bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Testing of BaZrGe-=SUB=-3-=/SUB=-O-=SUB=-9-=/SUB=- : Mn-=SUP=-4+-=/SUP=- for Application as a Red-Emitting Phosphor
Authors: Wang X.  , Zhai M.  , Ivanovskikh K. V.  , Guo H.  , Huang P.  , Cui C.  , Wang L.  , Shi Q.
Published: January 2023

A series of novel red-emitting phosphors BaZrGe3O9 : Mn4+ (BZG : Mn4+) were synthesized through high-temperature solid-state reaction method in order to explore their capabilities for application as red-emitting phosphors. The phosphors were characterized by X-ray diffraction, photoluminescence spectra, and decay curve measurements at the temperature ranging from 80 to 500 K. The luminescence intensity increases to maximum at doping concentration of 0.2 mol.%, and then decreases with concentration. Serious thermal quenching was also revealed. Keywords: red-emitting phosphor, germanate, Mn4+, concentration quenching, thermal stability.
Increasing the intensity of the glow of the phosphor Gd-=SUB=-2-=/SUB=-O-=SUB=-2-=/SUB=-S : Tb(3-7 mol.%), caused by a change in the distribution of the Tb-=SUP=-3+-=/SUP=- activator over the real crystal lattice
Authors: Bakovets V.V.  , Sokolov V.V.  , Dolgovesova I.P.  , Pivovarova T.D.  , Filatova I.J.  , Rakhmanova M.I.  , Jushina I.V.  , Asanov I.P.  , Sotnikov I.V.
Published: January 2023

Luminophores Gd2O2S : Tb(3-7 mol.%), obtained through the stage of sol-gel formation of Gd2O3 : Tb precursors with their subsequent sulfidation in sulfur vapor with LiF flux at 700oC, showed high luminescence efficiency. The characterization of the obtained samples by a set of physicochemical methods established that an increase in the concentration of the Tb3+ activator leads to its specific distribution: over gadolinium vacancies (VGd)''', by replacing Gd3+ ions and concentrating it at the boundaries of crystallites. It is noted that in this case, the morphology of crystallites changes, the short-range order of the structural unit of the lattice (Gd2O2) changes with the introduction of S2- ions into oxygen vacancies [VO]oo or the substitution of O2- anions, as a result of which the long-range order of the anionic sublattice is violated and the band gap decreases. At high concentrations of the photoluminescence activator Tb3+ 7 mol.%, radiation quenching does not occur due to the presence of the GdOF and TbOF phases. Variations of these effects with an increase in the Tb3+ concentration lead to an increase in the intensity of the emission in the green region of the 5D4->7Fj transitions and a decrease in the intensity of the emission in the blue region of the 5D3->7Fj transitions. Keywords: phosphor Gd2O2S : Tb(3-7 mol.%), real lattice structure, photoluminescence activator distribution, far infrared spectroscopy, Raman spectroscopy, XPS spectroscopy.
Boron-doped silicon: a possible way of testing and refining models of non-ionizing energy loss under electron- and proton irradiation
Authors: Emtsev V. V.  , Abrosimov N. V.  , Kozlovski V. V.  , Lastovskii S. B.  , Oganesyan G .A  , Poloskin D. S.  , Aref'ev A. A.
Published: January 2023

In this paper formation and annealing of boron-related defects in p-type silicon grown by the floating zone technique and subjected to electron and proton irradiation at room temperature are discussed. The defect model suggested earlier has provided fresh insight into the nature of two dominant complexes containing boron in irradiated p-Si, among them boron-divacancy complexes and interstitial boron-substitutional boron pairs. In the present work the same material is irradiated with 6 MeV electron and 8 MeV protons providing additional electrical data to test this model. Additionally new information on boron-related defects in heavily doped p-Si subjected to irradiation with 2.5 MeV electrons at 4.2 K and then subjected to isochronal anneals above room temperature is also discussed. The results obtained on proton irradiated p-Si(FZ) testify that the annealing behavior of boron-divacancy complexes appears to be complicated, in contrast to the behavior of substitutional boron-interstitial boron pairs. The defect model based on the experimental information furnished so far may be used for testing and refining computerized simulations of Non-Ionizing Energy Loss (NIEL) in irradiated silicon. Keywords: silicon, boron impurity, electron- and proton-irradiation, impurity-related complexes.
Dynamics of magnetization of a uniaxial nanoparticle in the region of noncollinear ferromagnetic resonance
Authors: Shutyi A. M.  , Sementsov D. I.
Published: January 2023

Resonance dynamics of the magnetic moment of a uniaxial ellipsoidal nanoparticle under its magnetic biasing along the symmetry axis and excitation by a transverse high-frequency field is studied with the parameters (frequency, magnetic bias field and shape parameter), corresponding to the noncollinear orientation of equilibrium magnetization and the external static field. We revealed the frequency regions where precession becomes nonlinear at a weak alternating field and dynamic bistability, as well as complex spatial attractors and chaos are implemented. Keywords: ellipsoidal nanoparticle, ferromagnetic resonance, static and high-frequency field, nonlinearity, effective anisotropy, bistability, regular and chaotic precession.
Transition from solid-solution softening to hardening in the plasticity of crystalline materials as a manifestation of quasi-localization of dislocation kinks
Authors: Petukhov B.V.
Published: January 2023

The mechanical properties of materials are highly sensitive to the content of impurities and point defects due to their interaction with plastic deformation carriers-dislocations. This opens up the possibility to some extent control the mechanical properties of materials through alloying and creating solid solutions. In a number of crystalline materials, in addition to the well-known solid-solution strengthening in the region of a low concentration of solution atoms, the opposite behavior is also observed --- an increase of plasticity, or softening. In the present work, the mechanism of competition of these effects is revealed and it is shown how the boundary of behavior change can be used to estimate the microscopic parameters of materials. The theory predicts trends in the dependence of plasticity on the concentration of alloying elements, stress, temperature, strain rate, and a number of material parameters. Keywords: competition of solid-solution hardening and softening, dislocation kinks, random processes.
Tetragonal nanocrystalline phases in oxides Re-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-
Authors: Shmytko I. M.  , Kedrov V. V.
Published: January 2023

X-ray diffractometric studies of the structural state of simple rare-earth oxides Gd2O3, Sm2O3 and Eu2O3 were carried out, synthesized by different methods, at the first stages of crystal formation. It was found that the first crystalline phase of these compounds in the nanocrystalline state is not a known cubic modification with the spatial symmetry group S.G. Ia-3 (206), but tetragonal phases, whose spatial groups are not established due to the small number of strong reflexes in the nanostate. It is also shown that the same tetragonal phases are formed in industrial powders of these compounds subjected to long-term storage. Keywords: synthesis of Re2O3, glycine-nitrate method, nanocrystalline state, X-ray diffraction research methods, phase transitions.
Features of polarization of piezoelectric ceramics based on sodium niobate
Authors: Malyshkina O.V.  , Ali M.  , Ivanova A.I.  , Chernyshova I.A.  , Mamaev D.V.
Published: January 2023

Comparative studies of the pyroelectric properties and structural features of sodium niobate and sodium-potassium niobate ceramics obtained under different technological conditions for the synthesis of sodium niobate have been carried out. X-ray phase analysis revealed the existence of an additional phase with the chemical formula NaNb10O18 in sodium niobate ceramic samples that do not exhibit ferroelectric properties. It is shown that the temperature conditions for the synthesis of the sodium niobate material determine the nature of the macroscopic polarization of the samples of both pure sodium niobate and sodium-potassium niobate. Keywords: piezoelectric ceramics, lead-free materials, polarization, pyroelectric effect.
First-order phase transition in nanotubular titanium dioxide
Authors: Sushnikova A.A.  , Valeeva A. A.  , Dorosheva I.B.  , Rempel A.A.
Published: January 2023

Titanium dioxide (TiO2) nanotubes array with the length of 16 μm and the outer diameter of 100 nm were synthesized by anodic oxidation of titanium foil in an electrolyte solution containing a fluorine-containing solution of ethylene glycol. The selected synthesis conditions make it possible to separate the nanotubular array from the titanium foil and study it as a homogeneous functional material. The performed scanning electron microscopy study and Brunauer--Emmett--Teller analysis allowed to get data on the morphology of the samples. X-ray diffraction, thermogravimetric, and differential scanning calorimetry analysis made it possible to determine the temperature of the phase transition of the amorphous state into crystalline anatase (sp.gr. I4/amd). Observed phase transition of first order takes place at temperature about 350oC. Keywords: nanotubular titanium dioxide films, anodic oxidation, phase transition, anatase, TG, DSC.
The role of diffusion of photoexcited electrons from heavily doped layers in the photoconductivity of AlAs/GaAs heterostructures
Authors: Vdovin E. E.  , Khanin Yu. N.
Published: January 2023

Based on the study of photoconductivity in GaAs / AlAs p-i-n heterostructures in the visible light range, the dominant role of the diffusion channel of photoexcited electrons from heavily doped layers in the formation of photocurrent oscillations from the bias voltage and the determining contribution of this channel to the total current through the structure is shown. A qualitative model of the transport of excited carriers is considered, which assumes the diffusion channel as the main source of photooscillations. Keywords: heterostructures, photoconductivity.
Controllable formation of TiO2-rutile nanostructures with a specified morphology using thermal oxidation technique
Authors: Khubezhov S. A.  , Ponkratova E. Yu.  , Karsakova M. E.  , Prigodich V. V.  , Il’in O. I.  , Silaev I. V.  , Tvauri I. V.  , Yakimchuk D. V.  , Kaniukov E. Yu.  , Zuev D. A.
Published: January 2023

Titanium dioxide nanostructures are formed by a simple one-stage method of thermal oxidation of titanium in the temperature range of 700-900oC. The structures were studied by high-resolution electron microscopy and X-ray diffraction. It is shown that, depending on the temperature, nanostructures in the form of crystallites, granules, and dendrites of TiO2-rutile are formed on the surface of metallic titanium. The proposed method is promising for the large-scale creation of advanced functionalized TiO2 surfaces applicable in catalysis and sensorics. Keywords: nanostructures, titanium dioxide, thermal oxidation, morphology, dendrites.
Viscoelastic properties of nanofluids with carbon tubes
Authors: Rudyak V. Ya.  , Dashpilov G. R.  , Minakov A. V.  , Pryazhnikov M. I.
Published: January 2023

The method of diffusion wave spectroscopy is used to study the microrheology of several nanofluids based on water, ethylene glycol and isopropyl alcohol with single-wall and multi-wall nanotubes. Their viscosity and rheology have been previously investigated, and it has been shown that, starting with a certain concentration of carbon nanotubes, nanofluids are non-Newtonian and viscoplastic. At the same time, it was experimentally established that these nanofluids are viscoelastic. Various viscoelastic characteristics of these nanofluids have been systematically studied and compared. Keywords: viscoelasticity, nanofluid, microrheology, carbon nanotubes.
Studying LiFePO-=SUB=-4-=/SUB=- powder samples via X-ray diffraction techniques using artificial neural networks
Authors: Boiko M. E.  , Sharkov M. D.  , Boiko A. M.  , Bobyl A. V.  , Nikolaev V. I.
Published: January 2023

A set of LiFePO4 samples has been studied by small-angle X-ray scattering (SAXS). Using the technique of artificial neural networks, the shape of SAXS curves has been reconstructed taking into account the hardware function. Estimates of homogeneitiessizes and shapes in the studied LiFePO4 samples have been obtained. Keywords: Small-angle X-ray scattering, artificial neural network, lithium-ion rechargeable batteries, incorrect tasks regularization.
Gas-sensing properties of In-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=--Ga-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- alloy films
Authors: Nikolaev V. I.  , Almaev A. V.  , Kushnarev B. O.  , Pechnikov A. I.  , Stepanov S. I.  , Chikiryaka A. V.  , Timashov R. B.  , Scheglov M. P.  , Butenko P. N.  , Chernikov E. V.
Published: January 2023

The effect of the gaseous medium composition on the electrically conductive properties of In2O3-Ga2O3 films obtained by halide vapor phase epitaxy has been studied. In the temperature range of 100-550oC, the In2O3-Ga2O3 films exhibit high sensitivity to H2, NH3 and possess hyphen performance and low base resistance. A qualitative mechanism for the sensitivity of In2O3-Ga2O3 films to gases is proposed. Keywords: In2O3-Ga2O3, halide vapor-phase epitaxy, gas sensitivity.
Effect of low temperature nitrogen plasma composition on hydrophilic and hydrophobic properties of coatings nitrided titanium oxide based
Authors: Muslimov A.E.  , Gadzhiev M. Kh.  , Emirov R. M.  , Ismailov A.M.  , Kanevsky V.M.
Published: January 2023

Effect of nitrogen plasma composition on structural-phase and elemental composition, topography, mechanical and hydrophobic properties of coatings on the basis of nitrogen-containing titanium oxide during penetration onto sample in open atmosphere is studied. It has been shown that at an equally high microhardness of the order of 25--27 GPa, by controlling the composition of the nitrogen plasma, either hydrophilic (contact angle 73o)) or hydrophobic coatings (contact angle 120o)) can be formed. Keywords: hydrophobicity, hydrophilicity, titanium dioxide, sapphire, low-temperature plasma, nitrogen, contact angle, microhardness.
Investigation of the conditions for gas breakdown in a porous dielectric
Authors: Medvedev D.D.  , Belov N.K.  , Grankina O.O.  , Knizhnik A.A.  , Korobtsev S.V.  , Potapkin B.V.
Published: January 2023

Plasma treatment of porous polymeric materials is a promising method for creating new materials that can be used in various applied problems, including medicine, in the development of new types of biocompatible and biodegradable polymeric materials. This work is devoted to the study of the processes of plasma treatment of porous polymeric materials depending on the size and type of pores in order to clarify the breakdown conditions and optimize the treatment process. A convenient semi-empirical model of the development of breakdown in a porous dielectric is proposed. Keywords: plasma treatment of a dielectric, Paschen's law in a porous medium, breakdown voltage of a porous material.
Modeling of the interstellar medium Optical absorption spectrum by primitive hybrid molecules C-=SUB=-24-=/SUB=-H-=SUB=-30-=/SUB=-, C-=SUB=-32-=/SUB=-H-=SUB=-36-=/SUB=- and C-=SUB=-73-=/SUB=-H-=SUB=-74-=/SUB=-
Authors: Chekulaev M. S.  , Yastrebov S. G.
Published: January 2023

Accounting for the different contributions of the aromatic rings, separated with sp3 bonds, with ab initio method we constructed the hybrid cluster C73H74 which UV spectrum matches the most noticeable absorption band of 217.5 nm, known from astrophysical observations Keywords: interaction of light with matter, new forms of carbon, interstellar medium.
Influence of the crystal substrate parameters on the maximum power of silicon heterojunction solar cells
Authors: Panaiotti I. E.
Published: January 2023

The effect of the donor impurity concentration and the lifetime of charge carriers in a crystalline silicon substrate on the maximum power of heterojunction thin-film solar cells is studied. The model used in the calculations takes into account the features of photocurrent generation under conditions of medium or high levels of injection of charge carriers at an arbitrary ratio between the diffusion length and the thickness of the semiconductor wafer. The proposed technique makes it possible, with sufficient accuracy for practical purposes, to calculate the permissible variation limits of the substrate parameters, which ensure the specified values of the performance characteristics of photoelectric converters. Keywords: heterojunction solar cells, crystalline silicon substrates, optimal parameters, maximum power.
Focused ion beam milling of ridge waveguides of edge-emitting semiconductor lasers
Authors: Payusov A. S.  , Mitrofanov M. I.  , Kornyshov G. O.  , Serin A. A.  , Voznyuk G. V.  , Kulagina M. M.  , Evtikhiev V.P.  , Gordeev N.Yu.  , Maximov M. V.  , Breuer S.
Published: January 2023

We studied the influence of the focused ion beam milling of ridge waveguides on lasing parameters of edge-emitting lasers, based on a separate confinement double heterostructure. It is shown that there are three degrees of influence, according to the etching depth: modification of the waveguide properties only, a decrease in efficiency without changing the threshold current, and a simultaneous deterioration in the threshold current and efficiency with significant modification of the optical characteristics of the laser. Keywords: focused ion beam, semiconductor laser, optical waveguide, single mode lasing.
Effective Health Screening Strategies for Overcoming Non-Communicable Diseases in Sambimulyo Village, Banyuwangi Regency
Authors: Az Zahra Tazkia Izzatun , Hambin Era Samudra , Novirianingtyas Tsabitah Virza , Wicaksono Tri Yoga , Wahyuliana Lailia , Wardhani Aulia Seftya , Latifa Kayla Juwita Qalbu , Amrullah Rafi , Wati Putri Fatimahtuz Zahra Puji Anggar , Mandagi Ayik Mirayanti
Published: January 2023

Non-communicable diseases (NCDs) are chronic conditions that cannot be transmitted from one person to another. These conditions do not usually cause symptoms at first, but over time they can progress and damage the affected organ, leading to complications or even death. A lack of public knowledge about NCDs is a major contributor to complications and deaths from these diseases. To address this issue, a series of activities have been organized as part of the Movement for the Control of Non-Communicable Diseases. These activities focus on understanding the definitions, risk factors, prevention methods, and symptoms of diabetes, hypertension, and hyperuricemia. This study used a descriptive observational method, collecting primary data from pre- and post-test responses and health test results. In the first intervention, information about NCDs was provided and participants’ knowledge was increased by 31.25%. The second intervention was a health screening, which included measuring blood pressure and blood sugar levels. Uric acid levels were also measured at five points in Sambimulyo Village, with 129 participants. The results showed that 41.1% had high blood pressure, 29.5% were classified as diabetic, and 18.8% had high uric acid levels. These activities increased public knowledge about NCDs, provided information about the community’s risk factors, and improved communication, education, and information about how to manage these conditions.
Dielectric Behaviour of Metal Complexes Cu (II), Ni (II) and UO2 ((VI) Of the Ligand Oxaloanilic Acid Hydrazone
Authors: Pattar Raveendra T.
Published: January 2023

Abstract: The dielectric behaviour and molecular structure of metal complexes Cu(II),Ni(II) and UO2((VI) of the ligand oxaloanilic acid hydrazine have been investigated using Time Domain Reflectometry (TDR) technique in the frequency range 10 MHz to 10GHz. Cole-Davidson model has been applied for fitting the complex permittivity spectra [ ε* (ω)]. The parameters εs –the static permittivity, τ- the dielectric relaxation time are evaluated at different temperatures from 2880K to 3330K and are discussed in respect of their molecular structural behaviours. The thermodynamic parameters, such as ΔH* - molar enthalpy, ΔS* - the molar entropy are obtained using Eyring.s rate equation. In the light of such data the possible structures of the present complexes are discussed.
Train Collision Avoiding System
Authors: Nagasai S. , Shoheb Md. , Rao B. Shashidhar , Sreenivasulu Dr. Y. , Krishna Dr.
Published: January 2023

Abstract: The main end of the design is to measure the speed of trains and to insinuate it to the station control room TCAS, if the train exceeds it’s maximum speed limit. Then we will place two IR transmitter receiver dyads with some distance, along the road. And by calculating the time difference between the activation of two IR receivers as per the law sense, the speed of the train can be calculated. So now we will design the design in such a way that the regulator will be connived to the two IR receivers and to the GSM modem through a line motorist IC MAX232 for periodical communication. Then GSM modem is used to shoot the SMS to the control room to insinuate about the overspeeds.However, the GSM modem sends corresponding data to the station control room TCAS as per the law sense, If any train crosses the speed limit means the time between the activation of two IR detectors is lower than the time limit
Development of nominal rules on the Fuzzy Sugeno method to determine the quality of power transformer insulation oil using Dissolved Gas Analysis data
Authors: Ha'imza Ha'imza , Amirullah Amirullah , Plangklang Boonyang
Published: January 2023

This paper aims to develop the nominal rules on the Fuzzy Logic Method using the Sugeno-Fuzzy Inference System (FIS) for Dissolved Gas Analysis (DGA) and determine the quality of the power Transformer 1 and Transformer 6 insulating oil at the Buduran 150 kV substation. The nominal number of proposed fuzzy rules is 1920 rules. Implementing the Fuzzy-Sugeno method on Transformers 1 and 6 shows that the six input variables from the DGA test can produce a Total Dissolved Combustible Gas (TDCG) output value of 32.67 and 26.19 ppm, respectively. Both values indicate that the insulating oil of Transformers 1 and 6 are in condition one and, at the same time, indicates that the dissolved gas composition is in Normal status. Furthermore, the TDCG value, condition, and quality status of the insulating oil have the same or 100 % accuracy compared to the DGA test by PLN (UPT Surabaya). Thus, the nominal development of fuzzy rules using the Fuzzy-Sugeno method can perform DGA analysis more accurately to determine the quality of power transformer insulation oil compared to previous studies.
La corriente pedagógica social y sus propuestas críticas latinoamericanas en la formación profesional en Trabajo Social, Sede de Occidente, Universidad de Costa Rica
Authors: Quesada Monge Ana Cristina
Published: January 2023

Toda propuesta formativa y profesional universitaria debe ir acompañada de una debida fundamentación curricular y pedagógica. Por eso, este ensayo expone un ejercicio de análisis comparativo que se realizó entre los orígenes y el Plan de Desarrollo Académico de la Carrera de Trabajo Social en la Universidad de Costa Rica, Sede de Occidente, durante los años 2018 al 2021, con una corriente pedagógica específica y varias de sus propuestas particulares. Se elaboró este ensayo con el fin de demostrar que este proceso de análisis es útil para actores del contexto universitario que deben realizar este ejercicio, principalmente en los procesos de autoevaluación de ofertas académicas en la educación superior. A través de este análisis comparativo, se concluye que en los inicios de la carrera de Trabajo Social, en la Sede de Occidente, tuvo una influencia de la corriente pedagógica social, principalmente de corte socialista o marxista; no obstante, algunos planteamientos expuestos en el Plan de Desarrollo Académico de los años 2018 al 2021, se logra identificar la incorporación de otras propuestas pedagógicas críticas, tales como educación popular, pedagogías de Paulo Freire, territorizada y alteridad. Las dos últimas son consideradas como pedagogías críticas latinoamericanas. A su vez, se encontró una serie de elementos de las condiciones organizativas institucionales que limitan la aplicación y el alcance de estas pedagogías en la formación profesional de trabajadores sociales en la Sede de Occidente, Universidad de Costa Rica.
Por medio de un análisis comparativo, se concluye que en los inicios de la Carrera de Trabajo Social en la Sede de Occidente, se tuvo una influencia de la corriente pedagógica social, principalmente de corte socialista o marxista; no obstante, en algunos planteamientos expuestos en el Plan de Desarrollo Académico de los años 2018 al 2021, se logra identificar la incorporación de otras propuestas pedagógicas críticas latinoamericanos, tales como: la Educación Popular y las pedagogías críticas de Paulo Freire. Además, también se identifica los aportes de las pedagogías criticas latinoamericanas “territorizadas y alteridad”, clasificadas de esta manera por Cabaluz-Ducasse (2016). A su vez, se logra identificar una serie de elementos de las condiciones organizativas institucionales que limitan la aplicación y el alcance de estas pedagogías críticas en la formación profesional de trabajadores sociales en la Sede de Occidente, Universidad de Costa Rica.
Una visión del paradigma de la educación en la dualidad de la gestión de la educación como parte del proceso educativo
Authors: Jiménez González Kenneth
Published: January 2023

En el siguiente ensayo se presenta una visión del paradigma de la educación en un proceso evolutivo de cambio, en donde desde los espacios de análisis socioeducativos se desarrolla una reflexión de cómo desde tiempos pasados se siguen líneas de pensamiento que se transforman en el sistema por corrientes tecnológicas y de información, junto a una visión diferente de nuevas estructuras educativas y administrativas. En donde la gestión administrativa en esta evolución parte de los principios racionales de la gerencia, para ir pasando desde los albores de la expansión educativa, hasta los hechos didácticos en esta expansión, junto a las corrientes de pensamiento. Entre la dualidad del cambio, se determina cómo el cambio de paradigma es difícil de erradicar y pervive en la educación que sigue siendo de producción, por ello se mantiene una “modernización” que construye moldes ideales desde los cuales nos medimos, comparamos y se establece el deber ser; mientras el sistema escolar legitima que culpar al docente por las crisis educativas es negar que ellos mismos (el sistema) están alienados en su trabajo. Un proceso de gestión educativa exitoso se debe de visualizar con profundidad, en función no solo de los intereses economistas, sino también del individuo y del desarrollo personal del mismo en procura de personas exitosas en todos los ámbitos personales.
Renal failure after cisplatin-based chemotherapy in the treatment of advanced stage of nasopharyngeal cancer
Authors: Khelil Marwa , Abaza Hajer
Published: January 2023

A 43-year-old male patient who had an advanced stage of nasopharyngeal
carcinoma developed after administration of cisplatin an acute renal
failure until he required hemodialysis and his renal failure was
permanent. The renal biopsy examination indicated partial recovery of
the proximal tubule, but renal function did not recover.
Inference of age-dependent case-fatality ratios for seasonal influenza virus subtypes A(H3N2) and A(H1N1)pdm09 and B lineages using data from the Netherlands
Authors: McDonald Scott , Teirlinck Anne , Hooiveld Mariette , Asten Liselotte , Meijer Adam , Lange Marit de , Gageldonk-Lafeber Arianne van , Wallinga Jacco
Published: January 2023

Background. Despite the known relatively high disease burden of
influenza, data are lacking regarding a critical epidemiological
indicator, the case-fatality ratio. Our objective was to infer age-group
and influenza (sub)type specific values by combining modelled estimates
of symptomatic incidence and influenza-attributable mortality. Methods.
The setting was the Netherlands, 2011/12 through 2019/20 seasons.
Sentinel surveillance data from general practitioners and laboratory
testing were synthesised to supply age-group specific estimates of
incidence of symptomatic infection, and ecological additive modelling
was used to estimated influenza-attributable deaths. These were combined
in an Bayesian inferential framework to estimate case-fatality ratios
for influenza A(H3N2), A(H1N1)pdm09 and influenza B, per 5-year
age-group. Results. Case-fatality estimates were highest for influenza
A(H3N2) followed by influenza B and then A(H1N1)pdm09, and were highest
for the 85+ years age-group, at 4.76% (95% credible interval (CrI):
4.52-5.01%) for A(H3N2), followed by influenza B at 4.08% (95% CrI:
3.77-4.39%) and A(H1N1)pdm09 at 2.51% (95% CrI: 2.09-2.94%). For
55-59 through 85+ years, the case-fatality risk was estimated to double
with every 3.7 years of age. Conclusions. These estimated case-fatality
ratios, per influenza sub(type) and per age-group, constitute valuable
information for public health decision-making, for assessing the
retrospective and prospective value of preventative interventions such
as vaccination, and for health economic evaluations.
Can an alternate biogeomorphological state be triggered by short-term hydrological fluctuations in modified monsoon-driven river systems?
Authors: Geerling Gertjan , Lee CHANJOO , Choi Hun , Kim Donggu , Oorschot Mijke Van , Penning Willemijntje
Published: January 2023

Over the last decade, rapid vegetation colonization and changes in
channel morphology have been observed in the Naeseongcheon Stream in
South Korea, which were linked to short-term hydrological fluctuations
under a changing monsoon climate. The surface area covered by vegetation
has been increasing; this increase intensified after the 2014–2015
drought, which provided a window of opportunity for vegetation
establishment. During the drought, pioneer herbaceous vegetation densely
colonized the lower floodplains, including bare sandbars and temporarily
exposed riverbed. Although the colonized lower floodplain and river
banks were partially rejuvenated by several subsequent floods,
succession to woody vegetation continued, resulting in stable vegetation
cover in areas that had previously been bare. Moreover, sediment carried
by flood water was deposited on and around the vegetated areas, and the
low-water channel was incised, causing vertical development of river
topography. In addition, the main channel width decreased in previously
relatively wide sites, and secondary channels formed. The results of
this study show that river rejuvenation by floods may decrease owing to
systemic changes in the river system. Therefore, we concluded that the
Naeseongcheon watershed was primed by human-induced changes, which made
the river system more susceptible to changes in rainfall and discharge
due to climate change. Furthermore, after the initial vegetation
colonization, changes in nutrients and temperature created a positive
feedback loop, which reinforced vegetation establishment.
“Nirmatrelvir/ritonavir as a posible treatment for Long-COVID ”
Authors: Catalán -Ignacio Pérez , Buj Adriana Gascon , Muñoz -Sergio García , Alfaro -Iris Gómez , Martí -Celia Roig , García -Miguel Torres , Valero -Roberto Reig , Piqueres -Raúl Ferrando , Campos -Lidón Mateu , Ramos Jose-Manuel , Blasco -Jorge Usó
Published: January 2023

It is estimated that about 10% of patients who have been infected with
SARS-CoV-2 worldwide suffer from Long-Covid, about 65 million people
[1]. Although we are beginning to know its pathophysiology, there is
still no evidence on its treatment. We present the case of a patient
with persistent prolonged symptoms who had an optimal response to
nirmatrelvir/ritonavir 2 years after acute infection.
Rapid antigen test with phlegm is more sensitive and detects SARS-CoV-2 earlier than with nasal swab
Authors: Shi Xuanming , Huang Can , He Ning , Chen Bing , Zhang Shengquan
Published: January 2023

Omicron is the current variant of SARS-CoV-2. It has high
transmissibility and evades human immunity. Early and accurate diagnosis
is essential for therapy, prognosis, and curbing the spread of the
virus. Here we reported a new sampling method for the rapid antigen
test, with specimens from phlegm, instead of from nasal swabs.
Sensitivities in detection of SARS-CoV-2 antigen were compared within
the two specimens, and between rapid antigen tests with phlegm specimens
and PCR tests. Of 41 volunteers, thirty-one with positive phlegm
specimens of SARS-CoV-2 eventually had typical COVID-19 symptoms, which
suggested rapid antigen tests with phlegm specimens had 100 % accuracy.
Fourteen of these had antigen tests with nasal swab specimens: 13
negative and 1 positive. Combined with that the antigen levels of the
6561-fold diluted phlegm specimen were comparable to those of the
original nasal swab specimen, antigen tests with phlegm specimens are
more sensitive and earlier detect SARS-CoV-2 than with nasal swab
specimens. Interestingly, case studies indicated antigen tests with
phlegm specimens earlier notified patients of positive infection than
PCR tests. Phlegm specimens enhanced sensitivity in detection of
SARS-CoV-2 in antigen tests, resulting in earlier diagnosis (12 to 42
hours, n=6) than nasal swab specimens. The sensitivity of antigen tests
with phlegm specimens is comparable to that of PCR tests, but the former
earlier outputs test results. Rapid antigen tests with phlegm specimens
facilitate monitoring the health of COVID-19 patients and direct
recovery.
Posterior Capsule Rupture: Incidence Rate, Associated Characteristics and Visual Outcomes
Authors: Muliha Rahman
Published: January 2023

Purpose: To see the Incidence rate, Risk factors, Associations, and Visual outcomes of posterior capsule rupture (PCR). Methods: A cross sectional study was done of all patients with PCR from June to November 2021 in a Tertiary eye care Hospital. In this study, distribution of the respondents by age, the morphology of cataract, risk factors for PCR, Surgeon’s experience, percentage of Phaco and SICS, in which steps of surgery PCR occurred, implantation of IOL following PCR were analyzed. The final visual outcome of cases with PCR was measured. Results: Among 7650 patients, who underwent cataract surgery during the study period, 142 had eventful cataract surgery with various per operative complications, and PCR was the most common (n = 94). Most of the study population was in the age group 61-70 years (37.2%). About 45% were male, and 55% were female. Among 94 cases, PCR occurred in 65 patients (69.1%) during Phaco and 29 (30.8%) cases during SICS. There was no statistically significant difference between Phaco and SICS for PCR (> 0.05). In most patients (26.1%), PCR occurred during cataract surgeries irrigation and aspiration step. The most common risk factors for developing PCR were small pupil (10.6%) and corneal opacity (9.5%). PCR was higher by trainee surgeons rather than by senior surgeons. There was a statistically significant improvement in postoperative visual acuity even when PCR occurred during surgery (P< 0.001). Conclusions: PCR occurs in all cataract surgeries and is the main intraoperative complication. This study identified the incidence rate and risk factors of occurring PCR during cataract surgery in a tertiary eye hospital of Bangladesh, which may assist in the application of preventive measures to decrease rates of PCR. Eyes having posterior capsule rupture at the time of cataract surgery have a significant risk of reduced visual acuity.
The Road to Perfectionism in the Surgical Field: How Resident/ Young Ophthalmologist can become Perfect Ophthalmic Surgeon?
Authors: Suresh K Pandey
Published: January 2023

Medicine is a field where one needs to consistently aim for perfection in order to build their competitive edge and retain optimum perfection. Surgery, ophthalmology and medicine all require a lifetime of learning, and learning requires repetition with aim of perfection. Entering into the surgical field (ophthalmology) is another critical stage where your life is on the verge of transformation as you make a career choice that is for the rest of your life. Moreover, ophthalmic surgery is a field that demands nothing less than perfection as even the most little mistake can lead compromised vision or even blindness. During recent years most of the ophthalmic residents are not getting sufficient surgical cases for learning/mastering the eye surgery in most of the training institutes in India. What are the qualities of perfect surgeon? How resident or young ophthalmologist can learn these qualities? Why do we need to become perfect surgeons – especially when it comes to eye surgery and ophthalmology? Ophthalmologic surgeries are very delicate, highly crucial in nature. Any minor mistake can lead the patient to irrevocable damage in form of blindness or other serious visual impairment. This makes eye surgeries riskier than any other and require perfect surgeons on the list to execute surgeries and minimize the damage risk. In this article the authors share some pearls for learning and mastering eye surgery to become a perfect ophthalmic surgeon.
Unique Optical Coherence Tomography Imaging in Spontaneous Closure of Full Thickness Macular Hole Post Laser Photocoagulation
Authors: A Goyal
Published: January 2023

Purpose: To study events in spontaneous full thickness macular hole (FTMH) closure following laser photocoagulation (LP). Methods: Retrospective case study of a patient of spontaneous FTMH closure documented by SD-OCT following laser. Results: A 51-year-old lady presented with FTMH and a subclinical retinal detachment (RD) in her right eye. LP for subclinical RD was done and surgery for FTMH was advised. On day of surgery, repeat SD-OCT showed spontaneous closure of FTMH with an outer retinal defect, following which surgery was abandoned. Conclusion: Spontaneous PVD induction relieves antero-posterior traction and Inner limiting membrane (ILM) micro breaks relieves tangential traction, which can result in spontaneous closure of FTMH.
Analysis Of Student Responses Toward Sets-Based Discovery Learning
Authors: Azalia Aisha , Muttaqiin Arief
Published: January 2023

This study aimed to describes student responses to the SETS-based discovery learning in class VII.1 of SMP N 30 Padang. The form of study was research sample were by questionnairre to 30 students. Data were collected using questionnaire for classroom learning process including response and also reaction criteria with interest in learning and critical thinking students. The data were analysed by using likert scale, and the research results showed that the learning process was conducted with  data analysis is good. This study prove that SETS based discovery leaning  was very suitable for teaching of interaction of living things and giving positive respon from students.
DEVELOPMENT OF LKPD PROBLEM BASED LEARNING MODEL BASED ON COGNITIVE CONFLICT IN ADITIVE AND ADDICTIVE MATERIALS OF CLASS VIII SMP/MTs
Authors: DEZOLA RESTU VANNI , Hardeli Hardeli
Published: January 2023

To produce Students Worksheet Using Problem Based Learning Based on Cognitive Conflict at Additive and Addictive Substance Material and explain the level of validity and practicality of worksheet. The type of research is used Research and Development or Research and Development (R&D) using the Plomp Development model which consists of three stages: Preliminary research, prototyping stage, and assessment stage. The research instrument used the form of a questionnaire for validity sheet and practicality of Problem Based Learning Based on Cognitive Conflict at Additive and Addictive Substance Material, it was validated by 4 validators consisting of 2 lecturers of Natural Science FMIPA UNP, and 2 teachers from SMP N 31 Padang. The practicality test was conducted with science teachers of SMP N 31 Padang and students of class VIII SMP N 31 Padang. This research produced a problem based learning based on cognitive conflict on additive and addictive with a mean moment of kappa is a very high level of validity. The result of the teacher practicality test and the practicality test of the students obtained an average of kappa moments sequentially with very high degree of practicality.

To produce Students Worksheet Using Problem Based Learning Based on Cognitive Conflict at Additive and Addictive Substance Material and explain the level of validity and practicality of worksheet. The type of research is used Research and Development or Research and Development (R&D) using the Plomp Development model which consists of three stages: Preliminary research, prototyping stage, and assessment stage. The research instrument used the form of a questionnaire for validity sheet and practicality of Problem Based Learning Based on Cognitive Conflict at Additive and Addictive Substance Material, it was validated by 4 validators consisting of 2 lecturers of Natural Science FMIPA UNP, and 2 teachers from SMP N 31 Padang. The practicality test was conducted with science teachers of SMP N 31 Padang and students of class VIII SMP N 31 Padang. This research produced a problem based learning based on cognitive conflict on additive and addictive with a mean moment of kappa is a very high level of validity. The result of the teacher practicality test and the practicality test of the students obtained an average of kappa moments sequentially with very high degree of practicality.

Keywords: Students Worksheets, Problem Based Learning Based On Cognitive Conflict, Additive and Addictive
The Role of Prior Online Learning Experience on Student Community of Inquiry, Engagement, and Satisfaction Scores
Authors: Duha Mohammad Shams Ud , Richardson Jennifer C. , Maeda Yukiko , Kucuk Sevda
Published: January 2023

The increase in online education creates a need to explore how learning outcomes, student satisfaction, and student perceptions about online courses are affected by prior online learning experiences. This study examined the role of prior online learning experience on students’ perceived cognitive presence, social presence, teaching presence, engagement, and satisfaction. The archival data of online learners at a large midwestern university (a total n=878), including survey responses related to Community of Inquiry (CoI), engagement, and satisfaction, were utilized to conduct statistical analyses to determine whether student responses differed by the number of online courses taken previously. We found that only social presence scores (CoI sub-scale) and emotional engagement scores (engagement sub-scale) differed by the number of the online courses taken. However, the effect size was small. We concluded that student satisfaction, engagement, and perceptions of cognitive and teaching presence are not related to prior online course experiences. Implications are discussed.
Learning How to Teach Languages Online: Voices from the Field
Authors: Meskill Carla , Anthony Natasha , Sadykova Gulnara
Published: January 2023

At this moment, fully online language courses are being taught all around the globe. In addition, blended courses offer an integration of online and live instructional experiences. This study examines who is instructing online language courses and what they point to as additive and advantageous to their online language teaching development. We set out to survey higher education faculty as to how they developed their knowledge and practices. Through an online survey and follow-up synchronous interviews, we asked practicing online language educators about the sources of their expertise. The resulting dataset has much to inform professional development and instructional support generally, as well as broader research and educator communities regarding the ongoing, open-ended, peer-supported, and social nature of this kind of educator learning. As more language educators move their instruction online, the question of how to maximize the pedagogical potential of the new medium can best be addressed by those who have successfully made and embraced this move.
College Students’ Belonging and Loneliness in the Context of Remote Online Classes during the COVID-19 Pandemic
Authors: Hansen-Brown Ashley , Sullivan Sean , Jacobson Brianna , Holt Blake , Donovan Shaelyn
Published: January 2023

The COVID-19 pandemic has drastically affected how higher education operates, but relatively little is known about its effects on students enrolled in remote online classes. Across two data collection timepoints, we sought to examine college students’ experiences, focusing particularly on their sense of belonging/loneliness, their course formats, and their experiences in the pandemic. Though some findings differed between data collected in fall 2020 and in spring 2021, we generally found that students’ belonging/loneliness was linked with their class format, aspects of their virtual classes, social contact, and experiences in the pandemic. This research demonstrates the importance both of understanding students’ experiences in general and of continuing to study students’ experiences as we progress from one stage of the pandemic to the next.
Student Webcam Behaviors and Beliefs: Emergent Norms, Student Performance, and Cultural Differences
Authors: Dennen Vanessa P. , Yalcin Yasin , Hur Jaesung , Screws Bruce
Published: January 2023

This study presents findings from a survey of 2298 university students from three countries (South Korea, Turkey, United States) focused on their use of and beliefs about webcams to support synchronous learning, including behaviors such as turning cameras on and multitasking. Additionally, it explores differences due to national culture, school achievement, and classroom seating preferences. As expected, findings show synchronous learning use increased during the pandemic. Student preferences for passive viewing behaviors are strong, along with preferences for keeping cameras off. Differences based on classroom seating preferences suggest that students who sit at the front are more likely than their peers to make decisions about webcam use based on involvement, attention, and preparedness. Cultural differences suggest different pedagogical expectations. Multitasking proved to be a complex behavior and is not always linked to poor achievement outcomes. This study has implications both for future research directions on synchronous learning, student webcam practices, and achievement and for how instructors design synchronous classes.
Scaffolding a Culminating Assignment Within a Community and Task-based MOOC
Authors: Quintana Rebecca M. , Aguinaga Jacob M.
Published: January 2023

We aim to understand the impact of scaffolds within a digital workbook to facilitate self-directed learning for learners completing a final project within a community and task-based MOOC. Optional reflection and articulation prompts were embedded in the tool support assignment development. Workbook use was prevalent, with 65% of learners using it to some extent. Our qualitative analysis revealed that assignment responses associated with substantial workbook use were A) informally written and loosely connected to assignment objectives (36%), or B) well-articulated and connected to assignment objectives (29%). Responses associated with little to no workbook use were C) superficial or uncontextualized (29%), or D) consistent with type “B” responses (6%). We discuss implications for instructors and learning designers in scaffolding complex projects in MOOCs.