bluuebunny/crossref_metadata_2025_split huggingface dataset:
A solution to the complement of the generalized Luneburg lens problem
Authors: Fonseca Nelson J. G. , Tyc Tomáš , Quevedo–Teruel Oscar 
Published: December 2021

AbstractLenses are of interest for the design of directive antennas and multi-optics instruments in the microwave, terahertz and optical domains. Here, we introduce an optical problem defined as the complement of the well-known generalized Luneburg lens problem. The spherically symmetric inhomogeneous lenses obtained as solutions of this problem transform a given sphere in the homogeneous region outside of the lens into a virtual conjugate sphere, forming a virtual image from a real source. An analytical solution is proposed for the equivalent geodesic lens using the analogy between classical mechanics and geometrical optics. The refractive index profile of the corresponding inhomogeneous lens is then obtained using transformation optics. The focusing properties of this family of lenses are validated using ray-tracing models, further corroborated with full-wave simulations. The numerical results agree well with the predictions over the analyzed frequency bandwidth (10–30 GHz). This virtual focusing property may further benefit from recent developments in the fields of metamaterials and transformation optics.
Electron localization induced by intrinsic anion disorder in a transition metal oxynitride
Authors: Oka Daichi , Hirose Yasushi , Nakao Shoichiro , Fukumura Tomoteru , Hasegawa Tetsuya 
Published: December 2021

AbstractAnderson localization derived from randomness plays a crucial role in various kinds of phase transitions. Although treated as a free variable parameter in theory, randomness in electronic materials is hard to control experimentally owing to the coexisting Coulomb interaction. Here we demonstrate that the intrinsic anion disorder in a mixed-anion system of SrNbO2N induces a significant random potential that overwhelms the Coulomb potential while maintaining the lattice structure. A metal-to-insulator transition is triggered by a chemical modulation of the electron density where the critical electron density is more than three orders of magnitude greater than that predicted by the well-known Mott criterion. The localized electrons show characteristic electrical properties such as temperature-dependent multiple crossovers of conduction mechanisms and a positive magnetoresistance above 50% at low temperature. The large magnetoresistance is attributed to wave-function shrinkage of the localized states and clearly visualizes the anisotropy in the band structure, which indicates a compatibility of the periodicity and randomness.
Microvolume DNA extraction methods for microscale amplicon and metagenomic studies
Authors: Bramucci Anna R , Focardi Amaranta , Rinke Christian , Hugenholtz Philip , Tyson Gene W , Seymour Justin R , Raina Jean-Baptiste 
Published: December 2021

Abstract
Investigating the composition and metabolic capacity of aquatic microbial assemblages usually requires the filtration of multi-litre samples, which are up to 1 million-fold larger than the microenvironments within which microbes are predicted to be spatially organised. To determine if community profiles can be reliably generated from microlitre volumes, we sampled seawater at a coastal and an oceanic site, filtered and homogenised them, and extracted DNA from bulk samples (2 L) and microvolumes (100, 10 and 1 μL) using two new approaches. These microvolume DNA extraction methods involve either physical or chemical lysis (through pH/thermal shock and lytic enzymes/surfactants, respectively), directly followed by the capture of DNA on magnetic beads. Downstream analysis of extracted DNA using both amplicon sequencing and metagenomics, revealed strong correlation with standard large volume approaches, demonstrating the fidelity of taxonomic and functional profiles of microbial communities in as little as 1 μL of seawater. This volume is six orders of magnitude smaller than most standard operating procedures for marine metagenomics, which will allow precise sampling of the heterogenous landscape that microbes inhabit.
Und? Was kannst du jetzt für mich tun?
Authors: Cardinal Claudia 
Published: December 2021

SummaryDie Autorin beschreibt, wie sie eine krebskranke Klientin begleitet, deren baldiger Abschied vom physischen Leben unweigerlich bevorsteht. Der gemeinsame Prozess umfasst unter anderem die sogenannte LebensArt – eine Methode zur Erforschung der Einzigartigkeit der eigenen Persönlichkeit – als auch den Abschied von nahen Menschen. Besondere Aufmerksamkeit kommt in jeder Begleitung auch den sogenannten Abschiedsmonstern zu. Diese gilt es zu verwandeln, damit die Klienten in Frieden gehen können.
Begegnung zum Anfassen
Authors: Wortberg Marie 
Published: December 2021

SummaryAchtsame Berührung vermittelt sterbenden und schwerkranken Menschen in der palliativen Pflege wohltuenden Kontakt, Innehalten und entlastende Hilfen. Konfrontiert mit der Endlichkeit des Lebens und auch Gefühlen von Verlust und Hilflosigkeit der Beteiligten, profitieren Pflegekräfte deutlich von der mit dem Konzept verbundenen (Selbst-) Fürsorge, Teamgesprächen und Unterstützungsangeboten. Drei Beispiele aus der Praxis verdeutlichen die Bedeutung des Innehaltens und des Kontakts für die Begleitung Sterbender.
Antiviral Treatments for Influenza
Authors: Palomba Emanuele , Castelli Valeria , Renisi Giulia , Bandera Alessandra , Lombardi Andrea , Gori Andrea 
Published: December 2021

AbstractInfluenza is an acute respiratory illness caused by the influenza A, B, and C viruses. It can occur in local outbreaks or seasonal epidemics, with possibility to spread worldwide in a pandemic when a novel strain with significant antigenic differences emerges. During the past years, several new drugs have become available, with different accessibility related to specific countries' approval. We have conducted a review of literature, analyzing the most recent data on efficacy and safety of drugs currently available to treat influenza, with a particular attention toward special populations. Efficacy and safety profile of neuraminidase inhibitors (oseltamivir, zanamivir, laninamivir, peramivir) and recently approved cap-dependent endonuclease inhibitor baloxavir marboxil are reported in literature, but still little information is available about special populations such as critically ill patients and patients with a history of chronic respiratory disease. Moreover, the emergence of strains with reduced or no susceptibility to current drugs is a matter of concern, suggesting the need of constant monitoring of viral variants.
Complicação incomum de migração do pino intramedular durante a artroplastia total de joelho – Relato de caso
Authors: Londhe Sanjay Bhalchandra , Shah Ravi Vinod , Banka Paras 
Published: December 2021

ResumoA artroplastia total do joelho (ATJ) é uma das cirurgias mais eficazes para alívio da dor e melhora da função no estágio final da artrose (quando ocorre contato entre os ossos). As várias complicações intraoperatórias da ATJ incluem fratura, lesão em tendão ou ligamentos, e complicações nervosas ou vasculares. Neste artigo, descrevemos uma complicação incomum: a migração do pino intramedular dentro do canal femoral durante a ATJ. Um paciente do sexo masculino de 72 anos foi submetido a ATJ com sistema de estabilização posterior e sacrifício do ligamento cruzado posterior. A porção distal do fêmur foi seccionada, e o equilíbrio foi verificado em extensão. Em seguida, um bloco anteroposterior (AP) cinco em um foi utilizado para seção anterior, posterior, de chanfro, e entalhe. Por apresentar uma saliência medial, o bloco foi deslocado em sentido lateral. Ao fazê-lo, os pinos também tiveram de ser deslocados, e um deles foi inadvertidamente inserido na abertura do canal medular do fêmur criado. Como instrumentos ortopédicos usuais, como pinça reta longa e saca-bocado pituitário não conseguiram remover o pino migrado, uma pinça laparoscópica extralonga foi usada sob controle fluoroscópico para localizar, agarrar e remover o pino migrado.
COVID-19 in Immunocompromised Patients: A Systematic Review
Authors: Stainer Anna , Amati Francesco , Suigo Giulia , Simonetta Edoardo , Gramegna Andrea , Voza Antonio , Aliberti Stefano 
Published: December 2021

AbstractSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was first identified as a novel coronavirus in Wuhan, Hubei province, central China, in December 2019, and is responsible for the 2019-to-present pandemic. According to the most recent data released by the World Health Organization, more than 200 million people have been infected by SARS-CoV-2 so far, and more than 4 million people died worldwide. Although our knowledge on SARS-CoV-2 and COVID-19 is constantly growing, data on COVID-19 in immunocompromised patients are still limited. The aim of the present systematic review is to describe clinical picture, disease severity, proposed treatment regimen, and response to vaccination in patients with different types and severity of immunosuppression.
The Sharma–Tasso–Olver–Burgers equation: its conservation laws and kink solitons
Authors: Hosseini K , Akbulut A , Baleanu D , Salahshour S 
Published: December 2021

Abstract
The present paper deals with the Sharma–Tasso–Olver–Burgers equation (STOBE) and its conservation laws and kink solitons. More precisely, the formal Lagrangian, Lie symmetries, and adjoint equations of the STOBE are firstly constructed to retrieve its conservation laws. Kink solitons of the STOBE are then extracted through adopting a series of newly well-designed approaches such as Kudryashov and exponential methods. Diverse graphs in 2 and 3D postures are formally portrayed to reveal the dynamical features of kink solitons. According to the authors’ knowledge, the outcomes of the current investigation are new and have been listed for the first time.
Fast Radio Bursts as Crustal Dynamical Events Induced by Magnetic Field Evolution in Young Magnetars
Authors: Horvath J. E. , Moraes P. H. R. S. , de Avellar M. G. B. , Rocha L. S. 
Published: December 2021

Abstract
We revisit in this work a model for repeating Fast Radio Bursts based of the release of energy provoked by the magnetic field dynamics affecting a magnetar’s crust. We address the basics of such a model by solving the propagation of the perturbation approximately, and quantify the energetics and the radiation by bunches of charges in the so-called charge starved region in the magnetosphere. The (almost) simultaneous emission of newly detected X-rays from SGR 1935+2154 is tentatively associated with a reconnection behind the propagation. The strength of f-mode gravitational radiation excited by the event is quantified, and more detailed studies of the nonlinear (spiky) soliton solutions are suggested.
Normalization in dynamic speckle analysis for non-destructive monitoring of speed of processes
Authors: Stoykova Elena , Nazarova Dimana , Nedelchev Lian , Levchenko Mikhail , Berberova-Buhova Nataliya , Ivanov Branimir 
Published: December 2021

Abstract
The paper is dedicated to analysis of normalized intensity-based pointwise algorithms for processing dynamic speckle images with spatially varying speckle statistics in non-destructive visualization of regions of faster or slower changes across an object. Both existing and newly proposed algorithms are analyzed. Extraction of speed of changes is done by acquiring correlated in time speckle images formed on the object surface under laser illumination. The studied algorithms have been applied to simulated low and high contrast speckle data. Their performance has been compared to processing of binary patterns as another approach for dealing with varying speckle statistics in the acquired images. The efficiency of the algorithms have been checked on the experimental data, including data in a compressed format. We have proven that the algorithms with normalization at successive instants by a sum of two intensities or a single intensity outperform as a whole the algorithms which apply the time-averaged estimates of the mean value and the variance of speckle intensity.
Performance Analysis of a Cloud Computing System using Queuing Model with Correlated Task Reneging
Authors: Kumar Rakesh , Soodan Bhavneet Singh , Kuaban Godlove Suila , Czekalski Piotr , Sharma Sapana 
Published: December 2021

Abstract
Queuing theory has been extensively used in the modelling and performance analysis of cloud computing systems. The phenomenon of the task (or request) reneging, that is, the dropping of requests from the request queue often occur in cloud computing systems, and it is important to consider it when developing performance evaluations models for cloud computing infrastructures. Majority of studies in the performance evaluation of cloud computing data centres with the use of queuing theory do not consider the fact that the tasks could be removed from queue without being serviced. The removal of tasks from the queue could be due to the user impatience, execution deadline expiration, security reasons, or as an active queue management strategy. The reneging could be correlated in nature, that is, if a request is dropped (or reneged) at any time epoch, and then there is a probability that a request may or may not be dropped at the next time epoch. This kind of dropping (or reneging) of requests is referred to as correlated request reneging. In this paper we have modelled a cloud computing infrastructure with correlated request reneging using queuing theory. An M/M/1/N queuing model with correlated reneging has been used to study the performance analysis of the load balancing server of a cloud computing system. The steady-state as well as the transient performance analyses have been carried out. Important measures of performance like average queue size, average delay, probability of task blocking, and the probability of no waiting in the queue are studied. Finally, some comparisons are performed which describe the effect of correlated task reneging over simple exponential reneging.
Parameter identification of permanent magnet synchronous AC motor based on spectral method
Authors: Cong Yuhao , Ji Qingjiao , Hu Guang-Da 
Published: December 2021

Abstract
This paper establishes a mathematical model with random terms for a permanent magnet synchronous AC motor, which is a nonlinear system using d - axis current, q - axis current and the rotor electric angular speed as state variables. The numerical solution obtained by the Euler-Maruyama method is used as the measurement data. Aiming at the parameter identification of the system, a step-by-step identification method based on the spectral method discretize the system first and then using the least squares is proposed. This method is used to identify multiple parameters of the motor in the same model. In step-by-step identification, firstly by fixing the motor speed, the system is transformed into a linear system, which is used to estimate the resistance, inductance and flux linkage. After that, the speed is not fixed, for the electrical parameters are known, we can identify damping and inertia by using mechanical equations. Finally, the experimental results show that the relative errors of the parameters identified by the proposed method are smaller, which shows the effectiveness of this method for multi-parameter identification.
Wide-angle acousto-optic devices based on isotropic light scattering in biaxial crystals
Authors: Kupreychik M I , Balakshy V I , Pozhar V E 
Published: December 2021

Abstract
Using the example of a rhombic crystal of alpha-iodic acid, a detailed study of new variants of acousto-optic isotropic light scattering in oblique sections of biaxial crystals, whose refractive surface contains a concave portion, is carried out. For these cases, the frequency dependences of the Bragg angles and the ranges of acousto-optic interaction are calculated. The possibility of implementing a unique, simultaneously broadband and wide-angle variant of light scattering is established. It is shown that the two-dimensional transfer function of such acousto-optic geometry has a complex X-shaped structure that has no analogues among uniaxial crystals. The possibility of applying this diffraction regime in light beam spatial filtering devices is studied.
Analysis of chromatic aberrations influence on operation of the tunable AOTF-based source
Authors: Beliaeva A S , Romanova G E , Chertov A N 
Published: December 2021

Abstract
Developing a source with the possibility of tuning in wavelengths based on an acousto-optical tunable filter (AOTF), an essential factor is the ability to provide accurate color coordinates of the simulated color (in the case of developing a color standard for colorimetry) or the required wavelength (in the case of an application for spectral studies). As shown earlier, the choice of the principal layout – confocal or parallel beam path - primarily determines the dimensions and efficiency of using the luminous flux. However, these schemes also need to be analyzed for color or wavelength fidelity, considering other components used in the scheme. The analysis performed allows to identify the optimal scheme to ensure the required color reproduction accuracy and establish the requirements for correcting chromatic aberrations of the components.
2D scanning system of the acousto-optical deflector with high diffraction efficiency
Authors: Pichugina Y V , Garnov S V , Bulkin Y N 
Published: December 2021

Abstract
The paper considers advantages and special features of an acousto-optic method for the development of a functional device for spatial and temporal control of laser light and reports results of investigations to create a two-directional acousto-optic laser scanner with diffraction efficiency as high as 80 percent or better. An acousto-optic deflector on a paratellurite crystal operating under the Bragg diffraction condition with a lithium niobate piezoelectric acoustic transducer was developed and tested experimentally. The results of this work can serve as a basis for the development of prototype functional acousto-optic devices for spatial and temporal control of laser light and their application to create laser television images.
Optimization of operating modes of the weak absorption spectrometer
Authors: Korolenko P V , Vokhnik O M 
Published: December 2021

Abstract
The possibilities of improving the characteristics of a weak absorption spectrometer consisting of a frequency-tunable laser and an external analytical resonator with the test substance are analyzed. The influence of the scanning speed of the laser frequency on the choice of the spectrometer operating modes that provide the required resolution and the required sensitivity of spectral measurements is considered. Particular attention is paid to assessing the role of the interaction of modes in an analytical cavity on the structure of the recorded spectra. It was found that at a high rate of change in the laser frequency and superposition of fields of longitudinal modes, an improvement in the resolving power is combined with a certain decrease in the sensitivity and accuracy of recording weak spectral lines. It is shown that the optimization of the spectrometer operation modes requires correct accounting of the Q-factor of the analytical resonator and the line width of the probe radiation.
Development of a selective assembly card of the «Koadut» lens
Authors: Kachurin Yu.Yu. , Kananykhin O.A. , Levin I.A. 
Published: December 2021

Abstract
The work is devoted to the development of a selective assembly card of the «Koadut» lens, depending on the actual thickness of each of the seven lenses included in the optical scheme of the objective. Criteria for sorting options are substantiated, a macro for processing a file with the results of measurements of actual lens thicknesses, which forms an assembly card, is created. The macro was tested on a test file with a normal distribution of deviations from the nominal value of a batch of one hundred lenses.
Control system for glucose level regulation in peritoneal dialysis
Authors: Zhilo N M , Litinskaia E L , Bazaev N A 
Published: December 2021

Abstract
Kidney failure leads to the serious health issues associated with abnormal water-salt balance. In this case, peritoneal dialysis therapy is often prescribed: 1-2 liters of dialysis solution is administered in peritoneal cavity for 3-4 hours. During this time, due to diffusion and osmosis, toxins and excess water are transferred from blood to solution. One of the method’s downsides is the transition of glucose (osmotic agent) into the bloodstream, which leads to a gradual decrease in the fluid removal rate. To mitigate this problem, one must use the system, which will measure current glucose concentration and inject glucose into solution to compensate absorption. The paper proposes such a control system for automatic regulation of the glucose concentration in peritoneal dialysate solution. Its structure, elements, their functions and characteristics are discussed. Proposed system is capable to work autonomously or can be incorporated into wearable “artificial kidney” device.
Computational fluid dynamics simulation of hemolysis at different levels of circulatory support in the left ventricular assist device Sputnik
Authors: Romanova A , Telyshev D 
Published: December 2021

Abstract
Designing a ventricular assist device is a complex technological process, and testing a finished product requires a significant investment of money and time. Simulation allows research to conduct research early in the development of a device, thereby reducing time and material costs. In this work, the calculation of hemolysis in the left ventricular assist device Sputnik (Sputnik LVAD) is carried out. Three different levels of circulatory support were chosen. For the first level, the following parameters were selected: blood flow rate of 2 L/min. at a rotor speed of 8000 rpm; for the second - 4 L/min, 8500 rpm; for the third - 6 L/min, 9000 rpm. The distribution of scalar shear stresses and the index of hemolysis were obtained from the pathlines of the particles. When comparing three operating points of LVAD Sputnik, hemolysis indices were obtained using the Lagrangian model. The mean hemolysis indeces were 0.0284%, 0.0210%, 0.0155% for LVAD Sputnik operating at a fixed rate of 2, 4, 6 L/min at a pressure of 100 mm Hg, respectively. The calculation results show that the capacity of 6 L/min is better than 2 and 4 L/min.
Study of bioactive molecular systems by gas-phase electron diffraction: examples, limitations and possibilities
Authors: Altova E P , Rykov A N , Shishkov I F 
Published: December 2021

Abstract
The paper is aimed to the development of structural chemistry of biomolecules, which play essential role for living systems. The structures of biogenic amine, adrenaline, was determined using gas phase electron diffraction (GED) technique in comparison with tryptamine and noradrenaline investigation. Possibilities of method and its limitations are shown in application to bioactive molecular systems. The investigations of the molecules in gas phase allows us to find and describe details of their structures, molecular dynamic which leads to the behavior of the substances in the various processes.
A method for presenting biomedical images based on a model of receptive fields of human visual perception
Authors: Antsiperov V E , Kershner V A 
Published: December 2021

Abstract
The paper is devoted to the development of a new method for presenting biomedical images based on local characteristics of the intensity of their shape. The proposed method of image processing is focused on images that have low indicators of the intensity of the recorded radiation, resolution, contrast and signal-to-noise ratio. The method is based on the principles of machine (Bayesian) learning and on samples of random photo reports. This paper presents the results of the method and its connection with modern approaches in the field of image processing.