bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nickel(II) Thiocyanate Complex as a Catalyst for Cross-Coupling Reactions
Authors: Mori Atsunori , Yamaoka Seiha , Fukuoka Hiroyuki , Noda Naoki , Okano Kentaro , Horie Masaki 
Published: March 2023

AbstractA nickel thiocyanate complex was prepared by the reaction of Ni(NCS)2 with (2S,3S)-2,3-bis(diphenylphosphino)butane (Chiraphos) by following a method reported in the literature. The resulting nickel complex was found to be active in the polymerization reactions of 1,4-dihalobenzenes and 2-halo-3-hexylthiophenes, leading to poly-1,4-phenylenes and poly(3-hexylthiophene-2,5-diyl), respectively. The polymerization in the presence of similar catalysts containing other ligands, such as 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, or N-heterocyclic carbenes, also proceeded in a similar manner. Ni(NCS)2 complexes also successfully catalyzed Suzuki–Miyaura couplings and Buchwald–Hartwig aminations to afford the corresponding biaryls and arylamines, respectively.
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

Abstract
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

Abstract
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.
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.
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.
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 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.
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
Norm-dependent convergence and stability of the inverse scattering series for diffuse and scalar waves
Authors: Mahankali Srinath , Yang Yunan 
Published: March 2023

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Ponderomotive forces due to electron modes in unmagnetized plasmas described by kappa distribution functions
Authors: Espinoza-Troni Joaquín , A Asenjo Felipe , Moya Pablo S 
Published: March 2023

Abstract
The Washimi and Karpman ponderomotive interaction due to electron wave propagation is investigated for low-temperature unmagnetized plasmas described by an isotropic kappa distribution. We perform a brief analysis of the influence of the kappa distribution in the dispersion relations for a low-temperature plasma expansion at the lowest order in which the thermal effects are appreciable without considering the damping characteristics of the wave. The spatial and temporal factors of the ponderomotive force are obtained as a function of the wavenumber, the spectral index κ and the ratio between the plasma thermal velocity and the speed of light. Our results show that for unmagnetized plasmas non-thermal effects are negligible due to the spatial ponderomotive force when non-relativistic thermal velocities are considered. However, for unmagnetized plasmas, the temporal factor of the ponderomotive force appears only due to the presence of suprathermal particles, with a clear dependence on the κ index. We also analyze the role of the non-thermal effect in the induced Washimi and Karpman ponderomotive magnetization and the total power radiated associated with it. Furthermore, we show that the magnitude of the slowly varying induced ponderomotive magnetic field increases as the plasma moves away from thermal equilibrium.
InGaN/AlInN interface with enhanced holes to improve photoelectrochemical etching and GaN device release
Authors: Shaban Zeinab , Zubialevich Vitaly Z , Amargianitakis Emmanouil A , Atar Fatih Bilge , Parbrook Peter James , Li Zhi , Corbett Brian 
Published: March 2023

Abstract
We introduce a novel superlattice structure for releasing GaN-based devices with selective photo-electrochemical (PEC) etching by incorporating a lattice-matched AlInN barrier in an InGaN/GaN sacrificial stack. A dopant-free two-dimensional hole gas is formed at the InGaN/AlInN interface due to the band bending and strong polarization discontinuity, which is revealed in simulations. PEC etching using the four period InGaN/AlInN superlattice exhibits almost three times higher etch rate and smoother etched surfaces when compared to conventional InGaN/GaN release layers. A systematic investigation with different AlInN layer thicknesses shows that a thin AlInN layer is able to achieve smooth surface with uniform etch process during the PEC while thicker AlInN exhibits poorer surface morphology although the etch rate was faster. Furthermore, it is found that using HNO3 as the electrolyte improved the etched surface smoothness compared to KOH when followed by a post-release HCl treatment. This structure will enable the release of high quality GaN layers and the fabrication of novel optical devices.
Tribological properties of PEEK-based composite coating prepared by thermal spraying
Authors: Zhang Yu Xi , Chen Xue Hui , Li Jian , Li Cong Min , Li Xiang , Gao Ting , Li Hao , Jing Tian Tian , Liu Wei 
Published: March 2023

Abstract
To improve the friction wear performance of the aluminum alloy scroll disc of the scroll compressor under dry friction conditions, the C-MoS2-PTFE-PEEK coating was prepared on the surface of the 4032 aluminum alloy substrate by thermal spraying. The friction and wear performance of C-MoS2-PTFE-PEEK coating under dry friction conditions was investigated via friction wear test, hardness test, coating adhesion scratch test, x-ray diffraction analysis test, morphological characteristics, element distribution test, And XPS photoelectron spectrometer. Moreover, the frictional wear performance of the C-MoS2-PTFE-PEEK coating was compared with that of the anodic oxide film of 4032 aluminum alloy and the Ni-plated coating of 4032 aluminum alloy. The results show that the hardness of C-MoS2-PTFE-PEEK coating is 102.8 HV0.2. The C-MoS2-PTFE-PEEK coating has good lubrication properties under dry friction conditions due to the synergistic effect of MoS2 and PTFE, which can effectively resist deformation and reduce the coefficient of friction. The average friction coefficient under 5N, 10N, and 15N loads are 0.12, 0.15, and 0.23, respectively. The Graphite can effectively form a solid lubricating film, improve the adhesion resistance of the composite, and cause the shallow and small wear mark of C-MoS2-PTFE-PEEK coating; The wear rate and friction coefficient of C-MoS2-PTFE-PEEK coating under different loads are lower than that of the anodic oxidation film of 4032 aluminum alloy and the Ni-plated coating of 4032 aluminum alloy, showing excellent anti-friction and wear resistance. The wear mechanism of C-MoS2-PTFE-PEEK coating under different loads is mainly fatigue wear, adhesive wear, and abrasive wear.