138 research outputs found
Third and fourth degree collisional moments for inelastic Maxwell models
The third and fourth degree collisional moments for -dimensional inelastic
Maxwell models are exactly evaluated in terms of the velocity moments, with
explicit expressions for the associated eigenvalues and cross coefficients as
functions of the coefficient of normal restitution. The results are applied to
the analysis of the time evolution of the moments (scaled with the thermal
speed) in the free cooling problem. It is observed that the characteristic
relaxation time toward the homogeneous cooling state decreases as the
anisotropy of the corresponding moment increases. In particular, in contrast to
what happens in the one-dimensional case, all the anisotropic moments of degree
equal to or less than four vanish in the homogeneous cooling state for .Comment: 15 pages, 3 figures; v2: addition of two new reference
Optimizing Nozzle Geometry for Controlling Properties of Molecular Beam with Heavy Organic Molecules
Abstract. The flow in conical supersonic micronozzles and behind them by deposition of pentacene accelerated by helium was studied with the use of direct simulation Monte-Carlo method. The Knudsen number in critical cross-section of nozzles is 0.0043. A directedness of resulting accelerated pentacene flow was studied as a function of cone angle and geometrical Mach number of the nozzle. The intensity of heavy gas flow in the hypersonic region can be elevated by one order using supersonic nozzles
Non-Equilibrium Reaction Rates in the Macroscopic Chemistry Method for DSMC Calculations
The Direct Simulation Monte Carlo (DSMC) method is used to simulate the flow of rarefied gases. In the Macroscopic Chemistry Method (MCM) for DSMC, chemical reaction rates calculated from local macroscopic flow properties are enforced in each cell. Unlike the standard total collision energy (TCE) chemistry model for DSMC, the new method is not restricted to an Arrhenius form of the reaction rate coefficient, nor is it restricted to a collision cross-section which yields a simple power-law viscosity. For reaction rates of interest in aerospace applications, chemically reacting collisions are generally infrequent events and, as such, local equilibrium conditions are established before a significant number of chemical reactions occur. Hence, the reaction rates which have been used in MCM have been calculated from the reaction rate data which are expected to be correct only for conditions of thermal equilibrium. Here we consider artificially high reaction rates so that the fraction of reacting collisions is not small and propose a simple method of estimating the rates of chemical reactions which can be used in the Macroscopic Chemistry Method in both equilibrium and non-equilibrium conditions. Two tests are presented: (1) The dissociation rates under conditions of thermal non-equilibrium are determined from a zero-dimensional Monte-Carlo sampling procedure which simulates ‘intra-modal’ non-equilibrium; that is, equilibrium distributions in each of the translational, rotational and vibrational modes but with different temperatures for each mode; (2) The 2-D hypersonic flow of molecular oxygen over a vertical plate at Mach 30 is calculated. In both cases the new method produces results in close agreement with those given by the standard TCE model in the same highly nonequilibrium conditions. We conclude that the general method of estimating the non-equilibrium reaction rate is a simple means by which information contained within non-equilibrium distribution functions predicted by the DSMC method can be included in the Macroscopic Chemistry Method
Ингибитор ангиотензинпревращающего фермента в комплексном лечении ревматоидного а ртрита
Angiotensin-converting enzyme (ACE) inhibitors have anti-inflammatory and antiproliferative properties and can affect the processes of angiogenesis, by reducing the effects of angiotensin II (ATII). The use of ACE inhibitors in the combination therapy of rheumatoid arthritis (RA) can be also effective for monitoring disease activity and for reducing a cardiovascular risk.Objective: to evaluate the efficacy of an ACE inhibitor in the combination therapy of RA.Patients and methods. Eighty-four patients with RA and endothelial dysfunction were examined; the mean age was 40.12±10.2 years; the mean disease duration was 4.22±3.43 years. All the patients had a blood level of ATII of >9 pg/ml. Enzyme immunoassay was used to measure the levels of tumor necrosis factor-α (TNF-α) (Vector-Best, Russia), intercellular adhesion molecules 1 (ICAM-1) (Diaclone, France), vascular endothelial growth factor (VEGF) and ATII (Diagnostic, Canada). Wrist ultrasonography using the Doppler ultrasound apparatus ESAOTE MyLAB40 was carried out to assess synovial vascularization. The patients were divided into two groups. Group 1 included 43 patients who were assigned to receive standard therapy for RA according to the rheumatic disease treatment protocols; Group 2 comprised 41 patients who received the standard therapy plus ACE inhibitors 2.5–5 mg/day.Results. The use of ACE inhibitors in the 12-month combination therapy of RA patients led to an improvement in the endothelial regulation of vascular tone, to a decrease in the blood concentration of ICAM-1, to a reduction in the intensity of synovial angiogenesis and in the blood level of VEGF by 39%, and a more significant drop in the levels of CRP and TNF-? and in DAS28 by 1.2 scores as compared to those in the standard therapy.Ингибиторы ангиотензинпревращающего фермента (иАПФ) обладают противовоспалительными, антипролиферативными свойствами и могут влиять на процессы ангиогенеза через снижение эффектов ангиотензина II (АТІІ). Применение иАПФ в комплексной терапии ревматоидного артрита (РА) может быть эффективно и для контроля активности заболевания, и для снижения риска сердечно-сосудистых заболеваний.Цель исследования – оценка эффективности иАПФ в комплексной терапии РА.Пациенты и методы. Обследовано 84 больных РА с наличием эндотелиальной дисфункции, средний возраст – 40,12±10,2 года, средняя длительность РА – 4,22±3,43 года. У всех пациентов содержание АТІІ в крови составляло 9 пг/мл. С помощью иммуноферментного анализа определяли уровень фактора некроза опухоли α (ФНОα; «Вектор-Бест», Россия), молекул межклеточной адгезии (ICAM-1; Diaclone, Франция), сосудистого эндотелиального фактора роста (VEGF) и АТII (Diagnostic, Канада). Для оценки васкуляризации синовиальной оболочки (СО) выполняли УЗИ суставов кисти с допплером на аппарате ESAOTE MyLAB 40. Пациенты были разделены на две группы. В 1-ю группу вошли 43 пациента, которым была назначена стандартная терапия РА, согласно протоколам лечения ревматических заболеваний, во 2-ю группу – 41 пациент, получавший стандартную терапию с добавлением иАПФ 2,5–5 мг/сут.Результаты. Применение иАПФ в комплексной терапии больных РА в течение 12 мес приводило к улучшению показателей эндотелиальной регуляции сосудистого тонуса, снижению концентрации ICAM-1 в крови, уменьшению интенсивности ангиогенеза в СО и уровня VEGF в крови на 39%, более существенному снижению уровня СРБ, ФНОα и индекса активности DAS28 на 1,2 балла по сравнению с таковыми на фоне стандартной терапии
Качество жизни пациентов со спондилоартритами, получающих генно-инженерную биологическую терапию
Spondyloarthritides (SpAs) is a group of chronic inflammatory diseases of the spine, joints, and entheses characterized by common clinical, radiological, and genetic features. According to international guidelines, one of the main goals of SpA treatment is to ensure the longest possible preservation of the patient's quality of life (QOL). The use of biological agents (BAs) allows rapid clinical improvement and positively affects QOL in patients.Objective: to evaluate the efficacy of BAs on QOL in patients with SpA in real clinical practice.Patients and methods. A total of 280 patients with SpA were examined. The inclusion criteria were ≥18 years of age; compliance of the clinical picture of the disease with the ASAS criteria for axial SpA (2009) or peripheral SpA (2011); and signing the informed consent form. Disease activity was assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS); the functional status of the patients was estimated by the Bath Ankylosing Spondylitis Functional Index (BASFI), and their spinal mobility was evaluated by the Bath Ankylosing Spondylitis Metrology Index (BASMI); ASAS HI was used to comprehensively evaluate the impact of SpA on the patient's health. The European QL EQ-5D-5L and the SF-36 questionnaire were applied to determine quality of life in the patients.Results and discussion. The patients' mean age was 40.19±11.9 years; there was a male preponderance (64%); the HLA-B7-pisitive patients were 78%. The median scores were 5.40 [3.12; 6.80] for BASDAI, 3.37 [2.58; 4.15] for ASDAS, 5.30 [2.60; 7.50] for BASFI, 4.00 [2.60; 6.15] for BASMI, and 9.00 [7.00; 12.00] for ASAS HI. Forty-four patients received a variety of BAs. Patients receiving and not receiving BAs were matched for age and gender; however, the patients on biological therapy (BT) had longer disease duration and lower disease activity according to the ASDAS. There were no statistically significantly difference between the two groups in disease activity according to the BASDAI and in functional disorders according to the BASFI; but there was a tendency towards lower values in the patients on BT. Comparison of QOL in the patients of the two groups revealed statistically significant differences in SF-36 pain scale scores (p=0.02) and EQ-5D-5L indicators (p<0.01).Conclusion. BT makes it possible to successfully achieve one of the main goals of treating patients with SpA, namely to preserve QOL. The patients receiving BAs had longer disease duration, while they were comparable to those not receiving this treatment in terms of the degree of functional disorders.Спондилоартриты (СпА) – группа хронических воспалительных заболеваний позвоночника, суставов, энтезисов, характеризующихся общими клиническими, рентгенологическими и генетическими особенностями. Согласно международным рекомендациям, одной из основных целей лечения СпА является максимально долгое сохранение качества жизни (КЖ) пациента. Применение генно-инженерных биологических препаратов (ГИБП) позволяет обеспечить быстрое клиническое улучшение и положительно влияет на КЖ пациентов.Цель исследования – оценить влияние ГИБП на КЖ пациентов со СпА в реальной клинической практике.Пациенты и методы. Обследовано 280 пациентов со СпА. Критерии включения: возраст ≥18 лет, соответствие клинической картины заболевания критериям ASAS для аксиального (2009) или периферического (2011) СпА, подписание формы информированного согласия. Для оценки активности заболевания использовали индексы BASDAI и ASDAS, функционального статуса – BASFI, подвижности позвоночника – метрологический индекс BASMI, для комплексной оценки влияния СпА на здоровье пациента – ASAS HI. Для определения КЖ больных применяли европейский опросник оценки КЖ EQ-5D-5L и опросник SF-36.Результаты и обсуждение. Средний возраст пациентов составил 40,19±11,9 года, преобладали лица мужского пола (64%), позитивными по HLA-B27 были 78% больных. Медиана BASDAI – 5,40 [3,12; 6,80], ASDAS – 3,37 [2,58; 4,15], BASFI – 5,30 [2,60; 7,50], BASMI – 4,00 [2,60;6,15], ASAS HI – 9,00 [7,00; 12,00]. Различные ГИБП получали 44 больных. Пациенты, получавшие и не получавшие ГИБП, были сопоставимы по возрасту и полу, однако пациенты, находившиеся на генно-инженерной биологической терапии (ГИБТ), имели большую длительность и меньшую активность заболевания по данным индекса ASDAS. Активность заболевания по BASDAI, функциональные нарушения по BASFI у пациентов двух групп статистически значимо не различались, но наблюдалась тенденция к более низким показателям у больных, которым проводилась ГИБТ. При сравнении КЖ у пациентов двух групп выявлены статистически значимые различия в значениях шкалы «Боль» SF-36 (р=0,02) и показателях EQ-5D-5L (p<0,01).Выводы. ГИБТ позволяет успешно достигать одной из основных целей лечения пациентов со СпА – сохранения КЖ. Пациенты, получавшие ГИБП, имели большую длительность заболевания, при этом по степени функциональных нарушений они были сопоставимы с больными, которым такого лечения не проводили
Guidance on Noncorticosteroid Systemic Immunomodulatory Therapy in Noninfectious Uveitis: Fundamentals Of Care for UveitiS (FOCUS) Initiative
Topic: An international, expert-led consensus initiative to develop systematic, evidence-based recommendations for the treatment of noninfectious uveitis in the era of biologics. Clinical Relevance: The availability of biologic agents for the treatment of human eye disease has altered practice patterns for the management of noninfectious uveitis. Current guidelines are insufficient to assure optimal use of noncorticosteroid systemic immunomodulatory agents. Methods: An international expert steering committee comprising 9 uveitis specialists (including both ophthalmologists and rheumatologists) identified clinical questions and, together with 6 bibliographic fellows trained in uveitis, conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol systematic review of the literature (English language studies from January 1996 through June 2016; Medline [OVID], the Central Cochrane library, EMBASE, CINAHL, SCOPUS, BIOSIS, and Web of Science). Publications included randomized controlled trials, prospective and retrospective studies with sufficient follow-up, case series with 15 cases or more, peer-reviewed articles, and hand-searched conference abstracts from key conferences. The proposed statements were circulated among 130 international uveitis experts for review. A total of 44 globally representative group members met in late 2016 to refine these guidelines using a modified Delphi technique and assigned Oxford levels of evidence. Results: In total, 10 questions were addressed resulting in 21 evidence-based guidance statements covering the following topics: when to start noncorticosteroid immunomodulatory therapy, including both biologic and nonbiologic agents; what data to collect before treatment; when to modify or withdraw treatment; how to select agents based on individual efficacy and safety profiles; and evidence in specific uveitic conditions. Shared decision-making, communication among providers and safety monitoring also were addressed as part of the recommendations. Pharmacoeconomic considerations were not addressed. Conclusions: Consensus guidelines were developed based on published literature, expert opinion, and practical experience to bridge the gap between clinical needs and medical evidence to support the treatment of patients with noninfectious uveitis with noncorticosteroid immunomodulatory agents
Влияние лазерной коррекции на гидратную оболочку биоструктур клеток миокарда и печени при массивной кровопотере
Acute rat experiments have studied the impact of acute blood loss on the distribution of water fractions (total, free, and bound) in myocardial and hepatic tissues and whether detected impairments can be corrected by laser irradiation. They have provided an insight into the new pathogenetic mechanisms responsible for homeostatic disorders in blood loss and some aspects of the mechanism of action of laser emission on the body’s adaptive processes. The functioning of biopolymers and molecular structures in tissues is largely determined by their content of water. The redistribution of water towards to a blood loss-associated increase in bound water is a compensatory reaction aimed at preserving the biological structure of biopoly-mers. The decrease in hydrant-bound water suggests that there are severe derangements of their structure. The changes in the tissue free/bound water ratio reflect the degree of the body’s dysadaptation to blood loss. Laser irradiation has an adap-togenic effect on the structure of water in compensated hemorrhagic shock and a damaging action in decompensated one. В острых экспериментах на крысах изучено влияние острой кровопотери на распределение фракций воды (общей, свободной и связанной) в тканях миокарда и печени и возможность коррекции отмеченных нарушений лазерным излучением. Результаты экспериментов позволили раскрыть новые патогенетические механизмы нарушений гомеостаза при кровопотере и некоторые стороны механизма действия лазерного излучения на адаптивные процессы в организме. Показано, что функционирование биополимеров и молекулярных структур в тканях в значительной мере определяется содержанием в них воды. Перераспределение воды в сторону увеличения связанной при кровопотере является компенсаторной реакцией, направленной на сохранение биоструктуры биополимеров. Уменьшение гидратно связанной воды свидетельствует о глубоких нарушениях их структуры. Изменения в соотношении свободной и связанной воды в тканях отражает степень дезадаптации организма к кровопотере. Лазерное излучение оказывает адаптогенное действие на структуру воды при компенсированном геморрагическом шоке и повреждающее — при декомпенсированном
Recommended from our members
Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF
M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe
Approaches to the therapy of heart failure with reduced ejection fraction. Resolution of an online meeting of the Volga Federal District experts
At an online meeting of experts held on May 14, 2021 additional research results on a sodium-glucose co-transporter-2 (SGLT2) inhibitor empagliflozin in patients with heart failure with reduced ejection fraction were considered. According to the data from the EMPEROR-Reduced international study, cardiovascular and renal effects of empagliflozin therapy in patients with and without type 2 diabetes (T2D) were analyzed. A number of proposals and recommendations was accepted regarding the further study of cardiovascular and renal effects of empagliflozin and its use in clinical practice in patients with heart failure, regardless of the T2D presence
Prospective Catalytic Structured Converters for NH3-SCR of NOx from Biogas Stationary Engines: In Situ Template-Free Synthesis of ZSM-5 Cu Exchanged Catalysts on Steel Carriers
- …