Piotr Gas

Bio: Piotr Gas is an academic researcher from AGH University of Science and Technology. The author has contributed to research in topics: Antenna (radio) & Coaxial antenna. The author has an hindex of 12, co-authored 50 publications receiving 453 citations.

Essential Facts on the History of Hyperthermia and their Connections with Electromedicine

Abstract: The term hyperthermia is a combination of two Greek words: HYPER (rise) and THERME (heat) and refers to the increasing of body temperature or selected tissues in order to achieve a precise therapeutic effect. This paper reviews the development of thermotherapy by describing the most important moments in its history. For decades, the development of hyperthermia ran parallel with the development of cancer treatment and had numerous connections with electromedicine. Throughout its history, hyperthermia evoked a number of hopes, brought spectacular successes, but also was the subject of many disappointments.

Specifying the ferrofluid parameters important from the viewpoint of magnetic fluid hyperthermia

Abstract: The article presents the experimental study of magnetic fluid hyperthermia (MFH) utilizing magnetite nanoparticles with diameter of 15.2 nm. Temperature measurements of the ferrofluid samples were carried out in real measurement system using parallel resonance phenomenon. Based on the obtained temperature curves the basic heating parameters of ferrofluid, namely the Specific Absorption Rate (SAR) and power losses in tested nanoparticles have been specified. The authors systematize the current knowledge of these quantities and additionally propose two models that simplify their determination with given errors, omitting the mass and volume concentrations of the individual components of magnetic fluid.

Multi–Frequency Analysis For Interstitial Microwave Hyperthermia Using Multi–Slot Coaxial Antenna

Abstract: The presented paper shows a new concept of multi-slot coaxial antenna working at different frequencies to predict the best solution for interstitial microwave hyperthermia treatment. The described method concerns a microwave heating of unhealthy cells using a thin microwave antenna located in the human tissue. Therefore, the coupled wave equation in a sinusoidal steady-state and the transient bioheat equation under an axial symmetrical model are considered. The 4-Cole-Cole approximation has been used to compute the complex relative permittivity of the human tissues at different antenna operating frequencies. At the stage of numerical simulation the finite element method (FEM) is used. Special attention has been paid to estimate the optimal antenna parameters for thermal therapy for three microwave frequencies mainly used in medical practice and make comparison of the obtained results in the case of single-, double- and triple-slot antennas.

Recent Advances in Synthesis and Applications of MFe2O4 (M = Co, Cu, Mn, Ni, Zn) Nanoparticles

Abstract: In the last decade, research on the synthesis and characterization of nanosized ferrites has highly increased and a wide range of new applications for these materials have been identified. The ability to tailor the structure, chemical, optical, magnetic, and electrical properties of ferrites by selecting the synthesis parameters further enhanced their widespread use. The paper reviews the synthesis methods and applications of MFe2O4 (M = Co, Cu, Mn, Ni, Zn) nanoparticles, with emphasis on the advantages and disadvantages of each synthesis route and main applications. Along with the conventional methods like sol-gel, thermal decomposition, combustion, co-precipitation, hydrothermal, and solid-state synthesis, several unconventional methods, like sonochemical, microwave assisted combustion, spray pyrolysis, spray drying, laser pyrolysis, microemulsion, reverse micelle, and biosynthesis, are also presented. MFe2O4 (M = Co, Cu, Mn, Ni, Zn) nanosized ferrites present good magnetic (high coercivity, high anisotropy, high Curie temperature, moderate saturation magnetization), electrical (high electrical resistance, low eddy current losses), mechanical (significant mechanical hardness), and chemical (chemical stability, rich redox chemistry) properties that make them suitable for potential applications in the field of magnetic and dielectric materials, photoluminescence, catalysis, photocatalysis, water decontamination, pigments, corrosion protection, sensors, antimicrobial agents, and biomedicine.

Evaluation of magnetic nanoparticles for magnetic fluid hyperthermia.

Abstract: Background: Magnetic nanoparticles (MNPs) generate heat when exposed to an alternating magnetic field. Consequently, MNPs are used for magnetic fluid hyperthermia (MFH) for cancer treatment, and have been shown to increase the efficacy of chemotherapy and/or radiation treatment in clinical trials. A downfall of current MFH treatment is the inability to deliver sufficient heat to the tumor due to: insufficient amounts of MNPs, unequal distribution of MNPs throughout the tumor, or heat loss to the surrounding environment. Objective: In this study, the objective was to identify MNPs with high heating efficiencies quantified by their specific absorption rate (SAR). Methods: A panel of 31 commercially available MNPs were evaluated for SAR in two different AMFs. Additionally, particle properties including iron content, hydrodynamic diameter, core diameter, magnetic diameter, magnetically dead layer thickness, and saturation mass magnetization were investigated. Results: High SAR MNPs were identified. For SAR calculations, the initial slope, corrected slope, and Box-Lucas methods were used and validated using a graphical residual analysis, and the Box-Lucas method was shown to be the most accurate. Other particle properties were identified and examined for correlations with SAR values. Positive correlations of particle properties with SAR were found, including a strong correlation for the magnetically dead layer thickness. Conclusions: This work identified high SAR MNPs for hyperthermia, and provides insight into properties which correlate with SAR which will be valuable for synthesis of next-generation MNPs. SAR calculation methods must be standardized, and this work provides an in-depth analysis of common calculation methods.