Specific Absorption Rate of Fractal-like Aggregates of Magnetic Nanopaticles

A specific absorption rate of fractal-like assemblies of iron oxide nanoparticles in alternating magnetic field has been calculated using stochastic Landau-Lifshitz equation which simultaneously takes into account both the presence of thermal fluctuations of the nanoparticle magnetic moments, and strong magneto-dipole interaction between the nanoparticles of the clusters. No appreciable difference in the magnetic properties of various types of fractal clusters has been revealed. It is also found that the specific absorption rate of dilute assemblies of fractal clusters shows only weak dependence on the number of the nanoparticles within the clusters. Keywords: Magnetic nanoparticles, Fractal clusters, Magneto- dipole interaction, Low frequency hysteresis loop

Реокинетические исследования формирования сетчатых структур в полимерах

Methods of networks formation in different polymers or olygomers are considered. The possibility of rheokinetic description for chemical network formation in elastomers and their binary blends evaluation was shown. These elastomers differ from each other by polarity, reactivity and crosslinking mechanisms. Rheokinetic method represents the new approach for vulcanization regimes, structure and properties of such materials optimizationРассмотрены методы изучения про- цесса образования сетчатых струк- тур в различных полимерах и олиго- мерах. Показана возможность применения реокинетического подхода для оценки процесса формирования химической сетки в бинарных смесях полимеров, различаю- щихся полярностью, реакционной способ- ностью и механизмом сшивания. Реоки- нетический метод представляет собой новый подход к составлению режимов вулканизации эластомеров и оптимиза- ции структуры и свойств материалов на их основе

Неонатальный скрининг на тяжелую комбинированную иммунную недостаточность в России: прекрасное дале ко или завтрашняя реальность?

Mass screening of newborns in Russia for five hereditary diseases does not meet the requirements of the world community for the neonatal screening program. Success in the development of laboratory diagnostic technologies and active introduction of achievements in genetics and molecular biology into medical practice allow for the revision of the list of nosologies included in the national neonatal screening program by replacing the disease or adding new nosologies. The article discusses the possibility of including genetic testing for severe combined immune deficiency in the Newborn Screening Program in Russia. The results from a retrospective study of markers of naive T- and B-lymphocytes (TREC and KREC) in the group of children with immuno-dependent pathology developed in the first year of life are discussed. © 2017 Voprosy Sovremennoi Pediatrii - Current Pediatrics. All rights reserved

Segmentation of muscle tissue in computed tomography images at the level of the L3 vertebra

With the increasing routine workload on radiologists associated with the need to analyze large numbers of images, there is a need to automate part of the analysis process. Sarcopenia is a condition in which there is a loss of muscle mass. To diagnose sarcopenia, computed tomography is most often used, from the images of which the volume of muscle tissue can be assessed. The first stage of the analysis is its contouring, which is performed manually, takes a long time and is not always performed with sufficient quality affecting the accuracy of estimates and, as a result, the patient’s treatment plan. The subject of the study is the use of computer vision approaches for accurate segmentation of muscle tissue from computed tomography images for the purpose of sarcometry. The purpose of the study is to develop an approach to solving the problem of segmentation of collected and annotated images. An approach is presented that includes the stages of image pre-processing, segmentation using neural networks of the U-Net family, and post-processing. In total, 63 different configurations of the approach are considered, which differ in terms of data supplied to the input models and model architectures. The influence of the proposed method of post-processing the resulting binary masks on the segmentation accuracy is also evaluated. The approach, which includes pre-processing with table masking and anisotropic diffusion filtering, segmentation with an Inception U-Net architecture model, and post-processing based on contour analysis, achieves a Dice similarity coefficient of 0.9379 and Intersection over Union of 0.8824. Nine other configurations, the experimental results for which are reflected in the article, also demonstrated high values of these metrics (in the ranges of 0.9356–0.9374 and 0.8794–0.8822, respectively). The approach proposed in the article based on preprocessed three-channel images allows us to achieve metrics of 0.9364 and 0.8802, respectively, using the lightweight U-Net segmentation model. In accordance with the described approach, a software module was implemented in Python. The results of the study confirm the feasibility of using computer vision to assess muscle tissue parameters. The developed module can be used to reduce the routine workload on radiologists

Определение параметров лазерной обработки алмазов с применением метода конечных элементов и искусственных нейронных сетей

This paper provides the simulation of laser processing of diamonds by using a combination of artificial neural networks and the finite element method. The training data array and the data array for testing neural networks were generated in ANSYS. The calculations were performed for 600 types of input parameters, 60 of which were used to test artificial neural networks. The influence of the parameters of neural network models on the accuracy of determining temperatures in the laser processing area were studied. The parameters of neural networks were established that provide acceptable results in predicting temperatures generated by laser radiation in diamonds. The results obtained can be used to determine the technological parameters of the laser processing of diamonds.С помощью сочетания искусственных нейронных сетей и метода конечных элементов выполнено моделирование процесса лазерной обработки алмазов. Обучающий массив данных и массив данных для тестирования нейронных сетей были сформированы с использованием программы конечно-элементного анализа ANSYS. Расчеты выполняли для 600 вариантов входных параметров, 60 из которых использовали для тестирования искусственных нейронных сетей. Исследовано влияние параметров нейросетевых моделей на точность определения температур в зоне лазерной обработки. Установлены параметры нейронных сетей, обеспечивающие приемлемые результаты при прогнозировании температур, формируемых лазерным излучением в алмазах. Полученные результаты могут быть использованы при определении технологических параметров процессов лазерной обработки алмазов

Двулучевая лазерная очистка кварцевого сырья

The paper presents a numerical simulation of laser separation under the influence of laser beams with wavelengths  of  10.6  microns  and  1.06  microns  on  quartz  raw  material  used  in  the  electronics  industry in  the  manufacture  of  photomasks.  The  temperature  fields  obtained  by  the  finite  element  method  and the analytical solution are compared. The temperature distribution to a depth of 50 microns is almost the same when using both methods of solution, while with increasing depth the temperature difference increases by 10 %, which allows using both methods of solution, since in practice the temperature distribution in the near-surface layers,  which  determines  the  formation  of  agglomerates  with  impurity  inclusions,  is  more  important. It  is  revealed  that  the  efficiency  of  separation  of  quartz  raw material  depends  on  the  processing  speed  and the energy properties of laser radiation, which allows to choose the optimal processing parameters that ensure the effective formation of agglomerates containing impurity inclusions. Experimental studies of bi-beam laser cleaning  of  quartz  raw  material  were  carried  out,  which  allowedus to determine the optimal processing parameters of quartz raw material for effective cleaning of it from impurity inclusions, that make it possible to manufacture photomasks used in the production of microcircuits with improved performance characteristics.В  работе  выполнено  численное  моделирование  лазерной  сепарации  при  воздействии лазерных  пучков  с  длинами  волн,  равными  10,6  и  1,06  мкм,  на  кварцевое  сырье,  используемое в электронной промышленности при изготовлении фотошаблонов. Выполнено сравнение температурных полей,  полученных  при  моделировании  методом  конечных  элементов и  с  помощью  аналитического решения.  Распределение  температуры  до  глубины  50  мкм  практически  совпадает  при  использовании обеих методик решения, при этом с увеличением глубины разница температур возрастает на 10 %, что позволяет  использовать  обе  методики  решения,  так  как  на  практике  более  важным  является распределение  температур  в  приповерхностных  слоях,  которое  определяет  формирование  агломератов с примесными  включениями.  Выявлено,  что  эффективность  сепарации кварцевого  сырья  зависит  от скорости  обработки  и  энергетических  свойств  лазерного  излучения,  что  позволяет  подобрать оптимальные  параметры  обработки, обеспечивающие  эффективное  образование  агломератов, содержащих примесные включения. Проведены экспериментальные исследования двулучевой лазерной очистки  кварцевого  сырья,  которые  позволили  определить  оптимальные  параметры  обработки кварцевого  сырья  для  эффективной  очистки  его  от  примесных  включений,  что  обеспечивает возможность  изготовления  фотошаблонов  с  улучшенными  эксплуатационными  характеристиками, применяемых при производстве микросхем

Анализ генеалогических данных у взрослых с первичными иммунодефицитами

This study was aimed at analysis of pedigrees of adult patients with primary immunodeficiency (PID). Methods. We examined 94 adults with primary immunodeficiency and 217 adults without this disease. Genealogy analysis was made at least for four generations in all patients. Results. Relatives of most PID patients (75 %) had autoimmune disorders. Relatives of near all (99 %) of PID patients had allergic diseases. Sixty nine per cent of PID patients had cases of infant death due to infectious or oncological diseases in ancestors. Conclusion. Genealogy analysis of patients with confirmed or suspected PID could be an important diagnostic measure. Data about relatives with atypical infectious, inflammatory or autoimmune diseases are the most valuable.В клинической практике недостаточно уделяется внимания составлению родословных пациентов, выявлению наследственной природы заболевания, характера наследования болезни. Это касается как редких, так и широко распространенных болезней. При этом генеалогический анализ при выявлении и подозрении на первичный иммунодефицит (ПИД) исключительно важен как в клиническом, так и в прогностическом плане. В сформированных группах проведено сравнение генеалогических данных у родственников пациентов с ПИД и без такового

Сравнение адсорбционных свойств оксида цинка и шунгита в связи с их действием в качестве активаторов серной вулканизации

Determination of the adsorption characteristics of zinc oxide and shungite with respect to benzene vapor adsorption was carried out by the BET method. The specific surface area was calculated, the curves of pore volumes distribution according to their size were constructed. The possibility of using shungite as an activator of sulfur vulcanization of butadiene-nitrile rubbers was shown.Проведено определение адсорбционных характеристик оксида цинка и шунгита по адсорбции паров бензола методом БЭТ. Рассчитаны удельные поверхности, построены кривые распределения объемов пор по их размерам. Показана возможность применения шунгита в качестве активатора серной вулканизации бутадиен-нитрильных каучуко

Determination of reference values for TREC and krec in dry blood spots of Newborns from different gestation ages in Sverdlovsk region

As a preparatory stage for implementation of genetic testing for severe combined immunodeficiency under a neonatal screening program, a study was performed in Sverdlovsk Region which concerned quantitative determination of T and B cell neogenesis markers (TREC and KREC, respectively) in blood of conditionally healthy newborns. Archived samples of dry blood spots collected in test-forms for routine neonatal screening were used as biological material for the study of full-term 26 girls and 26 boys who did not exhibit serious illnesses during first year of their life. In addition, we investigated potential effects of foetal gestational age upon the number of TREC and KREC in preterm infants. Blood samples from 55 preterm infants (23 to 36 gestational weeks) were also examined. It was shown that the levels of TREC and KREC increased sequentially with the increased gestation terms, but the quantitative changes of markers showed different dynamics. In this respect, the recommended terms of blood sample collection for SCID screening is entirely consistent with timing of blood sampling for routine newborn screening. An alternative result was obtained with a complete absence of TREC or KREC in blood sample of a newborn, irrespectively of prematurity degree (at valid copy numbers of a control gene) which should serve as an indication for immediate consulting of the child by immunologist and in-depth immunological examination, because it may be a first prognostic sign of a fatal disease. In order to obtain correct cut-off levels for TREC/KREC, additional studies are needed on a larger sample of newborns (1.000 to 5.000), followed by validation of the obtained reference boundaries in studies involving patients with different forms of primary immunodeficiencies. © 2018, SPb RAAC