Heat tolerance of titanium boride and titanium nitride contacts to gallium arsenide

For contacts prepared from titanium borides by and nitrides ion-plasma sputtering onto gallium arsenide both formation mechanisms and thermal stability were investigated. We used a combination of structural, secondary-emission, optical and electrophysical methods, such as electronography, X-ray diffraction, atomic force microscopy, Auger electron spectroscopy, secondary-ion mass spectrometry, taking photoluminescence spectra and I - V curves. A physical model for contact formation was proposed. According to it, BxGa₁₋xAs (GaNxAs₁₋x) solid solutions are formed at the phase interfaces when titanium borides (nitrides) are deposited. The defects are produced in the semiconductor near-surface regions during heterostructure formation and further heat treatment. The correlation between the physico-chemical interactions at contact interfaces and the contact electrophysical parameters occurs through these defects. The objects of our investigation demonstrated high thermal stability. This was due to their two-layer structure formed by components having well-pronounced antidiffusion properties. As a result, the interdiffusion processes at the phase interfaces are drastically weakened

Porous nanostructured InP: technology, properties, application

We prepared porous InP (100) substrates with a nanostructured surface relief on which InP epitaxial films were grown. The structure, morphological, and photoluminescence properties of nanostructured substrates and InP epilayers grown on them were studied. These InP epilayers grown on the porous and standard InP substrates were used to make microwave diodes. We showed the advantages of the diodes made on the porous substrates (over those made on the standard ones) caused by higher structural perfection of the InP epilayers grown on the porous substrates

ОПРЕДЕЛЕНИЕ СРОКОВ НАЧАЛА ГЕМОДИАЛИЗА: РАЗРАБОТКА И ПОДТВЕРЖДЕНИЕ ШКАЛЫ START

Aim. The optimal time for initiating of chronic dialysis remains unknown. The scale for mortality risk assessment could help in decision-making concerning dialysis start timing.Methods. We randomly divided 1856 patients started dialysis in 2009–2016 into developmental and validation group (1:1) to create and validate scoring system «START» predicting mortality risk at dialysis initiation in order to fi nd unmodifi able and modifi able factors which could help in the decision-making of dialysis start. In the series of univariate regression models in the developmental set, we evaluated the mortality risk linked with available parameters: age, eGFR, serum phosphate, total calcium, hemoglobin, Charlson comorbidity index, diabetes status, urgency of start (turned to be signifi cant) and gender, serum sodium, potassium, blood pressure (without impact on survival). Similar hazard ratios were converted to score points.Results. The START score was highly predictive of death: C-statistic was 0.82 (95% CI 0.79–0.85) for the developmental dataset and 0.79 (95% CI 0.74–0.84) for validation dataset (both p < 0.001). On applying the cutoff between 7–8 points in the developmental dataset, the risk score was highly sensitive 81.1% and specifi c 67.9%; for validation dataset, the sensitivity was 78.9%, specifi city 67.9%. We confi rmed the similarity in survival prediction in the validation set to developmental set in low, medium and high START score groups. The difference in survival between three levels of START-score in validation set remained similar to that of developmental set: Wilcoxon = 8.78 (p = 0.02) vs 15.31 (p < 0.001) comparing low–medium levels and 25.18 (p < 0.001) vs 39.21 (p < 0.001) comparing medium–high levels.Conclusion. Developed START score system including modifi able factors showed good mortality prediction and could be used in dialysis start decision-making. Цель. Оптимальное время начала лечения гемодиализом (ГД) остается неопределенным. Создание шкалы для оценки рисков для пациента, начинающего диализ, поможет в принятии решения о сроках его начала.Методы. По данным регистра пациентов на заместительной почечной терапии проанализированы результаты лечения 1856 пациентов, начавших диализ в 2009–2016 гг. Случайным образом их разделили в соотношении 1:1 на группу разработки и группу подтверждения для создания прогностической шкалы оценки вероятности летального исхода при лечении программным гемодиализом (шкала START). При этом учитывали модифицируемые и немодифицируемые факторы риска. В серии регрессионных моделей с одной переменной в группе разработки шкалы мы оценивали риски смерти, связанные с доступными для анализа модифицируемыми и немодифицируемыми параметрами. Среди них значимыми оказались возраст, расчетная скорость клубочковой фильтрации (рСКФ), уровни фосфатов, общего кальция, гемоглобина, индекс коморбидности Чарлсон, наличие сахарного диабета, экстренность старта диализа. Пол, уровни натрия, калия, артериального давления не оказали влияния на выживаемость. Близкие по величине риски были преобразованы в баллы шкалы.Результаты. Шкала START продемонстрировала высокую предсказательную ценность в отношении риска смерти: AUC 0,82 (95% ДИ 0,79–0,85) для группы разработки шкалы и 0,79 (95% ДИ 0,74–0,84) для группы подтверждения (для обеих p < 0,001). Для точки отсечения 7–8 баллов чувствительность метода составила 81,1%, специфичность 69,9% для группы разработки и 78,9 и 67,9% соответственно – для группы подтверждения. Мы подтвердили близкие значения выживаемости пациентов в обеих группах для низких, средних и высоких значений шкалы START. Различия в выживаемости для подгрупп с тремя уровнями шкалы были близкими для групп разработки и подтверждения: критерий Wilcoxon = 8,78 (p = 0,02) vs 15,31 (p < 0,001) при сравнении выживаемости подгрупп низких и средних величин шкалы и 25,18 (p < 0,001) vs 39,21 (p < 0,001) при сравнении выживаемости подгрупп средних и высоких величин шкалы.Заключение. Разработанная шкала START, включающая модифицируемые факторы риска, продемонстрировала хорошую предсказательную ценность в отношении 5-летней летальности и может использоваться при принятии решения о времени старта диализа.

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Influence of plastic deformation at high hydrostatic pressure on properties of metal matrix composites

Translated from Russian (Proceedings of Advanced Materials '99: Institute of Materials Science Problems, Nat. Acad. of Sciences of Ukraine 1999)Available from British Library Document Supply Centre-DSC:9023.190(10038)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Structural and phase transformations in single-crystal alloy ZhS36-VI [001] after holding in the range of 1050 - 1300°C

The special features of structure and phase transformations in alloy ZhS36-VI [001] after long high-temperature holds are considered. Formation of μ-phases with different morphology and of a (γ +γ′) structure of the nanosize level is discovered. The temperature-time domain of existence of the phases in alloy ZhS36-VI [001] is plotted. © 2012 Springer Science+Business Media, Inc

Automated checking of detail drawing with the use of open educational resources

The creation of the course «Engineering graphics» at the National open education platform has led to the need to solve the problem of automation of the verification of the drawing. The detail drawing can be performed in a variety of ways – sketches, manually or using various graphics programs. The implementation of drawing – a creative process in which the will of the author can change the main image, quantity, choices, cuts, sections. Dimensioning and specifying values of the roughness of surfaces is also diverse. The teacher is able to assess the correctness of any of the embodiment of the drawing, but how to implement an automated test? – The task of checking a graphic of the proposed transfer by the students. «Easy» solution involves considerable painstaking study of all elements of the task graphic disciplines that will ensure the maximum correctness of the drawing.Создание курса «Инженерная графика» на Национальной платформе открытого образования привело к необходимости решения задачи автоматизации проверки выполнения чертежа. Чертеж детали может быть выполнен различными способами – эскизно, вручную или с помощью различных графических программ. Выполнение чертежа – творческий процесс, в котором по воле автора могут меняться главное изображение, их количество, варианты выбора разрезов, сечений. Простановка размеров и задание значений шероховатости поверхностей также многообразны. Преподаватель способен оценить правильность любого варианта исполнения чертежа, но как осуществить автоматизированную проверку? – Задачу проверки графической работы предлагаем передать самим обучающимся. «Легкость» решения проблемы предполагает значительную кропотливую проработку всех элементов задания графической дисциплины, которая максимально обеспечит правильность выполнения чертежа