The influence of hydrogen on the mechanical and functional properties of TiNi and TiNiFe single crystals

The effect of hydrogen on temperature dependence of critical stress σcr(T), the shape memory effect and superelasticity for [11]-oriented single crystals of Ti-50.7Ni (at.%) and [23]-oriented single crystals of Ti-49%Ni-1%Fe (at.%) alloys at tensile deformation has been studied. It was shown that the change of temperatures of the martensitic transformation, symmetry of thermal hysteresis and level of σcr(Ms) and σcr(B2) stresses are determined by the phase state of the material (martensite or austenite) in the process of hydrogenation

The effect of hydrogen on shape memory effect and superelasticity in single-phase nickel titanium single crystals

The effect of hydrogen on temperature dependences of axial stresses σcr(T), shape memory effect, and superelasticity of [1¯11]-oriented Ti-50.7% Ni (at %) alloy single crystals has been studied under tensile strain in a single-phase state. It is established that the level of σcr(Ms) and σcr(B2) stresses is determined by the state of hydrogen (in solid solution or titanium hydride particles) in the initial B2 phase. Superelasticity up to 2.0–2.5% occurs when hydrogen is present in the solid solution

Influence of hydrogen on mechanical properties of [012]-crystals of austenitic steel Fe-18Cr-14Ni-2Mo

The influence of hydrogen alloying on critical shear stress, strain hardening coefficient and crystal plasticity depending on temperature of testing in the range of 77...400 К and hydrogen atom concentration has been investigated on monocrystals of austenitic stainless steel Fe-18Cr-14Ni-2Mo with low staking fault energy. Hydrogenation up to 14 at. % is shown to result in 1,5...2 increase of strength properties expressed by temperature dependence of critical shearing strains and to encourage development of local deformation by sliding

Shape memory effect and superelasticity in [001] single crystals of FeNiCoAlNb(B) alloys

In given paper presents data research of influence of boron on the functional properties - the shape memory effect and superelasticity in the [001] single crystals FeNiCoAlNb(B) alloys aged at 973 K for 5 hours. On the [001] single crystals FeNiCoAlNbB at aging at T = 973 K for 5 hour, it is shown, that boron leads to decrease the start Ms temperature of γ-α' martensitic transformation on cooling, to the development of γ-α' stress induced martensitic transformation at higher stress at one test temperature and to increase of thermal ΔT and stress Δσ hysteresis is compared to [001] crystals without boron

Circulating free DNA in hypertensive patients with high cardiovascular risk

Aim. To evaluate the level of circulating free nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) in hypertensive patients with high cardiovascular risk.Material and methods. The study included 70 patients, of which 51 were patients with hypertension (HTN) and 19 were healthy. The study of the level of circulating free nDNA and mtDNA was carried out using quantitative polymerase chain reaction (PCR). Additionally, demographic data, comorbidities, risk factors, heredity, results of complete blood count and biochemical blood tests, electrocardiography and echocardiography were analyzed.Results. The level of nDNA in HN patients was significantly higher than in healthy patients: Me (LQ; UQ) — 227 (110; 370) copies/mL and 88 (62; 116) copies/ml, respectively (p<0,0001). In hypertensive patients with a very high cardiovascular risk, the level of nDNA and mtDNA was significantly higher compared to healthy participants: 294 (154; 489) copies/ml versus 88 (62; 116) copies/ml, p<0,0001; 56731 (42531; 129375) copies/mL versus 35156 (18325; 54956) copies/mL, p=0,015.Conclusion. The level of circulating free DNA in hypertensive patients with very high cardiovascular risk is significantly increased, and therefore this parameter can be a cardiovascular risk marker

EFFECT OF AGING ON FUNCTIONAL AND MECHANICAL PROPERTIES OF SINGLE CRYSTALS CONIGA ALLOY

На [001]-монокристаллах Co49Ni21Ga30 (ат, %) установлено, что выделение частиц γ'-фазы размером 3–5 нм после старения 623 К в течение 15 минут приводит к снижению температуры начала прямого мартенситного превращения на 150 К, уменьшению величины обратимой деформации в 2 раза, увеличению величин термического и механического гистерезисов в 1.5–3 раза и расширению температурного интервала проявления сверхэластичности на 80 К.On [001]-oriented Co49Ni21Ga30 (at,%) single crystals it was established that presipitation of γ'-phase particles in size of 3–5 nm after aging of 623 K for 15 minutes leads to a decrease in the start martensitic transformation temperature by 150 K, a decrease in the reversible strain in 2 times, an increase in the values of thermal and stress hysteresis in 1.5–3 times, and an expansion of the temperature range of the superelasticity on 80 K.Работа выполнена при финансовой поддержке гранта РФФИ № 16-38-00608

Эволюция методики и новые протоколы ультразвукового исследования легких при COVID-19 пневмониях

Competent triage of patients with COVID-19 pneumonia is not only about efficient allocation of hospital resources, but also about making timely decisions that can ultimately save the patient's life. When healthcare facility is overloaded, computed tomography to assess the severity of COVID-19-associated pneumonia in each individual case is not always possible. Alternative solutions, however, are opted.The aim of the study was to develop Lung UltraSound (LUS) protocols with high diagnostic potential for assessing the severity of pneumonia caused by COVID-19, which can be reliably used instead of CT during triage in an emergency setting.Materials and methods. We conducted a retrospective analysis of data on 161 hospitalized patients with confirmed pneumonia caused by COVID-19, subjected to both CT and LUS within 24 hours after hospitalization. Three consecutive LUS protocols, including two LUS developed by the NMHC (National Medical Surgical Center) authors, were tested to choose the most reliable protocol for assessing the severity of lung damage in pneumonia caused by COVID-19 (based on correlation with chest CT results). We also checked the applicability of LUS for the prognosis of the disease.Results. Moderate (50% CT) and severe (50% CT) lung damage can be distinguished when using both - the 16-zone and 12-zone LUS NMHC scanning protocols. The AUC for the ROC curves was almost identical: 0.83 (95% CI: 0.75–0.90 and 0.81 (95% CI: 0.73–0.88) for the 16-zone and 12-zone LUS NMHC protocols, respectively. The 16-zone LUS NMHC had an optimal threshold of 20 scores with a sensitivity of 67% and a specificity of 82%, while the 12-zone LUS NMHC provided an optimal threshold of 15 scores with the same sensitivity but lower specificity — only 73%. Neither the 16-zone nor the 12-zone NMHC LUS protocols could predict the outcome.Conclusion. The newly developed 16- and 12-zone LUS NMHC scanning protocols for patients with pneumonia caused by COVID-19 proved to be easy to implement, demonstrating a strong correlation with CT results. The 16-zone LUS NMHC protocol is probably more relevant for triage of patients with more than 50% of pulmonary tissue involvement based on CT data. Both protocols can be useful in emergency settings and in medical institutions with limited or no access to CT.Сортировка пациентов с COVID-19 пневмонией — очень зависимая от времени задача, которая позволяет эффективно распределить ресурсы больницы, что в конечном итоге может привести к спасению жизни пациента.Проблемы использования компьютерной томографии в перегруженной системе здравоохранения требуют поиска дополнительных методов дифференцировки тяжести пневмонии, вызванной COVID-19.Цель исследования — разработка протоколов ультразвукового исследования легких (Lung Ultra-Sound — LUS) с высокими диагностическими характеристиками для определения тяжести пневмонии, вызванной COVID-19, которые можно использовать вместо КТ во время сортировки в условиях неотложной помощи.Материалы и методы. Провели ретроспективный анализ данных о 161 госпитализированном пациенте с подтвержденной пневмонией, вызванной COVID-19, которым в течение 24 ч после госпитализации выполнили как КТ, так и LUS. Три последовательных протокола LUS, в том числе два, разработанные авторами LUS NMHC (National Medical-Surgical Center), тестировали, чтобы выбрать из них наиболее надежный для определения выраженности повреждения легких при пневмонии, вызванной COVID-19 (исходя из корреляции с результатами КТ грудной клетки). Проверили также применимость LUS для построения прогноза заболевания.Результаты. С помощью как 16-зонного, так и 12-зонного LUS NMHC протокола можно различать умеренное (50% по КТ) и тяжелое (50% по КТ) повреждение легких. AUC для кривых ROC была почти идентична: 0,83 (95% СИ, 0,75–0,90) и 0,81 (95% СИ 0,73–0,88) для 16-зонного и 12-зонного LUS NMHC протоколов, соответственно. 16-зонный LUS NMHC имел оптимальный порог 20 баллов с чувствительностью 67% и специфичностью 82%, в то время как 12-зонный LUS NMHC обеспечивал оптимальный порог 15 баллов с той же чувствительностью, но более низкой специфичностью — только 73%. Ни по 16-зонному, ни по 12-зонному LUS-протоколам NMHC нельзя было прогнозировать исход.Заключение. Недавно разработанные 16- и 12-зонные протоколы LUS NMHC для пациентов с пневмонией, вызванной COVID-19, оказались просто выполнимыми и имели сильную корреляцию с результатами КТ. 16-зонный протокол LUS NMHC вероятно более применим для сортировки пациентов, у которых по КТ имеется более 50% объема повреждения легких. Оба протокола могут быть полезны в условиях неотложной помощи и в медицинских учреждениях с ограниченным или отсутствующим доступом к КТ

Два подхода к расчёту расчленения гидрографа стока реки с ледниковым питанием с помощью изотопных методов

Application of the stable isotope method in the balance equations used to calculate separation of the runoff hydrograph from the Djankuat Glacier basin is demonstrated. Simultaneous solution of equations of water, isotope and ion balances is applied to estimate contributions of different components and processes to formation of the Djankuat River runoff regime. For June 2014, we made calculations for the purpose to separate contributions of the spring (isotopically weighted) snow and winter (isotopically depleted) snow. Field works in the glacial basin Djankuat were performed during two ablation seasons, i.e. from June to September of 2013 and 2014. Two approaches were used when calculating separation of the runoff hydrograph by means of solution of systems of equations for isotopic and ion balances: 1) taking account of the isotope fractionation during snow melting, and 2) with no account for the fractionation. Separation of the hydrograph for June 2014 have shown that about 15–20% of the Djankuat River runoff is formed by spring snow melting, sometimes increasing up to 36%. Contribution of spring meltwater to the total runoff increases when the isotope fractionation during the snow melting is taken into account for the calculations. In this case, the contribution of spring snow changes from 30 to 50%.Рассмотрено применение метода стабильных изотопов в балансовых расчётах расчленения гидрографа стока с ледника Джанкуат. Изученные изотопные вариации стока на замыкающем створе р. Джанкуат для двух сезонов абляции 2013 и 2014 г. совместно с измерениями δ18О и минерализации различных источников питания р. Джанкуат (атмосферные осадки, снег разных сезонов, фирн, лёд и грунтовые воды) позволили расчленить гидрограф стока 2014 г. Применялись два методических подхода к расчётам: разделение гидрографа стока решением систем уравнений ионного и изотопного баланса с учётом изотопного фракционирования при таянии снега и без учёта фракционирования. Установлена величина погрешности расчётов с использованием значений δ18О и абсолютных концентраций 18О

ИНТРАПЕРИТОНЕАЛЬНОЕ ХИМИОПЕРФУЗИОННОЕ ЛЕЧЕНИЕ ДИССЕМИНИРОВАННОГО РАКА ЯИЧНИКА ДИОКСАДЭТОМ В СРАВНЕНИИ С ЦИСПЛАТИНОМ В ЭКСПЕРИМЕНТЕ

Comparative study of antitumor activity of cisplatin and dioxadet in chemoperfusion treatment was carried out on ascitic ovarian cancer model in 172 Vistar female rats. Ovarian cancer was inoculated intraperitoneally at a volume of 0.5 ml per rat with concentration of tumor cells 2×107 / ml. The drugs were administered once in 48 hours after inoculation of ovarian cancer in maximum tolerated doses (MTD). Normothermic intraperitoneal chemoperfusion (IPEC) and hyperthermic intraperitoneal chemoperfusion (HIPEC) were performed with cisplatin or dioxadet at doses that were 5−20 times higher than those for their standard intraperitoneal administration. Antitumor effects of the drugs were estimated in increase of median survival time (MST). In case of IPEC and HIPEC cisplatin increased the MST by 317  % and 183  % (р<0.05) respectively, when dioxadet increased the MST by 244  % and 444  % (р<0.05) respectively compared to the control group of animals that didn’t receive any treatment. HIPEC with dioxadet is the most effective regimen in experimental treatment of advanced ovarian cancer