Introgressions of Vitis rotundifolia Michx. to obtain grapevine genotypes with complex resistance to biotic and abiotic stresses.

Vitis rotundifolia Michx. is one of the species of the family Vitaceae, with resistance to both biotic and abiotic stresses. The present study reports new scientif ic knowledge about the inheritance of resistance to downy mildew, powdery mildew and frost by V. vinifera varieties from V. rotundifolia. Recombinant lines of three hybrid populations from the crossing of the maternal genotype ♀M. 31-77-10 with V. rotundifolia hybrids were used as the object of the study. As a result of laboratory screening, more than 40 % of recombinants of the ♀M. 31-77-10 × × [DRX-M5-734 + DRX-M5-753 + DRX-M5-790] population showed a high degree of frost resistance (-24 °C), while 6 % of transgressive recombinants were characterized by a very high degree of resistance (-27 °Ð¡). The maternal genotype ♀M. 31-77-10 does not carry alleles of resistance to powdery mildew at the Run1 locus and in the f ield suffers from powdery mildew much more than the paternal genotypes. The prevalence of powdery mildew on vegetative organs in the three recombinant populations over the years varies on average between 3.2-17.1, 0.3-17.7 and 0.6-5.2 %, respectively. As a result, almost all recombinant genotypes that received a resistant allele from the paternal genome are highly resistant to powdery mildew.

Nanostructuring few-layer graphene films with swift heavy ions for electronic application: tuning of electronic and transport properties.

The morphology and electronic properties of single and few-layer graphene films nanostructured by the impact of heavy high-energy ions have been studied. It is found that ion irradiation leads to the formation of nano-sized pores, or antidots, with sizes ranging from 20 to 60 nm, in the upper one or two layers. The sizes of the pores proved to be roughly independent of the energy of the ions, whereas the areal density of the pores increased with the ion dose. With increasing ion energy (>70 MeV), a profound reduction in the concentration of structural defects (by a factor of 2-5), relatively high mobility values of charge carriers (700-1200 cm2 V-1 s-1) and a transport band gap of about 50 meV were observed in the nanostructured films. The experimental data were rationalized through atomistic simulations of ion impact onto few-layer graphene structures with a thickness matching the experimental samples. We showed that even a single Xe atom with energy in the experimental range produces a considerable amount of damage in the graphene lattice, whereas high dose ion irradiation allows one to propose a high probability of consecutive impacts of several ions onto an area already amorphized by the previous ions, which increases the average radius of the pore to match the experimental results. We also found that the formation of "welded" sheets due to interlayer covalent bonds at the edges and, hence, defect-free antidot arrays is likely at high ion energies (above 70 MeV).

[MODERN METHODS OF PHYSICAL-CHEMICAL RESEARCH IN GASTROENTEROLOGY PRACTICE: THE EXPERIENCE OF INTERACTION].

UNLABELLED: The aim of this work was to assess the potential of some physical and chemical methods for studying erythrocytes and blood serum in gastroenterological practice by the example of colorectal cancer (CC). MATERIALS AND METHODS: A total of 26 persons with various stages of colorectal cancer and 16 healthy (control group) were examined. Parameters of erythrocytes and blood serum were investigated by light microscopy, dielectrophoresis in a non-uniform alternating electric field (DEF in NUAEF), terahertz spectroscopy, ellipsometry, Raman-spectroscopy. RESULTS: Polymorphism of erythrocytes, rigidity, viscosity, indexes of aggregation and destruction were significantly higher in patients with CC and polarizability, amplitude of erythrocyte deformation in NUAEF being lower than those in the controls. The study of erythrocytes by terahertz spectroscopy revealed the low levels of amplitude transmittance over the whole frequency range in CC patients compared to the controls. The increasing of refractive index, degree of heterogeneity of thin films obtained from the serum in CC patients were observed in considering the ellipsometric parameters. We found a significant increasing of the concentration of antigens to CD24 at the early stage of the disease. The areas of some peaks in Raman spectra were significantly lower in patients with CC compared to the healthy ones, it is possible due to a carotin deficiency. Most of the studied parameters were correlated with the stage of the disease. A set of optical methods for studying blood serum compared with those of histology and radiological methods of diagnosis showed their high sensitivity and specificity, positive and negative predictive value (80 % and above). CONCLUSION: The obtained results of the pilot study demonstrate the prospects of using physical and chemical methods of research of erythrocytes and blood serum for early diagnosis, stage of disease and monitoring the effectiveness of treatment of CC.

Crystallization of amorphous Si nanoclusters in SiO(x) films using femtosecond laser pulse annealings.

The SiO(x) films of various stoichiometries deposited on Si substrates with the use of the co-sputtering from two separate Si and SiO2 targets were annealed by femtosecond laser pulses. Femtosecond laser treatments were applied for crystallization of amorphous silicon nanoclusters in the silicon-rich oxide films. The treatments were carried out with the use of Ti-Sapphire laser with wavelength 800 nm and pulse duration about 30 fs. Regimes of crystallization of amorphous Si nanoclusters in the initial films were found. Ablation thresholds for SiO(x) films of various stoichiometries were discovered. The effect of laser assisted formation of a-Si nanoclusters in the non-stoichiometric dielectric films with relatively low concentration of additional Si atoms was also observed. This approach is applicable for the creation of dielectric films with semiconductor nanoclusters on non-refractory substrates.

Extremely high response of electrostatically exfoliated few layer graphene to ammonia adsorption.

Extremely high gas sensing properties of p-type few layer graphene flakes exfoliated from highly oriented pyrolytic graphite have been demonstrated. The current response to ammonia adsorption is strongly dependent on film thickness and is higher than that for graphene by 1-8 orders of magnitude. A maximal response was found for sample thickness ∼ 2 nm. The effect is attributed to the formation of multiple p-n-p junctions at the grain boundaries in the polycrystalline graphene flakes exposed to ammonia-containing ambient.

The modification of Si nanocrystallites embedded in a dielectric matrix by high energy ion irradiation.

We have followed the effects of heavy ion irradiation on the structural, electrical, and photoluminescence properties of ensembles of silicon nanocrystallites embedded in a dielectric (SiO(2)) matrix. This was done as a function of the irradiation dose and the content of the Si phase. The results obtained can be accounted for self-consistently assuming that a relatively small dose of the irradiation enhances the crystallization while for higher doses the irradiation enhances the amorphization. The corresponding processes suggest that tuning of the above properties can be achieved by swift heavy ion irradiation.

A novel tip-induced local electrical decomposition method for thin GeO films nanostructuring.

Decomposition of germanium monoxide (GeO) films under the impact of an atomic force microscope (AFM) tip was observed for the first time. It is known that GeO is metastable in the solid phase and decomposes into Ge and GeO(2) under thermal annealing or radiation impact. AFM tip treatments allow us to carry out local decomposition. A novel tip-induced local electrical decomposition (TILED) method of metastable GeO films has been developed. Using TILED of 10 nm thin GeO film, Ge nanowires on silicon substrates were obtained.

Effect of the growth rate on the morphology and structural properties of hut-shaped Ge islands in Si(001).

The effect of Ge deposition rate on the morphology and structural properties of self-assembled Ge/Si(001) islands was studied. Ge/Si(001) layers were grown by solid-source molecular-beam epitaxy at 500 °C. We adjusted the Ge coverage, 6 monolayers (ML), and varied the Ge growth rate by a factor of 100, R = 0.02-2 ML s(-1), to produce films consisting of hut-shaped Ge islands. The samples were characterized by scanning tunnelling microscopy, Raman spectroscopy, and Rutherford backscattering measurements. The mean lateral size of Ge nanoclusters decreases from 14.1 nm at R = 0.02 ML s(-1) to 9.8 nm at R = 2 ML s(-1). The normalized width of the size distribution shows non-monotonic behaviour as a function of R and has a minimum value of 19% at R = 2 ML s(-1). Ge nanoclusters fabricated at the highest deposition rate demonstrate the best structural quality and the highest Ge content (∼0.9).