bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anomalies in the magnetostrictive modulation of love surface acoustic waves
Authors: Aguilera J. D. , Loriente R. , Soria L. , Begue A. , Ranchal R. , Gràcia I. , Vallejos S. , Hernando A. , Marín P. , Presa P. de la , Matatagui D. 
Published: February 2024

A magnetic surface acoustic wave (SAW) sensor is built by growing a 100 nm galfenol (Fe72Ga28) film by sputtering between the interdigitated transducers of a SAW delay line. Love waves are produced when the shear waves excited on the piezoelectric substrate are guided by a 3.1 μm layer of amorphous SiO2. Due to the magnetostrictive nature of galfenol deposited on top, the application of magnetic fields modulates the propagation of the mechanical excitations along the sensor by the strain coupling. By introducing the delay line in a feedback loop circuit, these changes are studied as resonant frequency variations. Magnetic field cycles of ±40 mT are applied to the sample and the resonant frequency shift is tracked simultaneously. The sensor exhibited hysteretic frequency behavior that depends on the orientation of the applied magnetic field relative to the direction of Love wave propagation. In the configuration in which the wave vector and the applied field form an angle of 45°, the resonant frequency seems to increase with the magnetization induced by the external field. When the wave vector propagation is parallel to the field, two positive peaks appear close to the coercive field of the film, which has not been reported before. This is probably due to a more complex relationship between the acoustic wave and the magnetic state of the film which could be exploited to give rise to new models of magnetic sensors.
Fe-based amorphous powder cores with low core loss and improvement of permeability
Authors: Nguyen Mai Phuong , Yoshida Shigeyoshi , Okamoto Satoshi , Miyazaki Takamichi , Endo Yasushi 
Published: February 2024

Fe-based amorphous powder cores of Fe–Si–B–Cr–C magnetic powder and phenolic binder were fabricated, and the effects of annealing and compaction pressure on the soft magnetic properties and core loss were investigated. The formation of Fe–B and α-Fe (Si) phases was confirmed at the annealing temperature above 773 K. The density gradually increased from 5.3 to 5.5 g/cm3 as annealing temperature increased, resulting in the saturation magnetization 4πMs increased to 1.0 T at 773 K. The effect of compaction pressure was studied by using samples annealed at 723 K. Both the density and 4πMs enhanced with compaction pressure from 980 to 1960 MPa. The real part of permeability µ’ remained constant for the frequency up to 2 MHz. The initial value of µ’ increased from 25 to 38 with compaction pressure. Consequently, at Bm of 50 mT and frequency of 100 kHz, the considerably low core loss of 67 kW/m3 was obtained. The low core loss and moderately high permeability of Fe–Si–B–Cr–C amorphous powder core across a wide frequency range indicate its potential for application in high frequency electronic components.
Ultrafast spin–orbit torque-induced magnetization switching in a 75°-canted magnetic tunnel junction
Authors: Nguyen T. V. A. , Naganuma H. , Honjo H. , Ikeda S. , Endoh T. 
Published: February 2024

We investigate the switching dynamics of a 75°-canted Spin–orbit torque (SOT) device with an in-plane easy axis using the micro-magnetic simulation. The switching time (τ) is evaluated from the time evolution of the magnetization. The device with a strong out-of-plane magnetic anisotropy (μ0Hkeff = −0.08 T) shows τ = 0.19 ns while a device with a strong in-plane magnetic anisotropy (μ0Hkeff = −0.9 T) shows τ = 0.32 ns. The increase of the damping constant (α) results in the increase of τ for both devices and the sub-nanosecond switching could be retained as α &lt; 0.14 in the device with μ0Hkeff = −0.08 T, while this was achieved as α &lt; 0.04 in the device with μ0Hkeff = −0.9 T. Furthermore when the field-like coefficient (β) is increased, it leads to a decrease in τ, which can be reduced to 0.03 ns by increasing β to 1 in the device with μ0Hkeff = −0.08 T. In order to achieve the same result in the device with μ0Hkeff = −0.9 T, β must be increased to 6. These results indicate a way to achieve ultrafast field-free SOT switching of a few tens of picoseconds in nanometer-sized magnetic tunnel junction (MTJ) devices.
Characteristics of blood flow velocity in the radial artery and finger capillaries using magnetoplethysmogram and photoplethysmogram
Authors: Lee Sang-Suk , Choi Rak-Gun , Kim Won-Tae , Shin Myung-Woo , Choi Jong-Gu , Hasan Mahbub , Jung Byungjo 
Published: February 2024

The Hall element and optical sensor, which can detect the magnetic field change caused by the minute fluctuations of the permanent magnet according to the periodic movement of the radial artery and the light absorption and reflection intensity according to the change in wrist blood flow, respectively, are used as key elements in digital healthcare devices. The pulse waves of the radial artery inside the wrist were measured and analyzed using a clip-type pulsimeter, magnetoplethysmogram (MPG). The pulse wave, which is the change in blood flow obtained by photoplethysmogram (PPG), was measured on the dorsal side of the wrist or the fingers simultaneously with MPG. The ABFV (artery blood flow velocity) is a few ten cm/s as DH (distance between MPG and PPG) divided by ΔT(a) which is the time difference between the first peaks of MPG and PPG waveforms on the dorsal side of the wrist. The PBFV (peripheral blood flow velocity) is a few mm/s as LH (hand length) divided by ΔT(p), which is the time difference between the first peak of MPG waveform and the third peak PPG waveform on the finger. For four subjects of 20s, SPWV was approximately 0.98∼1.19 m/s, ABFV in the radial artery was approximately 0.40∼0.44 m/s, and finger capillary PBFV was approximately 6.3∼8.6 cm/s. These results show reasonable values similar to the blood velocity of many blood vessels flowing through the human body.
Wet chemistry-synthesized Fe/mixed ferrite soft magnetic composites for high-frequency power conversion
Authors: Burgess Ward , Devkota Jagannath , Howard Bret 
Published: February 2024

State-of-the-art soft magnetic (SM) alloy systems such as electrical steels and permalloys exhibit large eddy current losses at high-frequency (kHz range and above), limiting their application in fast switching devices. Eddy current losses can be reduced for metallic alloys through a decrease in characteristic length scale or embedding them in an insulation layer. This work proposes the development of fine-scale core materials consisting of metallic SM nano/microparticles with magnetic, inorganic insulation layers, and their synthesis using a wet chemistry-based, scalable method for high frequency and high-power applications. More specifically, a magnetic ferrite coating (Ni0.5-xMnxZn0.5Fe2O4, x = 0.0–0.5) was applied via deposition of ferrite powder produced using a “wet chemistry-based” co-precipitation method; the ferrite was distributed through the Fe micropowder via either ball milling or ultrasonic mixing. Powder cores were prepared by compaction of the synthesized composites. Relative magnetic permeability and core loss were measured at excitation frequencies to 200 kHz. A core loss of 127 kW/m3 was measured at excitation frequency of 100 kHz and magnetization of 0.02 T. This value improves on the 199.3 kW/m3 reported in literature at identical excitation conditions for a compact formed from a composite comprising Fe microparticles coated with low-permeability Ni0.5Zn0.5Fe2O4. Ultrasonic mixing resulted in slightly lower core loss than ball milling, possibly because ball milling causes loss-increasing deformation of the Fe micropowder. XRD and SEM were used to observe composite composition and core cross-section microstructure.
Estimation of the Born data in inverse scattering of layered media
Authors: Jia Zekui , Li Maokun , Yang Fan , Xu Shenheng 
Published: February 2024

Abstract
The first term in the Born series, as we call the Born data, is linear with the scatterers. Here we present a scheme to map the total field data to the Born data in layered media using only the single-input single-output (SISO) setup. This nonlinear mapping is based on the reduced order model (ROM) approach, which constructs ROMs of the original wave operator. Normally, the construction of ROMs requires multi-input multi-output data. By introducing fictitious sensors, we estimate the Born data with SISO data in layered media. We give a simple way of using the time-domain Green’s function to estimate the received data for other fictitious sensors without calculating the complicated Sommerfeld integral. The resulting Born data contains only the single-scattering component, which can be helpful for many imaging applications. A numerical example is given incorporating the direct imaging back-propagation method. It validates the linearity of the Born data by providing an artifact-free image without the optimization process.
On the optimal planform of a cantilever unimorph piezoelectric vibrating energy harvester
Authors: Salman Eliya , Lustig Sahar , Elata David 
Published: February 2024

Abstract
This work relates to piezoelectric vibrating energy harvesters, that are constructed from a unimorph cantilever with a massive edge block. The dynamic response of the cantilever is considered when it is excited into vibrations at its natural frequency, where its deformation amplitude is maximal. The optimal response of such a harvester is achieved when the amplitude of the axial strain in the piezoelectric layer, is uniform. Practical technological considerations dictate the thickness of the unimorph, but its planform geometry (i.e. the vareation of the width along the cantilever) is a design choice. The optimal planform of such a unimorph cantilever has been the focus of many previous studies, which included extensive simulations and experimental investigations. In these previous studies it was concluded that the optimal planform is a trapeze, where the cantilever tapers from its clamped edge towards the edge block. However, to date, no model with explicit predictive capabilities was proposed. In the present study we derive an analytic expression of the planform, that ensures a uniform axial strain over the top surface of a cantilever unimorph with an edge block. Our analysis provides a rational explanation why a trapeze planform is optimal, and provides an explicit functional form of the optimal geometrical parameters of this planform. The predictive capabilities of our model are validated by comparison to finite element simulations.
An analysis of roadside particulate matter pollution and population exposure over the Pearl River Delta region of China under clear-sky condition using new ultra-high-resolution PM2.5 satellite-retrieval algorithms
Authors: Wu Y , Lee H F , Deng R R , Yim S H L 
Published: February 2024

Abstract
Roadside air pollution is one of the serious air pollution problems in urban areas. Even though roadside air pollution has been reported to cause adverse human health impacts, the spatial distribution of roadside air pollution in a large urban agglomeration has yet to be fully assessed. This study aimed to analyse roadside fine particulate matter (PM2.5) pollution and the population exposure in 11 cities in the Pearl River Delta (PRD) region of China. We developed satellite-retrieval algorithms with dark target method, vector support machine model and random forest model to retrieve the spatial distribution of PM2.5 at an ultra-high-spatial-resolution (30 m) based on 30 m Landsat-8 L1 data. Our results show that the retrieved PM2.5 had a promising consistency with PM2.5 measurements at general and roadside stations (R
2 = 0.86; RMSE = 7.72 µg m−3). Moreover, on average, the roadside PM2.5 in Dongguan, Foshan, and Guangzhou was relatively higher (up to 107.60 µg m−3) whereas that in Hong Kong was relatively lower (up to 30.40 µg m−3). The roadside PM2.5 pollution typically occurred in roads for motorized vehicles i.e. motorway, trunk, primary and secondary road. Our results also show that roadside PM2.5 was up to 17% higher in holidays than in workdays in all the PRD cities except Hong Kong that showed roadside PM2.5 higher in workdays than in holidays. The population-weighted PM2.5 decreased with increasing distances from roads in every PRD city, and population-weighted PM2.5 was estimated to be up to 22% higher at roadsides than at distances of 1500 m away from roads. This study pinpointed the seriousness of roadside air pollution in the PRD region.
Globalising innovation through co-inventions–the success case of the Korean lithium-ion battery industry
Authors: Peiseler Leopold , Jun Ye Lin , Schmid Nicolas , Waidelich Paul , Malhotra Abhishek , Schmidt Tobias S 
Published: February 2024

Abstract
Radical innovations can shift the global competitiveness of entire nations. While countries typically struggle to absorb knowledge about novel technologies quickly, in which knowledge tends to be spatially sticky, an important exception is the fast catch-up of the Korean Li-ion battery industry from Japan in the early 2000s. In this paper, we conduct an exploratory case study on this surprising success story. Focussing on patent co-inventions between Korea and Japan, we investigate their significance, as well as underlying types of co-inventions and types of transferred knowledge. To this end, we proceed in four steps: (1) a Poisson regression model; (2) social network analyses; (3) patent inventor tracking and (4) patent coding. Our results indicate that Korean–Japanese co-inventions hold significantly greater influence than other cross-country co-inventions, including with patents without cross-country collaboration. We find a pronounced knowledge-transfer intensity during the early 2000s and observe two types of co-inventions: organisation-level and inventor-level. Predominantly, we observe inventor-level co-inventions, i.e. Korean companies hiring experienced Japanese engineers, that proved important to transferring sticky knowledge. Moreover, while most patents target the design of core battery components, the share of manufacturing patents are—contrary to theoretical expectations—highest during the first half of the observation period. We also discuss our findings and draw implications for policy, industrial and academic players, including industry localisation policies, technology-inherent catch-up strategies and directions for future research.
Transfer operators on graphs: spectral clustering and beyond
Authors: Klus Stefan , Trower Maia 
Published: February 2024

Abstract
Graphs and networks play an important role in modeling and analyzing complex interconnected systems such as transportation networks, integrated circuits, power grids, citation graphs, and biological and artificial neural networks. Graph clustering algorithms can be used to detect groups of strongly connected vertices and to derive coarse-grained models. We define transfer operators such as the Koopman operator and the Perron–Frobenius operator on graphs, study their spectral properties, introduce Galerkin projections of these operators, and illustrate how reduced representations can be estimated from data. In particular, we show that spectral clustering of undirected graphs can be interpreted in terms of eigenfunctions of the Koopman operator and propose novel clustering algorithms for directed graphs based on generalized transfer operators. We demonstrate the efficacy of the resulting algorithms on several benchmark problems and provide different interpretations of clusters.
The impact of digital technology in care homes on unplanned secondary care usage and associated costs
Authors: Garner Alex , Lewis Jen , Dixon Simon , Preston Nancy , Caiado Camila C S , Hanratty Barbara , Jones Monica , Knight Jo , Mason Suzanne M 
Published: February 2024

Abstract

Background
A substantial number of Emergency Department (ED) attendances by care home residents are potentially avoidable. Health Call Digital Care Homes is an app-based technology that aims to streamline residents’ care by recording their observations such as vital parameters electronically. Observations are triaged by remote clinical staff. This study assessed the effectiveness of the Health Call technology to reduce unplanned secondary care usage and associated costs.

Methods
A retrospective analysis of health outcomes and economic impact based on an intervention. The study involved 118 care homes across the North East of UK from 2018 to 2021. Routinely collected NHS secondary care data from County Durham and Darlington NHS Foundation Trust was linked with data from the Health Call app. Three outcomes were modelled monthly using Generalised Linear Mixed Models: counts of emergency attendances, emergency admissions and length of stay of emergency admissions. A similar approach was taken for costs. The impact of Health Call was tested on each outcome using the models.

Findings
Data from 8,702 residents were used in the analysis. Results show Health Call reduces the number of emergency attendances by 11% [6–15%], emergency admissions by 25% [20–39%] and length of stay by 11% [3–18%] (with an additional month-by-month decrease of 28% [24–34%]). The cost analysis found a cost reduction of £57 per resident in 2018, increasing to £113 in 2021.

Interpretation
The introduction of a digital technology, such as Health Call, could significantly reduce contacts with and costs resulting from unplanned secondary care usage by care home residents.
Assessing the feasibility of a multimodal liquid biopsy for the diagnosis of HPV-associated oropharyngeal squamous cell carcinoma
Authors: Lewis James S , Naegele Saskia , Efthymiou Vasileios , Mehrad Mitra , Ely Kim A , Waterboer Tim , Lang Kuhs Krystle A , Davis Seth J , Richard Kelsey , Das Dipon , Faden Daniel L 
Published: February 2024

Abstract

Objectives
In this feasibility study, we explored the combined use of circulating tumor human papillomavirus (HPV) DNA (ctHPVDNA) and HPV serology as diagnostic tests for HPV-associated oropharyngeal squamous cell carcinoma (OPSCC).

Methods
Among patients with research-banked serum or plasma at diagnosis, IgG antibodies to oncoproteins from HPV types 16, 18, 31, 33, 35, 45, 52, and 58 were detected with multiplex serology. Positivity for HPV 16 was defined based on detection of combinations of anti-E6, E1, E2, and E7 and for other high-risk types on detection of anti-E6 and anti-E7. Circulating tumor HPV DNA was detected by custom digital droplet polymerase chain reaction (ddPCR) assays for HPV types 16, 18, 33, 35, and 45. p16 immunohistochemistry and high-risk HPV RNA in situ hybridization (ISH) using a cocktail of 18 high-risk HPV types were performed on tissue.

Results
Of 75 patients, 67 (89.3%) were HPV-associated (p16 and HPV RNA ISH positive) and 8 (10.7%) were HPV-independent. All 8 HPV-independent patients were seronegative and negative for ctHPVDNA (100% specificity). Serology was positive in 53 (79.1%) of 67 HPV-associated patients, while ddPCR was positive for ctHPVDNA in 59 (88.6%) of 67 HPV-associated patients. Requiring both tests to be positive resulted in a sensitivity of 50 (74.6%) of 67 while combining assays (either positive) improved sensitivity to 62 (92.6%) of 67.

Conclusions
Compared to HPV RNA ISH, HPV serology and ctHPVDNA are sensitive and highly specific biomarkers for HPV-associated OPSCC at the time of presentation.
Quantitative transcriptomic and epigenomic data analysis: a primer
Authors: Coussement Louis , Van Criekinge Wim , De Meyer Tim 
Published: February 2024

Abstract
Summary: The advent of microarray and second generation sequencing technology has revolutionized the field of molecular biology, allowing researchers to quantitatively assess transcriptomic and epigenomic features in a comprehensive and cost-efficient manner. Moreover, technical advancements have pushed the resolution of these sequencing techniques to the single cell level. As a result, the bottleneck of molecular biology research has shifted from the bench to the subsequent omics data analysis. Even though most methodologies share the same general strategy, state-of-the-art literature typically focuses on data type specific approaches and already assumes expert knowledge. Here, however, we aim at providing conceptual insight in the principles of genome-wide quantitative transcriptomic and epigenomic (including open chromatin assay) data analysis by describing a generic workflow. By starting from a general framework and its assumptions, the need for alternative or additional data-analytical solutions when working with specific data types becomes clear, and are hence introduced. Thus, we aim to enable readers with basic omics expertise to deepen their conceptual and statistical understanding of general strategies and pitfalls in omics data analysis and to facilitate subsequent progression to more specialized literature.
GeneGPT: augmenting large language models with domain tools for improved access to biomedical information
Authors: Jin Qiao , Yang Yifan , Chen Qingyu , Lu Zhiyong 
Published: February 2024

Abstract

Motivation
While large language models (LLMs) have been successfully applied to various tasks, they still face challenges with hallucinations. Augmenting LLMs with domain-specific tools such as database utilities can facilitate easier and more precise access to specialized knowledge. In this article, we present GeneGPT, a novel method for teaching LLMs to use the Web APIs of the National Center for Biotechnology Information (NCBI) for answering genomics questions. Specifically, we prompt Codex to solve the GeneTuring tests with NCBI Web APIs by in-context learning and an augmented decoding algorithm that can detect and execute API calls.

Results
Experimental results show that GeneGPT achieves state-of-the-art performance on eight tasks in the GeneTuring benchmark with an average score of 0.83, largely surpassing retrieval-augmented LLMs such as the new Bing (0.44), biomedical LLMs such as BioMedLM (0.08) and BioGPT (0.04), as well as GPT-3 (0.16) and ChatGPT (0.12). Our further analyses suggest that: First, API demonstrations have good cross-task generalizability and are more useful than documentations for in-context learning; second, GeneGPT can generalize to longer chains of API calls and answer multi-hop questions in GeneHop, a novel dataset introduced in this work; finally, different types of errors are enriched in different tasks, providing valuable insights for future improvements.

Availability and implementation
The GeneGPT code and data are publicly available at https://github.com/ncbi/GeneGPT.