Physical Parameters of Polymer Composite Materials Created on the Basis of Low and High Molecular Weight Rubbers

ABSTRACT. The theoretical foundations of the structural and mechanical behavior of filled three-dimensional cross-linked elastomers are supplemented. Numerical experiments are carried out, based on the data of numerical experiments, three dimensional cross linked, filled with dispersed particles frost-resistant elastomers based on low and high molecular weight rubbers are developed. Theoretical and experimental data are compared and their good convergence is shown. Comparison of the physical parameters of the composites created by the authors on the basis of low and high molecular weight rubbers showed that the deformation characteristics of the composite based on high molecular weight rubbers are many times superior to composites based on low molecular weight, as well as their glass transition temperature is also very different. The created composites are recommended as a structural material in relation to the engineering problem of creating wear-resistant parts and components of road and air transport operated in a wide temperature range, including the Far North and the Arctic. &nbsp

Sasanian Pseudo-Signet-Ring Excavated at the Palace of Mangup: The Aspects of Its Attribution and Interpretation

Поступила в редакцию 04.08.2021. Принята к печати 15.10.2021.Submitted: 04.08.2021. Accepted: 15.10.2021.В 2006 г. в ходе раскопок дворца правителей княжества Феодоро (1425–1475) в центральной части Мангупского городища (Юго-Западный Крым), был обнаружен уникальный для памятника перстень из желтоватого халцедона, изготовленный в VI – начале VII в. на территории Сасанидского Ирана. Находка относится к числу так называемых ложных перстней-печаток (мухр), имеет эллипсоидную форму (сплющенная полусфера) с узким каналом для подвешивания на шее, запястье или поясе. На щитке перстня представлено изображение горного барана (архар) с круто загнутыми рогами, лежащего влево с поджатыми ногами. Его сопровождает ряд официальных символов правящей династии в государстве Сасанидов: царский бант ашхараванд (обвязанная лента на одной из передних ног животного), полумесяц рогами вверх (молодая Луна, один из символов династии) и аташдан (зороастрийский храмовый алтарь с пылающим огнем). Композиция изображения восходит к легенде об основателе династии Сасанидов царе Ардашире I (224–240), которому одержать победу над последним парфянским правителем Артабаном V (213–224) и взойти на престол помогло божество царской власти, победы, могущества, удачи и славы Фарр, воплощенное в образе горного барана. Таким образом, первый владелец находки входил в состав по крайней мере привилегированной части сасанидского общества, а перстень использовался им в роли подписи или знака собственности при опечатывании личных документов и предметов торговых операций. Рассматривая обстоятельства обнаружения сасанидского перстня в культурном слое одной из крупнейших византийских крепостей в Таврике, построенной, очевидно, в конце правления императора Юстиниана I (527–565), вряд ли стоит серьезно рассматривать версии прямой официальной переписки между местной византийской администрацией и кем-то из иранских корреспондентов или присутствия здесь воинских контингентов из Персии. Скорее всего, находка является обычным трофеем византийского офицера, принимавшего участие в одной из многочисленных византийско-сасанидских военных кампаний второй половины VI – первой трети VII в. и затем продолжившего службу в составе гарнизона Мангупа-Дороса.In 2006, the excavation of the palace of the rulers of the Principality of Theodoro (1425–1475) in the central area of the ancient town of Mangup (south-western Crimea) uncovered a unique at this site signet-ring of yellowish chalcedony made in the sixth or early seventh century in Sasanian Iran. This find belongs to a group of the so-called pseudo-signet-rings (muhr); it shows an ellipsoidal shape (flattened hemisphere) with a narrow channel for hanging on the neck, wrist, or belt. On the shield of the signet-ring there is an image of a mountain sheep (аrhar) with steeply curved horns, lying to the left, with the legs tucked. It was accompanied with a number of official symbols of the ruling dynasty in the Sassanian State: the royal bow ashkharavand (of a ribbon tied round a front leg of the animal), a crescent with the horns upward (a young Moon, one of the symbols of the dynasty), and atashdan (Zoroastrian temple altar with burning fire). The composition of this image goes back to the legend about the founder of the Sassanian dynasty King Ardashir I (224–240), who defeated the last Parthian ruler Artaban V (213–224) and ascended the throne with the help from the deity of royal power, victory, might, luck, and glory Farr embodied in the mountain ram. Therefore, the first owner of the signet-ring was a member of the privileged part of the Sassanian society, using the ring to make signature or as a sign of ownership when sealing personal documents and items of trade transactions. Considering the circumstances of the discovery of the Sassanian ring in the cultural layer of one of the largest Byzantine fortresses in Taurica obviously constructed at the end of the reign of Emperor Justinian I (527–565), it is hardly worth thinking of direct official correspondence between the local Byzantine administration and someone from Iranian correspondents or the presence of the military contingents from Persia. Most likely, the find in question was simply a trophy of a Byzantine officer who took part in one of the many Byzantine Sassanian military campaigns of the second half of the sixth or the first third of the seventh centuries and then continued his service in the garrison of Mangup-Doros.This study was funded by the Russian Foundation for Basic Research, project no. 19-09-00124 The Palace Complex of the Mangup Settlement – the Residence of the Rulers of the Principality of Theodoro in the South-West Crimea. Problems of Chronology, Planning and Architectural Reconstruction of the Monument.Исследование выполнено при финансовой поддержке Российского фонда фундаментальных исследований, проект №19-09-00124 «Дворцовый комплекс Мангупского городища – резиденция правителей княжества Феодоро в Юго-Западном Крыму. Проблемы хронологии, планировки и архитектурной реконструкции памятника»

The PI Launchpad: Expanding the base of potential Principal Investigators across space sciences

The PI Launchpad attempts to provide an entry level explanation of the process of space mission development for new Principal Investigators (PIs). In particular, PI launchpad has a focus on building teams, making partnerships, and science concept maturity for a space mission concept, not necessarily technical or engineering practices. Here we briefly summarize the goals of the PI Launchpad workshops and present some results from the workshops held in 2019 and 2021. The workshop attempts to describe the current process of space mission development (i.e. space-based telescopes and instrument platforms, planetary missions of all types, etc.), covering a wide range of topics that a new PI may need to successfully develop a team and write a proposal. It is not designed to replace real experience but to provide an easily accessible resource for potential PIs who seek to learn more about what it takes to submit a space mission proposal, and what the first steps to take can be. The PI Launchpad was created in response to the high barrier to entry for early career or any scientist who is unfamiliar with mission design. These barriers have been outlined in several recent papers and reports, and are called out in recent space science Decadal reports.Comment: 7 Pages, 2 Figure, Accepted to Frontier

Evaluation of the Implementation of FDG-PET/CT and Staging Laparoscopy for Gastric Cancer in The Netherlands

Background: The role of 18F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) and staging laparoscopy (SL) has increased in the preoperative staging of gastric cancer. Dutch national guidelines have recommended the use of FDG-PET/CT and SL for patients with locally advanced tumors since July 2016. Objective: The aim of this study was to evaluate the implementation of FDG-PET/CT and SL in The Netherlands. Methods: Between 2011 and 2018, all patients who underwent surgery for gastric cancer were included from the Dutch Upper GI Cancer Audit. The use of FDG-PET/CT and SL was evaluated before and after revision of the Dutch guidelines. Outcomes included the number of non-curative procedures (e.g. palliative and futile procedures) and the association of FDG-PET/CT and SL, with waiting times from diagnosis to the start of treatment. Results: A total of 3310 patients were analyzed. After July 2016, the use of FDG-PET/CT (23% vs. 61%; p < 0.001) and SL (21% vs. 58%; p < 0.001) increased. FDG-PET/CT was associated with additional waiting time to neoadjuvant therapy (4 days), as well as primary surgical treatment (20 days), and SL was associated with 8 additional days of waiting time to neoadjuvant therapy. Performing SL or both modalities consecutively in patients in whom it was indicated was not associated with the number of non-curative procedures. Conclusion

Familial co-occurrence of congenital heart defects follows distinct patterns

Aims Congenital heart defects (CHD) affect almost 1% of all live born children and the number of adults with CHD is increasing. In families where CHD has occurred previously, estimates of recurrence risk, and the type of recurring malformation are important for counselling and clinical decision-making, but the recurrence patterns in families are poorly understood. We aimed to determine recurrence patterns, by investigating the co-occurrences of CHD in 1163 families with known malformations, comprising 3080 individuals with clinically confirmed diagnosis. Methods and results We calculated rates of concordance and discordance for 41 specific types of malformations, observing a high variability in the rates of concordance and discordance. By calculating odds ratios for each of 1640 pairs of discordant lesions observed between affected family members, we were able to identify 178 pairs of malformations that co-occurred significantly more or less often than expected in families. The data show that distinct groups of cardiac malformations co-occur in families, suggesting influence from underlying developmental mechanisms. Analysis of human and mouse susceptibility genes showed that they were shared in 19% and 20% of pairs of co-occurring discordant malformations, respectively, but none of malformations that rarely co-occur, suggesting that a significant proportion of co-occurring lesions in families is caused by overlapping susceptibility genes. Conclusion Familial CHD follow specific patterns of recurrence, suggesting a strong influence from genetically regulated developmental mechanisms. Co-occurrence of malformations in families is caused by shared susceptibility genes

Fostering Continuous Innovation with Engaging IT-Assisted Transparent Information Sharing : A Case Study

The paper received the Honorary Mention – Best Paper Award Nominee.Peer reviewe

Assessment of actual nutrition among children with multiple milk teeth caries attending preschool educational institutions

The purpose of the study is to assess the actual nutrition of preschool children with multiple caries of milk teeth.Цель исследования – оценить фактическое питание детей и обеспеченность витамином D у детей дошкольного возраста с множественным кариесом молочных зубов

Prognostic value of [18F]FDG PET radiomics to detect peritoneal and distant metastases in locally advanced gastric cancer: a side study of the prospective multicentre PLASTIC study

Aim: To improve identification of peritoneal and distant metastases in locally advanced gastric cancer using [18F]FDG-PET radiomics. Methods: [18F]FDG-PET scans of 206 patients acquired in 16 different Dutch hospitals in the prospective multicentre PLASTIC-study were analysed. Tumours were delineated and 105 radiomic features were extracted. Three classification models were developed to identify peritoneal and distant metastases (incidence: 21%): a model with clinical variables, a model with radiomic features, and a clinicoradiomic model, combining clinical variables and radiomic features. A least absolute shrinkage and selection operator (LASSO) regression classifier was trained and evaluated in a 100-times repeated random split, stratified for the presence of peritoneal and distant metastases. To exclude features with high mutual correlations, redundancy filtering of the Pearson correlation matrix was performed (r = 0.9). Model performances were expressed by the area under the receiver operating characteristic curve (AUC). In addition, subgroup analyses based on Lauren classification were performed. Results: None of the models could identify metastases with low AUCs of 0.59, 0.51, and 0.56, for the clinical, radiomic, and clinicoradiomic model, respectively. Subgroup analysis of intestinal and mixed-type tumours resulted in low AUCs of 0.67 and 0.60 for the clinical and radiomic models, and a moderate AUC of 0.71 in the clinicoradiomic model. Subgroup analysis of diffuse-type tumours did not improve the classification performance. Conclusion: Overall, [18F]FDG-PET-based radiomics did not contribute to the preoperative identification of peritoneal and distant metastases in patients with locally advanced gastric carcinoma. In intestinal and mixed-type tumours, the classification performance of the clinical model slightly improved with the addition of radiomic features, but this slight improvement does not outweigh the laborious radiomic analysis. </p