The mechanisms underlying the cytotoxic action of pure fullerene suspension (nano-C60) and water-soluble polyhydroxylated fullerene [C60(OH)n] were investigated. Crystal violet assay for cell viability demonstrated that nano-C60 was at least three orders of magnitude more toxic than C60(OH)n to mouse L929 fibrosarcoma, rat C6 glioma, and U251 human glioma cell lines. Flow cytometry analysis of cells stained with propidium iodide (PI), PI/annexin V-fluorescein isothiocyanate, or the redox-sensitive dye dihydrorhodamine revealed that nano-C60 caused rapid (observable after few hours), reactive oxygen species (ROS)-associated necrosis characterized by cell membrane damage without DNA fragmentation. In contrast, C60(OH)n caused delayed, ROS-independent cell death with characteristics of apoptosis, including DNA fragmentation and loss of cell membrane asymmetry in the absence of increased permeability. Accordingly, the antioxidant N-acetylcysteine protected the cell lines from nano-C60 toxicity, but not C60(OH)n toxicity, while the pan-caspase inhibitor z-VAD-fmk blocked C60(OH)n-induced apoptosis, but not nano-C60-mediated necrosis. Finally, C60(OH)n antagonized, while nano-C60 synergized with, the cytotoxic action of oxidative stress-inducing agents hydrogen peroxide and peroxynitrite donor 3-morpholinosydnonimine. Therefore, unlike polyhydroxylated C60 that exerts mainly antioxidant/cytoprotective and only mild ROS-independent pro-apoptotic activity, pure crystalline C60 seems to be endowed with strong pro-oxidant capacity responsible for the rapid necrotic cell death.

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An electronic circuit for analog processing of neural (electroneurogram or ENG) and muscular (electromyogram or EMG) signals in functional electrical stimulation (FES) systems is described in this paper. The basic circuit consists of a low-noise gated preamplifier, band-pass filter, amplifier, and a blanking circuit to minimize stimulation artifacts during electrical stimulation. This device was tested in chronic recordings using a triphasic cuff electrode for nerves and epimysial electrodes for muscles in the hind limbs of cats. The device was used for nerve recordings in the presence of electrical stimulation of muscles in the same leg. The recordings showed rejection of stimulation and muscle (M-wave) artifacts, while retaining the information of interest.

The greatest dimensional changes of addition and condensation silicone impressions appear in the first hour after their separation from the model.

The aim of the present investigation was to determine the correlation in the blood concentrations of thyroid hormones, lipids and glucose as well as the content of lipids in the liver of dairy cows in the transitional period.The animals (n = 40) were divided into four groups: the first group included late pregnant cows (n = 10) from the 10 th to 4 th day before calving; the second group included late pregnant cows (n = 10) from the 4 th to 1 st day before calving; the third group included clinically puerperal healthy cows (n = 10), whereas the fourth group included puerperal cows with clinical symptoms of ketosis (n = 10). Samples of liver and blood tissues were taken from all cows. Pathohistological examination of liver samples showed statistically significantly higher (p < 0.01) lipid infiltration in ketotic cows compared to healthy cows in late pregnancy and puerperium. Biochemical examination of blood serum showed significantly higher values (p < 0.01) of free fatty acids in ketotic cows, such as significantly lower blood concentrations of glucose (p < 0.01), triacylglycerols (p < 0.01), total cholesterol (p < 0.05), triiodthyronine (p < 0.05) and thyroxine (p < 0.05), compared to the values obtained in the blood serum in the groups of healthy cows before and after calving. In this study, significantly positive correlations were determined between the content of lipids in the liver and blood concentration of free fatty acids (r = 0.51; p < 0.05) as well as the negative ones between the content of lipids in the liver and blood concentrations of glucose (r = -0.69; p < 0.05), triacylglycerols (r = -0.55; p < 0.05) and total cholesterol (r = -0.50; p < 0.05) in the group of ketotic cows. Our investigations suggested that a hypothyroidal status was established in ketotic cows and that the blood concentrations of free fatty acids, triacylglycerols, total cholesterol and glucose served as major biochemical indicators in determining liver steatosis in the dairy cows in the transitional period.

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The influence of the mechanical activation of ZnO nanoparticle fillers on the structural and electrical properties of the matrix of poly(vinylidenefluoride)-ZnO (PVDF-ZnO) films was investigated. Transmission electron microscopy and scanning electron microscopy analyses showed that mechanical activation in a high energy planetary ball mill reduces the size of ZnO particles. X-ray diffraction and Raman spectroscopy revealed that PVDF crystallized predominantly as the -phase. Non-activated ZnO filler reduces the degree of the crystallinity of the matrix and promotes crystallization of α-phase of PVDF in the film, while the fillers activated for 5 and 10 min induce crystallization of -phase, indicating that mechanical activation of the filler can be used as a general method for fabrication of PVDF composites with increased content of piezoelectric -phase crystals.Dielectric spectroscopy measurements show that polymer composite with the high content of -phase (with ZnO filler activated for 5 min) exhibits the highest value of dielectric permittivity in 150-400 K range of temperatures. Kinetic analysis shows combined effects of increased surface area and increased concentration of surface defects on the interactions between polymer chains and activated nanoparticles.

The Stark widths (W) of 12 neutral and 16 singly ionized tin (Sn I and Sn II, respectively) spectral lines have been measured in a laboratory helium plasma at 13 000 K electron temperature and 5.1 × 1022 m−3 electron density. Many of them are the first data in the literature. At mentioned plasma conditions, the Stark broadening has been found to be the dominant mechanism in line shape formation. The modified version of the linear, low-pressure, pulsed arc was used as a plasma source operated in helium with tin atoms, as impurities, evaporated from tin cylindrical plates located in the homogeneous part of the discharge, providing conditions free of self-absorption. Our Sn II W values are compared to the recent theoretical data calculated on the basis of the modified semi-empirical approach and, also, to the existing experimental W values. Our normalized Stark widths are much smaller (up to a factor of 4, on average) than those measured in a laser-produced plasma and in a plasma created by the shock-wave tubes. An agreement, within the accuracy of the experiment and uncertainties of the used theoretical approach, with the recent calculated W data was found. Our normalized Sn I Stark widths are much smaller than those observed in the mentioned plasma sources.