Effects of Turbulent Mixing on the Critical Behavior

Effects of strongly anisotropic turbulent mixing on the critical behavior are studied by means of the renormalization group. Two models are considered: the equilibrium model A, which describes purely relaxational dynamics of a nonconserved scalar order parameter, and the Gribov model, which describes the nonequilibrium phase transition between the absorbing and fluctuating states in a reaction-diffusion system. The velocity is modelled by the d-dimensional generalization of the random shear flow introduced by Avellaneda and Majda within the context of passive scalar advection. Existence of new nonequilibrium types of critical regimes (universality classes) is established.Comment: Talk given in the International Bogolyubov Conference "Problems of Theoretical and Mathematical Physics" (Moscow-Dubna, 21-27 August 2009

Effects of turbulent mixing on critical behaviour in the presence of compressibility: Renormalization group analysis of two models

Critical behaviour of two systems, subjected to the turbulent mixing, is studied by means of the field theoretic renormalization group. The first system, described by the equilibrium model A, corresponds to relaxational dynamics of a non-conserved order parameter. The second one is the strongly non-equilibrium reaction-diffusion system, known as Gribov process and equivalent to the Reggeon field theory. The turbulent mixing is modelled by the Kazantsev-Kraichnan "rapid-change" ensemble: time-decorrelated Gaussian velocity field with the power-like spectrum k^{-d-\xi}. Effects of compressibility of the fluid are studied. It is shown that, depending on the relation between the exponent \xi and the spatial dimension d, the both systems exhibit four different types of critical behaviour, associated with four possible fixed points of the renormalization group equations. The most interesting point corresponds to a new type of critical behaviour, in which the nonlinearity and turbulent mixing are both relevant, and the critical exponents depend on d, \xi and the degree of compressibility. For the both models, compressibility enhances the role of the nonlinear terms in the dynamical equations: the region in the d-\xi plane, where the new nontrivial regime is stable, is getting much wider as the degree of compressibility increases. In its turn, turbulent transfer becomes more efficient due to combined effects of the mixing and the nonlinear terms.Comment: 25 pages, 4 figure

The perspective soft spring wheat variety Semenovna is the result of international cooperation

The research is aimed at studying economically valuable traits and genetic control of resistance to leaf-stem diseases, photoperiodic reaction and short stemming of soft spring wheat variety Semenovna, created by scientists of the Omsk Agrarian Scientific Center (Russia) and the North Kazakhstan Agricultural Experimental Station (Kazakhstan). Using methods of state variety testing, molecular genetics and in vitro methods, morphological features of a new variety, features of its development have been described, the yield level at different ecological test points for three years (2015-2017) has been analyzed. The studies conducted at two ecological points made it possible to select a medium-sized promising line of soft spring wheat (Lutescens 354/04-6), which was transferred to the State Registration Service of the Republic of Kazakhstan and after two years of testing was included into the State Register of the Republic of Kazakhstan under the name Semenovna (patent No. 1023). In terms of grain quality, it was at the level of valuable wheat, exceeded the standard in protein content by 1-2 % and raw gluten by 3-4 %. The new medium-ripe Semenovna variety combines increased yield (2.73-4.40 t/ha) with resistance to drought (resistance index Ir = 0.57), brown and stem rust (IU = 0.00-0.23). The genotype of the variety contains wheat-rye translocation 1RS.1BL (with a cluster of Lr26/Sr31/Pm8/Yr9 genes). The medium-stem variety carries the Rht8b allele in its genotype (174 bp)  and is photosensitive to the length of the day (allele 414 bp). The parameters of ecological plasticity of the new variety are determined: linear regression coefficient (bi = 1.08), stability index (σd2 = 0.27)

Изучение структурных особенностей соединительной ткани век у пациентов с первичной открытоугольной глаукомой

PURPOSE: To study collagen structures of periorbital tissues of patients with primary open-angle glaucoma (POAG). METHODS: During the surgeries of 12 patients aged 55-87, 17 samples of various tissues were taken: 13 eyelid skin samples of 8 patients during blepharoplasty, 3 cartilage samples during eyelid eversion surgery, 1 sample of sclera during nonpenetrating deep sclerotomy. In total, 7 samples were obtained from patients with stages II and III of POAG and 10 samples from patients without glaucoma. We measured the endothermic temperature peak (Td) and enthalpy ΔHd) of denaturation process using differential scanning calorimetry (Phoenix DSC 204, «Netzsch», Germany) to estimate the crosslinking level of the examined tissues. RESULTS: ΔHd and Td medians of eyelid skin samples of patients aged 55-60 (median - 57 years) without POAG were equal to 7.03 J/g of dry weight and 66.600С, respectively. In contrast, patients of an older age group - 72-79 years (median - 75 years) revealed higher values of this parameter: 9.12 J/g of dry weight and 67.25°С. Moreover, the patients of the same age group (median - 74 years) with POAG showed even higher values of these parameters: 9.33 J/g of dry weight and 67.35°С, respectively. Thermomechanical parameters of eyelid cartilage of same age patients (71-78 years) were different in POAG/No POAG cases: 8.26 J/g of dry weight and 66.6°С, and 10.106 J/g of dry weight and 67,1°С respectively. A clinical case of a metabolic disorder of eyelid connective tissue and sclera is presented: a 72-year old patient K. with stage II POAG in OD and stage III POAG in OS and initial cataract of OU. ΔHd and Тd of OD eyelid skin (9.97 J/g of dry weight and 66.3°С) were lower than in OS (13.1 J/g of dry weight and 66.4°С). ΔHd and Тd of the OS sclera were 4.8 J/g of dry weight and 65.9°С. After glaucoma surgery in OS, excessive scarring along newly formed outflow paths was noted. CONCLUSION: A clear age-related rising trend of collagen crosslinking level and collagen content increase in eyelid tissues (skin and cartilage) was revealed. Respective parameters in POAG patients were higher than in patients of the same age group without glaucoma.ЦЕЛЬ. Изучение особенностей коллагеновых структур тканей придаточного аппарата глаза у пациентов с первичной открытоугольной глаукомой (ПОУГ). МЕТОДЫ. У 12 пациентов в возрасте от 55 до 87 лет в ходе хирургических вмешательств были взяты 17 образцов различных тканей: 13 образцов кожи век 8 пациентов при блефаропластических операциях, 3 образца хряща 3 пациентов при устранении выворота века, 1 образец склеры у 1 пациента при непроникающей глубокой склерэктомии. У пациентов с ПОУГ II и III стадий взяты 7 образцов тканей и 10 фрагментов - у пациентов без глаукомы. Для оценки уровня поперечной связанности коллагена определяли термомеханические показатели образцов исследуемых тканей - эндотермический температурный пик (Тд) и энтальпию (ΔHд) процесса денатурации с помощью дифференциальной сканирующей калориметрии (Phoenix DSC 204, «Netzsch», Германия). РЕЗУЛЬТАТЫ. Медианы ΔHд и Тд образцов кожи век пациентов в возрасте 55-60 лет (медиана - 57 лет) без ПОУГ составляли 7,03 Дж/г сухого веса и 66,60°С соответственно. В то же время у пациентов более старшей возрастной группы - 72-79 лет (медиана - 75 лет) без ПОУГ эти показатели были выше: 9,12 Дж/г сухого веса и 67,25°С. У пациентов с ПОУГ той же возрастной группы (медиана - 74 года) эти показатели были еще выше - 9,33 Дж/г сухого веса и 67,35°С соответственно. Термомеханические показатели хряща век пациентов близкого возраста (71-78 лет) без ПОУГ и с ПОУГ также оказались различными, составляя соответственно 8,26 Дж/г сухого веса и 66,6°С; 10,10 Дж/г сухого веса и 67,1°С соответственно. Представлен клинический пример нарушения метаболизма соединительной ткани век и склеры: пациент К., 72 года, с диагнозом ПОУГ II а правого глаза, ПОУГ III а левого глаза, начальная катаракта обоих глаз. ΔHд и Тд кожи века правого глаза (9,97 Дж/г и 66,3°С) оказались ниже, чем левого (13,1 Дж/г и 66,4°С). ΔHд и Тд склеры левого глаза составили 4,8 Дж/г и 65,9°С. После антиглаукоматозной операции левого глаза зафиксировано избыточное рубцевание вновь созданных путей оттока. ЗАКЛЮЧЕНИЕ. Выявлена отчетливая тенденция к увеличению поперечной связанности коллагена и его содержания в тканях век (кожи и хряща) с возрастом, при этом у пациентов с ПОУГ эти показатели оказались выше, чем у лиц той же возрастной группы без глаукомы

Laser-induced modification of the patellar ligament tissue: comparative study of structural and optical changes

The effects of non-ablative infrared (IR) laser treatment of collagenous tissue have been commonly interpreted in terms of collagen denaturation spread over the laser-heated tissue area. In this work, the existing model is refined to account for the recently reported laser-treated tissue heterogeneity and complex collagen degradation pattern using comprehensive optical imaging and calorimetry toolkits. Patella ligament (PL) provided a simple model of type I collagen tissue containing its full structural content from triple-helix molecules to gross architecture. PL ex vivo was subjected to IR laser treatments (laser spot, 1.6 mm) of equal dose, where the tissue temperature reached the collagen denaturation temperature of 60 ± 2°C at the laser spot epicenterin the first regime, and was limited to 67 ± 2°C in the second regime. The collagen network was analyzed versus distance from the epicenter. Experimental characterization of the collagenous tissue at all structural levels included cross-polarization optical coherence tomography, nonlinear optical microscopy, light microscopy/histology, and differential scanning calorimetry. Regressive rearrangement of the PL collagen network was found to spread well outside the laser spot epicenter (>2 mm) and was accompanied by multilevel hierarchical reorganization of collagen. Four zones of distinct optical and morphological properties were identified, all elliptical in shape, and elongated in the direction perpendicular to the PL long axis. Although the collagen transformation into a random-coil molecular structure was occasionally observed, it was mechanical integrity of the supramolecular structures that was primarily compromised. We found that the structural rearrangement of the collagen network related primarily to the heat-induced thermo-mechanical effects rather than molecular unfolding. The current body of evidence supports the notion that the supramolecular collagen structure suffered degradation of various degrees, which gave rise to the observed zonal character of the laser-treated lesion

Инвазивный аспергиллез, обусловленный Aspergillus non-fumigatus, у взрослых пациентов после аллогенной трансплантации гемопоэтических стволовых клеток

   Objective. To study the features of invasive aspergillosis (IA) due to A. non-fumigatus versus A. fumigatus in adult (≥ 18 years) recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 2016-2021.   Materials and methods. The study included 33 patients with IA caused by A. non-fumigatus (n = 20) and A. fumigatus (n = 13). A comparative analysis of cases of IA, the results of therapy and outcomes in patients after allo-HSCT in the RM Gorbacheva Research Institute was performed. Diagnostic criteria EORTC / MSGERC 2020 were used.   Results. Invasive aspergillosis caused by A. non-fumigatus made up the majority (60.6 %) of IA cases with an identified pathogen registered in patients after allo-HSCT in the period from 2016 to 2021. The main etiological agents in the A. non-fumigatus group were A. niger in 13 (65 %) patients, A. flavus – in 4 (20 %). The median day of diagnosis of A. non-fumigatus IAwas + 110 days (17–2093), for A. fumigatus it was + 46 days (2–866) (p = 0.171). Overall 12-week survival was 55 % and 59.2 % in the A. non-fumigatus and A. fumigatus groups, respectively (p = 0.617). The majority of patients in both the A. fumigatus (n = 10, 77 %) and A. non-fumigatus (n = 16, 80 %) groups received voriconazole as initial antifungal therapy. Second-linetherapy was required in 2 (10 %) patients with A. non-fumigatus IA: liposomal amphotericin B and echinocandins with or with-out posaconazole, and 2 (15 %) patients in the A. fumigatus group: liposomal amphotericin B and voriconazole in combination with echinocandins. A comparative analysis showed that in patients from the two groups, none of the assessed signs (gender, age, underlying disease, disease status at the time of transplantation, time from diagnosis to allo-HSCT, source of hematopoietic stem cells, conditioning regimen, donor type, antifungal prophylaxis, cytomegalovirus reactivation, severe acute and chronic graft-versus-host disease) did not differ significantly.   Conclusions. A. niger is the main causative agent of IA caused by A. non-fumigatus. Patients characteristics, their treatment and outcomes did not differ significantly between the A. non-fumigatus and A. fumigatus groups.   Цель: изучить особенности инвазивного аспергиллеза, обусловленного A. не-fumigatus в сравнении с A. fumigatus, у взрослых (≥ 18 лет) реципиентов аллогенной трансплантации гемопоэтических стволовыхклеток в 2016–2021 гг.   Материалы и методы. В исследование включили 33 пациента с инвазивным аспергиллезом, обусловленным A. не-fumigatus (n=20) и A. fumigatus (n=13), после аллогенной трасплантации гемопоэтических клеток, выполненной в клинике Научно-исследовательского института детской онкологии, гематологии и трансплантологии им. Р. М. Горбачевой. Использовали диагностические критерии EORTC / MSGERC, 2020.   Результаты. Обусловленный A. не-fumigatus инвазивный аспергиллез составил большую часть (60,6 %) случаев инвазивного аспергиллеза с идентифицированным возбудителем у пациентов после алло-трансплантации гемопоэтических стволовых клеток в 2016–2021 гг. В группе A. не-fumigatus основными возбудителями были A. niger (13, 65 %) и A. flavus (4, 20 %). Сравнительный анализ показал, что в группах сравнения ни один из оцениваемых признаков (пол, возраст, диагноз, статус заболевания на момент трансплантации, время от постановки диагноза до аллотрансплантации гемопоэтических стволовых клеток, источник гемопоэтических стволовых клеток, режим кондиционирования, тип донора, противогрибковая профилактика, реактивация цитомегаловируса, тяжелая острая и хроническая реакция трансплантат против хозяина) достоверно не различались. Медиана срока постановки диагноза A. не-fumigatus инвазивного аспергиллеза составила 110 дней (17 – 2093) после алло-трансплантации гемопоэтических стволовых клеток, A. fumigatus инвазивного аспергиллеза – 46 дней (2 – 866) (p = 0,171). Большинство пациентов с A. fumigatus инвазивным аспергиллезом (n = 10, 77 %) и A. не-fumigatus инвазивным аспергиллезом (n = 16, 80 %) в качестве стартовой противогрибковой терапии получали вориконазол. Терапия второй линии потребовалась 2 (10 %) пациентам с A. не-fumigatus инвазивным аспергиллезом (липосомальный амфотерицин В, эхинокандины и позаконазол) и 2 (15 %) пациентам с А. fumigatus инвазивным аспергиллезом (липосомальный амфотерицин В, вориконазол в комбинации с эхинокандином). Общая выживаемость пациентов с A. неfumigatus инвазивным аспергиллезом в течение 12 недель составила 55 %, A. fumigatus инвазивным асппергиллезом – 59,2 % (p = 0,617).   Выводы. A. niger – основной возбудитель инвазивного аспергиллеза, обусловленного A. non-fumigatus. Характеристики пациентов, их лечение и исходы достоверно не различались между группами A. не-fumigatus и A. fumigatus

РАСПРОСТРАНЕННОСТЬ ВИРУСА ГЕПАТИТА С СРЕДИ УСЛОВНО ЗДОРОВОГО НАСЕЛЕНИЯ РОССИЙСКОЙ ФЕДЕРАЦИИ

Aim. To determine the prevalence of hepatitis C virus (HCV) in different age groups of the conditionally healthy population of Russia.Materials and methods. Total 4764 serum samples from a conditionally healthy population of five regions of Russia (Moscow, Rostov, Sverdlovsk regions, Tyva Republic, and Sakha Republic (Yakutia) were tested. The study included persons of 10 age groups: < 1 year, 1–4 years, 5–9 years, 10–14 years, 15–19 years, 20–29 years, 30–39 years, 40–49 years, 50–59 years old, ≥ 60 years. Anti-HCV was determined in ELISA with commercial test systems. Anti-HCV positive samples were tested for HCV RNA by RT-PCR. The genotype of HCV was determined based on the analysis of the nucleotide sequences of the core and NS5B regions of the viral genome.Results. The overall prevalence of anti-HCV in 5 regions of Russia was 2,6% (126/4764), and the proportion of people with HCV RNA was 1,1% (50/4764). The highest anti-HCV positivity rate was observed in Tyva and Yakutia (3,3% in both regions), in other regions its prevalence varied from 1,7% (Moscow region) to 3,0% (Sverdlovsk region). The highest frequency of HCV RNA detection was observerd in Tyva Republic and Rostov region (1.3% in both regions). No positive for HCV RNA cases was detected among persons aged 0–19 years in any region, except for Tyva Republic (1,0% (1/98) in age group 15–19 years). Peak positivity rates of HCV RNA were detected in the age groups 20–29 years and 30–39 years in the Rostov Region (3,9% and 3,0%, respectively); in Yakutia – in the group of 30–39 years (3,7%), in Tyva – in the group of 40–49 years (3,6%), in the Moscow region – in the groups of 20–29 and 30–39 years (2,9% and 2,5%, respectively).Conclusion. The results obtained indicate a high degree of HCV infection in virtually all age groups in the interval from 20 years to ≥60 years. Specific age cohorts that might benefit from inclusion in regional HCV screening programs were identified in each region. Цель. Определить долю инфицированных вирусом гепатита С (ВГС) лиц в различных возрастных группах условно здорового населения России.Материалы и методы. Исследованы 4764 образца сы- воротки крови от условно здорового населения пяти регионов РФ: Свердловской, Ростовской, Московской областей, Республики Тыва и Республики Саха (Якутия). В исследование были включены лица 10 возрастных групп: меньше 1 года, 1–4 года, 5–9 лет, 10–14 лет, 15–19 лет, 20–29 лет, 30–39 лет, 40–49 лет, 50–59 лет, старше 60 лет. Анти-ВГС определяли в ИФА с коммерческими тест-системами. В положительных по анти-ВГС образцах определяли РНК ВГС методом ОТ-ПЦР. Генотип ВГС определяли на основании анализа нуклеотидных последовательностей участков core и NS5B вирусного генома.Результаты. Общая распространенность анти-ВГС в 5 регионах РФ составила 2,6% (126/4764), доля лиц с РНК ВГС – 1,1% (50/4764). Наибольшая распространенность анти-ВГС выявлена в Республиках Тыва и Якутия (3,3%), в остальных регионах данный показатель варьировал от 1,7% (Московская область) до 3,0% (Свердловская область). Наибольшая частота выявления РНК ВГС отмечена в Республике Тыва и Ростовской области (1,3% в обоих регионах). Среди лиц в возрасте от 0 до 19 лет РНК ВГС не была выявлена ни в одном регионе, за исключением Республики Тыва (1% (1/98) в группе 15–19 лет). Пиковые показатели выявления РНК ВГС были вы- явлены в возрастных группах 20–29 лет и 30–39 лет в Ростовской области (3,9% и 3,0% соответственно); в Якутии – в группе 30–39 лет (3,7%), в Тыве – в группе 40–49 лет (3,6%), в Московской области – в группах 20–29 лет и 30–39 лет (2,9% и 2,5% соответственно).Заключение. Полученные результаты свидетельствуют о высокой степени пораженности ВГС практически всех возрастных групп в интервале от 20 лет до ≥ 60 лет. В каждом из обследованных регионов выявлены возрастные когорты, для которых целесообразно включение в региональные скрининговые программы.

A Comparative Study of Age-Related Level of Sclera Collagen Crosslinking in Patients with Different Stages of Primary Open Angle Glaucoma

Age-related levels of sclera collagen crosslinking have been studied in 75 patients aged 50-91 (averagely 69.9 ± 9.2 years) with various degrees of primary open angle glaucoma (POAG), whose sclera samples were obtained during deep nonpenetrating sclerectomy. The patients were divided into three age groups: 50-59 years (21 patients), 60-69 years (22 patients), and over 70 years (32 patients). 19 eyes of these patients had POAG stage I, 24 eyes had POAG stage II, and 32 eyes had stage III. To assess the level of collagen cross-linkage, sclera thermograms obtained by differential scanning calorimetry (Phoenix®, DSC 204, Netzsch, Germany) involving collagen denaturation temperature (Tm) and enthalpy value (∆Hm) measurements were analyzed. The level of collagen cross-linkage of glaucomatous sclera was found to increase with age and the stage of glaucomatous damage. However, the formation of excessive cross links associated with glaucomatous damage seems to play a more important role in damaging its structural and biomechanical properties than crosslinking of collagen complexes caused by natural aging, since the differences in values of thermomechanical parameters Tm and ∆Hm across different age groups (staying, respectively, within 0.8-1.0 оС and 0.3-2.1 J/g of dry residue) proved to be less substantial than the differences associated with the progression of glaucoma (varying, respectively, within 1.9-2.6 оС and 6.7-13.2 J/g of dry residue). The identified structural and biomechanical changes of the corneoscleral eye shell in patients with POAG do not fit into the pattern of natural aging processes; they are most probably based on the metabolic disorder of the connective tissue // Russian Ophthalmological Journal, 2016; 1: 19-26