Effect of Multiple Scattering on the Critical Electric Field for Runaway Electrons in the Atmosphere

A simple method for taking into account the multiple Coulomb scattering in construction of a separatrix (the line separating the regions of runaway and decelerating electrons in an electric field) is described. The desired line is obtained by solving a simple transcendental equation.Comment: 3 pages, 2 figure

Relativistic Laser-Matter Interaction and Relativistic Laboratory Astrophysics

The paper is devoted to the prospects of using the laser radiation interaction with plasmas in the laboratory relativistic astrophysics context. We discuss the dimensionless parameters characterizing the processes in the laser and astrophysical plasmas and emphasize a similarity between the laser and astrophysical plasmas in the ultrarelativistic energy limit. In particular, we address basic mechanisms of the charged particle acceleration, the collisionless shock wave and magnetic reconnection and vortex dynamics properties relevant to the problem of ultrarelativistic particle acceleration.Comment: 58 pages, 19 figure

Energetic particle influence on the Earth's atmosphere

This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

ПРОГНОСТИЧЕСКОЕ И ДИФФЕРЕНЦИАЛЬНО-ДИАГНОСТИЧЕСКОЕ ЗНАЧЕНИЕ ЭКСПРЕССИИ ЦИТОКЕРАТИНОВ 7 И 19 И ТИРЕОИДНОГО ФАКТОРА ТРАНСКРИПЦИИ-1 В НЕЙРОЭНДОКРИННЫХ ОПУХОЛЯХ ЛЕГКИХ РАЗНОЙ СТЕПЕНИ ЗЛОКАЧЕСТВЕННОСТИ

Background: Neuroendocrine tumors of the lung (NETL) are a wide range of tumors with various malignancy grades and prognosis. Despite their prevalence being 20 to 25% of all lung cancers, many aspects that impact their clinical course and prognosis are not well understood. Aim  – to identify morphological and immunophenotypic characteristics of various NETL types would that more accurately reflect their biological potential and allow for prediction of their unfavorable clinical outcomes. Materials and methods: We performed immunohistochemical assessment of the diagnostic biopsies and surgical specimens from 152 patients with NETL aged 53 ± 13 years and identified 49  typical carcinoids, 32 atypical carcinoids, 60  small cell neuroendocrine carcinomas and 11  large cell neuroendocrine carcinomas, which accounted for 32.2, 21.1, 39.5 and 7.2%, respectively. Markers of neuroendocrine differentiation, such as synaptophysin, chromogranin A  and CD56, as well as cytokeratins 7 and 19, thyroid transcription factor-1 (TTF-1), and Ki67 were used. The results were analyzed with analysis of variance (ANOVA), chi-square test (χ²), and post-hoc comparisons with the Bonferroni correction. Results: Most often, the expression of cytokeratins 7 and 19 was found in large cell neuroendocrine carcinoma (72.7 and 90.9%, respectively), less frequently, in atypical carcinoids and small cell neuroendocrine carcinomas (50 and 53.3%; 41.7 and 64.6% of cases, respectively), whereas in typical carcinoids it was rare (5.9 and 15.9%, respectively). The rates of cytokeratin 7 and 19 expression were significantly lower in the typical carcinoids, compared to the atypical carcinoids, small cell neuroendocrine carcinomas and large cell neuroendocrine carcinomas (р 0.05, χ²). The expression of cytokeratin 19 was significantly more common for large cell neuroendocrine carcinomas, than for small cell neuroendocrine carcinomas and atypical carcinoids (р 0.01, χ²). The expression of TTF-1 was very rare in the typical carcinoid cells (6.5% of cases) and significantly more often in atypical carcinoids (61.5%) and in small cell neuroendocrine carcinomas and large cell neuroendocrine carcinomas (82.7 and 77.8% of cases, respectively). TTF-1 expression was significantly less frequent in typical than in atypical carcinoids, small cell neuroendocrine carcinomas and large cell neuroendocrine carcinomas (р 0.01, χ²). The mean index of tumor cell proliferation (Ki67) was the lowest in typical carcinoids (2.6%), amounted to 12% in atypical carcinoids, to 44% in large cell neuroendocrine carcinomas and reached the maximum of 61% in small cell neuroendocrine carcinomas. There were significant differences in the mean Ki67 index in the NETL 4 groups (р 0.001, ANOVA). Conclusion: Expression of TTF-1, cytokeratin 7 and 19 in the neuroendocrine tumors of the lung is characteristic for a  less differentiated cell immunophenotype and allows for identification of the risk group with unfavorable clinical outcome among low-grade typical and atypical carcinoids.Актуальность. Нейроэндокринные опухоли легких (НЭОЛ) представляют собой целый спектр опухолей, различающихся по степени злокачественности и  прогнозу. Несмотря на их распространенность  – от  20 до 25% всех случаев рака данной локализации – многие аспекты, определяющие особенности клинического течения НЭОЛ и прогноз, еще недостаточно хорошо изучены. Цель  – выявить морфологические и  иммунофенотипические особенности разных типов НЭОЛ, которые бы более точно отражали их биологический потенциал и  позволяли прогнозировать менее благоприятное клиническое течение. Материал и  методы. Проводили иммуногистохимическое исследование диагностических биопсий и операционного материала от 152 пациентов с НЭОЛ в возрасте 53±13 лет. Были диагностированы 49 типичных карциноидов, 32 атипичных карциноида, 60 мелкоклеточных нейроэндокринных карцином/раков и  11 крупноклеточных нейроэндокринных карцином/раков, которые составили 32,2, 21,1, 39,5 и  7,2% соответственно. Использовали маркеры нейроэндокринной дифференцировки  – синаптофизин, хромогранин А  и  CD56, а  также цитокератины  7 и  19, тиреоидный фактор транскрипции-1 (TTF-1), Ki67. Pезультаты подвергли статистической обработке с  использованием дисперсионного анализа (ANOVA), критерия χ², апостериорных сравнений с  поправкой Бонферрони. Результаты. Чаще всего экспрессия цито- кератинов 7 и 19 встречалась в группе крупноклеточной нейроэндокринной карциномы – в 72,7 и 90,9% случаев соответственно, реже в  группе атипичного карциноида (50 и  53,3%) и  мелкоклеточной нейроэндокринной карциномы (41,7 и 64,6%), редко – типичного карциноида (5,9 и 15,9%). Частота экспрессии цитокератинов 7 и  19 была статистически значимо меньше в  группе типичного карциноида по сравнению с  атипичным карциноидом, мелкоклеточной и  крупноклеточной нейроэндокринными карциномами (р0,05, χ², 0,05, χ², апостериорные сравнения). Экспрессия цитокератина  19 значимо чаще наблюдалась в крупноклеточных нейроэндокринных карциномах, чем в мелкоклеточных нейроэндокринных карциномах и атипичных карциноидах (р 0,05 χ², апостериорные сравнения). Экспрессия TTF-1 в  клетках типичных карциноидов выявлялась очень редко – в 6,5% случаев, в атипичных карциноидах значительно чаще  – в  61,5%, а  в мелкоклеточных и  крупноклеточных нейроэндокринных карциномах  – в  подавляющем большинстве случаев: 82,7 и  77,8% соответственно. Частота экспрессии TTF-1 в  типичных карциноидах была значимо меньше, чем в  атипичных карциноидах, мелкоклеточных и  крупноклеточных нейроэндокринных карциномах (р 0,01, χ², апостериорные сравнения). Средний индекс пролиферации опухолевых клеток Ki67 был самым низким в  группе типичного карциноида  – 2,6%, в  группе атипичного карциноида он достигал 12%, крупноклеточной нейроэндокринной карциномы  – 44%, а  максимальным оказался при мелкоклеточной нейроэндокринной карциноме – 61%. Имелись статистически значимые различия в величине среднего индекса Ki67 во всех 4 группах НЭОЛ (р 0,001, ANOVA, апостериорные сравнения). Заключение. Экспрессия в нейроэндокринных опухолях легкого TTF-1, цитокератинов 7 и 19 характеризует менее дифференцированный клеточный иммунофенотип и  позволяет выделить среди высокодифференцированных типичных и атипичных карциноидов группу риска с менее благоприятным клиническим течением.