bluuebunny/crossref_metadata_2025 huggingface dataset:
Search and analysis of giant radio galaxies with associated nuclei (SAGAN)
Authors: Mahato Mousumi , Dabhade Pratik , Saikia D. J. , Combes Françoise , Bagchi Joydeep , Ho L. C. , Raychaudhury Somak
Published: December 2021

Giant radio quasars (GRQs) are radio-loud active galactic nuclei (AGN) that propel megaparsec-scale jets. In order to understand GRQs and their properties, we have compiled all known GRQs (‘the GRQ catalogue’) and a subset of small (size < 700 kpc) radio quasars (SRQs) from the literature. In the process, we have found ten new Fanaroff-Riley type-II GRQs in the redshift range of 0.66 <  z <  1.72, which we include in the GRQ catalogue. Using the above samples, we have carried out a systematic comparative study of GRQs and SRQs using optical and radio data. Our results show that the GRQs and SRQs statistically have similar spectral index and black hole mass distributions. However, SRQs have a higher radio core power, core dominance factor, total radio power, jet kinetic power, and Eddington ratio compared to GRQs. On the other hand, when compared to giant radio galaxies (GRGs), GRQs have a higher black hole mass and Eddington ratio. The high core dominance factor of SRQs is an indicator of them lying closer to the line of sight than GRQs. We also find a correlation between the accretion disc luminosity and the radio core and jet power of GRQs, which provides evidence for disc-jet coupling. Lastly, we find the distributions of Eddington ratios of GRGs and GRQs to be bi-modal, similar to that found in small radio galaxies (SRGs) and SRQs, which indicates that size is not strongly dependent on the accretion state. Using all of this, we provide a basic model for the growth of SRQs to GRQs.
The mass and size of Herbig disks as seen by ALMA
Authors: Stapper L. M. , Hogerheijde M. R. , van Dishoeck E. F. , Mentel R.
Published: December 2021

Context. Many population studies have been performed over the past decade with the Atacama Large millimeter/submillimeter Array (ALMA) to understand the bulk properties of protoplanetary disks around young stars. The studied populations have mostly consisted of late spectral type (i.e., G, K & M) stars, with relatively few more massive Herbig stars (spectral types B, A & F). With Gaia-updated distances, now is a good time to use ALMA archival data for a Herbig disk population study and take an important step forward in our understanding of planet formation.

Aims. The aim of this work is to determine the masses and sizes of all Herbig dust disks observed with ALMA to date in a volume-limited sample out to 450 pc. These masses and sizes are put in the context of the Lupus and Upper Sco T Tauri disk populations.

Methods. ALMA Band 6 and Band 7 archival data of 36 Herbig stars are used, making this work 64% complete out to 225 pc, and 38% complete out to 450 pc also including Orion. Using stellar parameters and distances, the dust masses and sizes of the disks are determined via a curve-of-growth method. Survival analysis is used to obtain cumulative distributions of the dust masses and radii.

Results. Herbig disks have a higher dust mass than the T Tauri disk populations of Lupus and Upper Sco by factors of ~3 and ~7 respectively. In addition, Herbig disks are often larger than the typical T Tauri disk. Although the masses and sizes of Herbig disks extend over a similar range to those of T Tauri disks, the distributions of masses and sizes of Herbig disks are significantly skewed toward higher values. Lastly, group I disks are more massive than group II disks. An insufficient number of group II disks are observed at sufficient angular resolution to determine whether or not they are also small in size compared to group I disks.

Conclusions. Herbig disks are skewed towards more massive and larger dust disks compared to T Tauri disks. Based on this we speculate that these differences find their origin in an initial disk mass that scales with the stellar mass, and that subsequent disk evolution enlarges the observable differences, especially if (sub)millimeter continuum optical depth plays a role. Moreover, the larger disk masses and sizes of Herbig stars could be linked to the increasing prevalence of giant planets with host star mass.
High-resolution images of two wiggling stellar jets, MHO 1502 and MHO 2147, obtained with GSAOI+GeMS
Authors: Ferrero L. V. , Günthardt G. , García L. , Gómez M. , Kalari V. M. , Saldaño H. P.
Published: December 2021

Aims. We investigated the possible cause–effect relation between the wiggling shape of two stellar jets, MHO 1502 and MHO 2147, and the potential binarity of the respective driving stars.

Methods. We present high-angular-resolution H2 (2.122 μm) and K-band images obtained with the Gemini South Adaptive Optics Imager (GSAOI) and the Gemini Multi-conjugate Adaptive Optics System (GeMS). The profiles of the jets are depicted in detail by the H2 images. We used K-band data to search for potential close companions to the previously suggested exciting sources, and used archive data to investigate these sources and the environments in which the jets are located. We also applied a model to reproduce the wiggling profiles of the jets.

Results. MHO 1502 is composed of a chain of knots delineating the wiggling jet, suggesting that the driving source emitted them in an intermittent manner. Our K-band image of the previously proposed exciting star, IRAC 18064, shows two sources separated by ~240 AU, hinting at its binarity. However, as IRAC 18064 is located off the jet axis at ~2064 AU, it is questionable as to whether this source is the true exciting star. Moreover, the orbital model centred on IRAC 18064 suggests a binary companion at a much greater distance (~2200 AU) than the nearby star (at ~240 AU). On the other hand, the orbital model centred on the axis provides the best fits. Nevertheless, the precession model centred on the axis cannot be discarded, despite having larger residuals and χ2. MHO 2147 displays an S-shaped gentle continuous emission in H2. We identify two other jets in the field of MHO 2147: a previously reported quasi-perpendicular jet, MHO 2148, and a third jet adjacent to MHO 2147. The model that best fits the morphology of the MHO 2147 jet and that of its adjacent jet is precession. The exciting source of MHO 2147 may be a triple system.
Effects of social and economic factors on the attitudes of diabetic patients towards self-care behaviors in Iran
Authors: Gholamzadeh Nikjoo Raana , Nikbakht Haniye , Partovi Yegane , Jafari Koshki Tohid
Published: December 2021

Background: One of the most common chronic diseases is diabetes, which self-care has a very significant role in reducing its complications. The aim of this study was to investigate the effect of social and economic factors on the attitude of diabetic patients towards self-care behaviors. Methods: The current study is a cross-sectional study conducted in 2019. The sample included 170 patients with diabetes referring to the clinics affiliated to the Tabriz University of Medical Sciences. Data were collected using a previously developed questionnaire through interview. Results: Out of participants in the study, had a positive attitude towards self-care behaviors of type 2 diabetes. We observed significant association between attitude towards self-care behaviors in type 2 diabetes and membership in real and virtual groups (P < 0.001), education (P < 0.001) support of family members (P < 0.001), household income (P = 0.01). Conclusion: Regarding the correlation between certain social and economic variables, and patient attitude towards self-care in diabetes, as well as the effects of attitude in performing self-care behaviors, and the beneficial results of these behaviors in disease control, correct methods must be adapted to control these variables both materially and spiritually. Some of the methods suggested by the researchers are holding frequent educational classes for these people, providing suitable pamphlets, allocating suitable environments and green spaces for diabetic patients, creating suitable and fun virtual groups, identifying type 2 diabetic patients who are not supported by families or do not have enough income and creating suitable group spaces for these people.
Sterben besser verstehen
Authors: Meyer Stefan , Bollig Georg
Published: December 2021

Die Hospiz- und Palliativversorgung sind in Deutschland zu wenig bekannt. Bis zu 90 % der Deutschen benötigen im Sterbeprozess Palliativversorgung, aber nur 30 % erhalten sie. Es ist wichtig, Menschen auf die Sterbebegleitung ihrer Angehörigen vorzubereiten und die Versorgungsnetzwerke bekannt zu machen. Die meisten Menschen wünschen sich, möglichst schmerzfrei, nah am Gewohnten, selbstbestimmt, sozial eingebunden und gut versorgt aus dem Leben zu scheiden.
Resveratrol treatment does not reduce arterial inflammation in males at risk of type 2 diabetes: a randomized crossover trial
Authors: Boswijk Ellen , de Ligt Marlies , Habets Marie-Fleur J , Mingels Alma M.A. , van Marken Lichtenbelt Wouter D. , Mottaghy Felix M. , Schrauwen Patrick , Wildberger Joachim E. , Bucerius Jan
Published: December 2021

Purpose Resveratrol has shown promising anti-inflammatory effects in in vitro and animal studies. We aimed to investigate this effect on arterial inflammation in vivo.

Methods This was an additional analysis of a double-blind randomized crossover trial which included eight male subjects with decreased insulin sensitivity who underwent an 18F-fluoroxyglucose (18F-FDG) PET/CT after 34 days of placebo and resveratrol treatment (150 mg/day). 18F-FDG uptake was analyzed in the carotid arteries and the aorta, adipose tissue regions, spleen, and bone marrow as measures for arterial and systemic inflammation. Maximum target-to-background ratios (TBRmax) were compared between resveratrol and placebo treatment with the non-parametric Wilcoxon signed-rank test. Median values are shown with their interquartile range.

Results Arterial 18F-FDG uptake was non-significantly higher after resveratrol treatment (TBRmax all vessels 1.7 (1.6–1.7)) in comparison to placebo treatment (1.5 (1.4–1.6); p=0.050). Only in visceral adipose tissue, the increase in 18F-FDG uptake after resveratrol reached statistical significance (p=0.024). Furthermore, CRP-levels were not significantly affected by resveratrol treatment (p=0.091).

Conclusions Resveratrol failed to attenuate arterial or systemic inflammation as measured with 18F-FDG PET in subjects at risk of developing type 2 diabetes. However, validation of these findings in larger human studies is needed.
High-Frequency Positive Pressure Ventilation as Primary Rescue Strategy for Patients with Congenital Diaphragmatic Hernia: A Comparison to High-Frequency Oscillatory Ventilation
Authors: Gerall Claire , Wallman-Stokes Aaron , Stewart Latoya , Price Jessica , Kabagambe Sandra , Fan Weijia , Hernan Rebecca , Wung Jen , Sahni Rakesh , Penn Anna , Duron Vincent
Published: December 2021

Objective The aim of this article was to evaluate high-frequency positive pressure ventilation (HFPPV) compared with high-frequency oscillatory ventilation (HFOV) as a rescue ventilation strategy for patients with congenital diaphragmatic hernia (CDH). HFPPV is a pressure-controlled conventional ventilation method utilizing high respiratory rate and low positive end-expiratory pressure.

Study Design Seventy-seven patients diagnosed with CDH from January 2005 to September 2019 who were treated with stepwise progression from HFPPV to HFOV versus only HFOV were included. Fisher's exact test and the Kruskal–Wallis test were used to compare outcomes.

Results Patients treated with HFPPV + HFOV had higher survival to discharge (80 vs. 50%, p = 0.007) and to surgical intervention (95.6 vs. 68.8%, p = 0.003), with average age at repair 2 days earlier (p = 0.004). Need for extracorporeal membrane oxygenation (p = 0.490), inhaled nitric oxide (p = 0.585), supplemental oxygen (p = 0.341), and pulmonary hypertension medications (p = 0.381) were similar.

Conclusion In CDH patients who fail respiratory support with conventional ventilation, HFPPV may be used as an intermediary mode of rescue ventilation prior to HFOV without adverse effects.

Key Points
Attributable Mortality for Pediatric and Neonatal Central Line-Associated Bloodstream Infections in Greece
Authors: Karagiannidou Sofia , Kourlaba Georgia , Zaoutis Theoklis , Maniadakis Nikolaos , Papaevangelou Vassiliki
Published: December 2021

Central line-associated bloodstream infections (CLABSIs) are the most frequent pediatric hospital-acquired infections and significantly impact outcomes. The aim of this study was to estimate the attributable mortality for CLABSIs in pediatric and neonatal patients in Greece. A retrospective matched-cohort study was performed, in two tertiary pediatric hospitals. Inpatients with a central line in neonatal and pediatric intensive care units (NICUs and PICUs), hematology/oncology units, and a bone marrow transplantation unit between June 2012 and June 2015 were eligible. Patients with confirmed CLABSI were enrolled on the day of the event and were matched (1:1) to non-CLABSI patients by hospital, hospitalization unit, and length of stay prior to study enrollment (188 children enrolled, 94 CLABSIs). Attributable mortality was estimated. During the study period, 22 patients with CLABSI and nine non-CLABSI patients died (23.4 vs. 9.6%, respectively, p = 0.011), leading to an attributable mortality of 13.8% (95% confidence interval [CI] = 3.4–24.3%). Children in PICUs were more likely to die, presenting an attributable mortality of 20.2% (95% CI = − 1.4–41.8%), without reaching, however, statistical significance. After multiple logistic regression, patients with CLABSI were four times more likely to die (odds ratio [OR] = 4.29, 95% CI = 1.28–14.36, p = 0.018). Survival analysis showed no difference in time to death after study enrollment between patients with CLABSI and non-CLABSI patients (log-rank p = 0.137, overall median survival time = 7.8 months). Greek pediatric mortality rates are increased by the CLABSI occurrence, highlighting the importance of infection prevention strategies.
Study of magnetic force between the two magnets for the torque and speed evaluations of rim-driven motor
Authors: Liu Siqing , Duan Franklin Li , Li Xiaocui
Published: December 2021

A new quasi-Coulomb relation between magnetic force vs distance, magnetic flux density, and magnetic pole area is proposed in this paper based on the empirical analysis on the magnetic force vs distance measurements. A simple device is designed and fabricated to measure the repulsive/attractive magnetic force between two magnets. The measurement results show that the relationship between the magnetic force and distance is similar to Coulomb’s electrostatic law, but the attraction is greater than the repulsion. The magnetic force is proportional to the integral of the magnetic flux density with the areas of the magnetic pole. This quasi-Coulomb relationship is useful to evaluate the torque and speed of a rim-driven motor, which plays an important role in electrified propulsion in green aviation technology.
Thermal boundary conductance across Co/Cu interfaces with spin–lattice interactions
Authors: Ge Yijun , Zhou Yanguang , Fisher Timothy S.
Published: December 2021

This work combines first-principles calculations, spin–lattice dynamics, and the non-equilibrium Green’s function (NEGF) method to compute thermal boundary conductance at a three-dimensional Co–Cu interface, considering spin–lattice interactions. Spin–lattice interactions are quantified through exchange interactions between spins, and the exchange constants are obtained from first-principles calculations. Equilibrium molecular dynamics is used to calculate the heat flux across the interface after the spin and lattice subsystems are in equilibrium. Because of the weak interaction between Co and Cu layers adjacent to the interface, spin-wave transmission is low. Spins are scattered by phonons inside the Co contact, and interfacial thermal conductance is reduced. We also compare the results to the NEGF method. Phonon and magnon scattering rates are incorporated into Büttiker probes attached to the device. The NEGF method shows a similar trend in thermal boundary conductance with spins included. Green’s function is solved recursively; therefore, it can be applied to large devices.
A perspective of twisted photonic structures
Authors: Chen Jialin , Lin Xiao , Chen Mingyuan , Low Tony , Chen Hongsheng , Dai Siyuan
Published: December 2021

Moiré superlattices—twisted van der Waals (vdW) structures with small angles—are attracting increasing attention in condensed matter physics, due to important phenomena revealed therein, including unconventional superconductivity, correlated insulating states, and ferromagnetism. Moiré superlattices are typically comprised of atomic layers of vdW materials where the exotic physics arises from quantum electronic coupling between adjacent atomic layers. The abundant phenomena revealed in moire electronics have motivated intensive studies on their photonic counterpart. In addition to vdW materials, twisted photonic systems can also be comprised of metamaterials, metasurfaces, and photonic crystals, mediated by interlayer electromagnetic coupling instead. The interplay between short-ranged interlayer quantum and long-ranged electromagnetic coupling in twisted structures is expected to yield rich phenomena in nano-optics. This study reviews recent progress in twisted structures for nanophotonics and outlook for emerging topics, opportunities, fundamental challenges, and potential applications.
Hysteresis control using a DC magnetic field in an argon inductively coupled plasma
Authors: Kim Tae-Woo , Lee Moo-Young , Chung Chin-Wook
Published: December 2021

Control of the hysteresis phenomenon in a high-pressure (250 mTorr) argon inductively coupled plasma was experimentally investigated by applying a DC magnetic field. Electron energy probability functions (EEPFs) were measured with and without DC magnetic fields to obtain electron densities. Without the magnetic field, a hysteresis loop is clearly observed during the E and H mode transitions, but surprisingly, when 20 G of DC magnetic field is applied, the hysteresis loop gets smaller, and it vanishes completely when the applied DC magnetic field is increased to over 40 G. Measured EEPFs show that there is a significant evolution of the EEPFs by DC magnetic field. The EEPF without magnetic field is a Druyvesteyn distribution, but evolves to a Maxwellian-like distribution under a strong DC magnetic field condition. This evolution of the EEPF causes significant reduction in the collisional energy loss εc in E-mode. The evolution of EEPFs is explained by a decrease in Ohmic power absorption of low-energy electrons and an increase in electron–electron collisions, and the vanishing of the hysteresis is explained by the suppression of nonlinear changes in EEPF and nonlinear changes in collisional energy loss.
Spherical billiards with almost complete escape
Authors: Dettmann Carl P. , Rahman Mohammed R.
Published: December 2021

A dynamical billiard consists of a point particle moving uniformly except for mirror-like collisions with the boundary. Recent work has described the escape of the particle through a hole in the boundary of a circular or spherical billiard, making connections with the Riemann Hypothesis. Unlike the circular case, the sphere with a single hole leads to a non-zero probability of never escaping. Here, we study variants in which almost all initial conditions escape, with multiple small holes or a thin strip. We show that equal spacing of holes around the equator is an efficient means of ensuring almost complete escape and study the long time survival probability for small holes analytically and numerically. We find that it approaches a universal function of a single parameter, hole area multiplied by time.
A reduced-order model for the near wake dynamics of a wind turbine: Model development and uncertainty quantification
Authors: Qatramez Ala' E. , Foti Daniel
Published: December 2021

Wind turbine power production and its variability are affected by unsteady, turbulent structures that are induced in the wake and emerge over a range of disparate length scales. However, the inclusion of the unsteady dynamics in wake models remains difficult in kinematic modeling where steady-state conditions are assumed. We develop and quantify the uncertainty of an unsteady wake model by leveraging model-order reduction. The wake is modeled as a dynamical system based on dynamic mode decomposition and compressive sensing, where the system is reduced by designating an objective function to select energetic turbulent structures represented by dynamic modes. A series of large-eddy simulations are undertaken using the actuator line model and the actuator surface with nacelle model for training and testing data. Differences in the turbine parameterizations of near wake simulations are used to identify how modes are related to turbulent structures and are selected through compressive sensing. The results showed that the flow field can be constructed with few modes. The modes are the most energetic and have frequencies related to pertinent features such as tip and hub vortices. While the error in the training phase is dependent on the number of modes, the relative error remains less than 6% and is largely independent of the number of modes during the prediction phase if certain modes are retained. The error accumulates over time near the turbine blades. However, error accumulation does not have a significant impact on the prediction of instantaneous velocity in the wake further downwind.
Vacuum ultraviolet photoexcitation and photofragment spectroscopic studies of 14N15N between 109000 and 117500 cm−1
Authors: Liu Min , Jiang Pan , Cheng Min , Gao Hong
Published: December 2021

In this study, we employed a newly built time-slice velocity-map ion imaging setup, equipped with two tunable vacuum ultraviolet (VUV) laser sources, to obtain the first comprehensive high-resolution photoexcitation and photofragment excitation spectra of 14N15N in the VUV photon energy range 109 000–117 500 cm−1. The spectroscopic simulation program PGOPHER was used to analyze the rotationally resolved spectra. Band origins, rotational constants, and isotope shifts compared with those of 14N2 have been obtained for 31 electric-dipole-allowed vibrational states of 14N15N in the aforementioned energy range. These spectroscopic parameters are found to depend on the vibrational quantum number irregularly. Systematic perturbations of the rotational transition energies and predissociation rates within individual absorption bands have also been observed. These are proved to be caused by the strong homogeneous interactions between the valence b′1Σu+ state and the Rydberg cn′ 1Σu+ states, and between the valence b1Πu states and the Rydberg o31Πu states. Heterogeneous interactions between the Rydberg cn1Πu states and cn′1Σu+ states also play an important role.
On detecting dynamical regime change using a transformation cost metric between persistent homology diagrams
Authors: Dee Algar Shannon , Corrêa Débora C. , Walker David M.
Published: December 2021

This work outlines a pipeline for time series analysis that incorporates a measure of similarity not previously applied between homological summaries. Specifically, the well-established, but disparate, methods of persistent homology and TrAnsformation Cost Time Series (TACTS) are combined to provide a metric for tracking dynamics via changing homological features. TACTS allows subtle changes in dynamics to be accounted for, gives a quantitative output that can be directly interpreted, and is tunable to provide several complementary perspectives simultaneously. Our method is demonstrated first with known dynamical systems and then with a real-world electrocardiogram dataset. This paper highlights inadequacies in existing persistent homology metrics and describes circumstances where TACTS can be more sensitive and better suited to detecting a variety of regime changes.
Gas velocimetry based on infrared laser-induced fluorescence
Authors: Song Zihao , Wang Weitian , Zhu Ning , Chao Xing
Published: December 2021

A novel method for gas velocity field measurements by means of infrared molecular tagging velocimetry is reported with proof-of-principle demonstration in a carbon dioxide (CO2) axisymmetric turbulent jet. Infrared laser-induced fluorescence utilizes the resonant vibrational energy level transitions of small gas molecules, such as CO2, to “tag” and trace the flow of the molecules by taking subsequent images of the infrared emission. Spectroscopic model of the molecular vibrational energy transfer processes is taken into account to design and optimize the measurement scheme. The infrared images are then analyzed, with detailed consideration of molecular diffusion, lateral velocity, and fluorescence lifetime, to yield quantitative velocity field distribution. The radial velocity distributions in the jet main region, with velocities ranging from 7 to 50 m/s, are obtained and shown to be in excellent agreement with theoretical predication and previous experimental works. Velocity uncertainties are discussed and estimated to be 7.7%, 6.7%, 6.1% for Re = 104, 2×104, 3×104 (maximum velocity uc=18.3,34.6,50.5 m/s), respectively. Spatial resolution along the laser beam is estimated to be 107 μm. To the best of the authors' knowledge, this is the first work of infrared molecular tagging velocimetry. With powerful excitation lasers targeting strong infrared molecular absorption transitions, this technique presents great potential for simultaneous flow-scalar field measurements at much-improved accuracy, spatial and temporal resolution, that can be used for the study of low-speed micro-flows, or instantaneous snapshots of turbulent flows.
Effect of DC electric field on THz radiation field and efficiency of dark hollow laser beam in plasma
Authors: Amouamouha Mitra , Bakhtiari Farhad , Ghafary Bijan
Published: December 2021

In the present study, a schematic has been proposed for generating terahertz (THz) radiation by beating of two dark hollow (DH) laser beams in plasma when a DC electric field is applied with a perpendicular direction. The small field amplitude and the radiation’s efficiency produced by DH laser beams in plasma as well as DC electric generation and exertion comfortability motivated us to enhance these parameters by applying a perpendicular DC electric field. It was found that applying a DC electric field in addition to increasing the THz field amplitude and efficiency caused the generation of a special THz field, which has an exclusive pattern tunable by the variation of the electric field amplitude. It is shown that due to mutual effects between the spatial profile of the beams and the electric field, the THz radiation field and efficiency have the maximum point that can be used for the production of a desired THz frequency.
Spatiotemporally resolved characteristics of arc plasma in non-thermal multi-arc generator at atmospheric pressure
Authors: Huang Y. J. , Lin Q. F.
Published: December 2021

The spatiotemporally resolved characteristics of arc plasma in a non-thermal multi-arc generator with three high-voltage electrodes and a common grounded one were investigated by means of arc current signal, discharge image signal, and image analysis. Experimental results show that the spatial distribution of multi-arc plasma can be adjusted by the gas flow rate, and multi-arc plasma tends to distribute in the center of the arc chamber with the decrease in the gas flow rate. Once the confluence of three independent arc columns occurs, a common arc root will be shared by three arcs. The common arc-root attachment varies between constricted state and diffuse state, and the variation duration was in a cycle of about 1 ms, which is associated with beat vibration caused by the small deviation among the frequencies of three arc currents. This phenomenon suggests that the size of the arc root attachment can be adjusted by means of the frequency of the driving power supply.
Propagation of evanescent wave through surface-attached nanobubbles: A 2D simulation
Authors: Song Luming , Chan Chon U. , Lin Hongyi , Ohl Claus-Dieter , Sun Dong
Published: December 2021

We numerically study the propagation of evanescent waves at the interface between water and glass. Due to the existence of surface-attached nanobubbles, the intensity of the evanescent wave passed into water increases by 30 times, which can be used in the dark-field inspection. The relationship between the intensity of the evanescent wave and contact angle is found and analyzed. It provides a possible method to measure the contact angle. Additionally, the theoretical distribution of bright and dark areas on nanobubbles is consistent with experimental data, where the middle of the nanobubble is darker than the edge. The right edge of the bubble is brighter than the left edge, which corresponds to the incident direction of the light source.
Extensional rheometry of model liquids: Simulations of filament stretching
Authors: Hassager Ole , Wang Yanwei , Huang Qian
Published: December 2021

Polymeric liquid bridges are known to fail during extension. This phenomenon of failure seemingly calls into question the operating principle of filament stretching rheometers. In these devices, a polymeric sample is initially placed between two plates. The sample is then stretched into a liquid bridge by moving the plates apart in a specified way. We here show that a steady extensional viscosity can be measured if the plates are separated in such a way that the stretch rate in the filament symmetry plane is kept constant, even for liquids highly prone to instability. Moreover, reliable measurements of the stress during a relaxation phase can be obtained as well. The conclusions are based on simulations for a number of constitutive equations, including the Newtonian liquid, the Oldroyd-B model, the differential non-stretch Rolie–Poly model, and the integral Doi–Edwards model with and without associated stretch relaxation dynamics.
Photon-Tissue Interactions in Biomedical Imaging
Authors: Jacques Steven L.
Published: December 2021

This chapter considers examples of how the optical properties and architecture of a tissue affect the imaging and spectroscopy of the tissue. Examples include (1) why skin and gingiva look pink not orange, (2) adding cream to coffee to illustrate the interactive effect of absorption and scattering on observed color, (3) quantifying the blood volume of microvasculature with vessels of an apparent diameter, and (4) how optical properties affect the observed fluorescence of a tissue. Also, the chapter considers how optical properties affect photon-tissue interactions during therapeutic and surgical laser/light procedures. Examples include (1) how tissue properties affect the dosimetry of photodynamic therapy (photo-chemical interaction), (2) how tissue properties control the volume of tissue heated by a pulsed laser (photo-thermal interaction), and (3) how tissue properties influence spallation, cavitation, and explosive vaporization (photo-mechanical interactions).
Super-Resolution Imaging through Laser-Scanning Microscopy
Authors: Tortarolo Giorgio , Castello Marco , Vicidomini Giuseppe
Published: December 2021

Fluorescence super-resolution (SR) microscopy has definitely advanced from the initial scepticism towards becoming the replacement of conventional microscopy. Indeed, thanks to several advancements in technologies (e.g., lasers, detectors, electronics, fluorescent probes) and new concepts (e.g., illumination strategies, labeling protocols, data analysis), SR microscopy is continuously closing the gap to electron microscopy in terms of spatial resolution, and, just as important, SR microscopy is becoming much gentler on living tissue samples. In this chapter, we briefly introduce fluorescence SR microscopy, followed by a discussion on conventional classification: wide-field-based vs laser-scanning-based techniques. We then focus only on the class of laser-scanning microscopy by describing their strategies to achieve sub-diffraction resolution. In particular, we analyze the pros and cons of confocal, image-scanning, stimulated emission depletion, and reversible saturable optical fluorescence transition microscopy, which currently represent the most mature laser-scanning-based SR techniques. We evaluate these techniques from a theoretical point of view and in terms of imaging of living biological systems. Finally, we envisage some perspectives.
Multiphoton Imaging
Authors: Giacomelli Michael
Published: December 2021

Multiphoton techniques overcome some of the limitations of conventional fluorescence and confocal microscopy, enabling deep, volumetric imaging through scattering tissue. Multiphoton absorption, where two or more photons are simultaneously absorbed, can occur only under strong optical fields. This effect is used to excite fluorophores in the focal plane of an objective using weakly scattered near-infrared light. This chapter focuses on the design of multiphoton microscopes and their applications in biology and medicine.
Photoacoustic Microscopy
Authors: Zhu Xiaoyi , Chen Maomao , Yao Junjie
Published: December 2021

Photoacoustic microscopy (PAM) is a hybrid in vivo imaging technique that acoustically detects optical contrast via the photoacoustic effect, a physical phenomenon that converts optical energy into acoustic energy. Unlike pure optical microscopic techniques, PAM takes advantage of the weak acoustic scattering in tissue and thus breaks through the optical diffusion limit (∼1 mm in soft tissue). With its excellent scalability, PAM can provide high-resolution images at desired maximum imaging depths up to a few millimeters. Compared with backscattering-based confocal microscopy and optical coherence tomography, PAM provides unique absorption contrast instead of scattering contrast. Furthermore, PAM can image more molecules, endogenous or exogenous, at their absorbing wavelengths than fluorescence-based methods, such as wide-field, confocal, and multiphoton microscopy. Most importantly, PAM can simultaneously image anatomical, functional, molecular, flow dynamic and metabolic contrasts in vivo. Focusing on state-of-the-art developments in PAM, this chapter discusses the key features of PAM implementations and their applications in biomedical studies. We introduce the fundamentals of PAM and highlight novel system designs. In particular, we compare the imaging speeds of different PAM systems and list several important areas where PAM has been increasingly applied in biomedical research.
Diffuse Optical Tomography
Authors: Mireles Miguel , Xu Edward , Ren Jingxuan , Ragunathan Rahul , Yuan Yaoshen , Choe Regine , Fang Qianqian
Published: December 2021

Diffuse optical tomography (DOT) has emerged over the past few decades as a non-invasive imaging tool to quantitatively assess deep tissue's functional and anatomical information. It has seen widespread use in various preclinical and clinical research fields, leading to a cumulative understanding of the technique and its potential applications. Over the years, the field of diffuse optics has encountered increasingly complex limitations, including ill-posedness, processing time, limited optodes density, etc., giving rise to novel and more sophisticated developments on the theoretical, algorithmic, computational, and instrumentation levels. In this chapter, we aim to present the theoretical basis of near-infrared diffuse optical tomography and diffuse correlation tomography. We introduce the state-of-the-art in computational and algorithmic perspectives, which seeks to improve the spatial resolution of reconstructed images while concurrently reducing the computational burden of solving high-dimensional inverse problems. We conclude by providing a survey of the most relevant applications of DOT currently undergoing clinical testing.
Local accumbens in vivo imaging during deep brain stimulation reveals a strategy-dependent amelioration of hedonic feeding
Authors: Wu Hemmings , Kakusa Bina , Neuner Sophie , Christoffel Daniel J. , Heifets Boris D. , Malenka Robert C. , Halpern Casey H.
Published: December 2021

Significance

Impulsive overeating is a common, disabling feature of eating disorders. Calcium imaging using fiber photometry has emerged as an in vivo methodology to measure neuronal population activity immune to electrical stimulation artifact from deep brain stimulation (DBS). Thus, when used simultaneously, calcium imaging can elucidate poorly understood DBS mechanisms. We show that nucleus accumbens D1 medial spiny calcium signaling increases in preparation of hedonic feeding of high-fat food. Further, responsive, over continuous, DBS strategies effectively disrupt this activity leading to decreased consumption. Implementation of this methodology to better understand mechanisms of these and other forms of neuromodulation for various indications may help advance the field to identify novel therapeutic targets with applications extending beyond obesity.
mTEC damage risks immune recovery
Authors: Takahama Yousuke
Published: December 2021

Whether autologous hematopoietic stem cell transplantation is free from graft-versus-host disease is controversial. Alawam et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20211239) now demonstrate that prolonged damage in thymic medullary epithelial cells causes the failure in self-tolerance in newly generated T cells and provokes post-transplant autoimmunity.
Material-separating regularizer for multi-energy x-ray tomography
Authors: Gondzio Jacek , Lassas Matti , Latva-Äijö Salla-Maaria , Siltanen Samuli , Zanetti Filippo
Published: December 2021

Dual-energy x-ray tomography is considered in a context where the target under imaging consists of two distinct materials. The materials are assumed to be possibly intertwined in space, but at any given location there is only one material present. Further, two x-ray energies are chosen so that there is a clear difference in the spectral dependence of the attenuation coefficients of the two materials. A novel regularizer is presented for the inverse problem of reconstructing separate tomographic images for the two materials. A combination of two things, (a) non-negativity constraint, and (b) penalty term containing the inner product between the two material images, promotes the presence of at most one material in a given pixel. A preconditioned interior point method is derived for the minimization of the regularization functional. Numerical tests with digital phantoms suggest that the new algorithm outperforms the baseline method, joint total variation regularization, in terms of correctly material-characterized pixels. While the method is tested only in a two-dimensional setting with two materials and two energies, the approach readily generalizes to three dimensions and more materials. The number of materials just needs to match the number of energies used in imaging.
Large magnetic anisotropy in Co–Fe–Ni–N ordered structures: a first-principles study
Authors: Islam Riyajul , Borah J P
Published: December 2021

Material design of promising rare-earth free permanent magnet requires tailoring and controlling the intrinsic magnetic properties namely large saturation magnetization μ
0
M
s, giant uniaxial magnetic anisotropy K
u, and high Curie temperature T
C. Based on first-principles electronic structure calculations, we present a detailed analysis for the intrinsic magnetic properties of Co
x
Fe1−x
Ni and Co
x
Fe1−x
NiN0.25 ordered structures. We predict an enhanced structural stability with improved K
u ranging from 1.53–2.29 MJ m−3 for Co
x
Fe1−x
NiN0.25 ordered structures, with the exception of CoNiN0.25 having planar anisotropy. Detailed analysis of the predicted large K
u, based on perturbation theory and electronic structure calculations, is attributed to the cumulative effect of contribution from the increased tetragonal distortion and induced orbital distortion from the simultaneous Co substitution and interstitial N-doping. By tailoring the K
u, we may create efficient and affordable PMs, bridging the gap between commonly used ferrite and high-performance Nd–Fe–B magnets.
Is TOL 1326–379 a Prototype of γ-Ray Emitting FR0 Radio Galaxy?
Authors: Fu Wen-Jing , Zhang Hai-Ming , Zhang Jin , Liang Yun-Feng , Yao Su , Liang En-Wei
Published: December 2021

With the possible spacial association to the Fermi/LAT source 3FGL J1330.0–3818, TOL 1326–379 may be the first one that is identified as a γ-ray emitting Fanaroff–Riley type 0 radio galaxy (FR0 RG). We analyze the ∼12 yr Fermi/LAT observation data of this γ-ray source and examine its association to TOL 1326–379. We show that the γ-ray source (named as J1331.0–3818) is tentatively detected with a TS value of 28.7, 3FGL J1330.0–3818 is out of the 95% containment of J1331.0–3818, and their positions are spatially separated ∼0.°2. 4FGL J1331.3–3818 falls into the 68% containment of J1331.0–3818, suggesting that our result agrees with that reported in the Fourth Fermi LAT Source Catalog. TOL 1326–379 is out of the 95% containment of J1331.0–3818, and their positions are spatially separated ∼0.°4, indicating that the association between J1331.0–3818 and TOL 1326–379 is quite ambiguous. However, we do not find other possible potential radio or X-ray counterpart within the circle centered at J1331.0–3818 with a radius of 0.°4. The spectral energy distribution (SED) of TOL 1326–379 shows a bimodal feature as seen in the γ-ray emitting RGs. We fit the SED with the one-zone leptonic model and find that the average energy spectrum of J1331.0–3818 agrees with the model prediction. Assuming that J1331.0–3818 is an unidentified γ-ray source, we derive the upper-limit of the γ-ray flux for TOL 1326–379. It is not tight enough to exclude this possibility with the SED modeling. Based on these results, we cautiously argue that the γ-ray source J1331.0–3818 is associated with TOL 1326–379 and its jet radiation physic is similar to those γ-ray emitting RGs.
Experimental Research of Static Characteristics of Microfluidic Trigger
Authors: Balabanov A V , Kasimov A M , Popov A I
Published: December 2021

Experimental research of the main static characteristics of the microfluidic trigger of the 100-micrometer feature size is carried out. In order to research the trigger, the experimental (physical) model has been especially made. As the main result of the research, the transfer and flow-rate characteristics of the trigger are obtained in relation to the two connection schemes: 1) the relay scheme with the two-input control, 2) the comparator scheme with the control at a first input and with a reference setpoint at a second input.
Dependence of the energy efficiency of the acousto-optic modulator of terahertz radiation on the dimensions of the ultrasound transducer
Authors: Nikitin P A , Nikitin A K
Published: December 2021

The paper presents results of experimental investigation of an acousto-optic modulator of terahertz radiation based on liquefied sulfur hexafluoride. It was found that the intensity of diffracted radiation at a fixed ultrasound power depends on the dimensions of the ultrasound transducer. The optimal size of the ultrasound transducer in the direction orthogonal to the plane of the acousto-optic interaction was determined, at which the maximum energy efficiency of the acousto-optic modulator was achieved.
Development of a methodology for migration of monolithic systems to microservice architecture using cloud technologies
Authors: Balzamov A V , Fomin D S , Savkina A V , Nikulin V V , Fedosin S A
Published: December 2021

The long-term use of the classical monolithic architecture for the development of web applications has led to the accumulation of a voluminous knowledge base for analyzing the positive and negative aspects, as well as finding ways to solve the problems that arise when using it at the present stage. Thanks to the rapid development of the computing power of personal computers, network data exchange mechanisms, cloud technologies and Open Source software, it has become possible to use more complex and efficient approaches to architecture design and deployment of web applications, such as a service-oriented, microservice model and deployment on a virtual machine or cloud. Due to the emergence of a large number of new technologies described above, it is quite difficult to apply them effectively enough without proper experience, as well as to switch to new models of architecture design.
Research and Modeling of Digital Antenna Arrays with Directional Elements on Azimuth-Elevation in VHF Terrain and Vegetation Multipath Propagation Situations
Authors: Nechaev Yu B , Peshkov I W , Fortunova N A , Zaitseva I N , Zhigulin V A
Published: December 2021

In the paper the problem of using digital antenna arrays equipped with dipole and directive elements simultaneously in the azimuthal and elevation planes is discussed. In particular, they are investigated for communication channels of the VHF range below 1 GHz. This range is characterized by the fact that it has found wide distribution. However, its application is fraught with many difficulties, such as attenuation, reflection from rough surfaces, etc. One of the solutions to these problems can be azimuth-elevation digital beamforming. The paper presents the simulation results for the propagation of signals in the VHF range in free space, two-ray ground-reflection and foliage models. It is assumed that a symmetrical dipole is used on the transmitting side, and a directional Yagi antenna on the receiving digital antenna array (DAA) also equipped with a dipole. The circular (CAA) and hemi-dodecahedron shapes of the arrangement of elements of the receiving digital antenna array are simulated. The bit error rates (BER) depending on the distance between the transmitter and the receiver are estimated for the three above mentioned cases.
Diagnostics of solid-state microwave modules at the initial stage of technological tests
Authors: Yu Kiryanov A
Published: December 2021

Process testing is an integral part of the production of solid-state microwave modules used in radar stations. At the final stage of production, long-term technological tests are carried out. However, at the initial stage of testing, it is possible to carry out diagnostics of solid-state microwave modules, which makes it possible to identify malfunctions leading to failures of solid-state microwave modules.
Predicting of cyber attacks on critical information infrastructure
Authors: Kosmacheva I M , Davidyuk N V , Belov SV , Kuchin Yu , Kvyatkovskaya I Yu , Rudenko M F , Lobeyko V I
Published: December 2021

According to modern statistics and analytical reviews, targeted computer attacks (cyber attacks) are becoming more and more numerous. Attackers began to use non-standard schemes for implementing attacks, using employees of organizations as intermediaries, which reduces the efficiency of detecting violations. At the same time, the targets of attackers are increasingly critical information infrastructure (CII) objects. The number of cyberattacks on the critical infrastructure of the Russian Federation increased by 150%. Successful attacks on CII are associated with a lack of software updates for industrial equipment, personnel errors, incorrect configuration of protection tools and can potentially lead to disasters. Prediction of computer attacks on CII based on a comprehensive analysis of the characteristics of incidents and system users can significantly increase the efficiency of incident detection, since it is obvious that technical and anthropogenic characteristics in this case should be taken into account together. It is difficult to classify computer incidents due to the volume and heterogeneity of the data about them. The paper proposes approaches that provide for the initial systematization of system log data and user characteristics, an assessment of their informativeness. This will reduce the complexity of further data processing and increase the performance of the computer attack forecasting system by excluding some uninformative data from a single secure storage. The second important task is to create test systems based on available platforms for analyzing and detecting computer incidents in order to train future information security specialists in big data analysis technologies.