bluuebunny/crossref_metadata_2025 huggingface dataset:
Monolithic integration of 1.3 μm asymmetric lasers grown on silicon and silicon waveguides with tapered coupling
Authors: Jia Yanxing , Wang Jun , Ge Qing , Wang Haijing , Li Jiachen , Xiao Chunyang , Ming Rui , Ma Bojie , Liu Zhuoliang , Zhai Hao , Lin Feng , He Weiyu , Yang Yisu , Liu Kai , Huang Yongqing , Ren Xiaomin
Published: September 2022

We proposed a design scheme to enable the monolithic integration between a silicon waveguide and a 1.3 μm wavelength band III–V quantum dot laser, which is epitaxially grown on silicon with an asymmetric structure. The III–V laser is grown in a deep trench of a silicon-on-insulator wafer by the selective area epitaxy technique, and a GaAs coupling layer is inserted into the lower cladding layer of the laser, which can make the optical field distribution of the laser shift down. Besides, a mode-size converter with a three-segment tapered structure is designed to couple the output laser into the standard single-mode silicon waveguide. For the laser, the composition and the thickness of AlGaAs cladding layers and AlGaAs transition layer are optimized based on the optical waveguide theory. When the upper cladding layer is 0.6 μm Al0.7Ga0.3As, the lower cladding layer is 1.2 μm Al0.25Ga0.75As, and the transition layer is 20 nm Al0.45Ga0.55As, the optical confinement factors of the active region and the coupling layer are 45.34% and 40.69%, respectively. Then the length of the mode-size converter with a three-segment tapered structure is further optimized by the mode-matching method. When the lengths of the three tapered structures of the mode-size converter are 50 μm, 53 μm and 10 μm respectively, a coupling efficiency of 65% can be obtained between the laser and the Si waveguide. This scheme is expected to realize the efficient optical coupling between the silicon integrated light source and the silicon waveguide, which will promote the development of silicon monolithic photonic integration.
Response characteristics of drill-string guided wave in downhole acoustic telemetry
Authors: Zhao Ao-Song , Chen Hao , He Xiao , Wang Xiu-Ming , Cao Xue-Shen
Published: September 2022

Modeling of a drill-string acoustic channel has been an important topic in downhole telemetry for a long time. The propagation of drill-string guided waves in the borehole contains excitation, attenuation, and mode conversion issues that have not been considered by existing modeling methods. In this article, we formulate a hybrid modeling method to investigate the response characteristics of a fundamental-mode drill-string wave in various borehole environments. This hybrid method provides channel functions, including transmitting and receiving deployments, periodicity of the structure, and formation property changes. The essential physics of the drill-string wave propagation is captured with a one-dimensional model. The analytical solutions of the wavefield in multilayered cylindrical structures are introduced into a propagation matrix to express drill-string-wave interactions with the borehole environments. The effectiveness of the proposed method is confirmed through comparison with the finite-difference method. In addition, by designing numerical models, we investigate the conversion effect of the drill-string wave at the tool joint. We demonstrate that the conversion intensity of the drill-string wave is positively correlated not only with the cross-sectional area of the tool joint but also with the wave impedance of the outer formation. Hard formation outside the borehole reduces the energy leakage while intensifying the conversion of drill-string waves to Stoneley waves, and the opposite is true for the drill string in an infinite fluid. The converted Stoneley waves interfere with the drill-string waves, resulting in variations of bandgap distribution, which challenges the reliability of the data transmission.
Effect of temperature on heavy ion-induced single event transient on 16-nm FinFET inverter chains
Authors: Cai Li , Chi Ya-Qing , Ye Bing , Liu Yu-Zhu , He Ze , Wang Hai-Bin , Sun Qian , Sun Rui-Qi , Gao Shuai , Hu Pei-Pei , Yan Xiao-Yu , Li Zong-Zhen , Liu Jie
Published: September 2022

The variations of single event transient (SET) pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor (FinFET) inverter chains with different driven strengths are measured at different temperatures. Three-dimensional (3D) technology computer-aided design simulations are carried out to study the SET pulse width and saturation current varying with temperature. Experimental and simulation results indicate that the increase in temperature will enhance the parasitic bipolar effect of bulk FinFET technology, resulting in the increase of SET pulse width. On the other hand, the increase of inverter driven strength will change the layout topology, which has a complex influence on the SET temperature effects of FinFET inverter chains. The experimental and simulation results show that the device with the strongest driven strength has the least dependence on temperature.
Study of metal–ceramic WC/Cu nano-wear behavior and strengthening mechanism
Authors: Zheng Min , Chen Jie , Zhu Zong-Xiao , Qu Ding-Feng , Chen Wei-Hua , Wu Zhuo , Wang Lin-Jun , Ma Xue-Zhong
Published: September 2022

In view of the inherent poor tribological properties of copper, the reinforcement of copper matrix composites with WC particles presents a promising research area with significant industrial influence. Therefore, in the present study, a molecular dynamics approach is used to simulate the process of repeated friction of diamond grinding balls on WC/Cu composites, and the friction force, friction coefficient, abrasion depth, wear rate, abrasion morphology, von-Mises stress, internal defects, workpiece energy, and performance comparison of different layer thicknesses are systematically investigated in the multiple friction process. It is found that the fluctuation amplitude of friction force, friction coefficient, and abrasion depth are smaller and the fluctuation frequency is larger during the initial friction, whereas near the WC phase, there appears extreme values of the above parameters and the von-Mises stress is highly concentrated while the workpiece energy contonues to increase. In the case of the repeated friction, with the increase of friction times, the friction force, friction coefficient, and abrasion depth fluctuation amplitude increase, the fluctuation frequency decreases, the workpiece energy reaches an extreme value near the WC phase, and a large number of dislocations plug, therefore, the region is strengthened. As the distance between the grinding ball and the WC phase decreases, the more obvious the strengthening effect, the stronger the ability of workpiece to resist the wear will be.
Vortex bound states influenced by the Fermi surface anisotropy
Authors: Fang Delong
Published: September 2022

The spatial distribution of vortex bound states is often anisotropic, which is correlated with the underlying property of materials. In this work, we examine the effects of Fermi surface anisotropy on vortex bound states. The large-scale calculation of vortex bound states is introduced in the presence of fourfold or twofold Fermi surface by solving the Bogoliubov–de Gennes (BdG) equations. Two kinds of quasiparticles' behaviors can be extracted from the local density of states (LDOS) around a vortex. The angle-dependent quasiparticles will move from high energy to low energy when the angle varies from curvature maxima to minima of the Fermi surface, while the angle-independent quasiparticles tend to stay at a relatively higher energy. In addition, the weight of angle-dependent quasiparticles can be enhanced by the increasing anisotropy degree of Fermi surface.
Sensitivity study of the SiGe heterojunction bipolar transistor single event effect based on pulsed laser and technology computer-aided design simulation
Authors: Feng Ya-Hui , Guo Hong-Xia , Pan Xiao-Yu , Zhang Jin-Xin , Zhong Xiang-Li , Zhang Hong , Ju An-An , Liu Ye , Ouyang Xiao-Ping
Published: September 2022

The single event effect of a silicon–germanium heterojunction bipolar transistor (SiGe HBT) was thoroughly investigated. By considering the worst bias condition, the sensitive area of the proposed device was scanned with a pulsed laser. With variation of the collector bias and pulsed laser incident energy, the single event transient of the SiGe HBT was studied. Moreover, the single event transient produced by laser irradiation at a wavelength of 532 nm was more pronounced than at a wavelength of 1064 nm. Finally, the impact of the equivalent linear energy transfer of the 1064 nm pulsed laser on the single event transient was qualitatively examined by performing technology computer-aided design simulations, and a good consistency between the experimental data and the simulated outcomes was attained.
A Meta-analysis of Molecular Spectroscopy Databases, and Prospects of Molecule Detection with Some Future Facilities
Authors: Liu Xin , Du Fujun
Published: September 2022

Molecules reside broadly in the interstellar space and can be detected via spectroscopic observations. To date, more than 271 molecular species have been identified in interstellar medium or circumstellar envelopes. Molecular spectroscopic parameters measured in laboratory make the identification of new species and derivation of physical parameters possible. These spectroscopic parameters are systematically collected into databases, two of the most commonly used being the CDMS and JPL databases. While new spectroscopic parameters are continuously measured/calculated and added to those databases, at any point in time it is the existing spectroscopic data that ultimately limits what molecules can possibly be identified in astronomical data. In this work, we conduct a meta-analysis of the CDMS and JPL databases. We show the statistics of transition frequencies and their uncertainties in these two databases, and discuss the line confusion problem under certain physical environments. We then assess the prospects of detecting molecules in common ISM environments using a few facilities that are expected to be conducting spectroscopic observations in the future. Results show that CSST/HSTDM and SKA1-mid have the potential to detect some complex organic molecules, or even amino acids, with reasonable assumptions about ISM environments.
Investigation of the Oscillations in a Flare-productive Active Region
Authors: Shi Fanpeng , Ning Zongjun , Li Dong
Published: September 2022

We investigate the oscillations in active region (AR) NOAA 12891, which produces a C2.0 three-ribbon flare accompanying a jet on 2021 November 2. Using the data from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory, the 5 minutes decayless kink oscillations of coronal loops were detected and they are independent of the solar flare. Based on the observed oscillations and seismological diagnostics, we estimate that the Alfvén speed and magnetic field in these coronal loops are around 466 km s−1 and 7.6 G, respectively. Additionally, the flare-related jet shows its plasmoids with 1 minute periodicity same as the intensity fluctuation of nearby flare ribbon. The correlation between the intensity fluctuation of jet and that of flare ribbon indicates that their 1 minute oscillations should originate from the same reconnection process.
Evolution of Close Binary System Parameter Distributions
Authors: Zeleke Dugasa Belay , Negu Seblu Humne , Malkov Oleg Yu.
Published: September 2022

In this paper, we investigate the orbital and stellar parameters of low- and intermediate-mass close binary systems. We use models, presented in the catalog of Han et al. and calculate parameters of accretors. We also construct distributions of systems along luminosity, semimajor axis and angular momentum, and make some conclusions on their evolution with time. We compare the results with observational data and it shows a good agreement. The set of theoretical models published quite adequately describes the observational data and, consequently, can be used to determine the evolutionary path of specific close binary systems, their initial parameter values and final stages.
A formalism for sequential estimation of neural membrane time constant and input–output curve towards selective and closed-loop transcranial magnetic stimulation
*
Authors: Alavi S M Mahdi , Vila-Rodriguez Fidel , Mahdi Adam , Goetz Stefan M
Published: September 2022

Objective. To obtain a formalism for real-time concurrent sequential estimation of neural membrane time constant and input–output (IO) curve with transcranial magnetic stimulation (TMS). Approach. First, the neural membrane response and depolarization factor, which leads to motor evoked potentials with TMS are analytically computed and discussed. Then, an integrated model is developed which combines the neural membrane time constant and IO curve. Identifiability of the proposed integrated model is discussed. A condition is derived, which assures estimation of the proposed integrated model. Finally, sequential parameter estimation (SPE) of the neural membrane time constant and IO curve is described through closed-loop optimal sampling and open-loop uniform sampling TMS. Without loss of generality, this paper focuses on a specific case of commercialized TMS pulse shapes. The proposed formalism and SPE method are directly applicable to other pulse shapes. Main results. The results confirm satisfactory estimation of the membrane time constant and IO curve parameters. By defining a stopping rule based on five times consecutive convergence of the estimation parameters with a tolerances of 0.01, the membrane time constant and IO curve parameters are estimated with 82 TMS pulses with absolute relative estimation errors (AREs) of less than 4% with the optimal sampling SPE method. At this point, the uniform sampling SPE method leads to AREs up to 16%. The uniform sampling method does not satisfy the stopping rule due to the large estimation variations. Significance. This paper provides a tool for real-time closed-loop SPE of the neural time constant and IO curve, which can contribute novel insights in TMS studies. SPE of the membrane time constant enables selective stimulation, which can be used for advanced brain research, precision medicine and personalized medicine.
Short pulses of epiretinal prostheses evoke network-mediated responses in retinal ganglion cells by stimulating presynaptic neurons
Authors: Roh Hyeonhee , Otgondemberel Yanjinsuren , Im Maesoon
Published: September 2022

Objective. Microelectronic retinal implant aims to restore functional vision with electric stimulation. Short pulses are generally known to directly activate retinal ganglion cells (RGCs) with a notion of one or two spike(s) per pulse. In the present work, we systematically explore network-mediated responses that arise from various short pulses in both normal and degenerate retinas. Approach. Cell-attached patch clamping was used to record spiking responses of RGCs in wild-type (C57BL/6J) and retinal degeneration (rd10) mice. Alpha RGCs of the mouse retinas were targeted by their large soma sizes and classified by their responses to spot flashes. Then, RGCs were electrically stimulated by various conditions such as duration (100–460 μs), count (1–10), amplitude (100–400 μA), and repeating frequency (10–40 Hz) of short pulses. Also, their responses were compared with each own response to a single 4 ms long pulse which is known to evoke strong indirect responses. Main results. Short pulses evoked strong network-mediated responses not only in both ON and OFF types of RGCs in the healthy retinas but also in RGCs of the severely degenerate retina. However, the spike timing consistency across repeats not decreased significantly in the rd10 RGCs compared to the healthy ON and OFF RGCs. Network-mediated responses of ON RGCs were highly dependent on the current amplitude of stimuli but much less on the pulse count and the repetition frequency. In contrast, responses of OFF RGCs were more influenced by the number of stimuli than the current amplitude. Significance. Our results demonstrate that short pulses also elicit indirect responses by activating presynaptic neurons. In the case of the commercial retinal prostheses using repeating short pulses, there is a possibility that the performance of clinical devices is highly related to the preserved retinal circuits. Therefore, examination of surviving retinal neurons in patients would be necessary to improve the efficacy of retinal prostheses.
Engineering resiliency in UAV swarms–A bibliographic analysis
Authors: Phadke Abhishek , Antonio Medrano F. , Chu Tianxing
Published: September 2022

An Unmanned Aerial Vehicle (UAV) swarm is essentially a network of UAV agents in which coordinating interaction and dependencies are important for successful mission execution. However, the environment that they work in is susceptible to many potential disruptions, such as external weather factors or internal component malfunctions. These disrupt operation and adversely impact overall system performance. To prevent a high rate of mission failure, UAV swarms must exhibit a certain degree of resiliency to disruptions. This study conducts a bibliographical analysis of research on resiliency in UAV swarms over the last decade, and key insights into essential constructs necessary to engineer resilient behavior in UAV swarms are documented. This study also lays the groundwork for future analysis on UAV swarms, with a particular focus on incorporating resiliency to improve performance in the face of disruptions.
Development of an open-source large 3D printer for PLA and ABS
Authors: Barbosa William S. , Gouvea Felipe C. , Wanderley Renan F. F. , Gonçalves Flavia M.
Published: September 2022

The use of 3D printers in additive manufacturing are very common at the last years. The structure, size, movements and type of materials of the printers changes according the use, topology and form of the object that be printed. Although 3D printers are becoming more widespread in the industry and for residential consumers, the size and density of pieces is still a challenge principally at larger pieces. This paper presents all details and specifications of an open-source large 3D printer that uses PLA or ABS, with the aim to verify the impact of these transformations and uses for engineering and industry in general.
Stability analysis of foundation pit against uplift based on circular sliding
Authors: Guo Zhiguang , Liu Yongfu , Zhang Fan
Published: September 2022

The analytical solution of the basal stability coefficient for the excavation is obtained, basing on the principle of mechanical balance and the theory of calculus. The programmatic calculation of the analytical solution is realized with the VB6.0 platform. Furthermore, the factors affecting the basal stability of excavation are analyzed and utilized by the program, including the support position, the construction load, the pile length and cohesion of soil layer at pile bottom. The results show that the construction load has little effect on the stability coefficient. And the closer the bottom steel support is to the bottom of the excavation, the worse the stability of the excavation is. Moreover, as the length of the pile increases (i.e., the radius of the arc increases), the stability factor increases first and then decreases, and its peak occurs when the pile length is 16 m. In addition, the basal stability of excavation will be increased when the pile bottom is cohesive soil.
Numerical investigation on the impingement of spraying jet by an improved smoothed particle hydrodynamics method
Authors: Li Pengfei , Zhang Xiaobing , Wang Liangming
Published: September 2022

An improved smoothed particle hydrodynamics (SPH) method for simulating the high-velocity impingement of compressible jet flow is implemented. This improved SPH method proposes a treatment to restrict the undesired density dissipation in a specific case. In this research, a utility boundary treatment is proposed to simplify the assumption process of the particles approaching the solid boundary, and the principles of the equations employed in the simulation are illustrated in detail. A free surface condition considering the density and kernel function is employed to describe the gas jet accurately. Based on the improved SPH method we discussed, the case of a spraying jet impinging on a solid wall is simulated. The influence of the neglect of the surrounding particles is discussed. It is demonstrated that a closer distance near the free surface of fluid flow will lead to obvious decay of the density and pressure, the presented SPH method provides a reasonable approach to estimate the fluid characters when the amount of calculation is huge and the neglect of surrounding material is necessary.
Toolpath planning for CNC machining of hub surface of blisk
Authors: Zhu Yu , Xiao Shihong , Wang Wenli
Published: September 2022

This paper presented a toolpath planning and generating method for machining a hub surface of a blisk. This method can be used to generate smooth and gradually changing toolpaths and avoid an undercut on hub. In this paper, the hub surface has been defined with a uθ-parametric region. Then character curves, character points and extension curves have been solved in the uθ-parametric region. These curves have been employed to define boundaries of a machining region on the hub surface. The machining region parted by the boundaries has been mapped into a ws-parametric region which was applied to plan toolpaths. The method was employed to mill the hub surface of a blisk, and the results indicated that the profile error of the hub was within ±0.02mm after machining. This method has a significant value of practical applications, and the machining precision can satisfy the designing requirement of a blisk.
Numerical analysis of 3-D inner flow field for ladder-shaped multiple propellant rocket motor
Authors: Zhou Baihang , Wang Hao , Ruan Wenjun
Published: September 2022

In order to study the characteristics of ladder-shaped multiple propellant rocket motor, it was conducted that the numerical simulation of the full 3-D inner flow field for ladder-shaped multiple propellant rocket motor working process using FLUENT calculation software. The secondary development was carried out through UDF interface programming, and the changing rules of the added mass in propellant burning surface and dynamic boundary with the burning rate were set, so that the dynamic process of propellant combustion is accurately simulated. The numerical simulation results demonstrated the spatial distribution information of parameters, such as pressure and flow rate at each moment in the inner flow field, and the pressure-time curves of three monitoring points in front, center and rear of the combustion chamber. Then, several key characteristic moments were selected for specific analysis, and the pressure-time curve of the monitoring point was compared with the experimental data to show that the calculated results were basically accurate. The pressure, flow rate and the pressure difference between the internal and external surfaces of the propellant in the rocket motor inner flow field were analyzed. At present, the dynamic boundary treatment method that the burning rate of the propellant varies regularly with the surface pressure has not been applied in the 3-D calculation model. The research results of this paper can provide reference for the numerical simulation of similar structure of solid rocket motors.
Radon concentration in groundwater of north-eastern Sicily (Italy)
Authors: Romano D. , Magazù S. , Sabatino G. , Di Bella M. , Tripodo A. , Nania G. , Gattuso A. , Italiano F.
Published: September 2022

This paper presents analyses of 222Rn activity
concentration performed on groundwater samples collected from wells
and natural springs in 70 different sites of the crystalline area of
north-eastern Sicily (southern Italy), up to now poorly
studied. Alpha spectroscopy of the short-lived radon progeny was
used to measure the 222Rn activity concentration by means of
the Durridge RAD7 + H2O setup. Radon concentrations were
derived to be in the range of 1.6–57.5 Bq L-1. The higher
values were detected along fluvial valleys and in the crystalline
reliefs, whereas aquifers hosted in the alluvial plains show lower
radon concentrations. The annual effective dose due to intake of
radon by ingestion ranges from 4 to 146.8 μSv y-1. The
average value (56.5 μSv y-1) is below the recommended
limit of 100 μSv y-1 proposed by the World Health
Organization (WHO). In addition, all the measured radon values are
lower than the reference level of 100 Bq L-1 set by the
Italian legislative decree 28/2016 and by the European Directive
2013/51/Euratom. Therefore, all sampling sites are fully compliant
with the legislative requirements in terms of radon
levels. Moreover, results show that the radon levels measured in
groundwater from north-eastern Sicily are similar to those
determined for the adjacent area of southern Calabria, promoting the
assumption of a uniform radon signature in the crystalline domain of
southern Italy. However, further studies are needed to define better
the role of tectonic activity on the content of dissolved radon in
groundwater.
Experimental characterization and Monte Carlo simulation of scintillator detectors in online electron FLASH radiotherapy dosimetry
Authors: Morrocchi Matteo , Pensavalle Jake Harold , Ciarrocchi Esther , Di Martino Fabio , Felici Giuseppe , Galante Federica , Gasparini Alessia , Grasso Luigi , Linsalata Stefania , Massa Maurizio , Moggi Andrea , Pacitti Matteo , Vanreusel Verdi , Verellen Dirk , Bisogni Maria Giuseppina
Published: September 2022

Radiotherapy (RT) is a fundamental tool in cancer
treatment. Recent technological advances improved considerably
radiotherapy techniques, allowing to obtain more precise, effective
and most importantly safer treatments. However, RT is not without
risks. Ionizing radiation also injures healthy cells, and there is a
limit to the amount of radiation an area of the body can safely
receive over the course of a lifetime. A new delivery method, called
FLASH radiotherapy (FLASH-RT) has shown very promising results in
in vivo studies, where a significant increase in healthy
tissue sparing (FLASH effect) was observed. FLASH-RT consists in
delivering the ionizing radiation therapy at dose rates much higher
than the ones used in conventional radiotherapy (CONV-RT). Because
of the novelty of this method, every aspect of FLASH-RT is under
study, such as how the FLASH effect depends on therapy delivery
parameters and what exactly are the underlining biological
mechanisms. Nonetheless, dosimetry presents a challenge to
overcome. The high dose rates cause significant saturation problems
which render standard dosimetric equipment inadequate. Therefore,
the development of online (active) dosimeters is a priority. In the
short term this technology enables more efficient measurements in
the experimental context, since it gives immediate feedback. In the
long term it provides the basis for future studies on dosimetry in
clinical practice.

In this work we show the construction and characterization of online
FLASH dosimeters based on scintillator materials used in
integrating-mode. A GEANT4 based Monte Carlo simulation code is
specifically developed to calculate the medium-equivalence
correction. The simulation is validated with experimental
measurements obtained with a full-fledged FLASH linear accelerator,
which produces electron pulsed beams at very high dose per
pulse. Measurements suggest that the proposed dosimeters have a
linear response in a wide range of dose per pulse values up to
6 Gy/p, while moderate saturation can be observed up to
12.5 Gy/p.
Winding vectors of topological defects: multiband Chern numbers
Authors: Fünfhaus Axel , Kopp Thilo , Lettl Elias
Published: September 2022

Chern numbers can be calculated within a frame of vortex fields related to phase conventions of a wave function. In a band protected by gaps the Chern number is equivalent to the total number of flux carrying vortices. In the presence of topological defects like Dirac cones this method becomes problematic, in particular if they lack a well-defined winding number. We develop a scheme to include topological defects into the vortex field frame. A winding number is determined by the behavior of the phase in reciprocal space when encircling the defect’s contact point. To address the possible lack of a winding number we utilize a more general concept of winding vectors. We demonstrate the usefulness of this ansatz on Dirac cones generated from bands of the Hofstadter model.
Deciphering modes of long-range energy transfer in perovskite crystals using confocal excitation and wide-field fluorescence spectral imaging
Authors: Behera Tejmani , Pathoor Nithin , Mukherjee Rajat , Chowdhury Arindam
Published: September 2022

Excitation energy migration beyond mesoscale is of contemporary interest for both solar photovoltaic and light-emissive devices, especially in context of organometal halide perovskites (OMHPs) which have been shown to have very long (charge carrier) diffusion lengths. While understanding the energy propagation pathways in OMHPs is crucial for further advancement of material design and improvement of opto-electronic features, the simultaneous existence of multiple processes like carrier diffusion, photon recycling, and photon transport makes it often complex to differentiate them. In this study, we unravel the diverse yet dominant excitation energy transfer mode(s) in crystalline MAPbBr3 micron-sized 1D rods and plates by localized (confocal) laser excitation coupled with spectrally-resolved wide-field fluorescence imaging. While rarely used, this technique can efficiently probe excitation migration beyond the diffraction limit and can be realized by simple modification of existing epifluorescence microscopy setups. We find that in rods of length below ∼2 microns, carrier diffusion dominates amongst various energy transfer processes. However, the transient non-radiative defects severely inhibit the extent of carrier migration and also temporarily affect the radiative recombination dynamics of the photo-carriers. For MAPbBr3 plates of several tens of micrometers, we find that the photoluminescence (PL) spectral characteristics remain unaltered at short distances (< ∼3 μm) while at a larger distance, the spectral profile is gradually red-shifted. This implies that carrier diffusion dominates over small distances, while photon recycling, i.e., repeated re-absorption and re-emission of photons, propagates excitation energy transfer over extended length scales with assistance from wave-guided photon transport. Our findings can potentially be used for future studies on the characterization of energy transport mechanisms in semiconductor solids as well as for organic (molecular) self-assembled microstructures.
Wetting of liquid Zinc-aluminum-magnesium alloy on steel substrate during hot-dipping: Understanding the role of the flux
Authors: Xu Minyun , Zheng Zhaoyang , Han Dong , Ma Ruina , Du An , Fan Yongzhe , Zhao Xue , Cao Xiaoming
Published: September 2022

The surface quality of hot-dipping Zn-Al-Mg coatings was significantly influenced by the composition of fluxes. In this study, five different fluxes were chosen and named as F1 (ZnCl2, NH4Cl), F2 (ZnCl2, NaF), F3 (ZnCl2, NH4Cl, KCl), F4 (ZnCl2, NH4Cl, KCl, SnCl2, HCl), and F5 (ZnCl2, NH4Cl, KCl, BiCl3, HCl). Using the sessile drop method, the influence of different fluxes on the wettability between the liquid Zn-Al-Mg alloy and the steel substrate was elucidated. The results showed that: when the flux composition is ZnCl2-NH4Cl-KCl-BiCl3-HCl, a uniform and dense salt film with a protective effect can be formed on the steel substrate, which prevents the oxidation of the steel substrate and removes the harmful reaction products during hot-dipping. By reducing the solid–liquid interface energy, increasing the work of adhesion between the liquid Zn-6Al-3Mg alloy and steel substrate, and shortening the interface reaction time, the strongest wetting effect between the liquid Zn-6Al-3Mg alloy and the steel substrate was achieved. The coating surface quality was the highest after using the F5 flux. Finally, the mechanism of the assistant plating is discussed.
Investigations on the effect of dielectric medium and WEDM parameters on surface characteristics of Al 7068 (ordnance aluminium) alloy
Authors: B Sharmila , G Selvakumar , S Ram Prakash
Published: September 2022

The current experimental work focuses on determining the optimum machining parameter combination for machining AA7068 in wire electrical discharge machining (WEDM). WEDM is a promising advanced machining technology, capable of processing complex-shaped components, machining hard/heat treated materials, and cutting conductive ceramics that are complicated to machine using traditional methods. Taguchi’s L18 orthogonal array is adopted to conduct the experiments by considering dielectric medium, pulse on time, pulse off time, peak current, gap voltage, and wire feed as input factors. The output responses like surface roughness, material removal rate, micro hardness, recast layer, surface morphology of the machined surfaces and wire tool were considered for study. The ANOVA method was used to analyse the impact of individual processing parameters on material removal rate and surface roughness. Microhardness of the cut surface was studied using Vicker’s method. Besides, scanning electron microscopy (SEM) and Energy Dispersive X-Ray analysis are conducted to examine the surface characteristics and elemental composition of the machined working piece at various cutting parameters (EDX). TOPSIS method is chosen to identify the optimal parametric conditions. From the results, the optimum condition achieves surface roughness (3.684 μm) and material removal rate (5.106 mm3 min−1) respectively.
Differential RNA methylation analysis for MeRIP-seq data under general experimental design
Authors: Guo Zhenxing , Shafik Andrew M , Jin Peng , Wu Hao
Published: September 2022

Motivation

RNA epigenetics is an emerging field to study the post-transcriptional gene regulation. The dynamics of RNA epigenetic modification have been reported to associate with many human diseases. Recently developed high-throughput technology named Methylated RNA Immunoprecipitation Sequencing (MeRIP-seq) enables the transcriptome-wide profiling of N6-methyladenosine (m6A) modification and comparison of RNA epigenetic modifications. There are a few computational methods for the comparison of mRNA modifications under different conditions but they all suffer from serious limitations.

Results

In this work, we develop a novel statistical method to detect differentially methylated mRNA regions from MeRIP-seq data. We model the sequence count data by a hierarchical negative binomial model that accounts for various sources of variations and derive parameter estimation and statistical testing procedures for flexible statistical inferences under general experimental designs. Extensive benchmark evaluations in simulation and real data analyses demonstrate that our method is more accurate, robust and flexible compared to existing methods.

Availability and implementation

Our method TRESS is implemented as an R/Bioconductor package and is available at https://bioconductor.org/packages/devel/TRESS.

Supplementary information

Supplementary data are available at Bioinformatics online.
ABEILLE: a novel method for ABerrant Expression Identification empLoying machine LEarning from RNA-sequencing data
Authors: Labory Justine , Le Bideau Gwendal , Pratella David , Yao Jean-Elisée , Ait-El-Mkadem Saadi Samira , Bannwarth Sylvie , El-Hami Loubna , Paquis-Fluckinger Véronique , Bottini Silvia
Published: September 2022

Motivation

Current advances in omics technologies are paving the diagnosis of rare diseases proposing a complementary assay to identify the responsible gene. The use of transcriptomic data to identify aberrant gene expression (AGE) has demonstrated to yield potential pathogenic events. However, popular approaches for AGE identification are limited by the use of statistical tests that imply the choice of arbitrary cut-off for significance assessment and the availability of several replicates not always possible in clinical contexts.

Results

Hence, we developed ABerrant Expression Identification empLoying machine LEarning from sequencing data (ABEILLE) a variational autoencoder (VAE)-based method for the identification of AGEs from the analysis of RNA-seq data without the need for replicates or a control group. ABEILLE combines the use of a VAE, able to model any data without specific assumptions on their distribution, and a decision tree to classify genes as AGE or non-AGE. An anomaly score is associated with each gene in order to stratify AGE by the severity of aberration. We tested ABEILLE on a semi-synthetic and an experimental dataset demonstrating the importance of the flexibility of the VAE configuration to identify potential pathogenic candidates.

Availability and implementation

ABEILLE source code is freely available at: https://github.com/UCA-MSI/ABEILLE.

Supplementary information

Supplementary data are available at Bioinformatics online.
Loss of forebrain BIN1 attenuates hippocampal pathology and neuroinflammation in a tauopathy model
Authors: Ponnusamy Moorthi , Wang Shuai , Yuksel Melike , Hansen Mitchell T , Blazier Danielle M , McMillan Joseph D , Zhang Xiaolin , Dammer Eric B , Collier Lisa , Thinakaran Gopal
Published: September 2022

Bridging integrator 1 (BIN1) is the second most prevalent genetic risk factor identified by genome-wide association studies (GWAS) for late-onset Alzheimer’s disease. BIN1 encodes an adaptor protein that regulates membrane dynamics in the context of endocytosis and neurotransmitter vesicle release. In vitro evidence suggests that BIN1 can directly bind to tau in the cytosol. In addition, BIN1’s function limits extracellular tau seed uptake by endocytosis and subsequent propagation as well as influences tau release through exosomes. However, the in vivo roles of BIN1 in tau pathogenesis and tauopathy-mediated neurodegeneration remain uncharacterized.

We generated conditional knockout mice with a selective loss of Bin1 expression in the forebrain excitatory neurons and oligodendrocytes in P301S human tau transgenic background (line PS19). PS19 mice develop age-dependent tau neuropathology and motor deficits and are commonly used to study Alzheimer’s disease tau pathophysiology. The severity of motor deficits and neuropathology was compared between experimental and control mice that differ with respect to forebrain BIN1 expression. BIN1’s involvement in tau pathology and neuroinflammation was quantified by biochemical methods and immunostaining. Transcriptome changes were profiled by RNA-sequencing analysis to gain molecular insights.

The loss of forebrain BIN1 expression in PS19 mice exacerbated tau pathology in the somatosensory cortex, thalamus, spinal cord and sciatic nerve, accelerated disease progression and caused early death. Intriguingly, the loss of BIN1 also mitigated tau neuropathology in select regions, including the hippocampus, entorhinal/piriform cortex, and amygdala, thus attenuating hippocampal synapse loss, neuronal death, neuroinflammation and brain atrophy. At the molecular level, the loss of forebrain BIN1 elicited complex neuronal and non-neuronal transcriptomic changes, including altered neuroinflammatory gene expression, concomitant with an impaired microglial transition towards the disease-associated microglial phenotype. These results provide crucial new information on in vivo BIN1 function in the context of tau pathogenesis.

We conclude that forebrain neuronal BIN1 expression promotes hippocampal tau pathogenesis and neuroinflammation. Our findings highlight an exciting region specificity in neuronal BIN1 regulation of tau pathogenesis and reveal cell-autonomous and non-cell-autonomous mechanisms involved in BIN1 modulation of tau neuropathology.
Infectious Diseases Society of America Guidelines on the Treatment and Management of Patients With COVID-19 (September 2022)
Authors: Bhimraj Adarsh , Morgan Rebecca L , Shumaker Amy Hirsch , Baden Lindsey R , Cheng Vincent Chi-Chung , Edwards Kathryn M , Gallagher Jason C , Gandhi Rajesh T , Muller William J , Nakamura Mari M , O’Horo John C , Shafer Robert W , Shoham Shmuel , Murad M Hassan , Mustafa Reem A , Sultan Shahnaz , Falck-Ytter Yngve
Published: September 2022

There are many pharmacologic therapies that are being used or considered for treatment of coronavirus disease 2019 (COVID-19), with rapidly changing efficacy and safety evidence from trials. The objective was to develop evidence-based, rapid, living guidelines intended to support patients, clinicians, and other healthcare professionals in their decisions about treatment and management of patients with COVID-19. In March 2020, the Infectious Diseases Society of America (IDSA) formed a multidisciplinary guideline panel of infectious disease clinicians, pharmacists, and methodologists with varied areas of expertise to regularly review the evidence and make recommendations about the treatment and management of persons with COVID-19. The process used a living guideline approach and followed a rapid recommendation development checklist. The panel prioritized questions and outcomes. A systematic review of the peer-reviewed and grey literature was conducted at regular intervals. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the certainty of evidence and make recommendations. Based on the most recent search conducted on 31 May 2022, the IDSA guideline panel has made 32 recommendations for the treatment and management of the following groups/populations: pre- and postexposure prophylaxis, ambulatory with mild-to-moderate disease, and hospitalized with mild-to-moderate, severe but not critical, and critical disease. As these are living guidelines, the most recent recommendations can be found online at: https://idsociety.org/COVID19guidelines. At the inception of its work, the panel has expressed the overarching goal that patients be recruited into ongoing trials. Since then, many trials were conducted that provided much-needed evidence for COVID-19 therapies. There still remain many unanswered questions as the pandemic evolved, which we hope future trials can answer.
Early drop in systolic blood pressure is associated with poor diuretic response and prognosis in patients with acute heart failure
Authors: Dotare Taishi , Maeda Daichi , Matsue Yuya , Sunayama Tsutomu , Kida Keisuke , Kitai Takeshi , Kagiyama Nobuyuki , Yamaguchi Tetsuo , Okumura Takahiro , Mizuno Atsushi , Oishi Shogo , Inuzuka Yasutaka , Akiyama Eiichi , Suzuki Satoshi , Yamamoto Masayoshi , Minamino Tohru
Published: September 2022

Aims

Although an excessive drop in systolic blood pressure (SBP) during acute heart failure (AHF) negatively impacts prognosis, the association between changes in SBP and the diuretic response (DR) is unclear. We aimed to clarify the association between an early drop in SBP and DR/prognosis in patients with AHF.

Methods and results

This was a sub-analysis of the REALITY-AHF study, which registered patients with AHF admitted through emergency departments (EDs). An early SBP drop was defined as the difference between baseline SBP and the lowest value during the first 48 h of hospitalization. DR was defined as the urine output achieved per 40 mg of intravenous furosemide administered. SBP was measured on admission, at 90 min, and 6, 24, and 48 h after admission. Patients were divided into four groups according to their median SBP drop and DR: greater SBP drop/poor DR (n = 322), smaller SBP drop/poor DR (n = 409), greater SBP drop/good DR (n = 419), and smaller SBP drop/good DR (n = 314). The study included 1,464 patients. A greater SBP drop/poor DR was associated with higher baseline SBP and vasodilator use. Multivariable linear regression analysis showed that a greater drop in SBP was associated with poorer DR following adjustment for potential covariates. Cox proportional hazards analysis demonstrated that a greater SBP drop/poor DR was independently associated with 1-year mortality. Both SBP and DR changes were independently associated with prognosis.

Conclusion

An early drop in SBP during the first 48 h of hospitalization was associated with poor DR and 1-year mortality in patients with AHF.

Clinical Trial Registration

URL: http://www.umin.ac.jp/ctr/Unique identifier: UMIN000014105
Cardiac screening prior to return to play after SARS-CoV-2 infection: focus on the child and adolescent athlete: A Clinical Consensus Statement of the Task Force for Childhood Health of the European Association of Preventive Cardiology
Authors: D’Ascenzi Flavio , Castelletti Silvia , Adami Paolo Emilio , Cavarretta Elena , Sanz-de la Garza María , Maestrini Viviana , Biffi Alessandro , Kantor Paul , Pieles Guido , Verhagen Evert , Tiberi Monica , Hanssen Henner , Papadakis Michael , Niebauer Josef , Halle Martin
Published: September 2022

Cardiac sequelae after COVID-19 have been described in athletes, prompting the need to establish a return-to-play (RTP) protocol to guarantee a safe return to sports practice. Sports participation is strongly associated with multiple short- and long-term health benefits in children and adolescents and plays a crucial role in counteracting the psychological and physical effects of the current pandemic. Therefore, RTP protocols should be balanced to promote safe sports practice, particularly after an asymptomatic SARS-CoV-2 infection that represents the common manifestation in children. The present consensus document aims to summarize the current evidence on the cardiac sequelae of COVID-19 in children and young athletes, providing key messages for conducting the RTP protocol in paediatric athletes to promote a safe sports practice during the COVID-19 era.
Saturated fat: villain and bogeyman in the development of cardiovascular disease?
Authors: Valk Reimara , Hammill James , Grip Jonas
Published: September 2022

Aims

Cardiovascular disease (CVD) is the leading global cause of death. For decades, the conventional wisdom has been that the consumption of saturated fat (SFA) undermines cardiovascular health, clogs the arteries, increases risk of CVD, and leads to heart attacks. It is timely to investigate whether this claim holds up to scientific scrutiny. The purpose of this paper is to review and discuss recent scientific evidence on the association between dietary SFA and CVD.

Methods and results

PubMed, Google scholar, and Scopus were searched for articles published between 2010 and 2021 on the association between SFA consumption and CVD risk and outcomes. A review was conducted examining observational studies and prospective epidemiologic cohort studies, randomized controlled trials (RCTs), systematic reviews and meta-analyses of observational studies and prospective epidemiologic cohort studies, and long-term RCTs. Collectively, neither observational studies, prospective epidemiologic cohort studies, RCTs, systematic reviews, and meta-analyses have conclusively established a significant association between SFA in the diet and subsequent cardiovascular risk and coronary artery disease, myocardial infarction, or mortality nor a benefit of reducing dietary SFAs on CVD rick, events, and mortality. Beneficial effects of replacement of SFA by polyunsaturated or monounsaturated fat or carbohydrates remain elusive.

Conclusion

Findings from the studies reviewed in this paper indicate that the consumption of SFA is not significantly associated with CVD risk, events, or mortality. Based on the scientific evidence, there is no scientific ground to demonize SFA as a cause of CVD. SFA naturally occurring in nutrient-dense foods can be safely included in the diet.