Reversible Band Gap Engineering in Carbon Nanotubes by Radial Deformation

We present a systematic analysis of the effect of radial deformation on the atomic and electronic structure of zigzag and armchair single wall carbon nanotubes using the first principle plane wave method. The nanotubes were deformed by applying a radial strain, which distorts the circular cross section to an elliptical one. The atomic structure of the nanotubes under this strain are fully optimized, and the electronic structure is calculated self-consistently to determine the response of individual bands to the radial deformation. The band gap of the insulating tube is closed and eventually an insulator-metal transition sets in by the radial strain which is in the elastic range. Using this property a multiple quantum well structure with tunable and reversible electronic structure is formed on an individual nanotube and its band-lineup is determined from first-principles. The elastic energy due to the radial deformation and elastic constants are calculated and compared with classical theories.Comment: To be appear in Phys. Rev. B, Apr 15, 200

Possibilities of interferon induced neutropenia treatment for patients with chronic hepatitis С

The aim of our study was to estimate the effectiveness of Russian medicament Licopid to treat interferon-induced neutropenia in patients with chronic hepatitis C. The study included 21 patients with moderate and severe neutropenia during standard antiviral therapy. Genotype 1 HCV were 52.4% of patients, patients with non-genotype 1 was 47.6%. Pegylated IFN-a and ribavirin received 12 patients, standard IFN-a and ribavirin - 9 patients. Likopid was administered at a dosage of 20 mg per day for 20 days. In all patients during treatment with Likopid there was clinically meaningful and reliable growth the number of peripheral blood neutrophils to the 10th and/or 20th day of therapy. In most patients, the positive effect lasted for at least 30 days after discontinuation of the Likopid. We found that Likopid is effective regardless of genotype HCV, baseline viral load and the type of interferon. During treatment with Licopid patients had no need to take modify doses of antiviral medicine.Целью исследования явилась оценка эффективности применения отечественного препарата Ликопид, для лечения интерферон-индуцированной нейтропении у больных хроническим вирусным гепатитом С. В исследование был включен 21 пациент с нейтропенией средней и тяжелой степени на фоне стандартной противовирусной терапии. Генотип 1 вируса гепатита С имели 52,4% больных, пациенты с не 1 генотипом составили 47,6%. Лечение пегилированным ИФН-а и рибавирином получали 12 пациентов, стандартным ИФН-α и рибавирином - 9 человек. Ликопид назначался в дозировке 20 мг в сутки в течение 20 дней. У всех пациентов, на фоне лечения Ликопидом наблюдался клинически значимый и достоверный рост числа нейтрофилов периферической крови к 10-му и/или 20-му дню терапии. У большинства больных положительный эффект сохранялся по меньшей мере в течение 30 дней после отмены Ликопида. Нами установлено, что Ликопид одинаково эффективно действует у пациентов не зависимо от генотипа вируса, исходной вирусной нагрузки и типа применяемого интерферона. Во время его применения не потребовалась модификация дозы интерферона-α

New composites of betulin esters with arabinogalactan as highly potent anti-cancer agents

<p>Betulin and its esters are the natural compounds with high <i>in vitro</i> cytotoxicity toward many cancer cells. However, the poor water solubility of these compounds has limited their applications. We prepared new composites of betulin esters using two methods, namely ball-milling of the mixtures of betulin esters with arabinogalactan and preparation of thin films of these mixtures by evaporating the aqueous solutions. These composites revealed higher water solubility as compared with the initial substances without losing the structural integrity and functionality. As a result, the new composites have shown much higher inhibitory effects against different cancer cell lines such as Ehrlich ascites carcinoma cells and lung carcinoma cells (A549) in comparison with the initial substances. The cell viability studies based on Annexin V and Propidium iodide probes have confirmed the high proapoptotic effect of betulin ester derivatives against cancer cells.</p

Inside NAV. The role of organizational culture in internal co-operation and merging of NAV offices.

Deflection due to planar channeling and volume reflection in short bent silicon crystals was observed for the first time for 150 GeV/c negative particles, π− mesons, at one of the secondary beams of the CERN SPS. The deflection efficiency was about 30% for channeling and higher than 80% for volume reflection. Volume reflection occurs, in spite of the attractive character of the forces acting between the particles and the crystal planes, in a wide angular range of the crystal orientations determined by the crystal bend angle