bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal quenching of lanthanide luminescence via charge transfer states in inorganic materials
Authors: Dorenbos Pieter
Published: December 2022

The thermal quenching data of 5d emission from Eu2+ and Ce3+ and 4f emission from Pr3+, Eu3+, and Tb3+ are shown to be consistent with vacuum referred binding energy schemes. The scheme construction parameters of 170 different compounds are provided.
Energy transfer from self-trapped excitons to rare earth ions in Cs2ZrCl6perovskite variants
Authors: Fang Chen , Yang Jiakai , Zhou Guojun , Zhang Zhichao , Mao Yingjie , Yun Xiangyan , Liu Libo , Xu Denghui , Li Xiong , Zhou Jun
Published: December 2022

A series of Tb3+-doped Cs2ZrCl6perovskite variants are designed based on energy transfer, and the relationships among intrinsic self-trapped excitons, sub-band gap defects and rare earth ions Tb3+were established.
The influence of high-order chromatin state in the regulation of stem cell fate
Authors: Chen Xinpeng , Lin Haiyan , Li Guohong
Published: December 2022

In eukaryotic cells, genomic DNA is hierarchically compacted by histones into chromatin, which is initially assembled by the nucleosome and further folded into orderly and flexible structures that include chromatin fiber, chromatin looping, topologically associated domains (TADs), chromosome compartments, and chromosome territories. These distinct structures and motifs build the three-dimensional (3D) genome architecture, which precisely controls spatial and temporal gene expression in the nucleus. Given that each type of cell is characterized by its own unique gene expression profile, the state of high-order chromatin plays an essential role in the cell fate decision. Accumulating evidence suggests that the plasticity of high-order chromatin is closely associated with stem cell fate. In this review, we summarize the biological roles of the state of high-order chromatin in embryogenesis, stem cell differentiation, the maintenance of stem cell identity, and somatic cell reprogramming. In addition, we highlight the roles of epigenetic factors and pioneer transcription factors (TFs) involved in regulating the state of high-order chromatin during the determination of stem cell fate and discuss how H3K9me3-heterochromatin restricts stem cell fate. In summary, we review the most recent progress in research on the regulatory functions of high-order chromatin dynamics in the determination and maintenance of stem cell fate.
Dynamical state of the globular clusters Rup 106 and IC 4499
Authors: Beccari G. , Cadelano M. , Dalessandro E.
Published: December 2022

The dynamical evolution of globular clusters is theoretically described by a series of well-known events typical of N-body systems. Still, the identification of observational signatures able to empirically describe the stage of dynamical evolution of a stellar system with a density typical of a globular cluster represents a challenge. In this paper, we study the dynamical age of the globular clusters Rup 106 and IC 4499. To this aim, we study the radial distribution of the blue straggler stars (BSSs) via the A+ parameter and of the slope of the main sequence mass function. Both tracers show that Rup 106 and IC 4499 are dynamically young clusters where dynamical friction has just started to segregate massive stars towards their respective centres. Furthermore, we observe that the BSSs are more centrally concentrated in both clusters than the reference population. Similarly, we find that in both cases the slope of the mass function significantly decreases as a function of the cluster-centric distance. This result provides additional support for the use of the radial distribution of the BSSs as a powerful and observationally convenient indicator of the cluster dynamical age.
Psychosoziale Aspekte im Leben mit autoinflammatorischen Erkrankungen im Kindes- und Jugendalter
Authors: Erbis Gabi
Published: December 2022

Bei den autoinflammatorischen Erkrankungen (AID) handelt es sich um seltene, genetische Erkrankungen. So verschieden wie die Krankheitsbilder selbst, so unterschiedlich sind die Auswirkungen auf den Alltag der Patient*innen und ihrer Familien. Durch ihre Unbekanntheit und die unspezifischen Symptome wie Erschöpfung und Schmerzen dauert es häufig sehr lange bis eine Diagnose gestellt werden kann. Fehldiagnosen sind häufig. Oftmals werden psychische Ursachen vermutet. Besonders eingreifend können die Konsequenzen für das soziale Leben der Familien und für die Schullaufbahn der Patient*innen sein. Durch eine multiprofessionelle Versorgung kann die gesamte Lebenssituation der Patient*innen und ihrer Familien berücksichtigt und in die Behandlung einbezogen werden.
2,6-Disubstituted Piperidine Alkaloids with Neuroprotective Activity from Hippobroma longiflora
Authors: Chen Shu-Rong , Chen Yih-Fung , Lin Jue-Jun , Ke Tzu-Yi , Lin Yun-Sheng , Cheng Yuan-Bin
Published: December 2022

Three new alkaloids, hipporidine A (1), hipporidine B (2), and (−)-lobeline N-oxide (3), were discovered from the whole plant of Hippobroma longiflora
together with five known compounds (4–8). Their 2,6-disubstituted piperidine structures were established based on the HRESIMS, NMR (COSY, HMBC, HSQC, NOESY), and UV
spectroscopic data. Hipporidines A (1) and B (2) possess a rare 1,3-oxazinane moiety. Compound 3 is the N-oxide derivative of (−)-lobeline (6). Moreover,
the absolute configuration of norlobeline (5) was established by single-crystal X-ray diffraction analysis. Three major secondary metabolites (6–8) were evaluated for
their neuroprotective effect against paclitaxel-induced neurotoxicity. Consequently, pretreatment with compound 8 at a concentration of 1.0 µM displayed significant attenuation on
paclitaxel-damaged neurite outgrowth of dorsal root ganglion neurons without interfering with the cytotoxicity of paclitaxel on cervical cancer SiHa cells.
Effekte eines Beweglichkeits- und Krafttrainings auf die
schmerzbedingten Beschwerden bei Brustkrebspatientinnen
Authors: Michels Dominique , Heckel Alexandra , König Stefan
Published: December 2022

Ziel Ziel dieser Studie war, Wirkungen eines Beweglichkeitstrainings an
FIVE®-Geräten in Kombination mit
gerätegestützten Kraftübungen auf die schmerzbedingten
Beschwerden bei Brustkrebspatientinnen in der Rehabilitation zu analysieren.

Methoden Durchgeführt wurde eine
Prätest-Posttest-Interventionsstudie mit Brustkrebspatientinnen
(n=41), die während ihrer stationären
Anschlussheilbehandlung in einer Rehabilitationsklinik in Bad Waldsee zwischen
Februar und März 2020 in zwei Gruppen randomisiert wurden. Im Rahmen der
medizinischen Trainingstherapie führte die Interventionsgruppe
(n=24) ein Beweglichkeitstraining an den
FIVE®-Geräten in Kombination mit
gerätegestütztem Krafttraining durch, während die
Kontrollgruppe (n=17) ein gerätegestütztes Krafttraining
absolvierte. Vor und nach der dreiwöchigen Intervention (3
Trainingseinheiten/Woche) wurden die Beweglichkeit der Schulter und die
isokinetische Maximalkraft gemessen sowie die schmerzbedingten Beschwerden
anhand einer selbstentwickelten Schmerzskala abgefragt.

Ergebnisse Alle Patientinnen erreichten verbesserte Schmerzwerte mit
Ausnahme der Kategorie 1 (Selbstversorgung/Körperpflege) in der
Interventionsgruppe. Eine Prüfung der statistischen Unterschiede
zwischen den Messzeitpunkten 1 und 2 ergab, dass bei der Kontrollgruppe keine
statistisch signifikanten Verbesserungen bei der Schmerzwahrnehmung beobachtet
werden können; demgegenüber zeigte die Experimentalgruppe
zumindest beim Konstrukt „Arbeitsfähigkeit“ statistisch
signifikante Verbesserungen. Die Berechnung der Effektgrößen r
bzw. η2 machte allerdings auch bei einigen statistisch nicht
signifikanten Veränderungen deutlich, dass mittlere bis große
Effekte hinsichtlich einer geringeren Schmerzwahrnehmung vorlagen.

Schlussfolgerung Sowohl ein kombiniertes Kraft- und Beweglichkeitstraining
an FIVE®-Geräten als auch ein ausschließlich
gerätegestütztes Krafttraining kann bei
Mammakarzinom-Patientinnen in der Phase der Rehabilitation empfohlen werden.
Der Nutzen von Cannabis in der Krebstherapie
Authors: Grotenhermen Franjo
Published: December 2022

Cannabis und Cannabinoide können bei der Palliation einer Anzahl von
krebsassoziierten Symptomen hilfreich sein, darunter Appetitlosigkeit mit
Gewichtsverlust, Übelkeit und Erbrechen, Schmerzen,
Schlafstörungen und Depressionen. Einige dieser Indikationen gelten
heute als etabliert. In der Grundlagenforschung wurde darüber hinaus
nachgewiesen, dass eine Anzahl von Cannabinoiden, darunter THC (Dronabinol) und
CBD (Cannabidiol), krebshemmende Eigenschaften besitzen. Es gibt Belege
für eine Anzahl von Wirkmechanismen, darunter die Hemmung der
Tumorzellproliferation, die Auslösung von Apoptosen und Autophagie, die
Hemmung der Tumorinvasion und der Bildung von Metastasen, der Angioneogenese und
der Chemoresistenz. Cannabinoide könnten auch vor einigen
zytostatikabedingten Schäden schützen, darunter vor der
Entwicklung einer peripheren Neuropathie. Allerdings wurden in einzelnen
Untersuchungen auch krebsfördernde Eigenschaften von Cannabinoiden
beobachtet. Die klinische Datenlage ist bisher sehr limitiert. Es gibt
eindrucksvolle Fallberichte über eine erfolgreiche Krebstherapie mit CBD
und THC sowie einige epidemiologische Studien und wenige klinische Daten, die
ein therapeutisches Potenzial von cannabisbasierten Medikamenten
unterstützen.
Die Rostocker Methode zur qualitativen und quantitativen Bewertung von Intraokularlinsen
Authors: Elsner Ricardo , Sievers Jan , Kunert Martin , Reiss Stefan , Bohn Sebastian , Schünemann Melanie , Stolz Heinrich , Guthoff Rudolf , Stachs Oliver , Sperlich Karsten
Published: December 2022

Hintergrund Zur quantitativen und qualitativen Bewertung der Abbildungseigenschaften von IOLs können mittels einer optischen Bank axiale Querschnittsbilder aus der 3-dimensionalen
Lichtverteilung erstellt werden, wie sie von Lichtblattaufnahmen in Fluoresceinbädern bekannt sind. In dieser Arbeit wird ein neuer Bildverarbeitungsalgorithmus zur Verbesserung der Qualität
solcher generierten axialen Querschnittsbilder vorgestellt und beide Methoden werden miteinander verglichen.

Material und Methoden Die 3-dimensionale Punktspreizfunktion einer diffraktiven trifokalen IOL (AT LISA tri 839MP, Carl Zeiss Meditec AG, Jena, Deutschland) wurde an einer in Rostock
entwickelten optischen Bank für unterschiedliche Pupillendurchmesser aufgenommen. Anschließend wurde ein speziell angepasster Bildverarbeitungsalgorithmus auf die Messungen angewandt, der
die Generierung von Durchfokuskurven erlaubt. Zusätzlich wurden Querschnittsbilder der untersuchten IOL unter Verwendung der Lichtblattmethode in einem Fluoresceinbad aufgenommen.

Ergebnisse Die Studie zeigt deutlich die Überlegenheit der neu entwickelten Methode in Bezug auf die Bildqualität gegenüber der Lichtblattmethode. Neben den einzelnen Fokuspunkten
können in den Querschnittsbildern der neuen Methode sowohl feine Fokusstrukturen als auch Halos sichtbar gemacht werden. In den generierten Durchfokuskurven lassen sich 3 Intensitätsspitzen
erkennen, die den Nah-, Intermediär- und Fernfokus der getesteten MIOL darstellen und mittels Lichtblattmethoden nicht darstellbar sind.

Schlussfolgerung Das Zusammenspiel der optischen Bank mit dem entwickelten Bildverarbeitungsalgorithmus ermöglicht ein detaillierteres Verständnis der Bildentstehung und
Falschlichterscheinungen von IOLs, was mit der bisherigen Lichtblattmethode aufgrund technischer Beschränkungen nur begrenzt möglich war. Darüber hinaus lassen sich weitere Größen wie z. B.
die Durchfokuskurve quantitativ ableiten.
Psychische Gesundheit von Kindern und Jugendlichen mit chronisch entzündlichen Darmerkrankungen
Authors: Lenhartz Henning
Published: December 2022

Kinder und Jugendliche mit chronisch entzündlichen Darmerkrankungen gehören durch Schmerzen und schambesetzte Symptome (Diarrhö, Blut im Stuhl, Meteorismus) ihrer Magen-Darm-Erkrankung zu einer besonderen Risikogruppe in Bezug auf eine Einschränkung der (gesundheitsbezogenen) Lebensqualität und eine psychische Komorbidität. Es besteht ein komplexes System an Wechselwirkungen zwischen Krankheitsaktivität (hier insbesondere Schmerz), psychischen Störungen wie Depression, Ängstlichkeit und Anpassungsstörungen, Lebensqualität und Resilienz. Dieses sollte bei Routinekontrollen allgemein, aber insbesondere auch bei Diskordanz zwischen Krankheitsaktivität und Lebensqualität erfasst und behandelt werden.
Scattering by a low-velocity charge with applied magnetic fields in a Laguerre–Gaussian beam
Authors: Zhang Simin , Li Haiying , He JinChong , Wu Songyang , Xu Bin , Bai Lu
Published: December 2022

A method to analyze the scattering characteristics of a Laguerre–Gaussian (LG) vortex beam by a low-velocity charge in a steady applied magnetic field is investigated in this paper. Based on the plane wave angular spectrum representation and the electromagnetic radiation theory of a moving charge, the expressions of the scattered field and scattered power per unit solid angle are presented. Considering a low-velocity electron, the distribution of the scattered power per unit solid angle is numerically simulated. The effects of electron motion parameters, beam parameters, and applied magnetic field are discussed in detail. The results show that the longitudinal motion of the electron, which is parallel to the direction of the applied magnetic field, makes the distribution of the scattered power no longer maintain radial consistency but has a concave–convex distribution. Due to the periodicity of the circular motion of the electron in the applied magnetic field, the scattering power distribution pattern consists of many annular lobes. The spectral characteristics of the backscattered field are analyzed by fast Fourier transform. It is confirmed that the scattered field satisfies the rotational and the linear Doppler effects, and the accuracy of the formula provided in this paper is verified. This work lays a foundation for further study of the scattering characteristics of plasma on vortex electromagnetic waves and helps to promote the in-depth development of vortex beams in the field of plasma diagnosis.
Rising dynamics of bubbles generated by femtosecond laser filamentation in water
Authors: Zhang He , Chang Mingying , Liu Fan , Li Suyu , Jin Mingxing
Published: December 2022

Rising dynamics of bubbles generated by a femtosecond filament in water is monitored. Temporal evolution of the bubbles in the rising process is studied: the volume and rising velocity of the bubbles decrease. By increasing the incident pulse energy, the volume and rising velocity of the bubbles increase accordingly (lower than 200 μJ), while they stay nearly constant when further increasing the pulse energy (higher than 200 μJ), which can be attributed to the fact that the shape instability limits the size of the bubbles. The shape instability of bubbles leads to splitting of the bubbles: when the pulse energy is lower (1.6–26 μJ), the bubble may split into two smaller ones with comparable size; when the pulse energy is higher (26–600 μJ), a bigger bubble is generated, accompanied by smaller bubbles. The observed phenomena are analyzed via the relationship between femtosecond laser filamenation and evolution of bubbles. We hope this work can provide an approach to access the ultrafast plasma evolution in water through a long time evolution process (e.g., a rising process of bubbles).
Effects of thermal instability on density limit disruption in J-TEXT
Authors: Yuan J. J. , Jiang Z. H. , Liang Y. , Jiao Z. X. , Li Z. , Hua J. K. , Gao L. , Chen Z. Y. , Ding Y. H. ,   J-TEXT Team
Published: December 2022

As an important precursor of density limit disruption, thermal instability under J-TEXT high-density discharges is studied in this paper. An extended MHD code called NIMROD [Sovinec et al.,  J. Comput. Phys. 195, 355 (2004)] is used to explore the intrinsic relationship between density limit disruption and thermal instability. The experimental and simulation results show that radiation from the boundary impurity can cause thermal instability and impurity radiation increases rapidly when the plasma temperature decreases to the nonlinear range of carbon cooling rates, which cools down the plasma and enhances impurity radiation. Further investigations show that the local reduction in thermal instability at the plasma edge shrinks the local current channel and increases the internal current density gradient, which triggers the 2/1 mode and destabilizes the 3/1 and other higher-order modes. Finally, a rapid increase in the MHD instability can cause density limit disruption.
Fractional dynamic analysis and optimal control problem for an SEIQR model on complex networks
Authors: Fu Xinjie , Wang JinRong
Published: December 2022

A fractional order susceptible–exposed–infected–quarantined–recovered model is established on the complex networks. We calculate a specific expression for the basic reproduction number R0, prove the existence and uniqueness with respect to the solution, and prove the Ulam–Hyers stability of the model. Using the Latin hypercube sampling-partial rank correlation coefficient method, the influence of parameters on the R0 is analyzed. Based on the results of the analysis, the optimal control of the model is investigated as the control variables with vaccination rate and quarantine rate applying Pontryagin’s minimum principle. The effects of α, degree of nodes, and network size on the model dynamics are simulated separately by the prediction correction method.
Control of internal transport barriers in magnetically confined tokamak burning plasmas
Authors: Panta S. R. , Newman D. E. , Terry P. W. , Sanchez R.
Published: December 2022

The initiation, termination, and control of internal transport barriers associated with E × B flow shear near local minima of magnetic shear are examined for burning plasmas to determine if the positive feedback loops between profiles, instability, transport, and flow shear operate in regimes with fusion self-heating. A five-field transport model for the evolution of profiles of density, ion and electron temperature, ion and electron fluctuations, and radial electric field is utilized to examine the efficacy of controls associated with external inputs of heat and particles, including neutral beam injection, RF, pellets, and gas puffing. The response of the plasma to these inputs is studied in the presence of self-heating. The latter is affected by the external inputs and their modification of profiles and is, therefore, not an external control. Provided sufficient external power is applied, internal transport barriers can be created and controlled, both in ion and electron channels. Barrier control is sensitive to the locations of power deposition and pellet ablation, as well as temporal sequencing of external inputs.
Optical reading of multistate nonvolatile oxide memories based on the switchable ferroelectric photovoltaic effect
Authors: Zing A. , Matzen S. , Rani K. , Maroutian T. , Agnus G. , Lecoeur P.
Published: December 2022

Intensive research into functional oxides has been triggered by the quest for a solid-state universal memory with high-storage density, non-volatility, high read/write speed, and random access. The ferroelectric random-access memory (FeRAM), in which the information is stored in the spontaneous ferroelectric polarization of the material, offers great promise as nonvolatile and multistate memory, but its destructive electrical reading step requires a rewrite step after each reading, increasing energy consumption. As an alternative, optical nondestructive readout is based on the ferroelectric polarization dependence of the photovoltaic response in materials and has been reported in two-states ferroelectric memories and multistate devices with limited photocurrent switchability due to asymmetric interfacial effects. In this work, we report a nonvolatile oxide memory device based on a symmetric heterostructure with eight stable and well-controlled remanent polarization (Pr) states, written electrically by voltage pulse and read optically through polarization-dependent short-circuit photocurrent Isc or open circuit photovoltage Voc. This symmetric capacitor demonstrates a clear proportionality between Isc (Voc) and Pr, allowing to achieve a 100% switchability of the photovoltaic response. The memory devices based on 3-bit data storage show good performance in terms of data retention, fatigue behavior, and repeatability of writing and reading cycles. Thanks to the very high sensitivity of the optical reading method, the number of states could largely exceed eight, being limited only by the electrical writing step precision. These results are particularly exciting for the development of next-generation ferroelectric memory devices with increased memory storage density and lower power consumption.
Classification of hyperchaotic, chaotic, and regular signals using single nonlinear node delay-based reservoir computers
Authors: Wenkack Liedji Dagobert , Talla Mbé Jimmi Hervé , Kenne Godpromesse
Published: December 2022

The Lyapunov exponent method is generally used for classifying hyperchaotic, chaotic, and regular dynamics based on the equations modeling the system. However, several systems do not benefit from appropriate modeling underlying their dynamic behaviors. Therefore, having methods for classifying hyperchaotic, chaotic, and regular dynamics using only the observational data generated either by the theoretical or the experimental systems is crucial. In this paper, we use single nonlinear node delay-based reservoir computers to separate hyperchaotic, chaotic, and regular dynamics. We show that their classification capabilities are robust with an accuracy of up to 99.61% and 99.03% using the Mackey–Glass and the optoelectronic oscillator delay-based reservoir computers, respectively. Moreover, we demonstrate that the reservoir computers trained with the two-dimensional Hénon-logistic map can classify the dynamical state of another system (for instance, the two-dimensional sine-logistic modulation map). Our solution extends the state-of-the-art machine learning and deep learning approaches for chaos detection by introducing the detection of hyperchaotic signals.
Step pinning and hillock formation in (Al,Ga)N films on native AlN substrates
Authors: Schulz T. , Yoo S.-H. , Lymperakis L. , Richter C. , Zatterin E. , Lachowski A. , Hartmann C. , Foronda H. M. , Brandl C. , Lugauer H. J. , Hoffmann M. P. , Albrecht M.
Published: December 2022

The influence of edge-type threading dislocations (TDs) on the epitaxial growth of AlGaN on native AlN substrates was investigated theoretically and experimentally. In the step flow growth regime, we find that pure edge-type TDs cause a pinning of surface steps, resulting in curved step segments. Theoretical calculations reveal that this pinning mechanism is solely mediated by the altered surface potential due the strain field imposed by the TD. Within the curved step segment, the step width is subject to changes resulting in an altered Ga/Al incorporation rate. According to the density functional theory calculation, this effect is related to the different surface diffusion length of Ga and Al and represents a further destabilization mechanism during step flow growth. Another consequence of surface step pinning is the occurrence of areas where the step width is increased. These areas serve as precursors for 2D nucleation due to an increased adatom density. Once nucleated, these nuclei grow along the c-direction via continuous 2D nucleation, while lateral expansion occurs due to adatom incorporation on the m-facets.
Ultrasonic delamination based adhesion testing for high-throughput assembly of van der Waals heterostructures
Authors: Peña Tara , Holt Jewel , Sewaket Arfan , Wu Stephen M.
Published: December 2022

Two-dimensional (2D) materials assembled into van der Waals (vdW) heterostructures contain unlimited combinations of mechanical, optical, and electrical properties that can be harnessed for potential device applications. Critically, these structures require control over interfacial adhesion for enabling their construction and have enough integrity to survive industrial fabrication processes upon their integration. Here, we promptly determine the adhesion quality of various exfoliated 2D materials on conventional SiO2/Si substrates using ultrasonic delamination threshold testing. This test allows us to quickly infer relative substrate adhesion based on the percent area of 2D flakes that survive a fixed time in an ultrasonic bath, allowing for control over process parameters that yield high or poor adhesion. We leverage this control of adhesion to optimize the vdW heterostructure assembly process, where we show that samples with high or low substrate adhesion relative to each other can be used selectively to construct high-throughput vdW stacks. Instead of tuning the adhesion of polymer stamps to 2D materials with constant 2D-substrate adhesion, we tune the 2D-substrate adhesion with constant stamp adhesion to 2D materials. The polymer stamps may be reused without any polymer melting steps, thus avoiding high temperatures (<120 °C) and allowing for high-throughput production. We show that this procedure can be used to create high-quality 2D twisted bilayer graphene on SiO2/Si, characterized with atomic force microscopy and Raman spectroscopic mapping, as well as low-angle twisted bilayer WSe2 on h-BN/SiO2/Si, where we show direct real-space visualization of moiré reconstruction with tilt-angle dependent scanning electron microscopy.
Semi-analytical modeling of large area field emitters having non-identical pins
Authors: Rudra Rashbihari , Biswas Debabrata
Published: December 2022

The Line Charge Model (LCM) is an excellent analytical tool to model vertically aligned nano-tips in large area field emitters (LAFE). The linear line charge model is exact for isolated hemi-ellipsoidal nano-tips placed in a uniform external electric field. It has recently been used to model a LAFE with randomly placed identical emitters. The results are accurate when the mean spacing c is moderate to large compared to the emitter height h. In a closely packed LAFE (c⪅0.75h), the LCM underpredicts the apex enhancement factor. We introduce a heuristic correction in the LCM result that yields a better accuracy in predicting the apex enhancement factor over a wider range of mean spacing. The corrected LCM model is then used to simulate emitter shapes having a distribution in the height of emitters and apex radius of curvature Ra. A hybrid approach is adopted for non-ellipsoidal shapes where the line charge density is nonlinear and, hence, harder to implement. Predictions for the apex enhancement factor and the net emission current are found to be reasonably accurate for a LAFE with a wide variation in h and Ra values.
Particle field deconvolution multiplicative algebraic reconstruction technique for tomographic particle image velocimetry reconstruction
Authors: Zhang Zhiyuan , Yang Hua , Huang Yongan , Yin Zhouping , Shan Feng
Published: December 2022

Precision tomographic reconstruction is critical for obtaining high-accuracy velocity measurements in tomographic particle image velocimetry. Traditional tomographic reconstruction methods, such as the multiplicative algebraic reconstruction technique (MART), can only be applied at low particle concentrations, limiting the spatial resolution of velocity measurements. In addition, the actual shape of the particles is not reconstructed well due to the limited views. In this study, we propose a novel method named particle field deconvolution MART (Deconv-MART) to repair the shape of actual particles while suppressing ghost particles reconstructed by MART iterations. This method first uses the Gaussian particle shape prior to estimate the convolution kernel obtained by MART reconstruction. Then, the estimated kernel is utilized to deconvolute the particle field and suppress ghost particles based on the prior information of the lower intensity of ghost particles as well as the sparsity of the particle field. Reconstruction fields are estimated with numerical and real experiments, and the results are compared with the results of advanced reconstruction methods. Comparisons of reconstruction demonstrate that the proposed method is effective at suppressing ghost particles and restoring the shape of actual particles. Comparisons of velocity measurements reveal that Deconv-MART has good performance and high measurement accuracy.
Extreme events in a complex network: Interplay between degree distribution and repulsive interaction
Authors: Ray Arnob , Bröhl Timo , Mishra Arindam , Ghosh Subrata , Ghosh Dibakar , Kapitaniak Tomasz , Dana Syamal K. , Hens Chittaranjan
Published: December 2022

The role of topological heterogeneity in the origin of extreme events in a network is investigated here. The dynamics of the oscillators associated with the nodes are assumed to be identical and influenced by mean-field repulsive interactions. An interplay of topological heterogeneity and the repulsive interaction between the dynamical units of the network triggers extreme events in the nodes when each node succumbs to such events for discretely different ranges of repulsive coupling. A high degree node is vulnerable to weaker repulsive interactions, while a low degree node is susceptible to stronger interactions. As a result, the formation of extreme events changes position with increasing strength of repulsive interaction from high to low degree nodes. Extreme events at any node are identified with the appearance of occasional large-amplitude events (amplitude of the temporal dynamics) that are larger than a threshold height and rare in occurrence, which we confirm by estimating the probability distribution of all events. Extreme events appear at any oscillator near the boundary of transition from rotation to libration at a critical value of the repulsive coupling strength. To explore the phenomenon, a paradigmatic second-order phase model is used to represent the dynamics of the oscillator associated with each node. We make an annealed network approximation to reduce our original model and, thereby, confirm the dual role of the repulsive interaction and the degree of a node in the origin of extreme events in any oscillator associated with a node.
Numerical investigation of synthetic jets generated by various signals in quiescent ambient
Authors: Lu Yiran , Wang Jinjun
Published: December 2022

Synthetic jets generated by four typical and two novel exciting signals are simulated in the present study. Vortex structures and velocity characteristics are analyzed in detail to evaluate the effectiveness of the exciting signal. The synthetic jets excited with the four typical signals, i.e., the triangle signal, sinusoidal signal, trapezoid signal, and square signal, are simulated in the first place. It is found that stronger synthetic jets and higher entrainment can be realized by signals with higher peak velocity. Among the typical signals, the most satisfactory performance is observed in the case of the triangle signal. Two novel signals, i.e., the bi-frequency signal and the signal with varying duty cycle k, are subsequently simulated. The numerical result shows that, even with the same peak velocity, the two novel signals have better performance than the triangle signal. The optimal result is achieved in the case of the varying k signal. The signal momentum msignal is used to fundamentally explain the mechanism behind the different performances of the synthetic jets generated with different signals with the same characteristic velocity. The parameter, i.e., characteristic momentum Msignal, is subsequently utilized to represent the performances of the different signals. The synthetic jets generated with the signals of higher characteristic momentum are found to manifest better performance under the condition of the same frequency and characteristic velocity.
Transient dynamics of pressure-driven encroachment in narrow conduits with rate-dependent body force
Authors: Azese Martin Ndi , Nsoga Valjacques Nyemb , Mvondo Barbare J. Avouna , Makinde Oluwole Daniel , Batjom Gilbert Batjom , Kouaji Hollandine Sami
Published: December 2022

We analytically explore the flow of a Newtonian liquid forced to encroach a narrow tube of uniform cross section, by an unsteady pressure gradient, assisted by an encroachment-rate dependent external force. This novel problem is thought to have interesting implications. For instance in medicine where narrow tubes like syringes and needles are typically used to administer medication and in the printing industry. Using an unsteady eigenfunction expansion, the velocity distribution is accurately defined to yield unsteady profiles, contrasting with the classical Poiseuille parabola. We subsequently used our unsteady spectral decomposition to properly capture the kinematics and dynamics hidden in the models. By a detailed comparison between rectangular and circular channels, we show that such model ducts yield interesting similarities that can inform the choices of channels. Moreover, we obtain short and long-time dynamic behaviors, captured using a robust perturbation scheme that elegantly highlights the early and long-time characteristics. In the end, we present plots for encroachment depth and rate and the early and long-term asymptotic approximations and appropriately their graphical trends.
Offset parameter cancellation produces countless coexisting attractors
Authors: Li Chunbiao , Lei Tengfei , Liu Zuohua
Published: December 2022

The average value of a system variable determines the position of its attractor. When the offset parameters come together and get disappeared after an algebraic operation, the location of the attractor is then governed by an initial condition only. In this case, parameter-dominated offset control turns out to be the initial condition-defined coexisting attractors. In this Letter, a special mechanism for generating countless coexisting attractors is disclosed. Furthermore, a new regime of multistability is revealed, which explains where and how countless coexisting attractors are born and arranged.
Strong effect of crystal structure on the proximity effect between a superconductor and monolayer of cobalt
Authors: Mougel Loic , Buhl Patrick M. , Li Qili , Müller Anika , Yang Hung-Hsiang , Verstraete Matthieu J. , Simon Pascal , Dupé Bertrand , Wulfhekel Wulf
Published: December 2022

We present an unexpectedly strong influence of the proximity effect between the bulk Ru(0001) superconductor and atomically thin layers of Co on the crystal structure of the latter. The Co monolayer grows in two different modifications, such as hcp stacking and a reconstructed ε-like phase. While hcp islands show a weak proximity effect on Co and a little suppression of superconductivity in the substrate next to it, the more complex ε-like stacking becomes almost fully superconducting. We explain the weak proximity effect between Ru and hcp Co and the rather abrupt jump of the superconducting order parameter by a low transparency of the interface. In contrast, the strong proximity effect without a jump of the order parameter in the ε-like phase indicates a highly transparent interface. This work highlights that the proximity effect between a superconductor and a normal metal strongly depends on the crystal structure of the interface, which allows to engineer the proximity effect in hybrid structures.
All-epitaxial Al/AlGaN/GaN low-barrier Schottky diodes
Authors: Vostokov N. V. , Drozdov M. N. , Kraev S. A. , Lobanov D. N. , Novikov A. V. , Yunin P. A.
Published: December 2022

All-epitaxial Al/AlxGa1−xN/GaN low-barrier Schottky diodes with different x compositions were fabricated in the single process of molecular-beam epitaxy. A decrease in the effective barrier height is achieved by polarization-induced δ-doping of the AlxGa1−xN/GaN heterojunction. At zero bias, the diodes have high values of ampere-watt sensitivity (7 A/W) with a low specific value of differential resistance (5 × 10−4 Ω⋅cm2) and retain non-linear properties when the resistance decreases to 10−4 Ω⋅cm2. The fundamental importance of the absence of impurities, oxides, and structural defects at the metal–semiconductor interface for effective control of the transport properties of diodes is demonstrated.
Air/water interfacial waves with a droplet at the tip of their crest
Authors: Nie B. C. , Guan X. , Vanden-Broeck J.-M. , Dias F.
Published: December 2022

In nature, it is common to observe water wave crests with a droplet at their tip. This fascinating configuration remains unexplained from the physical point of view. The present study explores such a unique local configuration numerically. Solitary waves that propagate at the interface between two layers of irrotational fluids are considered. Extending the work of Guan et al. [“A local model for the limiting configuration of interfacial solitary waves,” J. Fluid Mech. 921, A9 (2021)], the density ratio has been decreased to a very small value equal to 0.001, which is close to the air/water density ratio at sea level (0.0013). A highly accurate solution for the limiting configuration of solitary waves is obtained by solving the irrotational Euler equations using the boundary integral method and Newton's iterations. It is confirmed that the limiting configuration consisting of a droplet sitting on a crest with a 120° angle exists for very small density ratios. This limiting configuration obviously does not exist for surface waves with a void on the top, thus stressing the crucial role played by the air. The droplet is stationary in a frame of reference moving with the wave and experiences intense shear at its tip. From the energy point of view, the formation of a crest with a droplet is accompanied by a remarkable drop of kinetic and potential energies of water in the vicinity of the crest. Furthermore, we present a simple set of scaling relations for the fall of the droplet.
Numerical simulation of secondary breakup of shear-thinning droplets
Authors: Li Yang , Xu Zhikun , Peng Xiaoyun , Wang Tianyou , Che Zhizhao
Published: December 2022

The breakup of non-Newtonian droplets is ubiquitous in numerous applications. Although the non-Newtonian property can significantly change the droplet breakup process, most previous studies consider Newtonian droplets, and the effects of non-Newtonian properties on the breakup process are still unclear. This study focuses on the secondary breakup of shear-thinning droplets by numerical simulation. The volume of fluid method is used to capture interface dynamics on adaptive grids. To compare shear-thinning droplets and Newtonian droplets, a new definition of the Ohnesorge number is proposed by considering the characteristic shear rate in the droplet induced by the airflow. The results show that compared with the Newtonian fluid, the shear-thinning properties can change the apparent viscosity distribution inside the droplet, alter the local deformation, change the droplet morphology, and affect the transition in the droplet breakup regime.
Ecology, evolution, and conservation of Ethiopia’s biodiversity
Authors: Fashing Peter J. , Nguyen Nga , Demissew Sebsebe , Gizaw Abel , Atickem Anagaw , Mekonnen Addisu , Nurmi Niina O. , Kerby Jeffrey T. , Stenseth Nils Chr.
Published: December 2022

Ethiopia is home to one of the richest and most unique assemblages of fauna and flora on the African continent. Contained within its borders are two major centers of endemism, the mesic Roof of Africa (also known as the Ethiopian Highlands) and the arid Horn of Africa, resulting from the country’s varied topography and consequent geographic isolation. These centers of endemism are crucial to global conservation as evidenced by their classification within the Eastern Afromontane and Horn of Africa biodiversity hotspots, respectively. Ethiopia’s diverse ecosystems and the biodiversity they contain are increasingly threatened by climate change and the growing impacts of Africa’s second largest human and largest livestock populations. In this paper, we focus on several key areas of recent and ongoing research on Ethiopian biodiversity that have broadened our understanding of nature and its conservation in Africa. Topics explored include the behavioral ecology of Ethiopia’s large social mammals, the ecology and conservation of its unique coffee forests, and Ethiopian approaches to community conservation, fortress conservation, and nature-based solutions. We also highlight the increasing prominence of Ethiopian scientists in studies of the country’s biodiversity in recent decades. We suggest promising avenues for future research in evolutionary biology, ecology, systematics, and conservation in Ethiopia and discuss how recent and ongoing work in Ethiopia is helping us better understand and conserve nature in the human-dominated landscapes of Africa and other tropical regions today.
The BRCA1 BRCT promotes antisense RNA production and double-stranded RNA formation to suppress ribosomal R-loops
Authors: Chang Chou-Wei , Singh Anup Kumar , Li Min , Guan Li , Le Nhung , Omabe Kenneth , Liang Feng , Liu Yilun
Published: December 2022

R-loops, or RNA:DNA hybrids, can induce DNA damage, which requires DNA repair factors including breast cancer type 1 susceptibility protein (BRCA1) to restore genomic integrity. To date, several pathogenic mutations have been found within the tandem BRCA1 carboxyl-terminal (BRCT) domains that mediate BRCA1 interactions with proteins and DNA in response to DNA damage. Here, we describe a nonrepair role of BRCA1 BRCT in suppressing ribosomal R-loops via two mechanisms. Through its RNA binding and annealing activities, BRCA1 BRCT facilitates the formation of double-stranded RNA between ribosomal RNA (rRNA) and antisense-rRNA (as-rRNA), hereby minimizing rRNA hybridization to ribosomal DNA to form R-loops. BRCA1 BRCT also promotes RNA polymerase I-dependent transcription of as-rRNA to enhance double-stranded rRNA (ds-rRNA) formation. In addition, BRCA1 BRCT-mediated as-rRNA production restricts rRNA maturation in unperturbed cells. Hence, impairing as-rRNA transcription and ds-rRNA formation due to BRCA1 BRCT deficiency deregulates rRNA processing and increases ribosomal R-loops and DNA breaks. Our results link ribosomal biogenesis dysfunction to BRCA1-associated genomic instability.
以電影為素材進行跨校跨文化交際
Authors: Huang Tiao-Guan , Liu Liang Yin , Chen Yafen , Wang Zhuoyi
Published: December 2022

抽象的

本文旨在介紹一次以「生死觀」為主題的包含5C特徵的實驗性跨校交流活動。「死亡」是華人文化的禁忌之一，對面死亡的態度、與死亡相關的文化現象和產物…等，既有文化普遍性，也有文化獨特性，是值得中文學習者學習的文化內容。本文作者為CLTA中文電影教學興趣小組(2016年成立）成員，分別任教於美國三所大學，於2020年春季學期Covid-19疫情初起時，分別使用電影《別告訴她》（英文：The
Farewell）與《生生》（英文：Sen
Sen）於課堂上，繼而合作規劃一次跨校的文化交流活動。該交流活動基於差異化教學、近側發展區間、鷹架與可理解輸入理論而設計，利用數位工具進行非同步與同步跨校交流，交流結果既強化參與交流之學生的語言能力，亦深化其學習中文和中華文化的動機和興趣。
Multi-material inverse design of soft deformable bodies via functional optimization
Authors: Awasthi Chaitanya , Lamperski Andrew , Kowalewski Timothy M
Published: December 2022

Controlling the deformation of a soft body has potential applications in fields requiring precise control over the shape of the body. Areas such as medical robotics can use the shape control of soft robots to repair aneurysms in humans, deliver medicines within the body, among other applications. However, given known external loading, it is usually not possible to deform a soft body into arbitrary shapes if it is fabricated using only a single material. In this work, we propose a new physics-based method for the computational design of soft hyperelastic bodies to address this problem. The method takes as input an undeformed shape of a body, a specified external load, and a user desired final shape. It then solves an inverse problem in design using nonlinear optimization subject to physics constraints. The nonlinear program is solved using a gradient-based interior-point method. Analytical gradients are computed for efficiency. The method outputs fields of material properties which can be used to fabricate a soft body. A body fabricated to match this material field is expected to deform into a user-desired shape, given the same external loading input. Two regularizers are used to ascribe a priori characteristics of smoothness and contrast, respectively, to the spatial distribution of material fields. The performance of the method is tested on three example cases in silico.
Assessment of anisotropic transmembrane transport coefficient vector of cell-spheroid under inhomogeneous ion concentration distribution fields by electrical impedance tomography
Authors: Li Songshi , Kawashima Daisuke , Okeyo Kennedy Omondi , Murata Takeshi , Takei Masahiro
Published: December 2022

The assessment method of anisotropic transmembrane transport coefficient vector P of a cell-spheroid under inhomogeneous ion concentration fields has been proposed by combining electrical impedance tomography (EIT) with an ion transport model to evaluate the anisotropic transmembrane transport of ions. An element Pi
of P represents the transmembrane transport coefficient of the ith part of the cell membrane, which is assessed by the ion transport model from the average conductivity σ̃i
of the ith extracellular sector reconstructed by EIT. Anisotropic factor H obtained from Pi
is introduced, which represents the anisotropic transmembrane transport. To validate our methodology, the inhomogeneous ion concentration fields are generated by injecting two tonicity-different sucrose solutions (isotonic, hypotonic or hypertonic) from both sides of the cell-spheroid. As a result, the inhomogeneous ion concentration distribution due to the anisotropic transmembrane transport is successfully observed from the reconstructed image by EIT. The anisotropic factor H shows that H = 0.34 ± 0.24 in isotonic and hypertonic combination, H = 0.58 ± 0.15 in isotonic and hypotonic combination and H = 0.23 ± 0.06 in hypertonic and hypotonic combination, respectively. To verify the results obtained by our methodology, the fluorescence ratio F [-] of potassium ions around the cell-spheroid is observed under three combinations as same as the EIT measurement. F shows the anisotropic transmembrane transport with the same trend with the EIT results.
Multiscale modeling of extrinsic self healing GFRP materials
Authors: Tsivolas Eleftherios , Gergidis Leonidas N , Paipetis Alkiviadis S
Published: December 2022

In this study, a novel multiscale material model is proposed to simulate the elasto-plastic damage-healing behavior of an epoxy matrix in a composite material. This framework combines the non-linear mean field homogenization methodologies with the continuum damage-healing mechanics to achieve the healing process in a coupled manner along with the damage. The model is able to predict the time dependent healing effect combined with damage propagation. In the proposed multiscale model, the healing depends on the current damage of the matrix, the available time that the healing can evolve and the rate of healing. A parametric study with respect to the rate of healing and a time dependency analysis were performed to examine the sensitivity of the model. In addition, a microscale method to calculate the healing initiation and healing efficiency is proposed using a representative volume element of an epoxy matrix with healing microcapsules. The microscale simulation showed that with 7.5% volume fraction of microcapsules 40% of the structural integrity can be recovered.