Properties of discrete breathers in graphane from ab initio simulations

A density functional theory (DFT) study of the discrete breathers (DBs) in graphane (fully hydrogenated graphene) was performed. To the best of our knowledge, this is the first demonstration of the existence of DBs in a crystalline body from the first-principle simulations. It is found that the DB is a robust, highly localized vibrational mode with one hydrogen atom oscillating with a large amplitude along the direction normal to the graphane plane with all neighboring atoms having much smaller vibration amplitudes. DB frequency decreases with increase in its amplitude, and it can take any value within the phonon gap and can even enter the low-frequency phonon band. The concept of DB is then used to propose an explanation to the recent experimental results on the nontrivial kinetics of graphane dehydrogenation at elevated temperatures.Comment: 20.07.14 Submitted to PhysRev

Oxidation of n-С5-С8 hydrocarbons and cyclohexane in a reactor with barrier discharge. P. 2. Simulating cyclohexane oxidation reaction

Numerical model of hydrocarbon oxidation kinetics in a reactor with barrier discharge has been proposed by the example of cyclohexane oxidation reaction. The results of calculations with the use of barrier discharge surface model showed that electron energy and other discharge characteristics in pure oxygen and in the mixture of oxygen with cyclohexane vapors slightly differ that allowed using a simplified model of homogeneous discharge for simulating cyclohexane oxidation reaction. The results of calculation showed good fit with the experimental dat

The "Horizon-T" Experiment: Extensive Air Showers Detection

Horizon-T is an innovative detector system constructed to study Extensive Air Showers (EAS) in the energy range above 10^16 eV coming from a wide range of zenith angles (0 - 85 degrees). The system is located at Tien Shan high-altitude Science Station of Lebedev Physical Institute of the Russian Academy of Sciences at approximately 3340 meters above the sea level. It consists of eight charged particle detection points separated by the distance up to one kilometer as well as optical detector subsystem to view the Vavilov-Cerenkov light from the EAS. The time resolution of charged particles and Vavilov-Cerenkov light photons passage of the detector system is a few ns. This level of resolution allows conducting research of atmospheric development of individual EAS.Comment: Initial technical note for Horizon-T experiment, updated with recent detector upgrades, 11/2016. Updated 12/2017 with minor edits. Large upgrade will be in another articl

НЕРЕГУЛЯРНАЯ КОММУТАЦИЯ В СИСТЕМЕ ЭЛЕКТРОМЕХАНИЧЕСКОГО ПРЕОБРАЗОВАНИЯ ЭНЕРГИИ ИНЕРЦИОННОГО НАКОПИТЕЛЯ

The algorithm and the mathematical model of the irregular switching process in electromechanical energy conversion system of the inertial storage device in the electric rolling stock traction drive are given, as well quantification the irregular switching through simulation modeling is performed. References 2, figures 4.Приводятся алгоритм и математическая модель процесса нерегулярной коммутации в системе электромеханического преобразования энергии инерционного накопителя в составе тягового привода электроподвижного состава, а также проводится количественная оценка нерегулярной коммутации путем имитационного моделирования. Библ. 2, рис. 4

The research of uranium monoxide-oxide dissolution process in nitric acid

The kinetics of concentrates of uranium monoxide-oxide dissolution process by nitric acid solutions of 5...9 mole/l in the range of 11...90 °C has been studied. It is stated that initial nitric acid concentration increasing results in some uranium dissolution degree increasing only at the first process stage. Temperature increasing significantly raises uranium dissolution degree at the first stage as well. Uranium dissolution degree increases for all studied temperatures with increasing of the process period. The main feature of the studied process is that while dissolving uranium monoxide-oxide the behavior of iron, molybdenum, silicon additives is adequate to that of uranium. The equation of the reducing sphere describes the uranium leaching process from its nitric acid concentrate

Технология коронарного стентирования и роль воспаления в атерогенезе: проблемы и перспективы

 Coronary artery disease (CAD) remains one of the leading causes of death in developed industrial countries. Timely and effective medical care for CAD patients depends on availability and application of endovascular methods for CAD treatment. Percutaneous coronary intervention (PCI) using drug- eluting stents allows to achieve good clinical results even in most severe patients. The issues of personalized invasive treatment for patients with chronic coronary syndrome and optimal prevention of recurrent clinical events in survivors of acute coronary syndrome and PCI remain relevant.One of most important and unresolved problems in the pathophysiology of CAD is assessment of the nature of the inflammatory reaction that develops in the coronary vessels and myocardium in response to ischemic damage and PCI. Clinical studies focused on exploring correlation between the pro-inflammatory parameters of the patient’s status and the rate of secondary adverse events and aimed at revealing triggers of systemic and local inflammation are of great interest. Such a trigger could be the intestinal endotoxin (ET) which is capable of inducing systemic inflammation and, therefore, plays a significant role in the atherogenesis. A relationship between the endotoxin and cytokine system parameters should be investigated to develop a therapeutic concept for supporting CAD patients, including individuals after PCI. Parameters of systemic endotoxemia could be used as additional factors  in developing the biomarker-based approach to identify patients with active inflammation or fibrosis. This could result in development of specific therapy aimed at suppressing pro-inflammatory mediators and protecting the heart from inflammation.  Ишемическая болезнь сердца (ИБС) остается одной из ведущих причин смертности в развитых индустриальных странах. Своевременная эффективная помощь данному контингенту больных зависит от доступности и эффективности применения эндоваскулярных методов лечения ИБС. Чрескожное коронарное вмешательство (ЧКВ) с применением стентов с лекарственным покрытием позволяет добиваться хороших клинических результатов даже у самых тяжелых групп пациентов. Остаются  актуальными вопросы персонализации планового  инвазивного лечения пациентов с хроническим  коронарным синдромом, а также оптимальной вторичной профилактики повторных клинических событий у пациентов, благополучно переживших острый коронарный синдром и ЧКВ.Одной из важнейших и неразрешенных проблем в  патофизиологии ИБС является оценка характера  воспалительной реакции, развивающейся в венечных  сосудах и миокарде в ответ на ишемическое повреждение и ЧКВ. Представляют интерес клинические исследования, направленные на изучение корреляции показателей провоспалительного статуса пациентов с частотой развития  повторных неблагоприятных клинических событий с целью выявления индуктора системного и местного (в стенте)  воспаления. Вероятным кандидатом является кишечный  эндотоксин, способный индуцировать системное  воспаление и таким образом играющий существенную роль в атерогенезе. Необходимы исследования взаимодействия  параметров эндотоксиновой и цитокиновой систем для  выработки терапевтической концепции поддержки больных  ИБС, в том числе после проведения процедуры стентирования коронарных артерий. Использование  показателей системной эндотоксинемии в прогнозе течения заболевания может быть дополнительным фактором для выработки подходов, основанных на биомаркерах для  идентификации больных с активным воспалением  или  фиброзом, что привело бы к разработке специфической  терапии, направленной на подавление провоспалительных  медиаторов и защиту сердца от воспалительного  повреждения.

Macrophage and tumor cell responses to repetitive pulsed X-ray radiation

To study a response of tumor cells and macrophages to the repetitive pulsed low-dose X-ray radiation. Methods. Tumor growth and lung metastasis of mice with an injected Lewis lung carcinoma were analysed, using C57Bl6. Monocytes were isolated from a human blood, using CD14+ magnetic beads. IL6, IL1-betta, and TNF-alpha were determined by ELISA. For macrophage phenotyping, a confocal microscopy was applied. "Sinus-150" was used for the generation of pulsed X-ray radiation (the absorbed dose was below 0.1 Gy, the pulse repetition frequency was 10 pulse/sec). The irradiation of mice by 0.1 Gy pulsed X-rays significantly inhibited the growth of primary tumor and reduced the number of metastatic colonies in the lung. Furthermore, the changes in macrophage phenotype and cytokine secretion were observed after repetitive pulsed X-ray radiation. Conclusion. Macrophages and tumor cells had a different response to a low-dose pulsed X-ray radiation. An activation of the immune system through changes of a macrophage phenotype can result in a significant antitumor effect of the low-dose repetitive pulsed X-ray radiation