Ultrasonic Formation of Fe3O4‑Reduced Graphene Oxide−Salicylic Acid Nanoparticles with Switchable Antioxidant Function

We demonstrate a single-step ultrasonic in situ complexation of salicylic acid during the growth of Fe3O4-reduced graphene oxide nanoparticles (∼10 nm) to improve the antioxidant and antiproliferative effects of pristine drug molecules. These nanoparticles have a precisely defined electronic molecular structure with salicylic acid ligands specifically complexed to Fe(III)/Fe(II) sites, four orders of magnitude larger electric surface potential, and enzymatic activity modulated by ascorbic acid molecules. The diminishing efficiency of hydroxyl radicals by Fe3O4-rGO-SA nanoparticles is tenfold higher than that by pristine salicylic acid in the electro-Fenton process. The H+ production of these nanoparticles can be switched by the interaction with ascorbic acid ligands and cause the redox deactivation of iron or enhanced antioxidation, where rGO plays an important role in enhanced charge transfer catalysis. Fe3O4-rGO-SA nanoparticles are nontoxic to erythrocytes, i.e., human peripheral blood mononuclear cells, but surpassingly inhibit the growth of three cancer cell lines, HeLa, HepG2, and HT29, with respect to pristine salicylic acid molecules

Graphene Oxide-Coated CuO Nanoparticles for Functionalization of Acetylsalicylic Acid and Diclofenac

A single step ultrasonic method (20 kHz, 18 W/cm2) is demonstrated for the functionalization of pristine nonsteroidal anti-inflammatory drugs: acetylsalicylic acid and diclofenac with preformed graphene oxide-coated CuO nanoparticles. These nanoparticles are positively charged and have a flower-like morphology with a mean size < 340 nm consisting of a pure CuO phase. Ultrasound causes complexation of each drug with these nanoparticles and, as a consequence, new advanced pharmaceutical nanocomposites: acetylsalicylic acid-graphene oxide-coated CuO and diclofenac-graphene oxide-coated CuO are formed. The surface composition and electronic molecular structure of these nanocomposites is modified at pH from 1 to 8 through the specific interactions involving Cu-O, C-H and H-bond formation with the carboxylic and carbonyl groups of acetylsalicylic acid, diclofenac and graphene oxide

Polyvinyl Alcohol Enhances Acetylation of Ascorbic Acid in Superparamagnetic-Graphene Oxide Nanoparticles Ultrasonically Complexed with Acetylsalicylic Acid

A single step ultrasonic method (20kHz) is demonstrated for the formation of acetylsalicylic acid-Fe3O4-graphene oxide nanocomposites (~ 80 nm) in aqueous solution. The electronic molecular structure of these nanocomposites is stable in acidic or basic aqueous medium. Coating of these nanocomposites with polyvinyl alcohol (PVA) occurs through increased binding with drug, magnetite, Fe(II)-C-O and carbonaceous network of graphene oxide. PVA-coated-acetylsalicylic acid-Fe3O4-GO nanocomposites substantially improve acetylation of pristine ascorbic acid than free unmodified drug or uncoated acetylsalicylic acid-Fe3O4-GO nanoparticles due to enhanced electron density through the presence of magnetite and graphene oxide, and specific binding of PVA with drug and ascorbic acid

Automated radiation monitoring system in zones of influence of Ignaline, Rivne, Chernobyl NPP

Автоматизированная система осуществляет метеорологический мониторинг окружающей среды и контроль радиационной обстановки в зонах влияния Ровенской, Игналинской и Чернобыльской АЭС. Использование в составе системы высокочувствительных быстродействующих спектрометрических блоков детектирования гамма-излучения позволило накапливать измеренные спектры гамма-излучения в базе данных центра реагирования и производить автоматическую идентификацию радионуклидов, фиксировать малейшие изменения радиационного фона. The automated system carries out meteorological monitoring of the environment and monitoring of the radiation situation in the influence zones of the Rivne, Ignalina and Chernobyl nuclear power plants. The use of highly sensitive high-speed spectrometric units for detecting gamma radiation in the system made it possible to accumulate the measured spectra of gamma radiation in the database of the reaction center and automatically identify radionuclides, and record the slightest changes in the radiation background

Features of reception of nanodimension diffusion layers BixY3–xFe5O12 on monocrystal substrates Y3Fe5O12

Проведены исследования элементной базы измерителей флуктуаций, оценены шумовые свойства балансных смесителей и детекторных секций, определяющих чувствительность измерений. Предложена математическая модель источников шумов балансного смесителя, определяющего чувствительность измерений, которая отражает вклад дробовых, тепловых и избыточных шумов в области низких частот. Проведены предварительные исследования уровня флуктуаций стабилизированных генераторов 3-миллиметрового диапазона длин волн