bluuebunny/crossref_metadata_2025 huggingface dataset:
Antiviral Drug Targets of Single-Stranded RNA Viruses Causing Chronic Human Diseases
Authors: Dinesh Dhurvas Chandrasekaran , Tamilarasan Selvaraj , Rajaram Kaushik , Bouřa Evžen
Published: September 2019

Ribonucleic acid (RNA) viruses associated with chronic diseases in humans are major
threats to public health causing high mortality globally. The high mutation rate of RNA viruses helps
them to escape the immune response and also is responsible for the development of drug resistance.
Chronic infections caused by human immunodeficiency virus (HIV) and hepatitis viruses (HBV and
HCV) lead to acquired immunodeficiency syndrome (AIDS) and hepatocellular carcinoma respectively,
which are one of the major causes of human deaths. Effective preventative measures to limit
chronic and re-emerging viral infections are absolutely necessary. Each class of antiviral agents targets
a specific stage in the viral life cycle and inhibits them from its development and proliferation. Most
often, antiviral drugs target a specific viral protein, therefore only a few broad-spectrum drugs are
available. This review will be focused on the selected viral target proteins of pathogenic viruses containing
single-stranded (ss) RNA genome that causes chronic infections in humans (e.g. HIV, HCV,
Flaviviruses). In the recent past, an exponential increase in the number of available three-dimensional
protein structures (>150000 in Protein Data Bank), allowed us to better understand the molecular
mechanism of action of protein targets and antivirals. Advancements in the in silico approaches paved
the way to design and develop several novels, highly specific small-molecule inhibitors targeting the
viral proteins.
Prioritizing Key Duration Estimation Accuracy Factors in Highway Infrastructure Projects Using Fuzzy AHP
Authors: Meharie Meseret Getnet , Gariy Zachary C. Abiero , Mutuku Raphael Ngumbau Ndisya , Mengesha Wubshet Jekale
Published: September 2019

Background:

At the early phase of project development, highway engineering estimators seek to determine the duration of highway construction projects for the purpose of construction planning and administration. Thus, it is vital to study and analyze the estimation accuracy factors of highway construction project duration. In this regard, several studies have been conducted to identify and analyze the estimation accuracy factors of project duration in various ways to improve the estimation and management performance of all the contracting parties. However, very less effort has been devoted to evaluating the duration estimation accuracy factors in the case of the highway construction industry under fuzzy environment.

Objective:

This paper aims to analyze and prioritize the critical factors that potentially affect the duration estimation accuracy of the highway construction projects in Ethiopia under fuzzy environment.

Methods:

An extensive review and discussions with highway engineering experts were carried out to explore and identify the duration estimation accuracy factors. The study data collection process consists of two stages. The first stage is to conduct a questionnaire survey. Whereas, the second stage is to carry out the pair-wise comparison matrix to capture the imprecision and vagueness in subjective responses. Then, a λ-cut set method to reduce the initial list of factors and exploratory factor analysis was used to classify the reduced set of factors into smaller groups. Finally, a fuzzy hierarchy process algorithm with the use of triangular fuzzy numbers was presented for prioritizing critical factors.

Results:

A cut -off value, λ = 0.95, was verified which resulted in the identification of critical accuracy factors. Accordingly, 12 critical factors were opted and categorized as a cluster of similar items into 5 groups. Finally, the analytical results obtained from fuzzy AHP algorithm revealed that project complexity, project size, bridge type and complexity were found to be the four top-ranked factors based on the global priority weight.

Conclusion:

These factors must be a serious concern in estimating and administering the contract and the duration of highway construction projects at the early phases of project development so that the time deviation upon the completion of the project can be minimized.
Low Self-Esteem and Selfie Posting Among Young Women
Authors: Biolcati Roberta
Published: September 2019

Background:

Self-esteem is a critical factor in online impression management strategies and could play a crucial role in explaining women’s selfie-posting behaviours. Previous works examining relationships between self-esteem and self-presentation on social media have yielded controversial results.

Objective:

This study was performed to clarify the relationship between self-esteem and the frequency of taking and posting own, group and partner selfies on Social Networking Sites (SNS).

Methods:

A sample of 692 Italian young women (18-28 years old) completed questionnaires on self-esteem, satisfaction with life, body satisfaction and selfie posting bahaviours. The low self-esteem group was compared with the high self-esteem group.

Results:

Results showed that women with low self-esteem are more dissatisfied with their body image and life and significantly they post fewer types of selfies compared to women with high self-esteem.

Conclusion:

Findings from this study provide new insights into the relation between self-esteem and selfie impression management strategies.
Development of Filipino Nurse Educator’s Wellbeing Survey (FNEWS): An Exploratory Sequential Mixed Methods Study
Authors: Salvador Jordan T. , Alqahtani Friyal M. , Al-Garni Rima S. Sareh
Published: September 2019

Background:

The role of a nurse educator is a vital component in the management process of teaching and learning development of students. Ensuring excellent wellbeing for nurse educators may lead to increased job satisfaction and work performance.

Objective:

The objective of this study was to develop a survey tool that measures the wellbeing of Filipino nurse educators working in four Gulf Cooperation Council (GCC) countries.

Methods:

Three-phase sequential approach was obtained. The investigation started with a qualitative investigation of 20 Filipino nurse educators based from Saudi Arabia, United Arab Emirates, Oman, and Bahrain followed by a development of survey tool measuring the Filipino nurse educator’s wellbeing. The survey tool was distributed among 112 participants in Saudi Arabia. Data were analyzed and interpreted by means of a Colaizzi method for qualitative and descriptive statistics using SPSS for quantitative measures.

Results:

All the themes emerged from the qualitative phase were discussed from the gathered review of literature and studies. Themes, contextual categories, and significant statements were used as survey constructs measuring the wellbeing of the participants. Moreover, a valid and reliable survey tool called ‘Filipino Nurse Educator’s Wellbeing Survey’ (FNEWS) was developed and surveyed among the Filipino nurse educators in Saudi Arabia, revealing an ‘acceptable’ level of wellbeing.

Conclusion:

Knowing the level of wellbeing of nurse educators will be an effective way to provide the competency needed to address burnout, low job satisfaction, and compassion fatigue, thereby increasing the likelihood of safeguarding the welfare of the nurse educators.
Age-Related Argonaute Loading of Ribosomal RNA Fragments
Authors: Guan Lingyu , Grigoriev Andrey
Published: September 2019

Background:

Accumulating evidence points to the functional roles of rRNA derived
Fragments (rRFs), often considered degradation byproducts. Small RNAs, including miRNAs and
tRNA-derived Fragments (tRFs), have been implicated in the aging process and we considered rRFs
in this context.

Objective:

We performed a computational analysis of Argonaute-loaded rRFs in Drosophila melanogaster
to study rRF changes with age. We determined rRF abundance in Ago1 and Ago2 at 3 and 30
days to identify Ago1-guided and Ago2-guided fragments. We searched for putative seed sequences
in rRFs based on frequent matches of sliding k-mer windows to the conserved regions of 12 Drosophila
genomes. We predicted putative targets (containing matches to seeds identified in four rRFs)
and studied their functional enrichments using Gene Ontology.

Results:

We identified precise cleavage sites of distinct rRF isoforms from both nuclear and mitochondrial
rRNAs. The most prominent rRF isoforms were enriched in Ago2 at 3 days and that loading
strongly decreased with age. For less abundant rRFs, loading of Ago2-guided rRFs generally increased
in Ago2, whereas Ago1-guided rRFs revealed diverse patterns. The distribution of seed
matches in targets suggested that rRFs may bind to various conserved regions of many genes, possibly
via miRNA-like seed-based mechanisms.

Conclusions:

Our observations suggest that rRFs may be functional molecules, with age-dependent
Argonaute loading, comparable to that of miRNAs and tRFs. The putative rRF targets showed significant
enrichment in developmental processes and biological regulation, similar to tRFs and consistent
with a possible involvement of these newly identified small RNAs in the Drosophila aging.
Modeling and Simulation for Multiple Damage Progression of Tank-to- Engine Fuel Feed System
Authors: Wenjuan Li , Haiqiang Liu , Bo Zhang
Published: September 2019

Background:

A centrifugal vane pump driven by a three-phase AC motor is a key component
for modern equipment. Therefore, its condition directly affects the operating and safety performance
of the system. Modeling and simulation are effective methods for the system analysis.

Methods:

A mathematical model of a Tank-to-Engine Fuel Feed System (T-EFFS) is designed
based on its phased-mission behavior and structure redundancy. Both of the damage modes that
arise frequently in a given type of system are tracked: the fuel feed pump seal damage due to fatigue
and the vane damage due to corrosion. Then, a multiple degradation T-EFFS model is established to
simulate the fuel pressure at the system outlet under different damage modes. The morphological
spectrum decrement index is used to describe the damage of the system.

Results:

The results show that the T-EFFS model can describe the phased-mission behavior of the
system and meet the requirement of the fuel flow rate for the entire mission profile. Then, the decrease
in the fuel pressure of the T-EFFS with the cumulative effects of vane damage and crack
growth under different behavior modes is simulated along its life span.

Conclusion:

This work aims to provide a model and data support for a subsequent investigation.
The results can be used to fit the health background curve of the system, predict the performance degradation
trend of the system at given life points, and further evaluate its remaining service life.
Uso y manejo de la vegetación leñosa en el fundo legal de Yaxcabá, Yucatán, México
Authors: Rodríguez-Sánchez Perla Victoria , Levy-Tacher Samuel Israel , Ramírez-Marcial Neptalí , Estrada-Lugo Erin Ingrid Jane
Published: September 2019

Antecedentes y Objetivos: El fundo legal (FL) es una franja de vegetación forestal que delimita periféricamente a los poblados, provee de múltiples servicios ecosistémicos y forma parte de las Reservas Forestales Comunitarias Mayas de la Península de Yucatán. El objetivo de este estudio fue describir las formas de uso y manejo de la vegetación leñosa del FL por parte de los habitantes de la comunidad de Yaxcabá, Yucatán.
Métodos: El FL se dividió en tres secciones a partir del número de caminos identificados. En cada sección se establecieron ocho parcelas de muestreo de 400 m2 (20 x 20 m) y ocho parcelas más en vegetación madura (VM). En cada parcela se midió el diámetro de los tocones y se determinó su identidad taxonómica. Se estimó la riqueza, densidad y área basal y se contrastó con sitios con VM fuera del FL y con poca evidencia de aprovechamiento. Se aplicó una encuesta cerrada a la población para detallar las formas de uso local y manejo que los habitantes hacen en el FL.
Resultados clave: Se registraron 58 especies útiles que comprenden 42 géneros y 22 familias de angiospermas, donde Fabaceae, Polygonaceae y Ebenaceae fueron las familias más abundantes. El aprovechamiento comprende una amplia variedad de especies y se cosechan pocos individuos pero el aprovechamiento varía entre rumbos dentro de la comunidad; este aprovechamiento no afecta notablemente la composición de especies entre el FL y la VM.  
Conclusiones: Aun cuando existen secciones del FL en las que su cobertura vegetal se encuentra degradada, las estrategias de aprovechamiento actual permiten la permanencia y conservación de la composición de especies a nivel local. La intensidad de aprovechamientos en el FL se ve reflejada por una mayor cantidad de caminos y la distancia que hay entre ellos y los recursos forestales que utilizan.
Асимметричная генерация в сверхизлучающем лазере с симметричным низкодобротным резонатором
Authors: Кочаровский Вл.В. , Кукушкин В.А. , Тарасов С.В. , Кочаровская Е.Р. , Кочаровский В.В.
Published: September 2019

On the basis of numerical solution to the Maxwell-Bloch equations within an one-dimensional two-level model of a superradiant laser with a symmetric cavity where a photon lifetime is less than an incoherent relaxation time of the optical dipole oscillations of active centers, we find that a spontaneous asymmetric generation of the counter-propagating waves is possible under a continuous homogeneous pumping of an active medium. We show that such a phenomenon of a symmetry breaking of the spatial profiles of the counter-propagating waves of an electromagnetic field as well as the polarization and population inversion of an active medium in the considered case of a weak inhomogeneous broadening of an operating transition is caused by an asymmetric half-wavelength nonlinear grating of the population inversion of the transition’s energy levels which is produced by these waves.
Двухфононная релаксация возбужденных состояний акцепторов бора в алмазе
Authors: Бекин Н.А.
Published: September 2019

The relaxation of holes in the excited states of boron acceptors in diamond is theoretically investigated when two optical phonons are emitted. An electron-like Hamiltonian with an isotropic effective mass was used to describe the wave function of the acceptor states. The wave function of the ground state was found by the quantum defect method. The transition probability was calculated in adiabatic approximation. The dispersion law of phonons was considered isotropic, and the frequency of phonons is quadratically dependent on the wave vector module, with the maximum value, omegamax, achieved in the center of the Brillouin zone, and the minimum, omegamin, at the edge of the Brillouin zone. The high sensitivity of the rates to the characteristic of phonon dispersion, omegamax-omegamin, especially for the transition energy, ET, in the 2homegamin≤ ET<homegamin +homegamax interval was revealed. Depending on the transition energy and dispersion of phonons, the rate of two-phonon relaxation in the low-temperature limit varies from ultra-low values (less than 108 s-1) near the threshold, ET=2homegamin, to ultra-high values (more than 1012 s-1) in the "resonance" region homegamin+homegamax≤ ET≤2homegamax.
Узкозонные гетероструктуры InAs-=SUB=-1-y-=/SUB=-Sb-=SUB=-y-=/SUB=-/InAsSbP (y=0.09-0.16) для спектрального диапазона 4-6 μm, полученные методом МОГФЭ
Authors: Романов В.В. , Иванов Э.В. , Моисеев К.Д.
Published: September 2019

AbstractAsymmetric n -InAs/InAs_(1 – _ y )Sb_ y / p -InAsSbP heterostructures with a narrow-gap active layer and a composition range y = 0.09–0.16 were grown by vapor phase epitaxy from metalorganic compounds. Room-temperature electroluminescence was observed at a wavelength of up to λ = 5.1 μm at a spectral maximum. The study of low-temperature electroluminescence spectra provided the possibility to establish the existence of two radiative recombination channels caused by the nature of the InAsSb/InAsSbP heterointerface. The effect produced by the chemistry of the active layer on the composition of the grown barrier layer and the formation of the InAsSb/InAsSbP heterojunction with an increase in the antimony content in the InAsSb solid solution was demonstrated.
Пироэлектрический и электрокалорический эффекты в твердых растворах PMN-PbTiO-=SUB=-3-=/SUB=--SrTiO-=SUB=-3-=/SUB=-
Authors: Смирнова Е.П. , Сотникова Г.Ю. , Зайцева Н.В. , Гаврилов Г.А. , Сотников А.В.
Published: September 2019

Studies of pyroelectric and electrocaloric effects as well as dielectric properties in a bias electric field in solid solutions of lead-strontium magnoniobate-titanate have been carried out. The features of the temperature and field dependences of the pyroelectric and electrocaloric effects are discussed.
Влияние температуры на люминесцентные свойства керамики MgAl-=SUB=-2-=/SUB=-O-=SUB=-4-=/SUB=- : Dy, синтезированной методом искрового плазменного спекания
Authors: Полисадова Е.Ф. , Ваганов В.А. , Валиев Д.Т. , Степанов С.А. , Пайгин В.Д. , Двилис Э.С. , Хасанов О.Л.
Published: September 2019

MgAl2O4:Dy3+ transparent ceramics were synthesized by Spark Plasma Sintering technique. The optical properties, photo- and cathodoluminescence, and luminescence decay kinetics were studied. The effect of temperature on the spectral and kinetic characteristics of luminescence was investigated. There are several emission bands in emission spectra responsible for Dy3+ ions at 458 (4I15/2 - 5H15/2), 480 nm (4F9/2 - 6H15/2), 573 nm (4F9/2 - 6H13/2), 665 nm (4F9/2 - 6H11/2), 750 nm (4F9/2 - 6H9/2), chromium Cr3+ (2Eg - 4A2g), and internal defects such as F+ centers (460 nm) were observed. The temperature quenching of the luminescence in the visible spectral range is observed when the temperature varies from 100 to 300 K. It is shown that in the MgAl2O4: Dy ceramics, the quenching patterns for impurity and intrinsic centers differ. The mechanisms of temperature quenching are discussed.
Люминесцентные свойства боросиликатного стекла, легированного церием
Authors: Валиев Д.Т. , Степанов С.А. , Yao G. , Zhou Y.
Published: September 2019

ABS – BGP (Al2O3 – B2O3 – SiO2 – BaCO3 – Gd2O43 – P2O5) glasses doped with different Ce3+ concentrations were prepared by glass melting method. Optical, structural and luminescent properties have been characterized. Emission in the spectral range of 350–550 nm, associated with radiation transitions of Ce3+ ions was recorded. The luminescence decay kinetics is characterized by two components. The fast component is 45–90 ns. For the slow component, a decrease in the decay time from 4 to 0.9 us with increasing cerium ion concentration is shown. Based on the luminescence spectra, an assumption about the existence of various emitting states of the Ce3 + ion in borosilicate glass was made.
Критические свойства в модели Изинга на треугольной решетке с переменным межслойным обменным взаимодействием
Authors: Муртазаев А.К. , Рамазанов М.К. , Бадиев М.К.
Published: September 2019

The Monte Carlo replica algorithm studies of phase transitions and critical phenomenaofthe layered triangular antiferromagnetic Ising model withvariable interlayer exchange interaction. Investigations were carried out for the ratios of the value of the intralayerJ1 and interlayer J2 exchange interactions in the range of values r = J2 / J1 = 0.01 ÷ 1.0. It was found that in the above range r is observed second-order phase transition.Static critical exponents for the heat capacityα, susceptibility γ, order parameter β, correlation radius ν, and the Fisher exponent ηare computed by means of the finite-size scaling theory. It is shown that the universality class of the critical behavior of the model is maintained in the range of 0.05 <r≤1.0.The results obtained suggest that3D frustrated Ising models on stacked triangularlattice with interlayer-to-intralayer exchange ratio 0.05<r≤1.0. preserves the universality class of criticalbehavior. At lower r, a crossover from 3D to 2D criticalbehavior is observed.
Термодинамические и магнитные свойства двумерной анизотропной модели Изинга с конкурирующими взаимодействиями
Authors: Муртазаев А.К. , Ибаев Ж.Г.
Published: September 2019

The two-dimensional anisotropic Ising model was studied with competing interactions on a square lattice using Monte-Carlo methods using the Wang-Landau algorithm. The temperature dependences of the main thermodynamic and magnetic parameters are calculated. The distinctive features of the temperature dependences of these parameters are shown for different values of the competing interaction. The graphs of the dependence of the wave number of modulated structures on the ratio of the parameters of exchange interactions are plotted. Built phase diagram of the model. Interpolating the phase boundaries of the diagram, the coordinates of the Lifshchits point and phase localization areas with different wave vector values are calculated.
Влияние температуры синтеза на микроструктуру и электрофизические свойства пленок BST 80/20
Authors: Афанасьев М.С. , Киселев Д.А. , Левашов С.А. , Сивов А.А. , Чучева Г.В.
Published: September 2019

The paper shows the effect of synthesis temperature on the microstructure and electrophysical properties of ferroelectric films of composition Ba0.8Sr0.2TiO3 when formed on silicon substrates with a platinum sublayer. On the basis of electrophysical and topographical measurements, a conclusion is made about the effect of the temperature of synthesis of ferroelectric films on their properties.
Старение и разрушение (пробой) полимерных пленок в переменном электрическом поле
Authors: Закревский В.А. , Пахотин В.А. , Сударь Н.Т.
Published: September 2019

An explanation is proposed for the difference in the electrical strength properties of polymers in DC and AC fields. Energy release during recombination of electrons and holes injected into a polymer dielectric is considered as a factor accelerating the process of electrical aging of these dielectrics in AC field.
It is shown that the nonradiative relaxation of electronic excited states, which causes bond breaks in macromolecules and the formation of free radicals, leads to the formation of deep electron traps in a polymer dielectric, as a result of which the ionization of macromolecules in the electric field is accelerated due to electron transitions into these traps. In solid-state plasma, a shielding effect occurs, leading to a decrease in the ionization potential of molecules. As a result, the ionization rate of macromolecules increases, i.e. the rate of formation of charge carriers, which leads to a decrease in the electrical life time of the polymer dielectric in AC field compared with the life time of polymers in DC field.
Незаполненные электронные состояния ультратонких пленок дифенилфталида на поверхности высокоупорядоченного пиролитического графита
Authors: Комолов А.С. , Лазнева Э.Ф. , Герасимова Н.Б. , Соболев В.С. , Пшеничнюк С.А. , Асфандиаров Н.Л. , Крайкин В.А. , Handke B.
Published: September 2019

AbstractThe results of diagnostics of the atomic composition of a diphenylphthalide (DPP) film thermally precipitated in vacuum by the of X-ray photoelectric spectroscopy (XPS) method are presented. The results of examination of the unoccupied electronic states of the ultrathin DPP films with the thickness up to 10 nm on the surface of the highly oriented pyrolytic graphite (HOPG) by the total current spectroscopy (TCS) method in the energy range from 5 to 20 eV above E _F are presented. In this range, the main maxima in the total current spectra are identified. The analysis of the TCS results with consideration of the theoretical calculation results has shown that the low-energy maxima observed at the energies from 6 to 7.5 eV are induced predominately by π* electron orbitals of DPP films. The values of the energy E _vac in relation to E _F, i.e., of the electron work function in the DPP films at the film thickness of 5–10 nm, are found experimentally at a level of 4.3 ± 0.1 eV. The negative charge transfer from an organic film to the substrate corresponds to the formation of the HOPG/DPP boundary potential barrier during the thermal deposition of the DPP film.
Высокотемпературная теплоемкость и термическое расширение FeTa-=SUB=-2-=/SUB=-O-=SUB=-6-=/SUB=-
Authors: Гуляева Р.И. , Петрова С.А. , Чумарев В.М. , Мансурова А.Н.
Published: September 2019

The heat capacity of the synthesized FeTa2O6 iron tantalate was measured in the temperature range of 323-1103 K by the ratio method using a thermal analyzer with combined thermogravimetry and scanning calorimetry. The phase transition temperatures were determined. Structural changes and thermal expansion of the oxide in the range of 300-1173 K were studied by high-temperature X-ray diffraction. The temperature dependences of the unit cell parameters were approximated by third-degree polynomials. From the data obtained, the values of thermal expansion coefficients and anisotropy factors were calculated.
Влияние типа проводимости и уровня легирования кристаллов кремния на размеры каналов пор, формирующихся в них при анодном травлении в растворах плавиковой кислоты
Authors: Зегря Г.Г. , Улин В.П. , Зегря А.Г. , Улин Н.В. , Михайлов Ю.М.
Published: September 2019

AbstractIn this paper, we discuss causes of the multidirectional effect of changes in the concentrations of free charge carriers in silicon crystals of p - and n -type conductivity on the transverse dimensions of pores formed as a result of anodic etching in hydrofluoric acid solutions, as well as the effect of anodic current density on pore size. The observed dependences are explained based on the concepts of electrochemical pore formation in semiconductor crystals as self-organizing cooperative processes accompanied by the injection of electrons from the chemical reaction region at the pore advancement front. Differences in the size of pores forming at the same current density in crystals differing in type and concentration of free charge carriers are associated with the effective temperature of the front of the cooperative chemical reaction at the bottom of germinating pores. This temperature, in turn, correlates with the power density of thermal energy released in the near-surface region of the etching crystal, either due to recombination processes for a p -type semiconductor or direct or indirect energy transfer from hot electrons to lattice vibrations in the case of a n -type semiconductor. The characteristic relaxation times of injected nonequilibrium electrons were calculated depending on the concentrations of the majority charge carriers in silicon crystals of both types of conductivity and the corresponding thicknesses of the regions of relaxation energy release. The revealed patterns of concentration changes in the power density of heat release in the near-frontal region of etching silicon crystals of p - and n -type conductivity are in good agreement with observed changes in the size of germinating pores.
Исследование возможностей метода газофазной эпитаксии из металлорганических соединений для изготовления тонких слоев InAs/GaSb
Authors: Левин Р.В. , Пушный Б.В. , Федоров И.В. , Усикова А.А. , Неведомский В.Н. , Баженов Н.Л. , Мынбаев К.Д. , Павлов Н.В. , Зегря Г.Г.
Published: September 2019

Capabilities of Metal Organic Chemical Vapor Deposition (MOCVD) method for fabrication of multi-layer InAs/GaSb structures with thin (1-2 nm) layers on GaSb substrates were studied. Properties of fabricated structures were studied by transmission electron microscopy and photo- and electro-luminescence. It was found that during growth, two solid solutions GaInAsSb of different compositions were formed in the active region of the structures. The system obtained is characterized by emission at the wavelength of 4.96 µm at the temperature 77 K. Our results demonstrate new capabilities of MOCVD method for bandgap engineering of semiconductor structures based on InAs/GaSb and designed for optoelectronic devices for infrared wavelength range.
Математическая модель распространения лазерного излучения в морской воде
Authors: Костылёв Н.М. , Колючкин В.Я. , Степанов Р.О.
Published: September 2019

AbstractBased on the well-known models of optical properties of a seawater layer in the spectral range of 530–550 nm, a mathematical model of the propagation of laser radiation is proposed. The mathematical model is obtained by solving radiative transfer equation for a narrow beam using a few-parameter approximation of the scattering indicatrix of the seawater layer. The model makes it possible to determine the spatial distribution of irradiance at a given distance from the laser radiation source by the known Secchi disk depth. The results of numerical experiments for water areas with known optical properties are given.
Оценка соотношения энергий излучения Вавилова--Черенкова и катодолюминесценции, возбуждаемых электронным пучком в алмазе
Authors: Бакшт Е.Х. , Артемов К.П. , Бураченко А.Г. , .Тарасенко В.Ф
Published: September 2019

AbstractThe ratio between energies of Vavilov–Cherenkov radiation and cathodoluminescence excited by an electron beam in diamond samples is determined taking into account electron scattering in these samples, energy distribution of beam electrons, ionization losses of the electron energy, and dispersion of the diamond refractive index. Experimental results on measuring spectral characteristics of the glow of natural and synthetic diamond samples under the action of a subnanosecond electron beam with electron energy of up to 200 keV are presented. It is shown that most of the radiation of the diamond samples in the region of 240–750 nm under the action of an electron beam with electron energy of up to 200 keV belongs to cathodoluminescence.
Об эффекте Гуса-Хенхена при наличии возбуждения поверхностных волн в схеме Кречмана
Authors: Петрин А.Б.
Published: September 2019

AbstractA theoretical method for investigating reflection of a finite-aperture plane light beam from a flat-layered structure in the Kretschmann scheme is considered. The developed theory is applied for investigating the Goos–Hänchen effect, which arises upon incidence of a linearly polarized light beam with the polarization vector lying in the plane of incidence ( p -polarized beam) and which is that, upon reflection, the incident beam is divided into two close beams of the same polarization. The accuracy of sensors based on this effect is discussed.
Особенности взаимодействия в водных растворах молекул поливинилпирролидона с ионами цинка и серебра по данным ИК спектроскопии
Authors: Волкова Н.А. , Евстропьев С.К. , Никоноров Н.В. , Евстропьев К.С.
Published: September 2019

AbstractAqueous solutions containing polyvinylpyrrolidone and zinc and silver nitrates are studied by IR spectroscopy. It is shown that introduction of zinc and silver nitrates into polyvinylpyrrolidone solutions leads to a shift of the polymer absorption bands to lower wavenumbers. The results obtained indicate the possibility of formation of complexes consisting of polymer molecules and metal ions.
Изучение влияния легирования никелем кремниевых солнечных элементов с глубоким p-n-переходом
Authors: Бахадырханов М.К. , Исамов С.Б. , Кенжаев З.Т. , Ковешников С.В.
Published: September 2019

It is shown that doping front side of solar cell with deep-lying p-n junction with nickel atoms leads to significant increase in Jsc – 89 % and Voc - 19.7 %. Additional heat treatment at 700 ° C for one hour leads to an increase in Jsc – 98,4 % and Voc - 13,18 %. Growth in efficiency of conversion of infrared radiation is occurs due to formation of clusters of nickel atoms, which are getter centers for uncontrolled recombination impurities.
Palliative Radiation Therapy in patients with Oncology urological diseases: a component of complex treatment of Metastatic Bone Lesions
Authors: Dzhabarov F. R. , Alnikin A. B.
Published: September 2019

Background. Patients with first diagnosed prostate cancer, kidney cancer and bladder cancer, more than 25% of cases are diagnosed at stage IV disease at the primary visit in clinics. A characteristic feature of these types of tumors is a predisposition to bone metastasis. Bones failure at the treatment stages is diagnosed in 80% of patients already.

Objectives. Determine the most effective palliative analgesic radiotherapy regimens.

Materials and methods. Case histories of 41 patients with a diagnosis of osteolytic bone lesion were analyzed. The male / female ratio is 32/9. All patients underwent radiotherapy in the Radiological Division of the Rostov District Oncological Dispensary for the period from 2015 to 2018

Results. The direct effectiveness of the analgesic effect of large-fraction radiotherapy is slightly higher than that of single-fraction radiotherapy. However, the opposite trend was observed a month after the R-therapy end. It was determined that higher analgesic effect corresponds to higher values of a single focal dose (SFD).

Conclusion. This method deserves closer attention despite the low direct efficiency of single-fraction radiation. This is due to the high and persistent analgesic activity and the short duration of the course
Pyelonephritis in pregnant women: where to start?
Authors: Shkodkin S. V.
Published: September 2019

Pyelonephritis in pregnant women is an urgent problem for urology. In the Russian clinical guidelines, there are disagreements on the classification of pyelonephritis. This is probably the cause of its overdiagnosis in pregnant women, as evidenced by the increase in the statistical frequency of pregnant pyelonephritis. This situation is the reason for the unjustified etiotropic therapy of pyelonephritis in this category of patients. On the other hand, the diagnosis of chronic pyelonephritis can cause an underestimation of the severity of the patient’s condition and increase the risk of an adverse outcome of the disease. Along with this, the literature has accumulated data on the absence of a morphological substrate of inflammation during periods of so-called remission, and that pyelonephritis should be considered as reinfection. All this call into question the eligibility of the term chronic in relation to pyelonephritis. In the available literature there are few data on the physiology of the urinary tract in pregnant women. Nevertheless, the accumulated experience indicates the safety of excretory function despite dilatation of the upper urinary tract. In addition, there are no studies indicating the benefits of drainage of both asymptomatic and symptomatic hydronephrosis in pregnancy. All this does not allow associating pregnant pyelonephritis with obstructive in non-pregnant patients, and asymptomatic dilatation of the upper urinary tract should be interpreted as a physiological state.
The anatomy of the renal lower calyceal group influence on the risk of residual stones in the Urolithiasis treatment
Authors: Guliev В. G. , Cheremisin V. M. , Talyshinsky A. Е.
Published: September 2019

Background. There are various data in the literature regarding the boundary values of the width and length of the neck, as well as the angle between the pelvis and infundibulum. These parameters distinguish between patients with high and low risk of residual fragments.

Objectives. The purpose of this study is to examine the lower calyceal group anatomy of patients without kidney stones and to compare the obtained results with previously published one. Materials and methods. Retrospective stage: Computed tomography (CT) scan of the abdomen was obtained in 120 patients (which was performed on them from March 2018 to 2019). CT scans of 100 patients (200 kidneys) were included in analysis after exclusion of inappropriate data. The infundibulopelvic angle was measured using the two most common methods by Sampaio and by Elbahnasy. Also, the length and width of the lower infundibulum were measured. All results were divided into four groups depending on the Sampaio classification of pyelocaliceal system (PCS). Results. The average value of the infundibulopelvic angle according to the Elbahnasy’s method is 74.1±15.1, and according to the Sampaio method is 101.8±20.1. When measured by the Elbahnasy method, an angle of more than 90 ° is more likely to occur with A1 structure variant, and less than 90 ° is more likely to occur in the PCS corresponding to the A2 variant. The average length of the lower infundibulum is 20.7±2.8 mm. The higher value of the lower infundibulum width was in group A1. Conclusion. In our study, all parameters were out of risk of both the low success of the operation and the development of kidney stone indicated in previously published studies. This fact can confirm the influence of the anatomy of the lower calyceal group on the development of kidney stones.
Estimation of the balance of metabolizable lysine and methionine for dairy cows
Authors: Olivera-Angel Martha , Duque-Quintero Mónica , Rosero-Noguera Ricardo
Published: September 2019

Objective.The aim of this study was to determine in grazing cows,the reproducibility and accuracy of the balance between predicted values,when compared with theobserved valuesfor the most limiting amino acids in milk protein synthesis, the methionine (Met)andLysine (Lys).Materials and methods.Twelve lactatingcows were used for a 20-día experimental period. Control: animals grazing and supplemented with balanced food; Met-Lys: same as control and supplemented with adjusted rumen protected Met and Lys.For Met and Lys supply predicted values, it was taking in account the average of the dry matter intake (DMI) of the herd, based in offer and foraging control and values of microbial protein data. Observed values were determined based in the individual DMI intake, using external and internal markers and the individual microbial protein production. A t-paired-sample test was performed and the efficiency of the model’s prediction was determined using the mean square prediction error (MSPE) and the concordance coefficient (CCC). Results. Significant differences were found between the predicted and observed values for DMI forage, digestible microbial protein and microbial protein production, supply and the balance of Lys and Met. The CCC for Lys and Met balance were low (0.10), the MSPE was high except for the total DMI with a moderate concordance (0.63) and low MSPE (4.42). Conclusions. These results indicate a lack of precision of the tools, which underestimates the supply and balance of amino acids in individual grazing cows.
Estimating the Impact of Novel Digital Therapeutics in Type 2 Diabetes and Hypertension: Health Economic Analysis
Authors: Nordyke Robert J , Appelbaum Kevin , Berman Mark A
Published: September 2019

Background

Behavioral interventions can meaningfully improve cardiometabolic conditions. Digital therapeutics (DTxs) delivering these interventions may provide benefits comparable to pharmacologic therapies, displacing medications for some patients.

Objective

Our objective was to estimate the economic impact of a digital behavioral intervention in type 2 diabetes mellitus (T2DM) and hypertension (HTN) and estimate the impact of clinical inertia on deprescribing medications.

Methods

Decision analytic models estimated health resource savings and cost effectiveness from a US commercial payer perspective. A 3-year time horizon was most relevant to the intervention and payer. Effectiveness of the DTx in improving clinical outcomes was based on cohort studies and published literature. Health resource utilization (HRU), health state utilities, and costs were drawn from the literature with costs adjusted to 2018 dollars. Future costs and quality-adjusted life years (QALYs) were discounted at 3%. Sensitivity analyses assessed uncertainty.

Results

Average HRU savings ranged from $97 to $145 per patient per month, with higher potential benefits in T2DM. Cost-effectiveness acceptability analyses using a willingness-to-pay of $50,000/QALY indicated that the intervention would be cost effective at total 3-year program costs of $6468 and $6620 for T2DM and HTN, respectively. Sensitivity analyses showed that reduced medication costs are a primary driver of potential HRU savings, and the results were robust within values tested. A resistance to deprescribe medications when a patient’s clinical outcomes improve can substantially reduce the estimated economic benefits. Our models rely on estimates of clinical effectiveness drawn from limited cohort studies with DTxs and cannot account for other disease management programs that may be implemented. Performance of DTxs in real-world settings is required to further validate their economic benefits.

Conclusions

The DTxs studied may provide substantial cost savings, in part by reducing the use of conventional medications. Clinical inertia may limit the full cost savings of DTxs.
Development and Assessment of a Gastroscopy Electronic Learning System for Primary Learners: Randomized Controlled Trial (Preprint)
Authors: Li Shuang , Li Guoqing , Liu Ying , Xu Wanying , Yang Ningning , Chen Haoyuan , Li Ning , Luo Kunpeng , Jin Shizhu
Published: September 2019

BACKGROUND

Endoscopic examination is a popular and routine procedure for the diagnosis and treatment of gastrointestinal (GI) diseases. Skilled endoscopists are in great demand in clinical practice, but the training process for beginners to become endoscopy specialists is fairly long. Convenience and a self-paced, learner-centered approach make electronic learning (e-learning) an excellent instructional prospect.

OBJECTIVE

This study aimed to develop and apply an e-learning system in gastroscopy teaching and learning and to evaluate its effectiveness and user satisfaction.

METHODS

The e-learning software Gastroscope Roaming System was developed for primary learners. The system simulates the real structure of the upper gastrointestinal (UGI) tract to teach the main characteristics of gastroscopy under both normal conditions and conditions of common UGI tract diseases. A randomized controlled trial was conducted. Participants were randomly allocated to an e-learning group (EG)or a non–e-learning control group after a pretest. On completing the training, participants undertook a posttest and gastroscopy examination. In addition, the EG completed a satisfaction questionnaire.

RESULTS

Of the 44 volunteers, 41 (93%) completed the gastroscopy learning and testing components. No significant pretest differences were found between the intervention and control groups (mean 50.86, SD 6.12 vs mean 50.76, SD 6.88; P=.96). After 1 month of learning, the EG’s posttest scores were higher (mean 83.70, SD 5.99 vs mean 78.76, SD 7.58; P=.03) and improved more (P=.01) than those of the control group, with better performance in the gastroscopy examination (mean 91.05, SD 4.58 vs mean 84.38, SD 5.19; P<.001). Overall, 85% (17/20) of the participants were satisfied with the e-learning system, and 95% (19/20) of the participants considered it successful.

CONCLUSIONS

E-learning is an effective educational strategy for primary learners to acquire skills in gastroscopy examination and endoscopic imaging of the GI tract.

CLINICALTRIAL

Chinese Clinical Trial Registry ChiCTR-IOR-17013091; http://www.chictr.org.cn/showproj.aspx?proj=22142
Using the Self-Management Assessment Scale for Screening Support Needs in Type 2 Diabetes: Qualitative Study (Preprint)
Authors: Öberg Ulrika , Orre Carl Johan , Hörnsten Åsa , Jutterström Lena , Isaksson Ulf
Published: September 2019

BACKGROUND

Globally, most countries face a common challenge by moving toward a population-based structure with an increasing number of older people living with chronic conditions such as type 2 diabetes. This creates a considerable burden on health care services. The use of digital tools to tackle health care challenges established views on traditional nursing, based on face-to-face meetings. Self-management is considered a key component of chronic care and can be defined as management of the day-to-day impact of a condition, something that is often a lifelong task. The use of a screening instrument, such as the Self-Management Assessment Scale (SMASc), offers the potential to guide primary health care nurses into person-centered self-management support, which in turn can help people strengthen their empowerment and self-management capabilities. However, research on self-management screening instruments is sparse, and no research on nurses’ experiences using a digitalized scale for measuring patients’ needs for self-management support in primary health care settings has been found.

OBJECTIVE

This paper describes diabetes specialist nurses’ (DSNs) experiences of a pilot implementation of the SMASc instrument as the basis for person-centered digital self-management support.

METHODS

This qualitative study is based on observations and interviews analyzed using qualitative content analysis.

RESULTS

From the perspectives of DSNs, the SMASc instrument offers insights that contribute to strengthened self-management support for people with type 2 diabetes by providing a new way of thinking and acting on the patient’s term. Furthermore, the SMASc was seen as a screening instrument with good potential that embraces more than medical issues; it contributed to strengthening person-centered self-management support, and the instrument was considered to lead both parts, that is, DSNs and patients, to develop together through collaboration.

CONCLUSIONS

Person-centered care is advocated as a model for good clinical practice; however, this is not always complied with. Screening instruments, such as the SMASc, may empower both nurses and patients with type 2 diabetes with more personalized care. Using a screening instrument in a patient meeting may also contribute to a role change in the work and practice of DSNs.
Voices in Evidence-Based Newborn Care: A How-to-Guide on Developing a Parent-Facing Podcast (Preprint)
Authors: Parga-Belinkie Joanna , Merchant Raina M
Published: September 2019

UNSTRUCTURED

Podcasting is becoming a more popular form of media. Its use in medical education is being researched—but what about its use in public education? In this tutorial, the authors offer a how-to-guide on starting a public or patient-facing podcast. The authors hope to inspire more physicians to utilize this type of media to share evidence-based information. More research is needed looking into how podcasting can be used to help with patient education.
Preliminary evidence-based recommendations for return to learn: a novel pilot study tracking concussed college students
Authors: Bevilacqua Zachary W , Kerby Mary E , Fletcher David , Chen Zhongxue , Merritt Becca , Huibregtse Megan E , Kawata Keisuke
Published: September 2019

Aim: Students re-entering the academic setting after a concussion is commonly referred to as return-to-learn and, to date, very few studies have examined the return-to-learn aspect of concussion recovery. Methodology: Nine college-aged, full-time students who were diagnosed with concussions were monitored throughout their concussion recovery. The severity for five chief symptoms (headache, dizziness, difficulty concentrating, fatigue, anxiety) were recorded six-times per day through text messages, and daily phone calls recorded participant's behavioral traits. Results: We identified five behavioral variables which significantly influenced symptom resolution (music, sleep, physical activity, water and time) (p = 0.0004 to p = 0.036). Additionally, subjects reported math and computer-oriented courses as the most difficult (33 and 44%, respectively). Conclusion: We introduce a novel approach to monitor concussed students throughout their recovery, as well as factors that may influence concussion recovery process.