A New View on the Application of Gold Nanoparticles in Cancer Therapy

In biomedical research and the practice of cancer therapy, gold nanoparticles have been used to visualize malignant tumors, as the heated bodies for hyperthermia of cancer cells, as drug carriers to deliver drugs to a cancer cell, but, to the best of our knowledge, they have not yet been used consciously as the sources of terahertz (THz) radiation delivered to a cancer cell that contributes to the inhibition of cell activity. It is predicted here that gold nanoparticles less than 8 nm in size are sources of spontaneous THz radiation, and the possibility of their application in oncology is due to the known effects of THz radiation on the cells of living organisms. There are indications that nanoparticles with a size comparable to the width of the major groove of the DNA molecule will be the most effective. Another effect that has not yet been taken into account in biomedical studies using gold nanoparticles is that of local electric fields due to the contact potential difference above edges and vertices of gold nanoclusters. The prerequisites and possibilities for searching for the manifestations of these two effects when gold nanoparticles are introduced into living cells of organisms are considered.Comment: 29 pages, in Russian, 15 figure

On modelling of microwave heating of a ceramic material

A simple model is proposed and tested for simulations of ceramic processing by microwave heating. The model is based on a piecewise constant approximation of the material properties and makes it possible to separate and analyse different effects caused by the sample shape and the dependence of the material properties on temperature. Specifically, the simulation results demonstrate that microwave heating of an alumina sample can be very sensitive to a variation of its dielectric constant with temperature. For different geometries, there is a similarity in the dependences of the thermal state characteristics ( temperature drop across the sample, amount of dissipated power and electric field amplitude at the sample centre) on maximal temperature. It is shown also that a temperature drop between the sample centre and surface can be strongly enhanced in the case of a spherical sample irradiated symmetrically by microwaves