QED cascades induced by circularly polarized laser fields

The results of Monte-Carlo simulations of electron-positron-photon cascades initiated by slow electrons in circularly polarized fields of ultra-high strength are presented and discussed. Our results confirm previous qualitative estimations [A.M. Fedotov, et al., PRL 105, 080402 (2010)] of the formation of cascades. This sort of cascades has revealed the new property of the restoration of energy and dynamical quantum parameter due to the acceleration of electrons and positrons by the field and may become a dominating feature of laser-matter interactions at ultra-high intensities. Our approach incorporates radiation friction acting on individual electrons and positrons.Comment: 13 pages, 10 figure

Динамика распространенности бронхиальной астмы у детей в Новосибирске

Six-year dynamics of epidemiology of bronchial asthma was analyzed in Novosibirsk according to a common standardized protocol of the "International Study of Asthma and Allergic Diseases in Children" (ISAAC) programme. The pathology spread was studied using a total surveying among first-form and eight-form pupils (the survey involved 7291 pupils 1996, 6631 ones in 1999 and 6943 children in 2002). The results showed stable spread of bronchial asthma symptoms among the senior and junior pupils and prevalence of mild asthma with rare exacerbations in both the groups. A progredient growth of severe asthma attack rate was noted in eight-form pupils. An increase in frequency of combined upper and lower airway pathologies was registered with reduction in skin atopy rate. A problem of underestimating of the pathology was discussed.Исследована 6-летняя динамика эпидемиологии бронхиальной астмы по единым стандартизованным протоколам программы "Международное исследование астмы и аллергических заболеваний у детей" (ISAAC) в Новосибирске. Изучение распространенности патологии проводилось при сплошном анкетировании учеников 1-х и 8-х классов (7291 школьник в 1996 г., 6631 — в 1999 г. и 6943 — в 2002 г.). В динамике выявлены стабильная распространенность симптомов бронхиальной астмы у старших и младших школьников, сохранение преобладания легких редко рецидивировавших форм патологии в обеих возрастных группах. Отмечен прогредиентный рост тяжелых приступов удушья у восьмиклассников. В популяции школьников зарегистрировано увеличение сочетанного поражения верхних и нижних отделов респираторного тракта с сокращением частоты кожных форм атопии. Отражена проблема гиподиагностики патологии

Properties of electrons scattered on a strong plane electromagnetic wave with a linear polarization: classical treatment

The relations among the components of the exit momenta of ultrarelativistic electrons scattered on a strong electromagnetic wave of a low (optical) frequency and linear polarization are established using the exact solutions to the equations of motion with radiation reaction included (the Landau-Lifshitz equation). It is found that the momentum components of the electrons traversed the electromagnetic wave depend weakly on the initial values of the momenta. These electrons are mostly scattered at the small angles to the direction of propagation of the electromagnetic wave. The maximum Lorentz factor of the electrons crossed the electromagnetic wave is proportional to the work done by the electromagnetic field and is independent of the initial momenta. The momentum component parallel to the electric field strength vector of the electromagnetic wave is determined only by the diameter of the laser beam measured in the units of the classical electron radius. As for the reflected electrons, they for the most part lose the energy, but remain relativistic. There is a reflection law for these electrons that relates the incident and the reflection angles and is independent of any parameters.Comment: 12 pp, 3 fig

Particle Acceleration in Pulsar Wind Nebulae: PIC modelling

We discuss the role of particle-in-cell (PIC) simulations in unveiling the origin of the emitting particles in PWNe. After describing the basics of the PIC technique, we summarize its implications for the quiescent and the flaring emission of the Crab Nebula, as a prototype of PWNe. A consensus seems to be emerging that, in addition to the standard scenario of particle acceleration via the Fermi process at the termination shock of the pulsar wind, magnetic reconnection in the wind, at the termination shock and in the Nebula plays a major role in powering the multi-wavelength signatures of PWNe.Comment: 32 pages, 16 figures, to appear in the book "Modelling Nebulae" edited by D. Torres for Springer, based on the invited contributions to the workshop held in Sant Cugat (Barcelona), June 14-17, 201

Применение различных схем противовирусной терапии ОРВИ у детей

To optimize selection of antiviral agents for children in routine practice of ARVI management, a double-center, prospective, open-label, randomized study of efficacy and tolerability of schemes including Ergoferon, Cagocel, Arbidol in children > 3 years was performed throughout two epidemic seasons (fall 2012 — spring 2014). In total 152 children with ARVI symptoms lasting for no more than 48 hours were randomized into 3 groups, i.e. Ergoferon (group E, n = 67), Cagocel (group C, n = 40), Arbidol (group A, n = 45). At visits 2 and 3 proportion of children with normalized body temperature (primary criterion) and intensity of intoxication and catarrhal syndrome were evaluated. At visit 3 the following parameters were measured: efficacy index (efficacy and tolerability assessment by the doctor using CGI scale) and evaluation of safety and tolerability of the study drug by parents/representatives of the child; incidence of medical product prescriptions was recorded, i.e. the total number of prescriptions per group, incidence and duration of administration of individual groups of agents. To analyze and evaluate the data obtained, conventional methods of parametric and non-parametric statistics were applied. Groups C and A were not statistically different in baseline characteristics and throughout efficacy criteria assessment. A new group 2 (n=85) was generated out of these groups for further analysis. At visit 2 group 1 and group 2 showed normalization in morning and evening body temperature in 76% and 79% in group 1, respectively, vs. 73% and 79% — in group 2 (2, p > 0.05). 100% subjects in group 1 and 98% — in group 2 did not have intoxication signs, or the rank value of mild intoxication did not exceed 1 (mild). Proportion of subjects with mild catarrhal syndrome at rank 2—3 in group 1 vs. baseline reduced from 15% to 3%, in group 2 — from 18% to 8%. At visit 3, 94% subjects in group 1 and 95% — in group did not show clinical intoxication signs. Almost every one in three children in both groups had catarrhal signs completely resolved by the end of the treatment, in 70% and 65% cases in groups 1 and 2 severity of catarrhal syndrome did not exceed rank 1 (2, p > 0.05). No adverse effects associated with the study scheme components have been reported during the study. Efficacy and tolerability evaluation by the doctors using CGI in group 1 was 3.37 ± 0.65 (M ± SD, 95% CI 3.22-3.53) vs. 3.23 ± 0.77 (M ± SD, 95%CI 3.08—3.39) in group 2 (Т-test, p = 0.38). In group 1 maximum rating (4 scores) was assigned by the doctors in 46%, minimum one (2 scores) — in 9%, while in group 2 the equivalent proportions were 40% and 16%, respectively (p = 0.44 for maximum score and p = 0.17 for minimum score). Therapeutic efficacy evaluation by  parents in group 1 was 3.73 ± 0.57 (M ± SD, 95% CI 3.59-3.87) vs. 3.35 ± 0.72 (M ± SD, 95%CI 3.20—3.50) in group 2; Т-test, p = 0.04. According to frequency assessment, positive scoring (4-5 scores) was more prevalent among parents in group 1: 71% vs. 44% (group 2), 2 test, p = 0.001, minimum scoring (2 scores) was less common in group 1: 1.5% vs. 12% (group 2),?2 test, p = 0.02. Evaluation of therapeutic tolerability by parents in group 1 (4.04 ± 0.53, 95%CI 3.91—4.18) was higher as compared to group 2 (3.82 ± 0.53, 95%CI 3.71—3.93); Т-test, p = 0.01. Maximum scoring (5 scores) was obtained in group 1 in 16% cases, in group 2 — 6% (2 test, p = 0.03). Analysis of additional drug prescriptions revealed that 3.6 ± 1.2 prescriptions have been made on average in group 1 vs. 5.0 ± 1.2 in group 2 (Т-test, р = 0.01). Proportion of children receiving more than 5 drugs was 18% in group 1 vs. 32% in group 2 (2 test, p = 0.05). Seven drugs were given to 3% children in group 1 and 12% — in group 2 (exact Fisher’s test, p = 0.067). Duration of therapy with H1-histamine blockers in group 1 was 5 days (Me: 5.0 (5.0; 6.0) vs. 8.5 days (Me: 8.5 (7.5; 10.0) in group 2 (U-test, р = 0.006). Therefore, comparable clinical efficacy and tolerability of anti-ARVI therapeutic schemes were revealed in children using Ergoferon, Cagocel and Arbidol. At that Ergoferon group showed higher therapeutic quality scoring (efficacy and tolerability), both according to the doctors (CGI scale) and parents. Reduced number of prescriptions and duration of drug therapy in Ergoferon group for ARVI management were revealed.С целью оптимизации выбора противовирусных средств у детей в рутинной практике лечения ОРВИ было проведено двухцентровое проспективное открытое рандомизированное исследование эффективности и переносимости схем терапии с применением Эргоферона, Кагоцела, Арбидола у детей в возрасте старше 3 лет на протяжении двух эпидсезонов (осень 2012 — весна 2014 гг.). 152 ребенка с симптомами ОРВИ, продолжительностью не более 48 часов, были рандомизированы в 3 группы, в которых для лечения ОРВИ применялись Эргоферон (группа Э, 67 пациентов), Кагоцел (группа К, 40 пациентов), Арбидол (группа А, 45 пациентов). На 2-м и 3-м визитах оценивалась доля пациентов с нормализацией температуры тела (первичный критерий), выраженность интоксикационного и катарального синдромов. На 3-м визите регистрировались: индекс эффективности (оценка врачом эффективности и переносимости терапии по шкале CGI) и оценки эффективности и переносимости исследуемого препарата со слов родителей/представителей ребенка; анализировалась частота назначения медикаментов — общее число назначений в группе, частота и продолжительность применения отдельных групп препаратов. Для анализа и оценки полученных данных применялись стандартные методы параметрической и непараметрической статистики. Группы К и А не имели статистически значимых различий в исходных характеристиках и в динамике оцениваемых критериев эффективности и для дальнейшего анализа из них была сформирована новая группа 2 (85 пациентов). На 2-м визите отмечалась нормализация утренней и вечерней температуры тела в 76 и 79% соответственно, в 1-й группе, против 73 и 79% — во 2-й группе (2, p > 0,05). 100% пациентов из 1-й группы и 98% пациентов — из 2-й группы не имели признаков интоксикации или ранговый показатель синдрома интоксикации был не выше 1 (слабо выражен). Доля пациентов с выраженностью катарального синдрома на уровне 2-3 рангов в 1-й группе по сравнению с исходными данными сократилась с 15 до 3%, во 2-й группе — с 18 до 8%. На 3-м визите 94% пациентов в 1-й группе и 95% во — 2-й группе не имели клинических проявлений интоксикации, практически, каждый третий ребенок из обеих групп полностью избавился от катаральных явлений к окончанию лечения, в 70 и в 65% случаев в 1-й и 2-й группах выраженность катарального синдрома не превышала 1 ранга (2, p > 0,05). В ходе проведения исследования не было зарегистрировано побочных эффектов, связанных с приемом тех или иных компонентов исследуемых схем терапии. Оценка эффективности и переносимости, данная врачами по шкале CGI в 1-й группе составила 3,37 ± 0,65 (M ± SD, 95%CI 3,22—3,53), против 3,23 ± 0,77 (M ± SD, 95%CI 3,08-3,39) во 2-й группе (Т-критерий, p = 0,38). В 1-й группе максимальную оценку (4 балла) врачи поставили в 46%, а минимальную (2 балла) — в 9%, в то время, как во 2-й группе аналогичные доли составили 40 и 16% соответственно (p = 0,44 для максимальной оценки и p = 0,17 для минимальной оценки). Оценка эффективности терапии родителями в 1-й группе составила 3,73 ± 0,57 (M ± SD, 95%CI 3,59-3,87) против 3,35 ± ± 0,72 (M ± SD, 95%CI 3,20—3,50) в 2-й группе; Т-критерий, p = 0,04. По данным частотного анализа балльных оценок, положительные оценки (4—5 баллов) чаще ставили родители детей из 1-й группы: 71% против 44% (2-я группа), критерий 2, p = = 0,001, минимальные оценки (2 балла) реже встречались во 1-й группе: 1,5% против 12% (2-я группа), критерий 2, p = 0,02. Оценка переносимости терапии, данная родителями в 1-й группе (4,04 ± 0,53, 95%CI 3,91-4,18) была более высокой, чем в 2-й группе (3,82 ± 0,53, 95%CI 3,71—3,93); Т-критерий, p = 0,01. Максимальная оценка в 5 баллов получена в 1-й группе в 16% случаев, а в 2-й группе — 6% (критерий 2, p = 0,03). В ходе анализа дополнительных медикаментозных назначений было выявлено, что в среднем в 1-й группе осуществлялось 3,6 ± ± 1,2 назначений, против 5,0 ± 1,2 во 2-й группе (Т-критерий, р = 0,01). Доля детей, получавших более 5 медикаментов, в 1-й группе составила 18%, тогда как во 2-й группе доля таких назначений была выше — 32% (критерий 2, p = 0,05). 7 препаратов получало 3% детей в 1-й группе и 12% пациентов во 2-й группе (точный критерий Фишера, p = 0,067). Продолжительности терапии H1 гистамино-блокаторами 1-й группе составила 5 дней (Me: 5,0 (5,0; 6,0) против 8,5 дней (Me: 8,5 (7,5; 10,0) их использования во 2-й группе (U-критерий, р = 0,006). Таким образом, выявлена сопоставимая клиническая эффективность и переносимость применения схем терапии ОРВИ у детей с использованием Эргоферона, Кагоцела и Арбидола. При этом в группе детей, получавших Эргоферон, чаще регистрировались более высокие оценки качества терапии (эффективность и переносимость), как со стороны врачей (по шкале CGI), так и со стороны родителей. Выявлено уменьшение числа назначаемых препаратов и снижение продолжительности применения препаратов в группе детей, получавших Эргоферон для лечения ОРВИ

Conceptual design report for the LUXE experiment

This Conceptual Design Report describes LUXE (Laser Und XFEL Experiment), an experimental campaign that aims to combine the high-quality and high-energy electron beam of the European XFEL with a powerful laser to explore the uncharted terrain of quantum electrodynamics characterised by both high energy and high intensity. We will reach this hitherto inaccessible regime of quantum physics by analysing high-energy electron-photon and photon-photon interactions in the extreme environment provided by an intense laser focus. The physics background and its relevance are presented in the science case which in turn leads to, and justifies, the ensuing plan for all aspects of the experiment: Our choice of experimental parameters allows (i) field strengths to be probed where the coupling to charges becomes non-perturbative and (ii) a precision to be achieved that permits a detailed comparison of the measured data with calculations. In addition, the high photon flux predicted will enable a sensitive search for new physics beyond the Standard Model. The initial phase of the experiment will employ an existing 40 TW laser, whereas the second phase will utilise an upgraded laser power of 350 TW. All expectations regarding the performance of the experimental set-up as well as the expected physics results are based on detailed numerical simulations throughout

Letter of Intent for the LUXE Experiment

This Letter of Intent describes LUXE (Laser Und XFEL Experiment), an experiment that aims to use the high-quality and high-energy electron beam of the European XFEL and a powerful laser. The scientific objective of the experiment is to study quantum electrodynamics processes in the regime of strong fields. High-energy electrons, accelerated by the European XFEL linear accelerator, and high-energy photons, produced via Bremsstrahlung of those beam electrons, colliding with a laser beam shall experience an electric field up to three times larger than the Schwinger critical field (the field at which the vacuum itself is expected to become unstable and spark with spontaneous creation of electron-positron pairs) and access a new regime of quantum physics. The processes to be investigated, which include nonlinear Compton scattering and nonlinear Breit-Wheeler pair production, are relevant to a variety of phenomena in Nature, e.g. in the areas of astrophysics and collider physics and complement recent results in atomic physics. The setup requires in particular the extraction of a minute fraction of the electron bunches from the European XFEL accelerator, the installation of a powerful laser with sophisticated diagnostics, and an array of precision detectors optimised to measure electrons, positrons and photons. Physics sensitivity projections based on simulations are also provided

Molecular pathways leading to loss of skeletal muscle mass in cancer cachexia can findings from animal models be translated to humans?

Background: Cachexia is a multi-factorial, systemic syndrome that especially affects patients with cancer of the gastrointestinal tract, and leads to reduced treatment response, survival and quality of life. The most important clinical feature of cachexia is the excessive wasting of skeletal muscle mass. Currently, an effective treatment is still lacking and the search for therapeutic targets continues. Even though a substantial number of animal studies have contributed to a better understanding of the underlying mechanisms of the loss of skeletal muscle mass, subsequent clinical trials of potential new drugs have not yet yielded any effective treatment for cancer cachexia. Therefore, we questioned to which degree findings from animal studies can be translated to humans in clinical practice and research. Discussion: A substantial amount of animal studies on the molecular mechanisms of muscle wasting in cancer cachexia has been conducted in recent years. This extensive review of the literature showed that most of their observations could not be consistently reproduced in studies on human skeletal muscle samples. However, studies on human material are scarce and limited in patient numbers and homogeneity. Therefore, their results have to be interpreted critically. Summary: More research is needed on human tissue samples to clarify the signaling pathways that lead to skeletal muscle loss, and to confirm pre-selected drug targets from animal models in clinical trials. In addition, improved diagnostic tools and standardized clinical criteria for cancer cachexia are needed to conduct standardized, randomized controlled trials of potential drug candidates in the future

Testis-specific glyceraldehyde-3-phosphate dehydrogenase: origin and evolution

<p>Abstract</p> <p>Background</p> <p>Glyceraldehyde-3-phosphate dehydrogenase (GAPD) catalyses one of the glycolytic reactions and is also involved in a number of non-glycolytic processes, such as endocytosis, DNA excision repair, and induction of apoptosis. Mammals are known to possess two homologous GAPD isoenzymes: GAPD-1, a well-studied protein found in all somatic cells, and GAPD-2, which is expressed solely in testis. GAPD-2 supplies energy required for the movement of spermatozoa and is tightly bound to the sperm tail cytoskeleton by the additional N-terminal proline-rich domain absent in GAPD-1. In this study we investigate the evolutionary history of GAPD and gain some insights into specialization of GAPD-2 as a testis-specific protein.</p> <p>Results</p> <p>A dataset of GAPD sequences was assembled from public databases and used for phylogeny reconstruction by means of the Bayesian method. Since resolution in some clades of the obtained tree was too low, syntenic analysis was carried out to define the evolutionary history of GAPD more precisely. The performed selection tests showed that selective pressure varies across lineages and isoenzymes, as well as across different regions of the same sequences.</p> <p>Conclusions</p> <p>The obtained results suggest that GAPD-1 and GAPD-2 emerged after duplication during the early evolution of chordates. GAPD-2 was subsequently lost by most lineages except lizards, mammals, as well as cartilaginous and bony fishes. In reptilians and mammals, GAPD-2 specialized to a testis-specific protein and acquired the novel N-terminal proline-rich domain anchoring the protein in the sperm tail cytoskeleton. This domain is likely to have originated by exonization of a microsatellite genomic region. Recognition of the proline-rich domain by cytoskeletal proteins seems to be unspecific. Besides testis, GAPD-2 of lizards was also found in some regenerating tissues, but it lacks the proline-rich domain due to tissue-specific alternative splicing.</p