Experimental study of the potential of multichannel acoustic thermotomography

We describe the results of experimental studies of reconstruction of the temperature profiles from heated sources using the method of acoustic thermometry performed with the help of a multichannel scanning acoustic thermotomograph. The sensitivity of an actual system is estimated. The results of laboratory experiments on the localization of heated objects in the medium with absorption and the results of in vivo experiments on the recording of variation of the acoustic-brightness temperature of human extremities in response to an external thermal effect are presented. Institute of Applied Physics, Russian Academy of Sciences, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 5, pp. 479–484, May 1999.     

Synthesis of 1,5-benzodiazepine heterocycles containing a trifluoromethyl group

Summary 2,3-Dihydro-1,5-benzodiazepines containing a trifluoromethyl group were obtained by the reaction of ,-unsaturated ketones CF₃COCH=CR¹R² with o-phenylenediamine.M. V. Lomonosov State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10. pp. 1429–1431, October, 1994. Original article October 11, 1994.     

Dynamics of phase transitions in drying drops of human serum protein solutions

The dynamics of structuring of protein solutions in drying drops and their morphology versus the composition of dissolved proteins are studied. An increase in the content of immunoglobulins and fibronectin is shown to have an effect on the physical properties of adsorption layers at the fluid-air interface and thereby changes the dynamic parameters of structuring in drying drops. These changes are embodied in the shape of the acoustomechanical impedance curves of drying drops and can be estimated numerically. Thus, experimental support is provided for the previous phenomenological data indicating that medical diagnosis based on recording the dynamics of the acoustomechanical impedance in drying drops of blood serum is a feasibility.     

Methylation of adamantane

Russian Chemical Bulletin -     

Antioxidant and antiproliferative activities of Helleborus odorus Waldst. & Kit, H. multifidus Vis. and H. hercegovinus Martinis

This study was undertaken in order to evaluate possible antioxidative and antiproliferative activities of three Helleborus taxa. The dry leaves and roots of three Helleborus taxa were extracted with ethanol and water. A phytochemical evaluation of the selected extracts was performed using spectrophotometric methods and a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity assay was used for measuring the antioxidative activity of extracts. The antiproliferative activity of the three Helleborus taxa was studied using Burkitt's lymphoma B cells (BJAB) cell lines. The phytochemical evaluation showed that the leaves contain high levels of total phenolic and flavonoid content. Results from the DPPH assay indicated that the activity of the ethanol and water extracts of the leaves was higher than that of positive control (thymol). Extracts from the roots of H. odorus also displayed higher antioxidant activity than the positive probe, while H. mulifidus and H. hercegovinus root extracts were less effective. A statistically significant correlation between total phenolic content and antioxidative properties indicates that these compounds contribute to the antioxidant activity. The highest percentage of cell growth inhibition was observed when testing the water root extracts of H. multifidus (50.14%) and H. hercegovinus (49.04%). In contrast, the water leaf extract of H. hercegovinus exhibited the lowest inhibition of cell growth (8.59%), although it showed strong antioxidant activity.     

A therapeutically viable photo-activated manganese-based CO-releasing molecule (photo-CO-RM)

A new class of photochemically-activated CO-releasing molecule (photo-CO-RM), based on a Mn(CO)(4)(C^N) system, is reported in this study. Three CO molecules are released per CO-RM molecule. Complex 3 is a fast releaser, thermally stable in the dark and a viable therapeutic agent.     

Characteristics of dual element ultrasonic transducers in the long pulse radiation mode

The frequency and transfer characteristics of dual element ultrasonic transducers are theoretically and experimentally investigated in the long pulse radiation mode for the case where one of the piezoelectric elements is connected to a control circuit in the form of an inductance coil or a resistor. For the controlled damper and controlled layer cases, the characteristic features of radiation as functions of the control circuit parameters are determined, as well as the conditions for an increase in ultrasonic wave radiation power. With certain conditions being satisfied, we demonstrate the possibility of amplitude modulation of the emitted ultrasonic wave by periodic switching of control circuit elements.     

Positive pion production from polarized protons by linearly polarized photons in the energy range 280–420 MeV

The method is described of measuring the polarization observables Σ, P and T for the reaction γp → nπ⁺ in a double polarization experiment (polarized target + polarized beam). The measured angular distribution of these observables are presented for the photon energy range 280–420 MeV at c.m. pion emission angles between 30° and 150°. The obtained experimental data are included in the energy-independent multipole analysis of the reactions γp → Nπ.