Analytical theory of forced rotating sheared turbulence: The parallel case

Forced turbulence combined with the effect of rotation and shear flow is studied. In a previous paper [N. Leprovost and E. J. Kim, Phys. Rev. E 78, 016301 (2008)], we considered the case where the shear and the rotation are perpendicular. Here, we consider the complementary case of parallel rotation and shear, elucidating how rotation and flow shear influence the generation of shear flow (e.g., the direction of energy cascade), turbulence level, transport of particles, and momentum. We show that turbulence amplitude and transport are always quenched due to strong shear (ξ=νky2∕A⪡1, where A is the shearing rate, ν is the molecular viscosity, and ky is a characteristic wave number of small-scale turbulence), with stronger reduction in the direction of the shear than those in the perpendicular directions. In contrast with the case where rotation and shear are perpendicular, we found that rotation affects turbulence amplitude only for very rapid rotation (Ω⪢A) where it reduces slightly the anisotropy due to shear flow. Also, concerning the transport properties of turbulence, we find that rotation affects only the transport of particle and only for rapid rotation, leading to an almost isotropic transport (whereas, in the case of perpendicular rotation and shear, rotation favors isotropic transport even for slow rotation). Furthermore, the interaction between the shear and the rotation is shown to give rise to nondiffusive flux of angular momentum (Λ effect), even in the absence of external sources of anisotropy, which can provide a mechanism for the creation of shearing structures in astrophysical and geophysical systems

Analytical theory of forced rotating sheared turbulence: The perpendicular case

Rotation and shear flows are ubiquitous features of many astrophysical and geophysical bodies. To understand their origin and effect on turbulent transport in these systems, we consider a forced turbulence and investigate the combined effect of rotation and shear flow on the turbulence properties. Specifically, we study how rotation and flow shear influence the generation of shear flow (e.g., the direction of energy cascade), turbulence level, transport of particles and momentum, and the anisotropy in these quantities. In all the cases considered, turbulence amplitude is always quenched due to strong shear (ξ=νky2/A⪡1, where A is the shearing rate, ν is the molecular viscosity, and ky is a characteristic wave number of small-scale turbulence), with stronger reduction in the direction of the shear than those in the perpendicular directions. Specifically, in the large rotation limit (Ω⪢A), they scale as A−1 and A−1|ln ξ|, respectively, while in the weak rotation limit (Ω⪡A), they scale as A−1 and A−2/3, respectively. Thus, flow shear always leads to weak turbulence with an effectively stronger turbulence in the plane perpendicular to shear than in the shear direction, regardless of rotation rate. The anisotropy in turbulence amplitude is, however, weaker by a factor of ξ1/3|ln ξ| (∝A−1/3|ln ξ|) in the rapid rotation limit (Ω⪢A) than that in the weak rotation limit (Ω⪡A) since rotation favors almost-isotropic turbulence. Compared to turbulence amplitude, particle transport is found to crucially depend on whether rotation is stronger or weaker than flow shear. When rotation is stronger than flow shear (Ω⪢A), the transport is inhibited by inertial waves, being quenched inversely proportional to the rotation rate (i.e., ∝Ω−1) while in the opposite case, it is reduced by shearing as A−1. Furthermore, the anisotropy is found to be very weak in the strong rotation limit (by a factor of 2) while significant in the strong shear limit. The turbulent viscosity is found to be negative with inverse cascade of energy as long as rotation is sufficiently strong compared to flow shear (Ω⪢A) while positive in the opposite limit of weak rotation (Ω⪡A). Even if the eddy viscosity is negative for strong rotation (Ω⪢A), flow shear, which transfers energy to small scales, has an interesting effect by slowing down the rate of inverse cascade with the value of negative eddy viscosity decreasing as |νT|∝A−2 for strong shear. Furthermore, the interaction between the shear and the rotation is shown to give rise to a nondiffusive flux of angular momentum (Λ effect), even in the absence of external sources of anisotropy. This effect provides a mechanism for the existence of shearing structures in astrophysical and geophysical systems

Structural dependence of CsI(Tl) film scintillation properties

Scintillating CsI(Tl) films were obtained by vacuum deposition on single crystalline LiF substrates and non-orienting glass substrates. Their structure and morphology were examined by X-ray diffraction and scanning electron microscopy. Scintillation properties of films dependent on their structure are discussed

Предварительные результаты включения меглюмина натрия сукцината в лечение пациентов с острым панкреатитом средней и тяжелой степени

Objective: to develop criteria of inclusion/noninclusion of patients for further randomized clinical trial of meglumine sodium succinate in patients with acute pancreatitis based on analysis of individual outcomes.Material and methods. The efficacy of treatment of patients with moderate-to-severe and severe acute pancreatitis (n=100, 23–65 years old) with meglumine sodium succinate (intravenous drip infusions, 10 ml/kg daily, for 11 days) was assessed. Data were collected by 10 medical centers as a part of an observational program developed in accordance with the requirements of the Guidelines and Clinical Trial Committee of the AllRussia Public Organization «Federation of Anesthesiologists and Reanimatologists» (FAR) and approved by local ethical committees of the institutions. Treatment was prescribed in accordance with national and international standards. The patients were divided into two groups based on the outcome: group 1 (n=81) included patients who survived, while the patients of group 2 (n=19) died. We analyzed demographic characteristics of the groups, life and illness history, physical examination, routine laboratory and instrumental investigation data. The obtained results were statistically analyzed.Results. We identified several factors occurring during hospitalization and/or transfer to intensive care unit (ICU), which could be predictors of adverse outcome and had varying impact on the risk of death in patients treated with the study drug. High-risk factors included stupor, platelet count below 248.5×109/l, base excess (BE) less than -2.9 mmol/l, and urea above 11.85 mmol/l. Risk factors included body temperature below 37.1°C, plasma creatinine above 237 µmol/l, and glucose above 9.45 mmol/l. Mottled skin and plasma ionized calcium levels below 1.13 mmol/l were considered probable risk factors.Conclusion. Determined prognostically significant predictors of adverse outcome in patients with acute pancreatitis receiving Reamberin should be considered when selecting inclusion/exclusion criteria for the randomized controlled comparative clinical study of the efficacy of meglumine sodium succinate in patients with acute pancreatitis.Цель. На основе анализа индивидуальных исходов заболевания выявить критерии включения/невключения пациентов для последующего проведения рандомизированного клинического исследования эффективности меглюмина натрия сукцината у больных с острым панкреатитом.Материал и методы. Провели анализ эффективности лечения 100 пациентов в возрасте 23–65 лет с острым панкреатитом среднетяжелого и тяжелого течения, получавших меглюмина натрия сукцинат в составе инфузий внутривенно капельно в средней суточной дозе 10 мл/кг продолжительностью до 11 дней. Сбор данных проводили десять медицинских центров в рамках наблюдательной программы по протоколу, одобренному Комитетом по рекомендациям и организации исследований Общероссийской общественной организации «Федерация анестезиологов и реаниматологов» и локальными этическими комитетами учреждений. Лечение проводили в соответствии с национальными и международными стандартами. С учетом исхода заболевания больных разделили на две группы: группа 1 (n=81) — выжили, группа 2 (n=19) — летальный исход. Проанализировали демографическую характеристику групп, анамнез жизни, болезни, данные объективного осмотра, стандартных лабораторных и инструментальных исследований. Полученные результаты статистически обработали.Результаты и обсуждение. Выделили ряд факторов при госпитализации и/или при переводе в отделение реанимации и интенсивной терапии (ОРИТ), которые могут быть предикторами неблагоприятного исхода и в разной степени влиять на риск смерти пациентов, получавших при данном заболевании инфузию и изучаемый препарат. К факторам высокого риска отнесли наличие сопора, содержание тромбоцитов ниже 248,5×109/л, Base Excess менее -2,9 ммоль/л, содержание мочевины выше 11,85 ммоль/л. К факторам риска отнесли температуру тела ниже 37,1°С, содержание в плазме креатинина выше 237 мкмоль/л и глюкозы — выше 9,45 ммоль/л. К вероятным факторам риска отнесли мраморность кожных покровов и содержание ионизированного кальция в плазме крови ниже 1,13 ммоль/л.Заключение. Получили предварительные данные для формирования критериев включения/невключения рандомизированного контрольно-сравнительного клинического исследования эффективности меглюмина натрия сукцината у больных острым панкреатитом

Trabectedin plus pegylated liposomal doxorubicin in relapsed ovarian cancer delays third-line chemotherapy and prolongs the platinum-free interval

Background: OVA-301 is a large randomized trial that showed superiority of trabectedin plus pegylated liposomal doxorubicin (PLD; CentoCor Ortho Biotech Products L.P., Raritan, NJ, USA). over single-agent PLD in 672 patients with relapsed ovarian cancer, particularly in the partially platinum-sensitive subgroup [platinum-free interval (PFI) of 6–12 months]. This superiority has been suggested to be due to the differential impact of subsequent (platinum) therapy

Влияние отмены ИАПФ/БРА на риск развития послеоперационных осложнений в абдоминальной хирургии

A significant proportion of patients undergoing non-cardiac surgery receive therapy with angiotensin converting enzyme (ACE) inhibitors/angiotensin II receptor blockers (ARBs), which are usually prescribed for treatment of arterial hypertension and CHF. Current guidelines fail to provide clear consensus on whether it is worth discontinuing ACEi/ARBs before non-cardiac surgery. The aim of this research was to assess the contribution of pre-op ACEi/ARBs withdrawal to the development of postoperative complications in patients after abdominal surgery using data from STOPRISK database.Materials and methods. Data of 1945 patients from of the STOPRISK database was used for the analysis. Patients were retrospectively divided into two groups: first group (N=471, 24.2%) included patients subjected to ACEi/ARBs withdrawal 24 hours before surgery, second group (N=1474, 75.8%) included patients continuing on ACEi/ARBs therapy. The 30-day outcomes were analyzed — postoperative complications (acute kidney injury, acute respiratory distress syndrome, anastomosis failure, arrhythmias, circulatory arrest, cardiogenic pulmonary edema, postoperative delirium, myocardial infarction, pneumonia, ileus, postoperative bleeding, pulmonary embolism, acute cerebrovascular accident, wound infection) and mortality. We were not evaluating intraoperative and postoperative arterial hypotension and hypertension, we analyzed the use of vasopressors as a surrogate marker. ACEi/ARBs re-initiation after surgery was not evaluated.Results. One or more post-operative complications were documented in 113 patients (5.8%). Only postoperative delirium was more common in patients (1.06% vs. 0.27%, P=0.027) after ACEi/ARBs withdrawal 24 hours before surgery, the difference reached statistical significance. Sub-analysis in the group of patients with arterial hypertension as the only comorbidity showed no statistically significant differences in the outcomes. Sub-analysis in the group of patients with CFH showed higher incidence of postoperative delirium after ACEi/ARBs withdrawal (2.68% vs. 0.6%, P=0.023). The logistic regression analysis showed that the risk of developing postoperative delirium is influenced by age, vasopressor support, and ACEi/ARBs withdrawal (the area under the curve for the model was 0.92 (0.90–0.93).Conclusion. Rates of pre-op ACEi/ARBs withdrawal (24.2%) are consistent with published data. In the entire cohort, ACEi/ARBs withdrawal resulted in higher incidence of postoperative delirium, as well as in the subgroup of patients with CHF, while ACEi/ARBs withdrawal in the subgroup of patients with arterial hypertension had no influence on postop complications.ACEi/ARBs withdrawal, along with hemodynamic instability and older age, contributes to the development of postoperative delirium, which is the subject of future research. Значительное число пациентов, подвергающихся внесердечным операциям, получает терапию ингибиторами ангиотензинпревращающего фермента (ИАПФ)/блокаторами рецепторов ангиотензина II (БРА), которые обычно назначают в качестве антигипертензивных препаратов и для лечения ХСН. В современных руководствах нет единого мнения о том, стоит ли отменять ИПФ/БРА перед внесердечными операциями.Цель работы — изучение вклада отмены ИАПФ/БРА в развитие послеоперационных осложнений у пациентов в абдоминальной хирургии по данным базы STOPRISK.Методы исследования. В анализ включили данные 1945 пациентов базы данных STOPRISK, которых ретроспективно разделили на пациентов, у которых ИАПФ/БРА отменяли за 24 ч до операции (n=471, 24,2%) и остальных пациентов (n=1474, 75,8%), у которых прием продолжался вплоть до оперативного вмешательства. Изучали 30-дневный исход — послеоперационные осложнения (острое повреждение почек, острый респираторный дистресс-синдром, несостоятельность анастомоза, аритмии, остановка кровообращения, кардиогенный отек легких, послеоперационный делирий, инфаркт миокарда, пневмония, парез кишечника, послеоперационное кровотечение, тромбоэмболия легочной артерии, острое нарушение мозгового кровообращения, раневая инфекция) и летальность. В исследовании не оценивали частоту интраоперационной и послеоперационной гипотензии и гипертензии, применяли суррогатный показатель — частоту применения вазопрессоров. Не оценивали возобновление терапии ИАПФ/БРА в послеоперационный период Результаты. Наличие одного и более осложнения регистрировали у 113 пациентов (5,8%). Статистически значимыми были различия только в частоте послеоперационного делирия — он чаще встречался в группе пациентов, у которых ИАПФ/БРА отменяли за 24 часа до операции (1,06% против 0,27%, р=0,027). При проведении субанализа в подгруппе пациентов, где сопутствующие заболевания были представлены изолированной гипертонической болезнью, статистически значимых различий в исходах не отметили.Субанализ у пациентов, в структуре сопутствующих заболеваний которых присутствовала хроническая сердечная недостаточность, показал большую частоту послеоперационного делирия в группе пациентов, у которых ИАПФ/БРА отменяли (2,68% против 0,6%, р=0,023).Проведенный логистический регрессионный анализ показал, что на риск развития послеоперационного делирия влияют возраст, вазопрессорная поддержка, отмена ИАПФ/БРА (площадь под кривой для модели составила 0,92 (0,90–0,93).Заключение. Частота отмены ИАПФ/БРА (24,2%) соотносится с мировыми данными. В общей когорте отмена ИАПФ/БРА приводила к большей частоте развития послеоперационного делирия, субанализ в группе пациентов с хронической сердечной недостаточностью подтвердил эту закономерность, в группе же пациентов с гипертонической болезнью, отмена ИАПФ/БРА, не влияла на исход. Наряду с гемодинамической нестабильностью и пожилым возрастом, отмена ИАПФ/БРА, вносит вклад в развитие послеоперационного делирия, что требует дальнейшего изучения.

CsI(TI) films: deposition, examination of structure and scintillation

The sublimation of the bulk CsI crystal with optimal activator concentration istead of powder source use at vacuum deposition of CsI(TI) films has been shown to provide CsI(TI) films with required content and uniform distribution of activator in the film volume. The CsI(TI) film produced by this technology demonstrate superior scintillation characteristics in comparison with CsI(TI) film deposited by a usual technology. The dependence of the film crystalline structure on the deposition conditions has been studied in detail