bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of quinazoline by decarboxylation of 2-aminobenzylamine and α-keto acid under visible light catalysis
Authors: Yang Jiangnan , Xie Zongbo , Jin Liang , Chen Xuehua , Le Zhanggao
Published: April 2022

Quinazoline compounds were synthesized using α-keto acid as the acyl source under blue LED irradiation at room temperature without transition metal catalysts or additives.
Proton gated oxide neuromorphic transistors with bionic vision enhancement and information decoding
Authors: Ren Zheng Yu , Kong Yun Hui , Ai Ling , Xiao Hui , Wang Wei Sheng , Shi Zhi Wen , Zhu Li Qiang
Published: April 2022

A bionic vision enhancement and information decoding platform using proton gated oxide neuromorphic transistors is proposed, which exhibits a high recognition accuracy of ∼94.73% and information decoding function.
Performance analysis of full‐duplex device‐to‐device transmitter aided non‐orthogonal multiple access
Authors: Bai Lijun , Hao Li , Jia Ke jun
Published: April 2022

In this paper, a three‐user non‐orthogonal multiple access (NOMA) system based on device‐to‐device (D2D) communication and full‐duplex (FD) transmission is proposed, in which the D2D user acts as a decode‐and‐forward (DF) relay to forward the signal from the base station (BS) to the far user, forming a system termed the FD D2D transmitter aided NOMA (FD‐D2D‐NOMA). In practical NOMA systems, due to the limitation of decoding ability, the near user cannot always perform successive interference cancellation (SIC) successfully. By considering perfect SIC (pSIC) and imperfect SIC (ipSIC), the close‐form expressions for the ergodic sum capacity and outage probability of the proposed FD‐D2D‐NOMA scheme are derived, which match well with the simulation ones. The ergotic sum capacity and outage probability under different levels of residual self‐interference at the FD user and residual interference at the far/near user due to ipSIC are investigated, and the results show that, such interferences have significant impact on the performance of the proposed scheme. Moreover, the analytical and simulation results illustrate the performance gain of the proposed scheme compared with other ones under both pSIC and ipSIC scenarios. The impacts on performance exerted by channel conditions and design parameters are also discussed in this paper.
Open‐set iris recognition based on deep learning
Authors: Sun Jie , Zhao Shipeng , Miao Sheng , Wang Xuan , Yu Yanan
Published: April 2022

The existing iris recognition methods offer excellent recognition performance for known classes, but they do not consider the rejection of unknown classes. It is important to reject an unknown object class for a reliable iris recognition system. This study proposes open‐set iris recognition based on deep learning. In the method, by training the deep network, the extracted iris features are clustered near the feature centre of each kind of iris image. Then, the authors build an open‐class features outlier network (OCFON) containing distance features, which maps the features extracted by the deep network to a new feature space and classifies them. Finally, the unknown class samples are determined by a SoftMax probability threshold. The authors conducted experiments on the open iris dataset constructed using the iris datasets CASIA‐Iris‐Twins and CASIA‐Iris‐Lamp. The experiment shows that the proposed method has good open‐set iris recognition performance, can effectively distinguish iris samples of unknown classes, and has little impact on the recognition ability of known classes of iris samples.
Power‐frequency oscillation suppression algorithm for AC microgrid with multiple virtual synchronous generators based on fuzzy inference system
Authors: Zhang Liang , Zheng Hao , Cai Guowei , Zhang Zhe , Wang Xuesong , Koh Leong Hai
Published: April 2022

In the microgrid, virtual synchronous generator technology can significantly enhance the anti‐interference characteristics of the system frequency and bus voltage, as well as solve the problems of insufficient damping and low inertia. However, the system frequency and active power oscillation caused by power fluctuations and grid faults threaten the stable operation of the grid seriously. Therefore, for an alternating current (AC) microgrid multi‐virtual synchronous generator (VSG) parallel system, an improved virtual synchronous generator control algorithm based on a fuzzy inference system is proposed, which adjusts the values of virtual inertia and damping coefficient dynamically through fuzzy logic rules to realize the coordinated control of the two. The enhanced VSG algorithm described in this research has a substantial influence on power‐frequency oscillation suppression, decreases active power and frequency overshoot, shortens the adjustment time, and improves system frequency stability active power, according to simulation and experimental findings.
KMT-2021-BLG-1077L: The fifth confirmed multiplanetary system detected by microlensing
Authors: Han Cheongho , Gould Andrew , Bond Ian A. , Kil Jung Youn , Albrow Michael D. , Chung Sun-Ju , Hwang Kyu-Ha , Ryu Yoon-Hyun , Shin In-Gu , Shvartzvald Yossi , Yee Jennifer C. , Zang Weicheng , Cha Sang-Mok , Kim Dong-Jin , Kim Seung-Lee , Lee Chung-Uk , Lee Dong-Joo , Lee Yongseok , Park Byeong-Gon , Pogge Richard W. , Kim Doeon ,   (The KMTNet collaboration), Abe Fumio , Barry Richard K. , Bennett David P. , Bhattacharya Aparna , Fujii Hirosane , Fukui Akihiko , Hirao Yuki , Itow Yoshitaka , Kirikawa Rintaro , Koshimoto Naoki , Kondo Iona , Matsubara Yutaka , Matsumoto Sho , Miyazaki Shota , Muraki Yasushi , Olmschenk Greg , Okamura Arisa , Ranc Clément , Rattenbury Nicholas J. , Satoh Yuki , Silva Stela Ishitani , Sumi Takahiro , Suzuki Daisuke , Toda Taiga , Tristram Paul J. , Vandorou Aikaterini , Yama Hibiki ,   (The MOA Collaboration)
Published: April 2022

Aims. The high-magnification microlensing event KMT-2021-BLG-1077 exhibits a subtle and complex anomaly pattern in the region around the peak. We analyze the lensing light curve of the event with the aim of revealing the nature of the anomaly.

Methods. We test various models in combination with several interpretations: that the lens is a binary (2L1S), the source is a binary (1L2S), both the lens and source are binaries (2L2S), or the lens is a triple system (3L1S). We search for the best-fit models under the individual interpretations of the lens and source systems.

Results. We find that the anomaly cannot be explained by the usual three-body (2L1S and 1L2S) models. The 2L2S model improves the fit compared to the three-body models, but it still leaves noticeable residuals. On the other hand, the 3L1S interpretation yields a model explaining all the major anomalous features in the lensing light curve. According to the 3L1S interpretation, the estimated mass ratios of the lens companions to the primary are ~1.56 × 10−3 and ~1.75 × 10−3, which correspond to ~1.6 and ~1.8 times the Jupiter/Sun mass ratio, respectively, and therefore the lens is a multiplanetary system containing two giant planets. With the constraints of the event time-scale and angular Einstein radius, it is found that the host of the lens system is a low-mass star of mid-to-late M spectral type with amass of Mh = 0.14−0.07+0.19 MΘ, and it hosts two gas giant planets with masses of Mp1 = 0.22−0.12+0.31 MJ and Mp2 = 0.25−0.13+0.35. The planets lie beyond the snow line of the host with projected separations of a⊥,p1 = 1.26−1.08+1.41 AU and a⊥,p2 = 0.93−0.80+1.05 AU. The planetary system resides in the Galactic bulge at a distance of DL = 8.24−1.16+1.02 kpc. The lens of the event is the fifth confirmed multiplanetary system detected by microlensing following OGLE-2006-BLG-109L, OGLE-2012-BLG-0026L, OGLE-2018-BLG-1011L, and OGLE-2019-BLG-0468L.
Mathematical modeling of Aphron drilling nanofluid driven by electroosmotically modulated peristalsis through a pipe
Authors: Akram Javaria , Akbar Noreen Sher
Published: April 2022

This analysis is conducted for a theoretical examination of the fluid flow characteristics and heat transferred by the nanoparticle-enhanced drilling muds flowing through drilling pipes under various physical conditions. Here, an important type of drilling fluid called Aphron drilling fluid is under consideration which is very effective for drilling in depleted regions. The rheological characteristics of the drilling fluid are predicted by Herschel-Bulkley fluid model. The fluid flow is driven by peristaltic pumping which is further aided by electroosmosis. The zinc oxide nanoparticles are dispersed in the aphron drilling fluid to prepare the nanofluid. The administering set of equations is simplified under the lubrication approach and the closed-form solutions are obtained for velocity and pressure gradient force. However, numerical solutions are executed for the temperature of nanofluid through built-in routine bvp4c of MATLAB. Fluid flow characteristics are analyzed for variation in physical conditions through graphical results. The outcomes of this study reveal that velocity profile substantially rises for application of forwarding electric field and temperature profile significantly decays in this case. An increment in temperature difference raises the magnitude of the Nusselt number. Furthermore, the nanoparticle volume fraction contributes to fluid acceleration and thermal conductivity of the drilling fluid.
Inversion formulae for ray transforms in vector and tensor tomography
Authors: Louis Alfred K
Published: April 2022

Ray transforms for vector or tensor fields have been studied for a long time, also in connection with Doppler or polarization tomography. In contrast to the classical Radon transform or x-ray transform their known inversion formulae are rather complicated, and represented, for example, using series expansions or singular value decompositions. Recently, applications of the approximate inverse have been studied. In this paper we present a new class of inversion formulae for compactly supported fields similar to those of the x-ray transform. The derivation is based on two observations. First, we apply Derevtsov’s formula relating the ray transforms of vector or tensor fields to a derivative of the x-ray transform of a generating potential, [3]. Second, we apply the calculation of derivatives of a scalar function from its x-ray transform, as it is realized in feature reconstruction, [15, 16]. Generalizations complete the presentation.
SU(3)-transformation-based inverse engineering for fast population transfer in three-level systems
Authors: Li Wei , Song Yu
Published: April 2022

We propose a scheme to inverse engineer the Hamiltonian of any general driven three-level system by employing a SU(3) transformation. For special cases, the scheme is then introduced to explore nonadiabatic dynamic evolution of systems with two-photon resonance. We demonstrate that, by selecting the control parameters with explicit function forms, both the ideal process and the practical evolution driving with the truncation of pulses, systematic error and decaying can implement fast population transfer with high fidelity. Moreover, the nonadiabatic passages are not reconstructed by the superadiabatic approach.
Quantum droplets in three-dimensional Bose–Einstein condensates
Authors: Otajonov Sherzod R
Published: April 2022

The properties of 3D Bose–Einstein condensate have been studied with variational and numerical methods. In the variational approach, we use the super-Gaussian trial function, and it is demonstrated that this trial function is a good approach for providing the descriptions of the quantum droplets. The analytical equations for the variational parameters are obtained. The frequency of small oscillations of quantum droplets near the equilibrium position is estimated. It is also found that periodic modulation of the coupling constants leads to resonance oscillations of the quantum droplets parameters or emission of waves depending on the amplitude of the modulations. The predictions are supported by direct numerical simulation of the governing equation.
About the possibility for using graphene layers 12
C–13
C for quantum computation
Authors: López Gustavo V , Vizcaíno G Jorge O
Published: April 2022

We used a graphene 12
C matrix doped with 13
C atoms in a squared and center-triangular configuration, where only the interaction 13
C–13
C with their magnetic moments are considered. This is done in the presence of a constant magnetic field parallel to the layers and a transverse rf-magnetic field in order to simulate the NOT gate (single layer), controlled-not quantum gate (two layers), and controlled-controlled-not quantum gate (three layers). However, as it would be explained in more detail throughout this article, a single qubit rotation defined by a single graphene layer was not possible to construct. We found that frequencies needed to perform this transitions do not depend on the number of 13
C atoms on each layer, which means that we can make transitions between two distant states with big separation of energy levels (m and n states) with lower frequency pulses

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Competitive protein adsorption on charge regulating silica-like surfaces: the role of protonation equilibrium
Authors: Cathcarth Marilina , Picco Agustin S , Mondo Gabriela B , Cardoso Mateus B , Longo Gabriel S
Published: April 2022

We develop a molecular thermodynamic theory to study the interaction of some proteins with a charge regulating silica-like surface under a wide range of conditions, including pH, salt concentration and protein concentration. Proteins are modeled using their three dimensional structure from crystallographic data and the average experimental pKa of amino acid residues. As model systems, we study single-protein and binary solutions of cytochrome c, green fluorescent protein, lysozyme and myoglobin. Our results show that protonation equilibrium plays a critical role in the interactions of proteins with these type of surfaces. The terminal hydroxyl groups on the surface display considerable extent of charge regulation; protein residues with titratable side chains increase protonation according to changes in the local environment and the drop in pH near the surface. This behavior defines protein–surface interactions and leads to the emergence of several phenomena: (i) a complex non-ideal surface charge behavior; (ii) a non-monotonic adsorption of proteins as a function of pH; and (iii) the presence of two spatial regions, a protein-rich and a protein-depleted layer, that occur simultaneously at different distances from the surface when pH is slightly above the isoelectric point of the protein. In binary mixtures, protein adsorption and surface–protein interactions cannot be predicted from single-protein solution considerations.
3D roughness standard for performance verification of topography instruments for additively-manufactured surface inspection
Authors: Jones Christopher W , Sun Wenjuan , Boulter Hal , Brown Stephen
Published: April 2022

The unique complex topography of additively-manufactured surfaces—and the recent rapid evolution of instruments and techniques to measure them—limits trust in inspection data, in direct conflict with the requirements of application areas such as aerospace, where failure of a part can have serious safety consequences. Topography instrument manufacturers and end-users require measurement standards with a controlled reproduction of representative additively-manufactured surfaces to calibrate, performance-verify and intercompare instruments for inspection tasks, thereby improving confidence in measurement. The design of such a surface texture measurement standard is reported, optimised for optical areal topography-measuring instruments and compatible with x-ray computed tomography instruments. Machined from an additively-manufactured blank, the standard’s four sides represent increasing levels of post-processing from the as-deposited surface. Datum features on the measurement standard facilitate direct comparison between topography instruments. Integrated step features support the calibration of an instrument’s Z scale. Calibration of a prototype of the standard is reported; the prototype is matched to a typical aerospace Scalmalloy™ additive manufacturing process. The calibration is also a trial application of a large-area chromatic confocal microscope; this instrument appears capable of calibrating relatively rough measurement standards if required to do so. Reference Ra and S-parameter measurements and associated measurement uncertainties are presented, correlation between parameters noted, and choice and consequences of filter settings discussed.
A smoothly tunable shape memory metamaterial with adaptive bandgaps for ultra-wide frequency spectrum vibration control
Authors: Song Yihao , Shen Yanfeng
Published: April 2022

This article presents a smoothly tunable shape memory elastic metamaterial with adaptive bandgaps enabling the broadband frequency vibration control. The underlying bandgap-tuning mechanism arises from the reversible large deformation induced by shape memory alloy (SMA) element under electro-thermal loads, through which, various microstructural shape morphing could be achieved. Via delicately designing the unit cell, the numerically obtained band structures and effective medium properties display a successful attainment of the vibration stop-passing band formation and smoothly controllable two-way tuning phenomenon for a series of transitional and intermediate status. The overall controllable frequency scope could be shifted over an ultra-wide band. Subsequently, a systematic parametric study is carried out to unfold the bandgap-adjusting patterns by altering the apparent structural stiffness and the SMA elastic modulus, individually. The finite element harmonic analysis of a metamaterial unit-cell-chain model is further investigated to verify the effectiveness of vibration suppression and the variability of the stopband region from the frequency spectra and the equivalent stresses images. Finally, the experimental demonstration is performed to validate the numerical predication from a practical perspective. The proposed design may possess enabling application potentials for future active vibration control and noise isolation in engineering facilities.
Triple-vortex bremsstrahlung
Authors: Wang W Q , Lei S H , Geng X S , Shen B F , Bu Z G , Ji L L
Published: April 2022

Particles in vortex states have gained arising interests due to the additional degree of freedom—the orbital angular momentum (OAM) inherently existing in the state. With the increasing energy of vortex particles (photons, leptons etc), the research has gradually transitioned from the classical field regime to collisions of vortex particles in the quantum-field regime. The latter provides a new way to study the rich properties of particle physics. Here, we show the characteristics of vortex states in bremsstrahlung by deriving the corresponding scattering probability following the quantum-electrodynamics theory. The theory allows us to obtain the OAM distribution of the outgoing vortex photon and the law of OAM transfer during interaction. It is shown that the generated photon takes most of the initial electron OAM, especially when the latter is more energetic. The opening angle of outgoing particles in vortex bremsstrahlung is also significantly different from plane wave scattering. The effects of polarization and non-zero impact parameter are also discussed. The results illustrate the unique feature of vortex scattering and suggest a feasible way to generate high-energy vortex photons—a novel source in studying nuclear physics.
Measuring and adjusting the distance between the center of mass and optical center of a free-falling body in an absolute gravimeter
Authors: Ye Yu , Xiang Hu , Wen-jing Shi , Zi-wei Ye , Kang Lü , Fu Bao , Ruo-lin Wang , Jin-yang Feng
Published: April 2022

In an absolute gravimeter based on optical interferometry, the rotation of a falling body leads to inaccurate gravity measurement. By arranging the center of mass (COM) of the falling body together with its optical center (OC), the rotation error can be minimized rapidly. An optical measurement system with a two-stage pendulum structure is proposed to measure the distance between the COM and the OC of the falling body. The displacement of the OC is measured by an orthogonal interferometer while the falling body twists around the torsion wire, and the rotation angle of the falling body is measured synchronously by a photoelectric autocollimator. It is proved that a twist of the falling body by 2.4 degrees leads to a significant offset of about 0.2 nm along the direction of the laser beam. This results in a limit error of the measurement of the distance between the OC and the COM less than 1 μm. Thus, the rotation error in absolute gravity measurement is reduced to 0.07 μGal.
Analytic beamformer transformation for transfer learning in motion-onset visual evoked potential decoding
Authors: Libert Arno , Van Den Kerchove Arne , Wittevrongel Benjamin , Van Hulle Marc M
Published: April 2022

Objective. While decoders of electroencephalography-based event-related potentials (ERPs) are routinely tailored to the individual user to maximize performance, developing them on populations for individual usage has proven much more challenging. We propose the analytic beamformer transformation (ABT) to extract phase and/or magnitude information from spatiotemporal ERPs in response to motion-onset stimulation. Approach. We have tested ABT on 52 motion-onset visual evoked potential (mVEP) datasets from 26 healthy subjects and compared the classification accuracy of support vector machine (SVM), spatiotemporal beamformer (stBF) and stepwise linear discriminant analysis (SWLDA) when trained on individual subjects and on a population thereof. Main results. When using phase- and combined phase/magnitude information extracted by ABT, we show significant improvements in accuracy of population-trained classifiers applied to individual users (p < 0.001). We also show that 450 epochs are needed for a correct functioning of ABT, which corresponds to 2 min of paradigm stimulation. Significance. We have shown that ABT can be used to create population-trained mVEP classifiers using a limited number of epochs. We expect this to pertain to other ERPs or synchronous stimulation paradigms, allowing for a more effective, population-based training of visual BCIs. Finally, as ABT renders recordings across subjects more structurally invariant, it could be used for transfer learning purposes in view of plug-and-play BCI applications.
A framework for quantifying the effects of transcranial magnetic stimulation on motor recovery from hemiparesis: corticomuscular network
Authors: Tan Gansheng , Wang Jixian , Liu Jinbiao , Sheng Yixuan , Xie Qing , Liu Honghai
Published: April 2022

Objective. Transcranial magnetic stimulation (TMS) is an experimental therapy for promoting motor recovery from hemiparesis. At present, hemiparesis patients’ responses to TMS are variable. To maximize its therapeutic potential, we need an approach that relates the electrophysiology of motor recovery and TMS. To this end, we propose corticomuscular network (CMN) representing the holistic motor system, including the cortico-cortical pathway, corticospinal tract, and muscle co-activation. Approach. CMN is made up of coherence between pairs of electrode signals and spatial locations of the electrodes. We associated coherence and graph features of CMN with Fugl-Meyer Assessment (FMA) for the upper extremity. Besides, we compared CMN between 8 patients with hemiparesis and 6 healthy controls and contrasted CMN of patients before and after a 1 Hz TMS. Main results. Corticomuscular coherence (CMC) correlated positively with FMA. The regression model between FMA and CMC between five pairs of channels had 0.99 adjusted and a p-value less than 0.01. Compared to healthy controls, CMN of patients tended to be a small-world network and was more interconnected with higher CMC. CMC between cortex and triceps brachii long head was higher in patients. 15 min 1 Hz TMS protocol induced coherence changes beyond the stimulation side and had a limited impact on CMN parameters that are related to motor recovery. Significance. CMN is a potential clinical approach to quantify rehabilitating progress. It also sheds light on the desirable electrophysiological effects of TMS based on which rehabilitating strategies can be optimized.
Propulsion optimization of a jellyfish-inspired robot based on a nonintrusive reduced-order model with proper orthogonal decomposition
Authors: Ying Zixiang , Zhang Haozhi , Wang Linxiang , Melnik Roderick
Published: April 2022

In this research, the propulsion of the proposed jellyfish-inspired mantle undulated propulsion robot (MUPRo) is optimized. To reliably predict the hydrodynamic forces acting on the robot, the proposed nonintrusive reduced-order model (NIROM) based on proper orthogonal decomposition (POD) additionally considers the POD basis that makes an important contribution to the features on the specified boundary. The proposed model establishes a mapping between the parameter-driven motion of the mantle and the evolution of the fluid characteristics around the swimmer. Moreover, to predict new cases where the input needs to be updated, the input of the proposed model is taken from the kinematics of the robot rather than extracted from full-order high-fidelity models. In this paper, it takes approximately 950 s to perform a simulation using the full-order high-fidelity model. However, the computational cost for one prediction with the proposed POD-NIROM is around 0.54 s, of which about 0.2 s is contributed by preprocessing. Compared with the NIROM based on the classic POD method, the proposed POD-NIROM can effectively update the input and reasonably predict the characteristics on the boundary. The analysis of the hydrodynamic performance of the MUPRo pinpoints that, over a certain period and with a certain undulation amplitude, the hydrodynamic force generated by the swinging-like mantle motion (k < 0.5) is greater, outperforming Aequorea victoria in startup acceleration. It is demonstrated that considering a certain power loss and a certain tail beat amplitude, the wave-like mantle motion (k > 0.5) can produce greater propulsion, which means higher propulsion efficiency.
Marked non-compliance with deforestation embargoes in the Brazilian Amazon
Authors: Silva Verissimo César Sousa da , Vieira Ima Celia Guimaraes , Galbraith David , Potapov Peter , Rivero Sérgio Luiz de Medeiros , Lima Aline Maria Meiguins de , Pimentel Marcia Aparecida da Silva , Adami Marcos
Published: April 2022

Advances in monitoring capacity and strengthened law enforcement have helped to reduce deforestation in the Brazilian Amazon since the early 2000s. Embargoes imposed on the use of deforested land are important instruments for deterring deforestation and enabling forest recovery. However, the extent to which landowners respect embargoes in the Brazilian Amazon is unknown. In this study, we evaluated the current recovery status of embargoes due to deforestation imposed between 2008 and 2017 to conduct the first large-scale assessment of compliance with embargo regulations. We observed forest recovery in only 13.1% (±1.1%) of embargoed polygons, while agriculture and pasture activities were maintained in 86.9% (±1.8%) of embargoed polygons. Thus, landowners openly continue to disrespect environmental legislation in the majority of embargoed areas. We attribute the marked non-compliance observed to limited monitoring of embargoed areas, as environmental agents seldom return to verify the status of embargoed lands after they have been imposed. Recent advances in remote sensing provide low-cost ways to monitor compliance and should form the basis of concerted efforts to ensure that the law is observed and that those responsible for illegal deforestation do not benefit from it.
The tight-focusing properties of radially polarized symmetrical power-exponent-phase vortex beam
Authors: Chen Kang , Ma Zhiyuan , Zhang Mingming , Dou Jiantai , Hu Youyou
Published: April 2022

In this paper, the radially polarized (RP) new kind of power-exponent-phase vortex (NPEPV) beam, with rotationally symmetrical phase structure, was introduced and the tightly focused properties of the RP NPEPV beam passing through a high numerical aperture objective lens were studied numerically. The results show that with the increase of topological charge l, there are multiple intensity points in the focal region, and the number is consistent with the topological charge. In addition, as the power order n increases, the light intensity gradually concentrates on the central optical axis and the surrounding intensity points gradually disappear, which finally presents a Gaussian intensity distribution with the dark cores gradually move away from the optical axis and disappear. These unique properties will have potential applications in particle trapping and laser fabrication, especially for simultaneous trapping of multiple particles and fabrication of chiral microstructures.
Machine learning assisted insights into the mechanical strength of nanocrystalline graphene oxide
Authors: Xu Yihua , Shi Qiao , Zhou Ziyue , Xu Ke , Lin Yanwen , Li Yang , Zhang Zhisen , Wu Jianyang
Published: April 2022

The mechanical properties of graphene oxides (GOs) are of great importance for their practical applications. Herein, extensive first-principles-based ReaxFF molecular dynamics (MD) simulations predict the wrinkling morphology and mechanical properties of nanocrystalline GOs (NCGOs), with intricate effects of grain size, oxidation, hydroxylation, epoxidation, grain boundary (GB) hydroxylation, GB epoxidation, GB oxidation being considered. NCGOs show brittle failures initiating at GBs, obeying the weakest link principle. By training the MD data, four machine learning models are developed with capability in estimating the tensile strength of NCGOs, with sorting as eXtreme Gradient Boosting (XGboost) > multilayer perceptron > gradient boosting decision tree > random forest. In the XGboot model, it is revealed that the strength of NCGOs is greatly dictated by oxidation and grain size, and the hydroxyl group plays more critical role in the strength of NCGOs than the epoxy group. These results uncover the pivotal roles of structural signatures in the mechanical strength of NCGOs, and provide critical guidance for mechanical designs of chemically-functionalized nanostructures.
Comparison of interfaces, band alignments, and tunneling currents between crystalline and amorphous silica in Si/SiO2/Si structures
Authors: Ko Eunjung , Choi Jung-Hae
Published: April 2022

Recently, to improve the performance of an integrated metal-oxide-semiconductor (MOS) device, an attempt has been made in the industry to replace the amorphous oxide with a crystalline oxide. However, various characteristics caused by the difference between amorphous and crystalline oxide in the MOS structure have not been systematically investigated. Therefore, we demonstrate the difference in atomic interface structures, electronic structures, and tunneling properties concerning varied oxide phases in a representative system, Si/SiO2/Si structures, with sub-3 nm-thick silica from first-principles. We investigate two oxide phases of amorphous (a-) and crystalline (c-) SiO2 with and without H passivation at the interface. Si/a-SiO2 exhibits a smooth interface layer, whereas Si/c-SiO2 exhibits an abrupt interface layer, resulting in the thicker interface layer of Si/a-SiO2 than Si/c-SiO2. Thus for a given total silica thickness, the adequate tunneling-blocking thickness, where all the Si atoms form four Si–O bonds, is thinner in a-SiO2 than c-SiO2, originating more tunneling current through a-SiO2 than c-SiO2. However, the effects of dangling bonds at Si/c-SiO2 rather than Si/a-SiO2 on tunneling currents are crucial, particularly in valence bands. Furthermore, when the dangling bonds are excluded by H atoms at Si/c-SiO2, the tunneling current dramatically reduces, whereas the H-passivation effect on the tunneling blocking at Si/a-SiO2 is insignificant. Our study contributes systematic knowledge regarding oxide phases and interfaces to promote for high performance of MOS devices.
Quantification of Ephedrine Substances in Human Urine by Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry
Authors: Wang Yunfei , Yan Kuan , Wang Zhanliang , He Genye , Chang Wei
Published: April 2022

An accurate quantitative method for four prohibited ephedrine substances in human urine has been established, based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS). The quantitative bias caused by pretreatment operations and matrix effects was reduced by the dilute and shoot pretreatment method. The good separation of isomers was achieved with the advantages of the UPLC instrument and Agilent Poroshell 120 EC-C8 UPLC column. Stable quantitative ions were selected during the analysis with MS/MS. The result of the method validation experiment showed an excellent linearity between 50% and 200% threshold concentration with a correlation coefficient (r2) greater than 0.999. The coefficient of variation at the limit of quantification and threshold was <20% and 10%, respectively. The uncertainty was below the maximum uncertainty specified in the technical document of the World Anti-Doping Agency (WADA). The analytical result using this method has passed the WADA-external quality assessment scheme. The anti-doping laboratory has applied the method in routine tests and reported adverse analytical finding.
Gender-Based Differences in Response to Tumor Necrosis Factor Inhibitor Therapies for Ulcerative Colitis: Individual Participant Data Meta-Analyses of Clinical Trials
Authors: Agrawal Manasi , Petralia Francesca , Tepler Adam , Durbin Laura , Reinisch Walter , Colombel Jean-Frederic , Shah Shailja C
Published: April 2022

Background

Gender-based differences are reported in inflammatory bowel diseases (IBD) pathogenesis, but their impacts on IBD outcomes are not well known. We determined gender-based differences in response to treatment with tumor necrosis factor inhibitor (TNFi) therapies in individuals with ulcerative colitis (UC).

Methods

We used the Yale University Open Data Access (YODA) platform to abstract individual participant data from randomized clinical trials to study infliximab and golimumab as induction and maintenance therapies in moderately to severely active UC. Using multivariable logistic regression, we examined associations between gender and the endpoints of clinical remission, mucosal healing, and clinical response for each study individually and in a meta-analysis.

Results

Of 1639 patients included in induction trials (Program of Ulcerative Colitis Research Studies Utilizing an Investigational Treatment—Subcutaneous [PURSUIT-SC], active ulcerative colitis trials [ACT] 1 and 2) and 1280 patients included in maintenance trials (Program of Ulcerative Colitis Research Studies Utilizing an Investigational Treatment—Maintenance [PURSUIT-IM], ACT 1 and 2), 696 (42.5%) and 534 (41.7%) were women, respectively. In a meta-analysis of induction trials, the adjusted odds ratios (aORs) of clinical remission (aOR, 0.55; 95% CI, 0.31–0.97), mucosal healing (aOR, 0.47; 95% CI, 0.27–0.83), and clinical response (aOR, 0.51; 95% CI, 0.29–0.90) in the treatment arm and of clinical remission in the placebo arm (aOR, 0.34; 95% CI, 0.15–0.82) were lower in men compared to women. There were no differences in outcomes by gender in the treatment and placebo arms in the meta-analysis of maintenance trials.

Conclusions

Men are less likely to achieve clinical remission, mucosal healing, and clinical response compared to women during induction treatment with TNFi for UC, but not during the maintenance phase. Future studies delineating the mechanisms underlying these observations would be informative.
Loss of Consciousness and Visual Hallucinations Related to 5-MeO-DALT Intake, a Case Report Confirmed by Toxicological Analyses
Authors: Dufayet Laurène , Langrand Jérôme , Alvarez Jean-Claude , Islam Larabi Amine
Published: April 2022

5-MeO-DALT or 5-methoxy-N,N-diallyltryptamine is a derivative of tryptamines, consumed for its hallucinogenic and entheogenic effects. We report the case of a 46-year-old-man, presenting with a brief loss of consciousness and visual hallucinations, after the consumption of three 5-MeO-DALT tablets bought online. Liquid chromatography coupled to tandem mass spectrometry method was performed, and 5-MeO-DALT was quantified in both the tablets (32.5 mg per tablet, 11% of purity) and the patient’s plasma (7 ng/mL—8 h between the consumption and the blood sample). 5-MeO-DALT poisonings are rarely described. Given the broad availability of these products, it is important that emergency department physicians and clinical toxicologists do not overlook the possibility of the ingestion of recreational tryptamines, especially since they are not detected by most routine toxicological screening.
Structural implications of potential field data on Southeastern North America
Authors: Alarifi Saad S
Published: April 2022

The fault system of Eastern Piedmont could be extensive in the East of the USA. Debates remain regarding the sutures zone, contacts and faults between terranes, especially underneath the coastal sediment. However, in this study, a new interpretation of the structures and contacts of the southeastern margin was based on regional land gravity anomaly and magnetic anomaly maps. To delineate and investigate the subsurface geological structures in the southern Appalachian belt and underneath the coastal sediment that covers the southeastern half of the study area, the gravity and magnetic maps were subjected to several filter techniques. The anomalies maps were enhanced by applying the reduction to pole (RTP), analytical signal (AS), tilt derivative (TDR), horizontal gradient (HG), direction filter and power spectrum techniques. The power spectrum filter was applied to separate the regional-residual anomaly. The results of regional anomaly maps display elongate high amplitude anomalies lie in the south that are related to deep-seated igneous mafic intrusive and basaltic lavas emplacement. The directional filter was used to eliminate the sutural trend of the Jurassic dikes that intruded the study area. The result displays the structural contacts clearly after removing the anomalies of the Jurassic. Finally, the edge detection filters (TDR, HG, AS) from the gravity and magnetic maps helped in mapping the anomaly contact of the subsurface bodies. The apparent structural signature of the interpreted contacts confirmed the presence of these structural features in all edge detection methods.
Factors Influencing Family Woodland Management Action After Calling a Public Agency Forester
Authors: Sagor Eli S , Sebald Martha J , Kilgore Michael A , Blinn Charles R , Snyder Stephanie A , Russell Matthew B
Published: April 2022

Many public agencies make foresters available to answer landowners’ land management questions. We gathered data about landowner calls to private forest management (PFM) foresters employed by a Minnesota state agency in 2017 and 2018. We used a mailed questionnaire to assess the outcomes of these contacts, including land management actions taken and factors most influential the landowner’s subsequent decision process. The most common topic landowners called about was enrolling in a property tax program, followed by harvesting and planting trees, obtaining financial assistance, and controlling forest pests. Eighteen months after the initial call, implementation rates and intent were high, ranging from 73%–91%. Across management actions, information from a PFM forester, likelihood of timely implementation, and expected benefit were highly influential. PFM calls also informed landowners about additional land management actions, many of which they implemented. Our results offer new insight into the value of landowner contact with public sector foresters.
Experimental study on erosion and wear law of metal screen under spraying condition
Authors: Ying Ruomeng , Zhao Xuankang , Shi Baocheng , Wu Lijuan , Zhang Xingkai , Jiang Ziheng , Guo Xiaochi
Published: April 2022

It is very important for the safe production of sand producing oil and gas wells to make clear the erosion law of sand control screen pipe. The experiment of erosion law of metal mesh under two working conditions of blockage and non-blockage was carried out with jet erosion experimental device. The influencing factor of solid mass fraction (0.3%, 0.5%, and 0.8%), aperture velocity (1.5 m/s, 4 m/s, and 6 m/s) and particle size (20 μm, 54 μm, and 74 μm) on the erosion rate of metal mesh was analyzed. The results show that the mass loss of screen increases with the increase of solid mass fraction, aperture velocity and particle size, and the change law of single and double screens is consistent; under the condition of incomplete blockage, the mass loss of screen increases exponentially with the flow rate; under the condition of complete blockage, the balance flow rate of screen decreases with the increase of pressure difference when the pressure difference between inlet and outlet of screen is kept constant. In addition, the mass loss increases with the increase of pressure difference; in addition, the scanning electron microscope results of the erosion screen show that the erosion wear of the screen under the non-blocking condition is much less than that under the blocking condition, which is because the gap between the weft wires of the screen is blocked by particles, resulting in the rapid increase of the local aperture velocity of the screen, thus accelerating the local erosion wear of the screen.
Scattering of a scalene trapezoidal hill with a shallow cavity to SH waves
Authors: Sun Yingchao , Yang Zailin , Chen Lei , Mao Duanhua
Published: April 2022

Both surface ground motion and cavity stress concentration have always been considered in the designs of earthquake engineering. In this paper, a theoretical approach is used to study the scattering problem of circular holes under a scalene trapezoidal hill. The wave displacement function was obtained by solving the Helmholtz equation that meets the zero-stress boundary conditions by the variable separation method and the image method. Based on the complex function, the multipolar coordinate method and the region-matching technique, algebraic equations were established at auxiliary boundaries and free boundary conditions in the complex domain. Auxiliary circles were used to solve the singularity of the reflex angle at the trapezoidal corner. Then, according to the sample statistics, instead of the Fourier expansion method, the least-squares method was used to solve the undetermined coefficient of the algebraic equations by discrete boundaries. Frequency responses for some parameters were calculated and discussed. The numerical results demonstrate that the continuity of the auxiliary boundaries and the accuracy of the zero-stress boundary are good; the displacement of the free surface and the stress of the circular hole are related to the shape of the trapezoid, the position of the circular hole, the direction of the incident wave and the frequency content of the excitation. Finally, time-domain responses were calculated by inverse fast Fourier transform based on the frequency domain theory, and the results have revealed the wave propagation mechanism in the complicated structure.
Weight functions for an array of collinear cracks in an infinite anisotropic elastic plate
Authors: Wu Kuang-Chong , Chen Shyh-Haur
Published: April 2022

Weight functions are provided for calculating the stress intensity factors for collinear cracks in an infinite anisotropic elastic plate. The number of cracks as well as the length of the cracks are arbitrary. The weight functions are for crack-face loading, which may be non-self-equilibrium. It is shown that for self-equilibrium loading, the weight functions are independent of elastic constants. For non-self-equilibrium loading, however, an additional constant term that is material-dependent appears.
Integrity Demands It
Authors: Waller Stephen G
Published: April 2022

Global Health Engagements can be more effective if better evaluation is done and if both line and diplomatic leaders are better educated by deploying medical personnel. To achieve better outcomes, these tasks should be a high priority for global health engagements. Integrity demands it.
Integrated safety analysis of filgotinib treatment for rheumatoid arthritis in patients from Japan over a median of 1.5 years
Authors: Ishiguro Naoki , Tanaka Yoshiya , Matsubara Tsukasa , Atsumi Tatsuya , Amano Koichi , Sugiyama Eiji , Yamaoka Kunihiro , Winthrop Kevin , Kivitz Alan , Burmester Gerd R , Gottenberg Jacques-Eric , Genovese Mark C , Matzkies Franziska , Guo Ying , Jiang Deyuan , Bartok Beatrix , Pechonkina Alena , Kondo Akira , Besuyen Robin , Takeuchi Tsutomu
Published: April 2022

Objective

Characterize safety of the Janus kinase-1 preferential inhibitor filgotinib (FIL) in Japanese patients with moderately to severely active rheumatoid arthritis (RA).

Methods

Data from three Phase 3 trials (NCT02889796, NCT02873936, and NCT02886728) and a long-term extension (NCT03025308) through September 2019 were integrated; patients received ≥1 dose of FIL 200 (FIL200) or 100 mg (FIL100) daily, or placebo (PBO). We calculated exposure-adjusted incidence rates (EAIRs) per 100 patient-years FIL exposure (100PYE) for treatment-emergent adverse events (TEAEs) and adverse events of special interest.

Results

Among 3691 total patients and 6080.7 PYE, 229 Japanese patients received FIL for 311.4 PYE (median 1.5, maximum 2.5 years). During the 12-week PBO-controlled period, serious TEAEs and TEAEs leading to study drug disruption were comparable between FIL and PBO. Serious infection rates were 1.9%, 0%, and 2% for FIL200, FIL100, and PBO during the PBO-controlled period; long-term FIL200 and FIL100 EAIRs were 3.8 and 2.1/100PYE. No herpes zoster (HZ) or major adverse cardiovascular events (MACEs) occurred during the PBO-controlled period; long-term FIL200 and FIL100 EAIRs were 3.0 and 2.1/100PYE (HZ) and 0.6 and 0/100PYE (MACE).

Conclusion

Long-term FIL treatment (median 1.5, maximum 2.5 years exposure) was well tolerated at 100- and 200-mg doses in Japanese patients with RA.