bluuebunny/crossref_metadata_2025 huggingface dataset:
There is no shortage, but inequality: demographic evolution of neurologists in Brazil (2010–2020)
Authors: Santos-Lobato Bruno Lopes , Tomaselli Pedro José , Santos-Lobato Edienny Augusta Viana , Cassenote Alex Jones Flores , Cabeça Hideraldo Luis Souza
Published: March 2023

Background Neurology is a medical specialty that deals with prevalent diseases such as stroke, headache, epilepsy, and neurodegenerative diseases. Many countries, such as Brazil, struggle to provide neurological care for their populations, but the inadequacy and unequal distribution of the neurologist workforce are real challenges.

Objective To analyze the demographic evolution of neurologists and the first-year Neurology residency positions in Brazil during the last decade (2010–2020) and the distribution imbalance between regions.

Methods The demographic and geographic distribution of neurologists was calculated based on data extracted from the Brazilian Federal Medical Council reports, and the number of Neurology residency positions was based on the Brazilian National Commission of Medical Residency reports. Indicators of wealth were associated with demographic data.

Results The number of neurologists per 100,000 population has increased since 2011, with a similar increase in the geographic distribution of neurologists. However, there was a marked inequality of distribution of neurologists through regions, with a gap between the Northern (lowest) and Southeastern (highest) regions. Furthermore, the imbalance of distribution of neurologists strongly correlated with social inequality. The number of Neurology residency positions increased, but with an imbalance between North and Southeast regions.

Conclusions Brazil has advanced in providing neurologists. However, instead of a shortage, inequality between regions is the greatest challenge regarding the neurological workforce. The training of new neurologists is unequal between regions and occurs at a slower rate than needed. Neurologists, public health authorities, and patients should discuss solutions for these issues.
In-vitro Activity of Isepamicin against Gram-negative Bacteria in Comparison to Other Aminoglycosides Routinely used at a Teaching Hospital in Northern India
Authors: Siddiqui Tasneem , Kar Mitra , Dubey Akanksha , Patel Sangram Singh , Sahu Chinmoy
Published: March 2023

Background Isepamicin is a 1-N-S-a-hydroxy-b-aminopropionyl derivative of gentamicin B and the spectrum of pathogenic microorganisms covered by it and its effectiveness is similar to that of amikacin except the action of aminoglycoside inhibitor enzymes is ineffectual on it.

Material and Methods We performed a prospective study in the Bacteriology section of the Department of Microbiology at a 1,600-bedded hospital in Northern India from Jan 2022 to March 2022. Isepamicin was tested for susceptibility against gram-negative bacteria, identified by routine biochemicals and matrix-assisted-desorption/ionization –time of flight-mass spectrometry (MALDI-TOF-MS) assay. The antibiotic susceptibility testing for each of the isolates was performed by Kirby Bauer's disc diffusion method, according to the CLSI 2019 guidelines.

Results The majority of isolates were obtained from blood samples (50, 39.1%). Among the non-inducible Enterobacteriaceae, Escherichia coli was least susceptible to amikacin (8/27, 29.63%) and most susceptible to isepamicin (18/27, 66.67%). Klebsiella pneumoniae followed the same pattern of susceptibility as E. coli and was least susceptible to Amikacin (20/46, 43.48%) and most susceptible to isepamicin (24/46, 52.17%). Enterobacter cloacae (6/7, 85.71%) was most susceptible to both amikacin and isepamicin, followed by 71.43% (5/7, 71.43%) susceptibility to gentamicin and tobramycin each. Enterobacter aerogenes was equally 53.33% (8/15) susceptible to all antibiotics. Pseudomonas aeruginosa was the most susceptible isolate to all antibiotics (18/21, 85.71%).

Conclusion Isepamicin is a potential antimicrobial agent for treating an array of gram-negative bacteria-associated infections and shows better in vitro activity than older aminoglycoside agents.
Ion concentration assumptions break down in nanofluidic devices
Authors: Piccone Ashley
Published: March 2023

Narrow channels do not hold the same ion concentration as the larger reservoirs they connect.
Investigating the tip leakage vortex to improve performance of pumps and turbines
Authors: McConnon Aili
Published: March 2023

Research into pressure fluctuation caused by tip leakage vortex in axial flow circulating pumps
High-resolution phase-contrast X-ray imaging for biological soft tissue
Authors: Shapiro Maura
Published: March 2023

Minimizing the distance between sample and detector achieves high spatial resolution while maintaining high contrast of biological tissue.
Determining spectral response of the National Ignition Facility particle time of flight diagnostic to x rays
Authors: Reichelt B. , Kabadi N. , Pearcy J. , Gatu Johnson M. , Dannhoff S. , Lahmann B. , Frenje J. , Li C. K. , Sutcliffe G. , Kunimune J. , Petrasso R. , Sio H. , Moore A. , Mariscal E. , Hartouni E.
Published: March 2023

The Particle Time of Flight (PTOF) diagnostic is a chemical vapor deposition diamond detector used for measuring multiple nuclear bang times at the National Ignition Facility. Due to the non-trivial, polycrystalline structure of these detectors, individual characterization and measurement are required to interrogate the sensitivity and behavior of charge carriers. In this paper, a process is developed for determining the x-ray sensitivity of PTOF detectors and relating it to the intrinsic properties of the detector. We demonstrate that the diamond sample measured has a significant non-homogeneity in its properties, with the charge collection well described by a linear model ax + b, where a = 0.63 ± 0.16 V−1 mm−1 and b = 0.00 ± 0.04 V−1. We also use this method to confirm an electron to hole mobility ratio of 1.5 ± 1.0 and an effective bandgap of 1.8 eV rather than the theoretical 5.5 eV, leading to a large sensitivity increase.
Interaction of the high frequency waves in the vicinity of the ionospheric window
Authors: Borisov N.
Published: March 2023

It is well-known that an ordinary high frequency electromagnetic (EM) wave radiated into the ionosphere at the Spitze angle is totally transformed at the reflection height (z0) into the Z-mode. This mode, in turn, penetrates deeper into the ionosphere and it is reflected at some height (zref) usually significantly higher than the O-mode reflection height. This result is reconsidered in the present paper. It is argued that the wave appearing as a continuation of the propagating upward quasi-electrostatic wave changes the direction of motion along the vertical axis slightly above z0 and takes the form of the down-going wave. This wave is excited in the vicinity of the height z0 due to the phase resonance with the up-going O-mode wave which transforms into the Z-mode propagating upward. Thus, the ionospheric window is not totally transparent for the O-mode radiated at the Spitze angle. The up-going O-mode wave loses some part of its energy due to excitation of the down-going EM wave. This wave, in turn, propagates to the ground as the O-mode wave.
How to grow an oscillators’ network with enhanced synchronization
Authors: Park Jong-Min , Lee Daekyung , Kim Heetae
Published: March 2023

We study a way to set the natural frequency of a newly added oscillator in a growing network to enhance synchronization. Population growth is one of the typical features of many oscillator systems for which synchronization is required to perform their functions properly. Despite this significance, little has been known about synchronization in growing systems. We suggest effective growing schemes to enhance synchronization as the network grows under a predetermined rule. Specifically, we find that a method based on a link-wise order parameter outperforms that based on the conventional global order parameter. With simple solvable examples, we verify that the results coincide with intuitive expectations. The numerical results demonstrate that the approximate optimal values from the suggested method show a larger synchronization enhancement in comparison with other naïve strategies. The results also show that our proposed approach outperforms others over a wide range of coupling strengths.
On the complementarity of ordinal patterns-based entropy and time asymmetry metrics
Authors: Martínez Johann H. , Ramasco José J. , Zanin Massimiliano
Published: March 2023

Entropy and time asymmetry are two intertwined aspects of a system’s dynamics, with the production of entropy marking a clear direction in the temporal dimension. In the last few years, metrics to quantify both properties in time series have been designed around the same concept, i.e., the use of ordinal patterns. In spite of this, the relationship between these two families of metrics is yet not well understood. In this contribution, we study this problem by constructing an entropy–time asymmetry plane and evaluating it on a large set of synthetic and real-world time series. We show how the two metrics can at times behave independently, the main reason being the presence of patterns with turning points; due to this, they yield complementary information about the underlying systems, and they have different discriminating performance.
Measurement of current distribution using infrared thermography
Authors: Ren Chao , Bai Libing , Shi Ruilong , Zhang Jie , Zhang Xu , Chen Cong
Published: March 2023

Current distribution measurement methods are widely used in medical examinations, predicting faults in semiconductor devices and assessing structural integrity. Several methods for measuring current distribution are available, such as electrode arrays, coils, and magnetic sensors. However, these measurement methods are unable to obtain images of current distribution with high spatial resolution. Therefore, there is a need to develop a non-contact method to measure current distribution that is capable of capturing images with high spatial resolution. In this study, a non-contact current distribution measurement method based on infrared thermography is proposed. The method uses thermal variations to quantify the current amplitude and reconstructs the current direction based on the passivity of the electric field. For quantification of low frequency current amplitude, the experimental results show that the method can provide accurate current measurement results, for example, at the power frequency (50 Hz), in the range of 1.05–3.45 A, its relative error can be improved to ±3.66% when the calibration fitting method is used. For the high-frequency current, an effective estimate of the current amplitude is obtained using the first-order derivative of temperature variation. When applied to the eddy current detection (256 KHz), it achieves a high-resolution image of the current distribution, and the effectiveness of the method is verified through simulation experiments. The experimental results show that the proposed method not only measures the current amplitude accurately but also improves the spatial resolution in acquiring two-dimensional current distribution images.
Frequency modulations due to domain dynamics in terahertz quantum cascade lasers
Authors: Önder E. , Winge D. O. , Franckié M. , Forrer A. , Senica U. , Scalari G. , Wacker A.
Published: March 2023

The light output of quantum cascade lasers is strongly affected by electric field-domain oscillations if the laser shows electrical instabilities. This can result in a substantial broadening of the emission spectrum, which is investigated here by detailed simulations for a terahertz device. We explain how the light pulsation is affected by electrical injection conditions and external capacitances. Experimental data confirm that the oscillation frequencies are not essentially affected by circuit conditions, while a large external capacitance produces almost non-observable oscillations due to stabilization of the circuit.
Regularized Bennett and Zwanzig free energy estimators
Authors: Decherchi S. , Ciccotti G. , Cavalli A.
Published: March 2023

We consider the problem of free energy estimation from the general perspective of regularization and Bayes estimation theory. We try to take advantage of an assumed a priori knowledge of the free energy. We reformulate the original Bennett acceptance ratio method, in this perspective, devise a numerical algorithm to solve it, and give a closed formula to estimate the confidence in the prior. Finally, we test the derived estimators by applying them to a toy model.
Dynamics of inertial spheroids in a decaying Taylor–Green vortex flow
Authors: Jayaram Rohith , Jie Yucheng , Zhao Lihao , Andersson Helge I.
Published: March 2023

Inertial spheroids, prolates and oblates, are studied in a decaying Taylor–Green vortex (TGV) flow, wherein the flow gradually evolves from laminar anisotropic large-scale structures to turbulence-like isotropic Kolmogorov-type vortices. Along with particle clustering and its mechanisms, preferential rotation and alignment of the spheroids with the local fluid vorticity are examined. Particle inertia is classified by a nominal Stokes number St, which to first-order aims to eliminate the shape effect. The clustering varies with time and peaks when the physically relevant flow and particle time scales are of the same order. Low inertial (St<1) spheroids are subjected to the centrifuging mechanism, thereby residing in stronger strain-rate regions, while high inertial (St≫1) spheroids lag the flow evolution and modestly sample strain-rate regions. Contrary to the expectations, however, spheroids reside in high strain-rate regions when the particle and flow time scales are comparable due to the dynamic interactions between the particles and the evolving flow scales. Moderately inertial (St≤1) prolates preferentially spin and oblates tumble throughout the qualitatively different stages of the TGV flow. These preferential modes of rotation correlate with parallel and perpendicular alignments of prolate and oblate spheroids, respectively, with the local fluid vorticity. However, for high inertial spheroids preferential rotation and alignment are decorrelated due to a memory effect, i.e., inertial particles require longer time to adjust to the local fluid flow. This memory effect is not only due to high particle inertia, as in statistically steady turbulence, but also caused by the continuously evolving TGV flow scales.
Modeling of annular thermoelectric generator considering temperature-dependent material properties and side surface heat convection
Authors: Ju Chengjian , Xing Ziyu , Dui Guansuo , Wang Yajing , Zhang Lele
Published: March 2023

An annular thermoelectric generator (ATG) contributes to energy utilization in round structures. An accurate prediction of thermoelectric (TE) performance is key to the design of the ATG. By using the perturbation theory and the equivalent substitution of integrals method, an analytical model is proposed, which can easily deal with the nonlinear heat equation induced by temperature-dependent material properties. The TE performance of the ATG including the Thomson effect is studied by the proposed model, and the effect of structural parameters and operating conditions on the TE behavior is analyzed. The results indicate that if the Thomson effect is neglected, the predicted power output and efficiency will be much higher than the actual cases. Significantly, in both working conditions, the relative error of the predicted temperature field of the proposed model is less than 0.1%, far below the available theoretical models. In addition, the influence of side surface heat convection is also analyzed using a numerical method. Remarkably, the maximum power output may increase as the heat convection coefficient grows.
Nonlinear evolution of the Weibel instability with relativistic laser pulses
Authors: Kuramitsu Yasuhiro , Matsumoto Yosuke , Amano Takanobu
Published: March 2023

The Weibel instability is investigated using relativistic intense short laser pulses. A relativistic short laser pulse can generate a sub-relativistic high-density collisionless plasma. By irradiating double parallel planar targets with two relativistic laser pulses, sub-relativistic collisionless counterstreaming plasmas are created. Since the growth rate of the Weibel instability is proportional to the plasma density and velocity, the spatial and temporal scales of the Weibel instability can be much smaller than that from nanosecond large laser facilities. Recent theoretical and numerical studies have revealed that astrophysical collisionless shocks in sub-relativistic regimes in the absence and presence of an ambient magnetic field play essential roles in cosmic ray acceleration. With experimental verification in mind, we discuss the possible experimental models on the Weibel instability with intense short laser pulses. In order to show the experimental feasibility, we perform 2D particle-in-cell simulations in the absence of an external magnetic field as the first step and discuss the optimum conditions to realize the nonlinear evolutions of the Weibel instability in laboratories.
Photon emission spectrum of ion pumps
Authors: Kontos Antonios , Weiss Rainer
Published: March 2023

As the sensitivity of gravitational-wave detectors increases, new sources of noise appear. A potential source of noise may arise from charge accumulating on the mirrors of the experiment, the origin of which can be related to UV photons from the surroundings. In order to test one hypothesis, we measured the photon emission spectrum from a type of ion pump that is used in the experiment, an Agilent VacIon Plus 2500 l/s. We found that there is significant emission of UV photons above 5 eV, capable of knocking electrons off mirrors or surrounding surfaces and charging them. Photon emission measurements were taken as a function of gas pressure, ion-pump voltage setting, and type of pumped gas. The overall emission and shape of the measured photon spectrum are consistent with bremsstrahlung as the mechanism for the production of the photons.
Silver-decorated cobalt–molybdenum oxide nanosheets as a pH-universal electrocatalyst for high-efficiency hydrogen evolution reaction
Authors: Zhang Yue , Zhou Wenzhe , Du Shanzheng , Zhang Qi , Deng Lianwen , Gao Xiaohui , Ouyang Fangping
Published: March 2023

The high efficiency of hydrogen evolution reaction (HER) catalysts depends on their electronic structure, conductivity, and intrinsic catalytic activity. Transition-metal oxides (TMO) present a great potential to replace platinum-based catalysts, but further improvements in intrinsic catalytic activity are limited to the materials' conductivity. Herein, theoretical calculations disclosed that the adjusted density of states around the Fermi level caused by Ag introduction increased the conductivity of Co2Mo3O8-Ag, optimizing the water adsorption energy (ΔEad) and Gibbs free energy of hydrogen adsorption (ΔGH*). This can be rationalized through the synergistic effect between electron-rich Co and Mo sites in Co2Mo3O8-Ag. Inspired by this, Ag nanoparticles loaded on Co2Mo3O8 nanosheets (CMO-Ag) as a pH-universal HER catalyst were successfully constructed. As expected, the prepared CMO-Ag catalyst exhibited excellent HER activity with overpotentials of 55.5, 63.2, and 68.2 mV at a current density of 10 mA cm−2 in alkaline, neutral, and acidic electrolyte, respectively, superior to most reported results from molybdenum/cobalt-based electrocatalyst. Meanwhile, the CMO-Ag also presented exceptional stability with negligible change after 20 h of stability tests and 1000 cycles of CV measurements. This work provides a valuable strategy for optimizing catalytic activity sites and improving conductivity through combining metal nanoparticles and TMO, which can be applied for other TMO-based HER pH-universal catalyst.
Visualizing and comparing quantum interference in the π-system and σ-system of organic molecules
Authors: Cao Ning , Bro-Jørgensen William , Zheng Xiaohong , Solomon Gemma C.
Published: March 2023

Quantum interference effects in conjugated molecules have been well-explored, with benzene frequently invoked as a pedagogical example. These interference effects have been understood through a quantum interference map in which the electronic transmission is separated into interfering and non-interfering terms, with a focus on the π-orbitals for conjugated molecules. Recently, saturated molecules have also been reported to exhibit destructive quantum interference effects; however, the very different σ-orbital character in these molecules means that it is not clear how orbital contributions manifest. Herein, we demonstrate that the quantum interference effects in conjugated molecules are quite different from those observed in saturated molecules, as demonstrated by the quantum interference map. While destructive interference at the Fermi energy in the π-system of benzene arises from interference terms between paired occupied and virtual orbitals, this is not the case at the Fermi energy in saturated systems. Instead, destructive interference is evident when contributions from a larger number of non-paired orbitals cancel, leading to more subtle and varied manifestations of destructive interference in saturated systems.
Miniature fiber scanning probe for flexible forward-view photoacoustic endoscopy
Authors: Ke Di , Wang Li , Wang Erqi , Xin Haishu , Yang Sihua , Xiong Kedi
Published: March 2023

Forward-view photoacoustic (PA) endoscopy (PAE) is promising for achieving noninvasive biopsy in narrow areas of internal organs. However, current schemes that scan the proximal end of fiber bundles' core-by-cores would cause limited spatial sampling confined by the number of cores, which result in lower lateral resolution at smaller probe size. In this paper, a flexible forward-view PAE probe based on a resonant fiber scanner with a diameter of 5 mm was developed, which compactly integrated a piezoelectric (PZT) bender, a fiber cantilever, a lens, an ultrasound transducer, and a coupler inside. Phantom imaging was conducted to evaluate the performance of the flexible forward-view PAE, exhibiting a lateral resolution of 15.6 μm in a field-of-view of approximately 3 mm diameter and the imaging speed is 0.5 frames per second. In vivo imaging shows the clear vascular network of the rat gastrointestinal wall, which demonstrates the feasibility of resonant fiber scanners for photoacoustic endoscopic imaging, and indicates its potential for application as minimally invasive tools in the clinical evaluation of gastrointestinal lesions.
Optimal time-varying coupling function can enhance synchronization in complex networks
Authors: Dayani Zahra , Parastesh Fatemeh , Nazarimehr Fahimeh , Rajagopal Karthikeyan , Jafari Sajad , Schöll Eckehard , Kurths Jürgen
Published: March 2023

In this paper, we propose a time-varying coupling function that results in enhanced synchronization in complex networks of oscillators. The stability of synchronization can be analyzed by applying the master stability approach, which considers the largest Lyapunov exponent of the linearized variational equations as a function of the network eigenvalues as the master stability function. Here, it is assumed that the oscillators have diffusive single-variable coupling. All possible single-variable couplings are studied for each time interval, and the one with the smallest local Lyapunov exponent is selected. The obtained coupling function leads to a decrease in the critical coupling parameter, resulting in enhanced synchronization. Moreover, synchronization is achieved faster, and its robustness is increased. For illustration, the optimum coupling function is found for three networks of chaotic Rössler, Chen, and Chua systems, revealing enhanced synchronization.
Nanoscale thermal interface rectification in the quantum regime
Authors: Dai Jinghang , Tian Zhiting
Published: March 2023

To enable the on-demand control of heat flow for sustainable energy solutions, we have been longing for functional thermal components at the nanoscale, in analogue to electronic diodes and transistors. Understanding and discovering fundamental mechanisms that drive thermal rectification are critical to advancing this field. Different mechanisms have been proposed for thermal rectification effects in the classical regime. Using anharmonic atomistic Green's function, we discovered a thermal rectification phenomenon in the quantum regime for nanometer-thick three-dimensional solid interfaces. We found that the anharmonic phonon scatterings across the interface act on the temperature-dependent phonon populations on both sides of the interface, generating the necessary nonlinearity to achieve thermal rectification. This intrinsic thermal interface rectification is a universal phenomenon that can be observed and engineered for nanoscale interfaces.
Metrological analysis of the four-point bending test for quantifying the photoelastic behavior of materials
Authors: Solaguren-Beascoa Fernández M.
Published: March 2023

In this work, a method for evaluating stress-optic coefficient measurements and their uncertainty on a four-point bending specimen is presented. Other previously used methods approached this issue by considering multiple data through an ordinary least squares fit; but they only take into account the repeatability contribution to uncertainty, so they are not consistent with the ISO-Guide to the expression of Uncertainty in Measurement. The method presented here uses a general least squares fit with which it is possible to consider all possible contributions to uncertainty. The application of the method is illustrated with an example, from which it can be seen that uncertainty has been underestimated in the results of the other methods used to date. In addition to the estimate of the stress-optic coefficient and its corresponding standard uncertainty, the method also provides a test to check the consistency of the data and an outlier identification tool.
Spatial distribution of the quantized vortices' tangle in thermally driven round jets of superfluid helium
Authors: Švančara P. , Roche P.-E. , La Mantia M.
Published: March 2023

Thermally driven flows of superfluid 4He display unique features, often related to the presence of quantized vortices—line singularities embedded in the liquid. Here, we focus on turbulent round jets, experimentally investigated using the flow visualization and second sound attenuation techniques, at Reynolds numbers exceeding 104. These turbulent flows are driven by releasing heat into a small volume of liquid, open to the surrounding bath through a cylindrical nozzle, 2 mm in diameter. Our measurements reveal in unprecedented detail how the tangle of quantized vortices associated with the jets arranges itself in space, for distances ranging from 9 to 34 nozzle diameters, at fluid temperatures between 1.64 and 2.10 K. We specifically find that the vortex tangle spreads in the radial direction, while it dilutes away from the nozzle. Additionally, the tangle density is found to systematically depend on the flow forcing. Two physical interpretations of the observed behavior are proposed, which could motivate further investigations of this peculiar flow. One leads us to conjecture a self-similar functional form of the vortex tangle density across counterflow jets. The other suggests that the position of the superfluid stagnation point—a characteristic feature of counterflow jets—could depend on the flow forcing as well.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: March 2023

To supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials that supersede earlier data or suggest new research applications.
Silver nanoparticles affect wheat (Triticum aestivum L.) germination, seedling blight and yield
Authors: Matras Ewelina , Gorczyca Anna , Pociecha Ewa , Przemieniecki Sebastian Wojciech , Żeliszewska Paulina , Oćwieja Magdalena
Published: March 2023

The aim of the study was to evaluate the effect of two types of negatively charged quasi-spherical silver nanoparticles (AgNPs) at concentrations of 10, 20 and 30 mg L−1 and silver ions at a concentration of 30 mg L−1 on the growth, selected physiological aspects and yielding of wheat (Triticum aestivum L.) cv. Tybalt, and on plant resistance to seedling blight. Seed germination, α-amylase activity in seeds, morphology and infestation of seedlings by pathogens were assessed in a hydroponic treatment. Growth rate, PSII efficiency, heading and yield of the same plants were then analysed in pot culture. Results showed that the AgNPs and silver ions had a negative effect on roots, but reduced seedling blight and improved leaf area compared to the control. In addition, the AgNPs reduced with sodium borohydride in the presence of trisodium citrate at concentrations of 10 and 20 mg L−1 stimulated germination, α-amylase activity and shoot length, which was not observed in the case of silver ions and the AgNPs reduced with sodium hypophosphite in the presence of sodium hexametaphosphate. In a pot experiment, the AgNPs improved plant growth, PSII efficiency, accelerated heading and increased yield-related parameters compared with the control. Results revealed the interaction strength in the following order: TCSB-AgNPs > SHSH-AgNPs > silver ions. TCSB-AgNPs in the lowest concentration had the most favourable effect, indicating their great potential for use in improving wheat cultivation.
Activation of the nociceptin/orphanin-FQ receptor promotes NREM sleep and EEG slow wave activity
Authors: Morairty Stephen R. , Sun Yu , Toll Lawrence , Bruchas Michael R. , Kilduff Thomas S.
Published: March 2023

Sleep/wake control involves several neurotransmitter and neuromodulatory systems yet the coordination of the behavioral and physiological processes underlying sleep is incompletely understood. Previous studies have suggested that activation of the Nociceptin/orphanin FQ (N/OFQ) receptor (NOPR) reduces locomotor activity and produces a sedation-like effect in rodents. In the present study, we systematically evaluated the efficacy of two NOPR agonists, Ro64-6198 and SR16835, on sleep/wake in rats, mice, and Cynomolgus macaques. We found a profound, dose-related increase in non-Rapid Eye Movement (NREM) sleep and electroencephalogram (EEG) slow wave activity (SWA) and suppression of Rapid Eye Movement sleep (REM) sleep in all three species. At the highest dose tested in rats, the increase in NREM sleep and EEG SWA was accompanied by a prolonged inhibition of REM sleep, hypothermia, and reduced locomotor activity. However, even at the highest dose tested, rats were immediately arousable upon sensory stimulation, suggesting sleep rather than an anesthetic state. NOPR agonism also resulted in increased expression of c-Fos in the anterodorsal preoptic and parastrial nuclei, two GABAergic nuclei that are highly interconnected with brain regions involved in physiological regulation. These results suggest that the N/OFQ–NOPR system may have a previously unrecognized role in sleep/wake control and potential promise as a therapeutic target for the treatment of insomnia.
Triadic influence as a proxy for compatibility in social relationships
Authors: Ruiz-García Miguel , Ozaita Juan , Pereda María , Alfonso Antonio , Brañas-Garza Pablo , Cuesta José A. , Sánchez Angel
Published: March 2023

Networks of social interactions are the substrate upon which civilizations are built. Often, we create new bonds with people that we like or feel that our relationships are damaged through the intervention of third parties. Despite their importance and the huge impact that these processes have in our lives, quantitative scientific understanding of them is still in its infancy, mainly due to the difficulty of collecting large datasets of social networks including individual attributes. In this work, we present a thorough study of real social networks of 13 schools, with more than 3,000 students and 60,000 declared positive and negative relationships, including tests for personal traits of all the students. We introduce a metric—the “triadic influence”—that measures the influence of nearest neighbors in the relationships of their contacts. We use neural networks to predict the sign of the relationships in these social networks, extracting the probability that two students are friends or enemies depending on their personal attributes or the triadic influence. We alternatively use a high-dimensional embedding of the network structure to also predict the relationships. Remarkably, using the triadic influence (a simple one-dimensional metric) achieves the best accuracy, and adding the personal traits of the students does not improve the results, suggesting that the triadic influence acts as a proxy for the social compatibility of students. We postulate that the probabilities extracted from the neural networks—functions of the triadic influence and the personalities of the students—control the evolution of real social networks, opening an avenue for the quantitative study of these systems.
Patterning of morphogenetic anisotropy fields
Authors: Wang Zihang , Marchetti M. Cristina , Brauns Fridtjof
Published: March 2023

Orientational order, encoded in anisotropic fields, plays an important role during the development of an organism. A striking example of this is the freshwater polyp
Hydra
, where topological defects in the muscle fiber orientation have been shown to localize to key features of the body plan. This body plan is organized by morphogen concentration gradients, raising the question how muscle fiber orientation, morphogen gradients and body shape interact. Here, we introduce a minimal model that couples nematic orientational order to the gradient of a morphogen field. We show that on a planar surface, alignment to a radial concentration gradient can induce unbinding of topological defects, as observed during budding and tentacle formation in
Hydra
, and stabilize aster/vortex-like defects, as observed at a
Hydra
’s mouth. On curved surfaces mimicking the morphologies of
Hydra
in various stages of development—from spheroid to adult—our model reproduces the experimentally observed reorganization of orientational order. Our results suggest how gradient alignment and curvature effects may work together to control orientational order during development and lay the foundations for future modeling efforts that will include the tissue mechanics that drive shape deformations.
A c-di-GMP binding effector controls cell size in a cyanobacterium
Authors: Zeng Xiaoli , Huang Min , Sun Qing-Xue , Peng Ye-Jun , Xu Xiaomei , Tang Yun-Bin , Zhang Ju-Yuan , Yang Yiling , Zhang Cheng-Cai
Published: March 2023

Cyclic-di-GMP (c-di-GMP) is a ubiquitous bacterial signaling molecule. It is also a critical player in the regulation of cell size and cell behaviors such as cell aggregation and phototaxis in cyanobacteria, which constitute an important group of prokaryotes for their roles in the ecology and evolution of the Earth. However, c-di-GMP receptors have never been revealed in cyanobacteria. Here, we report the identification of a c-di-GMP receptor, CdgR, from the filamentous cyanobacterium
Anabaena
PCC 7120. Crystal structural analysis and genetic studies demonstrate that CdgR binds c-di-GMP at the dimer interface and this binding is required for the control of cell size in a c-di-GMP-dependent manner. Different functions of CdgR, in ligand binding and signal transmission, could be separated genetically, allowing us to dissect its molecular signaling functions. The presence of the apo-form of CdgR triggers cell size reduction, consistent with the similar effects observed with a decrease of c-di-GMP levels in cells. Furthermore, we found that CdgR exerts its function by interacting with a global transcription factor DevH, and this interaction was inhibited by c-di-GMP. The lethal effect triggered by conditional depletion of DevH or by the production of several point-mutant proteins of CdgR in cells indicates that this signaling pathway plays critical functions in
Anabaena
. Our studies revealed a mechanism of c-di-GMP signaling in the control of cell size, an important and complex trait for bacteria. CdgR is highly conserved in cyanobacteria, which will greatly expand our understanding of the roles of c-di-GMP signaling in these organisms.
Effects of Zn addition on the microstructure and properties of Cu–Cr alloys
Authors: Ma Yaxing , Lei Qian , Xu Jinjun , Liang Yuxin , Meng Xiangpeng , Li Yibo , Xiao Zhu
Published: March 2023

Many attempts were conducted to improve Cu–Cr alloys’ softening temperature, strength, and electrical conductivity. After homogenised treatment at 900°C for 4 h, hot rolled by 80% at 900°C, solid solution treated at 940°C for 2 h, cold rolled by 50%, and aged at 450°C for 1 h, cold rolled by 50%, and aged at 450°C for 0.5 h, the tensile strength, yield strength, microhardness, and electrical conductivity of the fabricated Cu–2Cr–1Zn alloy were 616.7, 540.1 MPa, 176.7 HV, and 71.5% IACS, respectively, with a softening temperature of 530°C. Orowan precipitation strengthening was the primary strengthening mechanism. These findings bring an effective way to improve the strength and softening temperature with a small loss of electrical conductivity.
Conductive and anti-bacterial self-bundled nanofibrous yarns from electrostatic induction of Keggin polyoxometalates
Authors: Arin Jirapong , Panith Pasinee , Subjalearndee Nakarin , Thongkam Pech , Intasanta Varol
Published: March 2023

A facile and effective means of nanofibres’ self-twisting is pioneered under a strong electrostatic induction during electrospinning process. The assembly of self-bundled nanofibre yarns is driven by the attractive forces induced by the interactions between highly charged and ionic tungsten (VI) in ammonium metatungstate that bonds with cyanide group of polyacrylonitrile under the electric field during electrospinning process. The nanofibre yarns are further photo-deposited with silver nitrate and graphene oxide dispersion to obtain electrically conductive and anti-bacterial properties. Tenacity and breaking strain of the Ag/GO modified nanofibre yarns improve more than 10-fold and 60% of the nanofibre yarns, respectively. Moreover, the Ag/GO modified nanofibre yarn shows >99.98% anti-bacterial against both gram-positive ( Staphylococcus aureus) and gram-negative ( Klebsiella pneumoniae) bacteria.

GRAPHICAL ABSTRACT
The meiotic LINC complex component KASH5 is an activating adaptor for cytoplasmic dynein
Authors: Garner Kirsten E.L. , Salter Anna , Lau Clinton K. , Gurusaran Manickam , Villemant Cécile M. , Granger Elizabeth P. , McNee Gavin , Woodman Philip G. , Davies Owen R. , Burke Brian E. , Allan Victoria J.
Published: March 2023

Cytoplasmic dynein-driven movement of chromosomes during prophase I of mammalian meiosis is essential for synapsis and genetic exchange. Dynein connects to chromosome telomeres via KASH5 and SUN1 or SUN2, which together span the nuclear envelope. Here, we show that KASH5 promotes dynein motility in vitro, and cytosolic KASH5 inhibits dynein’s interphase functions. KASH5 interacts with a dynein light intermediate chain (DYNC1LI1 or DYNC1LI2) via a conserved helix in the LIC C-terminal, and this region is also needed for dynein’s recruitment to other cellular membranes. KASH5’s N-terminal EF-hands are essential as the interaction with dynein is disrupted by mutation of key calcium-binding residues, although it is not regulated by cellular calcium levels. Dynein can be recruited to KASH5 at the nuclear envelope independently of dynactin, while LIS1 is essential for dynactin incorporation into the KASH5–dynein complex. Altogether, we show that the transmembrane protein KASH5 is an activating adaptor for dynein and shed light on the hierarchy of assembly of KASH5–dynein–dynactin complexes.
Sniffing out Ca2+ signaling in olfactory cilia
Authors: Short Ben
Published: March 2023

JGP study (Takeuchi and Kurahashi. 2023. J. Gen. Physiol.https://doi.org/10.1085/jgp.202213165) reveals that segregation of signals within sensory cilia allows Ca2+ to play opposing roles in olfactory signal transduction.
Laser-Chirp Controlled Terahertz Wave Generation from Air Plasma
Authors: Xu Xing , Huang Yindong , Zhang Zhelin , Liu Jinlei , Lou Jing , Gao Mingxin , Wu Shiyou , Fang Guangyou , Zhao Zengxiu , Chen Yanping , Sheng Zhengming , Chang Chao
Published: March 2023

We report the laser-chirp controlled terahertz (THz) wave generation from two-color-laser-induced air plasma. Our experimental results reveal that the THz wave is affected by both the laser energy and chirp, leading to radiation minima that can be quantitatively reconstructed using the linear-dipole-array model. The phase difference between the two colors, determined by the chirp and intensity of the laser, can account for the radiation minima. Furthermore, we observe an asynchronous variation in the generated THz spectrum, which suggests a THz frequency-dependent phase matching between the laser pulse and THz wave. These results highlight the importance of laser chirp during the THz wave generation and demonstrate the possibility of modulating the THz yields and spectrum through chirping the incident laser pulse. This work can provide valuable insights into the mechanism of plasma-based THz wave generation and offer a unique means to control THz emissions.
Norm-dependent convergence and stability of the inverse scattering series for diffuse and scalar waves
Authors: Mahankali Srinath , Yang Yunan
Published: March 2023

This work analyzes the forward and inverse scattering series for scalar waves based on the Helmholtz equation and the diffuse waves from the time-independent diffusion equation, which are important partial differential equations (PDEs) in various applications. Different from previous works, which study the radius of convergence for the forward and inverse scattering series, the stability, and the approximation error of the series under the L

p
norms, we study these quantities under the Sobolev H

s
norm, which associates with a general class of L
2-based function spaces. The H

s
norm has a natural spectral bias based on its definition in the Fourier domain: the case s < 0 biases towards the lower frequencies, while the case s > 0 biases towards the higher frequencies. We compare the stability estimates using different H

s
norms for both the parameter and data domains and provide a theoretical justification for the frequency weighting techniques in practical inversion procedures. We also provide numerical inversion examples to demonstrate the differences in the inverse scattering radius of convergence under different metric spaces.
A simple data-driven level finding method of many-electron atoms and heavy nuclei based on statistical outlier detection
*
Authors: Hongu Kazuaki , Fujii Keisuke
Published: March 2023

We report a simple and pure data-driven method to find new energy levels of quantum many-body systems only from observed line wavelengths. In our method, all the possible combinations are computed from known energy levels and wavelengths of unidentified lines. As each excited state exhibits many transition lines to different lower levels, the true levels should be reconstructed coincidentally from many level-line combinations, while the wrong combinations distribute randomly. Such a coincidence can be easily detected statistically. We demonstrate this statistical method by finding new levels for various atomic and nuclear systems from unidentified line lists available online.
Nematicity-enhanced superconductivity in systems with a non-Fermi liquid behavior
Authors: Sayyad Sharareh , Kitatani Motoharu , Vaezi Abolhassan , Aoki Hideo
Published: March 2023

We explore the interplay between nematicity (spontaneous breaking of the sixfold rotational symmetry), superconductivity, and non-Fermi liquid behavior in partially flat-band (PFB) models on the triangular lattice. A key result is that the nematicity (Pomeranchuk instability), which is driven by many-body effect and stronger in flat-band systems, enhances superconducting transition temperature in a systematic manner on the T
c dome. There, a plausible

s

x
2

+

y
2

−

d

x
2

−

y
2

−

d

x
y

-wave symmetry, in place of the conventional

d

x
2

−

y
2

-wave, governs the nematicity-enhanced pairing with a sharp rise in the T
c dome on the filling axis. When the sixfold symmetry is spontaneously broken, the pairing interaction is shown to become stronger with more compact pairs in real space than when the symmetry is enforced. These are accompanied by a non-Fermi character of electrons in the PFBs with many-body interactions.
Tunable zero-energy Dirac and Luttinger nodes in a two-dimensional topological superconductor
Authors: Mays R , Nikolić P
Published: March 2023

Cooper pairing in ultrathin films of topological insulators, induced intrinsically or by proximity effect, can produce an energetically favorable spin-triplet superconducting state. The spin–orbit coupling acts as an SU(2) gauge field and stimulates the formation of a spin-current vortex lattice in this superconducting state. Here we study the Bogoliubov quasiparticles in such a state and find that the quasiparticle spectrum consists of a number of Dirac nodes pinned to zero energy by the particle-hole symmetry. Some nodes are ‘accidental’ and move through the first Brillouin zone along high-symmetry directions as the order parameter magnitude or the strength of the spin–orbit coupling are varied. At special parameter values, nodes forming neutral quadruplets merge and become gapped out, temporarily producing a quadratic band-touching spectrum. All these features are tunable by controlling the order parameter magnitude via a gate voltage in a heterostructure device. In addition to analyzing the spectrum at the mean-field level, we briefly discuss a few experimental signatures of this spectrum.
A new meta-transfer learning method with freezing operation for few-shot bearing fault diagnosis
Authors: Wang Peiqi , Li Jingde , Wang Shubei , Zhang Fusheng , Shi Juanjuan , Shen Changqing
Published: March 2023

Deep learning for bearing fault diagnosis often requires a large quantity of comprehensive data to give support in the field of rotating machinery fault diagnosis. However, large-quantity datasets for model training are difficult to obtain in actual working environments. Therefore, bearing fault diagnosis problems under practical working conditions are often considered few-shot problems. Meta-learning can be adopted to solve these few-shot problems. Traditional meta-learning methods, however, can lead to model overfitting, and shallow neural networks are usually used to avoid overfitting. As a result, the features extracted by the shallow neural network are insufficiently rich to exploit the optimal performance of the model. A few-shot fault diagnosis method based on meta-learning, named meta-transfer learning with freezing operation (MTLFO), is proposed in this study to solve these problems. MTLFO can learn new knowledge rapidly through a small number of samples. The hyperparameter self-regulation ability of meta-learning is adopted by MTLFO, and a freezing operation is used to deal with the neuronal nature of meta-learning to ensure that the neurons from different tasks are transferred by utilizing scaling and shifting. MTLFO avoids the overfitting problem in traditional meta-learning methods and presents more advantages in solving few-shot problems in fault diagnosis compared with other types of methods.