93 research outputs found
Horndeski Genesis: strong coupling and absence thereof
We consider Genesis in the Horndeski theory as an alternative to or
completion of the inflationary scenario. One of the options free of
instabilities at all cosmological epochs is the one in which the early Genesis
is naively plagued with strong coupling. We address this issue to see whether
classical field theory description of the background evolution at this early
stage is consistent, nevertheless. We argue that, indeed, despite the fact that
the effective Plank mass tends to zero at early time asymptotics, the classical
analysis is legitimate in a certain range of Lagrangian parameters.Comment: 10 pages, 1 figur
INVESTIGATION OF SORPTION CHARACTERISTICS OF POLYMERIC MINERAL-FILLED COMPOSITES FOR MEDICINE
The polymer compositions on the base of acrylic derivatives and bentonite particles modified by silver ions with various share and dispersion are received and studied by radical polymerization in the water. Partially neutralized acrylic acid, acrylamide and methylene-bis-acrilamide and particles of bentonite with fraction 0 - 0,05 mass.% are chosen as initial substances. The influence of bentonite concentration on absorbing characteristics of polymer materials in the distilled water is shown. It is demonstrated that the increase of bentonite fraction up to 5 mass.% leads to the rise of degree of equilibrium swelling by 1,5 – 2 times in comparison with an unfilled polymer matrix. The acrylic nanocompositions with a mass fraction of bentonite equal to 0,01 mass.% possess the greatest kinetic characteristics. Kinetic dependences of new composite materials swelling in physiological solution from a filler dispersion part are investigated. It is shown that in high dispersion (with particle size less than 0,25 mm) a part of mineral–containing filler equal to 1 mass.% leads to significant increase in values of equilibrium swelling degree in comparison with an unfilled sample (by 1,5 times). The effect of polyelectrolyte suppression of polymer composition swelling in physiological solution is studied. It results in values reduction of equilibrium swelling degree in comparison with these values in the distilled water. Application prospects for the received compositions are shown at bandages creation for wounds treatment of various etiologies. Research results are recommended for usage in medical practice for optimization of wound process march
К вопросу о назначении дополнительных остановок пассажирским поездам дальнего следования в границах города Москвы
In many world’s most populous cities, railways are an integral part of urban transport systems. Commuter and intraurban passenger railway traffic is often and widely considered in this context. On the other hand, the constant growth in passenger traffic of longdistance trains, traditionally gravitating towards railway stations and adjacent urban transport hubs, including metro stations through which arriving passengers pass towards their final destinations in the city, requires search for new solutions to improve comfort of the trip for passengers, and to remove the excess load from the urban transit system. Considering the experience and features of organization of long-distance passenger railway traffic in various countries, the authors based on previous research suggests certain solutions regarding Moscow railway hub. To organize comfortable environment for passengers of all categories of trains, it is advisable to develop a balanced technology of train traffic within the Moscow junction, excluding overloading of individual elements of the transport system (in particular, of rail stations in the city center). The objective of the article is to analyze global experience in organizing traffic of long-distance passenger trains within the boundaries of large agglomerations and to develop proposals to organize additional stopping points for long-distance trains in various districts of Moscow, which will help reduce the load on central transport and interchange hubs, improve quality of transportation services for passengers, and develop the districts of Moscow and Moscow region adjacent to the new TIHs.Во многих крупных городах мира железные дороги являются неотъемлемым элементом городских транспортных систем. Наиболее часто и широко рассматриваются в этом контексте пригородное и внутригородское пассажирское железнодорожное движение. С другой стороны, постоянный рост пассажиропотоков поездов дальнего следования, традиционно тяготеющих к железнодорожным вокзалам и прилегающим к ним городским транспортным узлам, в том числе станциям метро, через которые прибывающие пассажиры отправляются к конечным точкам назначения в городе, требует поиска новых решений, позволяющих как повысить комфортность поездки для пассажиров, так и снять избыточную нагрузку с городской транспортной системы. С учётом опыта и специфики организации дальнего пассажирского железнодорожного сообщения в различных странах, в статье на основе ранее проведённых исследований, в первую очередь, предлагаются модели решений для московского железнодорожного узла, который является сложным транспортным комплексом. С целью организации комфортных условий для пассажиров всех категорий поездов необходимо разработать сбалансированную технологию движения поездов в узле, исключающую перегрузку отдельных элементов транспортной системы (в частности, вокзалов в центре города). Целью данной статьи является анализ зарубежного опыта организации движения пассажирских поездов дальнего следования в границах крупных агломераций и выработка предложений по организации дополнительных остановочных пунктов поездам дальнего следования в различных районах Москвы, которые помогут снизить нагрузку на центральные транспортно-пересадочные узлы, повысить качество транспортного обслуживания пассажиров и вместе с тем развить прилегающие к новым транспортно-пересадочным узлам районы Москвы и Московской области
Hyperbaric Oxygen Therapy in Patients with COVID-19
The aim of the study is to evaluate the efficacy of hyperbaric oxygen therapy and its effect on oxidative stress and apoptosis in patients with new coronavirus infection COVID-19.Materials and methods. 90 patients diagnosed with new coronavirus infection caused by SARS-CoV-2 virus were examined. Hyperbaric oxygen therapy sessions were conducted in 57 patients (38 in severe condition (CT 3-4), 19 in moderate condition (CT 1-2)). The procedures were performed in 1.4-1.6 ATA mode for 40 minutes, 247 sessions in total were performed. The effect of hyperbaric oxygenation was assessed by measuring the level of oxygen saturation, the severity of oxidative stress and apoptosis of blood lymphocytes.Results. In all examined patients with new coronavirus infection caused by SARS-CoV-2, positive changes such as dyspnea reduction and improvement of general well-being were registered after hyperbaric oxygen therapy sessions. The level of oxygen saturation after the end of the hyperbaric oxygen therapy course was 95.0±1.6% (before the course — 91.3±5.9%), which allowed to return almost all patients to spontaneous respiration without the need for further oxygenation therapy. Hyperbaric oxygen therapy did not reduce the total antioxidant activity, however, it was associated with a decrease in the blood malone dialdehyde from 4.34±0.52 pmol/l to 3.98±0.48 pmol/l and a decrease in open circuit potential of platinum electrode from -22.78±24.58 mV to -37.69±17.4 mV. Besides, the positive effect of hyperbaric oxygen therapy was manifested in normalization of blood cell apoptosis.Conclusion. Hyperbaric oxygen therapy in patients with new coronavirus infection caused by the SARS-CoV-2 virus is an effective treatment method with multiple effects resulting in improvement of subjective indicators of the patients' condition, increase of hemoglobin oxygen saturation, decrease of lipid peroxidation intensity, activation of antioxidant system, restoration of pro- and antioxidant balance and apoptosis normalization
Induced pseudoscalar coupling of the proton weak interaction
The induced pseudoscalar coupling is the least well known of the weak
coupling constants of the proton's charged--current interaction. Its size is
dictated by chiral symmetry arguments, and its measurement represents an
important test of quantum chromodynamics at low energies. During the past
decade a large body of new data relevant to the coupling has been
accumulated. This data includes measurements of radiative and non radiative
muon capture on targets ranging from hydrogen and few--nucleon systems to
complex nuclei. Herein the authors review the theoretical underpinnings of
, the experimental studies of , and the procedures and uncertainties
in extracting the coupling from data. Current puzzles are highlighted and
future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
Эффекты ксенона в отношении маркеров нейровоспаления. Проспективное пилотное исследование
The leading role of neuroinflammation as the culprit of a long-term impairment of consciousness in patients after injuries to the central nervous system forces us to look for new effective strategies for resolving this pathological process. Xenon reducing the intensity of the inflammatory response due to the impact on several links is potentially able to have a beneficial effect on this category of patients. Using laboratory equipment, we evaluated the effect of half-hour daily inhalations of a 30% air mixture with 30% xenon for 7 days on the level of markers of neuronal damage and regeneration of nervous tissue.AIM To study the effect of inhalation of an air-xenon mixture on the dynamics of markers of neuroinflammation and restoration of nervous tissue in patients after traumatic brain injury (TBI).MATERIAL AND METHODS We conducted a prospective randomized clinical trial evaluating the effect of inhaled xenon for sedation on the level of consciousness and spasticity in patients with prolonged post-coma impairment of consciousness. Patients were randomized into 2 equal groups. In Group I (Comparison, n=15) in addition to the standard treatment for TBI, each patient included in the study underwent 7 sessions of inhalation of an air mixture with an oxygen content of at least 30 vol.% for 30 minutes. In Group II (Xenon, n=15) in addition to the standard treatment, each patient included in the study underwent a half-hour inhalation with an air-xenon gas mixture (with a xenon content of 30 vol.% and oxygen — 30 vol.%) for 7 days, 1 time per day. The levels of interleukin-6, α-1 acid glycoprotein (AGP), S100 b protein and brain-derived neurotrophic factor were assessed before the first treatment and then once a day for 6 days.RESULTS The final evaluation included 12 patients from the Comparison Group and 12 patients from the Xenon Group. The greatest difference in the concentration of interleukin-6 between the Comparison and Xenon Groups was noted on the 5th day - 12.31 (10.21; 15.43) pg/ml vs. 7.93 (3.61; 9.27) pg/ml, respectively; however, the findings only tended to be statistically significant (p=0.07). When assessing the AGP level, the maximum difference was noted on the 4th day. In the Comparison Group, the AGP level was 0.81 (0.74; 0.92) pg/ml versus 0.614 (0.4; 0.79) pg/ml in the Xenon Group. And again, the data showed only a trend towards statistical significance (p=0.09). The highest level of brain-derived neurotrophic factor in the Xenon Group was observed on the 3th day — 0.1271 (0.046; 0.2695) pg/ml, which was statistically significantly higher than the one in the Comparison Group — 0.062 (0.036; 0.121) pg/ml (p=0.04). The concentration of S100 b protein during the entire observation period in both groups did not exceed 0.005 pg/ml.CONCLUSION Xenon inhalation according to the method proposed by the authors had a beneficial effect on the processes of neural tissue regeneration, however, with regard to neuroinflammation, its effects were not so pronounced.Ведущая роль нейровоспаления как виновника длительного нарушения сознания у пациентов после травм центральной нервной системы вынуждает искать новые эффективные стратегии разрешения данного патологического процесса. Эффекты ксенона, позволяющие снизить интенсивность воспалительной реакции за счет воздействия на несколько звеньев, потенциально способны оказать благотворное влияние на данную категорию пациентов. В рамках лабораторной диагностики мы оценили влияние получасовых ежедневных ингаляций 30% воздушной смеси с 30% содержанием ксенона в течение 7 дней на уровень маркеров нейронального повреждения и регенерации нервной ткани.ЦЕЛЬ Изучить влияние ингаляции воздушно-ксеноновой смеси на динамику маркеров нейровоспаления и восстановления нервной ткани у пациентов после черепно-мозговой травмы (ЧМТ).МАТЕРИАЛ И МЕТОДЫ Было проведено проспективное рандомизированное клиническое исследование влияния ингаляционной седации ксеноном на уровень сознания и спастической активности у пациентов с посткоматозными длительными нарушениями сознания. Пациенты были рандомизированы на 2 равные по числу участников группы. В группе I (сравнения, n=15) — помимо стандартного лечения после ЧМТ, каждому включенному в исследование пациенту были проведены 7 сеансов ингаляций воздушной смеси с содержанием кислорода не менее 30 об% в течение 30 минут. Группе II (исследования, n=15) — помимо стандартного лечения каждому включенному в исследование пациенту проводилась получасовая ингаляция воздушно-ксеноновой газовой смесью (с содержанием ксенона 30 об% и кислорода 30 об%) на протяжении 7 дней 1 раз в сутки. Оценка уровней интерлейкина-6, α-1 кислого гликопротеина (AGP), белка S100 b и нейротрофического фактора мозга производилась до начала первой процедуры и далее 1 раз в сутки на протяжении 6 дней.РЕЗУЛЬТАТЫ В конечную оценку вошли 12 пациентов из группы сравнения и 12 пациентов из исследовательской группы. Наибольшая разница в концентрации интерлейкина-6 между группами сравнения и ксенона отмечалась на 5-е сутки — 12,31 (10,21; 15,43) против 7,93 (3,61; 9,27) пг/мл соответственно, однако полученные данные обладали только тенденцией к статистической значимости (p=0,07). При оценке уровня AGP максимальная разница отмечалась на 4-е сутки. В группе сравнения уровень AGP составлял 0,81 (0,74; 0,92) пг/мл против 0,614 (0,4; 0,79) в группе ксенона. Данные также демонстрировали только тенденцию к статистической значимости (p=0,09). Наиболее высокий уровень нейротрофического фактора мозга в группе ксенона отмечался на 3-и сутки — 0,1271 (0,046; 0,2695) пг/мл, что было статистически значимо выше уровня в группе сравнения — 0,062 (0,036; 0,121) пг/мл (p=0,04). Концентрация белка S100 b на протяжении всего периода наблюдения в обеих группах на превышала 0,005 пг/мл.ЗАКЛЮЧЕНИЕ Ингаляция ксеноном по предложенной нами методике оказала благотворное влияние на процессы регенерации нервной ткани, однако в отношении нейровоспаления эффекты были не столь выраженными
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