Single-electron transistor effect in a two-terminal structure

A peculiarity of the single-electron transistor effect makes it possible to observe this effect even in structures lacking a gate electrode altogether. The proposed method can be useful for experimental study of charging effects in structures with an extremely small central island confined between tunnel barriers like a nanometer-sized quantum dot or a macromolecule probed with a tunneling microscope), where it is impossible to provide a gate electrode for control of the tunnel current.Comment: 5 pages, 2 figure

Carbamylated darbepoetin in combination with ethoxydol attenuates doxorubicin-induced cardiomyopathy in rats

Doxorubicin is the drug of choice in the treatment of many malignant neoplasms, but its use is limited due to the risk of developing severe cardiomyopathy. This problem necessitates the prevention, early diagnosis and treatment of cardiomyopath

Influence of Co3+^{3+} spin-state on optical properties of LaCoO3_3 and HoCoO3_3

Optical properties of the isoelectronic compounds LaCoO$_3$ and HoCoO$_3$ has been experimentally and theoretically investigated. We've measured the real $\epsilon_1(\omega)$ and imaginary $\epsilon_2(\omega)$ parts of the dielectric function, reflectance $R(\omega)$ and optical conductivity at room temperature. The shift of the most pronounced spectral features to the high energy region on 0.3 eV associated with larger distortions due to the smaller rare earth ionic radii in HoCoO$_3$ in comparison with LaCoO$_3$ was observed. Also there was found an enhancement of absorption intensity in the range 1.3-2.3 eV in all kinds of spectra in HoCoO$_3$, which can be attributed basing on the results of LDA+U calculations to the different spin-states of Co$^{3+}$ ion in these compounds. The shift of the onset of the absorption from less than 0.1 eV in LaCoO$_3$ to 0.7 eV in HoCoO$_3$ and an absorption intensity enhancement in a narrow spectral range 1.2-2.6 eV in HoCoO$_3$ are clearly seen from the calculated convolution of partial densities of states obtained in the LDA+U approach. Such changes are assumed to be induced by the different Co$^{3+}$ spin-state in these compounds at room temperature.Comment: 10 pages, 3 figure

XANES study of rare-earth valency in LRu4P12 (L = Ce and Pr)

Valency of Ce and Pr in LRu4P12 (L = Ce and Pr) was studied by L2,3-edge x-ray absorption near-edge structure (XANES) spectroscopy. The Ce-L3 XANES spectrum suggests that Ce is mainly trivalent, but the 4f state strongly hybridizes with ligand orbitals. The band gap of CeRu4P12 seems to be formed by strong hybridization of 4f electrons. Pr-L2 XANES spectra indicate that Pr exists in trivalent state over a wide range in temperature, 20 < T < 300 K. We find that the metal-insulator (MI) transition at TMI = 60 K in PrRu4P12 does not originate from Pr valence fluctuation.Comment: 4 page

Мультиспиральная компьютерная томография в ранней диагностике пневмонии, вызванной SARS-CoV-2

The high informative value of chest computed tomography in the diagnosis of pneumonia caused by SARS-CoV-2 is generally recognized, but there is no enough data on the diagnostic capabilities of this method within 5 first days of the clinical manifestations of the disease. The paper presents the results of chest multispiral (multislice) computed tomography (MSCT) of 56 patients with COVID-19 pneumonia in the early days of the disease. The aim of the study was to analyze the semiotics of pathological changes in the lungs in the first days of the onset of clinical symptoms of COVID-19 and to clarify the methodology for conducting MSCT. Methods. The data of chest MSCT of 56 patients with clinical symptoms of a new coronavirus infection SARS-CoV-2 were analyzed. MSCT was carried out in the first 4 – 5 days of the disease. Results. Five variants for the development of the disease were revealed, including atypical, characterized by the prevalence and CT semiotics of lung damage and apparently due to the different response of the patients to SARS-CoV-2 infection. The leading signs of COVID-19 pneumonia in the early stages of the disease were foci of ground glass opacification (GGO), multifocal lesions of the lungs, edema of the interalveolar pulmonary interstitium, which distinguishes it from pneumonia of another etiology. Conclusion. Comparison of MSCT data and the clinical picture of the disease during the first 5 days suggests with high confidence the pneumonia associated with COVID-19. A prerequisite for conducting MSCT in case of suspicion of this type of pneumonia is the implementation of thin 0.5 – 1.5 mm sections, MSCT performance at suspended full inspiration, post-processing of unenhanced tomogram data in MinIP mode.Высокая информативность компьютерной томографии (КТ) органов грудной клетки (ОГК) в диагностике COVID-19-ассоциированной пневмонии общепризнанна, однако данные о диагностических возможностях и особенностях выполнения этого метода в первые 5 суток клинических проявлений заболевания отсутствуют. В работе представлены результаты мультиспиральной КТ (МСКТ) ОГК пациентов (n = 56) с COVID-19-ассоциированой пневмонией в первые 4–5 суток развития симптомов болезни. Целью исследования явилось изучение семиотики патологических изменений в легких в первые дни появления клинических симптомов COVID-19 и описание особенностей методики проведения МСКТ. Материалы и методы. Проанализированы данные МСКТ ОГК пациентов с клинической симптоматикой новой коронавирусной инфекции SARS-CoV-2. МСКТ выполнялась в первые 4–5 суток заболевания. Результаты. Выявлено 5 вариантов развития заболевания, включая атипичный, различавшихся распространенностью и КТ-семиотикой поражения легких и обусловленных, по-видимому, различной реакцией организма пациентов на инфекцию SARS-CoV-2. Ведущими признаками COVID-19-ассоциированной пневмонии в ранние сроки заболевания являлись очаги «матового стекла», мультифокальность поражения легких, отек межальвеолярного легочного интерстиция, в чем и состояли отличия COVID-19-ассоциированной пневмонии от таковой другой этиологии. Заключение. Сопоставление данных МСКТ и клинической картины заболевания в течение первых 5 суток заболевания позволяет с высокой достоверностью предположить наличие пневмонии, ассоциированной с COVID-19. Необходимым условием проведения МСКТ при подозрении на пневмонию данного типа является выполнение тонких (0,5–1,5 мм) срезов, контроль за полнотой вдоха пациента, постпроцессинговая обработка данных нативной томограммы в MinIP-режиме