Components of plants of the family Empetraceae. II. Flavonoids of Empetrum nigrum

Tomsk Medical Institute. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 875–876, November–December, 1988.     

An NMR, DSC, and IR spectroscopy study of the composite formed during low-temperature postradiation polymerization of C2F4 in the presence of a 3D graphene material

By solid-state magic angle-spinning nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), and IR spectroscopy, polytetrafluoroethylene (PTFE) samples obtained by low-temperature (T = ?196°C) postradiation polymerization of tetrafluoroethylene (C₂F₄) and C₂F₄ mixtures with a 3D graphene material formed by the microwave exfoliation of graphite oxide films (MEGO) have been investigated. It has been shown that the melting point of PTFE in the PTFE-MEGO composite is 332.5°C, which is 8.8°C above the melting point of pure PTFE obtained under the same conditions. According to the measured values of specific enthalpy of melting ΔH _m (51.5 and 45.4 J/g), the degrees crystallinity (x _c) of 0.63 and 0.55 have been calculated for the pure polymer and the composite, respectively. It has been also found that none of the PTFE-containing samples examined has terminal CF₃ groups typical of PTFE prepared by conventional suspension polymerization.     

Effect of Tetrafluoroethylene Concentration on Thermophysical Characteristics and Structure of Products of Its Radiation Telomerization in Flutec PP3

High Energy Chemistry - The influence of monomer concentration on the properties of radiation-synthesized tetrafluoroethylene telomers in perfluoro-1,3-dimethylcyclohexane has been studied by...     

Floating Electrode Dielectric Barrier Discharge Plasma in Air Promoting Apoptotic Behavior in Melanoma Skin Cancer Cell Lines

Initiation of apoptosis, or programmed cell death, is an important issue in cancer treatment as cancer cells frequently have acquired the ability to block apoptosis and thus are more resistant to chemotherapeutic drugs. Targeted and perhaps selective destruction of cancerous tissue is desirable for many reasons, ranging from the enhancement of or aid to current medical methods to problems currently lacking a solution, i.e., lung cancer. Demonstrated in this publication is the inactivation (killing) of human Melanoma skin cancer cell lines, in vitro, by Floating Electrode Dielectric Barrier Discharge (FE-DBD) plasma. Not only are these cells shown to be killed immediately by high doses of plasma treatment, but low doses are shown to promote apoptotic behavior as detected by TUNEL staining and subsequent flow cytometry. It is shown that plasma acts on the cells directly and not by “poisoning” the solution surrounding the cells, even through a layer of such solution. Potential mechanisms of interaction of plasma with cells are discussed and further steps are proposed to develop an understanding of such systems.     

Crystalline fullerene deuteride C60D24: Spectral investigation

X-ray diffraction patterns, infrared and x-ray photoelectron spectra, and electron energy-loss spectra are obtained for fullerene deuteride C₆₀D₂₄ prepared by treating solid C₆₀ with D₂ gas. It is established that the deuteride is a polycrystalline powder with an fcc lattice (a ₀=14.55 Å). The product of thermal decomposition of the deuteride consists mainly of fullerene molecules separated by a distance much greater than in the initial fullerite.     

Orientational order of a nematic polymer grafted on polytetrafluoroethylene

The orientation behavior of a nematic side‐chain polymer grafted on polytetrafluoroethylene (PTFE) is studied. The sandwich‐like composite was prepared by the graft post‐polymerization of 4‐cyan‐4′‐(biphenyloxy)butyl acrylate on a PTFE film pretreated by vacuum ultraviolet irradiation (VUV). The oriented liquid crystal layer was prepared by mechanical stretching of the composite film. Orientation degree was measured by means of FT‐IR spectroscopy. The orientation function increases with the increasing strain and attains the upper limit value at the strain Δl/l > 1.0. The temperature dependence of the orientation degree is completely reversible under cooling and heating. Copyright © 2000 John Wiley & Sons, Ltd.     

Plasma medicine

Different aspects of plasma medicine, the new branch interdisciplinary between plasma chemistry and medicine, are considered. It was shown that complex biological processes in living tissues and bodies can be controlled, stimulated, catalyzed, and diagnosed with the use of low-temperature, atmospheric-pressure air plasma. It was found that discharge plasma can produce the desired therapeutic effect in wound sterilization and healing, as well as in treatment of some skin diseases. The action of plasma is harmless for the human body under definite conditions and exerts a targeted, nondestructive therapeutic effect.     

Plasmochemical modification of fluorocarbon polymers for creation of new hemocompatible materials

The various plasmochemical technique for the surface functionalization and regulation of the biological characteristics of fluorocarbon polymers aimed at the enhance their blood compatibility are described. The plasmochemical treatment in oxygen and nitrogen containing gases has been used to increase of surface energy and hydrophoby of fluorocarbon polymers. Modification of the surface morphology and chemical structure to improve thromboresistive properties of polymers by plasma etching and deposition of biocompatible materials was demonstrated and discussed. Plasma-assisted immobilization of proteins in combination with other plasma modification methods provides a promising technique for engineering of a new generation of hemocompatible materials.