On charged impurity structures in liquid helium

The thermoluminescence spectra of impurity-helium condensates (IHC) submerged in superfluid helium have been observed for the first time. Thermoluminescence of impurity-helium condensates submerged in superfluid helium is explained by neutralization reactions occurring in impurity nanoclusters. Optical spectra of excited products of neutralization reactions between nitrogen cations and thermoactivated electrons were rather different from the spectra observed at higher temperatures, when the luminescence due to nitrogen atom recombination dominates. New results on current detection during the IHC destruction are presented. Two different mechanisms of nanocluster charging are proposed to describe the phenomena observed during preparation and warmup of IHC samples in bulk superfluid helium, and destruction of IHC samples out of liquid helium

Dynamics of thermoluminescence spectra of impurity– helium condensates containing stabilized nitrogen and oxygen atoms

The results of investigations of thermoluminescence dynamics during destruction of neon–helium and krypton–helium condensates containing stabilized nitrogen and oxygen atoms are presented. Spectra of the thermoluminescence of a krypton–helium condensate contained bands of N and O atoms and NO molecules. The intensities of the bands in these spectra were found to increase simultaneously during destruction processes in the temperature range 1.5–15 K. Observation of the NO molecules provides clear evidence for chemical reactions in the nanoclusters comprising the sample at low temperatures. Destruction of neon–helium samples occurred in two stages. During the first stage the α-group of N atoms surrounded by Ne and N₂ molecules dominated the spectra. During the second stage, the spectra contained intense bands of N and O atoms stabilized in a molecular nitrogen matrix. The unusual characteristics of the thermoluminescence spectra were observed, and their changes were explained in terms of the shell structure of impurity nanoclusters which comprised the impurity–helium condensates

Optical spectroscopy and current detection during warm-up and destruction of impurity–helium condensates

New experimental results on detection of optical spectra and ion currents during destruction of impurity–helium condensates (IHCs) have been obtained. It is shown that emission during IHC sample destruction is accompanied by current pulses, pressure peaks and temperature changes. The molecular bands of excimer molecules XeO* are assigned to molecules stabilized in films of molecular nitrogen covering the heavier cores of impurity clusters which form impurity–helium condensates

On charged impurity structures in liquid helium

The thermoluminescence spectra of impurity-helium condensates (IHC) submerged in superfluid helium have been observed for the first time. Thermoluminescence of impurity-helium condensates submerged in superfluid helium is explained by neutralization reactions occurring in impurity nanoclusters. Optical spectra of excited products of neutralization reactions between nitrogen cations and thermoactivated electrons were rather different from the spectra observed at higher temperatures, when the luminescence due to nitrogen atom recombination dominates. New results on current detection during the IHC destruction are presented. Two different mechanisms of nanocluster charging are proposed to describe the phenomena observed during preparation and warmup of IHC samples in bulk superfluid helium, and destruction of IHC samples out of liquid helium

Comparative study of thermostimulated luminescence and electron emission of nitrogen nanoclusters and films

We have studied thermostimulated luminenscence and electron emission of nitrogen films and nanoclusters containing atomic nitrogen free radicals. Thermostimulated electron emission from N₂ nanoclusters was ob-served for the first time. Thermostimulated luminescence spectra obtained during N₂–He sample destruction are similar to those detected from N₂ films pre-irradiated by an electron beam. This similarity reveals common mechanisms of energy transfer and relaxation. The correlation of the luminescence intensity and the electron cur-rent in both systems points to the important role of ionic species in relaxation cascades. A sublimation of solid helium shells isolating nitrogen nanoclusters is a trigger for the initiation of thermostimulated luminescence and electron emission in these nitrogen–helium condensates

Мониторинг кардиотоксического действия бедаквилина у детей старшего возраста и подростков с множественной и широкой лекарственной устойчивостью возбудителя

The objective: to evaluate expanded monitoring of cardiovascular disorders in older children and adolescents with multiple drug resistant tuberculosis receiving bedaquiline (Bq) as a part of anti-tuberculosis therapy.Subjects and Methods: A cohort retrospective-prospective study (2015-2021) was conducted, which included 36 patients aged 13-17 years old who received Bq. The prospective part included 19 patients (Main Group), they underwent extended monitoring (EM) of cardiotoxic reactions; this extended monitoring program was developed in Central Tuberculosis Research Institute. The retrospective part included 17 patients (Control Group), in whom cardiotoxic reactions were assessed using standard monitoring recommended by the Russian Society of Phthisiologists at that time. The relationship between the studied risk factor (monitoring by standard ECG) and the outcome (Bq discontinuation) was assessed using the Pearson χ2 test.Results. Prolongation of the QTc interval > 0.440 ms was noted in 17.6% of cases in Control Group and it was regarded as a cardiotoxic effect of Bq, the drug was discontinued. In Main Group, prolongation was noted in 47.3% of cases which was considered a functional disorder of the cardiovascular system according to EM, the drug was not discontinued, χ2 = 3.896; p = 0.049. EM can be used in older children and adolescents with multiple drug resistant respiratory tuberculosis, which will make it possible to safely include Bq to chemotherapy regimens.Цель исследования: оценить расширенный мониторинг сердечно-сосудистых нарушений у детей старшего возраста и подростков, больных туберкулезом с МЛУ МБТ, получающих бедаквилин (Bq) в составе противотуберкулезной терапии.Материалы и методы: проведено когортное ретроспективно-проспективное исследование (2015-2021 гг.), в которое включены 36 пациентов 13-17 лет, получавшие Bq. В проспективную часть вошли 19 пациентов (основная группа), им проводился расширенный мониторинг (РМ) кардиотоксических реакций, разработанный на базе ФГБНУ «ЦНИИТ»; в  ретроспективную часть включены 17 пациентов (контрольная группа), у которых кардиотоксические реакции оценивались с помощью стандартного мониторинга, рекомендованного РОФ в тот период времени. Взаимосвязь между изучаемым фактором риска (проведение мониторинга по стандартной ЭКГ) и исходом (отмена Bq) оценивали с помощью критерия χ2 Пирсона.Результаты исследования. Удлинение интервала QTс > 0,440 мс отмечено в 17,6% случаев в контрольной группе и расценено, как кардиотоксическое действие Bq, препарат был отменен. В основной группе удлинение отмечено в 47,3% случаев, расценено с помощью РМ как функциональное нарушение со стороны сердечно-сосудистой системы, препарат был не отменен χ2 = 3,896; р = 0,049. РМ может быть использован у детей старшего возраста и подростков, больных туберкулёзом органов дыхания с МЛУ МБТ, что позволит безопасно включать Bq в режимы химиотерапии

Studies of charging mechanisms in impurity-helium condensates by means of impedance spectroscopy and current spectroscopy

A new simple experimental technique has been elaborated to test applicability of impedance spectroscopy for studying processes during destruction of impurity-helium condensates. Combination of methods of optical spectroscopy, impedance spectroscopy and current spectroscopy to study the destruction processes of impurityhelium condensates has been applied for the first time. Experimental data have demonstrated a rather good sensitivity of the technique and proved formation of charged clusters during a destruction stage of impurity-helium condensates.Просту експериментальну методику розроблено та успішно випробувано для використання можливостей спектроскопії імпедансу при дослідженні процесів на стадії руйнування зразків домішково-гелієвих конденсатів. Вперше використано комбінацію методів спектроскопії імпедансу, струмової спектроскопії та оптичної спектроскопії для дослідження руйнування домішково-гелієвих конденсатів. Отримані результати показали високу чутливість нової методики та підтвердили появу зарядів (заряджених нанокластерів) на стадії руйнування домішково-гелієвих конденсатів. Ключові слова: нанокластери, доміПростая экспериментальная методика разработана и успешно опробована для использования возможностей спектроскопии импеданса при исследовании процессов на стадии разрушения образцов примесь-гелиевых конденсатов. Впервые использована комбинация методов спектроскопии импеданса, токовой спектроскопии и оптической спектроскопии для исследования разрушения примесь-гелиевых конденсатов. Полученные результаты показали высокую чувствительность новой методики и подтвердили появление зарядов (заряженных нанокластеров) на стадии разрушения примесьгелиевых конденсатов