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Results of genetic analysis of three derivatives of Azospirillum brasilense Sp245 (strains BK570, SK051, and SK248) carrying cointegrates of plasmids 85-MDa and pJFF350 (the vector for omegon mutagenesis), which manifest abnormalities in flagellation and motility, are presented. It was shown for the first time that the integration of the suicide vector into one of Azospirillum resident plasmids is accompanied by the formation of various fusion products and changes in flagellation and motility of these bacteria, such as the loss of the polar (Fla) and lateral (Laf) flagella in SK051; inactivation of Fla and Laf in SK248; and Fla-dependent acceleration of expansion in semiliquid media in BK570.

Using Omegon-Km mutagenesis, six Azospirillum brasilense Sp245 mutant derivatives lacking the capability to synthesize either one of the two major O-specific polysaccharides (O-PSs) were constructed in vivo. In all of the Lps mutants obtained, single Omegon-Km insertions were shown to be located on an indigenous plasmid DNA with molecular weight 120 MDa (p120). Physical and immunochemical analyses revealed two p120 loci coding for O-PSI and two p120 loci involved in the production of O-PSII. One of the lps loci from both groups was also shown to act in the production of Calcofluor-binding polysaccharides. It was demonstrated that two Sp245 plasmid bands with apparent molecular weights of 120 and 130 MDa (as visualized by analytical gel electrophoreses) seem to be the two topological forms of the same plasmid species (p120). Transfer properties of p120 were also examined.

Nucleation from supersaturated water vapour on different liquid substrates (n-hexadecane, decalin, 2-bromotoluene and tetrachloroethylene) has been studied experimentally by the reverse Wilson chamber method in order to obtain the dependence of the critical supersaturation on the macroscopic geometry of the three-phase system. The experimental results are interpreted on the basis of the classical theory of heterogeneous nucleation as well as in the framework of the theory of barrierless heterogeneous nucleation. The discrepancy between the measured critical supersaturations and those predicted by the classical theory is explained by the effect of a negative line tension of the three-phase contact line. The influence of the macroscopic geometry on the line tension has been investigated.

The possible conformations and packing of the macromolecular fragments in Langmuir-Blodgett films from amphiphilic polyamic acid systems with side methylene groups have been studied. From the quantomechanical and conformational calculations, models of molecular packing with extended and folded arrangement of the side chains were proposed which agree with the values obtained by X-ray analysis for the thickness of the layers in the multilayered structures.

Amphiphilic polyimides with side methylene tails and various chemical structure of the backbones have been studied in the “bulk” state (cast films) and in the form of multilayered molecular films (Langmuir films) by means of calorimetry, X-ray scattering and pressure-area diagrams.

A modified version of the reverse Wilson chamber (RWC) suitable for direct observation of droplet growth and droplet (nuclei) determination is proposed. The observed independence of nuclei number per cm2 as a function of the supersaturation is in contradiction with the classical (Volmer) theory of heterogeneous nucleation. This anomalous behaviour, however, supports our previous interpretation of heterogeneous nucleation as a barrierless process.

Magnetocrystalline anisotropy of the Mm2Co17–xZr compounds is investigated in the temperature range 78 to 290 K. At room temperatures the effective anisotropy constant increases with x. The resultant uniaxial anisotropy is weakened with the decrease of the temperature. The temperature depencence of magnetization measured in weak fields normal to the c-axis shows a well expressed rise at 140 K with cooling. This behaviour is ascribed to a competition between the planar rare-earth and uniaxial cobalt anisotropies which exhibit different temperature behaviour. Im Temperaturbereich von 78 bis 290 K wird die magnetokristalline Anisotropie von Mm2Co17–xZx-Verbindungen untersucht. Bei Zimmertemperatur nimmt die effektive Anisotropiekonstante mit x zu. Die resultierende einachsige Anisotropie wird mit abnehmender Temperatur schwacher. Die Temperaturabhangigkeit der Magnetisierung, in schwachen Feldern senkrecht zur c-Achse gemessen wird, zeigt einen ausgepragten Anstieg wahrend der Abkuhlung bei 140 K. Dieses Verhalten wird der Konkurrenz zwischen der planaren Seltenerd- und einachsigen Kobalt-Anisotropie zugeschreiben, die verschiedenes Temperaturverhalten aufweisen.

Recently we discovered that in developed integrated flow cytometry using combination high resolution transmission and two beam (pump-probe) of photothermal microscopy with flow module the temporal fluctuation of probe beam even without pump laser pulse are very sensitive to functional states of single cells (e.g. with 2-3 differences in average fluctuation amplitude for live and dead cells). In this paper we are focusing on theoretical and experimental studies of these new phenomena using thermolens schematics with highly stabilized continuous-wave He-Ne laser and photodiode/photomultiplier with pinhole. This scheme allows to study both random and laser-induced thermolens effects in passive and active mode including short and long term monitoring of scattered light fluctuation in transillumination mode at single cellular and even sub-cellular levels in vitro, and in vivo. We demonstrate these schematics has some potential to monitor intracellular dynamics including change in cell metabolism, and necrosis, especially, under pump laser impacts in vitro in stationary condition. Besides, we present some relevant data obtained with other similar schematics, including evaluation of bacterial motility by dynamic light scattering.We discuss further potential developing this approach for flow cytometry with fast speed photodetector and digital camera and the multi- wavelength statistical and correlation analysis of speckle-related signals in applications to analysis of complex motions and functional properties of cells in bioflows including the evaluation of the rotational and translational components of the motion of individual live and dead cells.

The easy- and hard-axis magnetization behaviour has been studied in detail in a Mm 2 Co 16.5 Zr 0.5 pseudomonocrystal, where Mm is cerium misch-metal, in the temperature range 4.2–290 K. At room temperature, the magnetocrystalline anisotropy of the compounds is uniaxial with the easy direction along the c -axis of the hexagonal cell. However, when the temperature decreases the anisotropy becomes cone-like, with the easy directions forming at 8 K a cone with an angle of 70° with respect to the c -axis. This transition is explained in terms of the competition between the anisotropies of the Co and R sublattices.

Azospirillum brasilense Sp245 has a mixed type of flagellation: a single polar flagellum (Fla) is synthesized constitutively, and abundant lateral flagella (Laf) are produced only in solid and semisolid media. In the present study, Omegon-Km Fla-Laf-, Fla-Laf+, Fla-/Mot-Laf-. Fla-/Mot-Laf+, Mot-Laf-, and Che- mutants of Sp245 were constructed in vivo. In some of the mutants, a number of cells possessed from 1 to 5 subpolar long flagella (Sfl). These Sfl provided the host cells with unusual motility patterns. Mutants producing shortened Fla and Laf were also detected. In the mutants still producing Laf, their expression retained the wild-type inducibility. However, all the mutants described were unable to form swarm rings in semisolid media. The results suggest the existence of common control or structural elements in assembly and rotation apparatus of both Fla and Laf systems. Single Omegon-Km insertions were localized in 85 MD (in two mutants) and in 120 MD (in one mutant) indigenous plasmids, as well as to least in two different regions of chromosomal DNA (in other mutants).