bluuebunny/crossref_metadata_2025 huggingface dataset:
Propagation of dislocations in diamond (111) homoepitaxial layer
Authors: Ichikawa Kimiyoshi , Koizumi Satoshi , Teraji Tokuyuki
Published: July 2022

Dislocations in a diamond (111) homoepitaxial layer were investigated in terms of the line directions and types. After a thick homoepitaxial layer was grown on a {111} high-pressure high-temperature (HPHT) substrate using chemical vapor deposition (CVD), the Raman spectra of diamond were taken using a confocal setup to obtain the spatial distribution of the peak positions of the diamond Raman line. Dislocations in the CVD layer and HPHT substrate were detected as local stress variation in the peak position images. The line directions of dislocations were, respectively, [112] for the HPHT substrate and [011] for the CVD layer. Local stress variation was in the [1¯1¯2] direction in both the CVD layer and the HPHT substrate. The Burgers vector deduced from the local stress-variation direction indicated the dislocation structures, respectively, as an edge type for [112] dislocations in the HPHT substrate and as a 60° mixed type for [011] dislocations in the CVD layer. Because both dislocations had the same slip plane, the line direction and dislocation type changed on the same slip plane at the CVD layer/HPHT substrate interface, when dislocation in the HPHT substrate reached the CVD layer.
X-band epi-BAW resonators
Authors: Zhao Wenwen , Asadi Mohammad Javad , Li Lei , Chaudhuri Reet , Nomoto Kazuki , Xing Huili Grace , Hwang James C. M. , Jena Debdeep
Published: July 2022

Using epitaxial aluminum nitride (AlN) developed for ultraviolet photonics and high-speed electronics, we demonstrate suspended AlN thin-film bulk acoustic resonators (FBARs) at 9.2 GHz in the X-band (8–12 GHz) of the microwave spectrum. The resonators show a Qmax≈614 and a figure of merit f⋅Q≈5.6 THz. The material stack of these epi-AlN FBARs allows monolithic integration with AlN/GaN/AlN quantum well high-electron-mobility-transistors to a unique RF front end and also enable integration with epitaxial nitride superconductors for microwave filters for quantum computing.
Electrochemical-tunable and mesostructure-dependent abrupt-to-progressive conversion in fibroin-based transient memristor
Authors: Zhao Xinhui , Chang Ke , Liu Binbin , Jiang Kang'an , Hu Chenhua , Wang Ying , Wang Hui
Published: July 2022

The unique degradability and excellent biocompatibility make silk fibroin an attractive material for flexible transient memristors. Materials functionalization from the mesoscopic reconstruction view is a promising route to expand functions and create new types of electronic devices. Here, the transformation of the abrupt-to-progressive switching behavior in fibroin-based memristors is achieved via annealing to adjust the mesoscopic structure. Through electrical test and scanning electron microscope analysis, we study the electrochemical dynamics of metal nanoparticles in switching medium with different mesoscopic structures and directly reveal the microscopic origin of the abrupt-to-progressive transformation in fibroin-based transient memristors. The device exhibits abrupt resistive switching behaviors when the mobility and redox rate are high and displays progressive resistive switching behaviors under the low mobility and low redox rate condition. These findings reveal the microscopic origins of abrupt-to-progressive conversion and provide general guidance for designing high-performance memory devices and artificial synapses.
Identifying important environmental variables in the niche partitioning of two keystone ecosystem engineers (Bettongia gaimardi and Potorous tridactylus) in Tasmania
Authors: Standaloft Isaac , Kirkpatrick Jamie B.
Published: July 2022

Context The eastern bettong (Bettongia gaimardi) and the long-nosed potoroo (Potorous tridactylus) are mycophagous marsupials regarded as both keystone species and ecosystem engineers. Despite Tasmania being a refuge for these declining species, their niche partitioning is poorly understood. Aims Our aim was to identify factors that distinguish the distributions of B. gaimardi and P. tridactylus, and to develop a better explanation of their individual niches. Methods The Department of Primary Industries, Parks, Water and Environment conducted mammal surveys between 1975 and 2019. We used GIS to analyse these data, and geospatial information to identify relationships between B. gaimardi and P. tridactylus presence/absence and environmental variables. We then developed a model describing the distributions of these species in Tasmania. Key results Temperature seasonality (s.d. × 100), precipitation of wettest month (mm), precipitation of the driest month (mm), precipitation seasonality (coefficient of variation), the presence of vegetation dominated by Eucalyptus amygdalina and the presence of lowland grassy woodland/forest were the components in the best model for B. gaimardi. Our model broadly predicts that the distribution of B. gaimardi is restricted to the more fertile eastern half of Tasmania. P. tridactylus was associated with very few variables, with the presence of E. amygdalina–Eucalyptus obliqua damp forest being the only component in a very weak model. Transects with P. tridactylus and not B. gaimardi were more associated with rainforest and wet forest communities and areas of higher annual and wettest-month precipitation than were those with B. gaimardi and not P. tridactylus. Conclusions The importance of infertile sites to B. gaimardi may have been overstated in the literature, with moderate to high fertility being more characteristic of its range. B. gaimardi is adapted to persist in environments of low truffle (food) density, typical of the eastern half of Tasmania, through its ability to adopt a larger home range than for P. tridactylus, which requires dense ground vegetation. Implications Sites of high fertility in fragmented landscapes should be considered to be potential habitat for B. gaimardi. This challenges previous assumptions that infertile sites are the primary habitat of the species, with fertile sites offering poorer-quality habitat.
Triplet-pair spin signatures from macroscopically aligned heteroacenes in an oriented single crystal
Authors: Rugg Brandon K. , Smyser Kori E. , Fluegel Brian , Chang Christopher H. , Thorley Karl J. , Parkin Sean , Anthony John E. , Eaves Joel D. , Johnson Justin C.
Published: July 2022

The photo-driven process of singlet fission generates coupled triplet pairs (TT) with fundamentally intriguing and potentially useful properties. The quintet5TT0sublevel is particularly interesting for quantum information because it is highly entangled, is addressable with microwave pulses, and could be detected using optical techniques. Previous theoretical work on a model Hamiltonian and nonadiabatic transition theory, called theJDEmodel, has determined that this sublevel can be selectively populated if certain conditions are met. Among the most challenging, the molecules within the dimer undergoing singlet fission must have their principal magnetic axes parallel to one another and to an applied Zeeman field. Here, we present time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy of a single crystal sample of a tetracenethiophene compound featuring arrays of dimers aligned in this manner, which were mounted so that the orientation of the field relative to the molecular axes could be controlled. The observed spin sublevel populations in the paired TT and unpaired (T+T) triplets are consistent with predictions from theJDEmodel, including preferential5TT0formation atz‖ B0, with one caveat—two5TT spin sublevels have little to no population. This may be due to crossings between the5TT and3TT manifolds in the field range investigated by TR-EPR, consistent with the intertriplet exchange energy determined by monitoring photoluminescence at varying magnetic fields.
Fast, strong, and reversible adhesives with dynamic covalent bonds for potential use in wound dressing
Authors: Chen Mingtao , Wu Yue , Chen Baohong , Tucker Alexander M. , Jagota Anand , Yang Shu
Published: July 2022

Adhesives typically fall into two categories: those that have high but irreversible adhesion strength due to the formation of covalent bonds at the interface and are slow to deploy, and others that are fast to deploy and the adhesion is reversible but weak in strength due to formation of noncovalent bonds. Synergizing the advantages from both categories remains challenging but pivotal for the development of the next generation of wound dressing adhesives. Here, we report a fast and reversible adhesive consisting of dynamic boronic ester covalent bonds, formed between poly(vinyl alcohol) (PVA) and boric acid (BA) for potential use as a wound dressing adhesive. Mechanical testing shows that the adhesive film has strength in shear of 61 N/cm
2
and transcutaneous adhesive strength of 511 N/cm
2
, generated within 2 min of application. Yet the film can be effortlessly debonded when exposed to excess water. The mechanical properties of PVA/BA adhesives are tunable by varying the cross-linking density. Within seconds of activation by water, the surface boronic ester bonds in the PVA/BA film undergo fast debonding and instant softening, leading to conformal contact with the adherends and reformation of the boronic ester bonds at the interface. Meanwhile, the bulk film remains dehydrated to offer efficient load transmission, which is important to achieve strong adhesion without delamination at the interface. Whether the substrate surface is smooth (e.g., glass) or rough (e.g., hairy mouse skin), PVA/BA adhesives demonstrate superior adhesion compared to the most widely used topical skin adhesive in clinical medicine, Dermabond.
Regulation of the COPII secretory machinery via focal adhesions and extracellular matrix signaling
Authors: Jung Juan , Khan Muzamil Majid , Landry Jonathan , Halavatyi Aliaksandr , Machado Pedro , Reiss Miriam , Pepperkok Rainer
Published: July 2022

Proteins that enter the secretory pathway are transported from their place of synthesis in the endoplasmic reticulum to the Golgi complex by COPII-coated carriers. The networks of proteins that regulate these components in response to extracellular cues have remained largely elusive. Using high-throughput microscopy, we comprehensively screened 378 cytoskeleton-associated and related proteins for their functional interaction with the coat protein complex II (COPII) components SEC23A and SEC23B. Among these, we identified a group of proteins associated with focal adhesions (FERMT2, MACF1, MAPK8IP2, NGEF, PIK3CA, and ROCK1) that led to the downregulation of SEC23A when depleted by siRNA. Changes in focal adhesions induced by plating cells on ECM also led to the downregulation of SEC23A and decreases in VSVG transport from ER to Golgi. Both the expression of SEC23A and the transport defect could be rescued by treatment with a focal adhesion kinase inhibitor. Altogether, our results identify a network of cytoskeleton-associated proteins connecting focal adhesions and ECM-related signaling with the gene expression of the COPII secretory machinery and trafficking.
Improved Evaluation of BBR and Collisional Frequency Shifts of NIM-Sr2 with 7.2 × 10−18 Total Uncertainty
Authors: Lu Bing-Kun , Sun Zhen , Yang Tao , Lin Yi-Ge , Wang Qiang , Li Ye , Meng Fei , Lin Bai-Ke , Li Tian-Chu , Fang Zhan-Jun
Published: July 2022

NIM-Sr2 optical lattice clock has been developed on the Changping campus of National Institute of Metrology (NIM). Considering the limitations in NIM-Sr1, several improved parts have been designed including a differential pumping stage in the vacuum system, a permanent magnet Zeeman slower, water-cooled anti-Helmholtz coils, an extended viewport for Zeeman slower, etc. A clock laser with a short-time stability better than 3 × 10−16 is realized based on a self-designed 30-cm-long ultra-low expansion cavity. The systematic frequency shift has been evaluated to an uncertainty of 7.2 × 10−18, with the uncertainty of BBR shift and the collisional frequency shift being an order of magnitude lower than the last evaluation of NIM-Sr1.
Spin-orbit torque assisted magnetization reversal of 100 nm-long vertical pillar
Authors: Honda Syuta , Sonobe Yoshiaki
Published: July 2022

Long vertical pillars, with a width of the order of nanometers and with perpendicular shape anisotropy (PSA), have high thermal stability. The advantage of using longer pillars is that they can increase the memory areal density while maintaining robust thermal stability. The current-induced magnetization reversal of long pillars is a significant challenge in spintronic applications such as high-density magnetic memories. However, the magnetization of pillars that are more than 100 nm long has never been reversed by spin-orbit torque (SOT) or spin injection from another ferromagnet (FM). Against this background, we propose a novel magnetization reversal method for pillars based on both SOT and spin transfer torque without using a FM for spin injection. Furthermore, this SOT-assisted method significantly reduces the reversal time, as was demonstrated by micromagnetic simulation. Using a spin-polarized current and SOT, the magnetization was reversed in pillars with length ⩾100 nm. The magnetization of pillars with PSA and those with both high perpendicular magnetic anisotropy and PSA was successfully reversed. The findings of this study are physically novel and significant for practical applications. Consequently, the proposed new writing scheme paves the way for next-generation spintronic devices.
The potential of AFM in studying the role of the nanoscale amphipathic nature of (lipo)-peptides interacting with lipid bilayers
Authors: Mescola Andrea , Ragazzini Gregorio , Facci Paolo , Alessandrini Andrea
Published: July 2022

Antimicrobial peptides (AMPs) and lipopeptides (LPs) represent very promising molecules to fight resistant bacterial infections due to their broad-spectrum of activity, their first target, i.e. the bacterial membrane, and the rapid bactericidal action. For both types of molecules, the action mechanism starts from the membrane of the pathogen agents, producing a disorganization of their phase structure or the formation of pores of different size altering their permeability. This mechanism of action is based on physical interactions more than on a lock-and-key recognition event and it is difficult for the pathogens to rapidly develop an effective resistance. Very small differences in the sequence of both AMPs and LPs might lead to very different effects on the target membrane. Therefore, a correct understanding of their mechanism of action is required with the aim of developing new synthetic peptides, analogues of the natural ones, with specific and more powerful bactericidal activity. Atomic force microscopy (AFM), with its high resolution and the associated force spectroscopy resource, provides a valuable technique to investigate the reorganization of lipid bilayers exposed to antimicrobial or lipopeptides. Here, we present AFM results obtained by ours and other groups on the action of AMPs and LPs on supported lipid bilayers (SLBs) of different composition. We also consider data obtained by fluorescence microscopy to compare the AFM data with another technique which can be used on different lipid bilayer model systems such as SLBs and giant unilamellar vesicles. The outcomes here presented highlight the powerful of AFM-based techniques in detecting nanoscale peptide-membrane interactions and strengthen their use as an exceptional complementary tool to in vivo investigations. Indeed, the combination of these approaches can help decipher the mechanisms of action of different antimicrobials and lipopeptides at both the micro and nanoscale levels, and to design new and more efficient antimicrobial compounds.
Fast VMAT planning for prostate radiotherapy: dosimetric validation of a deep learning-based initial segment generation method
Authors: Ni Yimin , Chen Shufei , Hibbard Lyndon , Voet Peter
Published: July 2022

Objective. To develop and evaluate a deep learning based fast volumetric modulated arc therapy (VMAT) plan generation method for prostate radiotherapy. Approach. A customized 3D U-Net was trained and validated to predict initial segments at 90 evenly distributed control points of an arc, linked to our research treatment planning system (TPS) for segment shape optimization (SSO) and segment weight optimization (SWO). For 27 test patients, the VMAT plans generated based on the deep learning prediction (VMATDL) were compared with VMAT plans generated with a previously validated automated treatment planning method (VMATref). For all test cases, the deep learning prediction accuracy, plan dosimetric quality, and the planning efficiency were quantified and analyzed. Main results. For all 27 test cases, the resulting plans were clinically acceptable. The V
95% for the PTV2 was greater than 99%, and the V
107% was below 0.2%. Statistically significant difference in target coverage was not observed between the VMATref and VMATDL plans (P = 0.3243 > 0.05). The dose sparing effect to the OARs between the two groups of plans was similar. Small differences were only observed for the Dmean of rectum and anus. Compared to the VMATref, the VMATDL reduced 29.3% of the optimization time on average. Significance. A fully automated VMAT plan generation method may result in significant improvement in prostate treatment planning efficiency. Due to the clinically acceptable dosimetric quality and high efficiency, it could potentially be used for clinical planning application and real-time adaptive therapy application after further validation.
3D printing methods for radiological anthropomorphic phantoms
Authors: Okkalidis Nikiforos
Published: July 2022

Three dimensional (3D) printing technology has been widely evaluated for the fabrication of various anthropomorphic phantoms during the last couple of decades. The demand for such high quality phantoms is constantly rising and gaining an ever-increasing interest. Although, in a short time 3D printing technology provided phantoms with more realistic features when compared to the previous conventional methods, there are still several aspects to be explored. One of these aspects is the further development of the current 3D printing methods and software devoted to radiological applications. The current 3D printing software and methods usually employ 3D models, while the direct association of medical images with the 3D printing process is needed in order to provide results of higher accuracy and closer to the actual tissues’ texture. Another aspect of high importance is the development of suitable printing materials. Ideally, those materials should be able to emulate the entire range of soft and bone tissues, while still matching the human’s anatomy. Five types of 3D printing methods have been mainly investigated so far: (a) solidification of photo-curing materials; (b) deposition of melted plastic materials; (c) printing paper-based phantoms with radiopaque ink; (d) melting or binding plastic powder; and (e) bio-printing. From the first and second category, polymer jetting technology and fused filament fabrication (FFF), also known as fused deposition modelling (FDM), are the most promising technologies for the fulfilment of the requirements of realistic and radiologically equivalent anthropomorphic phantoms. Another interesting approach is the fabrication of radiopaque paper-based phantoms using inkjet printers. Although, this may provide phantoms of high accuracy, the utilized materials during the fabrication process are restricted to inks doped with various contrast materials. A similar condition applies to the polymer jetting technology, which despite being quite fast and very accurate, the utilized materials are restricted to those capable of polymerization. The situation is better for FFF/FDM 3D printers, since various compositions of plastic filaments with external substances can be produced conveniently. Although, the speed and accuracy of this 3D printing method are lower compared to the others, the relatively low-cost, constantly improving resolution, sufficient printing volume and plethora of materials are quite promising for the creation of human size heterogeneous phantoms and their adaptation to the treatment procedures of patients in the current health systems.
Monitoring residual kidney function in haemodialysis patients using timed urine collections: validation of the use of estimated blood results to calculate GFR
Authors: Lindley Elizabeth , Keane David , Belcher John , Fernandes Da Silva Jeffcoat Nancy , Davies Simon
Published: July 2022

Objective. With growing recognition of the benefits of preserving residual kidney function (RKF) and use of incremental treatment regimes, the incentive to measure residual clearance in haemodialysis patients is increasing. Interdialytic urine collections used to monitor RKF in research studies are considered impractical in routine care, partly due to the requirement for blood samples before and after the collection. Plasma solute levels can be estimated if patients are in ‘steady state’, where urea and creatinine concentrations increase at a constant rate between dialysis sessions and are reduced by a constant ratio at each session. Validation of the steady state assumption would allow development of simplified protocols for urine collections in HD patients. Approach. Equations were derived for estimating plasma urea and creatinine at the start or end of the interdialytic interval for patients in steady state. Data collected during the BISTRO study was used to assess the agreement between measured and estimated plasma levels and the effect of using estimated levels on the calculated glomerular filtration rate (GFR). Main results. The mean difference between GFR calculated with estimated plasma levels for the HD session after the collection and a full set of measured levels was 2.0% (95% limits of agreement −10.7% to +14.7%, N = 316). Where plasma levels for the session before the collection were estimated, the mean difference was 1.2% (limits of agreement −10.3% to +7.9%, N = 275). Significance. Using estimated levels for one session led to a clinically significant difference in the calculated GFR for less than 3% of the collections studied. This indicates that the steady state assumption can be used to estimate solute levels when determining GFR from timed urine collections. A pragmatic approach to monitoring RKF in HD would be for patients to collect for approximately 24 h before routine bloods are taken.
An off-center fed patch antenna with overlapping sub-patch for simultaneous crack and temperature sensing
Authors: Li Xianzhi , Xue Songtao , Xie Liyu , Wan Guochun , Wan Chunfeng
Published: July 2022

This paper presents an off-center fed patch antenna for simultaneous crack and temperature sensing. The antenna sensor consists of an off-center fed underlying patch and an overlapping sub-patch. The bottom copper sheet of the sub-patch is tightly attached to the underlying radiation patch allowing the electric current to flow through the integrated patch. The off-center feeding can activate the resonant modes in both transverse and longitudinal directions. The transverse resonant frequencies of the combined patch are utilized for temperature sensing. Therefore, the crack width sensed by the longitudinal frequency shift can be adjusted, eliminating the temperature effect. In addition, this unstressed structure of the combined patch can avoid the issues of incomplete strain transfer ratio and the insufficient bonding strength of a monolithic antenna. The authors developed theoretical relationships between the antenna resonant frequencies, the temperature, and the crack width. They also developed simulations of the off-center fed patch antenna sensor as well as a series of experimental tests to demonstrate the feasibility of the proposed sensor for simultaneous crack and temperature sensing.
Bolt looseness monitoring based on damping measurement by using a quantitative electro-mechanical impedance method
Authors: Qiu Hao , Li Faxin
Published: July 2022

In-situ bolt looseness monitoring is very important for the stability and safety of engineering structures. The electro-mechanical impedance (EMI) method, which had been intensively studied in structure health monitoring, has offered a feasible solution. However, in traditional EMI method, the lack of modal pre-selection leads to dense resonant peaks which brings difficulty to signal analysis. The commonly used statistical damage indices typically do not have physics meaning and may fail to distinguish the defects from the environmental changes. In this work, a quantitative EMI (Q-EMI) method was proposed to measure the damping of structures for bolt looseness monitoring. The in-plane excitation method based on distributed thickness-shear-mode piezoelectric transducers was used for selective excitation of vibration modes. The modal-related sensitivity variation was theoretically analyzed and then validated by experiments. Three different specimens were tested and the results showed that during bolt loosening, the modal damping increased by 100%–300%, while the resonance frequency of the structure only decreased by several percent. Moreover, it was found that the loosened bolt may be located using the variation of modal-related sensitivity. Due to its good performance and easy mounting, the proposed Q-EMI method is very promising for bolt looseness monitoring and is expected to be widely used in near future.
Nonvolatile memory cell using a superconducting-ferromagnetic π Josephson junction
Authors: Zeng Junwen , Chen Lei , Zhong Xianghai , Wang Yue , Pan Yinping , Zhang Denghui , Yu Shujie , Wu Ling , Zhang Lu , Peng Wei , Wang Zhen
Published: July 2022

Storage of a single magnetic flux quantum in a superconducting loop containing a Josephson junction represents a promising unit cell configuration for construction of a cryogenic memory of superconducting digital circuits. However, application of a DC bias current is required for operation of such a memory cell to maintain trapping of the flux quantum in the storage loop. In this work, we present a superconducting memory cell that uses a superconducting-magnetic π junction. The cell characteristics show flux quantum hysteresis centering at the zero-bias current. We develop a fabrication process that combines superconductor–ferromagnet–superconductor (SFS) junctions with superconductor–normal metal–superconductor (SNS) junctions. The critical current density of the SFS junctions shows a 0–π oscillation as a function of the ferromagnetic layer thickness. The formation of the π junction is confirmed further by the flux modulation curves of a superconducting quantum interference device made from SNS junctions with an additional SFS junction.
Experimental study of the influence of annular nozzle on acoustic characteristics of detonation sound wave generated by pulse detonation engine
Authors: Kang Yang , Li Ning , Huang Xiao-Long , Weng Chun-Sheng
Published: July 2022

Acoustic characteristics of the detonation sound wave generated by a pulse detonation engine with an annular nozzle, including peak sound pressure, directivity, and A duration, are experimentally investigated while utilizing gasoline as fuel and oxygen-enriched air as oxidizer. Three annular nozzle geometries are evaluated by varying the ratio of inner cone diameter to detonation tube exit diameter from 0.36 to 0.68. The experimental results show that the annular nozzles have a significant effect on the acoustic characteristics of the detonation sound wave. The annular nozzles can amplify the peak sound pressure of the detonation sound wave at 90° while reducing it at 0° and 30°. The directivity angle of the detonation sound wave is changed by annular nozzles from 30° to 90°. The A duration of the detonation sound wave at 90° is also increased by the annular nozzles. These changes indicate that the annular nozzles have an important influence on the acoustic energy distribution of the detonation sound wave, which amplify the acoustic energy in a direction perpendicular to the tube axis and weaken it along the direction of the tube axis.
Resonant perfect absorption of molybdenum disulfide beyond the bandgap
Authors: Yu Hao , Xie Ying , Wei Jiahui , Zhang Peiqing , Cui Zhiying , Yu Haohai
Published: July 2022

Light absorption and radiation are fundamental processes in optical science and engineering. Materials with perfect absorption properties play an important role in numerous optical applications. Following the meteoric rise of MoS2 material, global opportunities and challenges coexist due to its extremely weak light–matter interaction capability beyond its energy band. In this work, we designed a kind of sandwich resonance structure and investigated MoS2 as a perfect absorber in the infrared spectrum that should be transparent according to the optical band theory. The infrared absorption properties of W or Au/MoS2/Au models at 800 nm–2400 nm were systematic simulated. By optimizing the structural parameters, the resonant wavelength of perfect absorption can be modulated from 830 nm to 1700 nm with angle insensitivity and polar independence. Moreover, we discovered that the bandwidth of absorption exceeding 50% of the W-top model reaches 500 nm, while that of the Au-top model is less than 100 nm, indicating that the top metal material has a great influence on the resonance absorption spectrum. Our work provides a practical route for enhancing and manipulating the light–matter interactions of low-dimensional materials beyond their own band gaps, which will be critical in the future design and implementation of optoelectronic devices and systems.
Investigating the characteristic delay time in the leader-follower behavior in children single-file movement
Authors: Xue Shu-Qi , Shiwakoti Nirajan , Shi Xiao-Meng , Xiao Yao
Published: July 2022

The single-file movement experiment offered a convenient way to investigate the one-dimensional leader–follower behavior of pedestrians. This study investigated the time delays of children pedestrians in the leader–follower behavior by introducing a time-dependent delayed speed correlation. A total of 118 German students from the fifth grade (aged 11–12 years old) and the 11th grade (aged 17–18 years old) participated the single-file experiment. The characteristic delay time for each pedestrian was identified by optimising the time-dependent delayed speed correlation. The influences of the curvature of the experimental scenario, density, age, and gender on the delay time were statistically examined. The results suggested that to a large extent, the revealed characteristic delay time was a density-dependent variable, and none of the curvatures, the age and gender of the individual, and the age and gender of the leader had a significant influence on it. The findings from this study are variable resources to understand the leader–follower behavior among children pedestrians and to build related simulation models.
Real-time programmable coding metasurface antenna for multibeam switching and scanning
Authors: Yu Jia-Yu , Zheng Qiu-Rong , Zhang Bin , He Jie , Hu Xiang-Ming , Liu Jie
Published: July 2022

Novel electromagnetic wave modulation by programmable dynamic metasurface promotes the device design freedom, while multibeam antennas have sparked tremendous interest in wireless communications. A programmable coding antenna based on active metasurface elements (AMSEs) is proposed in this study, allowing scanning and state switching of multiple beams in real time. To obtain the planar array phase distribution in quick response, the aperture field superposition and discretization procedures are investigated. Without the need for a massive algorithm or elaborate design, this electronically controlled antenna with integrated radiation and phase-shift functions can flexibly manipulate the scattering state of multiple beams under field-programmable gate array (FPGA) control. Simulation and experimental results show that the multiple directional beams dynamically generated in the metasurface upper half space have good radiation performance, with the main lobe directions closely matching the predesigned angles. This metasurface antenna has great potential for future applications in multitarget radar, satellite navigation, and reconfigurable intelligent metasurfaces.
Polarization Raman spectra of graphene nanoribbons
Authors: Xu Wangwei , Sun Shijie , Yang Muzi , Hao Zhenliang , Gao Lei , Lu Jianchen , Zhu Jiasen , Chen Jian , Cai Jinming
Published: July 2022

The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons (GNRs), which bears great potential in electronic applications. Here, we synthesize armchair graphene nanoribbons (AGNRs) and chevron-type graphene nanoribbons (CGNRs) array on a vicinal Au(11 11 12) surface using 10,10′-dibromo-9,9′-bianthracene (DBBA) and 6,12-dibromochrysene (DBCh) as precursors, respectively. This process creates spatially well-aligned GNRs, as characterized by scanning tunneling microscopy. AGNRs show strong Raman linear polarizability for application in optical modulation devices. Different from the distinct polarization of AGNRs, only weak polarization exists in CGNRs polarized Raman spectrum, which suggests that the presence of the zigzag boundary in the nanoribbon attenuates the polarization rate as an important factor affecting the polarization. We analyze the Raman activation mode of CGNRs using the peak polarization to expand the application of the polarization Raman spectroscopy in nanoarray analysis.
The fracture and merging of W nanofibers under low-energy He ion irradiations at an elevated temperature
Authors: Zhang Yang , Fan Hongyu , Liu Dongping , Li Xiaoping , Cui Yunqiu , Niu Chunjie , Liu Weifeng , Ni Weiyuan , Wang Wenchun
Published: July 2022

The microstructural evolution of tungsten (W) nanofibers has been observed during the W fuzz growth due to low-energy He+ irradiations at an elevated temperature. In this study, we find that the frequent fracture and merging of W nanofibers occur during the W fuzz growth. Our annealing experiments also show the fracture and instability of W nanofibers at an elevated temperature. Detailed analysis reveals the tensile-stress driven thermodynamic instability of W nanofibers containing plenty of helium (He) bubbles at an elevated temperature. The mergence of W nanofibers coming into contact with each other is due to the deposition of W adatoms diffusing over W nanofibers onto the mergence locations, which decreases the surface free energy of W nanofibers. The fracture of W nanofibers is attributed to the tensile stress induced cracking of W nanofibers containing He bubbles, and the subsequent W adatom surface diffusion over W nanofibers.
Evolution of charged particles in jet combustion chamber
Authors: Li Wang
Published: July 2022

The combustion process in the combustion chamber of the engine will change the electrostatic field characteristics of the jet aircraft, thereby affecting the accuracy of the electrostatic field information obtained by the electrostatic detector. Based on the quantitative analysis of the evolution of charged particles in the combustion chamber, this study further analyses the effect of different surface materials in the combustion chamber on the charging process of combustion products. The combustion chamber is divided into burning zone, intermediate zone and dilution zone, and the evolution model of charged particles in the combustion chamber is constructed under the time constraint. Finally, the variation curve of the charged particle concentration when the surface materials in the combustion chamber are metal materials and non-metal materials are calculated by simulation, and the influence of the conductivity of the surface materials in the combustion chamber on the combustion charging process is analyzed. This study provides the analytical basis for the application of electrostatic detection technology in jet aircraft.
Improvement of parameters of micro-pixel avalanche photodiodes
Authors: Sadigov A.Z. , Ahmadov F.I. , Sadygov Z.Y. , Ahmadov G.S. , Berikov D. , Holik M. , Mammadli A. , Akbarov R.A. , Nuruyev S.M. , Ajdarli K. , Garibli A. , Doganci E. , Mora Y. , Yilmaz E.
Published: July 2022

The paper is concerned with the parameter study of a new
generation of micro-pixel avalanche photodiodes (MAPD) with deeply
buried pixel structure, also named silicon photomultipliers (SiPM)
or multi-pixel photon counter (MPPC). The new MAPD of type MAPD-3NM
was manufactured in the frame of collaboration with Zecotek
Company. Measurements were carried out and discussed in terms of the
important parameters such as the current-voltage and
capacitance-voltage characteristic, gain, the temperature
coefficient of breakdown voltage, breakdown voltage, and gamma-ray
detection performance using an LFS scintillator. The obtained
results showed that the newly developed MAPD-3NM photodiode
outperformed the previous generation in most parameters and can be
successfully applied in space application, medicine, high-energy
physics, and security. New proposals are also discussed, for further
improvement of the parameters of the MAPD photodiodes that will be
produced in the coming years.
Climate change impacts on water sustainability of South African crop production
Authors: Bonetti Sara , Sutanudjaja Edwin H , Mabhaudhi Tafadzwanashe , Slotow Rob , Dalin Carole
Published: July 2022

Agricultural production in arid and semi-arid regions is particularly vulnerable to climate change, which, combined with projected food requirements, makes the sustainable management of water resources critical to ensure national and global food security. Using South Africa as an example, we map the spatial distribution of water use by seventeen major crops under current and future climate scenarios, and assess their sustainability in terms of water resources, using the water debt repayment time indicator. We find high water debts, indicating unsustainable production, for potatoes, pulses, grapes, cotton, rice, and wheat due to irrigation in arid areas. Climate change scenarios suggest an intensification of such pressure on water resources, especially in regions already vulnerable, with a country-scale increase in irrigation demand of between 6.5% and 32% by 2090. Future land use planning and management should carefully consider the spatial distribution and local sustainability of crop water requirements to reduce water consumption in water risk hotspots and guarantee long-term food security.
Do Abdominal Binders Prevent Seroma Formation and Recurrent Diastasis Following Abdominoplasty?
Authors: Martins Maria Roberta Cardoso , Moraes Betina Zimmermann Fontes de , Fabri Daniel Capucci , Castro Hugo Alexandre Sócrates de , Rostom Lucas , Ferreira Lydia Masako , Nahas Fabio Xerfan
Published: July 2022

Background

For decades, the postoperative wearing of abdominal binders has been suggested to reduce dead space and prevent mobilization of the musculoaponeurotic layer in an attempt to decrease the risk of seroma formation and recurrent diastasis.

Objectives

This study sought to evaluate whether the postoperative wearing of an abdominal binder provides any additional contribution to the reduction of either seroma formation or recurrent diastasis recti when abdominoplasty is performed with quilting sutures.

Methods

Thirty-four women undergoing abdominoplasty were randomized into 2 groups: the binder group (n = 16) wore abdominal binders during the postoperative period, whereas the control group (n = 18) did not. Ultrasound examination was performed on postoperative days 7 and 14 to assess seroma formation and at 6 months postoperatively to assess recurrence of diastasis recti. A t test for independent samples was applied to compare means between 2 numeric variables. Generalized estimation equation models were used to evaluate seroma volume at different time points for the 2 groups.

Results

No significant differences in seroma volume were found between groups on postoperative days 7 (P = 0.830) and 14 (P = 0.882). Seven cases of subclinical recurrent diastasis were observed by ultrasound examination in the supraumbilical (4 cases) and infraumbilical regions (3 cases), but without significant differences (P = 1.000) between the 2 groups. Recurrent diastasis was not detected during physical examinations.

Conclusions

The postoperative wearing of abdominal binders was not effective in preventing either seroma formation or recurrent diastasis following abdominoplasty with quilting sutures.

Level of Evidence: 2
Machine-designed biotherapeutics: opportunities, feasibility and advantages of deep learning in computational antibody discovery
Authors: Wilman Wiktoria , Wróbel Sonia , Bielska Weronika , Deszynski Piotr , Dudzic Paweł , Jaszczyszyn Igor , Kaniewski Jędrzej , Młokosiewicz Jakub , Rouyan Anahita , Satława Tadeusz , Kumar Sandeep , Greiff Victor , Krawczyk Konrad
Published: July 2022

Antibodies are versatile molecular binders with an established and growing role as therapeutics. Computational approaches to developing and designing these molecules are being increasingly used to complement traditional lab-based processes. Nowadays, in silico methods fill multiple elements of the discovery stage, such as characterizing antibody–antigen interactions and identifying developability liabilities. Recently, computational methods tackling such problems have begun to follow machine learning paradigms, in many cases deep learning specifically. This paradigm shift offers improvements in established areas such as structure or binding prediction and opens up new possibilities such as language-based modeling of antibody repertoires or machine-learning-based generation of novel sequences. In this review, we critically examine the recent developments in (deep) machine learning approaches to therapeutic antibody design with implications for fully computational antibody design.
Statistical challenges in longitudinal microbiome data analysis
Authors: Kodikara Saritha , Ellul Susan , Lê Cao Kim-Anh
Published: July 2022

The microbiome is a complex and dynamic community of microorganisms that co-exist interdependently within an ecosystem, and interact with its host or environment. Longitudinal studies can capture temporal variation within the microbiome to gain mechanistic insights into microbial systems; however, current statistical methods are limited due to the complex and inherent features of the data. We have identified three analytical objectives in longitudinal microbial studies: (1) differential abundance over time and between sample groups, demographic factors or clinical variables of interest; (2) clustering of microorganisms evolving concomitantly across time and (3) network modelling to identify temporal relationships between microorganisms. This review explores the strengths and limitations of current methods to fulfill these objectives, compares different methods in simulation and case studies for objectives (1) and (2), and highlights opportunities for further methodological developments. R tutorials are provided to reproduce the analyses conducted in this review.
De novo molecular design with deep molecular generative models for PPI inhibitors
Authors: Wang Jianmin , Chu Yanyi , Mao Jiashun , Jeon Hyeon-Nae , Jin Haiyan , Zeb Amir , Jang Yuil , Cho Kwang-Hwi , Song Tao , No Kyoung Tai
Published: July 2022

We construct a protein–protein interaction (PPI) targeted drug-likeness dataset and propose a deep molecular generative framework to generate novel drug-likeness molecules from the features of the seed compounds. This framework gains inspiration from published molecular generative models, uses the key features associated with PPI inhibitors as input and develops deep molecular generative models for de novo molecular design of PPI inhibitors. For the first time, quantitative estimation index for compounds targeting PPI was applied to the evaluation of the molecular generation model for de novo design of PPI-targeted compounds. Our results estimated that the generated molecules had better PPI-targeted drug-likeness and drug-likeness. Additionally, our model also exhibits comparable performance to other several state-of-the-art molecule generation models. The generated molecules share chemical space with iPPI-DB inhibitors as demonstrated by chemical space analysis. The peptide characterization-oriented design of PPI inhibitors and the ligand-based design of PPI inhibitors are explored. Finally, we recommend that this framework will be an important step forward for the de novo design of PPI-targeted therapeutics.
Prediction of allosteric druggable pockets of cyclin-dependent kinases
Authors: Ning Shangbo , Wang Huiwen , Zeng Chen , Zhao Yunjie
Published: July 2022

Cyclin-dependent kinase (Cdk) proteins play crucial roles in the cell cycle progression and are thus attractive drug targets for therapy against such aberrant cell cycle processes as cancer. Since most of the available Cdk inhibitors target the highly conserved catalytic ATP pocket and their lack of specificity often lead to side effects, it is imperative to identify and characterize less conserved non-catalytic pockets capable of interfering with the kinase activity allosterically. However, a systematic analysis of these allosteric druggable pockets is still in its infancy. Here, we summarize the existing Cdk pockets and their selectivity. Then, we outline a network-based pocket prediction approach (NetPocket) and illustrate its utility for systematically identifying the allosteric druggable pockets with case studies. Finally, we discuss potential future directions and their challenges.
Systems in Flames: Dynamic Coproduction of Social–Ecological Processes
Authors: Cadenasso Mary L , Rademacher Anne M , Pickett Steward T A
Published: July 2022

Ecologists who study human-dominated places have adopted a social–ecological systems framework to recognize the coproduced links between ecological and social processes. However, many social scientists are wary of the way ecologists use the systems concept to represent such links. This wariness is sometimes due to a misunderstanding of the contemporary use of the systems concept in ecology. We aim to overcome this misunderstanding by discussing the contemporary systems concept using refinements from biophysical ecology. These refinements allow the systems concept to be used as a bridge rather than a barrier to social–ecological interaction. We then use recent examples of extraordinary fire to illustrate the usefulness and flexibility of the concept for understanding the dynamism of fire as a social–ecological interaction. The systems idea is a useful interdisciplinary abstraction that can be contextualized to account for societally important problems and dynamics.
Environmental Discourse Exhibits Consistency and Variation across Spatial Scales on Twitter
Authors: Chang Charlotte H , Armsworth Paul R , Masuda Yuta J
Published: July 2022

Social media platforms, such as Twitter, are an increasingly important source of information and are forums for discourse within and between interest groups. Research highlights how social media communities have amplified movements such as the Arab Spring, #MeToo, and Black Lives Matter. But environmental digital discourse remains underexplored. In the present article, we apply automated text analysis to 200,000 Twitter users in several countries following leading environmental nongovernmental organizations. Some issues such as public action to decarbonize society or species conservation were discussed more intensely than agriculture or marine conservation. Our results illustrate where environmental discourse diverges and converges on Twitter across countries, states, and characteristics, such as political ideology. Using the coterminous United States as a case study, we observed that the prominence of issues varies across states and, in some cases, covaries with political ideology across counties. Our findings show paths forward to characterizing environmental priorities across many issues at unprecedented scale and extent.