Hepatitis C virus (HCV) is one of the major causes of chronic liver disease and leads to cirrhosis and hepatocarcinoma. Despite extensive research, there is still no vaccine against HCV. In order to induce an immune response in DBA/2J mice against HCV, we obtained modified mouse mesenchymal stem cells (mMSCs) simultaneously expressing five nonstructural HCV proteins (NS3-NS5B). The innate immune response to mMSCs was higher than to DNA immunization, with plasmid encoding the same proteins, and to naïve unmodified MSCs. mMSCs triggered strong phagocytic activity, enhanced lymphocyte proliferation, and production of type I and II interferons. The adaptive immune response to mMSCs was also more pronounced than in the case of DNA immunization, as exemplified by a fourfold stronger stimulation of lymphocyte proliferation in response to HCV, a 2.6-fold higher rate of biosynthesis, and a 30-fold higher rate of secretion of IFN-γ, as well as by a 40-fold stronger production of IgG2a antibodies to viral proteins. The immunostimulatory effect of mMSCs was associated with pronounced IL-6 secretion and reduction in the population of myeloid derived suppressor cells (MDSCs). Thus, this is the first example that suggests the feasibility of using mMSCs for the development of an effective anti-HCV vaccine.

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Low-frequency transducers with dry dot contact (or dry point contact (DPC)) allow to overcome the problems of ultrasonic contact in testing of concrete. With the help of these transducers, it is possible to carry out the testing of concrete and other solid materials with longitudinal and shear waves. The principle of operation and device of ultrasonic low-frequency piezoelectric transducers with DPC, which are generating on the surface of solid body normal and tangential oscillatory force are shown. Directional diagrams of acoustic fields of these transducers, waveform of signals and their spectrums are given. Also shown possible areas of application of these transducers, in particular for flaw detection and testing of strength of concrete structures.The ultrasonic testing of concrete and ferroconcrete is possible on the frequencies not more the 150 -200 kHz. Rough, often undulating and porous surface of concrete structures demands special and laborious preparations for achieving the acceptable quality of acoustic contact through the liquid.Testing of the concrete with through-sounding method and more over surface sounding needs the knowledge of the base of sounding with the possible more exactness. To reach that the sizes of probe operating surface should be decreased to the limit. When testing the concrete with the echo method the space selection of the reflector is needed, that can be achieved with the help of big wave size probe or with the help of synthetic aperture focused technique (SAFT). SAFT assumes the usage of small wave size probe. Besides for some purposes, that can be served both with the sounding method and echo method, the transducers with a short duration of transformable impulses and with a low level of self reverberation noise are needed.All these conflicting objectives to ultrasound transducers for testing of the concrete were successfully satisfied by invention of the lowfrequency transducer with dry point contact (DPC).The essence of the DPC is: the size of the acoustic contact zone of oscillating probe surface with the surface of the test object is many times smaller than the length of the ultrasound wave. So when the wavelength is 40 mm (the typical value of wavelength while testing the concrete with ultrasound) the contact with the size of the zone less then 1-2 mm can be considered as point contact. In this case the contact liquid makes no influence on the coefficient of signal transformation and became useless. The transducer acts on the test object surface as a point oscillating force.The principle of DPC is already known for a long time and is used in different low-frequency ultrasound devices [1,2]. For testing the concrete structures the low-frequency transducers with half-waved concentrator are used [3]. The concentrators are the resonant elements that collect oscillations of rather big aperture of transducer in the point of contact.Our low-frequency transducers with DPC differ from the transducers with concentrators by the three main specialties. First, the size of the element th...

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