bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of ultrasound in primary care: Longitudinal billing and cross-sectional survey study in Switzerland
Authors: Touhami Dima , Merlo Christoph , Hohmann Joachim , Essig Stefan
Published: March 2020

Background Ultrasound imaging is utilized in Swiss primary care; however, little is known regarding the extent to which it is performed. A course in Point-of-Care ultrasound (POCUS) has been recently introduced to promote and improve the utilization of ultrasound. POCUS will offer faster certification compared to previous courses thanks to a limited set of targeted examinations. With this study, we aim to (1) provide an overview of ultrasound use by general practitioners (GPs), and (2) determine how the clinical uses of ultrasound relate to the targeted objectives of POCUS. Methods This is a quantitative study, analyzing fifteen years of billing data from 213 GPs in Central Switzerland and cross-sectional survey data completed by 61 GPs attending 26 certification and refresher courses offered by the Swiss Society of Ultrasound in Medicine (SGUM). Results According to billing data, 49% of the GPs used ultrasound and provided 130,245 exams to 67,180 patients between 2004 and 2018. Over the years, ultrasound use became more frequent among GPs. Male GPs provide more ultrasound exams than female GPs. Patients that are female, ≥65 years, and multi-morbid had more ultrasound exams compared to males, patients <65 years, and those with only one morbidity, respectively. GPs provided a mean of 129 ultrasound exams per physician-year. Abdominal ultrasound comprised almost 69% of all exams. According to survey data, indications covered many organ systems and clinical conditions, with most POCUS indications being among them. Conclusions Utilization of ultrasound is high among general practitioners and covers a wide range of indications. A focus in certification on POCUS might reduce the variety of indications. Keywords: Ultrasound; general practice; primary care; general practitioners; clinical indications; POCUS; ultrasound certification; Switzerland
Cost of new born care interventions in four regions of Ghana: implications for health resource allocation.
Authors: Alhassan Robert Kaba
Published: March 2020

Background Limited financial, human and material health resources coupled with increasing demand for new born care services require efficiency in health systems to maximize the available sources for improved health outcomes. Making Every Baby Count Initiative (MEBCI) implemented by local and international partners in 2003 in Ghana aimed at attaining neonatal mortality of 21 per 1,000 livebirths by 2018 in four administrative regions in Ghana. Objective Determine the cost of MEBCI interventions towards sustaining new born care best practices, and strengthening capacity for frontline clinical staff involved in new born care. Methods Cost of MEBCI interventions was evaluated on unit cost calculations. Expenditure items trainings, supervisions, monitoring and evaluation, advocacy, administrative costs and logistics. Data collection started in October 2017 and ended in September 2018. Key cost data sources were invoices, expense reports and ledger books at the national, regional and district levels of MEBCI implementation. Results Approximately GH₵ 24.5 million (US$ 5.5 million) expenditure data was recorded as overall cost of MEBCI interventions at the national and regional levels of project activities. Out of this figure, fixed cost constituted 71% and recurrent cost represented 29%. A total of GH₵ 1.6 million (US$ 372,727) expenditure values were expended in strengthening national leadership at the national health level; nearly 70% of this cost was spent on workshops and training related activities. Cost of implementing MEBCI at the various regional health directorates was approximately GH₵ 17.6 million (US$ 3.9 million). Out of this amount, direct provider training and related activities constituted 98% and indirect cost accounted for the remaining 2%. Overall, it was found that the MEBCI interventions covered 4,027 health providers, out of which 3,453 (86%) were clinical healthcare staff. Conclusion The MEBCI intervention had a wide coverage in terms of training for frontline healthcare providers albeit the associated cost may be potentially unsustainable for the Ghana’s health system. M-learning and e-learning platforms could be leveraged to reduce cost of the on-site batch-training approach.
Description of Laimaphelenchus sinensis n. sp. (Nematoda: Aphelenchoididae) from declining Chinese pine, Pinus tabuliformis in Beijing, China
Authors: Gu Jianfeng , Maria Munawar , Fang Yiwu , Liu Lele , Bian Yong , Chen Xianfeng
Published: March 2020

Laimaphelenchus sinensis n. sp. isolated from declining Chinese pine, Pinus tabuliformis Carrière, is described and characterized morphologically and molecularly. The new species has four incisures in the lateral field and the excretory pore situated posterior to the nerve ring; the female has a vulval flap and vaginal sclerotization is quite prominent in majority of specimens. The female tail is conoid, ventrally curved having a single stalk-like terminus with 8 to 10 projections. The male spicules are 14.0 (13.2-15) μm long along curved median line and tail is ventrally curved typical of the genus; however, the projections are less prominent as compared to those of female. The male has two pairs of caudal papillae and Bursa is absent. Phylogenetically, the ribosomal DNA sequences of the new species placed it within Laimaphelenchus clade and are morphologically similar to L. persicus, L. preissii, L. simlaensis and L. unituberculus.
Assessment of financial monitoring efficiency in the banking system of Ukraine
Authors: Bukhtiarova Alina , Semenog Andrii , Razinkova Мila , Nebaba Nataliia , Antoni Haber Józef
Published: March 2020

The transformation processes taking place in the global economy and the expansion of global business ties increase the overall vulnerability of the international banking system. One of the problems related to money laundering is the process of evaluating the efficiency of financial monitoring measures. The article discusses the issues of assessing the effectiveness of financial monitoring in the banking system of the country. For Ukraine, this problem is especially relevant, because there is a bank-centric model of the financial market (about 90% of assets go through the banking system) in the country. According to official data, 50% of economic activity in Ukraine ends with money laundering. The article presents the improved method that quantifies the level of financial monitoring system effectiveness at commercial banks of Ukraine based on calculations of the integral index. The index indicates the dynamics of the financial system protection degree from the money laundering threat based on the expediency and efficiency of financial monitoring in the banking system. As a result, more comprehensive conclusions about the level of financial security of the country are made. According to assessments, in 2017–2018 the efficiency of financial monitoring of the banking system of Ukraine was at the middle level (about 64%). The proposed method can be applied to evaluate the effectiveness of the financial monitoring system in any country and become the basis for improving the anti-money laundering system through the banking system.
AcknowledgmentThe study was conducted as part of state budget research of Sumy State University – Formation of a Public Finance Transparency System as a Prerequisite for Combating Corruption in Ukraine (0118U003585) (in the context of evaluating the effectiveness of financial monitoring of the Ukrainian banking system) and Formation of Tools for the Ukrainian Economy Unshadowing Based on Causal Modeling of Interaction Trajectories of Financial Intermediaries (0120U100473) (in the context of substantiating the need and directions for improving the financial monitoring system in Ukrainian banks).
Las configuraciones locales de odio. Discursos antimigratorios y prácticas xenofóbicas en Foz de Iguazú, Brasil
Authors: Guizardi Menara Lube , Mardones Pablo
Published: March 2020

El objetivo del artículo es describir etnográficamente los impactos sociales de los discursos de odio antimigratorio en la ciudad brasileña de Foz de Iguazú (en la triple frontera del Paraná). Analizamos el actual contexto político brasileño indagando el impacto presente de los imaginarios del militarismo distendido en estas fronteras desde 1970. Utilizamos una metodología etnográfica, con la realización de 60 entrevistas cualitativas y un grupo focal con 11 participantes (estudiantes migrantes internacionales, profesores y personal técnico de la Universidad de la Integración Latinoamericana). Los resultados arrojan que la xenofobia fue convertida en discurso oficial en Brasil, articulándose a enunciados que preconizan la intolerancia hacia las minorías y sectores vulnerables. Esto incide de forma particular en Foz, dadas las configuraciones fronterizas y militares de la ciudad. Asimismo, el estudio permite concluir que tanto los discursos como prácticas xenofóbicas están articulados por imaginarios racistas que impactan más fuertemente a las mujeres migrantes.
COVID-19, SARS-CoV2, Enfeksiyonu: Güncel Epidemiyolojik Analiz ve Hastalık Seyrinin Modellemesi
Authors: ANKARALI Handan , ANKARALI Seyit , ERARSLAN Nadire
Published: March 2020

Dünya çapında 19 Mart 2020 itibariyle 170’in üzerinde ülkeyi saran COVID-19 enfeksiyonu neticesinde pozitif vakaların ve ölüm haberlerinin hızla yayıldığı herkes tarafından endişe ile takip edilmektedir. Sosyal medya ve internet ortamında çok ciddi düzeyde bilgi birikimi ortaya çıkmıştır. Bu çalışmanın amacı an itibariyle elde edilen veriler ışığında tüm dünya ülkelerinde enfeksiyon etkileri ve süreci hakkında genel yapıyı özetleyen istatistiki bilgiler sunmak ve enfeksiyon ölçütlerinin günlük değişimini modellemektir. Elde edilen sonuçlar değerlendirildiğinde, birikimli (kümülatif) pozitif vaka sayısı, birikimli ölüm sayısı ve diğer bazı ölçütlerin ülkelere göre seyrinin aynı olmadığı, süreci en iyi kontrol eden ülkelerin başında Almanya ve Güney Kore’nin geldiği, Türkiye’ nin sürecinin ilk 10 günlük süreç itibariyle hızlı yayılım gösteren ülkelere benzediği görüldü. Ayrıca Türkiye için 20 – 29 Mart 2020 arasında ortaya çıkabilecek pozitif vaka sayısı ve birikimli ölüm sayıları tahmin edildiğinde 20 Mart itibariyle pozitif vaka sayısının sayının 550 civarında, 4 olan mevcut ölüm sayısının hesaplamalarla birikimli ölüm sayısının ise 11 olacağı öngörülmüştür.
Vitamin K for the Treatment of Cardiovascular Disease in End-Stage Renal Disease Patients: Is there Hope?
Authors: Roumeliotis Stefanos , Roumeliotis Athanasios , Dounousi Evangelia , Eleftheriadis Theodoros , Liakopoulos Vassilios
Published: March 2020

In Chronic Kidney Disease, vascular calcification (VC) is highly prevalent even at early
stages and is gradually enhanced, along with disease progression to End-Stage Renal Disease (ESRD).
The calcification pattern in uremia includes all types of mineralization and contributes to the heavy
cardiovascular (CV) burden that is common in these patients. Ectopic mineralization is the result of the
imbalance between inhibitors and promoters of vascular calcification, with the latter overwhelming the
former. The most powerful, natural inhibitor of calcification is Matrix Gla Protein (MGP), a small vitamin
K dependent protein, secreted by chondrocytes and vascular smooth muscle cells. In uremia, MGP
was reported as the only molecule able to reverse VC by “sweeping” calcium and hydroxyapatite crystals
away from the arterial wall. To become biologically active, this protein needs to undergo carboxylation
and phosphorylation, reactions highly dependent on vitamin K status. The inactive form of MGP
reflects the deficiency of vitamin K and has been associated with CV events and mortality in ESRD
patients. During the past decade, vitamin K status has emerged as a novel risk factor for vascular calcification
and CV disease in various populations, including dialysis patients. This review presents evidence
regarding the association between vitamin K and CV disease in ESRD patients, which are prone
to atherosclerosis and atheromatosis.
Polyphenols can Potentially Prevent Atherosclerosis and Cardiovascular Disease by Modulating Macrophage Cholesterol Metabolism
Authors: Ito Fumiaki
Published: March 2020

Background:

Arterial atherosclerosis is the main pathological cause of coronary artery disease and peripheral arterial disease. Atherosclerosis is a chronic condition characterized by the presence of cholesterol-rich macrophages in the arterial intima. Accumulation of cholesterol in these macrophages is due to increased oxidation of low-density lipoprotein (LDL) and its uptake via scavenger receptors on the macrophages. Cholesterol efflux from the cholesterol-laden macrophages into high-density lipoprotein (HDL) is also a key process in maintaining cholesterol homeostasis and prevention of cholesterol accumulation. Four pathways for the efflux of cholesterol to HDL exist in macrophages, including passive and active pathways. Several HDL characteristics determine cholesterol efflux capacity, namely composition, oxidative status, and HDL size. Oxidation of LDL and HDL as well as any imbalance in cholesterol uptake and efflux could lead to accumulation of cholesterol in macrophages and initiation of atherosclerogenesis.

Conclusion:

Epidemiological studies have demonstrated that polyphenol-rich foods reduce cardiovascular events in the general population and in patients at risk of cardiovascular diseases. Many studies have reported that polyphenols in polyphenol-rich foods have anti-atherosclerotic properties by preventing cholesterol accumulation in macrophages through the suppression of lipoproteins oxidation and regulation of cholesterol uptake and efflux.
Imposing Packet Relaying for Mobile Adhoc Networks Using Genetic Algorithm
Authors: Theerthagiri Prasanna Venkatesan
Published: March 2020

Background:

Packet forwarding is an essential network operation in wireless networks
to establish communication among wireless devices. In mobile wireless networks, data transmission
occurs in the form of packet relaying. In dynamic environmental networks, relaying of the
packet is a more complex process and much essential activity.

Objective:

It requires the co-operation of intermediate nodes in the network. Specifically, in Mobile
Adhoc Networks (MANET) it is the most tedious job because of its dynamic topology, limited
energy, and other resource constraints. In this paper, a genetic algorithm is adopted for stimulating
the packet relaying, such that to assist the co-operation between various nodes in the network.

Methods:

The genetic algorithm is a metaheuristic process-based evolutionary algorithms. It intends
to produce high-quality optimized solutions to any given complex problems. The current research
work had carried out an extensive investigation and comparison of existing relevant genetic
algorithm based algorithms.

Results:

The experimental results are evaluated based on the methodology of the genetic algorithm,
the number of nodes, robustness, scalability, packet delivery ratio, average energy consumption,
and other parameters.
A Novel Wideband Transition from Substrate Integrated Waveguide to Rectangular Waveguide
Authors: Mahant Keyur , Mewada Hiren , Patel Amit , Vala Alpesh , Chaudhari Jitendra
Published: March 2020

Aim:

In this article, wideband Substrate Integrated Waveguide (SIW) and rectangular
waveguide (RWG) transition operating in Ka-band is proposed.

Objective:

To design wideband Substrate Integrated Waveguide (SIW) and rectangular waveguide
(RWG) transition operating in Ka-band.

Method:

The coupling patch was etched on the SIW cavity to couple the electromagnetic energy
from SIW to RWG. Moreover, metasurface was introduced into the radiating patch to enhance
bandwidth. To verify the functionality of the proposed structure back to back transition was designed
and fabricated on a single layer substrate using standard Printed Circuit Board (PCB) fabrication
technology.

Results:

Measured results match with the simulation results, measured insertion loss was less than
1.2 dB and return loss was better than 3 dB for the frequency range of 28.8 to 36.3 GHz. By fabricating
transition with 35 SRRs, bandwidth of the proposed transition can be improved.

Conclusion:

The proposed transition has advantages like compact size, easy to fabricate, low cost
and wide bandwidth. The proposed structure is a good candidate for millimeter-wave circuits and
systems.
Design, Synthesis, Anticancer Activity and Molecular Docking Studies of 2,5-Disubstituted-1,3,4-Oxadiazoles Containing Benzimidazole Moiety
Authors: Katikireddy Ramamurthy , Kakkerla Ramu , Krishna M.P.S. Murali , Durgaiah Gandamalla , Reddy Y.N.
Published: March 2020

A series of benzimidazolyl-1,3,4-oxadiazoles (7a-k) were synthesized and evaluated for in
vitro anticancer activity against HeLa, MCF7, A549, and HEK293 cell lines. The results indicate that
compounds 7b, 7j and 7k have shown excellent anticancer activity and while most of the compounds
were non toxic to normal HEK293 cell lines. Molecular docking results of the synthesized compounds
with the target Pin1 protein were also discussed.
The cognitive process and influence in learning
Authors: Parrales Enrique Byron Ayón , Palma Josefa Katiuska Toala , Álava Romina Adelina Quevedo , Campuzano Marcos Fernando Pazmiño
Published: March 2020

Learning is linked to the interactions of human brain functions. Every teacher or person who is linked to education is faced with the need and obligation to know how the human brain works and at the same time stimulate it with techniques and strategies that facilitate the assimilation of teaching. Cognitive processes play an important role in education, this help to interact preconceptions and knowledge with their natural and social environment, including processes in which it involves learning with which we acquire knowledge daily and routinely, whether it gives implicitly or explicitly, it helps to solve diverse situations, establishing logical and adequate connections with the help of reasoning because it conducts a behavioral and cognitive process of concentration that keeps us attentive.
Исследование примеси магния в кремнии
Authors: Порцель Л.М. , Шуман В.Б. , Лаврентьев А.А. , Лодыгин А.Н. , Абросимов Н.В. , Астров Ю.А.
Published: March 2020

Profiles of both electrically active and total concentration
of magnesium impurity in silicon were measured. Diffusion
was performed into the floating zone dislocation-free n-type
silicon at the temperatures Tdiff = 1000, 1100◦C and duration
from 0.5 to 22.5 h. The depth profiles of the electrically active
interstitial magnesium concentration NMgi (x) were determined by
differential conductivity method, while the total concentration
profile Ntotal(x) — with secondary ion mass spectroscopy. The
total concentration of magnesium was found to be almost two
orders higher than the concentration NMgi . It turned out that the
effective diffusion coefficient DMgi decreases with the diffusion
time. Possible physical processes responsible for formation of the
electrically inactive component of magnesium impurity and the
dependence of effective diffusion coefficient on time are discussed.
Оптические свойства гибридных гетероструктур GaN/SiC/por-Si/Si(111)
Authors: Середин П.В. , Голощапов Д.Л. , Золотухин Д.С. , Леньшин А.С. , Мизеров А.М. , Тимошнев С.Н. , Никитина Е.В. , Арсентьев И.Н. , Кукушкин С.А.
Published: March 2020

Abstract Using a complex of structural and spectroscopic methods of diagnostics, the influence of a nanoporous-silicon ( por -Si) transition layer on the optical properties of GaN layers grown on SiC/ por -Si/ c -Si templates by molecular-beam epitaxy with the plasma activation (MBE PA) of nitrogen is studied. It is shown for the first time that the MBE PA technology of the synthesis of GaN on a virtual SiC/ por -Si/ c -Si substrate provides a means for producing a GaN film of much higher structural and optical quality at a much lower growth temperature compared to those in similar studies, in which growth on porous Si substrates is demonstrated. The use of a por -Si layer makes it possible to improve the structural and morphological properties of the GaN epitaxial layer and to attain unique optical and electrical characteristics of the layer. The data obtained in the study will serve as an important basis for understanding the foundations of the physics of GaN/SiC/ por -Si nanoheterostructures and for promoting their potential use in optoelectronics.
О доминирующем механизме безызлучательного возбуждения ионов марганца в II-VI полумагнитных полупроводниках
Authors: Черненко А.В.
Published: March 2020

Doping of group II-VI semiconductors and low-dimensional structures based on them with manganese leads to effective quenching of electro-and photoluminescence provided that the electron excitation energy of the crystal exceeds the energy of the intracenter transition of Mn2+ EMn и 2.1 eV. Quenching involves efficient energy transfer from the photoexcited crystal to Mn2 + ions. There are three possible mechanisms of this non-radiative energy transfer: dipole-dipole, exchange and related mechanism associated with sp-d mixing. Although the dipole-dipole mechanism is thought to be ineffective due to the forbidden intracenter transition in Mn2+, and the spin-dependent exchange mechanism is dominant, not all experimental facts accumulated to date supports this conclusion. The article discusses two experimental approaches to identify the dominant mechanism of energy transfer to Mn2 + ions and to evaluate the partial contributions of the mechanisms. One of these approaches is related to optically detectable magnetic resonance at single diluted magnetic semiconductor quantum dots (QD), the second - to plasmon amplification of energy transfer to Mn2 + ions by means of dipole-dipole interaction.
Влияние легирования слоев брэгговских отражателей на электрические свойства InGaAs/GaAs метаморфных фотопреобразователей
Authors: Емельянов В.М. , Калюжный Н.А. , Минтаиров С.А. , Нахимович М.В. , Салий Р.А. , Шварц М.З.
Published: March 2020

Abstract The current–voltage characteristics of In_ x Ga_1 –_ x As/GaAs metamorphic photovoltaic converters with built-in n -InGaAs/InAlAs Bragg reflectors are studied at an indium content of x = 0 . 025–0 . 24. The series resistance of the heterostructures is measured in the temperature range from 90 to 400 K. It is found that a sharp rise in the resistance of silicon-doped reflectors with an increasing fraction of In is due to weak activation of the donor impurity in InAlAs– n :Si layers. As a result, the energy barriers for majority carriers are formed in the latter, with a height of 0 . 32–0 . 36 eV and a substantial width. To suppress this effect, the technology of the Te doping of n -InGaAs/InAlAs Bragg reflectors is developed, which reduces the series resistance by five orders of magnitude. This makes it possible to keep the fill factor of the current–voltage characteristic above 80% up to current densities of 2 A/cm^2. Values exceeding 85%, achieved for the quantum efficiency, indicate that the “memory” and tellurium segregation effects characteristic of this kind of impurity are suppressed.
Исследование напряжeнности внутренних электрических полей в активной области светодиодных структур на основе InGaN/GaN с разным числом квантовых ям методом спектроскопии электропропускания
Authors: Асланян А.Э. , Авакянц Л.П. , Червяков А.В. , Туркин А.Н. , Мирзаи С.С. , Курешов В.А. , Сабитов Д.Р. , Мармалюк А.А.
Published: March 2020

Abstract The internal electric fields of InGaN/GaN-based green-emission LED heterostructures with various numbers of quantum wells in the active region are investigated by electrotransmission spectroscopy. The frequencies of the observed spectral lines are attributed to possible types of interband transitions. An increase in the number of interband transitions of the “quantum well—quantum barrier” type with an increase in the number of quantum wells is found. This is explained by the nonidentical degree of segregation of In atoms in different GaN barriers layers. The strength of internal electric fields in quantum wells is calculated for various values of the bias of the p – n junction using a series of electrotransmission spectra. It is found that the strength of the internal piezoelectric field decreases from 3.20 to 2.82 MV/cm with an increase in the number of quantum wells.
Динамические смещения атомов и атермическое скольжение дислокаций в кристаллах
Authors: Хон Ю.А. , Zapolsky H.
Published: March 2020

A dislocation glide mechanism at low temperatures is proposed. The mechanism is based on taking into account the dynamic displacements of atoms — displacements caused by nonadiabatic transitions of atoms in a crystal with a dislocation under the action of an external force. Dynamic displacements initiate the instability of a direct dislocation of relatively low-amplitude displacements during atomic vibrations. The development of instability leads to the formation of a double kink and a dislocation shift by one interatomic distance.
Спектр излучения и стабильность двух типов электронно-дырочной жидкости в мелких Si/Si-=SUB=-1-x-=/SUB=-Ge-=SUB=-x-=/SUB=-Si квантовых ямах
Authors: Васильченко А.А. , Кривобок В.С. , Николаев С.Н. , Багаев В.С. , Онищенко Е.Е. , Копытов Г.Ф.
Published: March 2020

Abstract Based on calculations within the density functional theory and an analysis of low-temperature photoluminescence spectra, the structure of electron–hole liquid in shallow Si/Si_1 – _ x Ge_ x Si (100) quantum wells 5 nm wide with germanium content x = 3–5.5% is studied. It is shown that the energy of quasi-two-dimensional electron–hole liquid localized in quantum wells for this composition range as a function of carrier concentration exhibits two local minima. The position of the deeper (major) minimum depends on the quantum well design and controls properties of quasi-two-dimensional electron–hole liquid at low temperatures. For the series of Si/Si_1 – _ x Ge_ x Si quantum wells, modification of properties of electron–hole liquid was experimentally shown, which can be interpreted as a change of the major minimum due to an increases in the germanium concentration in the Si_1 – _ x Ge_ x layer. The effect of the multicomponent composition (electrons, light and heavy holes) of the electron–hole liquid on low-temperature photoluminescence spectra of Si/Si_1 ‒ _ x Ge_ x Si quantum wells is discussed.
Ориентационная зависимость магнитного момента микропроводов alpha-Fe(PrDy)(CoFeB)
Authors: Коплак O.В. , Дворецкая Е.В. , Таланцев А.Д. , Королев Д.В. , Валеев Р.А. , Пискорский В.П. , Денисова А.С. , Моргунов Р.Б.
Published: March 2020

The anisotropy of magnetization of α-Fe/(PrDy)(FeCo) core-shell microwires was studied at 300 K. The magnetization component of the α-Fe core directed along microwire axis and non-collinearly directed component of the microwire shell with correspondent saturation fields~ 100 Oe and > 10 kOe were separated. The directions of magnetizations of the shell and core of the microwire are differ by 170 grad.
Ангармонизм колебаний решетки и тепловые свойства твердых растворов Сd-=SUB=-1-x-=/SUB=-Sr-=SUB=-x-=/SUB=-F-=SUB=-2-=/SUB=-
Authors: Новиков В.В. , Митрошенков Н.В. , Кузнецов С.В. , Попов П.А. , Бучинская И.И. , Каримов Д.Н. , Кошелев А.В.
Published: March 2020

The temperature changes in the crystal lattice parameters a (T) of cadmium and strontium difluorides, as well as their mutual solid solutions Сd1-xSrxF2 (x = 0.23, 0.50), were studied experimentally at temperatures of 5-300 K. The temperature dependences of the unit cell volume of the fluorides studied were analyzed in the Debye-Einstein model . An increased effect of the anharmonism of lattice vibrations of solutions due to the disorder of the crystal structure on their thermal properties is established. The model parameters and characteristics of the anharmonic contribution are determined. Based on the data obtained, the concentration dependence of the thermal conductivity of Сd1-xSrxF2 solid solutions at T = 300 K was calculated in the Calaway model, compared with published experimental data. The possibility of assessing the thermal conductivity of single crystals of solid solutions of the studied system on the basis of data on the thermal properties of solution components obtained on powder samples is shown.
Особенности теплопереноса в гетероструктурах Al-=SUB=-x-=/SUB=-Ga-=SUB=-1-x-=/SUB=-N/GaN на сапфире
Authors: Чернодубов Д.А. , Майборода И.О. , Занавескин М.Л. , Инюшкин А.В.
Published: March 2020

Thermal conductivity of thin layers of AlxGa1-xN/GaN (0.05≤ x≤1) heterostructures on sapphire grown with molecular beam epitaxy has been measured. Thermal conductivity values of AlxGa1-xN и GaN thin films at room temperature have been obtained. Concentration dependence of thermal conductivity has been analyzed with the virtual crystal thermal conductivity model. Thermal transport in the structure considering local heating has been simulated numerically in order to find optimal structure layers` thicknesses allowing high thermal conductivity value.
Позиционно-чувствительные детекторы тепловых и холодных нейтронов с газовым конвертором -=SUP=-3-=/SUP=--=SUB=-2-=/SUB=-He (oбзор)
Authors: Кащук А.П. , Левицкая О.В.
Published: March 2020

Представлен краткий аналитический обзор позиционно-чувствительных детекторов тепловых и холодных нейтронов, выполненных на газовом конверторе 32He. Основное внимание уделено новым подходам и техническим решениям, определяющим тенденции развития методики. Ключевые слова: PSD, LPSD, MWPC, MSGC, MPGD, GEM, MHSP, ММ.
Моделирование влияния точечных мутаций на устойчивость белковых димеров на примере семейства белков Bcl-2
Authors: Кошлан T.B. , Куликов K.Г.
Published: March 2020

Pазработан новый метод, который позволит синтезировать пептиды с заданными физико-химическими свойствами, например, с высокой аффинностью к одному целевому белку, добиваясь низкой аффинности к другим белкам, и определять устойчивость белковых комплексов при точечных заменах аминокислотных остатков с учетом трехмерной структуры комплекса на примере семейства белков Bcl2, тем самым добиваясь точечной терапевтической избирательности при лечении различных патологий. Ключевые слова: константа диссоциации, трехмерная структура, энтропия, аминокислотный остаток.
Расчет межфазного массообмена в факеле распыла форсунки с учетом кризиса
Authors: Симаков Н.Н.
Published: March 2020

A numerical model and the results of calculation of the interfacial mass transfer in a two-phase flow formed by spraying a liquid in a gas with a nozzle are described. The basis of the proposed mathematical model is the differential equations of the nonstationary flow of a compressible medium supplemented by the equation of mass transfer from a gas to droplets. Going over to the difference analogues of the equations of continuity and phase motion, we used the well-known explicit Lax-Vendroff scheme. Herein, the axial profiles of the velocities of droplets and gas, concentrations of gas impurity in a free spray flow, as well as radial profiles of impurity concentrations in a two-phase flow through a cylindrical apparatus are calculated and presented accounting the early drag crisis of droplets, the mass-transfer crisis and the turbulent friction characteristics in gas discovered in previous experiments. Calculations show dependences of the volumetric gas flow, concentration of the gas admixture at the apparatus output, and the amount of impurity absorbed by a liquid on the height and cross-section area of the apparatus.
Теоретическое и экспериментальное исследование миниатюрной планарной замедляющей системы на диэлектрической подложке для лампы бегущей волны W-диапазона
Authors: Торгашов Р.А. , Рыскин Н.М. , Рожнев А.Г. , Стародубов А.В. , Сердобинцев А.А. , Павлов А.М. , Галушка В.В. , Бахтеев И.Ш. , Молчанов С.Ю.
Published: March 2020

The research results of a miniature meander planar slow-wave structure (SWS) for W-band traveling wave tube are presented. 3D computer simulation of the electrodynamic parameters of SWS has been carried out. A new technology of manufacturing of planar microstrip SWS has been presented. An experimental research of the S-parameters of an SWS has been carried out. The results show good agreement with the results of 3D simulation. The output characteristics of the TWT with sheet electron beam and planar SWS on dielectric substrate were simulated.
Позиционно-чувствительные детекторы тепловых и холодных нейтронов с тонкопленочным конвертором -=SUP=-10-=/SUP=--=SUB=-5-=/SUB=-B (обзор)
Authors: Кащук А.П. , Левицкая О.В.
Published: March 2020

Представлен краткий аналитический обзор позиционно-чувствительных детекторов тепловых и холодных нейтронов, выполненных на тонкопленочном конверторе 105B. Основное внимание уделено новым подходам и техническим решениям, определяющим тенденции развития методики. Ключевые слова: PSD, LPSD, MWPC, MSGC, MPGD, GEM, MM, Multi-Grid, Multi-Blade, CASCADE, μ-TPC.
Импульсно-периодический диффузный разряд с автоионизацией в потоке газа
Authors: Буранов С.Н. , Горохов В.В. , Карелин В.И. , Селемир В.Д. , Ширшин А.С.
Published: March 2020

Приведены результаты исследований импульсно-периодического диффузного разряда, возбуждаемого в потоке воздуха атмосферного давления, с автоионизацией в резко неоднородном кольцевом промежутке. Разряд является источником слабоионизованной неравновесной плазмы, в которой обеспечивается эффективный синтез оксида азота. Установлено, что формирование диффузных токовых каналов происходит последовательно по длине кольцевого промежутка в направлении потока воздуха в такт с частотой высоковольтных импульсов. Анализ экспериментальных данных дает основания предполагать, что эффект автоионизации обусловлен смещением отрицательных ионов кислорода, нарабатываемых в токовых каналах, а механизмом появления затравочных электронов в новых областях пробоя является отлипание электронов от ионов кислорода. Ключевые слова: импульсно-периодический диффузный разряд, кольцевой промежуток, автоионизация, синтез оксида азота.
Температурная зависимость эффективного поля магнитной анизотропии и ширины линии ферромагнитного резонанса поликристаллических сложнозамещенных гексагональных магнитноодноосных ферритов в диапазоне частот 25-67 GHz
Authors: Щербаков С.В. , Налогин А.Г. , Костишин В.Г. , Семенов А.С. , Адиатулина Н.Е. , Алексеев А.А. , Белоконь Е.А. , Тимофеев А.В. , Читанов Д.Н.
Published: March 2020

In the work in the frequency range 25 – 67 GHz the temperature changes of the effective magnetic anisotropy field and ferromagnetic resonance linewidth of the samples isotropic and anisotropic hexaferrite SrFe11.2Al0.1Si0.15Ca0.15O19 and anisotropic hexaferrite BaFe10.4Al1.4Si0.15Mn0.1O19 were studied. The samples obtained by ceramic technology with the pressing of the raw blanks in a magnetic field of 10 kOe. The studies were carried out in the temperature range+25 – +85 ºC. It was found that in the specified temperature range, the change in magnetic anisotropy is 9.8 Oe/ºC for barium hexaferrite and 4.2 Oe/ºC for strontium hexaferrite, and the change in ferromagnetic resonance linewidth is 12.2 Oe/ºC for barium hexaferrite and 10 – 12.3 Oe/ºC for strontium hexaferrite.
Поляритонные возбуждения в неидеальной двухподрешеточной цепочке микропор
Authors: Румянцев В.В. , Федоров С.А. , Гуменник К.В. , Паладян Ю.А.
Published: March 2020

Исследована зависимость дисперсионных характеристик поляритонных возбуждений в неидеальной 1D-решетке микропор от концентрации дефектов структуры, связанных с вариацией положений микропор, содержащих в одной из подрешеток квантовые точки. Показано, что в результате наличия данных структурных дефектов в 1D-двухподрешеточном массиве микропор можно добиться необходимого изменения энергетической структуры поляритонных возбуждений и, следовательно, оптических свойств исследуемой системы, обусловленных перестройкой электромагнитного спектра. Ключевые слова: неидеальная 1D-решетка микропор-резонаторов, поляритонные возбуждения, квантовые точки, приближение виртуального кристалла.
Электрическая площадь импульса при разделении и слиянии зарядов в вакууме
Authors: Розанов Н.Н.
Published: March 2020

Analytically determined is the distribution of the electric area of the pulse generated by the charges arising from the ionization of an initially uncharged microobject, which, after recombination caused by the Coulomb attraction of charges, is again uncharged. It is shown that when approaching the points at which the instantaneous velocity of the particles turns to 0, the electric area grows infinitely according to a power law (the "-3/2 rule").
Квантово-каскадные лазеры с распределенным брэгговским отражателем, сформированным методом ионно-лучевого травления
Authors: Бабичев А.В. , Пашнев Д.А. , Гладышев А.Г. , Денисов Д.В. , Вознюк Г.В. , Карачинский Л.Я. , Новиков И.И. , Митрофанов М.И. , Евтихиев В.П. , Фирсов Д.А. , Воробьев Л.Е. , Пихтин Н.А. , Егоров А.Ю.
Published: March 2020

Single-frequency lasing of quantum-cascade lasers with a distributed Bragg reflector formed by the focused ion beam milling technique in the layers of the upper cladding of the waveguide is demonstrated. The active region In0.53Ga0.47As/Al0.48In0.52As is formed based on the scheme with two-phonon lower energy level depopulation in the cascade. Single-frequency lasing at a temperature of 280 K corresponded to a radiation wavelength of 7.74 μm; the side mode suppression ratio (SMSR) was 24 dB.
Генерация сверхизлучения импульсным механическим воздействием
Authors: Александров А.И. , Шевченко В.Г. , Александров И.А.
Published: March 2020

The effect of pulsed mechanical activation of radio-frequency superradiation in the parametric mode is established: when an external rheological explosion under high pressure acts on a paramagnetic composite --- a system of crossed spins based on binuclear complexes Co (QH) _2-O-Co (QH) 2 or Mn (QH) _2-O-Mn (QH) 2 (QH --- ligand based on 3,6-di-tert-butylpyrocatechol) in a polystyrene matrix. A possible method for processing data on pulsed mechanical action and a possible explanation of the effect are proposed.
Кинетика роста зародыша из нанофазы
Authors: Дубровский В.Г.
Published: March 2020

We present a theoretical analysis of the growth kinetics of a nucleus from a nano-sized mother phase with a restricted amount of material in the presence of the stopping effect due to the depletion of supersaturation. Such a regime is typical for GaAs nanowires grown by the vapor-liquid-solid mechanism from a Ga droplet and is observed by in situ growth monitoring inside a transmission electron microscope. An analytical solution is obtained for the time-dependent size of the nucleus and atomic concentration in a nano-phase. A principally new time-scale hierarchy is found, whereby the entire growth process id divided into 3 stages – (1) fast nucleus growth to the stopping size, (2) slow nucleus growth at the rate of refill of a mother phase, and (3) further refill of a mother phase to resume the initial supersaturation. A general criterion is formulated for observing the stopping effect depending on the size of a nano-phase.
Пылевая плазма в сильно неоднородном магнитном поле
Authors: Карасев В.Ю. , Дзлиева Е.С. , Павлов С.И. , Новиков Л.А. , Машек И.Ч.
Published: March 2020

The paper presents for the first time studies of dusty plasmas formed in a glow discharge in a region of a strongly inhomogeneous magnetic field. The inhomogeneity of the magnetic field is estimated as 0.2 T/cm. A steady dust trap has been detected. The geometric characteristics of the plasma-dust structure were determined; the angular velocity of rotation was measured in several sections perpendicular to the axis of the discharge tube. The mechanism of rotation of the plasma-dust structure is proposed, quantitative estimates are made that confirm the experimental data.
CuBr-лазер большого объема c возможностью непрерывного управления энергией генерации
Authors: Тригуб М.В. , Троицкий В.О.
Published: March 2020

The paper presents the results of research and development of the copper bromide active element with continuous control of the each pulse energy. Distinctive features are the implementation of the continious control mode for a large-volume gas discharge tube (more than 1.5 L) and the radiation formation by an unstable resonator. In this case, a hydrogen-containing additive was used to modify the plasma kinetics in order to increase the radiation power. The control was carried out through the use of an additional preionization pulse. The dependences of the generation power on each line on the preionization pulse energy and the time delay between this pulse and the excitation pulse are obtained. It is shown that in the developed layout, the determining factor in pulse energy controlling is the population of metastable levels of copper atoms.
Body Weight and Blood Biochemical Changes Following Nutritional Supplementation in Prepubertal Jaffrabadi Buffalo (Bubalus bubalis) Heifers
Authors: Raval1 R J , Vala K B , Kalariya V A , Dhami A J , Kavani F S
Published: March 2020

The high plan of nutrition right from an early age is believed to enhance ovarian activity and early onset of puberty in heifers. This study was therefore conducted to know the body weight, ovarian and blood biochemical changes in nutritionally supplemented and control
groups of prepubertal Jaffrabadi buffalo (Bubalus bubalis) heifers. A total of 12 animals of 30 ± 2 month's age and the identical body
weight of 380–410 kg from Cattle Breeding Farm, JAU, Junagadh were utilized for this study. They were randomly divided into two equal
groups of 6 animals in each treatment and control groups. The heifers of the treatment group were supplemented with bypass fat (100
g), bypass protein (950 g) and chelated mineral mixture (50 g) over the routine farm feeding practices of control group, and its effect
on body weight gain and blood biochemical profiles were studied at a monthly interval during 6 months of experimental period. The
overall effect of nutritional supplementation on animals body weight, blood glucose and total cholesterol over the control group was
statistically non-significant (p greator than 0.05) yet beneficial. The plasma total protein levels in the supplemented group increased with a duration
of supplement and levels were significantly (p less than 0.05) higher over the control group. The ovarian dynamics evaluated by transrectal
ultrasound during last three months of the study revealed an increasing number of growing follicles greator than 4 mm in diameters (5.00 ± 0.13
to 6.67 ± 0.40), without significant variation in diameters of largest follicles (9.14 ± 0.45 to 10.27 ± 0.85 mm) between groups or periods.
However, none of the heifers exhibited behavioral signs of estrus during 6 months study, in spite of the establishment of cyclicity with
the presence of developed follicles, or CLs suggesting silent ovulation, at 36 ± 2 months of age in this breed.
Ovariohysterectomy: A Salvage Method in Welfare of Stray Cattle: A Clinical Case Report of Five Animals
Authors: Borakhatariya D N , Karangiya V K , Ribadiya N K
Published: March 2020

With the hike of the human population in metro cities, problems of stray orphan cattle have also increased simultaneously. Such animals when feeding on roadside litter and plastic garbage, don’t gain optimum nutrition and because of that suffer from many diseases. In such animals when a reproductive problem arises, it remains untreated for a longer duration and as time elapsed certain reproductive conditions such as cervicovaginal prolapse could not be treated by ordinary methods due to fibrosis (Tyagi and Singh, 2002). Present communication documents successful management of long-standing cases of reproductive organ’s prolapse via per vaginum ovariohysterectomy in stray cattle.
Surgical Management of Secondary Uterine Inertia in Two Bitches
Authors: Raval R J , Vala K B , Parmar K H , Talekar S H
Published: March 2020

Primary or secondary uterine inertia is due to lack of normal physiological uterine contraction during or after parturition. Secondary uterine inertia is commonly observed in bovine, however, it is comparatively less reported in canine. In certain breeds of dog such as the Scotch terrier or Dachshund secondary uterine inertia may occur spontaneously early in the second stage of parturition. Usually, one or two fetuses are expelled normally and then labor ceases even though more fetuses are present in the uterus (Roberts, 1982). The present report places on record the difficult whelping due to secondary uterine inertia and its radiographic diagnosis and successful surgical management in 2 bitches.
Prevalence, Risk Factors and Differential Diagnosis of Cystic Ovarian Degeneration in Crossbred Cows
Authors: Chauhan1 JH , Hadiya2 KK , Dhami AJ
Published: March 2020

The present study was conducted under field conditions on >90 days postpartum HF crossbred cows with cystic ovaries (n = 58). The
diagnosis was confirmed by history and trans-rectal palpation and ultrasonographic examinations twice at weekly interval using 5.0–7.5
MHz frequency probe and was later authenticated with plasma progesterone assay and treatment response. The animals with follicular
cysts were randomly treated with either conventional ovsynch or ovsynch + CIDR protocol with fixed time AI (n = 10 each), and those
with luteal cysts with either double PG injections 11 days apart or modified Ovsynch protocol (n = 16 each). Among 58 cystic cows,
the highest incidence (62.07 %) of the ovarian cyst was recorded in the age group of 5–7 years followed by above 7 years (36.21%) and
3–5 years (2.00%). The incidence was highest among cows of 3rd or more parity (70.69%) followed by 2nd parity (29.31%), and no case
was seen in primiparous cows. Of the total 36.21% were follicular type cyst and 63.79% luteal type cysts. The right ovary had a high
incidence of the cyst (51.72%) followed by the left ovary (36.21%), and bilateral (12.07%). Based on rectal palpation, the cystic ovary was
classified to have follicular cyst in 36.21% (21/58) cases and luteal cysts in 63.79% (37/58). Ultrasound examination showed follicular
and luteal cysts as 27.59% and 72.41%, whereas plasma P4 (less than/greator than 1 ng/mL) analysis revealed this as 20.69% and 79.31%, respectively.
The clinical diagnosis became more accurate with a combination of per rectal palpation and USG and was further improved by plasma
progesterone assay. The mean diameters and a wall thickness of cysts varied highly significantly (p less than 0.01) between groups/protocols.
The conception rates at induced estrus with FTAI in cows under ovsynch, ovsynch + CIDR, modified ovsynch and double PG protocols
were 50.00, 40.00, 50.00 and 43.75 percent, respectively. It is thus concluded that in crossbred cows luteal cysts are more common than
follicular cysts, particularly in prime aged animals of 3rd or 4th parity with more of left ovarian involvement. The differentiation of cyst
type is best achieved with the combined use of USG and/or plasma progesterone assay with rectal palpation, and that ovsynch protocol
appeared promising for the treatment of follicular cysts and Modified Ovsynch for luteal cysts.