-2 and the dependences of these effects on protein kinase C (PKC) activity and reactive oxygen species (ROS) production were studied. MDR was determined by transport rate of rhodamine 123 off cells and production of ROS in cells was measured by means of 2'7'-dichlorodigidrofuorescein oxidation to fluorescent 2',7'-dichlorofluorescein. ROS production was increased in cells at PMA treatment.

[Antitumor effect of low-intensity extremely high-frequency electromagnetic radiation on a model of solid Ehrlich carcinoma].

The influence of different exposure regimes of low-intensity extremely high-frequency electromagnetic radiation on the growth rate of solid Ehrlich carcinoma in mice has been studied. It was shown that, at an optimum repetition factor of exposure (20 min daily for five consecutive days after the tumor inoculation), there is a clearly pronounced frequency dependence of the antitumor effect. The analysis of experimental data indicates that the mechanisms of antitumor effects of the radiation may be related to the modification of the immune status of the organism.

Determination of reactive oxygen and nitrogen species in rat aorta using the dichlorofluorescein assay.

A method for the determination of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in macroscopic sections of vessels has been developed on the basis of the dichlorofluorescein (DCF) assay. DCF was measured by fluorescence in extracts of vessels. The main artifact of the method is the oxidation of dichlorodihydrofluorescein (DCFH(2)) which is released from vessels together with DCF during the extraction procedure.

[Chronobiological aspects of gerontology].

The hypothesis of the dynamics of aging on the chronobiological grounds is presented. The results of the original research are demonstrated as well as the conclusions made by the leading authorities in the human individual annual and perennial endogenous cycles are treated. Risk-zones, which tend to increase the possibility of "mistakes" in a genetic program that lead to aging of organism are proposed.

Detection of reactive oxygen species induced by radiation in cells using the dichlorofluorescein assay.

The goal of this study was to determine the amount of reactive oxygen species (ROS) that arises inside cells irradiated in medium containing blood serum using the 2'7'-dichlorofluorescein (DCF) assay. DCF fluorescence in cells and medium was recorded on an MF44 Perkin Elmer fluorimeter, and fluorescence in cells only was recorded on a Partec flow-through cytometer. Human larynx tumor HEp-2 cells and lympholeukosis P388 cells were irradiated with X rays at a dose rate of 1.