Photon assisted tunneling in pairs of silicon donors

Shallow donors in silicon are favorable candidates for the implementation of solid-state quantum computer architectures because of the promising combination of atomiclike coherence properties and scalability from the semiconductor manufacturing industry. Quantum processing schemes require (among other things) controlled information transfer for readout. Here we demonstrate controlled electron tunneling at 10 K from P to Sb impurities and vice versa with the assistance of resonant terahertz photons

Velocity dependent interactions and a new sum rule in bcc He

Recent neutron scattering experiments [PRL,{\bf 88},p.195301 (2002)] on solid $^4$He, discovered a new optic-like mode in the bcc phase. This excitation was predicted by a recently proposed model that describes the correlated atomic zero-point motion in bcc Helium in terms of dynamic electric dipole moments. Modulations of the relative phase of these dipoles between different atoms describes the anomalously soft T$_1$(110) phonon and two new optic-like modes, one of which was recently found in the neutron scattering experiments. In this work we show that the correlated dipolar interactions can be written as a velocity dependent interaction. This then results in a modified f-sum rule for the T$_1$(110) phonon, in good agreement with the recent experimental data.Comment: 5 pages, 3 figure

Experimental study on grooved Si and Ge crystals for Laue lens application

An experimental study on the method of indentations for bent crystals to realize a hard X-ray Laue lens has been done. We tested the diffraction properties of indented Si and Ge crystalline plates at European Synchrotron Radiation Facility (Grenoble, France). The samples were analyzed by diffraction of their (111) planes with hard X-rays from 150 to 600 keV. Crystals have shown significantly high diffraction efficiency, i.e. a Si crystal has exhibited up to 80% at 300 keV. A Ge crystal has confirmed the observation for a Si one, though the diffraction efficiency was about 60%. In both cases rocking curves showed flat-toped rectangular shapes, which demonstrates that the method of indentations evenly bends the crystals. Moreover, measured angular spread was always very close to the morphological curvature of the sample under investigation, showing that this method offers high reproducibility and, thus, easy control of diffraction properties of the crystals

The effect of short-term antiorthostatic hypokinesia on central and intracardiac hemodynamics and metabolism of a healthy person

The right parts of the heart and the radial artery were catheterized in healthy male volunteers before and 5 days after strict bedrest in antiorthostatic position of the body (-4.5 deg). After immobilization, most values of central circulation showed no essential changes; the only exceptions were indicates characterizing the inotropic myocardial condition. A shift in the direction of acidosis of a mixed character was noted in mixed venous blood, the beta lipoprotein content increased. A decrease in the arteriovenous difference in oxygen was encountered in blood draining from the heart (from the coronary sinus)

Бронхиальная астма, свистящие хрипы, флаттер. Возможные взаимоотношения

Wheezing is the most common clinical sign and one of the key diagnostic criteria of asthma. Pathophysiology of wheezing is not fully recognized. A theory of hemodynamic flatter is widely adopted. Effects of vibration are actively investigated in patients with snore and obstructive sleep apnea. Vibration can contribute to the upper airway inflammation and endothelial dysfunction in snoring patients. Therefore, the flatter (vibration) effect could be the key mechanism of wheezing in asthma patients and could promote similar changes in the lower airway microvasculature. Recently, CPAP therapy has been shown to reduce asthma symptoms and bronchial hyperresponsiveness and acts as a mechanical bronchodilator is patients with asthma without sleepassociated breathing disorders.В статье рассматриваются взаимоотношения свистящих хрипов (wheezing) и вибрации (флаттера) у больных бронхиальной астмой (БА). Приводятся сведения о влиянии вибрации на патофизиологические изменениях верхних дыхательных путей в эксперименте. Высказано предположение, что вибрация (флаттер) как один из ключевых механизмов свистящих хрипов может способствовать развитию воспалительных изменений, эндотелиальной дисфункции микроциркуляторного русла в нижних отделах дыхательных путей у больных БА

Бронхиальная астма и функциональные нарушения дыхания: синдром «бронхиальная астма-плюс»

Comorbidity in asthma encompasses different respiratory system disorders including dysfunctional breathing and vocal cord dysfunction. Such comorbidity is referred to as "asthma-plus" syndrome. This condition is not fully investigated resulting in its late diagnosis and inadequate treatment. This article is a review of clinical signs, differential diagnosis, and key issues of management of "asthma-plus" syndrome.К коморбидным состояниям у больных бронхиальной астмой (БА) относится развитие функциональных нарушений дыхания (ФНД), включающих дисфункциональное дыхание и дисфункцию вокальных хорд. Сочетание БА и ФНД в настоящее время получило наименование «синдром бронхиальная астма-плюс». Однако проблемы ФНД остаются недостаточно изученными, что обусловливает их позднюю диагностику и неадекватную терапию. В настоящем обзоре представлены клинические особенности, актуальные вопросы дифференциальной диагностики, указаны существующие принципы менеджмента ФНД