bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of cochlea implant stimulation considering dispersive properties of the environment
Authors: Hauser A. , Verhey J. L.
Published: April 2022

A computer numeric algorithm is used to simulate the time course of the electric field around a stimulating electrode of a cochlear implant. The dispersive properties of the surrounding biological tissues, i.e., the frequency-dependent conductivity and dielectric properties, are considered in the simulations. The study focuses on the polarization of auditory nerve tissue. It investigates how the polarization changes with pulse shapes that are typically used in cochlear implants. It is shown that several findings on the effect of pulse shape on the threshold and dynamic range can be predicted on the basis of the mean amount of this polarization. This approach also provides a possible explanation for why a change from a biphasic to triphasic pulse is able to reduce unwanted facial costimulation, which is sometimes observed in cochlear implant users.
The binding of atomic hydrogen on graphene from density functional theory and diffusion Monte Carlo calculations
Authors: Dumi Amanda , Upadhyay Shiv , Bernasconi Leonardo , Shin Hyeondeok , Benali Anouar , Jordan Kenneth D.
Published: April 2022

In this work, density functional theory (DFT) and diffusion Monte Carlo (DMC) methods are used to calculate the binding energy of a H atom chemisorbed on the graphene surface. The DMC value of the binding energy is about 16% smaller in magnitude than the Perdew–Burke–Ernzerhof (PBE) result. The inclusion of exact exchange through the use of the Heyd–Scuseria–Ernzerhof functional brings the DFT value of the binding energy closer in line with the DMC result. It is also found that there are significant differences in the charge distributions determined using PBE and DMC approaches.
Machine learning approach to the Floquet–Lindbladian problem
Authors: Volokitin V. , Meyerov I. , Denisov S.
Published: April 2022

Similar to its classical version, quantum Markovian evolution can be either time-discrete or time-continuous. Discrete quantum Markovian evolution is usually modeled with completely positive trace-preserving maps, while time-continuous evolution is often specified with superoperators referred to as “Lindbladians.” Here, we address the following question: Being given a quantum map, can we find a Lindbladian that generates an evolution identical—when monitored at discrete instances of time—to the one induced by the map? It was demonstrated that the problem of getting the answer to this question can be reduced to an NP-complete (in the dimension N of the Hilbert space, the evolution takes place in) problem. We approach this question from a different perspective by considering a variety of machine learning (ML) methods and trying to estimate their potential ability to give the correct answer. Complimentarily, we use the performance of different ML methods as a tool to validate a hypothesis that the answer to the question is encoded in spectral properties of the so-called Choi matrix, which can be constructed from the given quantum map. As a test bed, we use two single-qubit models for which the answer can be obtained using the reduction procedure. The outcome of our experiment is that, for a given map, the property of being generated by a time-independent Lindbladian is encoded both in the eigenvalues and the eigenstates of the corresponding Choi matrix.
EPR investigation of point defects in HfB2 and their roles in supercapacitor device performances
Authors: Buldu-Akturk Merve , Balcı-Çağıran Özge , Erdem Emre
Published: April 2022

Boron-based materials have various attractive properties and gained increased attention in recent years as promising materials for energy storage applications. Despite vast literature on structural and mechanical properties of transition metal diborides, hafnium diboride (HfB2) in particular, research that addresses the use of HfB2 as an electrode for supercapacitor devices is lacking. Herein, we report both the synthesis and characterization of HfB2 and its electrochemical performance as the electrode for all-in-one symmetric and asymmetric supercapacitor devices. HfB2 powders were synthesized by mechanical activation assisted carbothermal reduction of hafnium oxide and boron oxide precursors. To improve the electrochemical energy storage performance of the electrodes, point defects (either Hf or B vacancies/interstitials) were formed in HfB2 through annealing at different temperatures (1450 and 1650 °C) under a flowing Ar atmosphere. The origin of point defects and their localization on the surface in HfB2 were identified using electron paramagnetic resonance (EPR) spectroscopy and discussed both from chemical and materials point-of-view. The defective HfB2 electrode exhibited higher performance than that of the non-defective one with specific energy and power densities of 0.144 W h kg−1 and 33.3 W kg−1; specific charge–discharge capacities of 0.32 and 0.31 mA h g−1; and 115.5%, 106.2%, and 84.1% retention of the initial capacitances, respectively. The relation between the defect content and the improved supercapacitor performances was explained by employing several structural (x-ray diffractometer and x-ray fluorescence), electronic (EPR), and electrochemical (potentiostatic electrochemical impedance spectroscopy, cyclic voltammetry, galvanostatic cycling with potential limitation) characterization tools.
Swimming of an inertial squirmer array in a Newtonian fluid
Authors: Ouyang Zhenyu , Lin Jianzhong , Phan-Thien Nhan
Published: April 2022

An immersed boundary-lattice Boltzmann method is employed to simulate a squirmer (a classical self-propelled model) array swimming in a Newtonian fluid. The swimming Reynolds number Res is set in the range 0.05 ≤ Res ≤ 5 to study three typical arrays (i.e., the two-squirmer, triangular-squirmer, and quadrilateral-squirmer arrays) in their swimming speed, their power expenditure (P), and their hydrodynamic efficiency (η). Our results show that the two-pusher array with a smaller ds (the distance between the squirmers) yields a slower speed in contrast to the two-puller array, where a smaller ds yields a faster speed at Res ≥ 1 (“pusher” is propelled from the rear and “puller” from the front). The regular triangular-pusher (triangular-puller) array with θ = −60° (the included angle between the squirmers) swims faster (slower) than that with θ = 60°; the quadrilateral-pusher (quadrilateral-puller) array with model 2 swims faster (slower) than model 1 (the models are to be defined later). It is also found that a two-puller array with a larger ds is more likely to become unstable than that with a smaller ds. The triangular-puller array with θ = 60° is more likely to become unstable than that with θ = 60°; the quadrilateral-puller array with model 1 becomes unstable easier than that with model 2. In addition, a larger ds generally results in a less energy expenditure. A faster squirmer array yields a higher η, except for two extraordinarily puller arrays. A quantitative relation for η with ReU > 1 is obtained approximately, in that the increasing ratio of η is proportional to an exponent of the motion Reynolds number ReU.
New Zealand postgraduate medical training by distance for Pacific Island country-based general practitioners: a qualitative study
Authors: Blattner Katharina , Faatoese Allamanda , Smith Mark , Maoate Kiki , Miller Rory , Richards Rosalina
Published: April 2022

Introduction New Zealand health training institutions have an important role in supporting health workforce training programmes in the Pacific Region. Aim To explore the experience of Pacific Island country-based doctors from the Cook Islands, Niue, and Samoa, studying in New Zealand’s University of Otago distance-taught Rural Postgraduate programme. Methods Document analysis (16 documents) was undertaken. Eight semi-structured interviews were conducted with Pacific Island country-based students. Thematic analysis of the interviews was undertaken using the framework method. The two data sources were analysed separately, followed by a process to converge and corroborate findings. Results For Pacific Island countries with no previous option for formal general practice training, access to a recognised academic programme represented a milestone. Immediate clinical relevance and applicability of a generalist medical curriculum with rural remote emphasis, delivered mainly at a distance, was identified as a major strength. Although technologies posed some issues, these were generally easily solved. The main challenges identified related to the provision of academic and other support. Traditional university support services and resources were campus focused and not always easily accessed by this group of students who cross educational pedagogies, health systems and national borders to study in a New Zealand programme. Study for individuals worked best when it was part of a recognised and supported Pacific in-country training pathway. Discussion The University of Otago’s Rural Postgraduate programme is accessible, relevant and achievable for Pacific Island country-based doctors. The programme offers a partial solution for training in general practice for the Pacific region. Student experience could be improved by tailoring and strengthening support services and ensuring their effective delivery.
Elucidation of CKAP4-remodeled cell mechanics in driving metastasis of bladder cancer through aptamer-based target discovery
Authors: Sun Xing , Xie Lin , Qiu Siyuan , Li Hui , Zhou Yangyang , Zhang Hui , Zhang Yibin , Zhang Lin , Xie Tiantian , Chen Yinglei , Zhang Lili , Zhao Zilong , Peng Tianhuan , Liu Jing , Wu Wencan , Zhang Lei , Li Juan , Ye Mao , Tan Weihong
Published: April 2022

Significance

Metastasis generally leads to a dismal prognosis in bladder cancer (BLCA). The mechanical status of the cell membrane has been reported to reflect the potential of the metastatic capacity of cancer cells. However, the molecular profile and corresponding mechanical traits underlying BLCA metastasis remain largely elusive. Our study demonstrates the significance of cytoskeleton-associated protein 4 (CKAP4) in BLCA malignancy through aptamer selection, emphasizes the mechanical dominance of the central-to-peripheral gradient over simply softening or stiffening in cell migration, and shows the role of exosomes in mediating mechanical signaling in BLCA metastasis. Altogether, our work verifies the promising advantages of an aptamer-based approach in cancer research, which ranges from biomarker discovery to the elucidation of biological functions.
Simple, fast, and flexible framework for matrix completion with infinite width neural networks
Authors: Radhakrishnan Adityanarayanan , Stefanakis George , Belkin Mikhail , Uhler Caroline
Published: April 2022

Significance

Matrix completion is a fundamental problem in machine learning that arises in various applications. We envision that our infinite width neural network framework for matrix completion will be easily deployable and produce strong baselines for a wide range of applications at limited computational costs. We demonstrate the flexibility of our framework through competitive results on virtual drug screening and image inpainting/reconstruction. Simplicity and speed are showcased by the fact that most results in this work require only a central processing unit and commodity hardware. Through its connection to semisupervised learning, our framework provides a principled approach for matrix completion that can be easily applied to problems well beyond those of image completion and virtual drug screening considered in this paper.
Estimate of OH trends over one decade in North American cities
Authors: Zhu Qindan , Laughner Joshua L. , Cohen Ronald C.
Published: April 2022

Significance

OH is the critical chemical setting removal rates of local pollutants in the atmosphere. The importance of OH to tropospheric chemistry stands in stark contrast to the absence of long-term measurements. Here we synthesize a machine learning technique, satellite observations, and simulations from a state-of-the-art chemical model to estimate OH trends between 2005 and 2014 in 49 North American cities. Compared to the summertime OH in 2005, the OH in 2014 exhibits changes that range from –17 to +11% in different cities. The variation of OH over one decade can be explained by the chemical regime shifts over the years. The identification of chemical regime, in turn, sheds light on the effective policy for controlling ozone.
Predicting relative efficiency of amide bond formation using multivariate linear regression
Authors: Haas Brittany C. , Goetz Adam E. , Bahamonde Ana , McWilliams J. Christopher , Sigman Matthew S.
Published: April 2022

Significance

Given the ubiquity of amide coupling reactions, understanding the factors which influence the success of the reaction and having means to predict the reaction rate would streamline synthetic efforts. This study outlines a data science–based workflow for effective statistical modeling with sparse experimental data. We demonstrated informed substrate selection, collection of rate data and interpretable molecular descriptors, and statistical model development for amide coupling rates. The resulting statistical models illuminate substrate features that impact rate and allow for the prediction of untested amide coupling rates.
Unusual magnetotransport in twisted bilayer graphene
Authors: Finney Joe , Sharpe Aaron L. , Fox Eli J. , Hsueh Connie L. , Parker Daniel E. , Yankowitz Matthew , Chen Shaowen , Watanabe Kenji , Taniguchi Takashi , Dean Cory R. , Vishwanath Ashvin , Kastner M. A. , Goldhaber-Gordon David
Published: April 2022

Significance

When two sheets of graphene are twisted to the magic angle of 1.1
∘
, the resulting flat moiré bands can host exotic correlated electronic states such as superconductivity and ferromagnetism. Here, we show transport properties of a twisted bilayer graphene device at 1.38
∘
, far enough above the magic angle that we do not expect exotic correlated states. Instead, we see several unusual behaviors in the device’s resistivity upon tuning both charge carrier density and perpendicular magnetic field. We can reproduce these behaviors with a surprisingly simple model based on Hofstadter’s butterfly. These results shed light on the underlying properties of twisted bilayer graphene.
Metabolic reprogramming of tumor-associated macrophages by collagen turnover promotes fibrosis in pancreatic cancer
Authors: LaRue Madeleine M. , Parker Seth , Puccini Joseph , Cammer Michael , Kimmelman Alec C. , Bar-Sagi Dafna
Published: April 2022

Significance

The highly desmoplastic and immunosuppressive microenvironment of pancreatic tumors is a major determinant of the aggressive nature and therapeutic resistance of pancreatic cancer. Therefore, improving our understanding of the mechanisms that regulate the composition and function of the pancreatic tumor microenvironment is critical for the design of intervention strategies for this devastating malignancy. This study identifies a modality for the reprogramming of tumor-associated macrophages involving collagen scavenging followed by a metabolic switch toward a profibrotic paracrine phenotype. These findings establish a molecular framework for the elucidation of regulatory processes that could be harnessed to mitigate the stroma-dependent protumorigenic effects in pancreatic cancer.
Pathogen-induced biosynthetic pathways encode defense-related molecules in bread wheat
Authors: Polturak Guy , Dippe Martin , Stephenson Michael J. , Chandra Misra Rajesh , Owen Charlotte , Ramirez-Gonzalez Ricardo H. , Haidoulis John F. , Schoonbeek Henk-Jan , Chartrain Laetitia , Borrill Philippa , Nelson David R. , Brown James K.M. , Nicholson Paul , Uauy Cristobal , Osbourn Anne
Published: April 2022

Wheat is a widely grown food crop that suffers major yield losses due to attack by pests and pathogens. A better understanding of biotic stress responses in wheat is thus of major importance. The recently assembled bread wheat genome coupled with extensive transcriptomic resources provides unprecedented new opportunities to investigate responses to pathogen challenge. Here, we analyze gene coexpression networks to identify modules showing consistent induction in response to pathogen exposure. Within the top pathogen-induced modules, we identify multiple clusters of physically adjacent genes that correspond to six pathogen-induced biosynthetic pathways that share a common regulatory network. Functional analysis reveals that these pathways, all of which are encoded by biosynthetic gene clusters, produce various different classes of compounds—namely, flavonoids, diterpenes, and triterpenes, including the defense-related compound ellarinacin. Through comparative genomics, we also identify associations with the known rice phytoalexins momilactones, as well as with a defense-related gene cluster in the grass model plant
Brachypodium distachyon
. Our results significantly advance the understanding of chemical defenses in wheat and open up avenues for enhancing disease resistance in this agriculturally important crop. They also exemplify the power of transcriptional networks to discover the biosynthesis of chemical defenses in plants with large, complex genomes.
The ghost of Vulgar Latin
Authors: Versteegh Kees
Published: April 2022

The concept of a colloquial variety of Latin as an intermediate variety between Latin and the Romance languages has a long standing. Sometimes calledVulgarorPopular Latin, this variety is often conceptualized as a discrete linguistic variety, which is held responsible for the changes in the provincial realization of Latin. Since a great deal of evidence for this variety is collected from written texts, studies on the emergence of the Romance languages have tended to ignore the actual process of language acquisition in the provinces of the Roman empire. In the present paper I draw attention to the work of two early scholars, the Italian Celso Cittadini (1533–1627) and the Frenchman Pierre-Nicolas Bonamy (1694–1770), who did concern themselves with the acquisition of Latin, referring to the role of the Roman army in spreading the Latin language throughout the empire. Their suggestions about the process of Latinization can be substantiated with data on the military presence in the provinces of the Roman empire.
Psycholinguistic errors in signed simultaneous interpreting
Authors: Wehrmeyer Ella
Published: April 2022

In this article, errors and repairs in a corpus of English news broadcasts interpreted simultaneously into South African Sign Language are explored from a psycholinguistic perspective according toLevelt’s (1989)cognitive levels (comprehension, conceptualisation, formulation, morphological encoding and articulation). Breaking away from traditional perspectives, the study offers a novel approach to empirical research into sign(ed) language interpreting, with applications relevant to spoken-language interpreting. Most slips involved lemma selection, followed by slips in articulation and conceptualisation (syntactic planning). Significantly fewer errors in comprehension compared to production indicate that professional interpreters have excellent listening skills, although reconceptualising is sometimes problematic. The interpreters mainly repaired incorrect lemma selection and reception errors that resulted in mistranslations, suggesting the existence of a true/false error-detection mechanism, with little attention being paid to other forms of error, possibly owing to time and cognitive pressures. Errors do not increase over time, which suggests cognitive overload rather than fatigue as their cause.
On the status of information structure markers
Authors: Däbritz Chris Lasse
Published: April 2022

The paper at hand deals with morphological marking of information structural relations from the perspective of North-Western Siberian languages. Given many items (morphemes as well as particles and clitics) which have been analyzed as markers of information structure in these languages, I try to discuss whether they indeed mark information structural relations or whether this supposed marking is rather a side effect of other functions expressed. In order to develop criteria for decision marking, I rely on the concepts of sufficiency as well as necessity and sufficient as well as necessary conditions, respectively. Additionally, I argue that the latter can be arranged hierarchically with respect to their reliability for the evaluation of potential markers of information structure, being intertwined with functional and transparency coding principles.
An unexpected role for PD-L1 in front–rear polarization and directional migration
Authors: Sánchez-Álvarez Miguel , del Pozo Miguel A.
Published: April 2022

Programmed cell death-ligand 1 (PD-L1)–mediated T cell inhibition through PD-1 is a key checkpoint frequently exploited by tumors to evade immunity. In this issue, Wang et al. (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202108083) reveal an unexpected role for PD-L1 in promoting tumor cell front–rear polarity and directionally persistent cell migration, independently of PD-1.
Toward an understanding of allogeneic conflict in pregnancy and transplantation
Authors: Durgam Samarth S. , Alegre Maria-Luisa , Chong Anita S.
Published: April 2022

Pregnancy is recognized as a spontaneously acquired state of immunological tolerance by the mother to her semi-allogeneic fetus, but it is a major cause of allosensitization in candidates for organ transplantation. This sensitization, assessed by the presence of anti-HLA IgG, contributes to sex disparity in access to transplantation and increases the risk for rejection and graft loss. Understanding this dual tolerance/sensitization conundrum may lead to new strategies for equalizing access to transplantation among sexes and improving transplant outcomes in parous women. Here, we review the clinical evidence that pregnancy results in humoral sensitization and query whether T cell responses are sensitized. Furthermore, we summarize preclinical evidence on the effects of pregnancy on fetus-specific CD4+ conventional, regulatory, and CD8+ T cells, and humoral responses. We end with a discussion on the impact of the divergent effects that pregnancy has upon alloantigen re-encounter in the context of solid organ transplantation, and how these insights point to a therapeutic roadmap for controlling pregnancy-dependent allosensitization.
Trophoblast antigens, fetal blood cell antigens, and the paradox of fetomaternal tolerance
Authors: Rizzuto Gabrielle , Erlebacher Adrian
Published: April 2022

The paradox of fetomaternal tolerance has puzzled immunologists and reproductive biologists alike for almost 70 yr. Even the idea that the conceptus evokes a uniformly tolerogenic immune response in the mother is contradicted by the long-appreciated ability of pregnant women to mount robust antibody responses to paternal HLA molecules and RBC alloantigens such as Rh(D). Synthesizing these older observations with more recent work in mice, we discuss how the decision between tolerance or immunity to a given fetoplacental antigen appears to be a function of whether the antigen is trophoblast derived—and thus decorated with immunosuppressive glycans—or fetal blood cell derived.
Design and analysis of a wideband and wide angle 3D metamaterial absorber
Authors: Wang Wenjie , Wang Aixia , Liang Jiangang , Wang Zhenxu , Jiang Jinming , Xu Cuilian , Li Yongfeng , Wang Jiafu , Qu Shaobo
Published: April 2022

In this paper, we proposed a three-dimensional (3D) metamaterial absorber joint by lightweight 3D grid structure and traditional magnetic materials, which can achieve wideband and wide-angle perfect absorption at 5–20 GHz. By simulation, the broadband absorption remained almost 90% from 0° to 80° for TM wave. The surface current and power loss distributions were investigated to interpret the physical mechanism of wideband and wide-angle absorption. The broadband and wide-angle absorption were derived from magnetic and electric resonances between the top resistive film, background plane and magnetic loss of magnetic materials. The results proved that different layers of the proposed absorber play different loss roles, and finally contributed to the wideband and wide-angle absorption. The polarization insensitive stability of the proposed absorber was also demonstrated at different polarized angles. The present study provided a new design to achieve a polarization insensitive, wideband and wide-angle absorber. Moreover, the structure absorber has potential applications in other fields, including the solar cell, imaging and detection etc.
Preparation and photoelectric characterization of p-GeSe/p-WS2 heterojunction devices
Authors: Yan Bing , Zhang Guoxin , Ning Bo , Chen Sikai , Zhao Yang , Zhou Dahua , Shi Xuan , Shen Jun , Xiao Zeyun , Zhao Hongquan
Published: April 2022

The construction of van der Waals (vdW) heterojunctions has attracted widespread attention for various strategies in the optoelectronic field due to their band structural advantages. Herein, novel p–p heterojunctions based on p-GeSe and p-WS2 flakes are fabricated on 300 nm-SiO2/Si substrates by means of mechanical exfoliation and micro-area fixed-point transfer of the GeSe flakes onto the WS2 flakes. The thickness and quality of the materials are determined by atomic force microscope and Raman spectroscopy. Considerable photoelectric characteristics are exhibited by exploring the performance of the heterojunctions under a 635 nm laser illumination. The photoresponsivity (

R
λ

), specific detectivity (

D

*

), and external quantum efficiency (

EQE

) of the heterojunctions are measured to be 195.70 mA W−1, 2.879 × 107 Jones, and 38.28%, respectively. The results indicate the strong potential of the p–p type heterojunctions composed of GeSe and WS2 flakes in photoelectric devices, and our work provides parameters and technical support for the development of vdW heterojunction devices.
Analysis of flexochemical effect and its application in scanning probe microscopy
Authors: Zhang Gongxi , Deng Feng , Liu Wenyuan , Shen Shengping
Published: April 2022

Electrochemical processes in solids are affected by the properties of various interfaces, where the flexoelectric effect manifests itself considerably due to the inevitable strong gradient fields. Thus, it is crucial to study the coupling between the electrochemical process and the flexoelectric effect. Based on the continuum theory, we conducted the finite element implementation for the flexochemical effect, being the coupling between flexoelectricity, Vegard effect and chemical reactions. Then, the developed method is employed to investigate the flexochemical effect arising in scanning probe microscopy (SPM), including evaluating the contributions from the flexoelectric effect and Vegard effect to the electromechanical response on material SrTiO3 (STO) in piezoresponse force microscopy (PFM) as well as to mechanical redistribution of oxygen vacancy in STO. It is found that at room temperature the nanoscale electromechanical response of the undoped STO in PFM imaging is mainly induced by the converse flexoelectricity while the contribution of direct Vegard effect is negligible. Furthermore, the contact force exerted by SPM tip in manipulating the redistribution of oxygen vacancies is multifunctional, including diminishing vacancies underneath the contact area and enriching the regions around the tip-surface contact edge and inside the sample below the tip, resulting from the synergy of the converse Vegard effect and the direct flexoelectricity. These analyses explain some experimental observations well. This paper provides a continuum framework for the analysis of electrochemomechanical systems with the flexoelectric effect.
Radiative decay of an emitter due to non-Markovian interactions with dissipating matter
Authors: Jain Kritika , Venkatapathi Murugesan
Published: April 2022

It is known that the more tractable Markovian models of coupling suited for weak interactions may overestimate the Rabi frequency notably when applied to the strong-coupling regime. Here, a more significant consequence of the non-Markovian interaction between a photon emitter and dissipating matter such as resonant plasmonic nanoparticles is described. A large increase of radiative decay and a diminished non-radiative loss is shown, which unravels the origin of unexpected large enhancements of surface-enhanced-Raman-spectroscopy, as well as the anomalous enhancements of emission due to extremely small fully absorbing metal nanoparticles less than 10 nm in dimensions. We construct the mixture of pure states of the coupled emitter-nanoparticle system, unlike conventional methods that rely on the orthogonal modes of the nanoparticle alone.
Summary of the 2021 ICRP workshop on the future of radiological protection
Authors: Rühm W , Clement C , Cool D , Laurier D , Bochud F , Applegate K , Schneider T , Bouffler S , Cho K , Hirth G , Kai M , Liu S , Romanov S , Wojcik A
Published: April 2022

The International Commission on Radiological Protection (ICRP) has embarked on a process to review and revise the current System of Radiological Protection (‘the System’). To stimulate discussion, the ICRP published two open-access articles: one on aspects of the System that might require review, and another on research that might improve the scientific foundation of the System. Building on these articles, the ICRP organized a Workshop on the Future of Radiological Protection as an opportunity to engage in the review and revision of the System. This digital workshop took place from 14 October–3 November 2021 and included 20 live-streamed and 43 on-demand presentations. Approximately 1500 individuals from 100 countries participated. Based on the subjects covered by the presentations, this summary is organized into four broad areas: the scientific basis, concepts and application of the System; and the role of the ICRP. Some of the key topics that emerged included the following: classification of radiation-induced effects; adverse outcome pathway methodologies; better understanding of the dose–response relationship; holistic and reasonable approaches to optimization of protection; radiological protection of the environment; ethical basis of the System; clarity, consistency and communication of the System; application of the System in medicine and application of the principles of justification and optimization of protection.
Adaptive singular value decomposition for bearing fault diagnosis under strong noise interference
Authors: Cui Lingli , Liu Yinhang , Zhao Dezun
Published: April 2022

Singular value decomposition (SVD) is an effective tool for analyzing the signals from mechanical systems and for fault diagnosis, which is a non-parametric signal analysis method free from phase shift and waveform distortion. In SVD, the embedding dimension of the Hankel matrix is an important parameter that directly influences the effectiveness of the SVD. However, the embedding dimension is usually determined by experience, which is quite subjective and limits the applicability of SVD. As such, a novel SVD method, named adaptive SVD (ASVD), is proposed in this paper. In ASVD, novel criteria are defined to obtain the specific embedding dimensions for different mechanical signals by means of numerical simulation. A novel phenomenon, that the singular value pairs change periodically with the step size of half-cycle sampling points, is found and it can be used to calculate specific embedding dimension instead of selecting it from a range using experience. Meanwhile, the envelope spectral amplitude ratio index is developed for addressing the issue of excessive decomposition in classic SVD. Lastly, an ASVD-based bearing fault diagnosis method is proposed to adaptively select useful sub-signals and to detect faults. Both simulated signal and experiment signals, collected from different bearing test rigs are used to verify the effectiveness of the proposed method. The results show that the proposed method has a satisfactory ability to eliminate interference noise and detect bearing fault.
Large-area flexible MWCNT/PDMS pressure sensor for ergonomic design with aid of deep learning
Authors: Zhong Hongchuan , Fu Rongda , Chen Shiqi , Zhou Zaiwei , Zhang Yue , Yin Xiangyu , He Bingwei
Published: April 2022

The achievement of well-performing pressure sensors with low pressure detection, high sensitivity, large-scale integration, and effective analysis of the subsequent data remains a major challenge in the development of flexible piezoresistive sensors. In this study, a simple and extendable sensor preparation strategy was proposed to fabricate flexible sensors on the basis of multiwalled carbon nanotube/polydimethylsiloxane (MWCNT/PDMS) composites. A dispersant of tetrahydrofuran (THF) was added to solve the agglomeration of MWCNTs in PDMS, and the resistance of the obtained MWCNT/PDMS conductive unit with 7.5 wt.% MWCNTs were as low as 180 Ω/hemisphere. Sensitivity (0.004 kPa−1), excellent response stability, fast response time (36 ms), and excellent electromechanical properties were demonstrated within the pressure range from 0 to 100 kPa. A large-area flexible sensor with 8 × 10 pixels was successfully adopted to detect the pressure distribution on the human back and to verify its applicability. Combining the sensor array with deep learning, inclination of human sitting was easily recognized with high accuracy, indicating that the combined technology can be used to guide ergonomic design.
Electromagnetic forces in nanoparticles made of multilayer hyperbolic metamaterials
Authors: Zhu Sheng-Qing , Zhang Yi
Published: April 2022

We theoretically study the electromagnetic forces (optical gradient force, optical torque and vacuum friction) acting on a spherical anisotropic nanoparticle, which can be characterized by multilayer hyperbolic metamaterials (mHMMs). We find three important results about these forces: (i) Firstly, we theoretically demonstrate that the optical gradient force produced on a mHMMs nanoparticle can be flexibly tuned, from pushing the particle to pulling it, just via changing incident angle of illuminating plane light wave. (ii) Secondly, we find the optical torque acting on the mHMMs nanoparticle (its filling factor is around 0.3) can be tuned between positive and negative via changing the incident angle of circularly polarized plane light. Therefore, the rotating mHMMs nanoparticle with designed filling factor can be accelerated or decelerated by the optical torque. (iii) Finally, due to the large fluctuations of dipole polarizability of mHMMs nanoparticle with appropriate filling factor, we propose a new method to obtain the large enhancement of vacuum friction torque by designing the filling factor of the rotating mHMMs nanoparticle.
Heavy-water-based moderator design for an AB-BNCT unit using a topology optimization algorithm
Authors: Chabod Sébastien , Giraud Julien , Hervé Marine , Santos Daniel , Sauzet Nadine
Published: April 2022

Objective. The design of neutron moderators for BNCT treatment units currently relies on parametric approaches, which yield quality results but are ultimately limited by human imagination. Efficient but non-intuitive design solutions may thus be missed out. This limitation needs to be addressed. Approach. To overcome this limitation, we propose to use a topology optimization algorithm coupled with a state-of-the-art Monte-Carlo transport code. This approach recently proved capable of finding complex optimal configurations of particle propagators with limited human intervention. Main results. In this study, we apply this algorithmic solution to optimize some heavy-water neutron moderators for a specific AB-BNCT treatment unit. The moderators thus generated are compact yet succeed in limiting the exposure of patient’s healthy tissues to levels below recommended limits. They present subtle, original geometries inaccessible to standard parametric approaches or human intuition. Significance. This approach could be used to automatically fit the design of a BNCT moderator to the location and shape of the tumor or to the morphology of the patient to be treated, opening a path for more targeted BNCT treatment.
Endoscopy image enhancement method by generalized imaging defect models based adversarial training
Authors: Li Wenjie , Fan Jingfan , Li Yating , Hao Pengcheng , Lin Yucong , Fu Tianyu , Ai Danni , Song Hong , Yang Jian
Published: April 2022

Objective. Smoke, uneven lighting, and color deviation are common issues in endoscopic surgery, which have increased the risk of surgery and even lead to failure. Approach. In this study, we present a new physics model driven semi-supervised learning framework for high-quality pixel-wise endoscopic image enhancement, which is generalizable for smoke removal, light adjustment, and color correction. To improve the authenticity of the generated images, and thereby improve the network performance, we integrated specific physical imaging defect models with the CycleGAN framework. No ground-truth data in pairs are required. In addition, we propose a transfer learning framework to address the data scarcity in several endoscope enhancement tasks and improve the network performance. Main results. Qualitative and quantitative studies reveal that the proposed network outperforms the state-of-the-art image enhancement methods. In particular, the proposed method performs much better than the original CycleGAN, for example, the structural similarity improved from 0.7925 to 0.8648, feature similarity for color images from 0.8917 to 0.9283, and quaternion structural similarity from 0.8097 to 0.8800 in the smoke removal task. Experimental results of the proposed transfer learning method also reveal its superior performance when trained with small datasets of target tasks. Significance. Experimental results on endoscopic images prove the effectiveness of the proposed network in smoke removal, light adjustment, and color correction, showing excellent clinical usefulness.
Improved accuracy of relative electron density and proton stopping power ratio through CycleGAN machine learning
Authors: Scholey Jessica , Vinas Luciano , Kearney Vasant , Yom Sue , Larson Peder Eric Zufall , Descovich Martina , Sudhyadhom Atchar
Published: April 2022

Objective. Kilovoltage computed tomography (kVCT) is the cornerstone of radiotherapy treatment planning for delineating tissues and towards dose calculation. For the former, kVCT provides excellent contrast and signal-to-noise ratio. For the latter, kVCT may have greater uncertainty in determining relative electron density (

ρ

e

) and proton stopping power ratio (SPR). Conversely, megavoltage CT (MVCT) may result in superior dose calculation accuracy. The purpose of this work was to convert kVCT HU to MVCT HU using deep learning to obtain higher accuracy

ρ

e

and SPR. Approach. Tissue-mimicking phantoms were created to compare kVCT- and MVCT-determined

ρ

e

and SPR to physical measurements. Using 100 head-and-neck datasets, an unpaired deep learning model was trained to learn the relationship between kVCTs and MVCTs, creating synthetic MVCTs (sMVCTs). Similarity metrics were calculated between kVCTs, sMVCTs, and MVCTs in 20 test datasets. An anthropomorphic head phantom containing bone-mimicking material with known composition was scanned to provide an independent determination of

ρ

e

and SPR accuracy by sMVCT. Main results. In tissue-mimicking bone,

ρ

e

errors were 2.20% versus 0.19% and SPR errors were 4.38% versus 0.22%, for kVCT versus MVCT, respectively. Compared to MVCT, in vivo mean difference (MD) values were 11 and 327 HU for kVCT and 2 and 3 HU for sMVCT in soft tissue and bone, respectively.

ρ

e

MD decreased from 1.3% to 0.35% in soft tissue and 2.9% to 0.13% in bone, for kVCT and sMVCT, respectively. SPR MD decreased from 1.8% to 0.24% in soft tissue and 6.8% to 0.16% in bone, for kVCT and sMVCT, respectively. Relative to physical measurements,

ρ

e

and SPR error in anthropomorphic bone decreased from 7.50% and 7.48% for kVCT to <1% for both MVCT and sMVCT. Significance. Deep learning can be used to map kVCT to sMVCT, suggesting higher accuracy

ρ

e

and SPR is achievable with sMVCT versus kVCT.
Machine learning for continuous quantum error correction on superconducting qubits
Authors: Convy Ian , Liao Haoran , Zhang Song , Patel Sahil , Livingston William P , Nguyen Ho Nam , Siddiqi Irfan , Whaley K Birgitta
Published: April 2022

Continuous quantum error correction has been found to have certain advantages over discrete quantum error correction, such as a reduction in hardware resources and the elimination of error mechanisms introduced by having entangling gates and ancilla qubits. We propose a machine learning algorithm for continuous quantum error correction that is based on the use of a recurrent neural network to identify bit-flip errors from continuous noisy syndrome measurements. The algorithm is designed to operate on measurement signals deviating from the ideal behavior in which the mean value corresponds to a code syndrome value and the measurement has white noise. We analyze continuous measurements taken from a superconducting architecture using three transmon qubits to identify three significant practical examples of non-ideal behavior, namely auto-correlation at temporal short lags, transient syndrome dynamics after each bit-flip, and drift in the steady-state syndrome values over the course of many experiments. Based on these real-world imperfections, we generate synthetic measurement signals from which to train the recurrent neural network, and then test its proficiency when implementing active error correction, comparing this with a traditional double threshold scheme and a discrete Bayesian classifier. The results show that our machine learning protocol is able to outperform the double threshold protocol across all tests, achieving a final state fidelity comparable to the discrete Bayesian classifier.
Simultaneous 50 cm/10 cm Single-pulse Polarization Observations of PSR J0953+0755
Authors: Rejep Rukiye , Yan Wen-Ming , Wang Na
Published: April 2022

We report on simultaneous single-pulse observations of PSR J0953+0755 at 732 and 3100 MHz made using the Parkes 64-m radio telescope at two epochs. Another non-simultaneous 1369 MHz observation has also been analyzed to compare polarization properties of this pulsar at different frequencies. The previously reported low-level bridge emission between the interpulse and the main pulse is notably present at 732 MHz. However, the bridge emission becomes very weak or undetectable at higher frequencies. The cross-correlation analysis of simultaneous observations indicates that the total intensity of single pulses is highly correlated, which implies the same emission mechanism is responsible for the two frequencies. We confirm that the abrupt position angle jumps are non-orthogonal in this pulsar which probably result from the overlapping emission from two non-orthogonal polarization modes and the separation between different polarization modes is frequency-dependent. At all three frequencies, the dominant modes are clearly associated with negative values of circular polarization, but the association seems unclear for weak modes.
Ultrafast synthetic strategies under extreme heating conditions toward single-atom catalysts
Authors: He Guanchao , Yan Minmin , Gong Haisheng , Fei Huilong , Wang Shuangyin
Published: April 2022

Dispersing atomic metals on substrates provides an ideal method to maximize metal utilization efficiency, which is important for the production of cost-effective catalysts and the atomic-level control of the electronic structure. However, due to the high surface energy, individual single atoms tend to migrate and aggregate into nanoparticles during preparation and catalytic operation. In the past few years, various synthetic strategies based on ultrafast thermal activation toward the effective preparation of single-atom catalysts (SACs) have emerged, which could effectively solve the aggregation issue. Here, we highlight and summarize the latest developments in various ultrafast synthetic strategy with rapid energy input by heating shockwave and instant quenching for the synthesis of SACs, including Joule heating, microwave heating, solid-phase laser irradiation, flame-assisted method, arc-discharge method and so on, with special emphasis on how to achieve the uniform dispersion of single metal atoms at high metal loadings as well as the suitability for scalable production. Finally, we point out the advantages and disadvantages of the ultrafast heating strategies as well as the trends and challenges of future developments.
Air exposure towards stable Li/Li10GeP2S12 interface for all-solid-state lithium batteries
Authors: Weng Wei , Zhou Dong , Liu Gaozhan , Shen Lin , Li Mengqi , Chang Xinshuang , Yao Xiayin
Published: April 2022

Moist air is a great challenge for manufacturing sulfide-based all-solid-state lithium batteries as the water in air will lead to severe decomposition of sulfide electrolytes and release H2S gas. However, different with direct reaction with water, short-period air exposure of Li10GeP2S12 sulfide electrolyte with controlled humidity can greatly enhance the stability of Li10GeP2S12 against lithium metal, thus realizing stable Li10GeP2S12 based all-solid-state lithium metal batteries. During air exposure, partial hydrolysis reaction occurs on the surface of Li10GeP2S12 pellets, rapidly generating a protective decomposition layer of Li4P2S6, GeS2 and Li2HPO3 in dozens of seconds. This ionically conductive but electronically insulation protecting layer can effectively prevent the severe interface reaction between Li10GeP2S12 and lithium metal during electrochemical cycling. The Li/40s-air-exposed Li10GeP2S12/Li cell shows long cycling stability for 1000 h. And the LiCoO2/40s-air-exposed Li10GeP2S12/Li batteries present good rate capability and long cyclic performances, showing capacity retention of 80% after 100 cycles.
Elliptic curves with common torsion 𝑥-coordinates and hyperelliptic torsion packets
Authors: Fu Hang , Stoll Michael
Published: April 2022

We establish a connection between torsion packets on curves of genus 

2
2

and pairs of elliptic curves realized as double covers of the projective line 

P

x
1

\mathbb {P}^1_x

that have many common torsion

x
x

-coordinates. This can be used to show that the set of common torsion

x
x

-coordinates has size at least 

22
22

infinitely often and has

34
34

elements in some cases. We also explain how we obtained the current record example of a hyperelliptic torsion packet on a genus 

2
2

curve.
A simple construction of the dynamical Φ⁴₃ model
Authors: Jagannath Aukosh , Perkowski Nicolas
Published: April 2022

The

Φ
3
4

\Phi ^4_3

equation is a singular stochastic PDE with important applications in mathematical physics. Its solution usually requires advanced mathematical theories like regularity structures or paracontrolled distributions, and even local well-posedness is highly nontrivial. Here we propose a multiplicative transformation to reduce the periodic

Φ
3
4

\Phi ^4_3

equation to a well-posed random PDE. This leads to a simple and elementary proof of global well-posedness, which only relies on Schauder estimates, the maximum principle, and basic estimates for paraproducts, and in particular does not need regularity structures or paracontrolled distributions.