In the present study, we fabricated a hemoglobin/gold nanoparticle (Hb/GNP) heterolayer immobilized on the Au micro-gap to confirm H₂O₂ detection with a signal-enhancement effect. The hemoglobin which contained the heme group catalyzed the reduction of H₂O₂. To facilitate the electron transfer between hemoglobin and Au micro-gap electrode, a gold nanoparticle was introduced. The Au micro-gap el...

Radiotherapy which consists of external beam radiotherapy (EBRT) and internal radioisotope therapy (RIT), has a wide usage for treating cancer as clinical trials.This study provides some conditions to prove that tungsten oxide nanoparticles (WO3) is a radiosensitizer.The peripheral blood mononuclear cells (PBMCs) were used to calculate inhibitory concentration (IC).The AGS cell line exposed the...

Adequate description of electro and gamma nuclear physics is of utmost importance in studies of electron beam-dumps and intense electron beam accelerators. I also is mandatory to describe neutron backgrounds and activation in linear colliders. This physics was elaborated in Geant4 over the last year, and now entered into the stage of practical application. In the Geant4 Photo-nuclear data base ...

Modeling the radio-induced effects in biological medium still requires accurate physics models to describe the interactions induced by all the charged particles present in the irradiated medium in detail. These interactions include inelastic as well as elastic processes. To check the accuracy of the very low energy models recently implemented into the GEANT4 toolkit for modeling the electron sl...

Objective(s): Normoxic MAGIC-f polymer gels are established dosimeters used for three dimensional dose quantifications in radiotherapy. Nanoparticles with high atomic number such as gold are novel radiosensitizers used to enhance doses delivered to tumors. The aim of this study was to investigate the effect of gold nanoparticles (GNPs) in enhancing percentage depth doses (PDDs) within the MAGIC...

Radiation therapy is an established method of cancer treatment. New technologies in cancer radiotherapy need a more accurate computation of the dose delivered in the radiotherapy treatment plan. This study presents some results of a Geant4-based application for simulation of the absorbed dose distribution given by a medical linear accelerator (LINAC). The LINAC geometry is accurately described ...

objective(s): in this study we evaluate the impact of the different aspects of gold nano-particles (gnps) on the target absorptive dose enhancement factor (def) during external targeted radiotherapy with photon beams ranging from kilovolt to megavolt energies using monte carlo simulation. methods: we have simulated the interaction of photon beams with various energies of radiation using water s...

gold nanoparticles were synthesized by chemical reduction of haucl4 inside the pores of a polycarbonate-based membrane followed by dissolving the membrane in dichloromethane and further sonication. sonication time as the main affecting factor on the nanoparticle size was investigated. the characterization by transmission electron microscopy showed the formation of gold nanoparticles with diamet...

MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd)-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitati...

the monte carlo method can be used to describe any technique that approximates solutions to quantitative problems through statistical sampling. this method is considered to be the most accurate method for dose calculation in radiotherapy. for complete modeling of a linear accelerator, it is required that the manufactured information covers all data, but some data such as primary electron energy...