Experimental Research of the Diffraction and Vavilov-Cherenkov Radiation Generation in a Teflon Target

Geometry of Vavilov-Cherekov (VChR) radiation when an electron moves close to a dielectric target is in analogy to diffraction radiation (DR) geometry. In this case we may expect DR generation from the upstream face of the target besides that VChR. The joint observation of these booth types of radiation is very interesting from the pseudo-photon viewpoint, which is applicable for relativistic electrons. Unexpected results obtained in our experiment insist on reflection about nature both DR and VChR. The experiment was performed on the relativistic electron beam of the microtron of Tomsk Polytechnic University.Comment: This article will be published in Journal of Physic

Sub-THz radiation from dielectric capillaries with reflectors

In this report we present experimental investigations of THz radiation generated from a corrugated and a non-corrugated capillary with reflectors, using a femtosecond electron beam of LUCX accelerator at KEK, Japan. We discuss measurements of radiation angular distributions and their comparison with Particle In Cell simulations, and also investigate an off-central propagation of the beam in the capillaries based on experimental measurements and simulations.Comment: 5 pages, 5 figure

New Debris Disks Around Nearby Main Sequence Stars: Impact on The Direct Detection of Planets

Using the MIPS instrument on the Spitzer telescope, we have searched for infrared excesses around a sample of 82 stars, mostly F, G, and K main-sequence field stars, along with a small number of nearby M stars. These stars were selected for their suitability for future observations by a variety of planet-finding techniques. These observations provide information on the asteroidal and cometary material orbiting these stars - data that can be correlated with any planets that may eventually be found. We have found significant excess 70um emission toward 12 stars. Combined with an earlier study, we find an overall 70um excess detection rate of $13 \pm 3$% for mature cool stars. Unlike the trend for planets to be found preferentially toward stars with high metallicity, the incidence of debris disks is uncorrelated with metallicity. By newly identifying 4 of these stars as having weak 24um excesses (fluxes $\sim$10% above the stellar photosphere), we confirm a trend found in earlier studies wherein a weak 24um excess is associated with a strong 70um excess. Interestingly, we find no evidence for debris disks around 23 stars cooler than K1, a result that is bolstered by a lack of excess around any of the 38 K1-M6 stars in 2 companion surveys. One motivation for this study is the fact that strong zodiacal emission can make it hard or impossible to detect planets directly with future observatories like the {\it Terrestrial Planet Finder (TPF)}. The observations reported here exclude a few stars with very high levels of emission, $>$1,000 times the emission of our zodiacal cloud, from direct planet searches. For the remainder of the sample, we set relatively high limits on dust emission from asteroid belt counterparts

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

GC-based chemoprofile of lipophilic compounds in Altaian Ganoderma lucidum sample

The presented data contains information about component composition of lipophilic compounds in Ganoderma lucidum fungal body sample obtained using gas chromatography and subsequent mass spectrometry

The relationship between self-organization and membrane effects of aqueous dispersion systems of the thyroliberin oligopeptide

© 2017, Pleiades Publishing, Ltd. The relationship between rearrangement of the dispersed phase inducing considerable changes in the pH and nonmonotonic concentration dependences of membrane effects in aqueous systems of the endogenous regulatory peptide, thyroliberin (thyrotropin-releasing hormone), in 10 –3 –10 –16 mol/L concentration range was demonstrated for the first time. The membrane structure modification in the 10 –13 –10 –16 mol/L range was found to be due to accumulation of nanoassociates, while the oppositely directed pronounced structural changes in the 10 –6 –10 –12 mol/L range may be associated with the coexistence and rearrangement of dispersed phases of various nature (domains and associates) whose action on membrane lipid components is regulated in this concentration range by the correlated changes in the dispersed phase parameters and pH

Hemozoin "knobs" in Opisthorchis felineus infected liver

Background Hemozoin is the pigment produced by some blood-feeding parasites. It demonstrates high diagnostic and therapeutic potential. In this work the formation of co-called hemozoin “knobs” – the bile duct ectasia filled up by hemozoin pigment - in Opisthorhis felineus infected hamster liver has been observed. Methods The O. felineus infected liver was examined by histological analysis and magnetic resonance imaging (MRI). The pigment hemozoin was identified by Fourier transform infrared spectroscopy and high resolution electrospray ionization mass spectrometry analysis. Hemozoin crystals were characterised by high resolution transmission electron microscopy. Results Hemozoin crystals produced by O. felineus have average length 403 nm and the length-to-width ratio equals 2.0. The regurgitation of hemozoin from parasitic fluke during infection leads to formation of bile duct ectasia. The active release of hemozoin from O. felineus during in vitro incubation has also been evidenced. It has been shown that the hemozoin knobs can be detected by magnetic resonance imaging. Conclusions In the paper for the first time the characterisation of hemozoin pigment extracted from liver fluke O. felineus has been conducted. The role of hemozoin in the modification of immune response by opisthorchiasis is assumed

Clinical case of de novo anaplastic ganglioglioma and current status of the problem

The authors report a rare case of de novo malignant ganglioglioma (WHO grade III) in a 26-year old female. The patient has complained of periodic feeling fear, anxiety, episodes of impaired consciousness with extremity muscle cramps sometimes followed by urination, as well as flashes before eyes. Computed tomography perfusion and magnetic resonance spectroscopy were carried out for differential diagnosis between different types of tumors. Stereotactic biopsy was performed for histological examination. High surgical risk became a contraindication to gross total resection of the tumor. The patient has received radiation therapy (Trilogy linear accelerator) in a total dose of 60 Gy. The tumor shrank significantly. In 7 months, monitoring MRT did not detect further growth of the tumor. The authors have analyzed the case and reviewed the existing literature data regarding gangliogliomas. Taking into account low prevalence of these tumors (0.4-1% of all brain tumors), especially of their malignant forms (3-10% of gangliogliomas), lack of sufficient data regarding prognostic factors, life expectancy, time of recurrence, lack of accurate indications for different methods of treatment (surgery, radiation, chemotherapy), these tumors still need further research that should also involve supplementary neuroimaging techniques and stereotactic biopsy