bluuebunny/crossref_metadata_2025 huggingface dataset:
Recurrence of Resected Skull Base Meningiomas during Long-term Follow-up: Incidence and Predisposing Factors
Authors: Macarthur Joshua Ian , Hannan Cathal John , Howard Callum , Halliday Jane , Pathmanaban Omar Nathan , Hammerbeck-Ward Charlotte , Rutherford Scott A. , King Andrew T.
Published: April 2024

Introduction Skull base meningiomas (SBMs) are often subtotally resected and there is a paucity of evidence regarding the long-term rates of postoperative tumor progression. We aimed to investigate the factors that influence tumor recurrence in patients with an extended period of follow-up.

Methods Surgically resected tumors with long-term radiological follow-up were included for analysis. Data were collected on patient demographics, anatomical location, Simpson grade, World Health Organization (WHO) grade, modality of reintervention, and functional status. Recurrence was defined as tumor progression requiring intervention. Kaplan–Meier method and log-rank test were used to calculate recurrence-free probability. Cox regression analysis was used to determine factors associated with tumor progression.

Results Sixty-one patients were identified. Median radiological follow-up was 11.25 (IQR 4.3) years. Median age at first surgery was 50 (IQR 17) years. A total of 55/61(90%) tumors were WHO grade I and 6/61(10%) were grade II. Gross total resection (GTR) was achieved in 37/61 (60.7%) patients with subtotal resection (STR) in 24/61 (39.3%). In total, 28/61(45.9%) demonstrated recurrence/regrowth with a median time to recurrence of 2.8 (IQR 5) years. Also, 15/37 (40.5%) and 13/24 (54.2%) patients with GTR and STR, respectively, had tumor recurrence. Of the 28 recurrences, 4/28 (14.3%) underwent reresection, 9/28 (32.1%) were managed with radiotherapy, and 15/28 (53.6%) received both reresection and radiotherapy. Tumor grade was the only significant predictor of tumor recurrence (p = 0.033). Neurological function at last follow-up was significantly worse (modified Rankin scale >2) in patients with recurrence (p = 0.035).

Conclusion Surgically resected SBMs are associated with a significant recurrence rate during prolonged follow-up, irrespective of the extent of resection achieved. We recommend a prolonged period of radiological surveillance for SBM following surgical resection.
FreeGSNKE: A Python-based dynamic free-boundary toroidal plasma equilibrium solver
Authors: Amorisco N. C. , Agnello A. , Holt G. , Mars M. , Buchanan J. , Pamela S.
Published: April 2024

We present a Python-based numerical solver for the two-dimensional dynamic plasma equilibrium problem. We model the time evolution of toroidally symmetric free-boundary tokamak plasma equilibria in the presence of the non-linear magnetohydrodynamic coupling with both currents in the “active” poloidal field coils, with assigned applied voltages, and eddy currents in the tokamak passive structures. FreeGSNKE (FreeGS Newton–Krylov Evolutive) builds and expands on the framework provided by the Python package FreeGS (Free boundary Grad–Shafranov). FreeGS solves the static free-boundary Grad–Shafranov (GS) problem, discretized in space using finite differences, by means of Picard iterations. FreeGSNKE introduces: (i) a solver for the static free-boundary GS problem based on the Newton–Krylov (NK) method, with improved stability and convergence properties; (ii) a solver for the linearized dynamic plasma equilibrium problem; and (iii) a solver for the non-linear dynamic problem, based on the NK method. We propose a novel “staggered” solution strategy for the non-linear problem, in which we make use of a set of equivalent formulations of the non-linear dynamic problem we derive. The alternation of NK solution steps in the currents and in the plasma flux lends this strategy an increased resilience to co-linearity and stagnation problems, resulting in favorable convergence properties. FreeGSNKE can be used for any user-defined tokamak geometry and coil configuration. FreeGSNKE's flexibility and ease of use make it a suitably robust control-oriented simulator of plasma magnetic equilibria. FreeGSNKE is entirely written in Python and easily interfaced with Python libraries, which facilitates machine learning based approaches to plasma control.
Charge interaction behaviors at interfacial domains in DC GIL insulators
Authors: Pang Xi , Xie Zongliang , Xie Gengsheng , Liu Peng , Wang Qingyu , Peng Zongren , Li He
Published: April 2024

Long-term operation of high voltage direct current at elevated temperatures can result in the accumulation of surface charges in DC gas-insulated transmission line (GIL) insulators. Such a phenomenon leads to localized electric field distortion, increasing the risk of surface discharge. The analysis of interaction behaviors between surface charge and space charge at interfacial domains of GIL insulators is a complex task, which requires a comprehensive understanding of physical mechanisms of the gas–solid interface charging. In this work, a two-dimensional bipolar charge transport and interaction (2D BCTI) model is established, with the consideration of both surface and space charge dynamics. Pulsed electroacoustic tests and surface potential measurements are conducted on DC GIL insulator materials under different electrical-thermal coupling conditions. Experimental results exhibit great consistency with the predictions from the 2D BCTI model. The local accumulation of space charge near interfaces has certain effects on surface potential distribution, which in turn influences charge injection behavior from electrodes. In comparison to traditional surface charge simulation models, the consideration of space charge–surface charge interaction behaviors proves to be essential for estimating the polarity and amplitude of surface potential distribution. This model holds promise for assessing charge characteristics in electrical equipment where direct measurement is challenging.
Monte Carlo simulation of O2− ion transport and rate properties in noble gases with O2 addition
Authors: Ponomarev A. A. , Aleksandrov N. L.
Published: April 2024

The kinetics of O2− ions were numerically studied in He and Ar with a small admixture of O2 in a strong electric field through a Monte Carlo simulation. Cross sections for elastic scattering between O2− ions and He and Ar atoms were determined by adjusting cross section values to obtain good agreement between calculated and measured ion mobilities in pure helium and argon. Ion transport coefficients, mean energy, and detachment rate were calculated for various mole fractions of O2 and values of the reduced electric field. It was shown that the O2− ion mobility, mean energy, and detachment rate in He:O2 mixtures are much higher than those in Ar:O2 mixtures and air. A great difference between the properties of O2− ions in He–O2 and Ar–O2 mixtures was explained on the basis of the difference in the polarizability and mass for He and Ar atoms. Calculated detachment rates can be used for simulating guided ionization waves in He and Ar flows ejected into ambient air.
On the difficulty of determining Kármán “constants” from direct numerical simulations
Authors: Monkewitz Peter A.
Published: April 2024

The difficulty of determining the slope of the famed logarithmic law in the mean velocity profile of wall-bounded turbulent flows, the inverse of the Kármán “constant” κ, from direct numerical simulations (DNS) is discussed for channel flow. Unusual approaches as well as the analysis of the standard log-indicator function are considered and analyzed, including the identification of the higher order linear overlap term. This leads to the conclusion that a definitive determination of the channel flow κ from DNS with an uncertainty of, say, 2%–3% will require the residue of the mean streamwise momentum equation in the simulations to be reduced by at least an order of magnitude.
The effect of microsolvation on the structure, nuclear quadrupole coupling, and internal rotation: The methyl carbamate⋯(H2O)1–3 complexes
Authors: Pinacho Pablo , López Juan Carlos , Kisiel Zbigniew , Blanco Susana
Published: April 2024

Microsolvation of the carbamate moiety delivers precise information on complexation effects on the N–C=O backbone and is of relevance to the peptide bond functionality. In this context, the mono-, di-, and trihydrated complexes of methyl carbamate have been studied in molecular expansion by high-resolution microwave spectroscopy, using chirped-pulse and Fabry–Perot resonator Fourier transform microwave instruments covering the frequency range from 2 to 18 GHz. From the rotational constants of the parent and the 18Ow substituted monoisotopologues, accurate values have been derived for the geometries of the hydrogen bond interactions. The nuclear quadrupole coupling constant χcc of the nitrogen nucleus provides a direct measure of complexation changes and decreases with the degree of hydration, whereas the hindered internal rotation barrier increases slightly with microsolvation. Both tendencies could have a common origin in the π-cooperative inductive effects as the microsolvation series progresses. All transitions are split by the internal rotation of the methyl top and the nuclear quadrupole coupling, and in the largest cluster, they are additionally split by an inversion motion.
Deep learning-enhanced ghost imaging through dynamic and complex scattering media with supervised corrections of dynamic scaling factors
Authors: Peng Yang , Chen Wen
Published: April 2024

Ghost imaging (GI) through dynamic and complex scattering media remains challenging. The existence of dynamic scattering gives rise to a failure of GI schemes. Here, we report a deep learning-enhanced GI scheme with supervised corrections (SCGI) of dynamic scaling factors to realize high-resolution ghost reconstruction through dynamic and complex scattering media. The SCGI scheme is developed to approximate the variation of dynamic scaling factors in an optical channel and correct the recorded light intensities with a Gaussian prior. An untrained neural network powered by regularization by denoising for the SCGI scheme (SCGI-URED) is developed to further recover high-visibility ghost images. Experimental results demonstrate that high-resolution and high-visibility GI can be realized in dynamic and complex scattering media. The proposed method provides a reliable tool for implementing high-resolution and high-visibility GI through dynamic and complex scattering media and could give an impetus to developing dynamic scattering imaging in real-world scenarios.
The impact of US–China tensions on US science: Evidence from the NIH investigations
Authors: Jia Ruixue , Roberts Margaret E. , Wang Ye , Yang Eddie
Published: April 2024

Amid the discourse on foreign influence investigations in research, this study examines the impact of NIH-initiated investigations starting in 2018 on U.S. scientists’ productivity, focusing on those collaborating with Chinese peers. Using publication data from 2010 to 2021, we analyze over 113,000 scientists and find that investigations coincide with reduced productivity for those with China collaborations compared to those with other international collaborators, especially when accounting for publication impact. The decline is particularly pronounced in fields that received greater preinvestigation NIH funding and engaged more in U.S.–China collaborations. Indications of scientist migration and broader scientific progress implications also emerge. We also offer insights into the underlying mechanisms via qualitative interviews.
Voltage-induced calcium release in
Caenorhabditis elegans
body muscles
Authors: Gao Luna , Ardiel Evan , Nurrish Stephen , Kaplan Joshua M.
Published: April 2024

Type 1 voltage-activated calcium channels (CaV1) in the plasma membrane trigger calcium release from the sarcoplasmic reticulum (SR) by two mechanisms. In voltage-induced calcium release (VICR), CaV1 voltage sensing domains are directly coupled to ryanodine receptors (RYRs), an SR calcium channel. In calcium-induced calcium release (CICR), calcium ions flowing through activated CaV1 channels bind and activate RYR channels. VICR is thought to occur exclusively in vertebrate skeletal muscle while CICR occurs in all other muscles (including all invertebrate muscles). Here, we use calcium-activated SLO-2 potassium channels to analyze CaV1-SR coupling in
Caenorhabditis elegans
body muscles. SLO-2 channels were activated by both VICR and external calcium. VICR-mediated SLO-2 activation requires two SR calcium channels (RYRs and IP3 Receptors), JPH-1/Junctophilin, a PDZ (PSD95, Dlg1, ZO-1 domain) binding domain (PBD) at EGL-19/CaV1’s carboxy-terminus, and SHN-1/Shank (a scaffolding protein that binds EGL-19’s PBD). Thus, VICR occurs in invertebrate muscles.
Localizing somatic symptoms associated with childhood maltreatment
Authors: Dutcher Ethan G. , Verosky Sara C. , Mendes Wendy Berry , Mayer Stefanie E.
Published: April 2024

Childhood maltreatment has been linked to adult somatic symptoms, although this has rarely been examined in daily life. Furthermore, the localization of somatization associated with childhood maltreatment and its subtypes is unknown. This large-scale experience sampling study used body maps to examine the relationships between childhood maltreatment, its subtypes, and the intensity and location of negative somatic sensations in daily life. Participants (N = 2,234; 33% female and 67% male) were part of MyBPLab 2.0, a study conducted using a bespoke mobile phone application. Four categories of childhood maltreatment (emotional abuse, emotional neglect, physical abuse, and physical neglect) were measured using the Childhood Trauma Questionnaire. Using gender-matched human silhouettes, participants indicated the location and intensity of feelings of negative activation in the body. Childhood maltreatment generally and its four measured subtypes were all positively associated with heightened negative activation on both the front and back body maps. For females, total childhood maltreatment was associated with negative activation in the abdomen and lower back, while for males, the association was localized to the lower back. Similarly, each of the four subscales had localized associations with negative activation in the abdomen and lower back in females and lower back in males, except for emotional abuse, which was also associated with negative activation in the abdomen in males. These associations likely reflect increased somatization in individuals exposed to childhood maltreatment, suggesting a role for psychotherapeutic interventions in alleviating associated distress.
An essential and highly selective protein import pathway encoded by nucleus-forming phage
Authors: Morgan Chase J. , Enustun Eray , Armbruster Emily G. , Birkholz Erica A. , Prichard Amy , Forman Taylor , Aindow Ann , Wannasrichan Wichanan , Peters Sela , Inlow Koe , Shepherd Isabelle L. , Razavilar Alma , Chaikeeratisak Vorrapon , Adler Benjamin A. , Cress Brady F. , Doudna Jennifer A. , Pogliano Kit , Villa Elizabeth , Corbett Kevin D. , Pogliano Joe
Published: April 2024

Targeting proteins to specific subcellular destinations is essential in prokaryotes, eukaryotes, and the viruses that infect them. Chimalliviridae phages encapsulate their genomes in a nucleus-like replication compartment composed of the protein chimallin (ChmA) that excludes ribosomes and decouples transcription from translation. These phages selectively partition proteins between the phage nucleus and the bacterial cytoplasm. Currently, the genes and signals that govern selective protein import into the phage nucleus are unknown. Here, we identify two components of this protein import pathway: a species-specific surface-exposed region of a phage intranuclear protein required for nuclear entry and a conserved protein, PicA (Protein importer of chimalliviruses A), that facilitates cargo protein trafficking across the phage nuclear shell. We also identify a defective cargo protein that is targeted to PicA on the nuclear periphery but fails to enter the nucleus, providing insight into the mechanism of nuclear protein trafficking. Using CRISPRi-ART protein expression knockdown of PicA, we show that PicA is essential early in the chimallivirus replication cycle. Together, our results allow us to propose a multistep model for the Protein Import Chimallivirus pathway, where proteins are targeted to PicA by amino acids on their surface and then licensed by PicA for nuclear entry. The divergence in the selectivity of this pathway between closely related chimalliviruses implicates its role as a key player in the evolutionary arms race between competing phages and their hosts.
Structural insights into human MHC-II association with invariant chain
Authors: Wang Nan , Waghray Deepa , Caveney Nathanael A. , Jude Kevin M. , Garcia K. Christopher
Published: April 2024

The loading of processed peptides on to major histocompatibility complex II (MHC-II) molecules for recognition by T cells is vital to cell-mediated adaptive immunity. As part of this process, MHC-II associates with the invariant chain (Ii) during biosynthesis in the endoplasmic reticulum to prevent premature peptide loading and to serve as a scaffold for subsequent proteolytic processing into MHC-II-CLIP. Cryo–electron microscopy structures of full-length Human Leukocyte Antigen-DR (HLA-DR) and HLA-DQ complexes associated with Ii, resolved at 3.0 to 3.1 Å, elucidate the trimeric assembly of the HLA/Ii complex and define atomic-level interactions between HLA, Ii transmembrane domains, loop domains, and class II-associated invariant chain peptides (CLIP). Together with previous structures of MHC-II peptide loading intermediates DO and DM, our findings complete the structural path governing class II antigen presentation.
Towards a competition-based word-formation theory
Authors: Nagano Akiko , Bagasheva Alexandra , Renner Vincent
Published: April 2024

This chapter provides an overview of the study of
competition in word-formation theories, drawing on the findings of the ten
chapters collected in this volume and other recent contributions. It
explores recurrent issues regarding (i) the triggers and outcomes of
competition, (ii) the variety of competing forms, and (iii) the synonymy
condition for competition. With respect to the first set of research
questions, a binary typology of form-based and meaning-based resolutions is
identified, with each pole providing multiple ways to resolve competition.
Next, for the form-related research questions, the distinction between
macro‑ and micro-level competition is significant. Finally, the synonymy
condition is reassessed through a careful comparison between morphologically
simplex and complex lexemes, leading to a definition of competing rivals in
word-formation as a set of formally suppletive morphological processes that
produce propositional, near, or sense synonyms.
[N1 + N2], [N + A], and [N1 + de + N2]
Authors: Koga Kentaro
Published: April 2024

[N1 + N2], [N1 + A], and [N1 + P + N2]
constructions have a function of naming subcategories of the concept
indicated by the N1. [N1 + A] and [N1 + P + N2] constructions are
considered as lexicalized syntactic units, whereas [N1 + N2]
constructions cannot be formed by syntactic rules. The formation of
[N1 + N2] constructions is based on a model created by an analogy
from existent binominal constructions. The three types of
constructions under investigation can establish a tripartite
competition, but such cases do not always occur, because of the
conditional productivity of [N1 + N2], the lack of adjectival form
and restrictions on the formation of [N1 + de +
N2].
Revisiting Poser’s (1992) “Blocking of phrasal constructions by
lexical items” from the perspective of the economy of language use
principle
Authors: Yuhara Ichiro
Published: April 2024

Poser
(1992) is an important paper that points out that
blocking applies not only to synonyms but also to synonymous
phrases, using Japanese examples. This chapter aims to update his
discussion and proposal using Ueno’s (2014) “economy of language use” principle
requiring to choose a structurally simpler expression when there are
two semantically rivaling expressions. Considering the significance
of two semantically similar but formally non-identical
representations co-existing redundantly, this chapter also puts
forth Sadock’s (2012)
multi-modular grammar as a model that embodies the idea that grammar
is competition.
Performance enhancement of Ge/Si avalanche photodetector by specific sidewall passivation using remote oxygen plasma treatment
Authors: Huang Donglin , Ji Ruoyun , Yao Liqiang , Jiao Jinlong , Li Cheng , Lin Guangyang , Huang Wei , Li Xin , Chen Songyan
Published: April 2024

We report an obvious improvement in the performance of a separated absorption charger-layer multiplication Ge/Si avalanche photodetector, achieved by passivating the sidewalls with a low-temperature remote oxygen plasma (ROP) treatment. The dangling bonds on the Ge surface can be efficiently passivated by the formation of an ideal Ge/GeO2 interface. With ROP passivation, the leakage current of the device shows a three- to fourfold decrease at 300 K, resulting in a dark current (I
dark) of 3.5 × 10−6 A at 90% avalanche voltage (V
br) and 3.4 × 10−7 A at punch-through voltage (V
puhch-through) for the 26 μm-diameter device. A reduction of over tenfold is demonstrated at 200 K and the passivation mechanism is revealed. In addition, a multiplication gain of 94 is obtained under 1550 nm illumination. The device with ROP passivation shows an improved gain bandwidth product of 190 GHz. The enhanced high-frequency response of the device with ROP passivation can be attributed to the alleviation of the retarding effect caused by the interface state on the sidewalls. Without using a trans-impedance amplifier, an opening eye diagram at 28 Gbps is demonstrated, indicating reliable device transmission performance.
Magneto-optical detection of non-collinear magnetization states in ferromagnetic multilayers
Authors: Martín Valderrama Carmen , Prieto Irene , Quintana Mikel , Berger Andreas
Published: April 2024

We have experimentally studied the relationship in between non-collinear magnetization states in ferromagnetic (FM) multilayers and their resulting magneto-optical (MO) properties. Hereby, we observe that the phase of the complex-valued MO parameters are especially sensitive towards non-collinear magnetization states and enable their unambiguous detection. For the purpose of our experimental study, we designed, fabricated and characterized a set of epitaxial FM/NM/FM multilayers with in-plane uniaxial anisotropy, in which the non-magnetic (NM) interlayer thickness t was varied, so that tunable FM interlayer exchange coupling strength in between the two FM layers could be achieved. Furthermore, the two FM layers were made from different alloys, so that they exhibit different levels of magnetocrystalline anisotropy, which enables a collinear to non-collinear magnetization state transition upon applying a magnetic field

H

away from the in-plane easy axis for samples with sufficiently large

t

. Utilizing generalized MO ellipsometry, we determined the full reflection matrix
R
as a function of

H

and we observed that the phases of the complex-valued MO coefficients in
R
change with

H

in multilayers that have sufficiently weak interlayer coupling strength, i.e. large t, which can only happen if non-collinear magnetization states of varying non-collinearity occur in those samples. For samples with small t, corresponding to strongly exchange coupled FM layers, this effect is absent, consistent with the existence of collinear magnetization states in those multilayers for all

H

values.
Effect of growth conditions on magnetization reversal and magnetic anisotropy in Co2Fe0.5Ti0.5Si quaternary Heusler alloy thin films
Authors: Rahaman Mainur , Longchar Lanuakum A , Lalita  , Basheed G A , Reddy V Raghavendra , Raja M Manivel , Kaul S N , Srinath S
Published: April 2024

Ferromagnetic resonance and magneto-optic Kerr effect (MOKE) techniques are employed to unravel the nature of ‘in-plane’ (IP) magnetic anisotropy and magnetization reversal (MR) processes in magnetron-sputtered 100 nm Co2Fe0.5Ti0.5Si (CFTS) thin films, deposited (and subsequently annealed) at different substrate temperatures (Ts) ranging from 200 °C to 550 °C. By varying TS, the CFTS films are produced with different amounts of anti-site (AS) atomic disorder. Irrespective of the degree of AS disorder, the IP uniaxial magnetic anisotropy (UMA) is prevalent in all the CFTS films. The TS450 and TS500 films, deposited at T
S = 450 °C and 500 °C, stand out as they have (i) the least AS disorder, (ii) lowest value (α = 0.0055) of the Gilbert damping constant, (iii) high saturation magnetization (

≅
770

 

G

) at 300 K, (iv) UMA energy density as high as

≅
1.6
×

10
4

erg

/

c
c

at 120 K dropping to

≅
1.0
×

10
4

erg

/

c
c

at 300 K, (v) spin-wave stiffness (

D

) at T = 0 K,

D
0

≅
175

 meV

Å

2

and, as in other CFTS films, the electron–magnon interaction is primarily responsible for the thermal renormalization of

D

. Furthermore, in the TS450 and TS500 films, MOKE hysteresis loops at various angles (

ψ
H

) that the field makes with the easy axis in the film plane, reveals two mutually exclusive UMAs,

U
M

A
1

≫
U
M

A
2

, with easy axes perpendicular to each other. By contrast, only a single UMA is observed in all the remaining films. When

ψ
H

=

0
∘

, MOKE domain images reveal that, consistent with the uniaxial nature of magnetic anisotropy, an abrupt reversal of magnetization is accompanied by the formation of 180° domains. When

ψ
H

= 90°, due to the presence of two UMAs in TS450 and TS500 films, following the field reversal, first the reverse domains nucleate and then grow at the expense of the fundamental domains through field-induced domain wall motion.
Enhancing selective production of atomic oxygen through nanosecond pulse-burst driven mode in a He/O2 dielectric barrier discharge
Authors: Wang Da-Zhi , Qiao Jun-Jie , Yang Qi , Sun Fu-Li , Xiong Qing
Published: April 2024

In this study, the temporal evolution of O atoms in a nanosecond burst-pulsed dielectric barrier discharge (DBD) is measured by two-photon absorption laser-induced fluorescence spectroscopy. The experiment is conducted at burst conditions of 50, 100, and 200 kHz pulse frequency, 10 Hz burst frequency, and 20–400 pulses in 0.1%–2% O2 + He mixtures. The accumulation effect of O atoms in the burst mode is observed and the density gradually saturates at around 100 pulses. Increasing the pulse frequency effectively enhances the O saturation density. The 0-dimensional kinetic model reveals that the saturation effect is primarily balanced by the formation and loss characteristics of O atoms. Similar saturation effect is also observed in the typical continuous periodic pulse mode (one pulse each cycle), but with a saturation density about one order of magnitude lower than that in the burst case, highlighting the burst excitation mode as an effective method for enhancing the instantaneous peak production of O atoms. Further investigations into the influence of O2 proportion on the selective production of O atoms are also performed. The results suggest that a low O2 proportion (<2%) and pulse-burst driven mode for the He/O2 DBD facilitates the selective production of O atoms while competing with O3 formation.
Adaptive impedance matching in microwave and terahertz metamaterial absorbers using PIN diodes and GaN HEMTs
Authors: Liu Yunpeng , Ibrahim Suriani , Majid Nazia Abdul , Mohd Sabri Mohd Faizul , Sun Jianwen , Zhuo Qiming , Liu Wei
Published: April 2024

Metamaterial absorbers allow electromagnetic waves to be converted into heat energy based on impedance matching. However, passive metamaterial absorbers exhibit fixed absorption characteristics, limiting their flexibility. This work demonstrates tunable microwave and terahertz absorbers by integrating adjustable resistors into the metamaterial units. First, a microwave absorber from 1 to 5 GHz was designed by embedding PIN diodes with voltage-controlled resistance. Calculations, simulations, and measurements verified two separate absorption peaks over 90% when optimized to a resistance of 250 Ω. The absorption frequencies shifted based on the resistor tuning. Building on this, a terahertz absorber was modeled by substituting gallium nitride high electron mobility transistors (GaN HEMTs) as the adjustable resistor component. The GaN HEMTs were controlled by an integrated gate electrode to modify the two-dimensional electron gas density, allowing resistance changes without external voltage terminals. Simulations revealed two absorption peaks exceeding 90% absorption at 0.34 THz and 1.06 THz by adjusting the equivalent resistance from 180 Ω to 380 Ω, and the tunable resistance is verified by DC measurement of single GaN HEMT in the unit. This work demonstrates how integrating adjustable resistors enables dynamic control over the absorption frequencies and bandwidths of metamaterial absorbers. The proposed geometries provide blueprints for tunable microwave and terahertz absorbers.
Thermal transport in fullerene-based molecular junctions: molecular dynamics simulations
Authors: Li Joanna , Wang Jonathan J , Segal Dvira
Published: April 2024

We investigate phonon thermal transport of fullerene-based single-molecule junctions by employing classical molecular dynamics (MD) simulations. We compute the thermal conductances of C60 fullerene monomers, dimers, and trimers utilizing three distinct MD methods. We observe the equilibration dynamics in one approach, and employ two other nonequilibrium steady state simulation methods. We discuss technical aspects of each simulation technique, and show that their predictions for the thermal conductance agree. Our simulations reveal that while the thermal conductance of fullerene monomer and dimer junctions remains similar, that of trimer junctions experiences a significant reduction. This study could assist in the design of high-performing thermoelectric junctions, where low thermal conductance is desired.
Integrity monitoring for decentralized redundant IMUs/GNSS integrated navigation system with correlated measurements
Authors: Yang Shaohua , Zhang Xiaodong , Li Ao , Zhang Xun , Xu Bin
Published: April 2024

In civil aviation systems, the inertial measurement unit (IMU)/Global Navigation Satellite System (GNSS) integrated navigation remains the most effective navigation scheme. Based upon this, the utilization of redundant IMUs and a multi-constellation system can significantly enhance navigation and integrity performance. However, redundant IMUs/GNSS integrated navigation systems are susceptible to more complex failure modes, including GNSS faults (satellite and constellation faults) and IMU faults. Additionally, dealing with correlated measurements between redundant constructions presents a challenging issue. Therefore, we propose an integrity monitoring method for decentralized redundant IMUs/GNSS integrated navigation systems. This method considers GNSS faults and IMU fault in the integrity monitoring process, specifically designed for decentralized filter construction with redundancy. Furthermore, due to the correlated measurements between redundant filters, optimal fusion coefficients are determined by considering the unbiased estimate and minimizing the trace covariance of the primary filter. An optimal allocation scheme for continuity risk is also established to improve navigation and integrity performance. Simulation results demonstrate the feasibility and effectiveness of the proposed integrity monitoring method. Moreover, in the context of correlated measurements, the integrated navigation system also exhibits superiority.
Dual-range TMR current sensor based on magnetic shunt/aggregation effects utilizing single magnetic ring structure
Authors: Bai Ru , Li Boyan , Tu Jiakun , Yang Tengda , Dou Aiyu , Sun Yucheng , Qian Zhenghong
Published: April 2024

In this paper, we propose and design a novel dual-range tunnel magnetoresistance (TMR) current sensor with a single magnetic ring structure. This design incorporates two distinct magnetic guiding effects, namely magnetic shunt and magnetic aggregation, within the same magnetic ring. By integrating a high-sensitivity TMR sensor chip with a closed-loop feedback circuit, we achieve a TMR current sensor with excellent linearity, high resolution, as well as high frequency response. The magnetic ring structure is first modeled and simulated, establishing a correlation between the distribution of magnetic induction intensity and the parameters of the magnetic ring and feedback coils. Through simulation optimization and theoretical calculations, we determine the optimal positions for TMR sensor chips in the magnetic ring, suitable for both current ranges. When a signal current is present, the TMR sensor chip generates a weak differential voltage signal, which is subsequently amplified, processed, and automatically transmitted to the laptop via a serial port. Furthermore, the sensor allows for automatic switching between the two current ranges. The results demonstrate that our designed dual-range current sensor exhibits outstanding performance characteristics, including a high resolution of 500 μA in the small range, accuracy of 0.10%, excellent linearity of 0.011%, and a fast frequency response of 500 kHz. These features make it highly applicable in various fields such as new energy vehicles and smart grids, indicating promising prospects for its widespread utilization.
Polydopamine-mediated immobilization of BMP-2 onto electrospun nanofibers enhances bone regeneration
Authors: Chen Zhuo , Li Jing , Wang Zichen , Chen Yuehui , Jin Mingchao , Chen Shuo , Xie Jinlu , Ge Shuhui , He Hongyi , Xu Juntao , Wu Fengfeng
Published: April 2024

Dealing with bone defects is a significant challenge to global health. Electrospinning in bone tissue engineering has emerged as a solution to this problem. In this study, we designed a PVDF-b-PTFE block copolymer by incorporating TFE, which induced a phase shift in PVDF from α to β, thereby enhancing the piezoelectric effect. Utilizing the electrospinning process, we not only converted the material into a film with a significant surface area and high porosity but also intensified the piezoelectric effect. Then we used polydopamine to immobilize BMP-2 onto PVDF-b-PTFE electrospun nanofibrous membranes, achieving a controlled release of BMP-2. The scaffold’s characters were examined using SEM and XRD. To assess its osteogenic effects in vitro, we monitored the proliferation of MC3T3-E1 cells on the fibers, conducted ARS staining, and measured the expression of osteogenic genes. In vivo, bone regeneration effects were analyzed through micro-CT scanning and HE staining. ELISA assays confirmed that the sustained release of BMP-2 can be maintained for at least 28 d. SEM images and CCK-8 results demonstrated enhanced cell viability and improved adhesion in the experimental group. Furthermore, the experimental group exhibited more calcium nodules and higher expression levels of osteogenic genes, including COL-I, OCN, and RUNX2. HE staining and micro-CT scans revealed enhanced bone tissue regeneration in the defective area of the PDB group. Through extensive experimentation, we evaluated the scaffold’s effectiveness in augmenting osteoblast proliferation and differentiation. This study emphasized the potential of piezoelectric PVDF-b-PTFE nanofibrous membranes with controlled BMP-2 release as a promising approach for bone tissue engineering, providing a viable solution for addressing bone defects.
Formation of Si nanopillars through partial sacrificing in super passivation reactive ion etching
Authors: Zhang Jingjing , Yu Lihui , Ye Shujun , Zhao Qiutong , Guo Jingquan , Yin Hongxing , Wang Yeliang
Published: April 2024

The vertical gate-all-around (VGAA) metal-oxide-semiconductor field-effect transistor (MOSFET) holds remarkable potential in the three-dimensional (3D) integrated circuits (ICs), primarily owing to its capacity for vertical integration. The Si nanopillar, a crucial channel in the VGAA MOSFET, is conventionally shaped via the reactive ion etching (RIE) system employing SF6/O2. Past studies have indicated that high O2 gas conditions in RIE often result in Si grasses irregular nanostructures, such as nanospikes on the bottom surface, due to over-passivation. However, this study revealed that ultrahigh O2 proportions (>70%), especially when combined with low chamber pressure, inhibit the development of Si grasses in the RIE system (termed as super passivation). Nevertheless, this scenario leads to the segmentation of the Si nanopillar. To address this issue, a proposed partial sacrificing method, achieved by sacrificing the upper segment of the nanopillar through prolonged processing time and reduced mask size, successfully yielded Si nanopillars without Si grasses. Furthermore, an empirical model was developed to elucidate how experimental parameters influence etching characteristics, encompassing etching rate and Si nanopillar shape, through a systematic examination of the RIE etching process. This research significantly contributes to the production of VGAA MOSFETs and 3D ICs.
Oxidation behavior and atomic structural transition of size-selected coalescence-resistant tantalum nanoclusters
Authors: Hu Shengyong , Hu Kuojuei , Zhang Yongxin , Shah Syed Adil , Zhao Zixiang , Zuo Zewen , Lu Siqi , Tang Sichen , Zhu Wuwen , Fang Liu , Song Fengqi
Published: April 2024

Herein a series of size-selected Ta
N
(N = 147, 309, 561, 923, 1415, 2057, 6525, 10 000, 20 000) clusters are generated using a gas-phase condensation cluster beam source equipped with a lateral time-of-flight mass-selector. Aberration-corrected scanning transmission electron microscopy (AC-STEM) imaging reveals good thermal stability of Ta
N
clusters in this study. The oxidation-induced amorphization is observed from AC-STEM imaging and further demonstrated through x-ray photoelectron spectroscopy and energy-dispersive spectroscopy. The oxidized Ta predominantly exists in the +5 oxidation state and the maximum spontaneous oxidation depth of the Ta cluster is observed to be 5 nm under prolonged atmosphere exposure. Furthermore, the size-dependent sintering and crystallization processes of oxidized Ta
N
clusters are observed with an in situ heating technique, and eventually, ordered structures are restored. As the temperature reaches 1300 °C, a fraction of oxidized Ta309 clusters exhibit decahedral and icosahedral structures. However, the five-fold symmetry structures are absent in larger clusters, instead, these clusters exhibit ordered structures resembling those of the crystalline Ta2O5 films. Notably, the sintering and crystallization process occurs at temperatures significantly lower than the melting point of Ta and Ta2O5, and the ordered structures resulting from annealing remain well-preserved after six months of exposure to ambient conditions.
Thermometry mapping during CT-guided thermal ablations: proof of feasibility and internal validation using spectral CT
Authors: Zhang Kuan , Ferrero Andrea , In Myung-Ho , Favazza Christopher P
Published: April 2024

Objective. Conventional computed tomography (CT) imaging does not provide quantitative information on local thermal changes during percutaneous ablative therapy of cancerous and benign tumors, aside from few qualitative, visual cues. In this study, we have investigated changes in CT signal across a wide range of temperatures and two physical phases for two different tissue mimicking materials, each. Approach. A series of experiments were conducted using an anthropomorphic phantom filled with water-based gel and olive oil, respectively. Multiple, clinically used ablation devices were applied to locally cool or heat the phantom material and were arranged in a configuration that produced thermal changes in regions with inconsequential amounts of metal artifact. Eight fiber optic thermal sensors were positioned in the region absent of metal artifact and were used to record local temperatures throughout the experiments. A spectral CT scanner was used to periodically acquire and generate electron density weighted images. Average electron density weighted values in 1 mm3 volumes of interest near the temperature sensors were computed and these data were then used to calculate thermal volumetric expansion coefficients for each material and phase. Main results. The experimentally determined expansion coefficients well-matched existing published values and variations with temperature—maximally differing by 5% of the known value. As a proof of concept, a CT-generated temperature map was produced during a heating time point of the water-based gel phantom, demonstrating the capability to map changes in electron density weighted signal to temperature. Significance. This study has demonstrated that spectral CT can be used to estimate local temperature changes for different materials and phases across temperature ranges produced by thermal ablations.
Time delays between physiological signals in interpreting the body’s responses to intermittent hypoxia in obstructive sleep apnea
Authors: Li Geng , Zhou Mengwei , Huang Xiaoqing , Ji Changjin , Fan Tingting , Xu Jinkun , Xiong Huahui , Huang Yaqi
Published: April 2024

Objective. Intermittent hypoxia, the primary pathology of obstructive sleep apnea (OSA), causes cardiovascular responses resulting in changes in hemodynamic parameters such as stroke volume (SV), blood pressure (BP), and heart rate (HR). However, previous studies have produced very different conclusions, such as suggesting that SV increases or decreases during apnea. A key reason for drawing contrary conclusions from similar measurements may be due to ignoring the time delay in acquiring response signals. By analyzing the signals collected during hypoxia, we aim to establish criteria for determining the delay time between the onset of apnea and the onset of physiological parameter response. Approach. We monitored oxygen saturation (SpO2), transcutaneous oxygen pressure (TcPO2), and hemodynamic parameters SV, HR, and BP, during sleep in 66 patients with different OSA severity to observe body’s response to hypoxia and determine the delay time of above parameters. Data were analyzed using the Kruskal–Wallis test, Quade test, and Spearman test. Main results. We found that simultaneous acquisition of various parameters inevitably involved varying degrees of response delay (7.12–25.60 s). The delay time of hemodynamic parameters was significantly shorter than that of SpO2 and TcPO2 (p< 0.01). OSA severity affected the response delay of SpO2, TcPO2, SV, mean BP, and HR (p < 0.05). SV delay time was negatively correlated with the apnea-hypopnea index (r = −0.4831, p< 0.0001). Significance. The real body response should be determined after removing the effect of delay time, which is the key to solve the problem of drawing contradictory conclusions from similar studies. The methods and important findings presented in this study provide key information for revealing the true response of the cardiovascular system during hypoxia, indicating the importance of proper signal analysis for correctly interpreting the cardiovascular hemodynamic response phenomena and exploring their physiological and pathophysiological mechanisms.
The Advanced Computing Hub at BSC: improving fusion codes following modern software engineering standards
Authors: Sáez X , Soba A , Ylla Català J V , Saxena G , Garcia-Gasulla M , Morales C , Dorca D V , Komm M , Podolnik A , Romazanov J , Sánchez E , Velasco J L , Mantsinen M J
Published: April 2024

Several dedicated High-Performance Computing (HPC) centers provide essential expertise and support in developing a suitable portfolio of EUROfusion standard codes. Barcelona Supercomputing Center (BSC) is one of these HPC hubs involved in this complex task. Several fusion codes were selected, installed and analyzed to meet the developers’ requirements, ranging from portability to GPU, improving the performance, getting better data management, extending the capacity of coupling with other codes, etc. In this paper, we will describe the work developed by BSC and some of the tasks carried out in this project. We will explain briefly how the project is faced and the work required to create good quality codes, i.e. robust and trustable software capable of running efficiently in modern HPC systems.
Radial basis function neural network for solution of two-dimensional burgers’ equation
Authors: Kapoor Mamta , Rawal Kirti
Published: April 2024

In present research a neural network-based method named as ‘Radial basis function neural network method’ is tested upon two-dimensional Burgers’ equation. For this purpose, five types of the radial basis functions are considered such as; Linear, Cubic, Quintic, Multiquadric, and gaussian. The validation of results is provided via

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error, Mean Square Error, and the Root Mean Square Error. The obtained errors are acceptable from mathematical view point. The graphical compatibility of the results is also tested via the comparison of exact and predicted solutions in the graphs. It is a novel viewpoint to tackle the complex natured mathematical problems. In such method there is no discretization, linearization or quasi-linearization is provided. Therefore, no such scope of error is present. The present method will surely be a major breakthrough to tackle numerous mathematical models.
Improved electrical properties in PZT/PZ thin films by adjusting annealing temperature
Authors: Yang F , Chen J Y , Hou M Z , Cao Y F , Zhang Y , Li X F , Zhang X Q , Hu Y C , Shang J , Yin S Q , Wang X W
Published: April 2024

In this study, PbZr0.52Ti0.48O3/PbZrO3 (PZT/PZ) multilayer films were prepared on SiO2/Si substrate buffered with LaNiO3 (LNO) thin films, and then annealed at different temperatures by rapid thermal annealing (RTA) technology. The phase structures, microstructures, and electrical properties of the obtained PZT/PZ multilayer films were studied. According to the results of XRD and SEM, it was found that the PZ films with perovskite phase were obtained by annealing at 650 °C firstly. The PZT films on crystallized PZ films were in amorphous phase after annealing at 450 °C, in pyrochlore phase after annealing at 550 °C, and finally in perovskite phase at annealing temperature higher than 600 °C. The multilayer films with the PZT films annealed at 550 °C exhibited linear hysteresis loops, and such films showed the enhanced energy storage density of 31.6 J cm−3 and the energy storage efficiency of 66.9% at a high breakdown field strength of 2475 kV cm−1. The experimental results proved that the phase structure of the PZT/PZ multilayer films can be regulated by different annealing temperatures, which could further enhance the energy storage performance of the PZT/PZ multilayer films.
A space dependent Cosmological Constant
Authors: Comelli D.
Published: April 2024

In a specific adiabatic perfect fluid, intrinsic entropy density perturbations are the
source of a space-dependent cosmological constant responsible for local void inhomogeneity.
Assuming an anisotropic Locally Rotationally Symmetric space time, using the 1+1+2 covariant
approach and a Lemaître space time metric, we study the cosmological implication of
such a scenario giving a proper solution to the Hubble constant tension and providing, locally,
also an effective equation of state with w ≤ -1.