Introduction: Three physical conditions caused an external beam designated as a small field. The first is the loss of lateral charged particle equilibrium. The second is the effect of collimators on the primary photon source occlusion. The third condition is the size of the detector which is large compared to the field size. The most obvious perturbation effects in last condit...

Background: In this study the basic radiation properties of N-isopropylacrylamaide polymer gel dosimeter were determined together with verification of its soft tissue equivalency. Materials and Methods: The NIPAM gel was prepared and irradiated approximately 2 h after manufacturing. The magnetic resonance (MR) images were made 24 h after irradiation. The nuclear magnetic resonance (NMR) respons...

introduction the purpose of the current study was to determine optical sensitivity of n-isopropyl acrylamide nipam and polyacrylamide gelatin and tetrakis hydroxymethyl phosphoniun chloride (pagat) polymer gels for different wavelength of visible light spectrum applied in optical computed tomography method. materials and methods nipam and pagat polymer gels with conventional formulations used f...

Introduction The purpose of the current study was to determine optical sensitivity of N-isopropyl acrylamide NIPAM and polyacrylamide gelatin and tetrakis hydroxymethyl phosphoniun chloride (PAGAT) polymer gels for different wavelength of visible light spectrum applied in optical computed tomography method. Materials and Methods NIPAM and PAGAT polymer gels with conventional formulations used f...

background: in this study the basic radiation properties of n-isopropylacrylamaide polymer gel dosimeter were determined together with verification of its soft tissue equivalency. materials and methods: the nipam gel was prepared and irradiated approximately 2 h after manufacturing. the magnetic resonance (mr) images were made 24 h after irradiation. the nuclear magnetic resonance (nmr) respons...

Introduction: Polymer gel dosimeters contain chemical materials sensitive to the radiation which are polymerized by the radiation as a function of absorbed dose. So information of spatial dose distribution can be extracted by imaging from irradiated gel. Among imaging techniques, computed tomography (CT) poses as an attractive method because of practical advantages such as acce...

BACKGROUND Application of less toxic normoxic polymer gel of N-isopropyl acrylamide (NIPAM) for radiation therapy has been studied in recent years. AIM In the current study the optical and NMR properties of NIPAM were studied for radiation therapy dosimetry application. MATERIALS AND METHODS NIPAM normoxic polymer gel was prepared and irradiated by 9 MV photon beam of a medical linac. The o...

INTRODUCTION At present, the polymer gel dosimeter is considered to be the best possible dosimeter for measuring 3-dimesional radiation dose distribution in radiotherapy. These gels are normally toxic; therefore, manufacturing, handling and discarding them require special attention. In order to find less toxic recipe, N-isopropyle acrylamide polymer gel (NIPAM) was introduced. In this study, th...

Stimuli-responsive, polymer-based nanostructures with anisotropic compartments are of great interest as advanced materials because they are capable of switching their shape via environmentally-triggered conformational changes, while maintaining discrete compartments. In this study, a new class of stimuli-responsive, anisotropic nanofiber scaffolds with physically and chemically distinct compart...

We have performed small angle neutron scattering measurements (SANS) on dilute aqueous dispersions of polymer microgel particles as a function of temperature, T . The microgel particles are spherical crosslinked assemblies of a loose gel network of a poly-N-isopropylacrylamide (NIPAM) polymer. When the temperature is raised beyond a critical temperature, T(lc) approximately 32 degrees C , the p...