Structural evolution and dielectric properties of suspensions of carbon nanotubes in nematic liquid crystals.

Structuring of carbon nanotubes (CNTs) in liquid crystals (LCs) and electro-physical characteristics of LC + CNT suspensions were studied in a very broad range of CNT concentrations, C, from 10-5 wt% (highly diluted suspensions) to 2.5 wt% (highly viscous suspensions). Along with the conventional sandwich cells with the transparent electrodes on the substrates, we used the cells with the in-plane applied electrical field in order to monitor changes of electrical parameters in the same direction as the structural changes observed under an optical microscope. The data revealed four stages of structural evolution with the increase of C: (1) dispersion of individual CNTs and their very small aggregates (C < 3 × 10-4 wt%), (2) presence of branched aggregates with a non-compact structure (C = 3 × 10-4-5 × 10-3 wt%), (3) percolation of non-compact aggregates (C = 5 × 10-3-10-1 wt%) and (4) compaction of aggregates and formation of a dense network (C = 10-1-1 wt%). In the studied concentration range, the conductivity displayed two percolation thresholds at C ≈ 0.004 wt% and C ≈ 0.5 wt%, which are associated with the formation of a non-compact and dense CNT network. By contrast, the permittivity ε' revealed only one percolation threshold at C ≈ 0.5 wt%, when the distance between the adjacent CNTs becomes incredibly small.

[State of intestinal microbiota in patients with type 2 diabetes mellitus and non-alcoholic fatty liver disease].

High prevalence of type 2 diabetes mellitus (DM) and nonalcoholic fatty liver disease (NAFLD) contributes to the intensification of scientific research the aim of which is to improve existing treatment. It is given the data about the state of intestinal microbiota in 64 patients with type 2 DM and NAFLD, 26 patients with type 2 DM and 28--with NAFLD. The research revealed significant changes in microbiota composition in patients with type 2 DM combined with NAFLD. Decompensated dysbiosis was registered in 71.9% of patients in this group which manifested in increased quantitative indicators of transient microflora crop with pathogenic characteristics and lack of microflora with protective characteristics.

[Efficacy of two-level infrainguinal reconstructions in treatment of chronic critical lower limb ischaemia].

AIM: to determine the scope of infrainguinal revascularization of the limb in patients with multilevel lesions of arteries in chronic critical lower limb ischaemia (CCLLI). MATERIAL AND METHODS: A retrospective analysis of graft patency and limb salvage included a total of 76 patients undergoing a total of 78 bypass procedures consisting of: 1) two-level infrainguinal reconstructions (n = 35), 2) femoral-tibial (n = 36) and femoralplantar (n 7) bypass procedures. All patients had an isolated segment, of the popliteal artery in a combination with bifurcation arterial occlusive disease. Autovenous reversed retrograde and orthotopic in (situ vein grafts were used. All patients underwent intraoperative haemodynamic measurements. Graft patency was assessed by Doppler monitoring. The two groups studied were compared by demographic features and risk factors by means of the Student's and chi-squared tests. RESULTS: Life-table analysis showed demonstrated that two-level infrainguinal reconstructions provided better primary 3-year patency (76.2%) as compared with femoral-tibia! and plantar bypasses (60.4%, p<0.05). Intraoperative mortality occurred in 2 patients (2.5%). Early and mid-term thromboses appeared to be most frequently encountered in the group of femoral-tibial, and plantar reconstructions (18.6% vs 11.4%, p<0.38 and 30.8% vs 10.3%, p=0.04, respectively). CONCLUSION: Two-level infrainguinal arterial reconstruction in patients with CCLLI is an acceptable procedure alternative providing better graft patency higher limb salvage rate as compared with femoral-tibial or femoroplantar bypass.

[Dynamics of interferon production during different phases of the pathological process in children with acute pneumonia and relapsing bronchitis]. / Dynamika interferonoutvorennia v rizni fazy patolohichnoho protsesu u ditei, khvorykh na hostry pnevmonoiiu ta retsydyvuiuchyi bronkhit.

With the purpose of gaining further insight into regularities of changes that take place in indices for the interferon status in children with acute pneumonia and current bronchitis depending on the phase of the pathological process, 112 children were examined in whom the level of serum interferon was measured together with production of alpha- and gamma-interferon by leucocytes of the peripheral blood in vitro. It is shown that in the examined patients with acute pneumonia and relapsing bronchitis in the acute period and during the phase of reparation there are differences in functioning of indices for the system of interferon.

Non-Debye screening of a surface charge and a bulk-ion-controlled anchoring transition in a nematic liquid crystal.

We study the anchoring mechanism due to substrate-adsorbed ions by examining a related anchoring transition. An analytical solution to the Poisson equation shows that, as their number suffices for a non-negligible anchoring contribution, the surface field is screened over some characteristic microscopic distance. It is shown both theoretically and experimentally that the critical temperature of the transition can be controlled by bulk ion density through its relation to the density of adsorbed ions.

[Experimental substantiation of cryodenervation method for anesthesia in patients with malignant tumors]. / Eksperimental'ne obhruntuvannia metodu kriodenervatsii z metoiu zneboliuvannia u khvorykh z zloiakisnym novoutvohenniam.

Results of investigations for more profound studying of different parameters of the cryogenic influence on neural fibers are adduced. According to the histological investigations the nerves cryodestruction at -50 degrees C temperature and lower caused the changes appearance with a gradual deepening of destructive changes under the influence of the more lower temperature.

[Escherichia coli ribosomes having peptidyl-tRNA and deacylated tRNA at the A- and P-sites, respectively, may not be competent in translocation]. / Rybosomy Escherichia coli, shcho maiut' u A- ta P-saitakh vidpovidn'o peptydyl-tRNK ta deatsyl'ovanu tRNK, mozhut' buty nekompetentni u transl'okatsiï.

Ribosomes can have two states at 0 degree C: competent and noncompetent in translocation. In both states poly(U)-programmed ribosomes bind phenylalanyl-tRNA to A and P sites and form peptide bond. Elongation factor G promotes fast translocation in competent ribosomes and makes them noncompetent ones. Initial correlation between competent and noncompetent ribosomes is 2:1. Addition of deacylated tRNA does not influence phenomenon described as well as thermal reactivation of the ribosomes before beginning of the experiments. The possibility of deacylated tRNA translocation is shown. The translocation does not occurred provided that at least one of the ribosome sites is filled with shortened tRNA analog (tRNA with truncated CCA-end or tRNA anticodon arm).

[The restriction fragment length polymorphism of the DNA loci of human chromosome 7]. / Polimorfizm dliny restriktsionnykh fragmentov DNK-lokusov khromosomy 7 cheloveka.

The results of comparative RFLP analysis in some DNA loci of chromosome 7 in the populations of different Ukrainian regions are presented. Significant differences in RFLP-genotype distributions among regional populations are found. The role of different genetical processes which take place in the populations of different regions of the Ukraine is under discussion.

[Surgical treatment of combined occlusions of the aorto-femoral and femoro-popliteal vascular segments in patients with severe ischemia of the lower extremities]. / Khirurgicheskoe lechenie sochetannoi okkliuzii sosudov aorto- bedrennogo i bedrenno-podkolennogo segmentov u bol'nykh s tiazheloi ishemiei nizhnikh konechnostei.

The experience with surgical treatment of 107 patients with severe ischemia of the lower extremities, including 52 with associated lesion of the vessels of the aorto-femoral and femoro-popliteal segments, is summarized. A complex of preoperative and intraoperative assessment of regional hemodynamics was used. This permitted to avoid the amputation of an extremity in 86.6% of the patients.