АНАЛИЗИРУЮЩИЙ МАГНИТ ДЛЯ ТЕХНОЛОГИЧЕСКОГО УСКОРИТЕЛЯ ЭЛЕКТРОНОВ ЛУ-10М

Основной проблемой при использовании магнитов из редкоземельных материалов в ускорительных технологиях является изменение магнитных свойств материала под действием излучения. Особенно актуальна эта задача для мощных технологических ускорителей электронов с энергией до 10 МэВ. Для выбора наиболее стойкого материала были проведены исследования радиационной стойкости образцов магнитов из Sm2Co17 и Nd-Fe-B сплава. Постоянные магниты типа Sm2Co17 и Nd-Fe-B были изгтовлены методом порошковой технологи с использованием PLP процесса в производстве последних. Магнитные образцы подвергались прямому воздействию электронного пучка с энергией 10 МэВ и воздействию тормозного излучения этого пучка. Поглощённая доза от электронов для образцов составляла 16 Град (общий поток электронов, попавший на 1 см2 образца, был равен 1,4х1017) и 160 Град. Активность образцов после облучения изменилась в пределах допустимых норм. Этот факт существенно упрощает использование редкоземельных магнитных материалов в готовых изделиях ускорителей. В процессе облучения магниты охлаждались водой с температурой 38 °С для избежания перегрева. Для оценки изменения величины поля, создаваемого вокруг образца, использовался интеграл интерполированной нормальной к поверхности образца составляющей магнитного поля S по области интерполяции данных в относительных единицах. Для образцов из Nd-Fe-B сплава магнитный поток вокруг образца уменьшился и составил 0,92 и 0,717 от начального значения для указанных доз облучения. Магнитное поле вокруг образцов из Sm2Co17 сплава не изменилось в пределах точности измерений для тех же доз. На основе образцов из Sm2Co17 сплава размерами 30х24х12 мм было проведено моделирование и конструирование магнита для анализа пучка электронов технологического ускорителя на энергию до 10 МэВ. Наибольшее значение поля в медианной плоскости магнита равно 0,3110 Тл. Расстояние между полюсами магнита равно 25,25 мм. Эффективная длина магнита – 33,53 мм. Измеренные параметры поля магнита удовлетворяют заданным при разработке величинам. Магнит также может быть использован для настройки ускорителя в диапазоне энергий до 10 МэВ

Cryptosporidium Priming Is More Effective than Vaccine for Protection against Cryptosporidiosis in a Murine Protein Malnutrition Model

Cryptosporidium is a major cause of severe diarrhea, especially in malnourished children. Using a murine model of C. parvum oocyst challenge that recapitulates clinical features of severe cryptosporidiosis during malnutrition, we interrogated the effect of protein malnutrition (PM) on primary and secondary responses to C. parvum challenge, and tested the differential ability of mucosal priming strategies to overcome the PM-induced susceptibility. We determined that while PM fundamentally alters systemic and mucosal primary immune responses to Cryptosporidium, priming with C. parvum (106 oocysts) provides robust protective immunity against re-challenge despite ongoing PM. C. parvum priming restores mucosal Th1-type effectors (CD3+CD8+CD103+ T-cells) and cytokines (IFNγ, and IL12p40) that otherwise decrease with ongoing PM. Vaccination strategies with Cryptosporidium antigens expressed in the S. Typhi vector 908htr, however, do not enhance Th1-type responses to C. parvum challenge during PM, even though vaccination strongly boosts immunity in challenged fully nourished hosts. Remote non-specific exposures to the attenuated S. Typhi vector alone or the TLR9 agonist CpG ODN-1668 can partially attenuate C. parvum severity during PM, but neither as effectively as viable C. parvum priming. We conclude that although PM interferes with basal and vaccine-boosted immune responses to C. parvum, sustained reductions in disease severity are possible through mucosal activators of host defenses, and specifically C. parvum priming can elicit impressively robust Th1-type protective immunity despite ongoing protein malnutrition. These findings add insight into potential correlates of Cryptosporidium immunity and future vaccine strategies in malnourished children

Mixed infections with Opisthorchis viverrini and intestinal flukes in residents of Vientiane Municipality and Saravane Province in Laos

Faecal examinations for helminth eggs were performed on 1869 people from two riverside localities, Vientiane Municipality and Saravane Province, along the Mekong River, Laos. To obtain adult flukes, 42 people positive for small trematode eggs (Opisthorchis viverrini, heterophyid, or lecithodendriid eggs) were treated with a 20-30 mg kg(-1) single dose of praziquantel and purged. Diarrhoeic stools were then collected from 36 people (18 in each area) and searched for helminth parasites using stereomicroscopes. Faecal examinations revealed positive rates for small trematode eggs of 53.3% and 70.8% (average 65.2%) in Vientiane and Saravane Province, respectively. Infections with O. viverrini and six species of intestinal flukes were found, namely, Haplorchis taichui, H. pumilio, H. yokogawai, Centrocestus caninus, Prosthodendrium molenkampi, and Phaneropsolus bonnei. The total number of flukes collected and the proportion of fluke species recovered were markedly different in the two localities; in Vientiane, 1041 O. viverrini (57.8 per person) and 615 others (34.2 per person), whereas in Saravane, 395 O. viverrini (21.9 per person) and 155207 others (8622.6 per person). Five people from Saravane harboured no O. viverrini but numerous heterophyid and/or lecithodendriid flukes. The results indicate that O. viverrini and several species of heterophyid and lecithodendriid flukes are endemic in these two riverside localities, and suggest that the intensity of infection and the relative proportion of fluke species vary by locality along the Mekong River basin

Study design and rationale of "Synergistic Effect of Combination Therapy with Cilostazol and ProbUcol on Plaque Stabilization and Lesion REgression (SECURE)" study: a double-blind randomised controlled multicenter clinical trial

<p>Abstract</p> <p>Background</p> <p>Probucol, a cholesterol-lowering agent that paradoxically also lowers high-density lipoprotein cholesterol has been shown to prevent progression of atherosclerosis. The antiplatelet agent cilostazol, which has diverse antiatherogenic properties, has also been shown to reduce restenosis in previous clinical trials. Recent experimental studies have suggested potential synergy between probucol and cilostazol in preventing atherosclerosis, possibly by suppressing inflammatory reactions and promoting cholesterol efflux.</p> <p>Methods/design</p> <p>The Synergistic Effect of combination therapy with Cilostazol and probUcol on plaque stabilization and lesion REgression (SECURE) study is designed as a double-blind, randomised, controlled, multicenter clinical trial to investigate the effect of cilostazol and probucol combination therapy on plaque volume and composition in comparison with cilostazol monotherapy using intravascular ultrasound and Virtual Histology. The primary end point is the change in the plaque volume of index intermediate lesions between baseline and 9-month follow-up. Secondary endpoints include change in plaque composition, neointimal growth after implantation of stents at percutaneous coronary intervention target lesions, and serum levels of lipid components and biomarkers related to atherosclerosis and inflammation. A total of 118 patients will be included in the study.</p> <p>Discussion</p> <p>The SECURE study will deliver important information on the effects of combination therapy on lipid composition and biomarkers related to atherosclerosis, thereby providing insight into the mechanisms underlying the prevention of atherosclerosis progression by cilostazol and probucol.</p> <p>Trial registration number</p> <p>ClinicalTrials (NCT): <a href="http://www.clinicaltrials.gov/ct2/show/NCT01031667">NCT01031667</a></p

Tackling challenges in care of Alzheimer's disease and other dementias amid the COVID-19 pandemic, now and in the future

We have provided an overview on the profound impact of COVID-19 upon older people with Alzheimer's disease and other dementias and the challenges encountered in our management of dementia in different health-care settings, including hospital, outpatient, care homes, and the community during the COVID-19 pandemic. We have also proposed a conceptual framework and practical suggestions for health-care providers in tackling these challenges, which can also apply to the care of older people in general, with or without other neurological diseases, such as stroke or parkinsonism. We believe this review will provide strategic directions and set standards for health-care leaders in dementia, including governmental bodies around the world in coordinating emergency response plans for protecting and caring for older people with dementia amid the COIVD-19 outbreak, which is likely to continue at varying severity in different regions around the world in the medium term

A strategy to obtain axenic cultures of Arthrospira spp. cyanobacteria

A strategy to obtain axenic cultures of the cyanobacterium Arthrospira sp. (‘platensis’) Lefevre 1963/M-132-1 strain, consisting of a series of physical and chemical procedures, and the application of an optimized pool of antibiotics, is described in this paper. This strategy, which is an inexpensive and fast way to obtain axenic cultures, can be applied to Arthrospira spp. from culture collections or samples from their natural habitats to eliminate a wide spectrum of contaminants. A high alkaline treatment (pH 12, using KOH) of 72 h is a determinant initial procedure applied to eliminate protozoa and Microcystis sp. Bacteria were eliminated by an optimal antibiotic pool treatment, and Chroococcus sp. residuals were discarded by serial dilution. Optimal concentrations of the antibiotics composing the pool were obtained by a 24 factorial central composite rotatable design (CCRD) and Response Surface Methodology (RSM), resulting in: ampicillin 61.6 μg/ml, penicillin 85.8 μg/ml, cefoxitin 76.9 μg/ml, and meropenem 38.9 μg/ml. The results also indicate that cefoxitin was the most effective antibiotic of this pool. After obtaining the axenic culture, identification of Lefevre 1963/M-132-1 strain was performed using amplification and sequencing of the ITS region (including part of 16S rRNA, tRNA Ile, ITS, tRNA Ala and part of 23S rRNA region) and fatty acid composition data. Data base comparison revealed that Lefevre strain is closely related to A. platensis species (99% identity), while fatty acid composition data suggested A. maxima. These seemingly contradictory results are discussed

ДИЭЛЕКТРИЧЕСКИЕ ХАРАКТЕРИСТИКИ КОНДЕНСАТОРНЫХ СТРУКТУР НА ОСНОВЕ ПЛЕНОК ТИТАНАТА СТРОНЦИЯ, СФОРМИРОВАННЫХ ЗОЛЬ-ГЕЛЬ МЕТОДОМ

The thin film capacitors were formed on silicon. The capacitor is based on the strontium titanate multi-layer which was fabricated using the sol-gel method after heat treatment at the temperature 750 or 800 °C. The lower and upper electrodes were made from platinum and nickel accordingly. The average values of the dielectric permittivity, ε, and the loss factor, tg δ, were found between 150-190 and 0,06-0,1 respectively. The standard deviation values of the mentioned characteristics were calculated.Сформированы тонкопленочные конденсаторы на подложках кремния. Основу конденсатора составляет многослойная пленка титаната стронция, полученная золь-гель методом при температурах отжига 750-800 °С. Нижний электрод сформирован из платины, верхний - из никеля. Средние значения диэлектрической проницаемости и тангенса угла диэлекрических потерь лежат в пределах 150-190 и 0,06-0,1 соответственно. Приведены значения среднеквадратического отклонения указанных величи

Study of e+e−→ppˉe^+e^- \rightarrow p\bar{p} in the vicinity of ψ(3770)\psi(3770)

Using 2917 $\rm{pb}^{-1}$ of data accumulated at 3.773~$\rm{GeV}$, 44.5~$\rm{pb}^{-1}$ of data accumulated at 3.65~$\rm{GeV}$ and data accumulated during a $\psi(3770)$ line-shape scan with the BESIII detector, the reaction $e^+e^-\rightarrow p\bar{p}$ is studied considering a possible interference between resonant and continuum amplitudes. The cross section of $e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p}$, $\sigma(e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p})$, is found to have two solutions, determined to be ($0.059\pm0.032\pm0.012$) pb with the phase angle $\phi = (255.8\pm37.9\pm4.8)^\circ$ ($<$0.11 pb at the 90% confidence level), or $\sigma(e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p}) = (2.57\pm0.12\pm0.12$) pb with $\phi = (266.9\pm6.1\pm0.9)^\circ$ both of which agree with a destructive interference. Using the obtained cross section of $\psi(3770)\rightarrow p\bar{p}$, the cross section of $p\bar{p}\rightarrow \psi(3770)$, which is useful information for the future PANDA experiment, is estimated to be either ($9.8\pm5.7$) nb ($<17.2$ nb at 90% C.L.) or $(425.6\pm42.9)$ nb