bluuebunny/crossref_metadata_2025 huggingface dataset:
Network pharmacology and molecular docking study on the active ingredients of qidengmingmu capsule for the treatment of diabetic retinopathy
Authors: Zhang Mingxu , Yang Jiawei , Zhao Xiulan , Zhao Ying , Zhu Siquan
Published: April 2021

Diabetic retinopathy (DR) is a leading cause of irreversible blindness globally. Qidengmingmu Capsule (QC) is a Chinese patent medicine used to treat DR, but the molecular mechanism of the treatment remains unknown. In this study, we identified and validated potential molecular mechanisms involved in the treatment of DR with QC via network pharmacology and molecular docking methods. The results of Ingredient-DR Target Network showed that 134 common targets and 20 active ingredients of QC were involved. According to the results of enrichment analysis, 2307 biological processes and 40 pathways were related to the treatment effects. Most of these processes and pathways were important for cell survival and were associated with many key factors in DR, such as vascular endothelial growth factor-A (VEGFA), hypoxia-inducible factor-1A (HIF-1Α), and tumor necrosis factor-α (TNFα). Based on the results of the PPI network and KEGG enrichment analyses, we selected AKT1, HIF-1α, VEGFA, TNFα and their corresponding active ingredients for molecular docking. According to the molecular docking results, several key targets of DR (including AKT1, HIF-1α, VEGFA, and TNFα) can form stable bonds with the corresponding active ingredients of QC. In conclusion, through network pharmacology methods, we found that potential biological mechanisms involved in the alleviation of DR by QC are related to multiple biological processes and signaling pathways. The molecular docking results also provide us with sound directions for further experiments.
Author Correction: Quantitative material analysis using secondary electron energy spectromicroscopy
Authors: Han W. , Zheng M. , Banerjee A. , Luo Y. Z. , Shen L. , Khursheed A.
Published: April 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Maternal folic acid supplementation prevents autistic behaviors in a rat model induced by prenatal exposure to valproic acid
Authors: Di Yuanyuan , Li Zhongqi , Li Jin , Cheng Qiangqiang , Zheng Qi , Zhai Chenyang , Kang Mengsi , Wei Chunling , Lan Jijun , Fan Juan , Ren Wei , Tian Yingfang
Published: April 2021

Maternal FA supplementation at 4 mg kg−1 rescued the development delay, anxiety and core autism-like behaviors, and restored the abnormal synaptic spine morphology and synaptic protein expression in mPFC in the male offspring prenatally exposed to VPA.
Imaging margins of skin tumors using laser-induced breakdown spectroscopy and machine learning
Authors: Kiss Kateřina , Šindelářová Anna , Krbal Lukáš , Stejskal Václav , Mrázová Kristýna , Vrábel Jakub , Kaška Milan , Modlitbová Pavlína , Pořízka Pavel , Kaiser Jozef
Published: April 2021

Nowadays, laser-based techniques play a significant role in medicine, mainly in the ophthalmology, dermatology, and surgical fields.
Nonvolatile resistive switching and synaptic characteristics of lead-free all-inorganic perovskite-based flexible memristive devices for neuromorphic systems
Authors: Siddik Abubakkar , Haldar Prabir Kumar , Paul Tufan , Das Ujjal , Barman Arabinda , Roy Asim , Sarkar Pranab Kumar
Published: April 2021

Recently, several types of lead halide perovskites have been actively researched for resistive switching memory or artificial synapse due to their current–voltage hysteresis along with the feasibility of fabrication and superior charge mobility.
pH-Triggered nanoreactors as oxidative stress amplifiers for combating multidrug-resistant biofilms
Authors: Huang Lei , Jiang Shangming , Cai Bo , Wang Guobin , Wang Zheng , Wang Lin
Published: April 2021

Developing radical oxygen species (ROS)-generating nanoreactors as new “antibiotics” is a promising strategy for the treatment of multidrug-resistant (MDR) biofilm infections.
Calcium-induced reversible assembly of phosphorylated amphiphile within lipid bilayer membranes
Authors: Shimizu Yusuke , Sato Kohei , Kinbara Kazushi
Published: April 2021

A phosphorylated amphiphile assembles and disassembles reversibly within lipid bilayer membranes upon sequential addition of calcium chloride and ethylenediaminetetraacetic acid.
Molecular dynamics simulations demonstrate that non-ideal mixing dominates subsaturation organic aerosol hygroscopicity
Authors: Roston Daniel
Published: April 2021

MD simulations compute the free energy of adding water to aerosols, showing that non-ideal mixing dominates hygroscopicity at low humidity.
Using nanoselenium to combat Minamata disease in rats: the regulation of gut microbes
Authors: Liu Yang , Zhang Wei , Zhao Jiating , Lin Xiaoying , Wang Liming , Cui Liwei , Zhang Junfang , Li Bai , Li Yu-Feng
Published: April 2021

Nanoselenium promoted demethylation of methylmercury and regulated gut microbes in methylmercury-poisoned rats.
Why conductivity is not always king – physical properties governing the capacitance of 2D metal–organic framework-based EDLC supercapacitor electrodes: a Ni3(HITP)2 case study
Authors: Borysiewicz Michał Adam , Dou Jin-Hu , Stassen Ivo , Dincă Mircea
Published: April 2021

The physical properties of the 2D MOF Ni3(HITP)2 synthesized in batches under different conditions are analysed to understand which variables govern the capacitive behaviour of supercapacitor electrodes prepared using the neat MOF material.
Electrosynthesis of functionalized tetrahydrocarbazolesviasulfonylation triggered cyclization reaction of indole derivatives
Authors: Yin Zizhen , Yu Yingjie , Mei Haibo , Han Jianlin
Published: April 2021

An efficient method to synthesize functionalized tetrahydrocarbazolesviaradical electrochemical oxidative sulfonylation/cyclization reaction between indole derivatives and sodium sulfinates has been developed.
Coupling fluid flow to hydrogel fluidic devices with reversible “pop-it” connections
Authors: Abbasi Reha , LeFevre Thomas B. , Benjamin Aaron D. , Thornton Isaak J. , Wilking James N.
Published: April 2021

Here, we describe a simple, reversible, plug-based connector designed to couple microfluidic tubing to a hydrogel-based fluidic device, to allow for pressurized liquid flow through the system.
A3Mn2Sb3S8(A = K and Rb): a new type of multifunctional infrared nonlinear optical material based on unique three-dimensional open frameworks
Authors: Xiao Yu , Chen Man-Man , Shen Ya-Ying , Liu Peng-Fei , Lin Hua , Liu Yi
Published: April 2021

A new type of multifunctional IR-NLO material, A3Mn2Sb3S8(A = K and Rb), with unique 3D open frameworks has been developed using a facile surfactant–thermal method.
Recent advances in NHC–palladium catalysis for alkyne chemistry: versatile synthesis and applications
Authors: Li Jianxiao , He Dan , Lin Zidong , Wu Wanqing , Jiang Huanfeng
Published: April 2021

This review summarizes the recent developments in NHC–palladium catalysis for alkyne chemistry: versatile synthesis and applications.
C(sp3)–H functionalization with isocyanides
Authors: Wang Weixiang , Liu Tianqi , Ding Chang-Hua , Xu Bin
Published: April 2021

This review highlights the state-of-the-art advances in C(sp3)–H functionalization involving isocyanides through the synergistic combination of isocyanide insertion and C(sp3)–H bond activation.
Copper-catalyzed Beckmann-type fragmentation of less-strained cycloketoxime esters
Authors: Zhao Binlin , Zheng Yukun , Chen Cheng , Wang Mengning , Ma Mengtao , Shi Zhuangzhi
Published: April 2021

We have developed a modular, convenient and practical copper-catalyzed platform for the preparation of alkene nitriles from corresponding cycloketoxime estersviaradical-mediated C–C bond cleavage.
Lewis acid-catalyzed regioselective C–H carboxamidation of indolizines with dioxazolonesviaan acyl nitrene type rearrangement
Authors: Song Dan , Huang Changfeng , Liang Peishi , Zhu Baofu , Liu Xiang , Cao Hua
Published: April 2021

An efficient, direct, and novel Lewis acid-catalyzed regioselective C–H carboxamidation of indolizines with dioxazolonesviaan acyl nitrene type rearrangement under metal-free conditions has been documented.
Microsecond timescale MD simulations at the transition state of PmHMGR predict remote allosteric residues
Authors: Quinn Taylor R. , Steussy Calvin N. , Haines Brandon E. , Lei Jinping , Wang Wei , Sheong Fu Kit , Stauffacher Cynthia V. , Huang Xuhui , Norrby Per-Ola , Helquist Paul , Wiest Olaf
Published: April 2021

Transition state force fields enable MD simulations at the transition state of HMGCoA reductase that sample the transition state ensemble on the μs timescale to identify remote residues that affect the reaction rate.
Material-assisted mass spectrometric analysis of low molecular weight compounds for biomedical applications
Authors: Kulkarni Anuja Shreeram , Huang Lin , Qian Kun
Published: April 2021

This comprehensive review highlights the recent research on a material-assisted mass spectrometric analysis of low molecular weight compounds, including material types, material preparation approaches, and biomedical applications.
Evaluation of the measurement uncertainty of the stiffness modulus: test case of indirect tensile on cylindrical specimens
Authors: Mezouara Hicham , Dlimi Latifa , Salih Abdelouahhab , Afechcar Mohamed , Zniker Houcine
Published: April 2021

This study treats the measurement uncertainties that we can find in the stiffness modulus of the bituminous test. We present all the sensors installed on rigidity modulus measurement chains and also their uncertainty ranges. Several parameters influence the rigidity module's value, such as the parameters related to experimental conditions, and others are rather connected to the equipment's specification, which are the speed, the loading level, the temperature, the tested sample dimension, and the data acquisition, etc. All these factors have a great influence on the value of the modulus of rigidity. To qualify the uncertainty factors, we used two approaches: the first one is made by following the method described by the GUM (Guide to the expression of uncertainty in measurement), the second approach based on the numerical simulation of the Monte Carlo. The two results are then compared for an interval of confidence of 95%. The paper also shows the employment of the basic methods of statistical analysis, such as the Comparing of two variances. Essential concepts in measurement uncertainty have been compiled and the determination of the stiffness module parameters are discussed. It has been demonstrated that the biggest source of error in the stiffness modulus measuring process is the repeatability has a contribution of around 45.23%.
The Hill We Climb
Authors: Holzhauer Peter
Published: April 2021

„When day comes we ask ourselves, where can we find light in this never ending shade”?

Die Welt ächzt unter einer nun schon einem Jahr andauernden Pandemie, die auch in unserem Land zahlreiche Opfer gefordert hat. Allein die Vereinigten Staaten von Amerika haben fast eine halbe Million Todesfälle als Opfer der Pandemie zu beklagen. Gleichzeitig gibt es neue Hoffnung auf Besserung durch politischen Wandel. Amerika, die ganze Welt und auch die Umwelt, der Garant für unser (Über)leben, waren in letzter Zeit nicht nur durch dieses Virus bedroht, sondern auch durch eine sich viral verbreitende Botschaft der Ignoranz, des Populismus und der Polemik sowie Rassismus und ökologischem Nihilismus.
Ein langer Weg: metastasierendes Pankreaskarzinom/COVID-19-Infektion und protrahiertes Fatigue-Syndrom
Authors: Holzhauer Peter
Published: April 2021

Der lange Behandlungsverlauf einer 78-jährigen Patientin mit einem schon bei Erstdiagnose diffus hepatisch metastasierten Pankreaskarzinom wird – mit besonderem Fokus auf unerwünschte Begleiterscheinungen von Therapie und Krankheit – in dieser Kasuistik vorgestellt. Die Patientin leidet schon seit Diagnosestellung an einem ausgeprägten Fatigue-Syndrom, das den privaten als auch den selbstständigen beruflichen Alltag belastet. Im Vordergrund der klinischen Symptomatik stehen körperliche Erschöpfung und kognitive Einschränkungen wie Konzentrationsstörungen. Neben der Schilderung des Krankheits- und Behandlungsverlaufs werden begleitende supportive Behandlungselemente beschrieben.
Convergent Synthesis of Angiotensin II Receptor Blockers through C–H Arylation of 1-Benzyl-5-phenyl-1H-tetrazole with Functionalized Aryl Bromides
Authors: Seki Masahiko , Takahashi Yusuke
Published: April 2021

Highly convergent synthesis of angiotensin II receptor blockers has been accomplished by means of late-stage C–H arylation using functionalized aryl bromides. C–H arylation of 1-benzyl-5-phenyl-1H-tetrazole with aryl bromides carrying methyl 2-ethoxybenzimidazole-7-carboxylate unexpectedly provided coupling products where ethyl group was migrated from oxygen to nitrogen atom. The O-to-N ethyl migration was completely suppressed by the use of N-pivaloyl-l-valine rather than the combined use of triphenylphosphine and sodium mesitylenesulfonate to result in the preferential formation of a key intermediate of candesartan cilexetil. In contrast, when an aryl bromide having ethyl 4-(1-hydroxy-1-methylethyl)-2-propylimidazole-5-carboxylate was employed, the C–H arylation proceeded smoothly to provide a late-stage intermediate, which rapidly led to olmesartan medoxomil in 3 steps.
Minimally Invasive Triple Therapy of the Presurgical Neck
Authors: DeJoseph Louis , Hojjat Houmehr , Daraei Paul Pedram
Published: April 2021

Minimally invasive in-office procedures are a fast growing field in plastic surgery. Patients often notice and complain about their neck at an earlier age. Modern treatments for the aging neck have continued to evolve over the past decade, with more options continuing to become available. In this article, we describe our noninvasive approach to the aging neck through the combination of submental liposuction, radiofrequency (RF) microneedling, and percutaneous RF as a safe and effective option. Through appropriate patient selection, preoperative counseling, and good surgical technique, appropriate results can be achieved with minimal downtime. Patient selection, counseling, appropriate anesthesia, procedure details, and results are discussed in this article.
Hemorrhagic Epidermoid Cyst in Cerebellar Vermis: Case Report and Review of the Literature
Authors: Kozák Ján , Šurkala Jozef , Novotný Martin , Švajdler Marián
Published: April 2021

Intracranial epidermoid cysts are slow growing congenital avascular neoplasms that spread across the basal surface of the brain. They most commonly occur in the paramedial region in the cerebellopontine angle and the parasellar region. Despite its generally benign nature, sporadically they can be accompanied with hemorrhage or very rarely undergo malignant transformation. The authors present a case report of a patient with a hemorrhagic vermian epidermoid cyst and a review of all published similar cases.
Tomography method employed for detecting early stages of osteoarthritis
Authors: Lim Alane
Published: April 2021

A method for detecting cartilage degradation within the body uses noninvasive technique.
Visibility-graphlet approach to the output series of a Hodgkin–Huxley neuron
Authors: Zhao Yuanying , Gu Changgui , Yang Huijie
Published: April 2021

The output signals of neurons that are exposed to external stimuli are of great importance for brain functionality. Traditional time-series analysis methods have provided encouraging results; however, the associated patterns and their correlations in the output signals of neurons are masked by statistical procedures. Here, graphlets are employed to extract the local temporal patterns and the transitions between them from the output signals when neurons are exposed to external stimuli with selected stimulating periods. A transition network is defined where the node is the graphlet and the direct link is the transition between two successive graphlets. The transition-network structure is affected by the simulating periods. When the stimulating period moves close to an integer multiple of the neuronal intrinsic period, only the backbone or core survives, while the other linkages disappear. Interestingly, the size of the backbone (number of nodes) equals the multiple. The transition-network structure is conservative within each stimulating region, which is defined as the range between two successive integer multiples. Nevertheless, the backbone or detailed structure is significantly altered between different stimulating regions. This alternation is induced primarily from a total of 12 active linkages. Hence, the transition network shows the structure of cross correlations in the output time-series for a single neuron.
The well-posedness, blow-up, and traveling waves for a two-component Fornberg–Whitham system
Authors: Xu Fei , Zhang Yong , Li Fengquan
Published: April 2021

In this paper, the two-component Fornberg–Whitham system is studied. We first investigate the local well-posedness in classical Sobolev space and establish a blow-up criterion by a local-in-time priori estimate, and then, we give some sufficient conditions on the initial data to lead to wave breaking. Finally, we discuss analytically the existence of periodic traveling waves by the bifurcation theorem.
Determination of calibration parameters of cantilevers of arbitrary shape by finite element analysis
Authors: Rodriguez-Ramos Jorge , Rico Felix
Published: April 2021

The use of atomic force microscopy in nanomechanical measurements requires accurate calibration of the cantilever’s spring constant (kc) and the optical lever sensitivity (OLS). The thermal method, based on the cantilever’s thermal fluctuations in fluids, allows estimation of kc in a fast, non-invasive mode. However, differences in the cantilever geometry and mounting angle require the knowledge of three correction factors to get a good estimation of kc: the contribution of the oscillation mode to the total amplitude, the shape difference between the free and end-loaded configurations, and the tilt of the cantilever with respect to the measured surface. While the correction factors for traditional rectangular and V-shaped cantilever geometries have been reported, they must be determined for cantilevers with non-traditional geometries and large tips. Here, we develop a method based on finite element analysis to estimate the correction factors of cantilevers with arbitrary geometry and tip dimensions. The method relies on the numerical computation of the effective cantilever mass. The use of the correction factor for rectangular geometries in our model cantilever (PFQNM-LC) will lead to values underestimated by 16%. In contrast, experiments using pre-calibrated cantilevers revealed a maximum uncertainty below 5% in the estimation of the OLS, verifying our approach.
Optimized multi-exposure optical path with a single laser pulse for the measurement of ultra-high speed
Authors: Wang Cunhong , Liu Cong , Zhang Xingyi
Published: April 2021

High-speed measurements, particularly close to the velocity of light, have always been a great challenge in the field of experimental measurement. Although traditional high-speed measurement methods based on imaging technology can achieve millions of frames per second, they face the problem that the field of view decreases with an increase in the frame rate, which is difficult to overcome in a short period. In this study, a closed multi-exposure optical path is designed first based on a 600 ps pulse laser that realizes the continuous measurement of sub-light velocity and is not subject to the field of view. The path can also be adjusted with respect to time, accurate up to sub-nanoseconds. Second, it is found that the accuracy and resolution of the present method are related to the used pulse laser and camera. Once the performances of the pulse laser and the camera are improved, the corresponding range of measurement of the velocity can be improved further. Compared with traditional pumping technologies, the proposed technology achieves continuous velocity measurement with the utilization rate of laser energy as high as 100%. Finally, we use this novel optical system to determine the flux avalanche velocity of the YBa2Cu3O7-x superconducting thin film, and a highest speed of 323.5 Km/s is obtained.
Acoustic levitation of a Mie sphere using a 2D transducer array
Authors: Zehnter Sebastian , Andrade Marco A. B. , Ament Christoph
Published: April 2021

Most acoustic levitation techniques are limited to objects smaller than half the wavelength. To overcome this limit, different strategies have been proposed for suspending macroscopic objects in mid-air. Two approaches to levitate spherical and non-spherical macroscopic objects have been recently presented: the acoustical virtual vortices and the boundary hologram method. However, the former approach places high demands on the available hardware due to the mandatory high switching rate while the latter uses a computationally expensive model that prevents future real-time manipulation. In the present work, we demonstrate the single-beam levitation of a Mie sphere using a 2D transducer array. To achieve this, we employ a computationally fast sound field model based on spherical harmonics expansion. To obtain a suitable array output, we formulate an optimization problem that maximizes the stability of the sphere while keeping the net force balanced. In addition, we prove the local asymptotic stability for the equilibrium position and determine a domain of attraction using Lyapunov-based methods. In experiments, we show that the macroscopic sphere is stably levitated in a twin tuning forks trap, which results from a superposition of two twin trap signatures and a bottle trap signature. This result could open up the possibility of a computationally fast and convenient non-contact manipulation of macroscopic objects by a superposition of holographic elements in future applications.
Constructive expansion for vector field theories I. Quartic models in low dimensions
Authors: Erbin Harold , Lahoche Vincent , Tamaazousti Mohamed
Published: April 2021

This paper is the first of a series aiming to use the loop vertex expansion (LVE) to recover or prove analyticity and Borel summability for generic vector models with bosonic or fermionic statistics in various dimensions. We consider both non-relativistic and relativistic bosons and fermions coupled with a constant quartic tensor in zero-, one-, and two-dimensional space by limiting our investigations to the super-renormalizable models. This offers a unified perspective on classical constructive results, highlighting the usefulness of the LVE as a modern tool to address these questions and to tackle more challenging models in higher dimensions. Finally, we investigate the large N and massless limits along with quenching for fermions in one dimension. In particular, this work establishes the Borel summability of the Sachdev–Ye–Kitaev model.
Epitaxial ferroelectric oxides on silicon with perspectives for future device applications
Authors: Spreitzer Matjaž , Klement Dejan , Parkelj Potočnik Tjaša , Trstenjak Urška , Jovanović Zoran , Nguyen Minh Duc , Yuan Huiyu , ten Elshof Johan Evert , Houwman Evert , Koster Gertjan , Rijnders Guus , Fompeyrine Jean , Kornblum Lior , Fenning David P. , Liang Yunting , Tong Wen-Yi , Ghosez Philippe
Published: April 2021

Functional oxides on silicon have been the subject of in-depth research for more than 20 years. Much of this research has been focused on the quality of the integration of materials due to their intrinsic thermodynamic incompatibility, which has hindered the flourishing of the field of research. Nevertheless, growth of epitaxial transition metal oxides on silicon with a sharp interface has been achieved by elaborated kinetically controlled sequential deposition while the crystalline quality of different functional oxides has been considerably improved. In this Research Update, we focus on three applications in which epitaxial ferroelectric oxides on silicon are at the forefront, and in each of these applications, other aspects of the integration of materials play an important role. These are the fields of piezoelectric microelectromechanical system devices, electro-optical components, and catalysis. The overview is supported by a brief analysis of the synthesis processes that enable epitaxial growth of oxides on silicon. This Research Update concludes with a theoretical description of the interfaces and the possibility of manipulating their electronic structure to achieve the desired coupling between (ferroelectric) oxides and semiconductors, which opens up a remarkable perspective for many advanced applications.
Compact spin qubits using the common gate structure of fin field-effect transistors
Authors: Tanamoto Tetsufumi , Ono Keiji
Published: April 2021

The sizes of commercial transistors are of nanometer order, and there have already been many proposals of spin qubits using conventional complementary metal–oxide–semiconductor transistors. However, most of the previously proposed spin qubits require many wires to control a small number of qubits. This causes a significant “jungle of wires” problem when the qubits are integrated into a chip. Herein, to reduce the complicated wiring, we theoretically consider spin qubits embedded into fin field-effect transistor (FinFET) devices such that the spin qubits share the common gate electrode of the FinFET. The interactions between qubits occur via the Ruderman–Kittel–Kasuya–Yosida interaction via the channel of the FinFET. The possibility of a quantum annealing machine is discussed in addition to the quantum computers of the current proposals.
Research on a modularized long pulse generator based on anti-resonance network and transmission line transformer
Authors: Cheng Xinbing , Chen Rong , Pan Zilong , Yang Jianhua , Geng Jiuyuan
Published: April 2021

A modularized generator with three long pulse modules is designed and constructed in this work. The long pulse module consists of a three-section anti-resonance network and a three-stage transmission line transformer. A single module can output a pulse with an amplitude of 33 kV and a full width at half maximum (FWHM) of 400 ns, when the primary energy storage system provides a voltage of 24 kV. After the three modules are connected in series in experiment, the modularized long pulse generator delivers a high-voltage pulse to the matched load resistor with a maximum voltage of 96 kV and an FWHM of 400 ns. Repetitive experiments at a repetition frequency of 10 Hz are also carried out.
Fast-ion Dα spectroscopy diagnostic at KSTAR
Authors: Yoo J. W. , Kim J. , Lee M. W. , Kang J. , Ko W.–H. , Oh S. G. , Ko J. , Lee J. H. , Nam Y. U. , Jung L. , Park B. H. , Yoon S. W.
Published: April 2021

A fast-ion Dα (FIDA) diagnostics system was installed for core and edge measurements on KSTAR. This system has two tangential FIDA arrays that cover both blue- and redshifted Dα lines (cold: 656.09 nm) in active views along the neutral beam 1 A centerline. The spectral band is 647–662.5 nm, and it covers the Doppler shift of the emission from the maximum energy of the neutral beam (100 keV). A curved filter strip with a motorized stage adequately prevents saturation of the electron multiplying charge-coupled device signal by the cold Dα line from the plasma edge. From comparisons of the measured spectra and FIDASIM modeling code, the FIDA spectra are well matched quantitatively. Moreover, the first measurements show that the FIDA radiance agrees with the neutron rate in the time trace during external heating and perturbation. In addition, responses are observed in the core FIDA radiance during the edge-localized mode cycle.
Subwavelength higher-order topological insulator based on stereo acoustic networks
Authors: Zhang Zhiwang , Cheng Ying , Liu Xiaojun
Published: April 2021

Recently, the concept of a higher-order topological insulator has prompted increasing scientific interest in achieving the lower-dimensional boundary states. Among them, the zero-dimensional topological corner states in 2D/3D stereo acoustic systems are sustained in the second-/third-order topological insulators. However, the wavelength-scale unit size limits the application potential of corner states in acoustics, and the acoustic third-order topological insulator with a subwavelength unit cell is in urgent need to be proposed. Here, we use sub-wavelength acoustic waveguide networks to construct sonic lattices and configure the waveguide size to modulate the coupling strength in both 2D and 3D systems. The topological corner mode of second-/third-order topological insulators appears when the intra-cell coupling strength is weaker than the inter-cell one. Through calculating the eigenfrequencies and simulating the intensity response, the existence of a topological 2D surface, 1D hinge, and 0D corner states is ascertained. We demonstrate that the proposed topological acoustic corner mode may have potential applications in realizing the sound confinement and energy harvesting in both 2D and 3D systems.
High power GaN-based blue superluminescent diodes with low spectral modulation
Authors: Xiong Wei , Hu Lei , Liu Jianping , Jiang Lingrong , Tian Aiqin , Zhang Liqun , Ikeda Masao , Yang Hui
Published: April 2021

We present high-power GaN-based blue superluminescent diodes (SLDs) with bend waveguides. The devices were grown on a c-plane GaN free-standing substrate by metal–organic chemical vapor deposition. Studies on waveguide design were conducted to increase the output power of SLDs. Low spectral modulation had been obtained by optimizing the bend angle of the ridge waveguide. An output power as high as 510 mW had been obtained for SLDs emitting at 441 nm with a full width at half maximum of 4.4 nm.
Bandgap opening in layered gray arsenic alloy
Authors: Chen Cheng , Li Chang , Yu Qiang , Shi Xinyao , Zhang Yushuang , Chen Jie , Liu Kaizhen , He Ying , Zhang Kai
Published: April 2021

As an essential member of group-V layered materials, gray arsenic (g-As) has recently begun to draw researchers’ attention due to fantastic physical properties predicted by theoretical calculation. However, g-As presents semimetal behavior as the thickness exceeds bilayers, which hinders its further device applications, such as in logic electronics. Herein, we report the growth of high quality gray arsenic–phosphorus–tin (g-AsPSn) alloys via a simple one-step chemical vapor transport process. The as-grown g-AsPSn alloy remains the same layered rhombohedral structure as g-As, while the g-AsPSn alloy shows an opened bandgap compared with g-As. Infrared absorption and photoluminescence spectra reveal a narrow optical bandgap of 0.2 eV. A field effect transistor based on few-layer g-AsPSn alloy flakes shows a typical p-type semiconductor behavior and a relatively high mobility of ∼66 cm2 V−1 S−1 under ambient conditions. It can be envisioned that the synthesized two-dimensional layered narrow-gap g-AsPSn alloy presents considerable potential applications in electronics and infrared optoelectronics.
Revealing the mechanism of electric-field-induced phase transition in antiferroelectric NaNbO3 by in situ high-energy x-ray diffraction
Authors: Zhang Mao-Hua , Zhao Changhao , Fulanović Lovro , Rödel Jürgen , Novak Nikola , Schökel Alexander , Koruza Jurij
Published: April 2021

Antiferroelectric materials exhibit electric field-induced phase transitions between antiferroelectric and ferroelectric states, which enable their use in energy storage and other applications. However, the mechanisms of these transitions are insufficiently understood. Here, we considered the electric field-induced phase transition in the lead-free antiferroelectric NaNbO3. Macroscopic measurements of polarization and longitudinal, transverse, and volumetric strain were complemented with simultaneous structural investigations using high-energy x-ray radiation, yielding crystallographic strain and unit cell volume changes. The field-induced behavior can be divided into the structural antiferroelectric–ferroelectric phase transition at about 8 kV/mm and the clearly decoupled polarization switching process at about 12 kV/mm, which is associated with a large increase in polarization and strain. Decoupling of the field-induced phase transition and polarization switching is related to the randomly oriented grains and mechanical stress present at the phase boundary.
Bayesian inference of spatially resolved Zeff profiles from line integrated bremsstrahlung spectra
Authors: Kwak Sehyun , Hergenhahn U. , Höfel U. , Krychowiak M. , Pavone A. , Svensson J. , Ford O. , König R. , Bozhenkov S. , Fuchert G. , Pasch E. , Brunner K. J. , Knauer J. , Kornejew P. , Trimiño Mora Humberto , Pedersen T. S. ,   Wendelstein 7-X Team
Published: April 2021

In nuclear fusion research, the effective ion charge Zeff, which characterizes the overall content of impurities, can be experimentally derived from the plasma electron–ion bremsstrahlung, given the electron density ne and temperature Te. At Wendelstein 7-X, a multichannel near-infrared spectrometer is installed to collect the plasma bremsstrahlung along 27 lines of sight covering more than half the plasma cross section, which provides information on Zeff over the entire plasma radius. To infer spatially resolved Zeff profiles, a Bayesian model is developed in the Minerva framework. Zeff, ne, and Te profiles are modeled as Gaussian processes, whose smoothness is determined by hyperparameters. These profiles are transformed to fields in Cartesian coordinates, given the poloidal magnetic flux surfaces calculated by the variational moments equilibrium code. Given all these physical quantities, the model predicts line-of-sight integrals of near-infrared bremsstrahlung spectra. The model includes the predictive (forward) models of the interferometer, Thomson scattering system, and visible and near-infrared spectrometers. Given the observations of all these diagnostics, the posterior probability distribution of Zeff profiles is calculated and shown as an inference solution. The smoothness (gradient) of the profiles is optimally chosen by Bayesian Occam’s razor. Furthermore, wall reflections can significantly pollute the measurements of the plasma bremsstrahlung, which leads to over-estimation of Zeff values in the edge region. In the first results presented in this work, this problem does not appear, and the posterior samples of Zeff profiles are overall plausible and consistent with Zeff values inferred, given the data from the single-channel visible spectrometer.
Recent enhancements in the performance of the Orion high-resolution x-ray spectrometers
Authors: Hell N. , Beiersdorfer P. , Brown G. V. , Lockard T. E. , Magee E. W. , Shepherd R. , Hoarty D. J. , Brown C. R. D. , Hill M. P. , Hobbs L. M. R. , James S. F. , Lynch C. , Caughey T. A.
Published: April 2021

During the past few years, the Orion high-resolution x-ray spectrometers have been successful tools for measuring x-ray spectra from plasmas generated in the Orion laser facility. Duplicate spectrometers also operate successfully at the Livermore EBIT-I and SuperEBIT electron beam ion traps for measuring x-ray polarization. We have recently implemented very high-quality, optically bonded, spherically bent quartz crystals to remove the structure in the x-ray image that had been observed in earlier measurements. The structure had been caused by focusing defects and limited the accuracy of our measurements. We present before and after images that show a drastic improvement. We, furthermore, have implemented a spherically bent potassium acid phthalate (KAP) crystal on one of our spectrometers. The KAP crystal was prepared in a similar fashion, and we present measurements of the N Ly-β and Ne Lyβ lines taken in first- and second-order reflections at 600 and 1200 eV, respectively. These measurements confirm that KAP crystals can be produced at a quality suitable for extending the spectral coverage to wavelengths longer than those accessible by different quartz crystals, especially those that cover the astrophysically important lines of iron.
New boron nitride monolith phases from high-pressure compression of double-walled boron nitride nanotubes
Authors: Yang Xiaowei , Zhou Si , Huang Shiliang , Zhao Jijun
Published: April 2021

Pressure-induced phase transition of boron nitride nanotubes (BNNTs) provides an effective approach to develop new boron nitride nanostructures with more desirable functions than those of carbon nanotubes, owing to the unique polar B–N bonds. However, the synthetic BNNTs usually comprise double- or multi-walls, whose structural evolution under pressure is complicated and remains largely elusive. Here, we unveil the complete phase transition behavior of hexagonal bundles of double-walled (DW) BNNTs of different chirality and diameters under hydrostatic pressures of up to 60 GPa. A series of new monolith phases are obtained from the compressed DW-BNNT bundles, whose structures can be well retained even after releasing the pressure. The bonding characters; electronic, optical, and mechanical properties; and Raman signature of these monolith phases are elucidated, which provide essential guidance for synthesis of new boron nitride materials with unprecedented properties for technological applications.
Nanopatterned metallic transparent electrodes for the near-infrared spectrum
Authors: Hubarevich Aliaksandr , Marus Mikita , Mukha Yauhen , Smirnov Aliaksandr , Sun Xiao Wei
Published: April 2021

Near-infrared transparent electrodes constitute an essential component of light-emitting and photovoltaic devices widely employed in short- and long-range communication, light detection and ranging, biodiagnostics, security, virtual and augmented reality, night vision, gas sensing, and solar cells. However, the efficiency of all these devices and related applications suffers from significantly reduced transmittance of the indium tin oxide electrode compared to the visible wavelength range. Here, we explore the potential of randomly and uniformly arranged silver, gold, and aluminum nanopore and nanowire films for the near-infrared optoelectronics. We show that these metallic nanopatterned layers, except for randomly arranged nanoporous configurations, exhibit considerably higher performance than the commonly used indium tin oxide. Furthermore, silver layers possess higher transmittance and lower haze than gold and aluminum ones, while the nanowire configuration overperforms the nanoporous one. The obtained results offer a means for deeper analysis of metallic nanopatterned transparent electrodes for many near-infrared optoelectronic applications.
An exact solution in the theory of fluorescence resonance energy transfer with vibrational relaxation
Authors: Mondal Sangita , Mondal Sayantan , Seki Kazuhiko , Bagchi Biman
Published: April 2021

The elegant expression of Förster that predicts the well-known 1/R6 distance (R) dependence of the rate of energy transfer, although widely used, was derived using several approximations. Notable among them is the neglect of the vibrational relaxation in the reactant (donor) and product (acceptor) manifolds. Vibrational relaxation can play an important role when the energy transfer rate is faster than the vibrational relaxation rate. Under such conditions, donor to acceptor energy transfer can occur from the excited vibrational states. This phenomenon is not captured by the usual formulation based on the overlap of donor emission and acceptor absorption spectra. Here, we develop a Green’s function-based generalized formalism and obtain an exact solution for the excited state population relaxation and the rate of energy transfer in the presence of vibrational relaxation. We find that the application of the well-known Förster’s expression might lead to overestimation of R.
Pressure and thermal annealing effects on the photoconversion efficiency of polymer solar cells
Authors: Oyewole D. O. , Oyewole O. K. , Kushnir K. , Shi T. , Oyelade O. V. , Adeniji S. A. , Agyei-Tuffour B. , Evans-Lutterodt K. , Titova L. V. , Soboyejo W. O.
Published: April 2021

This paper presents the results of experimental and theoretical studies of the effects of pressure and thermal annealing on the photo-conversion efficiencies (PCEs) of polymer solar cells with active layers that consist of a mixture of poly(3-hexylthiophene-2,5-diyl) and fullerene derivative (6,6)-phenyl-C61-butyric acid methyl ester. The PCEs of the solar cells increased from ∼2.3% (for the unannealed devices) to ∼3.7% for devices annealed at ∼150 °C. A further increase in thermal annealing temperatures (beyond 150 °C) resulted in lower PCEs. Further improvements in the PCEs (from ∼3.7% to ∼5.4%) were observed with pressure application between 0 and 8 MPa. However, a decrease in PCEs was observed for pressure application beyond 8 MPa. The improved performance associated with thermal annealing is attributed to changes in the active layer microstructure and texture, which also enhance the optical absorption, mobility, and lifetime of the optically excited charge carriers. The beneficial effects of applied pressure are attributed to the decreased interfacial surface contacts that are associated with pressure application. The implications of the results are then discussed for the design and fabrication of organic solar cells with improved PCEs.
A high-efficiency wideband coupler for nanosecond-level pulsed current injection
Authors: Zhou Yi , Xie Yan-zhao , Zhang Dao-zhong
Published: April 2021

Pulsed current injection (PCI), as a conducted vulnerability testing technique under nanosecond-level transient electromagnetic disturbance (TED), has gained great attention recently. Many kinds of TEDs, e.g., high-altitude electromagnetic pulse, very fast transient overvoltage, and electrical fast transients, have very fast rise time as well as pretty slow decay, whose frequency spectrum may cover a very wideband. Therefore, one of the challenges is that the existing inductive couplers cannot interact with the equipment under test (EUT) over the wideband efficiently, and consequently, they are inadequate to inject the proper disturbance at ports of EUT in PCI tests. To address this problem, a high-efficiency wideband PCI coupler is proposed in this paper. The coupling performance is analyzed theoretically based on the distributed-parameter model of an inductive coupler. By using the composited ferrites instead of the simplex Ni–Zn ferrites, the inductive coupling is enhanced. The capacitive coupling is also enhanced to improve the high-frequency performance by exploiting the distributed tubular winding. A PCI coupler with the dimension of 30 × 10 × 10 cm3 is built to be validated experimentally. The 3 dB bandwidth has been improved from 421 kHz–14 MHz to 77 kHz–39 MHz, which indicates that the coupler can be applied efficiently over the frequency range of interest for PCI tests.
Defect characterization by differential capacitance spectroscopy without the Arrhenius plot
Authors: Li Jian V.
Published: April 2021

A new method of Arrhenius transformation and matching is developed in this study based on the rate-temperature duality of the admittance spectroscopy measurement to extract the activation energy Ea and the attempt-to-escape frequency ν0 of a defect in GaAsN from differential capacitance spectroscopy without the Arrhenius plot and without identifying the fdC/df spectra peaks. The method consists of a set of variations that transform the iso-rate scan and/or the isothermal scan to a virtual space—activation energy, attempt-to-escape frequency, temperature, or rate. The transformed scans must be matched prior to extracting Ea and ν0 local to a fixed point in the two-dimensional temperature-rate experimental space.
The squeezes, stretches, and whirls of turbulence
Authors: Johnson Perry L.
Published: April 2021

Fluid turbulence generates a chaotic soup of strongly nonlinear features that are hard to mathematically describe and model. A recent theoretical simplification brings fresh insight.
Alternaria yali-inficiens (chocolate spot of Ya Li pear).
Authors:   USA, USDA-ARS
Published: April 2021

A. yali-inficiens is an asexually reproducing, filamentous fungus known only since its isolation in 2001 from infections on fruit of Ya Li pears (Pyrus bretschneideri), exported from a certain region of China. Although most species of Alternaria are air-disseminated, its ability to spread and establish in other temperate fruit-growing regions is not known. This fungus may pose a threat to native or agricultural plants if introduced. Some countries importing pear fruit from China have established regulatory precautions against it.
Emilia fosbergii (Florida tassel-flower).
Authors: Rojas-Sandoval Julissa , Acevedo-Rodríguez Pedro
Published: April 2021

E. fosbergii is a cosmopolitan annual herb included in the Global Compendium of Weeds (Randall, 2012). It is fast-growing, with the capacity to grow as a weed and colonize disturbed areas, waste ground, gardens, abandoned farmland, coastal forests, forest edges, pastures, roadsides, rocky areas, and riverbanks (Wagner et al., 1999; Vibrans, 2011; Pruski 2014). It produces large amounts of wind-dispersed seeds (>5000 seeds per plant; Mejía et al., 1994) which is a feature facilitating the likelihood of spreading and colonizing new habitats. Currently, E. fosbergii is listed as invasive in Mexico, Central America, West Indies, and on several islands in the Pacific Ocean (see Distribution Table for details).
Icerya samaraia (steatococcus scale).
Authors: Whittaker Angela
Published: April 2021

The scale insect Icerya samaraia (formerly Steatococcus samaraius) occurs in the Australasian, Oriental and Oceanic zoogeographic regions. It has a wide host range which includes mostly woody plant species in 40 genera belonging to 25 families. It is a minor pest of citrus, banana, coconut, guava, papaya, cocoa, pigeon pea and other plants, including forest and ornamental trees. Populations of I. samaraia are apparently being kept under control on the Palau Islands in the western Pacific Ocean by natural enemies, particularly by the introduced coccinellid Rodolia pumila. I. samaraia can be transported on infested plant materials because of its small size and habit of feeding in concealed areas, making it a potential threat as an invasive species.
Fusicladium effusum (pecan scab).
Authors: Bock Clive H.
Published: April 2021

F. effusum is a fungal pathogen that causes pecan scab, which can result in severe economic losses on susceptible cultivars and resulting harm to the pecan industry in areas with high rainfall where pecan is grown. The disease develops on leaves, fruits and shoots and results in loss of photosynthetic area and reduced fruit size and quality. Pecan scab can also lead to reduced fruit set in the following year due to plant stress. Fungicides used to control pecan scab are costly. It is introduced to new areas through movement of infected host material. Despite quarantine restrictions, it is likely that human-mediated transfer has occurred between the native habitats in south-eastern USA and Mexico, and locations where pecan is grown as an exotic in South America, South Africa and New Zealand. F. effusum overwinters as stroma and conidia in lesions on shoots and fruit shucks, and the conidia are dispersed in wind and rain splash. The pathogen is a threat to all pecan-growing regions with a humid, wet environment.
Cleome rutidosperma (fringed spiderflower).
Authors: Rojas-Sandoval Julissa , Acevedo-Rodríguez Pedro
Published: April 2021

C. rutidosperma is a common herb that grows as a weed in disturbed and ruderal habitats, principally in areas with humid and hot environmental conditions. It is often found as a weed of disturbed ground, roadsides, gardens, crops and abandoned lands, and has also been found growing as an epiphyte on trees, stone walls and cliff faces. This species is included in the Global Compendium of Weeds (Randall, 2012) where it is considered to have moderate economic impacts in a wide range of crops, due to its scrambling habit that smothers and stunts young crop plants. C. rutidosperma has been listed as invasive in China, Malaysia, India, Thailand, Vietnam, Australia, and the Domican Republic (Waterhouse and Mitchell, 1998; Kairo et al., 2003; Flora of China Editorial Committee, 2014, USDA-ARS, 2014). This species has had considerable environmental impacts in South East Asia and Australia. C. rutidosperma also has the potential to be moderately problematic in intensive cropping areas, greenhouses and nurseries.