Detection and Visualization of Minor Irradiation-Induced Changes in Polytetrafluoroethylene (PTFE) by Raman Spectroscopy.

Exposure of polytetrafluoroethylene (PTFE) to argon plasma results in chemical modification of the polymer near the surface. Interestingly, PTFE modification can be induced by the sub-band gap ultraviolet (UV) irradiation. In the latter case, the changes in the chemical structure are very subtle, and they are practically invisible to conventional experimental techniques.

Ballistic edge states in Bismuth nanowires revealed by SQUID interferometry.

The protection against backscattering provided by topology is a striking property. In two-dimensional insulators, a consequence of this topological protection is the ballistic nature of the one-dimensional helical edge states. One demonstration of ballisticity is the quantized Hall conductance.

Fabrication and use of a nanoscale Hall probe for measurements of the magnetic field induced by MFM tips.

Extraordinary Hall effect probes with 160 nm × 160 nm working area were fabricated using photo- and electron-beam lithographic procedures with the aim of direct measurements of MFM cantilever tip magnetic properties. The magnetic field sensitivity of the probes was 35 Ω T(-1). Magnetic induction of the MFM cantilever tips coated by Co and SmCo films was measured with the probes.

Superconductivity in ropes of single-walled carbon nanotubes.

We report measurements on ropes of single-walled carbon nanotubes (SWNT) in low-resistance contact to nonsuperconducting (normal) metallic pads, at low voltage and at temperatures down to 70 mK. In one sample, we find a 2 orders of magnitude resistance drop below 0.55 K, which is destroyed by a magnetic field of the order of 1 T, or by a dc current greater than 2.

Proximity-induced superconductivity in DNA.

Conductivity measurements on double-stranded DNA molecules deposited by a combing process across a submicron slit between rhenium/carbon metallic contacts reveal conduction to be ohmic between room temperature and 1 kelvin. The resistance per molecule is less than 100 kilohm and varies weakly with temperature. Below the superconducting transition temperature (1 kelvin) of the contacts, proximity-induced superconductivity is observed.

Acoustoelectric effects in carbon nanotubes.

We report observations of acoustoelectric effects in carbon nanotubes. We excite sound in &mgr;m long ropes of single walled carbon nanotubes suspended between two metallic contacts by applying radio-frequency electric field. The sound is detected by measuring either the dc resistance of the tubes in a region of strong temperature dependence (in the vicinity of superconducting or metal-insulator transition), or their critical current.

Supercurrents through single-walled carbon nanotubes.

Proximity-induced superconductivity in single-walled carbon nanotubes below 1 kelvin, both in a single tube 1 nanometer in diameter and in crystalline ropes containing about 100 nanotubes, was observed. The samples were suspended between two superconducting electrodes, permitting structural study in a transmission electron microscope. When the resistance of the nanotube junction is sufficiently low, it becomes superconducting and can carry high supercurrents.

[Bronchial asthma in a hyperendemic focus of opisthorchiasis (western Siberia)].

The data obtained on bronchial asthma (BA) occurrence in the hyperendemic opisthorchiasis focus in the western Siberia show BA in it to run a more severe and prognostically unfavourable course against the population from other Siberian regions safer by opisthorchiasis. The latter adapted to hepatobiliary system negatively affects the bronchi and lungs due to the involvement of eosinophilic and immunocomplex mechanisms damaging BA patients' shock organ. By means of additional antigenic stimulus, opisthorchiasis sensitization changes BA clinical manifestations and immunological manifestations status of BA patients dictating the necessity of immunological correction.

[Analysis of trace elements and crystalline formations in the sputum in bronchial asthma].

The content of sputum trace elements was investigated in 12 patients with bronchial asthma (BA). The presence of Na, K, Ca, P, Mg, Si, Sn, Fe, Mn, Cu, Ti, Ag, Al, V, B was revealed. The absence of Zn and high levels of Ca and Sn were observed.

[Bronchial asthma and arterial hypertension].

Study of the clinical data concerning patients suffering from bronchial asthma and analysis of the autopsy data allow the conclusion about the presence of a pathogenetically validated symptomatic arterial hypertension including its drug patterns. The increased number of cases of bronchial asthma and arterial hypertension constellation attests to a considerable unbalance of the autonomous nervous system, alterations of the sympathoadrenal effects in such patients, which makes the clinical picture and course of modern bronchial asthma more complicated. The pathogenetic approach to the treatment of such patients characterized by hypersensitivity to the environmental factors, stress situations and to drugs which stimulate the sympathoadrenal system will permit one to avoid diagnostic, deontological errors, to choose sound therapy including measures aimed at preventing arterial hypertension itself.