GAMMA-RAY SPECTROMETRY OF HOT PLASMAS

Gamma-ray spectrometry provides diagnostics of fast ion behavior in plasmas of large tokamaks. Information acquiring with the gamma-ray diagnostics gives possibility to identify and distinguish simultaneously presence of fast alpha-particles and other ions He), to obtain its relative densities and also to perform tomographic radial profile reconstruction of the gammaemission sources

Ultrafast hybrid nanocomposite scintillators: A review

In recent years, demand for scintillation detectors with high time resolution (better than 100 ps) has emerged in high-energy physics and medical imaging applications. In particular, time of flight positron emission tomography (TOF-PET) can greatly benefit from increasing time resolution of scintillators, which leads to the increase of signal-to-noise ratio, decrease of patient dose, and achievement of the superior spatial resolution of PET images. Currently, extensive research of various types of materials is carried out to achieve the best time resolution. In this review, the recent progress of various approaches is summarized and scintillation compounds with the best temporal characteristics are first reviewed. The review presents the physical processes causing fast luminescence in inorganic and organic materials. Special attention is paid to nanocomposites which belong to a new perspective class of scintillating materials, consisting of a plastic matrix, inorganic nanocrystalline fillers, and organic or inorganic luminescence activators and shifters. The main features and functions of all parts of existing and prospective nanocomposite scintillators are also discussed. A number of currently created and investigated nanocomposite materials with various compounds and structures are reviewed. © 2021 Elsevier B.V.Eesti Teadusagentuur, ETAg: PRG111, PRG629; European Regional Development Fund, ERDF: 2014-2020.4.01.15–0011, TK141Authors thank Minobrnauki project FEUZ-2020-0059 and Estonian Research Council (grants PRG629 and PRG111 ) for financial support. Authors are also grateful for partial support from the European Regional Development Fund (DoRA Pluss program) and the ERDF funding in Estonia granted to the Center of Excellence TK141 “ Advanced materials and high-technology devices for sustainable energetics, sensorics and nanoelectronics ” (project No. 2014-2020.4.01.15–0011 )

Radioluminescence properties of nanocomposite scintillators with BaF 2 fillers

In this paper, studies of the luminescence properties of nanocrystalline BaF 2 samples synthesized by laser ablation and pulse electron beam evaporation method are presented. The measurements of X-ray excited luminescence (XEL) showed the dependence between luminescence intensity and the shape of the spectrum on the morphology and particle size. Also, studies of X-ray excited luminescence, decay curves and optical transmittance for nanocomposite materials containing BaF 2 nanopowder are presented. Barium fluoride nanopowder, obtained by pulsed electron beam evaporation method is characterized by a lower intensity than the initial microcrystalline powder, but at the same time, XEL spectrum of the nanocomposite material with this nanocrystalline filler is more intense, then that for nanocomposite material with initial powder. © Published under licence by IOP Publishing Ltd

Coherent Cherenkov radiation as an intense THz source

Diffraction and Cherenkov radiation of relativistic electrons from a dielectric target has been proposed as mechanism for production of intense terahertz (THz) radiation. The use of an extremely short high-energy electron beam of a 4th generation light source (X-ray free electron laser) appears to be very promising. A moderate power from the electron beam can be extracted and converted into THz radiation with nearly zero absorption losses. The initial experiment on THz observation will be performed at CLARA/VELA FEL test facility in the UK to demonstrate the principle to a wider community and to develop the radiator prototype. In this paper, we present our theoretical predictions (based on the approach of polarization currents), which provides the basis for interpreting the future experimental measurements. We will also present our hardware design and discuss a plan of the future experiment

Синдром пароксизмальной симпатической гиперактивности (обзор)

Paroxysmal sympathetic hyperactivity (PSH) is one of the complications of acute severe brain injuries (traumatic brain injury, intracranial hemorrhage, ischemia, and posthypoxic conditions) in both adults and children. Its high incidence and severe sequelae including organ dysfunction, infectious complications, impaired blood supply to organs and tissues associate with increased disability and mortality. The choice of effective therapy can be challenging because of multifaceted manifestations, diagnostic difficulties, and lack of a clear understanding of the pathophysiology of PSH. Currently, there are various local and international treatment strategies for PSH.The aim of the review is to summarize clinical and scientific research data on diagnosis and treatment of PSH to aid in the selection of an effective therapy.Material and methods. Web of Science, Scopus and RSCI databases were employed to select 80 sources containing relevant clinical and research data on the subject of this review.Results. The key principles of diagnosis and treatment of paroxysmal sympathetic hyperactivity have been reviewed. The current views on etiology and pathogenesis of paroxysmal sympathetic hyperactivity development were outlined. The clinical data concerning complications and sequelae of paroxysmal sympathetic hyperactivity were analyzed. We conclude the review with a discussion of current methods of the syndrome prevention.Conclusion. Preventing PSH and its adequate and prompt treatment could help avoid the abnormal pathway development following a severe brain injury, reduce its negative consequences and rate of complications, along with the duration of mechanical lung ventilation, patient's stay in ICU, disability and mortality rates. Careful selection of pathogenetic, symptomatic and supportive therapy significantly improves the rehabilitation potential of patients.Одним из осложнений острого тяжелого повреждения мозга (черепно-мозговая травма, внутричерепные кровоизлияния, ишемия, постгипоксические состояния) как у взрослых, так и у детей является развитие синдрома пароксизмальной симпатической гиперактивности (ПСГА). Высокая частота его встречаемости и тяжелые негативные последствия: органная дисфункция, инфекционные осложнения, нарушения трофики органов и тканей, приводят к повышению инвалидизации и смертности. Сложности в подборе эффективной терапии связаны с многообразием симптомов, трудностями диагностики, отсутствием четкого понимания патофизиологии ПСГА. В настоящее время существуют различные зарубежные и отечественные схемы лечения ПСГА.Цель обзора — обобщить данные клинических и научных исследований по диагностике и лечению синдрома ПСГА для облегчения подбора эффективной терапии.Материал. В базах данных Web of Science, Scopus и РИНЦ отобрали 80 источников, содержавших актуальные данные клинических и научных исследований по теме данного обзора.Результаты. Рассмотрели основные принципы диагностики и лечения пароксизмальной симпатической гиперактивности; описали современные представления об этиологии и патогенезе развития пароксизмальной симпатической гиперактивности; привели клинические данные, касающиеся развития осложнений пароксизмальной симпатической гиперактивности; проанализировали клинические последствия и описали современные методы профилактики развития синдрома пароксизмальной симпатической гиперактивности.Заключение. Профилактика развития ПСГА, его адекватное и своевременное лечение позволяют предотвратить формирование патологической доминанты (мы рассматриваем ПСГА именно как одну из патологических доминант, формирующихся при тяжелом повреждении ГМ), уменьшить негативные последствия этого синдрома, снизить число осложнений, длительность ИВЛ и пребывания боль- ного в ОРИТ, инвалидизацию и смертность. Подбор патогенетической, симптоматической, а затем поддерживающей терапии значительно улучшает реабилитационный потенциал пациентов

Effect of self-organization and properties of aqueous disperse systems based on the moss peptide PpCLE2 in a low concentration range on the growth of Arabidopsis thaliana roots

© 2017, Springer Science+Business Media, LLC, part of Springer Nature. It is shown for the first time using a complex of physicochemical methods (dynamic and electrophoretic light scattering, conductometry, pH-metry) that below a threshold concentration of 1.0•10 –7 mol L –1 the disperse phase of the aqueous systems based on moss peptide PpCLE2 undergoes the domain—nanoassociate rearrangement, which affects the nonmonotonic concentration dependences of the specific electrical conductivity and pH and can result in a multidirectional profile of the dependence of the growth of the primary and lateral roots of the Arabidopsis thaliana seed plant in the range of calculated concentrations from 1.0•10 –6 to 1.0•10 –12 mol L –1

Selective Brain Hypothermia in the Comprehensive Rehabilitation of Patients with Chronic Consciousness Disorders

Aim: to evaluate clinical effectiveness of selective hypothermia of cerebral cortex for the recovery of awareness in patients with chronic disorders of consciousness (CDC).   Material and methods. 111 patients with CDC 30 and more days after a cerebral event (ischemic or hemorrhagic stroke, brain injury) were included in the study. Exclusion criteria were anoxic brain injury (sequelae of a prolonged asystole or asphyxia), active sepsis, arrhythmia, baseline hypothermia (body temperature lower than 35.5 °С). Experimental group included 60 patients, of them 39 patients were in a vegetative state (VS), 21 patients exhibited patterns of minimally conscious state (MCS). Control group incluted 51 patients, of them 32 patients were in VS and 19 patients were in MCS. Patients in the experimental group received 10 sessions (120 minutes each) of selective brain hypothermia (SBH) during the 14-days follow-up period. Patients of both groups received standard identical neurological treatment and rehabilitation procedures. Patients in the control group did not undergo brain hypothermia. The induction of SBH involved cooling of the whole surface of the craniocerebral area of scalp using special helmets. The temperature of the internal surface of the helmet was 3–7 °С. Temperature of the frontal lobes of the cortex was monitored with non-invasive microwave radiothermometry, axillary temperature was also registered. The level of consciousness was evaluated using «Coma Recovery Scale-Revised» (CRS-R) scale.   Results. 120-minutes long SBH session reduced the temperature of the frontal lobes of the cerebral cortex by 2.4–3.1 °С with no impact on the axillary temperature. Evaluation using CRS-R revealed improvement in all studied functions (auditory, visual, motor, oromotor, communication, arousal) in patients in the experimental group after 10 SBH sessions. Level of consciousness in patients from the experimental group in VS increased from 4.5 ± 0.33 to 8.7 ± 0.91 points (P < 0.001), for patients in MCS from 11.3 ± 1.0 to 18.2 ± 0.70 (P < 0.001) points. In the control group, scores of patients in VS rose from 4.3 ± 0.37 to 6.8 ± 0.49 (P < 0.001) points with the most significant changes in auditory and visual functions (P<0.001). In the control group of patients in MCS the oromotor function improved (P < 0.05), overall CRS-R scores changed insignificantly from 9.1 ± 0.57 to 10.1 ± 0.86 (P < 0.1). The best outcome (CRS-R > 19 points) was seen in patients from the experimental group [6 in VS (15.4 %) and 8 in MCS (31.8 %)]. In the control group, the best results did not exceed 10 points for the patents in VS, while 4 patients in MCS (21 %) reached 12–16 scores. During 30-day follow-up period of hospitalization after the SBH sessions mortality rate was 10 % (6 patients) in the experimental group and 21.6% (11 patients) in the control group.   Conclusion. Patients with CDC could benefit from serial SBH sessions performed as a part of comprehensive treatment and rehabilitation strategy. We suggest that selective reduction of frontal lobe temperature improves neurogenesis, neuronal regeneration, and neuroplasticity

Disperse aqueous systems based on (S)-lysine in a wide range of concentrations and physiologically important temperatures

© 2017, Springer Science+Business Media, LLC, part of Springer Nature. It was shown for the first time using a complex of physicochemical methods (dynamic and electrophoretic light scattering, nanoparticle tracking analysis, transmission electron and atomic force microscopy, conductometry, pH-metry) that in a temperature range of 25—60 °С (S)-lysine aqueous solutions (1•10 –17 —1•10 –2 mol L –1 ) are disperse systems, where the nature and parameters of the disperse phase change with dilution, which affects the nonmonotonic dependences of the specific conductivity and pH of the system. Nanoassociates hundreds of nanometers in size were found to contain ordered water structures that are responsible for the size and ζ-potential of the disperse phase in the aqueous systems and also participate in the formation of spatially organized systems on the support

NMR metabolic profiling of the liver following administrationof alcohol andthemushroom Ganoderma lucidum in rats

We have evaluated the efficiency of a metabonomic approach to metabolic phenotyping and detection of early metabolic changes under a toxic influence. For this purpose, a metabolic profiling of rat liver was performed with 1H NMR spectroscopy. Rat tissues from animals in three groups were analyzed. Group C consisted of control animals; animals in group A received alcohol repeatedly (15 % ethanol); and animals in group A+ R received alcohol in combination with a hepatoprotective herbal medicine (Reishi, Ganoderma lucidum) repeatedly. Noteworthy, alcohol consumption did not cause pathological changes, but stimulated hepatocyte proliferation. Our data suggest that changes in metabolite concentrations in A represent a typical metabolic response to alcohol consumption, namely decrease in glycine, leucine, isoleucine, valine, choline and lactate content, and increase in TMAO content. Treatment with Reishi (A+ R) had positive effects, in that it restored the levels of glycine, valine and TMAO. Furthermore, increase in NAD, ATP, UTP, succinate, pyranose, and acetate concentrations was observed in A+ R. A correlation was found between the valine, isoleucine, lactate, cho­line, and pyranose content and the num­ber of binuclear hepatocytes. Binuclear hepatocytes indicate proliferative activity, and the concentration of the metabolites participating in the formation of new hepatic cells decreases. Thus, the study of liver tissues by 1H NMR spectroscopy allows for detection of early changes in metabolite concentra­tions following chronic consumption of alcohol at insignificant doses. Consequently, 1H NMR spectro­scopy can serve as a promising approach to detecting alcohol-related liver pathologies and assessing the efficiency of the therapy used