Investigation of two-photon 2s -> 1s decay in one-electron and one-muon ions

We have studied the radiative decay of the 2s state of one-electron and one-muon ions, where the two-photon mechanism plays an important role. Due to the nuclear size corrections the radiative decay of the 2s state in the electron and muon ions is qualitatively different. Based on the accurate relativistic calculation, we introduced a two-parameter approximation, which makes it possible to describe the two-photon angular-differential transition probability for the polarized emitted photons with high accuracy. The emission of photons with linear and circular polarizations was studied separately. We also investigated the transition probabilities for the polarized initial and final states. The investigation was performed for ions with atomic numbers 1 < Z < 120.Comment: 18 pages, 8 figure

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

Potential for rapid antibody detection to identify tuberculous cattle with non-reactive tuberculin skin test results

Abstract Background Bovine tuberculosis (TB) control programs generally rely on the tuberculin skin test (TST) for ante-mortem detection of Mycobacterium bovis-infected cattle. Results Present findings demonstrate that a rapid antibody test based on Dual-Path Platform (DPP®) technology, when applied 1-3 weeks after TST, detected 9 of 11 and 34 of 52 TST non-reactive yet M. bovis-infected cattle from the US and GB, respectively. The specificity of the assay ranged from 98.9% (n = 92, US) to 96.0% (n = 50, GB) with samples from TB-free herds. Multi-antigen print immunoassay (MAPIA) revealed the presence of antibodies to multiple antigens of M. bovis in sera from TST non-reactors diagnosed with TB. Conclusions Thus, use of serologic assays in series with TST can identify a significant number of TST non-reactive tuberculous cattle for more efficient removal from TB-affected herds

Diagnosis of Tuberculosis in the Wild Boar (Sus scrofa): A Comparison of Methods Applicable to Hunter-Harvested Animals

To obtain robust epidemiological information regarding tuberculosis (TB) in wildlife species, appropriate diagnostic methods need to be used. Wild boar (Sus scrofa) recently emerged as a major maintenance host for TB in some European countries. Nevertheless, no data is available to evaluate TB post-mortem diagnostic methods in hunter-harvested wild boar. METHODOLOGY/PRINCIPAL FINDINGS: Six different diagnostic methods for TB were evaluated in parallel in 167 hunter-harvested wild boar. Compared to bacteriological culture, estimates of sensitivity of histopathology was 77.8%, gross pathology 72.2%, PCR for the MPB70 gene 66.7%, detection of acid-fast bacilli (AFB) in tissue contact smears 55.6% and in histopathology slides 16.7% (estimated specificity was 96.7%, 100%, 100%, 94.4% and 100%, respectively). Combining gross pathology with stained smears in parallel increased estimated sensitivity to 94.4% (94.4% specificity). Four probable bacteriological culture false-negative animals were identified by Discriminant Function Analysis. Recalculating the parameters considering these animals as infected generated estimated values for sensitivity of bacteriology and histopathology of 81.8%, gross pathology 72.7%, PCR for the MPB70 gene 63.6%, detection of AFB in tissue contact smears 54.5% and in histopathology slides 13.6% (estimated specificity was 100% for gross pathology, PCR, bacteriology and detection of AFB in histopathology slides, 96.7% for histopathology and 94.4% for stained smears). CONCLUSIONS/SIGNIFICANCE: These results show that surveys for TB in wild boar based exclusively on gross pathology considerably underestimate prevalence, while combination of tests in parallel much improves sensitivity and negative predictive values. This finding should thus be considered when planning future surveys and game meat inspection schemes. Although bacteriological culture is the reference test for TB diagnosis, it can generate false-negative results and this should be considered when interpreting data.This study was funded by laboratory funds from Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript

Oral vaccination with heat inactivated Mycobacterium bovis activates the complement system to protect against tuberculosis

Tuberculosis (TB) remains a pandemic affecting billions of people worldwide, thus stressing the need for new vaccines. Defining the correlates of vaccine protection is essential to achieve this goal. In this study, we used the wild boar model for mycobacterial infection and TB to characterize the protective mechanisms elicited by a new heat inactivated Mycobacterium bovis vaccine (IV). Oral vaccination with the IV resulted in significantly lower culture and lesion scores, particularly in the thorax, suggesting that the IV might provide a novel vaccine for TB control with special impact on the prevention of pulmonary disease, which is one of the limitations of current vaccines. Oral vaccination with the IV induced an adaptive antibody response and activation of the innate immune response including the complement component C3 and inflammasome. Mycobacterial DNA/RNA was not involved in inflammasome activation but increased C3 production by a still unknown mechanism. The results also suggested a protective mechanism mediated by the activation of IFN-γ producing CD8+ T cells by MHC I antigen presenting dendritic cells (DCs) in response to vaccination with the IV, without a clear role for Th1 CD4+ T cells. These results support a role for DCs in triggering the immune response to the IV through a mechanism similar to the phagocyte response to PAMPs with a central role for C3 in protection against mycobacterial infection. Higher C3 levels may allow increased opsonophagocytosis and effective bacterial clearance, while interfering with CR3-mediated opsonic and nonopsonic phagocytosis of mycobacteria, a process that could be enhanced by specific antibodies against mycobacterial proteins induced by vaccination with the IV. These results suggest that the IV acts through novel mechanisms to protect against TB in wild boar

The start of X-ray generator NESTOR comissioning

The first results of the NESTOR facility commissioning are presented. 60 MeV electron linac injector has been tested and the first electron beam with project parameters was registered at the screen monitors. Electron beam was passed through the transportation channel and injection system. The beamh of electrons was observed and controlled in the screen monitors in the expected range.Перші результати вводу в експлуатацію генератора НЕСТОР представлені. Інжектор-лінійний прискорювач на 60 МеВ електронів був випробуван, та перший пучок із проектними параметрами було зареєстровано на екранах моніторів. Електронний пучок проведено крізь канал транспортування та системи вводу в вакуумну камеру накопичувача. Пучок електронів спостерігається і контролюється на екранах моніторів в очікуваному діапазоні.Представлены первые результаты ввода в эксплуатацию генератора НЕСТОР. Инжектор-линейный ускоритель на 60 МэВ электронов был испытан, и первый пучок с проектными параметрами был зарегистрирован на экранах мониторов. Электронный пучок проведен через канал транспортировки и системы ввода в вакуумную камеру накопителя. Пучок электронов наблюдается и контролируется на экране мониторов в ожидаемом диапазоне

Seroprevalence and Risk Factors Associated to Mycobacterium bovis in Wild Artiodactyl Species from Southern Spain, 2006–2010

The control of bovine tuberculosis (bTB) is at a critical point in the last stage of eradication in livestock. Wildlife species recently have emerged infected with TB in Europe, particularly ungulates in the Iberian Peninsula. Epidemiological information regarding TB in wild ungulates including affected species, prevalence, associated risk factors and appropriate diagnostic methods need to be obtained in these countries

Protection against Tuberculosis in Eurasian Wild Boar Vaccinated with Heat-Inactivated Mycobacterium bovis

Tuberculosis (TB) caused by Mycobacterium bovis and closely related members of the Mycobacterium tuberculosis complex continues to affect humans and animals worldwide and its control requires vaccination of wildlife reservoir species such as Eurasian wild boar (Sus scrofa). Vaccination efforts for TB control in wildlife have been based primarily on oral live BCG formulations. However, this is the first report of the use of oral inactivated vaccines for controlling TB in wildlife. In this study, four groups of 5 wild boar each were vaccinated with inactivated M. bovis by the oral and intramuscular routes, vaccinated with oral BCG or left unvaccinated as controls. All groups were later challenged with a field strain of M. bovis. The results of the IFN-gamma response, serum antibody levels, M. bovis culture, TB lesion scores, and the expression of C3 and MUT genes were compared between these four groups. The results suggested that vaccination with heat-inactivated M. bovis or BCG protect wild boar from TB. These results also encouraged testing combinations of BCG and inactivated M. bovis to vaccinate wild boar against TB. Vaccine formulations using heat-inactivated M. bovis for TB control in wildlife would have the advantage of being environmentally safe and more stable under field conditions when compared to live BCG vaccines. The antibody response and MUT expression levels can help differentiating between vaccinated and infected wild boar and as correlates of protective response in vaccinated animals. These results suggest that vaccine studies in free-living wild boar are now possible to reveal the full potential of protecting against TB using oral M. bovis inactivated and BCG vaccines

Pattern Recognition in Pulmonary Tuberculosis Defined by High Content Peptide Microarray Chip Analysis Representing 61 Proteins from M. tuberculosis

Background: Serum antibody-based target identification has been used to identify tumor-associated antigens (TAAs) for development of anti-cancer vaccines. A similar approach can be helpful to identify biologically relevant and clinically meaningful targets in M.tuberculosis (MTB) infection for diagnosis or TB vaccine development in clinically well defined populations. Method: We constructed a high-content peptide microarray with 61 M.tuberculosis proteins as linear 15 aa peptide stretches with 12 aa overlaps resulting in 7446 individual peptide epitopes. Antibody profiling was carried with serum from 34 individuals with active pulmonary TB and 35 healthy individuals in order to obtain an unbiased view of the MTB epitope pattern recognition pattern. Quality data extraction was performed, data sets were analyzed for significant differences and patterns predictive of TB+/2. Findings: Three distinct patterns of IgG reactivity were identified: 89/7446 peptides were differentially recognized (in 34/34 TB+ patients and in 35/35 healthy individuals) and are highly predictive of the division into TB+ and TB2, other targets were exclusively recognized in all patients with TB (e.g. sigmaF) but not in any of the healthy individuals, and a third peptide set was recognized exclusively in healthy individuals (35/35) but no in TB+ patients. The segregation between TB+ and TB2 does no