Improved hyperthermia treatment control using SAR/temperature simulation and PRFS magnetic resonance thermal imaging.

Purpose: This article explores the feasibility of using coupled electromagnetic and thermodynamic simulations to improve planning and control of hyperthermia treatments for cancer. The study investigates the usefulness of preplanning to improve heat localisation in tumour targets in treatments monitored with PRFS-based magnetic resonance thermal imaging (MRTI).

Methods: Heating capabilities of a cylindrical radiofrequency (RF) mini-annular phased array (MAPA) applicator were investigated with electromagnetic and thermal simulations of SAR in homogeneous phantom models and two human leg sarcomas.

Real-time MRI-guided hyperthermia treatment using a fast adaptive algorithm.

Magnetic resonance (MR) imaging is promising for monitoring and guiding hyperthermia treatments. The goal of this work is to investigate the stability of an algorithm for online MR thermal image guided steering and focusing of heat into the target volume. The control platform comprised a four-antenna mini-annular phased array (MAPA) applicator operating at 140 MHz (used for extremity sarcoma heating) and a GE Signa Excite 1.

Fast temperature optimization of multi-source hyperthermia applicators with reduced-order modeling of 'virtual sources'.

The goal of this work is to build the foundation for facilitating real-time magnetic resonance image guided patient treatment for heating systems with a large number of physical sources (e.g. antennas).

Experimental investigation of the Jahn-Teller effect in the ground and excited electronic states of the tropyl radical. Part II. Vibrational analysis of the A 2E"3-X 2E"2 electronic transition.

Laser-induced fluorescence (LIF) and laser-excited dispersed fluorescence (LEDF) spectra of the cycloheptatrienyl (tropyl) radical C7H7 have been observed under supersonic jet-cooling conditions. Assignment of the LIF excitation spectrum yields detailed information about the A-state vibronic structure. The LEDF emission was collected by pumping different vibronic bands of the A 2E"3<--X 2E"2 electronic spectrum.

Computational investigation of the Jahn-Teller effect in the ground and excited electronic states of the tropyl radical. Part I. Theoretical calculation of spectroscopically observable parameters.

Theoretical calculations are performed for the X2E"2 and A 2E"3 states of the cycloheptatrienyl (tropyl) radical C7H7. An important goal of these calculations is to predict and to guide the analysis of the experimentally observed A 2E"3-X 2E"2 electronic spectrum. Vibrational frequencies of the tropyl radical at the conical intersection and stationary points of its X and A state Jahn-Teller distorted potential energy surfaces are given.

Towards the Validation of a Commercial Hyperthermia Treatment Planning System.

Recent developments have reinvigorated clinical investigations of hyperthermia (HT) as a viable adjuvant treatment in the fight against cancer. Researchers are placing a greater emphasis on multi-modal approaches that include mild temperatures (40°C - 43°C) and standard therapies like radiation and chemotherapy than on achieving higher temperature treatments (43°C-45°C) which were pursued in the past. The emergence of robust computer simulation tools for accurate hyperthermia treatment planning has aided this resurgence by helping improve the quality of heating.

Online feedback focusing algorithm for hyperthermia cancer treatment.

Purpose: Magnetic resonance (MR) imaging is increasingly being utilized to visualize the 3D temperature distribution in patients during treatment with hyperthermia or thermal ablation therapy. The goal of this work is to lay the foundation for improving the localization of heat in tumors with an online focusing algorithm that uses MR images as feedback to iteratively steer and focus heat into the target.

Methods: The algorithm iteratively updates the model that quantifies the relationship between the source (antenna) settings and resulting tissue temperature distribution.

Spontaneous emission from the C3 radical in carbon plasma.

Spontaneous emission measurements are discussed for the Swings transitions of the C(3) radical in laser-generated graphite plasma, and the spectroscopy of the C(3) radical in carbon vapor and plasma is summarized. A review is given of some theoretical calculations and emission spectroscopic investigations are presented. Time-averaged, laser-induced optical breakdown spectra are reported from Nd:YAG laser generated graphite microplasma.

Jahn-Teller and related effects in the silver trimer. II: vibrational analysis of the A 2E"-X 2E' electronic transition.

The laser-excited, jet-cooled A 2E"-X 2E' electronic spectrum of the silver trimer yields detailed information about its A- and X-state vibronic structure. Following extensive parameter fitting, the absorption and emission spectra are simulated and the bands are assigned. The Jahn-Teller analysis includes both linear and quadratic coupling terms, considered simultaneously with spin-orbit coupling.

Jahn-Teller and related effects in the silver trimer. I. The ab initio calculation of spectroscopically observable parameters for the X 2E' and A 2E" electronic states.

Extensive ab initio calculations were performed for the X2E' and A2E" states of Ag3, using a newly constructed basis set for Ag. An important goal of these calculations is to guide the analysis of the experimentally observed A 2E"-X2E' electronic spectrum. Vibrational frequencies of Ag(3) for both the X and A states are reported.

High resolution spectra and conformational analysis of 2-butoxy radical.

We have recorded five high resolution (200 MHz), rotationally resolved, vibrational bands of the B-X electronic transition of 2-butoxy. Two bands of the 2-butoxy spectrum have been rotationally analyzed and assigned to two different geometrical conformers of the molecule. The analyses allow the determination of the six experimental rotational constants defined by the geometry of the species in the ground (X) and excited (B) electronic states and also four spin-rotation constants for the X electronic state of the conformers.