bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and measurement of a tunable metasurface low-frequency radar absorber
Authors: Lopez Tanguy , Lepetit Thomas , Ratni Badreddine , Burokur Shah Nawaz
Published: March 2024

At the turn of the millennium, developments on metasurfaces lead to a significant step forward in the design of radar absorbing structures, especially at lower frequencies, thanks to a reduced thickness. Still, as with other passive impedance matching systems, they remain constrained in their bandwidth-to-thickness ratio. Fortunately, the recent integration of active electronic components onto metasurfaces has multiplied their functionalities, unlocking new ways to overcome these limitations. For instance, using varactor diodes, which act as variable capacitors, an absorbing metasurface can be rendered tunable to cover a frequency range wider than would any passive system of similar thickness. This is a valuable feature when facing modern frequency-hopping radars. However, the bias-dependent resistance introduced by the varactor diodes can compromise the impedance matching throughout the tunable frequency range. This work, therefore, focuses on the design and measurement of a tunable radar absorbing metasurface using varactor diodes, highlighting the necessity for a joint tuning of capacitance and resistance to grant near-perfect absorption over a wide frequency range.
Toward transferable empirical valence bonds: Making classical force fields reactive
Authors: Allen Alice E. A. , Csányi Gábor
Published: March 2024

The empirical valence bond technique allows classical force fields to model reactive processes. However, parametrization from experimental data or quantum mechanical calculations is required for each reaction present in the simulation. We show that the parameters present in the empirical valence bond method can be predicted using a neural network model and the SMILES strings describing a reaction. This removes the need for quantum calculations in the parametrization of the empirical valence bond technique. In doing so, we have taken the first steps toward defining a new procedure for enabling reactive atomistic simulations. This procedure would allow researchers to use existing classical force fields for reactive simulations, without performing additional quantum mechanical calculations.
Synthesis of thin film infinite-layer nickelates by atomic hydrogen reduction: Clarifying the role of the capping layer
Authors: Parzyck C. T. , Anil V. , Wu Y. , Goodge B. H. , Roddy M. , Kourkoutis L. F. , Schlom D. G. , Shen K. M.
Published: March 2024

We present an integrated procedure for the synthesis of infinite-layer nickelates using molecular-beam epitaxy with gas-phase reduction by atomic hydrogen. We first discuss challenges in the growth and characterization of perovskite NdNiO3/SrTiO3, arising from post growth crack formation in stoichiometric films. We then detail a procedure for fully reducing NdNiO3 films to the infinite-layer phase, NdNiO2, using atomic hydrogen; the resulting films display excellent structural quality, smooth surfaces, and lower residual resistivities than films reduced by other methods. We utilize the in situ nature of this technique to investigate the role that SrTiO3 capping layers play in the reduction process, illustrating their importance in preventing the formation of secondary phases at the exposed nickelate surface. A comparative bulk- and surface-sensitive study indicates that the formation of a polycrystalline crust on the film surface serves to limit the reduction process.
Can classical mechanics sense conical intersection?
Authors: Karmakar Sourav , Thakur Saumya , Jain Amber
Published: March 2024

Conical intersection (CI) leads to fast electronic energy transfer. However, Hamm and Stock [Phys. Rev. Lett. 109, 173201 (2012)] showed the existence of a vibrational CI and its role in vibrational energy relaxation. In this paper, we further investigate the vibrational energy relaxation using an isolated model Hamiltonian system of four vibrational modes with two distinctively different timescales (two fast modes and two slow modes). We show that the excitation of the slow modes plays a crucial role in the energy relaxation mechanism. We also analyze the system from a mixed quantum-classical (surface hopping method) and a completely classical point of view. Notably, surface hopping and even classical simulations also capture fast energy relaxation, which is a signature of CI’s existence.
Robust half metallic properties in two-dimensional transition metal borocarbides: TMBC (TM = 3d transition metals)
Authors: Duan Yuanyuan , Sun Yi , Xu Xiaokang , Qureshi Ali Hamza , Liu Yujie , Niu Xianghong , Liu Yongjun , Yao Xiaojing , Zhang Xiuyun
Published: March 2024

Two-dimensional transition metal borocarbides with intrinsic magnetism have garnered significant research attention due to their potential applications in spintronics. Using density functional theory calculations, we designed a type of transition metal borocarbides with two distinct configurations, TMBC-Is and TMBC-IIs (TM = V–Co), and explored their electronic and magnetic properties. Our results demonstrate that all the studied systems exhibit both thermal and kinetic stability. Notably, four systems of MnBC-I/MnBC-II and FeBC-I/FeBC-II are robust ferromagnetic (FM) half metals (HMs) with Curie temperatures of 145, 180, 108, and 315 K. Expect FeBC-II monolayer, FM to antiferromagnetic transition occurs for three other FM HMs under 8%–10% compressive strains, while FM HM to FM semiconductor transition is found for MnBC-II monolayer under 8% tensile strain. These findings provide a promising way to design two-dimensional FM HMs, which hold potential applications in spintronics.
Wall-modeled large eddy simulation in the immersed boundary-lattice Boltzmann method
Authors: Wang Li , Liu Zhengliang , Jin Bruce Ruishu , Huang Qiuxiang , Young John , Tian Fang-Bao
Published: March 2024

This work presents the wall-modeled large eddy simulation (WMLES) in the immersed boundary-lattice Boltzmann method (IB-LBM). Here, the wall model with both diffusive- and sharp-interface immersed boundary methods (IBMs) is incorporated into the IB-LBM to handle the turbulent boundary layer in high Reynolds number turbulent flows. To maintain the numerical stability, two collision models, i.e., multiple-relaxation-time (MRT) and recursive regularized (RR), are implemented. The performance of these models in the WMLES is examined and compared in the simulation of internal and external flows by considering four benchmarks, i.e., turbulent flow in a channel, flow around a hull of submarine, flow around an Ahmed car model, and flow around a circular cylinder. It is found that a diffusive-interface IBM with wall model is capable to achieve excellent results for the simulation of external flows around bluff objects but fails in the simulation of internal flows of underestimating the wall shear stress due to its extra dissipation. The sharp-interface IBM with the wall model predicts the internal flow very well but fails in some simulations of external flow around bluff bodies due to the failure in the separation flow modeling. It is also found that the MRT-LBM is less dissipative than the RR-LBM, but it generates spurious nonphysical noise in the turbulent flows and tends to be unstable at high Reynolds numbers. Therefore, the diffusive-interface IBM with the wall model is more suitable for the external turbulent flow modeling, while its sharp-interface counterpart is more suitable for the internal turbulent flow modeling. The RR-LBM outperforms the MRT-LBM for the better stability and less nonphysical noise.
Spatiotemporal evolution of ultrafast photocarrier dynamics across WS2–ReS2 lateral interface
Authors: Cui Qiannan , Li Yuanyuan , Zhang He , Chang Jianhua , Xu Hua , Xu Chunxiang
Published: March 2024

2D lateral heterostructures possess atomically sharp lateral interfaces, while understanding of their ultrafast photocarrier dynamics from a spatiotemporal viewpoint is rather elusive. In this study, we have investigated the spatiotemporal evolution of photocarrier dynamics across the 1D lateral interface of a WS2–ReS2 2D lateral heterostructure utilizing femtosecond laser pump–probe. The nontrivial band offset across the 1D lateral interface markedly mediates the spatiotemporal photocarrier transfer and transport processes. Subsequently, a hole accumulation region on the WS2 side and an electron accumulation region (1DEG) on the ReS2 side have been spatially identified by correlating ultrafast photocarrier signals. The measured width of the unilateral depletion region is 1360 ± 160 nm. Our work has provided substantial insights into mediated photocarrier dynamics in the 2D lateral heterostructure, which will benefit explorations in 2D interfacial physics and 2D lateral optoelectronic devices.
High-precision weak measurement sensing with adaptability in sensitivity
Authors: Wang Yifan , Zhu Junfan , Wu Jiguo , Ge Rongchun , Gao Fuhua , Zhang Zhiyou
Published: March 2024

In the field of sensing technology, there is a trade-off between sensitivity and dynamic range. This paper proposes a high-precision weak measurement sensing method with flexible sensitivity adjustment to achieve matching between sensitivity and dynamic range. We demonstrate that precise control over sensitivity can be achieved by adjusting the bandwidth and coupling strength of the probe in frequency domain. In the experiment, the sensitivity ranges from 104 to 105RIU−1, and the precision ranges from 10−7 to 10−8 RIU. Additionally, the decomposition of hydrogen peroxide was precisely measured. Our measurement scheme can facilitate broader application of weak measurement technology in precision sensing.
Impact of on-chip gate voltage on the electric properties of NbTiN superconducting nanowire transistor
Authors: Huan Qingchang , Ma Ruoyan , Zhang Xingyu , Feng Zhongpei , Li Yangmu , Xiong Jiamin , Huang Jia , Li Hao , Peng Wei , Zhang Xiaofu , You Lixing
Published: March 2024

In this work, the gate modulation characteristics of superconducting nanowire transistors (SNTs) were investigated under different on-chip gate voltage configurations. By fabricating NbTiN-SNTs with symmetric side gate, we studied the critical current suppression of SNTs under single, opposite, and double voltage gate. We figure out that the gate voltage and leakage current can be adjusted by the gate configuration. Moreover, it revealed an approximately twofold increase in modulation voltage for the opposite gate configuration as compared to the single gate configuration, implying a possible electric field tuned superconductivity. When simultaneously apply voltage on both gates, the onset and offset voltages kept unchanged, but the leakage current is then two times higher than that of single gate. In addition, under all these three types of gate configuration, the suppression of superconductivity coincided with the onset of leakage current, suggesting a potential charge injection mechanism. Our findings demonstrate that both the electric field and charge injection play important roles on the suppression of superconductivity in SNTs, which also contributes to the further optimization and applications of SNT.
Fully visible light controlled neuro-synaptic ReRAM device based on metal oxide heterojunction
Authors: Shrivastava Saransh , Chi Hsiao-Ni , Limantoro Stephen Ekaputra , Juliano Hans , Tseng Tseung-Yuen
Published: March 2024

Photoelectric synaptic devices as a combination of electronic synapse and photodetector are considered as emerging bio-inspired device technologies. These devices have immense potential to conquer the bottleneck of von Neumann architecture based traditional computing systems. In this Letter, we propose an all-oxide based photoelectric neuro-synaptic resistive random access memory device with the structure of ITO/Ga2O3/ZnO/ITO/Glass, in which the conductance states are reversibly tuned by two different wavelengths (405/522 nm) of visible light spectrum. The strength of light pulse is altered to investigate the learning and forgetting phases of the photoelectric response of the device. A basic biomimetic function “learning-forgetting-rehearsal” behavior is imitated up to 20 cycles. Moreover, emulation of some typical synaptic functions such as associative learning and switching between short and long term plasticities indicate the wavelength awareness of the device. Based on the pure optically induced potentiation/depression characteristics, convolutional neural network simulation achieves an overall test accuracy of 82.5% for the classification of Zalando's article images. The noise tolerance capability of neural network is also examined by applying “salt and pepper” noise in high proportion (75%) to corrupt the images. This work may provide a promising step toward the development of transparent electronics in optogenetics-inspired neuromorphic computing.
Dynamical wetting transition of a stretched liquid bridge
Authors: Shao Zhenghao , Gao Peng
Published: March 2024

The liquid bridge is an important model problem in printing processes. We report the experimental results of stretching a highly viscous liquid bridge between two parallel plates. Depending on the stretching speed, a thin liquid bridge exhibits two representative flow regimes. At low stretching speeds, the liquid bridge deforms in a quasi-static manner and no liquid films are observed. When the stretching speed exceeds a critical value, the contact line fails to follow the retracting meniscus, resulting in the deposition of liquid films on the plate. The entrained film is characterized by an annular rim that retracts and grows by collecting the liquid in the film. It is found that the velocity of the receding contact line is weakly decreasing, and the growth of the rim is characterized by a width of wrim∼Ca1/3t1/2, where the capillary number Ca is defined by the stretching velocity and t is the time. The film may not be fully absorbed into the bulk of the liquid bridge before its eventual breakup at high stretching speeds, leading to variations in the liquid transfer ratio of the two plates.
Inverse design of pore wall chemistry and topology through active learning of surface group interactions
Authors: Jiao Sally , Shell M. Scott
Published: March 2024

Design of next-generation membranes requires a nanoscopic understanding of the effect of biologically inspired heterogeneous surface chemistries and topologies (roughness) on local water and solute behavior. In particular, the rejection of small, neutral solutes, such as boric acid, poses a heretofore unsolved challenge. In prior work, a computational inverse design technique using an evolutionary optimization successfully uncovered new surface design strategies for optimized transport of water over solutes in smooth, model pores consisting of two surface chemistries. However, extending such an approach to more complex (and realistic) scenarios involving many surface chemistries as well as surface roughness is challenging due to the expanded design space. In this work, we develop a new approach that uses active learning to optimize in a reduced feature space of surface group interactions, finding parameters that lead to their assembly into ordered, optimal patterns. This approach rapidly identifies novel surface functionalizations that maximize the difference in water and boric acid transport through the nanopore. Moreover, we find that the roughness of the nanopore wall, independent of its chemistry, can be leveraged to enhance transport selectivity: oscillations in the pore wall diameter optimally inhibit boric acid transport by creating energetic wells from which the solute must escape to transport down the pore. This proof-of-concept demonstrates the potential for active learning strategies, in concert with molecular simulations, to rapidly navigate complex design spaces of aqueous interfaces and is promising as a tool for engineering water-mediated surface interactions for a broad range of applications.
The origin of anomalous mass-dependence of thermal conductivity in Janus XBAlY (X = Se, S, Te; Y = S, Se, O; X ≠ Y) monolayers
Authors: Yuan Guotao , Ouyang Yulou , Tan Rui , Yao Yongsheng , Zeng Yujia , Tang Zhenkun , Zhang Zhongwei , Chen Jie
Published: March 2024

Owing to the unique asymmetric geometry, Janus monolayer compounds exhibit various exotic thermal properties and have promising applications in thermal management. In this study, we combine machine learning potentials and the phonon Boltzmann transport equation to perform a comparative study of the thermal transport properties in Janus XBAlY (X = Se, S, Te; Y = S, Se, O; X ≠ Y) monolayers. Our findings unveil a thermal conductivity (κp) ranking as SeBAlS > TeBAlO > SBAlSe, contradicting the conventional expectation that a higher κp is typically observed when the average atomic mass is smaller. At room temperature, the κp of SeBAlS is 174 Wm−1 K−1, which is 4.8 times that of SBAlSe when considering three-phonon scattering processes. Moreover, the consideration of four-phonon scatterings does not alter such ranking. The anomalous κp phenomenon was explained through a detailed analysis of the phonon–phonon scattering mechanism, phonon bandgap, phonon anharmonicity, and chemical bond strength. This study highlights the intricate relationship between atomic mass, bonding characteristics, and thermal properties, offering insights for designing Janus materials with tailored thermal conductivity.
Machine-learning-assisted searching for thermally conductive polymers: A mini review
Authors: Hu Yinglong , Wang Qi , Ma Hao
Published: March 2024

Polymers, known for their lightweight, high strength, and ease of processing, serve as a key component in engineering materials. Polymers with high thermal conductivity (TC) present enormous potential applications in thermal management for high-performance electronic devices. However, the discovery of thermally conductive polymers is still in a time-consuming and labor-intensive trial-and-error process, which undoubtedly hinders the progress in related applications. Fortunately, machine learning (ML) enables to overcome this obstacle by building precise models to predict the TC of polymers through learning from a large volume of data and it can quickly identify polymers with high TC and provide significant insights to guide further design and innovation. In this mini review, we briefly describe the general process of using ML to predict polymers with high TC and then give guidance for the selection and utilization of three important components: database, descriptor, and algorithm. Furthermore, we summarize the predicted thermally conductive single polymer chains, amorphous polymers, and metal-organic frameworks via ML and identify the key factors that lead to high TC. Finally, we touch on the challenges faced when utilizing ML to predict the TC of polymer and provide a foresight into future research endeavors.
Characterisation of social media conversations on syphilis: an unobtrusive observational study
Authors: Dawson Abby C. , Fitzpatrick Alyssa K. , Matthews Janet M. , Nguyen Andrew A. K. , Papanaoum Kelly , Smith Justine R.
Published: March 2024

Background Conversations around disease conducted through social media provide a means for capturing public perspectives that may be useful in considering public health approaches. Syphilis is a sexually transmitted disease that is re-emerging. We sought to characterise online discourse on syphilis using data collected from the social media platform, Twitter. Methods We extracted English-language tweets containing the word ‘syphilis’ posted on Twitter in 2019. Tweet identification number and URL, date and time of posting, number of retweets and likes, and the author’s screen name, username and biographical statement were included in the dataset. A systematically sampled 10% subset of the data was subjected to qualitative analysis, involving categorisation on content. All tweets assigned to the category of medical resource were assessed for clinical accuracy. The engagement ratio for each category was calculated as (retweets + likes):tweets. Results In 2019, 111,388 tweets mentioning syphilis were posted by 69,921 authors. The most frequent content category – totalling 5370 tweets (48%) – was a joke. Of 1762 tweets (16%) categorised as a medical resource, 1484 (84%) were medically correct and 240 (14%) were medically incorrect; for 38 (2%), medical accuracy could not be judged from the information posted. Tweets categorised as personal experiences had the highest engagement ratio at approximately 19:1. Medical resource tweets had an engagement ratio of approximately 7:1. Conclusions We found medical information about syphilis was limited on Twitter. As tweets about personal experiences generate high engagement, coupling an experience with information may provide opportunity for public health education.
Multiple forces facilitate the aquatic acrobatics of grasshopper and bioinspired robot
Authors: Song Yi , Wang Huan , Dai Zhendong , Ji Aihong , Wu Huaping , Gorb Stanislav N.
Published: March 2024

Aquatic locomotion is challenging for land-dwelling creatures because of the high degree of fluidity with which the water yields to loads. We surprisingly found that the Chinese rice grasshopper
Oxya chinensis
, known for its terrestrial acrobatics, could swiftly launch itself off the water’s surface in around 25 ms and seamlessly transition into flight. Biological observations showed that jumping grasshoppers use their front and middle legs to tilt up bodies first and then lift off by propelling the water toward the lower back with hind legs at angular speeds of up to 18°/ms, whereas the swimming grasshoppers swing their front and middle legs in nearly horizontal planes and move hind legs less violently (~8°/ms). Force measurement and model analysis indicated that the weight support could be achieved by hydrostatics which are proportionate to the mass of the grasshoppers, while the propulsions for motion are derived from the controlled limb–water interactions (i.e., the hydrodynamics). After learning the structural and behavioral strategies of the grasshoppers, a robot was created and was capable of swimming and jumping on the water surface like the insects, further demonstrating the effectiveness of decoupling the challenges of aquatic locomotion by the combined use of the static and dynamic hydro forces. This work not only uncovered the combined mechanisms responsible for facilitating aquatic acrobatics in this species but also laid a foundation for developing bioinspired robots that can locomote across multiple media.
m6Am methyltransferase PCIF1 negatively regulates ciliation by inhibiting BICD2 expression
Authors: Xie Shanshan , Kuang Wenjun , Guo Mengzhe , Yang Feng , Jin Hao , Chen Xiying , Yi Li , Huo Chunxiao , Xu Zhangqi , Lin Aifu , Liu Wei , Mao Jianhua , Shu Qiang , Zhou Tianhua
Published: March 2024

N6, 2′-O-dimethyladenosine (m6Am) is a widespread RNA modification catalyzed by the methyltransferase PCIF1 (phosphorylated CTD interacting factor 1). Despite its prevalence, the biological functions of m6Am in RNA remain largely elusive. Here, we report a critical role of PCIF1-dependent m6Am RNA modification in ciliogenesis in RPE-1 cells. Our findings demonstrate that PCIF1 acts as a negative regulator of ciliation through its m6Am methyltransferase activity. A quantitative proteomic analysis identifies BICD2 as a downstream target of PCIF1, with PCIF1 depletion resulting in a significant increase in BICD2 levels. BICD2 depletion leads to a significant reduction in ciliation. Crucially, the ciliary phenotype in PCIF1-depleted cells is reversed upon BICD2 knockdown. Further investigations reveal that PCIF1 regulates BICD2 protein levels through its m6Am catalytic activity, which reduces the stability and translation efficiency of BICD2 mRNA. Single-base resolution LC-MS analysis identifies the m6Am site on BICD2 mRNA modified by PCIF1. These findings establish the essential involvement of PCIF1-dependent m6Am modification in ciliogenesis.
Theoretical modeling and experimental investigation of in-phase resonant MEMS mirrors with cascaded structures
Authors: Chen Wenhao , Luo Huahuang , Tavakkoli Hadi , Duan Mingzheng , Piyawattanametha Wibool , Lee Yi-Kuen
Published: March 2024

This paper proposes an efficient nonlinear one-dimensional (1D) compact mass-damper-spring model to predict the dynamic response of electrostatic resonant micro-electro-mechanical system (MEMS) mirrors with cascaded structures. The time-dependent damping moment due to viscous shear and pressure drag is computed using semi-empirical analytical equations for comb-drive structures and device frames. Nonlinear electrostatic force induced by the comb drives is efficiently acquired based on the hybrid method. The optimized device is fabricated using MEMS fabrication processes based on a 4-inch silicon-on-insulator wafer. The proposed compact model with the measured key parameters from the fabricated device shows excellent capability to accurately predict nonlinear dynamic responses of the fabricated device, including parametric excitation and hysteretic frequency response, with an average error of less than 5%. In particular, our 1D model is three orders of magnitude faster than the conventional finite element method model (0.8 s versus 1 h), enabling efficient system-level optimization of the critical design parameters. Based on the parametric study, electrode gap distance and torsion spring width are found to be two critical design parameters and dimensional analysis is conducted for design optimization with scan angle enhancing from 16.8° to 24° compared with the first design.
A novel sonoelectrochemical approach for preparing of ZnO nanoparticles
Authors: Quynh Pham Huong , Trang Hoang Minh , Trung Nguyen Thanh , Dinh Nguyen Nang , Van Thanh Dang , Anh Le Phuoc , Luyen Nguyen Thi , Van Nguyen Thi Khanh
Published: March 2024

A novel, rapid, and facile method for one-step sonoelectrochemical synthesis of zinc oxide nanoparticles (UEZ) was introduced in this study. The optimum operating parameters have been selected at a voltage of 7.5 V, KCl concentration of 0.5 M, and the reaction time of 60 min. The as-prepared UEZ were characterized by XRD, SEM, and HRTEM. It was found that the UEZ has a hexagonal wurtzite structure with high crystalline quality, good purity, a size range of 30–100 nm, and good photocatalytic degradation of methylene blue. This work provides a facile route for large-scale synthesizing ZnO nanoparticles via anodization.
Biosynthesis and antibacterial activity of ZnO nanoparticles using Buchanania obovata fruit extract and the eutectic-based ionic liquid
Authors: Jabbar Kadhim Qasim , Barzinjy Azeez Abdullah
Published: March 2024

The fruit extract of Buchanania obovata and the eutectic-based ionic liquid were utilized, in an eco-friendly, inexpensive, simple method, for synthesizing zinc oxide nanoparticles (ZnO NPs). The influence of the reducing, capping and stabilizing agents, in both mediums, on the structure, optical, and morphological properties of ZnO NPs was extensively investigated. The surface plasmon resonance peaks were observed at 340 nm and 320 nm for the fruit-based and the eutectic-based ionic liquid mediums, respectively, indicating the formation of ZnO NPs. XRD results confirmed the wurtzite structure of the ZnO NPs, exhibiting hexagonal phases in the diffraction patterns. The SEM and TEM images display that the biosynthesized ZnO NPs exhibit crystalline and hexagonal shape, with an average size of 40 nm for the fruit-based and 25 nm for the eutectic-based ionic liquid. The Brunauer–Emmett–Teller (BET) surface area analysis, revealed a value ∼13 m2 g−1 for ZnO NPs synthesized using the fruit extract and ∼29 m2 g−1 for those synthesized using the eutectic-based ionic liquid. The antibacterial activity of the biosynthesized ZnO NPs was assessed against clinically isolated Gram-negative (E. coli) and Gram-positive (S. aureus) bacterial strains using the inhibition zone method. The ZnO NPs produced from the eutectic-based ionic liquids confirmed superior antibacterial activity against both S. aureus and E. coli compared to those mediated by the utilized fruit extract. At a concentration of 1000, the eutectic-based ionic liquid mediated ZnO NPs displayed a maximum inhibition zone of 16 mm against S. aureus, while against E. coli, a maximum inhibition zone of 15 mm was observed using the fruit extract mediated ZnO NPs. The results of this study showed that the biosynthesized ZnO NPs can be utilized as an efficient substitute to the frequently used chemical drugs and covering drug resistance matters resulted from continual usage of chemical drugs by users.
Development of non-invasive flexible directional microwave ablation for central lung cancer: a simulation study
Authors: Fang Zheng , Wu Chen , Cao Lin , Wang Tao , Hong Xiaowu , Moser Michael A.J. , Zhang Wenjun , Zhang Bing
Published: March 2024

Transbronchial microwave ablation (MWA) with flexible antennas has gradually become an attractive alternative to percutaneous MWA for lung cancer due to its characteristic of non-invasiveness. However, flexible antennas for the precision ablation of lung tumors that are adjacent to critical bronchial structures are still not available. In this study, a non-invasive flexible directional (FD) antenna for early stage central lung tumors surrounding the bronchia was proposed. A comprehensive numerical MWA model with the FD antenna was developed in a real human-sized left lung model. The structure of the antenna and the treatment protocol were optimized by a generic algorithm for the precision ablation of two cases of early stage central lung cancer (i.e. spherical-like and ellipsoidal tumors). The electromagnetic efficiency of the optimized antenna was also improved by implementing an optimized

π

-matching network for impedance matching. The results indicate that the electromagnetic energy of MWA can be restricted to a particular area for precision ablation of specific lung tumors using the FD antenna. This study contributes to the field of lung cancer management with MWA.
A novel rotary ultrasonic motor based on multiple Langevin transducers: design, simulation, and experimental investigation
Authors: Ma Xinchi , Yang Ying , Qiu Jianmin , Zhang Jiyang , Vasiljev Piotr , Wu Jintao , Mazeika Dalius , Zhao Lei , Borodinas Sergejus , Liu Jikui
Published: March 2024

Traveling wave rotary ultrasonic motors (TRUSMs) have been applied in optical systems, robotics, biomedical and other fields. However, the disadvantages such as short working life, driving performance degradation, and low energy utilization significantly limit the long-term and stable operation of TRUSMs in advanced fields like aerospace mechanisms. To address the above issues, a novel rotary ultrasonic motor based on multiple Langevin transducers is proposed in this paper. First, the structural design, driving principle and general design criteria are described in detail. Then, the structural parameters are optimized by finite element simulation analysis. Second, a prototype is assembled controllably. Subsequently, the impedance test and vibration measurement are carried out. The results show that the traveling wave is successfully generated on the tooth-ring, and all the Langevin transducers are excited to the first-order longitudinal vibration modes, which strongly verify the correctness of design principle. Finally, the driving performance experiment is carried out. The experimental results show that the no-load speed is 62 r min−1 under the pre-pressure of 10 N. The stalling torque is 0.94 N m at the driving voltage of 500 Vp-p. The response characteristics show that the start/stop time are 4.6/5.5 ms, and the angular displacement resolution of clockwise/counterclockwise driving are 6.7/10.2 μrad. The motor proposed in this paper not only exhibits relatively high output performance with excellent vibration characteristics, but also maintains compactness of the structure. The sandwiched structure design effectively avoids the problem that the bonded-type piezoceramic rings in conventional TRUSMs are prone to damage or fall-off when vibrating for a long time. Furthermore, the general design criteria provide a new approach to develop high performance rotary ultrasonic motors. The proposed novel ultrasonic motor is expected to meet the demand for long-term and stable operation in aerospace mechanisms.
Muscle-inspired stiffness-tunable flexible fiber jamming structure for wearable robots
*
Authors: Ma Junlin , Chen Diansheng , Liu Zhe , Li Jialing , Zeng Zihan , Yin Yingxitong , Zhang Xianglin , Shu Chen , Zhu Yaohui , Fu Zhihan , Jiang Yongkang
Published: March 2024

Soft robotics have found their tremendous application prospects in wearable robots due to the inherent compliance of soft materials when interacting with human bodies. However, the limited load-bearing and output capabilities impeded their application in real world. Variable stiffness design contributes to tackling this problem by enhancing the overall structural rigidity. Nevertheless, most of current jamming-based variable stiffness structures realize their stiffness enhancement by squeezing discrete rigid elements, resulting in the loss of structural compliance in the high stiffness state, which could significantly reduce the deformability and even injure the individuals when utilized in wearable robots. In this paper, we propose a muscle-inspired stiffness-continuously-adjustable flexible fiber jamming (FFJ) structure for soft wearable robots. The FFJ structure can achieve continuous stiffness-variation by controlling the fiber overlapping length, which maintains stretchability even in the high stiffness state. We provide a theoretical model to analyze the mechanical performance of the proposed FFJ structure with different design parameters, and verify the model experimentally. The preliminary results show that we achieved 9 times of stiffness enhancement of the proposed FFJ structure by controlling the vacuum pressure, and the maximum tensile stiffness is 4.1 N mm−1. We further demonstrated the effectiveness of the proposed FFJ structure on wearable robots in three different working scenarios: active finger rehabilitation, active elbow rehabilitation, and passive trunk support. The results show that the FFJ structure was able to provide controllable impedance force for active finger/elbow rehabilitation, and help support the human body during long-term labor. This work broadens the frontiers of soft wearable robots and leads a way to the future design of soft and strong robots and devices.
A new ER valve composed of multilayer mesh electrodes
Authors: Xu Luning , Zhang Jiahui , Huang Jingyu , Han Li , Shen Rong , Lu Kunquan
Published: March 2024

In many cases, ER valves are required to be used at lower operating voltages. For example, to develop a two-dimensional Braille matrix display, it is necessary to lay out many ER valves and control each Braille dot independently. If the commonly used parallel plate electrodes are applied, a low voltage can only be used when the electrode gap is very small, which will make the ER valve flow resistance very large, thus making it difficult to achieve effective control. A new type of ER valve composed of multilayer mesh electrodes was designed, which are arranged vertically in the direction of ER fluid flow. The flow rate of the ER valve is determined by the opening ratio of the mesh electrodes. This type of mesh electrode results in a more complex electric field distribution, which has a different action pattern on ER fluid yield stress compared to parallel electrodes. The non-uniform electric field generated by mesh electrodes under different operating voltages was simulated using COMSOL software, and the pressure drops of ER valves with various sizes of mesh electrodes under different voltages were experimentally investigated. The results indicate that the longitudinal electric field component plays a dominant role, and the stress of the ER fluid exhibits a periodic and gradient distribution. This valve exhibits good ER performance when the applied voltage is much lower than that of parallel electrodes. At the same time, the flow rate of the ER valve can be increased by enlarging the opening ratio of the mesh electrodes. Even if the applied voltage is 180 V, the pressure drop of the ER valve is large enough and the operation stability is good. This new type of ER valve makes the device small in size, easy to control intelligently and low cost. Multilayer mesh electrodes also have universal application value in ER technology.
MicroRNA guardians of the posterior cingulate cortex delay cognitive deterioration in elders
Authors: Soreq Hermona
Published: March 2024

This scientific commentary refers to ‘MicroRNA profiles of pathology and resilience in posterior cingulate cortex of cognitively intact elders’, by Kelley et al. (https://doi.org/10.1093/braincomms/fcae082).
Dissociating reading and auditory comprehension in persons with aphasia
Authors: Harrington Rachael M , Kristinsson Sigfus , Wilmskoetter Janina , Busby Natalie , den Ouden Dirk , Rorden Chris , Fridriksson Julius , Bonilha Leonardo
Published: March 2024

Language comprehension is often affected in individuals with post-stroke aphasia. However, deficits in auditory comprehension are not fully correlated with deficits in reading comprehension and the mechanisms underlying this dissociation remain unclear. This distinction is important for understanding language mechanisms, predicting long-term impairments and future development of treatment interventions. Using comprehensive auditory and reading measures from a large cohort of individuals with aphasia, we evaluated the relationship between aphasia type and reading comprehension impairments, the relationship between auditory versus reading comprehension deficits and the crucial neuroanatomy supporting the dissociation between post-stroke reading and auditory deficits. Scores from the Western Aphasia Battery—Revised from 70 participants with aphasia after a left-hemisphere stroke were utilized to evaluate both reading and auditory comprehension of linguistically equivalent stimuli. Repeated-measures and univariate ANOVA were used to assess the relationship between auditory comprehension and aphasia types and correlations were employed to test the relationship between reading and auditory comprehension deficits. Lesion-symptom mapping was used to determine the dissociation of crucial brain structures supporting reading comprehension deficits controlling for auditory deficits and vice versa. Participants with Broca’s or global aphasia had the worst performance on reading comprehension. Auditory comprehension explained 26% of the variance in reading comprehension for sentence completion and 44% for following sequential commands. Controlling for auditory comprehension, worse reading comprehension performance was independently associated with damage to the inferior temporal gyrus, fusiform gyrus, posterior inferior temporal gyrus, inferior occipital gyrus, lingual gyrus and posterior thalamic radiation. Auditory and reading comprehension are only partly correlated in aphasia. Reading is an integral part of daily life and directly associated with quality of life and functional outcomes. This study demonstrated that reading performance is directly related to lesioned areas in the boundaries between visual association regions and ventral stream language areas. This behavioural and neuroanatomical dissociation provides information about the neurobiology of language and mechanisms for potential future treatment interventions.
Stereoselective synthesis of multi-functionalized chiral silacyclopentanes
Authors: Kuroo Akihiro , Igawa Kazunobu , Tomooka Katsuhiko
Published: March 2024

We have synthesized multifunctionalized silacyclopentanes in a highly selective manner from enantioenriched silacyclopentenol, which is readily accessible from achiral silacyclopentene oxide by enantioselective β-elimination. Functionalization at C2, C4, and C5 positions of silacyclopentenol was achieved based on the regio- and stereoselective nucleophilic substitution reaction of epoxides.
Treatment of Multidrug-resistant or Rifampicin-resistant Tuberculosis With an All-oral 9-month Regimen Containing Linezolid or Ethionamide in South Africa: A Retrospective Cohort Study
Authors: Morgan Hannah , Ndjeka Norbert , Hasan Tasnim , Gegia Medea , Mirzayev Fuad , Nguyen Linh N , Schumacher Samuel , Schlub Timothy E , Naidoo Kogieleum , Fox Greg J
Published: March 2024

Background

In 2019, the South African tuberculosis program replaced ethionamide with linezolid as part of an all-oral 9-month regimen. We evaluated treatment outcomes for patients assigned to regimens including linezolid in 2019 and ethionamide in 2017.

Methods

This retrospective cohort study included patients treated for multidrug-resistant/rifampicin-resistant tuberculosis throughout South Africa between 1 January and 31 December 2017 and 1 January to 31 December 2019. The cohort treated with a 9-month regimen containing ethionamide for four months, was compared with a cohort treated with a 9-month regimen containing linezolid for 2 months. The regimens were otherwise identical. Inverse probability weighting of propensity scores was used to adjust for potential confounding. A log-binomial regression model was used to estimate adjusted relative risk (aRR) comparing 24-month outcomes between cohorts including treatment success, death, loss to follow up, and treatment failure. Adverse event data were available for the linezolid cohort.

Findings

In total, 817 patients were included in the cohort receiving ethionamide and 4244 in the cohort receiving linezolid. No evidence for a difference was observed between linezolid and ethionamide regimens for treatment success (aRR = 0.96, 95% confidence interval [CI] .91–1.01), death (aRR = 1.01, 95% CI .87–1.17) or treatment failure (aRR = 0.87, 95% CI .44–1.75). Loss to follow-up was more common in the linezolid group, although estimates were imprecise (aRR = 1.22, 95% CI .99–1.50).

Conclusions

No significant differences in treatment success and survival were observed with substitution of linezolid for ethionamide as a part of an all-oral 9-month regimen. Linezolid is an acceptable alternative to ethionamide in this shorter regimen for treatment of multidrug-resistant/rifampicin-resistant tuberculosis.
Eosinophilic esophagitis prevalence, incidence, and presenting features: a 22-year population-based observational study from southwest Sweden
Authors: Plate J , Söderbergh T , Bergqvist J , Lingblom C , Bergquist H , Larsson H
Published: March 2024

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition of the esophagus that affects both children and adults. Symptoms in adults are mainly esophageal dysphagia, which ranges from mild symptoms to acute food bolus obstruction of the esophagus. Diagnosis is defined as symptoms of esophageal dysfunction and ≥ 15 eosinophils/high power field (HPF) in at least one of the biopsies taken from the esophagus. EoE appears to be increasing in both prevalence and incidence. The aim of this study was to investigate the prevalence, incidence, and presenting symptoms of patients with EoE within the catchment area of Northern Älvsborg County Hospital in Trollhättan. Patient records with the ICD code of EoE between 2012 and 2022 and pathology reports from esophageal biopsies from 2000–2022 were examined. Patients with symptoms of esophageal dysfunction and > 15 eosinophils/HPF were classified as having EoE. In total, 409 EoE patients (379 adults and 30 children) fulfilled the diagnostic criteria during the follow-up period. The overall prevalence was 113 cases/100 000 inhabitants (adults 127/100 000 and children 57/100 000) at 31 December 2022. The incidence was 7/100 000 and increased during the observation period. At diagnosis, 46% of the adults and 11% of the children had a history of acute bolus obstruction requiring hospitalization, while 51% of adults and 22% of children exhibited endoscopic findings of fibrosis. The prevalence of EoE is significantly higher than that generally reported in an area of southwest Sweden. The results indicate that the incidence is increasing; however, whether this is due to an actual increase or heightened awareness of EoE is inconclusive. Acute bolus obstruction is a common presenting symptom among EoE patients and is most likely an effect of late diagnosis.
Frailty in the cardiac intensive care unit: assessment and impact
Authors: Moumneh Mohamad B , Jamil Yasser , Kalra Kriti , Ijaz Naila , Campbell Greta , Kochar Ajar , Nanna Michael G , van Diepen Sean , Damluji Abdulla A
Published: March 2024

Frailty, a clinical syndrome of increased vulnerability, due to diminished cognitive, physical, and physiological reserves is a growing concern in the cardiac intensive care unit (CICU). It contributes to morbidity, mortality, and complications and often exerts a bidirectional association with cardiovascular disease. Although it predominately affects older adults, frailty can also be observed in younger patients <65 years of age, with approximately 30% of those admitted in CICU are frail. Acute cardiovascular illness can also impair physical and cognitive functioning among survivors and these survivors often suffer from frailty and functional declines post-CICU discharge. Patients with frailty in the CICU often have higher comorbidity burden, and they are less likely to receive optimal therapy for their acute cardiovascular conditions. Given the significance of this geriatric syndrome, this review will focus on assessment, clinical outcomes, and interventions, in an attempt to establish appropriate assessment, management, and resource utilization in frail patients during and after CICU admission.
Introduction to the special issue: evolutionary and biopsychosocial perspectives on sickness communication
Authors: Shattuck Eric C , Boyle Chloe C
Published: March 2024

Here, we introduce the EMPH special issue on Evolutionary and Biopsychosocial Perspectives on Sickness Communication. This Commentary provides an overview of each article and places them in the wider context of sickness as a social phenomenon with verbal and nonverbal signals. This Commentary, and the special issue, in general, calls for greater attention to these signals that can affect pathogen transmission and may be at the evolutionary root of our caregiving systems and behaviours.
Succeeding without belonging? A double comparison of migrants’ socio-economic attainment and national belonging across origin and residence countries
Authors: Geurts Nella , Phalet Karen
Published: March 2024

When is migrants’ socio-economic attainment associated with enhanced national belonging to their residence country? Drawing on a large-scale survey, we compare migrants from the same 10 origin countries across Denmark, Germany, and the Netherlands. We exploit this double comparison across origin groups and residence countries to contextualize mixed findings of positive, negative, and null associations between migrants’ socio-economic attainment and national belonging in earlier research. We introduce the notion of ethnic boundaries to situate when migrants’ socio-economic attainment and belonging are positively or negatively associated. We examine how migrants’ socio-economic attainment interacts with contextual variation in ethnic boundaries and with individual-level variation in perceptions of ethnic boundaries based on perceived group discrimination. Multi-group structural equation models show that migrants’ socio-economic attainment is often decoupled from national belonging. However, they also reveal crucial contextual variation as same-origin migrants can succeed socio-economically with or without feeling belonging in different residence countries. At the individual level, perceived group discrimination conditions this association, so that socio-economic attainment translates into more national belonging only when perceptions of discrimination are low. Our comparative findings of contingent national belonging thereby challenge existing assumptions that associations between socio-economic attainment and national belonging are linear and that ethnic boundaries in European migration contexts are rigid.