The evolution strategy-a search strategy used in individualoptimization of electrical parameters for therapeutic carotid sinusnerve stimulation

Optimization problems, arising in the search for parameters and/or techniques of functional electrostimulation (FES), disproportionally increase when multiple electrodes, electrode configurations, electrical parameters, and stimulation modes may be applied. When computational or investigational effort precludes systematic studies in FES, we propose to apply and evaluate Rechenberg's evolution strategy, which in technical use and numerical optimization has been valid in comparison to more traditional methods. This strategy implements mutation and selection processes in analogy to biological evolution. The effect of combined multiple input variables on a quality function (Q) is experimentally evaluated. The actual computed value of Q serves as a selection criterion for those input variable combinations which lead Q to approach a target value (maximization), similar to a hill-climbing procedure. In radiofrequency controlled, therapeutic electrical carotid sinus nerve stimulation (CSNS), we varied (mutated) combinations of pulse frequency and pulse amplitude parameters, according to the evolution strategy, in individual patients. CSNS lowers blood pressure and decreases heart rate. Q was computed from blood pressure and heart rate responses to CSNS. The strategy individually optimized electrical parameters to achieve large depressor responses upon CSNS. Although, in contrast to technical usage, only two input variables were investigated, and biomedical experience with the evolution strategy is limited so far, its potential use in other fields of FES, especially when more input variables are to be optimized, is discussed and encouraged.     

Thermal hystersis and quadrupole interactions in ferroelectric transitions.

It is shown that a selfconsistent calculation of the maximum amount of thermal hystersis accompanying discountinous ferroelectric transtion can be made if one takes into account the quadrupolar contribution to the effective ferroelectric field. Comparison of calculated and observed thermal hystersis in sereral ferroelectrics belonging to different families shows fair agreement.     

Late hematologic status after chemotherapy observed in patients 3 to 10 years after treatment

The aim of the present study is the evaluation of late hematological complication in patients who received aggressive chemotherapy, and were observed 3, 5 and 10 years after treatment was completed. In the group of 35 patients, besides high percent of early hematological complications, there was only one case of anemia grade 2 (acc. to WHO score). We concluded that the hematological recovery after aggressive chemotherapy was satisfactory. No secondary hematological malignancies have been found.     

The Faraday effect of natural and artificial ferritins

Measurements of the Faraday rotation at room temperature over the light wavelength range of 300-680?nm for horse spleen ferritin (HSF), magnetoferritin with different loading factors (LFs) and nanoscale magnetite and Fe(2)O(3) suspensions are reported. The Faraday rotation and the magnetization of the materials studied present similar magnetic field dependences and are characteristic of a superparamagnetic system. The dependence of the Faraday rotation on the magnetic field is described, excluding HSF and Fe(2)O(3), by a Langevin function with a log-normal distribution of the particle size allowing the core diameters of the substances studied to be calculated. It was found that the specific Verdet constant depends linearly on the LF. Differences in the Faraday rotation spectra and their magnetic field dependences allow discrimination between magnetoferritin with maghemite and magnetite cores which can be very useful in biomedicine.     

The Influence of Methyl Group Content on Tribological Properties of Organo-Silica Thin Films

Solid thin films of lubricants are often used as protection coatings of working surfaces in frictional contacts. Usually, these films have to contain stable and tribologically active additives like, for example, molybdenum disulphide or graphite. In this work chemically modified silica was investigated as a potential matrix of nanocomposite lubrication films. The sol-gel technique was used with tetraethoxysilane (TEOS) and triethoxymethylsilane (TEMS) as precursors of organo-silica thin films. Dip coating was applied as the method of film formation. Introducing a methyl group into silica by adding TEMS during sol-gel synthesis of silica films strongly increases their adhesion to the coated materials, which gives possibilities for using them on steel surfaces. The chemical properties of films synthesised by the sol-gel technique were examined by FTIR spectroscopy with the use of the transmission method. The surface topography was imaged and frictional features of organo-silica films were examined by Atomic Force Microscopy (AFM).     

Magnitude of electrogyration effect in crystals

Electrogyration Miller's delta Δ_g is checked for more than 50 crystals. The corelation between Δ_g and other quantites is discussed, similar relation for quadratic electrogyration is introduced.     

Dielectric discontinuities and multipolar interactions in ferroelectric perovskites

Ferroelectric perovskites, in particular KNbO₃, PbTiO₃ and BaTiO₃, are characterized by discontinuities in the dielectric constant at the tetragonal-cubic transition (T*) as well as by the abrupt disappearance of the spontaneous polarization which goes from a minimum finite value P_s* =P_s (T) to zero at T=T*. It is shown that, taking into account quadrupolar and higher order terms into the effective field acting on the elementary dipoles lattice, good fits to the observed P_s(T) in a wide temperature range below T* and to the inverse dielectric constant discontinuity (C/T_c)[ε₊^-1(T*)-ε_-^-1(T*)] at T⋍T* are obtained for these three perovskites.     

Malignancies of the musculoskeletal system

The induction of sister chromatid exchanges (SCEs) was investigated in mice after a ten min exposure, in vivo, to 2 MHz focused, pulse-wave ultrasound with a pulse repetition rate of 1000 Hz, pulse duration of 10 microseconds. The bone marrow cells of the pregnant female mice and the fetal liver cells were analyzed. The cell cycle specific metaphase patterns were additionally evaluated. In the bone marrow cells, the mean frequencies of SCEs were 2.77 in control, 3.56 in the cells exposed to ultrasound at 586.2 mW/cm2 (spatial average temporal average, SATA); in the fetal liver cells, 2.64 in control, 3.84 in the cells exposed. The frequencies of SCEs significantly were increased by the treatment. Faster cell kinetics was observed in fetal liver cells than bone marrow cells of pregnant female. But there was no cell-growth inhibitory effect of ultrasound on both bone marrow and fetal liver cells. In fetal liver cells, the critical acoustic power was 160.0-278.9 mW/cm2 (SATA).     

Electrogyration of pure and X-Irradiated TGS crystals

Dispersion of optical rotatory power δ, temperature dependence of δ and electrogyration of hysteresis loops of pure and X-irradiated TGS crystals have been measured, The relation between OA and P_s and the origin of OA in TGS crystal is discussed.