MR monitoring of focused ultrasound surgery in a breast tissue model in vivo

The objective of this study was to investigate MRI methods for monitoring focused ultrasound surgery (FUS) of breast tumors. To this end, the mammary glands of sheep were used as tissue model. The tissue was treated in vivo with numerous single sonications which covered extended target volumes by employing a scanning technique. The ultrasound focus position was controlled by online temperature mapping based on the temperature dependence of the relaxation time T(1). This approach proved to be reliable and offers thus an alternative to proton resonance frequency methods, whose application is hampered in fatty tissues. FUS-induced tissue changes were visible on T(2)- as well as on pre- and post-contrast T(1)-weighted images. According to our initial experience, noninvasive MRI-guided FUS of breast tumors is feasible.     

Minicomputer control of measurements of spectroelectrochemical processes: Part 2. A New Measurement System for Simultaneous Coulometric and Spectrophotometric Investigations

The design of a system for simultaneous coulometric and spectrophotometric measurements is described. A special fiber optic cell is coupled to a rapid scanning spectrophotometer. The assembly is controlled by a Nova-2 minicomputer which simultaneously acquires and processes the data. The programmed measurement procedures enable spectrophotometric and coulometric curves to be recorded for linear or stepped sweep of the electrode potential, and kinetic relations to be found for a constant electrode potential. Test measurements on chlorpromazine and trifluoroperazine showed that the system is useful for studies of kinetics and mechanisms of electrode processes. The advantages and disadvantages of the method are discussed.     

226Ra and 222Rn concentrations of spring waters in Balaton Upland of Hungary and the assessment of resulting doses

²²²Rn and ²²⁶Ra concentration of 18 frequently visited and regularly used, consumed spring waters on the Balaton Uplands have been measured by radon emanation method and alpha-spectrometry. ²²²Rn concentration varied between 1.5-55 Bq/l while ²²⁶Ra concentration between -601 mBq/l. The expected dose, between 14.1-119 mSv/y, has been assessed from the value of concentration supposing a daily consumption of 1 liter.     

The synthesis of 1,2,3,3a,4,5,6,11-octahydro-6,11a-methano-11aH-benzo[4,5]cycloocta[1,2-c]pyrroles. As new heterocyclic ring system

The synthesis of the novel 1,2,3,3a,4,5,6,11-octahydro-6,11a-methano-11aH-benzo[4,5]cycloocta[1,2-c]-pyrrole system by acid-catalyzed cyclization of cis-3a-benzyl-3a,4,7,7a-tetrahydro-1H-isoindole-1,3(2H)-diones is described.     

Fission of a slab of charged nuclear matter in the time-dependent hartree fock (TDHF) theory

The time evolution of a slab of charged nuclear matter is studied within the TDHF method as a function of the initial conditions. The effective interaction is of Skyrme type plus a repulsive Yukawa interaction representing the Coulomb repulsion. The implications on the time evolution of specific collective as well as intrinsic excitations are investigated. Fission is found to occur at large enough excitation energies for a variety of initial conditions after timest _fi ≈(1–3)·10^?21 s. The final disintegration of the slab (“snatching”) is characterized by arapid rise of a potential barrier between the nascent fragments, the rise occurring int _sn≈0.2·10^?21 s. The importance for the fission process of the reflection symmetry of the occupied single particle states is demonstrated.