Mathematical simulation application for research of nonuniform distributed-parameter circuit transients

This paper considers the simulation capability of nonuniform distributed-parameter circuit transients by using MatLab Simulink. This approach is capable of determining currents and voltages of nodes for power networks of any configurations and modes. The paper contains results of nonuniform line simulations in idle, short-circuit and load modes

The new technologies of high-throughput single-cell RNA sequencing

A wealth of genome and transcriptome data obtained using new generation sequencing (NGS) technologies for whole organisms could not answer many questions in oncology, immunology, physiology, neurobiology, zoology and other fields of science and medicine. Since the cell is the basis for the living of all unicellular and multicellular organisms, it is necessary to study the biological processes at its level. This understanding gave impetus to the development of a new direction – the creation of technologies that allow working with individual cells (single-cell technology). The rapid development of not only instruments, but also various advanced protocols for working with single cells is due to the relevance of these studies in many fields of science and medicine. Studying the features of various stages of ontogenesis, identifying patterns of cell differentiation and subsequent tissue development, conducting genomic and transcriptome analyses in various areas of medicine (especially in demand in immunology and oncology), identifying cell types and states, patterns of biochemical and physiological processes using single cell technologies, allows the comprehensive research to be conducted at a new level. The first RNA-sequencing technologies of individual cell transcriptomes (scRNA-seq) captured no more than one hundred cells at a time, which was insufficient due to the detection of high cell heterogeneity, existence of the minor cell types (which were not detected by morphology) and complex regulatory pathways. The unique techniques for isolating, capturing and sequencing transcripts of tens of thousands of cells at a time are evolving now. However, new technologies have certain differences both at the sample preparation stage and during the bioinformatics analysis. In the paper we consider the most effective methods of multiple parallel scRNA-seq using the example of 10XGenomics, as well as the specifics of such an experiment, further bioinformatics analysis of the data, future outlook and applications of new high-performance technologies

Вплив легувальної добавки на теплофізичні та реологічні властивості полімерної композиції, що не містить галогенів, для ізоляції та оболонок кабелів

Introduction. The demand for halogen-free fire-resistant compositions for the manufacture of fire-retardant wires and cables is constantly growing. Problem. Therefore, the creation and further processing of these materials is an urgent problem. Goal. The aim of the article is to study the effect of the doping additive on the thermophysical and rheological properties of halogen-free compositions for power cables with voltage 1 kV with the determination of both the temperatures of phase and structural transformations of polymer compositions. Methodology. Experiments investigating the phase transformations were carried out with the help device of thermogravimetric analysis and differential scanning calorimetry TGA/DSC 1/1100 SF of METTLER TOLEDO company. Rheological studies of polymeric materials were conducted by using the method of capillary viscosimetry in the device IIRT–AM. Results. The influence of the doping additive on the formation of the supramolecular structure of the filled polymer compositions for cable products was determined, that resulted in the temperature increase of the decomposition beginning by 11 °С and the end of decomposition by 7 °С. Originality. The effect of a doping additive on reducing the effective melt viscosity of a polymer composition from 6·104 to 1·104 Pa·s with increasing shear rate has been shown for the first time. The shear rate of the polymer composition containing the doping additive increases from 0.5 to 20 s–1 with increasing shear stress. Practical value. The research results provide an opportunity to reasonably approach the development of effective technological processes for the manufacture of the insulation and sheaths of power cables from halogen-free polymer compositions.Попит на вогнестійкі композиції, що не містять галогенів, для виготовлення пожежобезпечних проводів та кабелів безперервно зростає. Тому розробка цих матеріалів є актуальною проблемою. Метою статті є дослідження впливу легувальної добавки на теплофізичні та реологічні властивості композицій. Теплофізичні властивості визначено з використанням приладу TGA/DSC 1/1100 SF компанії METTLER TOLEDO. Реологічні дослідження полімерних матеріалів проведено методом капілярної віскозиметрії на приладі ИИРТ-АМ. Визначено вплив легувальної добавки на формування надмолекулярної структури наповнених полімерних композицій. Встановлено зниження ефективної в’язкості розплаву полімерної композиції в 6 разів зі зростанням швидкості зсуву в 40 разів при зміненні температури від 150 до 190 °С. Швидкість зсуву полімерної композиції з легувальною добавкою зростає в 40 разів з підвищенням напруження зсуву в 9 разів. Результати досліджень дають можливість обґрунтовано підходити до розроблення ефективних технологічних процесів виготовлення ізоляції та оболонок силових кабелів

An effective serum- and xeno-free chemically defined freezing procedure for human embryonic and induced pluripotent stem cells

Both human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) bear a great potential in regenerative medicine. In addition to optimized clinical grade culture conditions, efficient clinical grade cryopreservation methods for these cells are needed. Obtaining good survival after thawing has been problematic

Особенности детской глаукомы: обзор литературы

Despite the rare incidence of childhood glaucoma in the routine practice of an ophthalmologist, the status of a disabling disease dictates the need to treat this group of patients as carefully and warily as possible. Difficulties with the diagnosis, the choice of the optimal treatment algorithm and the subsequent tactics of monitoring patients with pediatric glaucoma necessitated detailed coverage of this pathology with the accumulation and systematization of data from various sources. The review combines the concepts of etiology, pathogenesis, classification, and also focuses on diagnostic criteria and therapeutic approaches in the management of patients with pediatric glaucoma. The current data on the genetics of the disease are detailed, the underlying mechanisms for the development of glaucoma in children are highlighted, and various classification systems are also reviewed. International criteria for diagnosis are also included. Attention is drawn to the importance of choosing a pathogenetically substantiated surgical technique. The importance of timely verification of the diagnosis and promptly initiated treatment is emphasized. Despite the aggressiveness and refractory nature of the disease, it is possible, with promptly and adequately taken measures, to maintain sufficiently high visual functions for the patient to continue an independent lifestyle.Несмотря на редкую частоту встречаемости детской глаукомы в рутинной практике врача-офтальмолога, статус инвалидизирующего заболевания диктует необходимость максимально внимательно и настороженно относиться к данной группе пациентов. Трудности постановки диагноза, выбора оптимального алгоритма лечения и последующей тактики наблюдения пациентов с детской глаукомой обусловили необходимость подробного освещения данной патологии с аккумуляцией и систематизацией данных различных источников. В обзоре объединены концепции этиологии, патогенеза, классификации, а также акцентировано внимание на диагностических критериях и терапевтических подходах при ведении пациентов с детской глаукомой. Детализированы современные данные по генетике заболевания, освещены основополагающие механизмы развития глаукомы у детей, а также рассмотрены различные классификационные системы. Приведены международные критерии для постановки диагноза. Отмечена важность выбора патогенетически обоснованной хирургической методики. Особо подчеркнута значимость своевременной верификации диагноза и, соответственно, незамедлительно начатого лечения, так как, несмотря на агрессивность и рефрактерность заболевания, при срочно и адекватно принятых мерах возможно сохранение достаточно высоких зрительных функций для ведения пациентом в дальнейшем независимого образа жизни

Controlled Transformation of Electrical, Magnetic and Optical Material Properties by Ion Beams

Key circumstance of radical progress for technology of XXI century is the development of a technique which provides controllable producing three-dimensional patterns incorporating regions of nanometer sizes and required physical and chemical properties. Our paper for the first time proposes the method of purposeful direct transformation of the most important substance physical properties, such as electrical, magnetic, optical and others by controllable modification of solid state atomic constitution. The basis of the new technology is discovered by us effect of selective atom removing out of thin di- and polyatomic films by beams of accelerated particles. Potentials of that technique have been investigated and confirmed by our numerous experiments. It has been shown, particularly, that selective atom removing allows to transform in a controllable way insulators into metals, non-magnetics into magnetics, to change radically optical features and some other properties of materials. The opportunity to remove selectively atoms of a certain sort out of solid state compounds is, as such, of great interest in creating technology associated primarily with needs of nanoelectronics as well as many other "nano-problems" of XXI century.Comment: 22 pages, PDF, 9 figure

Investigation of Two-Phase Flow in AxialCentrifugal Impeller by Hydrodynamic Modeling Methods

The article provides a methodology to study the flow in the wet part of the pump with fundamentally new axial-centrifugal impeller by methods of hydrodynamic modeling in the software package STAR CCM +. The objective of the study was to determine the normal and cavitation characteristics of the pump with a new type of wet part, as well as optimization of the geometrical parameters of the pump. Authors solved this problem using an example of the hot coolant pump, which should meet high requirements for cavitation quality and efficiency (hydraulic efficiency up to 87%, critical value of NPSH to 2.2 m).Also, the article focuses on the methods of numerical solution of two-phase flow simulation in a pump that are needed for a more accurate simulation of cavitation in the pump and research work in liquids with high gas content.Hydrodynamic modeling was performed on a computing cluster at the department E-10 of BMSTU for pump flow simulation in unsteady statement of problem using the computational grid size to 1.5 million cells. Simultaneously, the experimental model of the pump was made by 3D printing and tested at the stand in the BMSTU. Test results, which were compared with the calculated data are also given in the article. Inaccuracy of the calculation of pump head does not exceed 5%.The simulation results may be of interest to specialists in the field of hydrodynamic modeling, and for designers of such pumps. The authors also report production of a full-length prototype of the pump in order to conduct further testing for the verification of the data in the article, primarily in terms of cavitation characteristics.</p

МЕТОД КОНТРОЛЮ ЦІЛІСНОСТІ ПЕРЕДАНИХ БЛОКІВ ІНФОРМАЦІЇ

Context. For the proper operation of the hardware and software systems, it is necessary that the hardware component receives data only from the corresponding software. Otherwise, the data received from extraneous programs that can be perceived and processed by the device, which can lead to errors in the operation of the device or even a complete loss of its functionality or data. Objective. In order to increase the reliability of legal software data and identify the challenges of the transfer of blocks, this article focuses on a comprehensive study of the problems arising from the transmission of information in the form of separate data blocks. Method. The methods of integrity control in modes of transmission are described. The method based on hashes and block delivery time is analyzed in detail, analysis the methods of reducing the probability of errors occurring in the receiver and the possibility of reducing the reception of the extraneous blocks when receiving individual blocks of information. This is done by using a set of mathematical equations. And measure the extent of the effect of intensity of receiving extraneous blocks and hash field length.Results. In the process of analyzing systems in which information is transmitted by block, when using the method of formation of information chains based on the method the hashes and the delivery time of the block, where we note, when the value of the hash field is equal to 6 or more, the probability of occurrence of duplicate branches is acceptably low. Where, when hash field more then 6, the parameter of length of a chain practically does not affect the final probability of constructing a chain from the extraneous blocks. The very same value of the probability of constructing a false chain, the length exceeding the chain of legal blocks at hash field more 6 is about1 10–3, which it’s acceptable for real information transmission systems.Conclusions. Based on the analysis, we can conclude that in systems in which information is transmitted block by block, when using the method of generating information chains based on the hash and block arrival time, with a hash field of 6 or more, the probability of occurrence of duplicate branches is acceptably low. Актуальность. В статье уделяется внимание всестороннему изучению проблем, возникающих при передаче информации в виде отдельных блоков данных (кадров, фреймов).Метод. Описаны методы контроля целостности в таких способах передачи. Детально рассмотрен метод на основе хешей и времени доставки блока, проанализированы методы снижения вероятности ошибок, возникающих в приёмнике при приёме отдельных блоков информации.Результаты. В процессе анализа систем, в которых информация передается по блокам, при использовании метода формирования информационных цепочек на основе метода хэшей и время доставки блока, где мы отмечаем, когда значение хеш-поля равно до 6 или более, вероятность появления дублирующих ветвей является приемлемо низкой. Когда хеш-поле больше 6, параметр длины цепочки практически не влияет на конечную вероятность построения цепочки из посторонних блоков. Само же значение вероятности построения ложной цепочки, длина которой превышает цепочку допустимых блоков в хэш-поле больше 6, составляет примерно 10–3, что приемлемо для реальных систем передачи информации.Выводы. На основе проведенного анализа можно сделать вывод, что в системах, в которых информация передаётся поблоково, при использовании метода формирования информационных цепочек на основе хеша и времени поступления блока, при величине поля хеша от 6 и более вероятность возникновения дублирующих ветвей приемлемо низка. Актуальність. У статті приділено увагу всебічному вивченню проблем, що викликають передачу інформації у вигляді окремих блоків даних (кадрів, фреймів).Метод. Описані методи контролю цілості у таких способах передачі. Детально розглянуто метод на основі ґешів і часу доставки блоку, проаналізованих методами зниження ймовірності помилок, відновлюючих прийомів при приєднанні окремих блоків інформації.Результати. У процесі аналізу систем, в яких інформація передається блоком, при використанні методу формування інформаційних ланцюгів на основі методу хешів і часу доставки блоку, де ми зазначаємо, коли значення ґеш-поля дорівнює  6 і більше, ймовірність появи повторюваних гілок є прийнятно низькою. Де, коли ґеш-поле більше 6, параметр довжини ланцюга практично не впливає на остаточну ймовірність побудови ланцюга із сторонніх блоків. Саме це значення ймовірності побудови помилкового ланцюга, довжина якого перевищує ланцюжок легальних блоків у ґеш-полі більше 6 становить приблизно 10–3, що є прийнятним для реальних систем передачі інформації.Висновки. На основі проведеного аналізу можна зробити висновок, що в системах, в яких інформація передається поблоково, при використанні методу формування інформаційних ланцюжків на основі ґешу і часу надходження блоку, при величині поля ґешу від 6 і більше ймовірність виникнення дублюючих гілок є прийнятно низьклю.

Development of a Technology for Interactive Design of Garments Using Add-ons of a Virtual Mannequin

The problem of development of the technology of interactive garment designing by engineering methods was studied, which makes it possible to use the passive mode for automated preparation of design documentation. The theoretical background for modular approaches to formalization of the structural design of clothing is the stated principles of coordination of the actions in the algorithms of transformation of the sets of a research object. The technology of construction of a geometric model of an object is represented by three kinds of information models: digital, meshed, and surface. The analytical and experimental research resulted in substantiation of the algorithm of project situations of the transformation of the surface of the original object in the form of an electronic mannequin, into the garment design.The original database for construction and modification of the frame 3D mannequin models was theoretically substantiated with a view to ensuring the reliability of their visualization.We studied the mechanism of interactive modification of surface shells of clothing in the cycle of its silhouette deformation and of the construction of flat sweeps of clothes, adapted to the vectors of modifying the mannequin surface sections in order to receive the garment designs identical to the original of the morphological structure of the consumer's body.4 scenarios of design situations of the regarmention and transformation of the 3D-model of the silhouette surface of a mannequin and of the garment by the optimal route were proposed to improve the speed and the quality of processes of computer-aided design of clothing parts for the figures of typical and atypical physique.The image construction apparatus of the digital model of a three-dimensional object takes into consideration the topology of the geometrical structure of a shape and the morphological field of synergies of the elements in the processes of transition from 3D to 2D designing.The scenario of the adaptation of silhouette 3D images of a garment to the modified 2D design documents grounded on database verification was proposed. Assessment of the effectiveness of the garment design technology was made by the number of iterations of project operations in design procedures with the quality level chec

POLYMORPHISM OF EYE DRAINAGE SYSTEM CHANGES IN GLAUCOMA

The study aim was to investigate structural peculiarities of sclera in different types of glaucoma, with an accent on changes of the eye drainage system. Materials and methods. Comparative descriptive case-control study of 103 patients (206 eyes) with different glaucoma types has been carried out: primary congenital glaucoma - 8 people, juvenile open-angle glaucoma - 10, primary open-angle glaucoma - 24, pseudoexfoliative - 35, pigmentary - 4, angle-closure -22. A pathomorphological study of 103 surgical scleral specimens has been conducted. Results. Distinctive changes of eye drainage system connective tissue were revealed according to the glaucoma type. Congenital glaucoma is characterized by an abundance of collector channels, a quantity of matrix-producing cells and explicit hydrophilic fiber compartment of sclera. Angle-closure glaucoma is defined by aseptic inflammation with polymorphic perivascular cell infiltrate and edema of eye drainage system endothelium as well. Structural equivalents of a long-lasting dystrophic process with a gradual destruction and reduction of cell elements are distinguishing features of primary open-angle glaucoma. Different glaucoma types vary in the explicitly and location of pigment imbibition of the drainage system components. Conclusion. Stereotypical and specific changes of eye drainage system were revealed in pathomorphogenesis of different types of glaucoma. These features determine the universal character and polymorphism of clinical aspects of glaucoma