Scintillation proportional Xe counter with WLS fiber readout for low-energy X-rays

A gas Xe based scintillation proportional counter with cylindrical geometry and wavelength shifting (WLS) fiber readout for X-rays of energy 0.5 - 100 keV is proposed. With such a design large sizes and sensitive area of the counter with a fairly well uniformity is possible. The counter could be used for "dark matter" search and neutrino magnetic moment measurement and for detection of small amounts or traces of radioactive elements in substances or environment.Comment: LaTeX 4 pages, 3 figures in eps, Submitted to NI

Effect of Intraoperative Propofol-Induced Sedation on the Neurotransmitter Levels (Pilot Study)

The aim of the study was to determine the changes in the levels of various neurotransmitters depending on the depth of propofol-induced sedation.Material and methods. Twenty-four patients were included in a prospective, simple blinded study. All patients underwent elective orthopedic intervention with subarachnoid anesthesia and moderate (group 1, n=12) or deep (group 2, n=12) propofol-induced sedation. Peripheral blood sampling for measurement of neurotransmitter levels was performed before regional blockade (Stage 1), 35–40 min after the start of sedation (Stage 2), and 10–15 min after sedation was terminated and consciousness was recovered (Stage 3).Results. Deep propofol-induced sedation resulted in a decrease in norepinephrine level at stages 2 and 3. Under moderate sedation, its level decreased at Stage 2 and returned to baseline after restoration of consciousness. The initial concentration of norepinephrine (Stage 1) was higher in Group 2.Conclusion. Propofol-induced sedation resulted in reduced level of the main stress hormone, which suggests its stabilizing effect on autonomic nervous system

Structure, bonding and morphology of hydrothermally synthesised xonotlite

The authors have systematically investigated the role of synthesis conditions upon the structure and morphology of xonotlite. Starting with a mechanochemically prepared, semicrystalline phase with Ca/Si=1, the authors have prepared a series of xonotlite samples hydrothermally, at temperatures between 200 and 250 degrees C. Analysis in each case was by X-ray photoelectron spectroscopy, environmental scanning electron microscopy and X-ray diffraction. The authors’ use of a much lower water/solid ratio has indirectly confirmed the ‘through solution’ mechanism of xonotlite formation, where silicate dissolution is a key precursor of xonotlite formation. Concerning the role of temperature, too low a temperature (~200 degrees C) fails to yield xonotlite or leads to increased number of structural defects in the silicate chains of xonotlite and too high a temperature (>250 degrees C) leads to degradation of the xonotlite structure, through leaching of interchain calcium. Synthesis duration meanwhile leads to increased silicate polymerisation due to diminishing of the defects in the silicate chains and more perfect crystal morphologies

Моделирование магнитотаргетинга лекарственных средств, основанное на вычислении проницаемости электромагнитного поля в ткани организма человека

Analysis of studies in the field of targeted delivery of drugs, genes and stem cells showed a low level of accuracy of both applied and practical research in this area. Sufficiently encouraging results were obtained with extracorporeal electromagnetic action on a pharmacological complex with a ferromagnetic nanoparticle. With this approach, it is rather difficult to implement the algorithm for introducing the drug into the topographic region (target organ), since in practice, approaches to the clinical application of drug transport technology, taking into account the physicochemical properties of human body tissues, have not been studied in detail. The available models represent various physical and mathematical approaches that do not take into account the bioelectrical and electrostatic properties of the tissues of the organisms of experimental animals and humans. The creation of algorithms and software simulation of this technology will allow calculating variable frequency variables for magnetotargeting in a human digital phantom, which will reduce time spent at the stage of pilot and clinical trials and in the future will form the applied part of the innovative technology. The article presents the methodology and results of multiphysics and mathematical modeling in the Sim4Life for Science, V7.0 package on the example of calculating the control parameters of the electromagnetic field of the region in the area of normal administration of drugs – the vessels of the forearm.Анализ исследований в области таргетной доставки препаратов, генов и стволовых клеток показал низкий уровень точности прикладных и практических исследований в данной области. В настоящее время применяется экстракорпоральное электромагнитное воздействие на фармакологический комплекс с наночастицей ферромагнетика. Однако при таком подходе достаточно сложно реализовать алгоритм введения препарата в топографическую область (орган-мишень), поскольку на практике клиническое применение технологии транспорта лекарственных средств с учетом физико-химических свойств тканей организма человека детально не изучено. Существующие модели представляют различные физико-математические подходы, которые не учитывают биоэлектрические и электростатические свойства тканей изучаемых организмов животных и человека. Разработка алгоритмов и программного моделирования данной технологии позволит рассчитать переменные частоты для магнитотаргетинга в цифровом фантоме человека. Это уменьшит временные затраты на стадии пилотных и клинических испытаний. В статье приведены методология и результаты мультифизического и математического моделирования в пакете Sim4Life for Science, V7.0 на примере вычислений управляющих параметров электромагнитного поля региона в области обычного введения препаратов – в сосуды предплечья

Модель воздействия сфокусированного ультразвука на биологические ткани

To study tissue permeability under extracorporeal exposure to various types of radiation, it is necessary to use multiphysical and mathematical modeling of all stages of the technology being developed, taking into account the dielectric and acoustic properties of human body tissues. The technologies used in medicine with focused ultrasound often have a high level of artifacts in the visualization of diagnostic studies and complications during therapy. When modeling exposure to focused ultrasound, the applied solvers must take into account pressure wave propagation, density changes and jumps, non-linearity and diffusion losses that occur in human tissues, and offer simulation of acoustic propagation in inhomogeneous installations in near real time. The article presents the results of multiphysics and mathematical modeling in the Sim4Life for Science V7.0 package using a full-wave acoustic solver (P-ACOUSTICS) of modern computational acoustics.Для изучения проницаемости тканей при экстракорпоральном воздействии различными видами излучений необходимо использование мультифизического и математического моделирования всех этапов разрабатываемой технологии с учетом диэлектрических и акустических свойств тканей организма человека. Применяемые в медицине технологии воздействия сфокусированным ультразвуком достаточно часто имеют высокий уровень артефактов при визуализации диагностических исследований и осложнений при проведении терапии. При моделировании воздействия сфокусированным ультразвуком применяемые решатели должны учитывать распространение волны давления, изменения и скачки плотности, нелинейность и потери диффузии, которые происходят в тканях человека, и предлагать моделирование акустического распространения в неоднородных установках практически в реальном времени. В статье представлены результаты мультифизического и математического моделирования в пакете Sim4Life for Science V7.0 с применением полноволнового акустического решателя (P-ACOUSTICS) современной вычислительной акустики

Control of Azomethine Cycloaddition Stereochemistry by CF<inf>3</inf> Group: Structural Diversity of Fluorinated β-Proline Dimers

© 2016 American Chemical Society.β-Proline-functionalized dimers consisting of homochiral monomeric units were synthesized by a non-peptidic coupling method for the first time. The applied synthetic methodology is based on 1,3-dipolar cycloaddition chemistry of azomethine ylides and provides absolute control over the β-proline backbone stereogenic centers. An o-(trifluoromethyl)phenyl substituent contributes to appropriate stabilization of the definite acrylamide chiral cis conformation and to achieve the dipole reactivity that is not observed for aryl groups lacking strong electronegative character

Status on the Michigan‐MIT ultra‐cold polarized hydrogen jet target

Progress on the Mark‐II ultra‐cold polarized atomic hydrogen gas Jet target for the experiments NEPTUN‐A and NEPTUN at UNK is presented. We describe the performance and the present status of different components of the jet.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87525/2/698_1.pd

In Referense to the Disruption of Verbal Material Consolidation during Medical Sleep

We discuss the problem of the influence of the intravenous anesthetic “Propofol” on the process of human memory consolidation during surgery. This study is relevant because of two co-existing factors. The first is the wide use of propofol during surgical interventions in order to obtain a sedative effect. The second is presence of controversy data about the amnestic effects of the drug on the consolidation of human memory. So, we need to investigate this topic to ensure the safety of propofol medical usage. We used verbal stimuli — 40 words from the Russian language with non-repeating first three letters. Two types of reproduction indicators were compared between three groups — experimental, control and reference. There was no difference found between subjects who were put to sleep and those who were not put to sleep with an anesthetic during surgery. At the same time, the results of reproduction of the memorized material significantly differ from random ones in both groups.В работе обсуждается проблема влияния внутривенного анестетика «Пропофол» на процесс консолидации памяти человека во время хирургической операции. Актуальность исследования обусловлена широтой применения пропофола во время операционных вмешательств с целью получения седативного эффекта при наличии противоречивых данных о наличии амнезогенного влияния препарата на консолидацию памяти человека. Использовались вербальные стимулы — 40 слов из русского языка с неповторяющимися тремя первыми буквами. Два типа показателей воспроизведения сравнивались между тремя группами — экспериментальной, контрольной и референсной. Показано отсутствие различий между испытуемыми, введенными и не введенными в состояние сна с помощью анестетика во время хирургического вмешательства. При этом результаты воспроизведения запомненного материала значимо отличаются от случайных в обеих группах.Исследование выполнено при поддержке гранта РФФИ № 19-29-07069