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

ПАРЕНТЕРАЛЬНОЕ ПИТАНИЕ У ПАЦИЕНТОВ В КРИТИЧЕСКИХ СОСТОЯНИЯХ: ИСТОРИЯ СТАНОВЛЕНИЯ И РАЗВИТИЯ ПРОБЛЕМЫ

Parenteral nutrition in patients in critical conditions: the history of formation and development problem.Парентеральное питание у пациентов в критических состояниях: история становления и развития проблемы

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

Bovine Tuberculosis in a Nebraska Herd of Farmed Elk and Fallow Deer: A Failure of the Tuberculin Skin Test and Opportunities for Serodiagnosis

In 2009, Mycobacterium bovis infection was detected in a herd of 60 elk (Cervus elaphus) and 50 fallow deer (Dama dama) in Nebraska, USA. Upon depopulation of the herd, the prevalence of bovine tuberculosis (TB) was estimated at ∼71–75%, based upon histopathology and culture results. Particularly with elk, gross lesions were often severe and extensive. One year ago, the majority of the elk had been tested for TB by single cervical test (SCT), and all were negative. After initial detection of a tuberculous elk in this herd, 42 of the 59 elk were tested by SCT. Of the 42 SCT-tested elk, 28 were TB-infected with only 3/28 reacting upon SCT. After SCT, serum samples were collected from the infected elk and fallow deer from this herd at necropsy and tested by three antibody detection methods including multiantigen print immunoassay, cervidTB STAT-PAK, and dual path platform VetTB (DPP). Serologic test sensitivity ranged from 79 to 97% depending on the test format and host species. Together, these findings demonstrate the opportunities for use of serodiagnosis in the rapid detection of TB in elk and fallow deer

Progress in Development of Kharkov X-Ray Generator Nestor

The sources of the X-rays based on Compton scattering of intense Nd:YAG laser beam on electron beam circulating in a storage ring with beam energy 43-225 MeV is under construction in NSC KIPT. In the paper the progress in development and construction of Kharkov X-ray generator NESTOR is presented. The current status of the main facility system design and development are described. New scheme and main parameters of injection system are presented. The status of power supply system and control system is described. The facility is going to be in operation in the middle of 2007 and generated X-rays flux is expected to be of about 10{sup 13} phot/s

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

Potential for improved detection of bovine tuberculosis by targeting combined blood biomarkers in multi-test algorithms

Bovine tuberculosis (bTB) control programs can be improved by combined use of tests for humoral and cell-mediated immune responses targeting multiple biomarkers of Mycobacterium bovis. To further the diagnostic benefits of this approach, we used Dual Path Platform (DPP) technology to test sera from cattle with naturally acquired bTB in the United States (US) and Spain for the presence of M. bovis antigen, IgM and/or IgG antibodies to MPB70/MPB83 fusion antigen in conjunction with tuberculin skin tests (TST) or interferon-gamma release assays (IGRA). When TST was complemented with detection of IgM and IgG antibodies, the diagnostic sensitivity increased from 85.4% to 95.1% in the US and from 64.2% to 81.5% in Spain. Likewise, adding the DPP assays enhanced IGRA diagnostic sensitivity from 82.7% to 93.8% in Spain. Detection of circulating M. bovis antigen showed added value when used in combination with the DPP antibody assays but it was limited when analyzed in the context of TST or IGRA results. Present findings support the benefits of a multi-test approach for the ante-mortem diagnosis of bTB in cattle.This work was supported by the Small Business Innovation Research Program of the USDA National Institute of Food and Agriculture (Award No. 2016-33610-25688).Peer reviewe

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

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

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