bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular simulations and hydrodynamic theory of nonlocal shear-stress correlations in supercooled fluids
Authors: Steffen David , Schneider Ludwig , Müller Marcus , Rottler Jörg
Published: July 2022

A supercooled fluid close to the glass transition develops nonlocal shear-stress correlations that anticipate the emergence of elasticity. We performed molecular dynamics simulations of a binary Lennard-Jones mixture at different temperatures and investigated the spatiotemporal autocorrelation function of the shear stress for different wavevectors, q, from a locally measured and Fourier-transformed stress tensor. Anisotropic correlations are observed at non-zero wavevectors, exhibiting strongly damped oscillations with a characteristic frequency ω(q). A comparison with a recently developed hydrodynamic theory [Maier et al., Phys. Rev. Lett. 119, 265701 (2017)] shows a remarkably good quantitative agreement between particle-based simulations and theoretical predictions.
A terahertz signal enhancement implemented by subwavelength metallic grooves
Authors: Ren Yinghui , Wang Xiaogang , Xiao Chijie
Published: July 2022

This research analyzes the field enhancement properties of a subwavelength metallic groove working at 0.4 terahertz (THz), which is potentially applicable as a receiver to enhance THz signals in integrated circuits. We derive the analytic formulation of the field magnification by utilizing the distinctive characteristics of the electromagnetic (EM) field inside and above the groove with the EM field continuity on the upper and lower surfaces of the groove. This method, known as the Bruijn theory, has been applied in acoustics and optics to obtain reflection and absorption coefficients. Then, the dependence of these field enhancement properties on both the groove width and depth is examined by theoretical analysis and numerical simulations consistently. Results show that the field enhancement varies periodically with the groove depth in a period of 0.5λ, featuring the typical Fabry–Perot resonance. The field enhancement is inversely proportional to the groove width due to the cavity effect. Besides, the field intensity can be further enhanced by 10% via appropriately rounding the sharp vertices at the inlet of the groove. Moreover, the incident angle effect on the field enhancing property is explored. An enhancement of >32 dB can be realized at any incident angle with a groove of dimensions 158×225μm2. These results are helpful for understanding the field enhancement mechanism and designing novel THz plasmonic devices, such as an easily manufactured antenna receiver or sensor with simple and compact configuration, as well as offering a feasible solution for the high attenuation problem of THz communications.
Efficient evaluation of the Breit operator in the Pauli spinor basis
Authors: Sun Shichao , Ehrman Jordan , Sun Qiming , Li Xiaosong
Published: July 2022

The frequency-independent Coulomb–Breit operator gives rise to the most accurate treatment of two-electron interaction in the non-quantum-electrodynamics regime. The Breit interaction in the Coulomb gauge consists of magnetic and gauge contributions. The high computational cost of the gauge term limits the application of the Breit interaction in relativistic molecular calculations. In this work, we apply the Pauli component integral–density matrix contraction scheme for gauge interaction with a maximum spin- and component separation scheme. We also present two different computational algorithms for evaluating gauge integrals. One is the generalized Obara–Saika algorithm, where the Laplace transformation is used to transform the gauge operator into Gaussian functions and the Obara–Saika recursion is used for reducing the angular momentum. The other algorithm is the second derivative of Coulomb interaction evaluated with Rys-quadrature. This work improves the efficiency of performing Dirac–Hartree–Fock with the variational treatment of Breit interaction for molecular systems. We use this formalism to examine relativistic trends in the Periodic Table and analyze the relativistic two-electron interaction contributions in heavy-element complexes.
Modified divacancies in 4H-SiC
Authors: Son N. T. , Shafizadeh D. , Ohshima T. , Ivanov I. G.
Published: July 2022

Divacancies near or at lattice defects in SiC, the PL5–PL7 photoluminescence centers, are known to have more favorable optical and spin properties for applications in quantum technology compared to the usual divacancies. These centers were previously predicted to be divacancies near stacking faults. Using electron paramagnetic resonance, we observe PL5, PL6, and four other divacancy-like centers, labeled PLa–PLd, in electron-irradiated high-purity semi-insulating (HPSI) 4H-SiC. From the observed fine-structure D-tensors, we show that these centers including PL6, which has so far been believed to be an axial center, all have C1h symmetry. Among these, PLa, PLc, and PLd are basal divacancies and PL5 and PL6 are slightly deviated from axial symmetry, while PLb is different from others with the principal Dzz axis of the D-tensor aligning at ∼34° off the c-axis. We show that these modified divacancies are only detected in one type of HPSI materials but not in commercial n- and p-type substrates or n-type pure epitaxial layers irradiated by electrons regardless of surface treatments which are known to create stacking faults.
Mixed population hypothesis of the active and inactive PSII complexes opens a new door for photoinhibition and fluorescence studies: an ecophysiological perspective
Authors: Kono Masaru , Miyata Kazunori , Matsuzawa Sae , Noguchi Takaya , Oguchi Riichi , Suzuki Yoshihiro , Terashima Ichiro
Published: July 2022

The current hypotheses for the mechanisms of photosystem II (PSII) photodamage in vivo remain split on the primary damage site. However, most researchers have considered that PSII is inhibited by a sole mechanism and that the photoinhibited PSII consists of one population. In this perspective, we propose ‘the mixed population hypothesis’, in which there are four PSII populations: PSII with active/inactive Mn4CaO5 oxygen-evolving complex respectively with functional/damaged primary quinone (QA) reduction activity. This hypothesis provides a new insight into not only the PSII photoinhibition/photoprotection studies but also the repair process. We discuss our new data implying that the repair rate differs in the respective PSII populations.
Signal binding at both modules of its dCache domain enables the McpA chemoreceptor of
Bacillus velezensis
to sense different ligands
Authors: Feng Haichao , Lv Yu , Krell Tino , Fu Ruixin , Liu Yunpeng , Xu Zhihui , Du Wenbin , Shen Qirong , Zhang Nan , Zhang Ruifu
Published: July 2022

Bacteria have evolved multiple signal transduction systems that permit an adaptation to changing environmental conditions. Chemoreceptor-based signaling cascades are very abundant in bacteria and are among the most complex signaling systems. Currently, our knowledge on the molecular features that determine signal recognition at chemoreceptors is limited. Chemoreceptor McpA of
Bacillus velezensis
SQR9 has been shown to mediate chemotaxis to a broad range of different ligands. Here we show that its ligand binding domain binds directly 13 chemoattractants. We provide support that organic acids and amino acids bind to the membrane-distal and membrane-proximal module of the dCache domain, respectively, whereas binding of sugars/sugar alcohols occurred at both modules. Structural biology studies combined with site-directed mutagenesis experiments have permitted to identify 10 amino acid residues that play key roles in the recognition of multiple ligands. Residues in membrane-distal and membrane-proximal regions were central for sensing organic acids and amimo acids, respectively, whereas all residues participated in sugars/sugar alcohol sensing. Most characterized chemoreceptors possess a narrow and well-defined ligand spectrum. We propose here a sensing mechanism involving both dCache modules that allows the integration of very diverse signals by a single chemoreceptor.
Enhanced incorporation of subnanometer tags into cellular proteins for fluorescence nanoscopy via optimized genetic code expansion
Authors: Mihaila Tiberiu S. , Bäte Carina , Ostersehlt Lynn M. , Pape Jasmin K. , Keller-Findeisen Jan , Sahl Steffen J. , Hell Stefan W.
Published: July 2022

With few-nanometer resolution recently achieved by a new generation of fluorescence nanoscopes (MINFLUX and MINSTED), the size of the tags used to label proteins will increasingly limit the ability to dissect nanoscopic biological structures. Bioorthogonal (click) chemical groups are powerful tools for the specific detection of biomolecules. Through the introduction of an engineered aminoacyl–tRNA synthetase/tRNA pair (tRNA: transfer ribonucleic acid), genetic code expansion allows for the site-specific introduction of amino acids with “clickable” side chains into proteins of interest. Well-defined label positions and the subnanometer scale of the protein modification provide unique advantages over other labeling approaches for imaging at molecular-scale resolution. We report that, by pairing a new N-terminally optimized pyrrolysyl–tRNA synthetase (chPylRS
2020
) with a previously engineered orthogonal tRNA, clickable amino acids are incorporated with improved efficiency into bacteria and into mammalian cells. The resulting enhanced genetic code expansion machinery was used to label β-actin in U2OS cell filopodia for MINFLUX imaging with minimal separation of fluorophores from the protein backbone. Selected data were found to be consistent with previously reported high-resolution information from cryoelectron tomography about the cross-sectional filament bundling architecture. Our study underscores the need for further improvements to the degree of labeling with minimal-offset methods in order to fully exploit molecular-scale optical three-dimensional resolution.
Pharmacologic modulation of intracellular Na+concentration with ranolazine impacts inflammatory response in humans and mice
Authors: Lenz Max , Salzmann Manuel , Ciotu Cosmin I. , Kaun Christoph , Krychtiuk Konstantin A. , Rehberger Likozar Andreja , Sebestjen Miran , Goederle Laura , Rauscher Sabine , Krivaja Zoriza , Binder Christoph J. , Huber Kurt , Hengstenberg Christian , Podesser Bruno K. , Fischer Michael J. M. , Wojta Johann , Hohensinner Philipp J. , Speidl Walter S.
Published: July 2022

Changes in Ca2+influx during proinflammatory stimulation modulates cellular responses, including the subsequent activation of inflammation. Whereas the involvement of Ca2+has been widely acknowledged, little is known about the role of Na+. Ranolazine, a piperazine derivative and established antianginal drug, is known to reduce intracellular Na+as well as Ca2+levels. In stable coronary artery disease patients (n= 51) we observed reduced levels of high-sensitive C-reactive protein (CRP) 3 mo after the start of ranolazine treatment (n= 25) as compared to the control group. Furthermore, we found that in 3,808 acute coronary syndrome patients of the MERLIN‐TIMI 36 trial, individuals treated with ranolazine (1,934 patients) showed reduced CRP values compared to placebo-treated patients. The antiinflammatory effects of sodium modulation were further confirmed in an atherosclerotic mouse model. LDL−/−mice on a high-fat diet were treated with ranolazine, resulting in a reduced atherosclerotic plaque burden, increased plaque stability, and reduced activation of the immune system. Pharmacological Na+inhibition by ranolazine led to reduced express of adhesion molecules and proinflammatory cytokines and reduced adhesion of leukocytes to activated endothelium both in vitro and in vivo. We demonstrate that functional Na+shuttling is required for a full cellular response to inflammation and that inhibition of Na+influx results in an attenuated inflammatory reaction. In conclusion, we demonstrate that inhibition of Na+–Ca2+exchange during inflammation reduces the inflammatory response in human endothelial cells in vitro, in a mouse atherosclerotic disease model, and in human patients.
Renormalization Group Theory of Eigen Microstates
Authors: Liu Teng , Hu Gao-Ke , Dong Jia-Qi , Fan Jing-Fang , Liu Mao-Xin , Chen Xiao-Song
Published: July 2022

We propose a renormalization group (RG) theory of eigen microstates, which are introduced in the statistical ensemble composed of microstates obtained from experiments or computer simulations. A microstate in the ensemble can be considered as a linear superposition of eigen microstates with probability amplitudes equal to their eigenvalues. Under the renormalization of a factor b, the largest eigenvalue σ
1 has two trivial fixed points at low and high temperature limits and a critical fixed point with the RG relation

σ
1
b

=

b

β
/
ν

σ
1

, where β and ν are the critical exponents of order parameter and correlation length, respectively. With the Ising model in different dimensions, it has been demonstrated that the RG theory of eigen microstates is able to identify the critical point and to predict critical exponents and the universality class. Our theory can be used in research of critical phenomena both in equilibrium and non-equilibrium systems without considering the Hamiltonian, which is the foundation of Wilson’s RG theory and is absent for most complex systems.
Transmissive and reflective switchable terahertz metasurface for phase modulation based on vanadium dioxide
Authors: Niu Junhao , Li Chunhui , Mo Wei , Yao Qianyu , Zhu Aijun
Published: July 2022

Metasurfaces provide a powerful ability to control electromagnetic waves, but most metasurfaces only work in transmission or reflection mode. In this paper, a transmissive and reflective switchable metasurface is designed. The unit structure consists of two split-rings and vanadium dioxide (VO2) film. Utilizing the phase change characteristics of VO2, the designed metasurface works in transmission mode at 25 °C, while works in reflection mode at 68 °C. It can transform the incident circularly polarized wave at the frequency of 0.47 THz, achieving transmission cross-polarization conversion amplitude greater than 0.8 and reflection cross-polarization conversion amplitude greater than 0.9. By rotating the split-rings, full 2π gradient phase distribution is achieved. The switchable metasurface has the potential to design multifunctional devices. To prove the concept, anomalous refraction and reflection, single-foci and dual-foci focusing metalens are designed. The proposed metasurface provides an effective method to design temperature controlled meta-devices and other systems in terahertz communications.
A hybrid deep learning model approach for performance index prediction of mechanical equipment
Authors: Hou Dali , Cao Mingjia
Published: July 2022

To forecast the health status of mechanical equipment in industrial production, fault diagnosis systems need a fast and accurate algorithm to forecast the important performance indexes of mechanical equipment. According to the characteristics of time series, a composite variable wavelet transform, deep autoencoder and long short-term memory (CWD-LSTM) hybrid neural network forecast algorithm is proposed to carry out one-step forecast experiments on air compressor datasets. As one of the important indexes reflecting the performance of the air compressor, loading time is usually a parameter that the fault diagnosis system needs to forecast and analyze. The experimental results show that compared with the original neural network and other similar algorithms, the CWD-LSTM algorithm has obvious advantages in forecasting the loading time under a variety of detection indexes. More importantly, CWD-LSTM does not require a high update frequency of the neural network, and manufacturers do not need a frequent training model to ensure the reliability of forecast.
Rational design of selenium inserted 1T/2H mixed-phase molybdenum disulfide for energy storage and pollutant degradation applications
Authors: Namsheer K , Thomas Siby , Sharma Aditya , Thomas Susmi Anna , Sree Raj K A , Kumar Vipin , Gagliardi Alessio , Aravind Arun , Rout Chandra Sekhar
Published: July 2022

MoS2 based materials are recognized as the promising candidate for multifunctional applications due to its unique physicochemical properties. But presence of lower number of active sites, poor electrical conductivity, and less stability of 2H and 1T MoS2 inherits its practical applications. Herein, we synthesized the Se inserted mixed-phase 2H/1T MoS2 nanosheets with abundant defects sites to achieve improved overall electrochemical activity. Moreover, the chalcogen insertion induces the recombination of photogenerated excitons and enhances the life of carriers. The bifunctional energy storage and photocatalytic pollutant degradation studies of the prepare materials are carried out. Fabricated symmetric solid-state supercapacitor showed an exceptional capacitance of 178 mF cm−2 with an excellent energy density of 8 μWh cm−2 and power density of 137 mW cm−2, with remarkable capacitance retention of 86.34% after successive 8000 charge–discharge cycles. The photocatalytic dye degradation experiments demonstrate that the prepared Se incorporated 1T/2H MoS2 is a promising candidate for dye degradation applications. Further, the DFT studies confirmed that the Se inserted MoS2 is a promising electrode material for supercapacitor applications with higher CQ
due to a larger density of states near Fermi level as compared to pristine MoS2.
Broadband photodetector based on SnTe nanofilm/n-Ge heterostructure
Authors: Song Liyuan , Tang Libin , Hao Qun , Teng Kar Seng , Lv Hao , Wang Jingyu , Feng Jiangmin , Zhou Yan , He Wenjin , Wang Wei
Published: July 2022

Combining novel two-dimensional materials with traditional semiconductors to form heterostructures for photoelectric detection have attracted great attention due to their excellent photoelectric properties. In this study, we reported the formation of a heterostructure comprising of tin telluride (SnTe) and germanium (Ge) by a simple and efficient one-step magnetron sputtering technique. A photodetector was fabricated by sputtering a nanofilm of SnTe on to a pre-masked n-Ge substrate. J–V measurements obtained from the SnTe/n-Ge photodetector demonstrated diode and photovoltaic characteristics in the visible to near-infrared (NIR) band (i.e. 400–2050 nm). Under NIR illumination at 850 nm with an optical power density of 13.81 mW cm−2, the SnTe/n-Ge photodetector exhibited a small open-circuit voltage of 0.05 V. It also attained a high responsivity (R) and detectivity (D*) of 617.34 mA W−1 (at bias voltage of −0.5 V) and 2.33 × 1011 cmHz1/2W−1 (at zero bias), respectively. Therefore, SnTe nanofilm/n-Ge heterostructure is highly suitable for used as low-power broadband photodetector due to its excellent performances and simple device configuration.
The radiosensitizing effect of platinum nanoparticles in proton irradiations is not caused by an enhanced proton energy deposition at the macroscopic scale
Authors: Behrends C , Bäcker C M , Schilling I , Zwiehoff S , Weingarten J , Kröninger K , Rehbock C , Barcikowski S , Wulff J , Bäumer C , Timmermann B
Published: July 2022

Objective. Due to the radiosensitizing effect of biocompatible noble metal nanoparticles (NPs), their administration is considered to potentially increase tumor control in radiotherapy. The underlying physical, chemical and biological mechanisms of the NPs’ radiosensitivity especially when interacting with proton radiation is not conclusive. In the following work, the energy deposition of protons in matter containing platinum nanoparticles (PtNPs) is experimentally investigated. Approach. Surfactant-free monomodal PtNPs with a mean diameter of (40 ± 10) nm and a concentration of 300 μg ml−1, demonstrably leading to a substantial production of reactive oxygen species (ROS), were homogeneously dispersed into cubic gelatin samples serving as tissue-like phantoms. Gelatin samples without PtNPs were used as control. The samples’ dimensions and contrast of the PtNPs were verified in a clinical computed tomography scanner. Fields from a clinical proton machine were used for depth dose and stopping power measurements downstream of both samples types. These experiments were performed with a variety of detectors at a pencil beam scanning beam line as well as a passive beam line with proton energies from about 56–200 MeV. Main results. The samples’ water equivalent ratios in terms of proton stopping as well as the mean proton energy deposition downstream of the samples with ROS-producing PtNPs compared to the samples without PtNPs showed no differences within the experimental uncertainties of about 2%. Significance. This study serves as experimental proof that the radiosensitizing effect of biocompatible PtNPs is not due to a macroscopically increased proton energy deposition, but is more likely caused by a catalytic effect of the PtNPs. Thus, these experiments provide a contribution to the highly discussed radiobiological question of the proton therapy efficiency with noble metal NPs and facilitate initial evidence that the dose calculation in treatment planning is straightforward and not affected by the presence of sensitizing PtNPs.
Artificial intelligence methods for applied superconductivity: material, design, manufacturing, testing, operation, and condition monitoring
Authors: Yazdani-Asrami Mohammad , Sadeghi Alireza , Song Wenjuan , Madureira Ana , Murta-Pina João , Morandi Antonio , Parizh Michael
Published: July 2022

More than a century after the discovery of superconductors (SCs), numerous studies have been accomplished to take advantage of SCs in physics, power engineering, quantum computing, electronics, communications, aviation, healthcare, and defence-related applications. However, there are still challenges that hinder the full-scale commercialization of SCs, such as the high cost of superconducting wires/tapes, technical issues related to AC losses, the structure of superconducting devices, the complexity and high cost of the cooling systems, the critical temperature, and manufacturing-related issues. In the current century, massive advancements have been achieved in artificial intelligence (AI) techniques by offering disruptive solutions to handle engineering problems. Consequently, AI techniques can be implemented to tackle those challenges facing superconductivity and act as a shortcut towards the full commercialization of SCs and their applications. AI approaches are capable of providing fast, efficient, and accurate solutions for technical, manufacturing, and economic problems with a high level of complexity and nonlinearity in the field of superconductivity. In this paper, the concept of AI and the widely used algorithms are first given. Then a critical topical review is presented for those conducted studies that used AI methods for improvement, design, condition monitoring, fault detection and location of superconducting apparatuses in large-scale power applications, as well as the prediction of critical temperature and the structure of new SCs, and any other related applications. This topical review is presented in three main categories: AI for large-scale superconducting applications, AI for superconducting materials, and AI for the physics of SCs. In addition, the challenges of applying AI techniques to the superconductivity and its applications are given. Finally, future trends on how to integrate AI techniques with superconductivity towards commercialization are discussed.
Effective field theory of waterfall in hybrid inflation
Authors: Gong Jinn-Ouk , Mylova Maria
Published: July 2022

We examine the validity of the classical approximation of the waterfall phase transition in hybrid inflation from an effective field theory (EFT) point of view. The EFT is constructed by integrating out the waterfall field fluctuations, up to one-loop order in the perturbative expansion. Assuming slow-roll conditions are obeyed, right after the onset of the waterfall phase, we find the backreaction of the waterfall field fluctuations to the evolution of the system can be dominant. In this case the classical approximation is completely spoiled. We derive the necessary constraint that ensures the validity of the EFT.
Mobile data collection of wireless sensor networks with speed control
Authors: Xin Qiangwei , Zhang Wei
Published: July 2022

Reducing delay has an important position in the data collection of wireless sensor networks. Current mobile sink may use single antenna to collect data, but necessarily use two antennas if the data amount is large. The purpose of the research is to reduce the delay of data collection. Unlike many traditional methods, our approach has not parking positions of mobile sink in the process of data collection. We propose an algorithm based on speed control of mobile sink that reduces the delay of data collection. The algorithm combines speed control and two antennas of mobile sink. Our algorithm ensures reducing the delay of data collection.
Transmission path optimization Based on Efficiency Communication System
Authors: Fan Jin , Lim Kit Guan , Ee Chuo Helen Sin , Tan Min Keng , Farzamnia Ali , Teo Kenneth Tze Kin
Published: July 2022

Routing is the core of wireless sensor network deployment. This paper points out the research focus of the wireless sensor network transmission path and discusses the optimization problem of the transmission based on grid model. In this paper, routing attribute table that is maintained by the nodes, the density and relative distance of node distribution, is used to determine the clustering method. At the same time, the developed algorithm combines the relative position of the cluster and the base station to further improve the routing method of the sub-cluster head, Finally, the algorithm analyzes the influence of different parameters on the transmission path, and use the simulation experiments to evaluate the conclusions.
Multi-messenger observations of thunderstorm-related bursts of cosmic rays
Authors: Chilingarian A. , Hovsepyan G. , Karapetyan T. , Khanykyanc Y. , Pokhsraryan D. , Sargsyan B. , Chilingaryan S. , Soghomonyan S.
Published: July 2022

We present the facilities of the Aragats Space Environmental Center in Armenia used during multi-year observations of the thunderstorm ground enhancements (TGEs) and corresponding environmental parameters. We analyze the characteristics of the detectors, operated on Aragats, and describe the coordinated detection of TGEs by the network of scintillators, field meters, and weather stations. By using a fast synchronized data acquisition system, we reveal correlations of the multivariate data on time scales from nanoseconds to minutes, which allow us to gain insight into the TGE and lightning origin and their interrelations. Also, we demonstrate how different coincidences of multilayered detector operation can select various species of secondary cosmic rays.
Resveratrol promotes osteogenesis and angiogenesis through mediating immunology of senescent macrophages
Authors: Hang Ruiqiang , Wang Jiahui , Tian Xue , Wu Ruifeng , Hang Ruiyue , Zhao Yuyu , Sun Yonghua , Wang Honggang
Published: July 2022

Orthopedic implants have been used clinically to restore the functions of the compromised bone tissues, but there is still a relatively high risk of failure for elderly people. A critical reason is pro-inflammatory immune microenvironment created by senescent macrophages with homeostasis imbalance impairs osteogenesis and angiogenesis, two major processes involved in implant osseointegration. The present work proposes to use resveratrol as an autophagy inducing agent to upregulate the autophagy level of senescent macrophages to restore homeostasis, consequently generating a favorable immune microenvironment. The results show 0.1–1 μM of resveratrol can induce autophagy of senescent macrophages, promote cell viability and proliferation, reduce intracellular reactive oxygen species level, and polarize the cells to pro-healing M2 phenotype. The immune microenvironment created by senescent macrophages upon resveratrol stimulation can promote osteogenesis and angiogenesis, as manifested by upregulated proliferation, alkaline phosphatase activity, type I collagen secretion, and extracellular matrix mineralization of senescent osteoblasts as well as nitric oxide production, migration, and in vitro angiogenesis of senescent endothelial cells. In addition, resveratrol-loaded silk fibroin coatings can be fabricated on titanium surface through electrophoretic co-deposition and the coatings show beneficial effects on the functions of senescent macrophages. Our results suggest resveratrol can be used as surface additive of titanium implants to promote osseointegration of elderly people though regulating immunology of senescent macrophages.
Explicit Tamagawa numbers for certain algebraic tori over number fields
Authors: Rüd Thomas
Published: July 2022

Given a number field extension

K

/

k

K/k

with an intermediate field

K
+

K^+

fixed by a central element of

Gal
⁡
(
K

/

k
)

\operatorname {Gal}(K/k)

of prime order

p
p

, there exists an algebraic torus over

k
k

whose rational points are elements of

K
×

K^\times

sent to

k
×

k^\times

by the norm map

N

K

/

K
+

N_{K/K^+}

. The goal is to compute the Tamagawa number such a torus explicitly via Ono’s formula that expresses it as a ratio of cohomological invariants. A fairly complete and detailed description of the cohomology of the character lattice of such a torus is given when

K

/

k

K/k

is Galois. Partial results including the numerator of Ono’s formula are given when the extension is not Galois, or more generally when the torus is defined by an étale algebra.

We also present tools developed in SageMath for this purpose, allowing us to build and compute the cohomology and explore the local-global principles for such an algebraic torus.

Particular attention is given to the case when

[
K
:

K
+

]
=
2

[K:K^+]=2

and

K
K

is a CM-field. This case corresponds to maximal tori in

G
S
p

2
n

\mathrm {GSp}_{2n}

, and most examples will be in that setting. This is motivated by the application to abelian varieties over finite fields and the Hasse principle for bilinear forms.
Genetic risk for schizophrenia is associated with increased proportion of indirect connections in brain networks revealed by a semi-metric analysis: evidence from population sample stratified for polygenic risk
Authors: Dimitriadis S I , Perry G , Lancaster T M , Tansey K E , Singh K D , Holmans P , Pocklington A , Davey Smith G , Zammit S , Hall J , O’Donovan M C , Owen M J , Jones D K , Linden D E
Published: July 2022

Research studies based on tractography have revealed a prominent reduction of asymmetry in some key white-matter tracts in schizophrenia (SCZ). However, we know little about the influence of common genetic risk factors for SCZ on the efficiency of routing on structural brain networks (SBNs). Here, we use a novel recall-by-genotype approach, where we sample young adults from a population-based cohort (ALSPAC:N genotyped = 8,365) based on their burden of common SCZ risk alleles as defined by polygenic risk score (PRS). We compared 181 individuals at extremes of low (N = 91) or high (N = 90) SCZ-PRS under a robust diffusion MRI-based graph theoretical SBN framework. We applied a semi-metric analysis revealing higher SMR values for the high SCZ-PRS group compared with the low SCZ-PRS group in the left hemisphere. Furthermore, a hemispheric asymmetry index showed a higher leftward preponderance of indirect connections for the high SCZ-PRS group compared with the low SCZ-PRS group (PFDR < 0.05). These findings might indicate less efficient structural connectivity in the higher genetic risk group. This is the first study in a population-based sample that reveals differences in the efficiency of SBNs associated with common genetic risk variants for SCZ.
Unsedated transnasal endoscopy for the detection of Barrett’s esophagus: systematic review and meta-analysis
Authors: Huibertse Lotte J , Peters Yonne , Westendorp Dieuwertje , Siersema Peter D
Published: July 2022

Conventional esophagogastroduodenoscopy (cEGD) is currently the gold standard endoscopic procedure for diagnosis and surveillance of Barrett’s esophagus (BE). This procedure is however less suitable for widespread screening because of its invasiveness and costs. An alternative endoscopic procedure is unsedated transnasal endoscopy (uTNE). We performed a systematic review and meta-analysis to evaluate the diagnostic accuracy, patient tolerability, technical success rate, and safety of uTNE compared with cEGD for detecting BE and related neoplasia. PubMed, EMBASE, and Cochrane Library were searched for studies that reported the diagnostic accuracy of uTNE compared with cEGD for detecting BE and related neoplasia. Eight prospective studies were included, in which 623 patients underwent both uTNE and cEGD. Pooled sensitivity and specificity of uTNE for detecting columnar epithelium were 98% (95% CI 83–100%) and 99% (95% CI 82–100%), respectively. Pooled sensitivity and specificity of uTNE for detecting intestinal metaplasia in biopsies were 89% (95% CI 78–95%) and 93% (95% CI 71–98%), respectively. In three of the six studies that reported patient tolerability, a higher patient tolerability of uTNE compared with cEGD was reported. The technical success rate of uTNE ranged from 89% to 100% and no (serious) adverse events were reported. This systematic review and meta-analysis provides evidence that uTNE is an accurate, safe, and well-tolerated procedure for the detection of columnar epithelium and can be considered as screening modality for BE.
Clinical implications of chyle leakage following esophagectomy
Authors: Schafrat Pascale J M , Henckens Sofie P G , Hagens Eliza R C , Eshuis Wietse J , Gisbertz Suzanne S , Laméris Wytze , van Berge Henegouwen Mark I
Published: July 2022

The clinical consequences of chyle leakage following esophagectomy are underexposed. The aim of this study was to investigate the clinical implications of chyle leakage following esophagectomy. This retrospective study of prospectively collected data included patients who underwent transthoracic esophagectomy in 2017–2020. Routinely, the thoracic duct was resected en bloc as part of the mediastinal lymphadenectomy. Chyle leakage was defined as milky drain fluid for which specific treatment was initiated and/or a triglyceride level in drain fluid of ≥1.13 mmol/L, according to the Esophagectomy Complications Consensus Group (ECCG) classification. Primary endpoints were the clinical characteristics of chyle leakage (type, severity and treatment). Secondary endpoints were the impact of chyle leakage on duration of thoracic drainage and hospital stay. Chyle leakage was present in 43/314 patients (14%), of whom 24 (56%) were classified as severity A and 19 (44%) as severity B. All patients were successfully treated with either medium chain triglyceride diet (98%) or total parental nutrition (2%). There were no re-interventions for chyle leakage during initial admission, although one patient needed additional pleural drainage during readmission. Patients with chyle leakage had 3 days longer duration of thoracic drainage (bias corrected accelerated (BCa) 95%CI:0.46–0.76) and 3 days longer hospital stay (BCa 95%CI:0.07–0.36), independently of the presence of other complications. Chyle leakage is a relatively frequent complication following esophagectomy. Postoperative chyle leakage was associated with a significant longer duration of thoracic drainage and hospital admission. Nonsurgical treatment was successful in all patients with chyle leakage.
TRPM4 inhibition by meclofenamate suppresses Ca2+-dependent triggered arrhythmias
Authors: Vandewiele Frone , Pironet Andy , Jacobs Griet , Kecskés Miklos , Wegener Jörg , Kerselaers Sara , Hendrikx Lio , Verelst Joren , Philippaert Koenraad , Oosterlinck Wouter , Segal Andrei , Van Den Broeck Evy , Pinto Silvia , Priori Silvia G , Lehnart Stephan E , Nilius Bernd , Voets Thomas , Vennekens Rudi
Published: July 2022

Aims

Cardiac arrhythmias are a major factor in the occurrence of morbidity and sudden death in patients with cardiovascular disease. Disturbances of Ca2+ homeostasis in the heart contribute to the initiation and maintenance of cardiac arrhythmias. Extrasystolic increases in intracellular Ca2+ lead to delayed afterdepolarizations and triggered activity, which can result in heart rhythm abnormalities. It is being suggested that the Ca2+-activated nonselective cation channel TRPM4 is involved in the aetiology of triggered activity, but the exact contribution and in vivo significance are still unclear.

Methods and results

In vitro electrophysiological and calcium imaging technique as well as in vivo intracardiac and telemetric electrocardiogram measurements in physiological and pathophysiological conditions were performed. In two distinct Ca2+-dependent proarrhythmic models, freely moving Trpm4−/− mice displayed a reduced burden of cardiac arrhythmias. Looking further into the specific contribution of TRPM4 to the cellular mechanism of arrhythmias, TRPM4 was found to contribute to a long-lasting Ca2+ overload-induced background current, thereby regulating cell excitability in Ca2+ overload conditions. To expand these results, a compound screening revealed meclofenamate as a potent antagonist of TRPM4. In line with the findings from Trpm4−/− mice, 10 µM meclofenamate inhibited the Ca2+ overload-induced background current in ventricular cardiomyocytes and 15 mg/kg meclofenamate suppressed catecholaminergic polymorphic ventricular tachycardia-associated arrhythmias in a TRPM4-dependent manner.

Conclusion

The presented data establish that TRPM4 represents a novel target in the prevention and treatment of Ca2+-dependent triggered arrhythmias.
New Pneumococcal Vaccines for Prevention of Invasive Pneumococcal Disease in Adult Patients With Inflammatory Bowel Disease
Authors: Crosby Sheena , Schuh Michael J , Becker Michelle , Ivanov Marina , Caldera Freddy , Farraye Francis A
Published: July 2022

Patients with inflammatory bowel disease (IBD) are at a high risk of developing invasive pneumococcal infection both before and after they are diagnosed. The Advisory Committee on Immunization Practices now endorses use of 2 new pneumococcal conjugate vaccines, PCV15 (Vaxneuvance) and PCV20 (Prevnar 20), for patients who have never received a pneumococcal conjugate vaccine or those with unknown vaccination history. Previous studies have shown that pneumococcal vaccination can decrease the risk of developing severe pneumococcal disease; therefore, it is important that patients with IBD receive pneumococcal vaccination. This report aims to inform clinicians who care for patients with IBD about the changes in immunization practices, as it pertains to pneumococcal vaccination and provides appropriate direction on administering vaccination series.
Differing associations with childhood outcomes using behavioural patterns derived from three data reduction techniques
Authors: D’Souza Ninoshka J , Zheng Miaobing , Abbott Gavin , Lioret Sandrine , Hesketh Kylie D
Published: July 2022

Background

Behavioural patterns help to understand the influence of multiple health behaviours on childhood outcomes. Behavioural patterns derived using different data reduction techniques can be non-identical and may differentially associate with childhood outcomes. This study aimed to compare associations of behavioural patterns derived from three methods with three childhood outcomes.

Methods

Data were from the Healthy Active Preschool and Primary Years study when children were 6–8 years old (n = 432). Cluster analysis (CA), latent profile analysis (LPA) and principal component analysis (PCA) were used to derive behavioural patterns from children’s diet, physical activity, sedentary behaviour and sleep data. Behavioural data were obtained through parent report and accelerometry. Children’s height, weight and waist circumference were measured by trained study staff. Health-related quality of life data were obtained using the Pediatric Quality of Life Inventory and academic performance scores were from a national test. Associations between derived patterns from each method and each of the outcomes were tested using linear regression (adjusted for child age and sex and parent education).

Results

Three patterns were each derived using CA and LPA, and four patterns were derived using PCA. Each method identified a healthy, an unhealthy and a mixed (comprising healthy and unhealthy behaviours together) pattern. Differences in associations were observed between pattern groups from CA and LPA and pattern scores from PCA with the three outcomes.

Conclusions

Discrepancies in associations across pattern derivation methods suggests that the choice of method can influence subsequent associations with outcomes. This has implications for comparison across studies that have employed different methods.
Ageism in healthcare technology: the older patients’ aspirations for improved online accessibility
Authors: Zoorob Dani , Hasbini Yasmin , Chen Katherine , Wangia-Anderson Victoria , Moussa Hind , Miller Brian , Brobst Debi
Published: July 2022

Objective

To identify concerns, barriers and facilitators impacting the use of patient portals by older patients as well as desired features in future updates.

Materials and Methods

This is a cross-sectional study consisting of 2 focus group discussions culminating in an anonymous survey administered to women who were 65 years and older receiving urogynecologic care in Northwest Ohio.

Results

Of the 205 women surveyed (91% response rate), providers and healthcare systems play the primary 2 roles (73% and 69%, respectively) in facilitating patients’ use of patient portal systems and telehealth applications. Barriers to use revolved around technical difficulties (50%), privacy concerns (45%), and cost of technology (24%). The most important features desired were the ability to modify the text size within the application (47%) and an intuitive, simple interface (46%). Additional assistance for navigating technical challenges was suggested, specifically set-up of accounts (36%), saving and sharing information with caregivers (35%), and sign-in and navigation of portals (32%).

Conclusion

The paucity of age-aligned medical access software and products may lead to worsening of digital exclusion and disparities in healthcare. Portal application developers and healthcare systems must advance efforts that consider the needs of those who may be older when designing patient portals.
Recent advances in the management of older adults with newly diagnosed multiple myeloma in Japan
Authors: Suzuki Tomotaka , Maruyama Dai , Iida Shinsuke , Nagai Hirokazu
Published: July 2022

Multiple myeloma is a cancer of plasma cells; the incidence rate of multiple myeloma is high among older adults. Although significant advances have been made in the clinical management of multiple myeloma driven by the introduction of novel drugs, such as proteasome inhibitors, immuno- modulators and antibodies, multiple myeloma remains incurable. Hence, the current therapeutic goal for multiple myeloma is to achieve long-term survival while maintaining a good quality of life. In this context, personalized treatment to balance the efficacy and safety of therapies is important, especially for older adults as they display diverse physical, cognitive or organ functioning. Furthermore, old age is also often associated with frailty. Several tools for evaluating frailty in older adults with multiple myeloma are now available, and frail patients defined by these tools have shown a poor prognosis and more treatment-related toxicities. In addition, it is important to evaluate other factors, such as the International Staging System, high-risk chromosomal abnormalities and treatment response, to predict the clinical course of patients. Further investigations are required to determine how these factors can optimize the treatment for multiple myeloma. In this review, we present a detailed account on the developments and issues related to the current treatment approaches for older adults with newly diagnosed multiple myeloma. We also discuss the ongoing phase III clinical study conducted by the lymphoma study group of the Japan Clinical Oncology Group, which targeted older adults with newly diagnosed multiple myeloma.
Arecibo and FAST timing follow-up of 12 millisecond pulsars discovered in Commensal Radio Astronomy FAST Survey
Authors: Miao C C , Zhu W W , Li D , Freire P C C , Niu J R , Wang P , Yuan J P , Xue M Y , Cameron A D , Champion D J , Cruces M , Chen Y T , Chi M M , Cheng X F , Dang S J , Ding M F , Feng Y , Gan Z Y , Hobbs G , Kramer M , Liu Z J , Li Y X , Luo Z K , Miao X L , Meng L Q , Niu C H , Pan Z C , Qian L , Sun Z Y , Wang N , Wang S Q , Wang J B , Wu Q D , Wang Y B , Wang C J , Wang H F , Wang S , Xie X Y , Xie M , Xiao Y F , Yuan M , Yue Y L , Yao J M , Yan W M , You S P , Yu X H , Zhao D , Zhao R S , Zhang L
Published: July 2022

We report the phase-connected timing ephemeris, polarization pulse profiles, Faraday rotation measurements, and Rotating-Vector-Model (RVM) fitting results of 12 millisecond pulsars (MSPs) discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in the Commensal Radio Astronomy FAST survey (CRAFTS). The timing campaigns were carried out with FAST and Arecibo over 3 yr. 11 of the 12 pulsars are in neutron star–white dwarf binary systems, with orbital periods between 2.4 and 100 d. 10 of them have spin periods, companion masses, and orbital eccentricities that are consistent with the theoretical expectations for MSP–Helium white dwarf (He WD) systems. The last binary pulsar (PSR J1912−0952) has a significantly smaller spin frequency and a smaller companion mass, the latter could be caused by a low orbital inclination for the system. Its orbital period of 29 d is well within the range of orbital periods where some MSP–He WD systems have shown anomalous eccentricities, however, the eccentricity of PSR J1912−0952 is typical of what one finds for the remaining MSP–He WD systems.
Galactic seismology: joint evolution of impact-triggered stellar and gaseous disc corrugations
Authors: Tepper-García Thor , Bland-Hawthorn Joss , Freeman Ken
Published: July 2022

Evidence for wave-like corrugations are well established in the Milky Way and in nearby disc galaxies. These were originally detected as a displacement of the interstellar medium about the mid-plane, either in terms of vertical distance or vertical velocity. Over the past decade, similar patterns have emerged in the Milky Way’s stellar disc. We investigate how these vertical waves are triggered by a passing satellite. Using high-resolution N-body/hydrodynamical simulations, we systematically study how the corrugations set up and evolve jointly in the stellar and gaseous discs. We find that the gas corrugations follow the stellar corrugations, i.e. they are initially in phase although, after a few rotation periods (500–700 Myr), the distinct waves separate and thereafter evolve in different ways. The spatial and kinematic amplitudes (and thus the energy) of the corrugations dampen with time, with the gaseous corrugation settling at a faster rate (∼800 Myr versus ∼1 Gyr). In contrast, the vertical energy of individual disc stars is fairly constant throughout the galaxy’s evolution. This difference arises because corrugations are an emergent phenomenon supported by the collective, ordered motions of co-spatial ensembles of stars. We show that the damping of the stellar corrugations can be understood as a consequence of incomplete phase mixing, while the damping of the gaseous corrugations is a natural consequence of the dissipative nature of the gas. We suggest that – in the absence of further, strong perturbations – the degree of correlation between the stellar and gaseous waves may help to age-date the phenomenon.