bluuebunny/crossref_metadata_2025 huggingface dataset:
Xanthomonas immunity proteins protect against the cis-toxic effects of their cognate T4SS effectors
Authors: Oka Gabriel U , Souza Diorge P , Sgro Germán G , Guzzo Cristiane R , Dunger German , Farah Chuck S
Published: February 2024

Many bacteria kill rival species by translocating toxic effectors into target cells. Effectors are often encoded along with cognate immunity proteins that could (i) protect against “friendly-fire” (trans-intoxication) from neighboring sister cells and/or (ii) protect against internal cis-intoxication (suicide). Here, we distinguish between these two mechanisms in the case of the bactericidal Xanthomonas citri Type IV Secretion System (X-T4SS). We use a set of X. citri mutants lacking multiple effector/immunity protein (X-Tfe/X-Tfi) pairs to show that X-Tfis are not absolutely required to protect against trans-intoxication by wild-type cells. Our investigation then focused on the in vivo function of the lysozyme-like effector X-TfeXAC2609 and its cognate immunity protein X-TfiXAC2610. In the absence of X-TfiXAC2610, we observe X-TfeXAC2609-dependent and X-T4SS-independent accumulation of damage in the X. citri cell envelope, cell death, and inhibition of biofilm formation. While immunity proteins in other systems have been shown to protect against attacks by sister cells (trans-intoxication), this is an example of an antibacterial secretion system in which the immunity proteins are dedicated to protecting cells against cis-intoxication.
Sirt6 ablation in the liver causes fatty liver that increases cancer risk by upregulating Serpina12
Authors: Li Licen , Zeng Jianming , Zhang Xin , Feng Yangyang , Lei Josh Haipeng , Xu Xiaoling , Chen Qiang , Deng Chu-Xia
Published: February 2024

Non-alcoholic fatty liver disease is a chronic liver abnormality that exhibits high variability and can lead to liver cancer in advanced stages. Hepatic ablation of SIRT6 results in fatty liver disease, yet the potential mechanism of SIRT6 deficiency, particularly in relation to downstream mediators for NAFLD, remains elusive. Here we identify Serpina12 as a key gene regulated by Sirt6 that plays a crucial function in energy homeostasis. Specifically, Sirt6 suppresses Serpina12 expression through histone deacetylation at its promoter region, after which the transcription factor, Cebpα, binds to and regulates its expression. Sirt6 deficiency results in an increased expression of Serpina12 in hepatocytes, which enhances insulin signaling and promotes lipid accumulation. Importantly, CRISPR-Cas9 mediated Serpina12 knockout in the liver ameliorated fatty liver disease caused by Sirt6 ablation. Finally, we demonstrate that Sirt6 functions as a tumor suppressor in the liver, and consequently, deletion of Sirt6 in the liver leads to not only the spontaneous development of tumors but also enhanced tumorigenesis in response to DEN treatment or under conditions of obesity.
TGFβ-induced long non-coding RNA LINC00313 activates Wnt signaling and promotes cholangiocarcinoma
Authors: Papoutsoglou Panagiotis , Pineau Raphaël , Leroux Raffaële , Louis Corentin , L’Haridon Anaïs , Foretek Dominika , Morillon Antonin , Banales Jesus M , Gilot David , Aubry Marc , Coulouarn Cédric
Published: February 2024

Cholangiocarcinoma is a devastating liver cancer characterized by high aggressiveness and therapy resistance, resulting in poor prognosis. Long non-coding RNAs and signals imposed by oncogenic pathways, such as transforming growth factor β (TGFβ), frequently contribute to cholangiocarcinogenesis. Here, we explore novel effectors of TGFβ signalling in cholangiocarcinoma. LINC00313 is identified as a novel TGFβ target gene. Gene expression and genome-wide chromatin accessibility profiling reveal that nuclear LINC00313 transcriptionally regulates genes involved in Wnt signalling, such as the transcriptional activator TCF7. LINC00313 gain-of-function enhances TCF/LEF-dependent transcription, promotes colony formation in vitro and accelerates tumour growth in vivo. Genes affected by LINC00313 over-expression in CCA tumours are associated with KRAS and TP53 mutations and reduce overall patient survival. Mechanistically, ACTL6A and BRG1, subunits of the SWI/SNF chromatin remodelling complex, interact with LINC00313 and affect TCF7 and SULF2 transcription. We propose a model whereby TGFβ induces LINC00313 in order to regulate the expression of hallmark Wnt pathway genes, in co-operation with SWI/SNF. By modulating key genes of the Wnt pathway, LINC00313 fine-tunes Wnt/TCF/LEF-dependent transcriptional responses and promotes cholangiocarcinogenesis.
PRAMEL7 and CUL2 decrease NuRD stability to establish ground-state pluripotency
Authors: Rupasinghe Meneka , Bersaglieri Cristiana , Leslie Pedrioli Deena M , Pedrioli Patrick GA , Panatta Martina , Hottiger Michael O , Cinelli Paolo , Santoro Raffaella
Published: February 2024

Pluripotency is established in E4.5 preimplantation epiblast. Embryonic stem cells (ESCs) represent the immortalization of pluripotency, however, their gene expression signature only partially resembles that of developmental ground-state. Induced PRAMEL7 expression, a protein highly expressed in the ICM but lowly expressed in ESCs, reprograms developmentally advanced ESC+serum into ground-state pluripotency by inducing a gene expression signature close to developmental ground-state. However, how PRAMEL7 reprograms gene expression remains elusive. Here we show that PRAMEL7 associates with Cullin2 (CUL2) and this interaction is required to establish ground-state gene expression. PRAMEL7 recruits CUL2 to chromatin and targets regulators of repressive chromatin, including the NuRD complex, for proteasomal degradation. PRAMEL7 antagonizes NuRD-mediated repression of genes implicated in pluripotency by decreasing NuRD stability and promoter association in a CUL2-dependent manner. Our data link proteasome degradation pathways to ground-state gene expression, offering insights to generate in vitro models to reproduce the in vivo ground-state pluripotency.
Comment on “A single level tunneling model for molecular junctions: evaluating the simulation methods” by E. M. Opodi, X. Song, X. Yu and W. Hu, Phys. Chem. Chem. Phys., 2022, 24, 11958”
Authors: Bâldea Ioan
Published: February 2024

Simplified analytic formulas for tunneling nanojunctions represent adequate approximations of the exact current provided that they are utilized within parameter ranges indicated by theory. Utilization outside the range of validity is meaningless.
Temperature-dependent hole mobility in pyrene–thiophene-based room-temperature discotic liquid crystals
Authors: Dhingra Shallu , Gupta Santosh Prasad , Shah Asmita , Singh Dharmendra Pratap , Pal Santanu Kumar
Published: February 2024

π-Conjugated pyrene–thiophene-based room-temperature discotic liquid crystals showing temperature-dependent hole mobility measured using the time-of-flight technique.
Phosphorous nitride dots induced efficient advanced oxidation with intrinsic chemiluminescence for organic pollutant degradation
Authors: Gou Jing , Sun Tong , Zhou Yuxian , Liu Houjing
Published: February 2024

In this work, we introduced novel metal-free catalysts, phosphorus nitride dots (PNDs), to generate abundant reactive oxygen species (ROS) with strong intrinsic chemiluminescence (CL).
The optimal high-temperature piezoelectric cuts of α-BiB3O6 crystals and their fatigue behaviors at high-temperature and low-pressure
Authors: Xu Mengyan , Ma Zhihong , Wang Guoliang , Peng Xiangkang , Liu Zijian , Liu Wei , Zhao Xian , Yu Fapeng
Published: February 2024

The optimal piezoelectric crystal cut of the α-BiB3O6 crystal exhibited excellent temperature stability over a wide temperature range of 20–650 °C.
Phonon dynamic behaviors induced by amorphous layers at heterointerfaces
Authors: Wang Quanjie , Zhang Jie , Xiong Yucheng , Li Shouhang , Chernysh Vladimir , Liu Xiangjun
Published: February 2024

An amorphous layer is commonly found at the interfaces of heterostructures due to lattice and thermal mismatch between dissimilar materials.
Dynamic repulsive interaction enables an asymmetric electron–phonon coupling for improving Raman scattering
Authors: Shen Jiawei , Zhang Jiaxin , Fu Zirui , Pan Yan , Li Xiaowan , Wu Shuyi , Shan Yun , Liu Lizhe
Published: February 2024

Two-dimensional (2D) materials are an excellent platform for surface-enhanced Raman spectroscopy (SERS).
Holey penta-hexagonal graphene: a promising anode material for Li-ion batteries
Authors: Lu Linguo , Gallenstein Raven , Liu Xinghui , Lin Yi , Lin Shiru , Chen Zhongfang
Published: February 2024

Holey penta-hexagonal graphene designed from molecular building blocks exhibits a high theoretical capacity (1094 mA h g−1), a low open-circuit voltage (0.29 V) and a low ion migration barrier (0.32 eV).
Electron stimulated desorption from condensed benzene
Authors: Álvarez L. , Bass A. D. , Lozano A. I. , García-Abenza A. , Limão-Vieira P. , Sanche L. , García G.
Published: February 2024

Electron induced dissociation of condensed benzene (C6H6) in thin films on a Pt substrate is investigated by the electron stimulated desorption of anions and cations. Desorption yields and effective dipolar dissociation cross-sections are obtained.
Ultrafast μLIBS imaging for the multiscale mineralogical characterization of pegmatite rocks
Authors: Alvarez-Llamas Cesar , Tercier Adrian , Ballouard Christophe , Fabre Cecile , Hermelin Sylvain , Margueritat Jeremie , Duponchel Ludovic , Dujardin Christophe , Motto-Ros Vincent
Published: February 2024

This article presents an innovative application of kHz regime μLIBS – Laser-Induced Breakdown Spectroscopy for generating detailed compositional maps of geological samples.
An efficient asymmetric structured hole transport material for perovskite solar cells
Authors: Peng Dan , Xia Ziyang , Wang Haoxin , Chen Cheng , Zhai Mengde , Tian Yi , Cheng Ming
Published: February 2024

A novel asymmetric hole transport material is developed for perovskite solar cells, achieving an efficiency of 23.1%.
Assembly of thermostable fused compounds with oxidizers for laser-ignited energetic materials
Authors: Lv Hongyu , Song Siwei , Yin Dangyue , Jiang Xiue , Li Yang , Li Zhiwei , Ao Wen , Wang Yi , Zhang Qinghua
Published: February 2024

Two new energetic materials that can be ignited by laser were synthesized by coulomb-driven self-assembly, which showed good stability, as well as excellent energetic and propulsion performances.
B(C6F5)3-catalysed isomerization of terminal olefins
Authors: Wang He , Meng Fanwei , Tao Xin
Published: February 2024

This work presents a B(C6F5)3-catalysed isomerization of terminal olefins. The more challenging linear α-olefins could be isomerized to linear 2-olefins in good yield with relatively lower E/Z selectivity, compared with allylbenzene substrates.
On multiple handoff blocking‐then‐reaccess for opportunistic spectrum access
Authors: Zhang Jing , Liang Chu‐Long , Gao Hong‐Xu , He Yan , Zhu Hong‐Bo
Published: February 2024

Opportunistic spectrum access (OSA), a promising technology to resolve radio spectrum scarcity, is still faced with some challenges, of which one is potentially frequent channel handoff (CH) even handoff blocking (HB) for secondary user (SU) to avoid primary user (PU). Reaccess is a direct way to resolve HB. However, multiple handoff blocking‐then‐reaccess (H‐BTR) are time consuming. Whether it is worthwhile to make multiple H‐BTR, is an interesting but hardly mentioned issue. To this end, the multiple H‐BTR‐based OSA are focused on here. Three key indices, the average transmission probability, handoff delay, and average reaccess times of SU in the H‐BTR‐based OSA, are deduced as close form first. Then, the effects of H‐BTR frequency and service traffic rate of SU on OSA are discussed. Finally, the H‐BTR‐based OSA is compared to two other schemes, the handoff without BTR (HWBTR)‐based OSA and the stop‐and‐waiting (SW)‐based OSA. Theoretical and simulated results show that the H‐BTR‐based OSA performs best among three schemes. Making H‐BTR in moderate frequency according to service traffic rate can increase transmission opportunity while additional delay of SU is tolerable, thus the performance of OSA can be well improved.
Post-COVID in women after SARS-CoV-2 infection during pregnancy
– a pilot study with follow-up data from the COVID-19-related Obstetric
and Neonatal Outcome Study (CRONOS)
Authors: Backes Clara , Pecks Ulrich , Keil Corinna Nora , Zöllkau Janine , Scholz Christoph , Hütten Matthias , Rüdiger Mario , Büchel Johanna , Andresen Kristin , Mand Nadine
Published: February 2024

Background Pregnant women are at an increased risk of severe COVID-19 and
adverse pregnancy outcomes; data on maternal long-term outcome is scarce. We
analyzed long-term follow-ups on women who experienced a SARS-CoV-2 infection
during pregnancy to evaluate post-COVID symptoms, particularly fatigue, and
their association with quality of life (QoL).

Methods 773 women who enrolled in the CRONOS registry between April 2020
and August 2021 were contacted for follow-up from December 2022 to April 2023.
Data was gathered through a web-based questionnaire. Subsequently, study
coordinators matched the follow-up data with the existing CRONOS data.

Results 110/773 (14%) women provided data. 20.9%
experienced only acute symptoms during their SARS-CoV-2 infection in pregnancy,
while 2.7% women experienced symptoms lasting longer than 4 weeks (long
COVID). Symptoms lasting longer than 12 weeks (post-COVID) were reported by
63.6% women and occurred more often after severe COVID-19. Fatigue was
the most frequently reported symptom (88%), with 55% of women
still experiencing it more than one year after initial infection. 76% of
women rated their QoL as “good” or “very good”.
Women experiencing post-COVID reported a significantly lower QoL.

Conclusion This is the first German long-term data on women after
SARS-CoV-2 infection during pregnancy, showing a high rate of post-COVID, a
persistence of fatigue, and the impact on QoL. Continuous monitoring of pregnant
women with COVID-19 is needed to develop comprehensive management
strategies.
Evolution of Fetal Growth in Symptomatic Sars-Cov-2
Pregnancies
Authors: Hachenberg Jens , Guenther Julia , Steinkasserer Lena , Brodowski Lars , Dueppers Ansgard Lena , Delius Maria , Chiaie Loredana Delle , Lobmaier Silvia , Sourouni Marina , Richter Manuela F. , Manz Jula , Parchmann Olaf , Schmidt Saskia , Winkler Jennifer , Werring Pia , Kraft Katrina , Kunze Mirjam , Manz Maike , Eichler Christian , Schaefer Viola , Berghaeuser Martin , Schlembach Dietmar , Seeger Sven , Schäfer-Graf Ute , Kyvernitakis Ioannis , Bohlmann Michael K. , Ramsauer Babette , Morfeld Christine Angela , Ruediger Mario , Pecks Ulrich , von Kaisenberg Constantin
Published: February 2024

Introduction SARS-CoV-2 is a viral disease with potentially devastating
effects. Observational studies of pregnant women infected with SARS-CoV-2 report
an increased risk for FGR. This study utilizes data from a prospective
SARS-CoV-2 registry in pregnancy, investigating the progression of fetuses to
fetal growth restriction (FGR) at birth following maternal SARS-CoV-2 and
evaluating the hypothesis of whether the percentage of SGA at birth is increased
after maternal SARS-CoV-2 taking into account the time interval between
infection and birth.

Materials & Methods CRONOS is a prospective German registry
enrolling pregnant women with confirmed SARS-CoV-2 infection during their
pregnancy. SARS-CoV-2 symptoms, pregnancy- and delivery-specific information
were recorded. The data evaluated in this study range from March 2020 until
August 2021. Women with SARS-CoV-2 were divided into three groups according to
the time of infection/symptoms to delivery: Group I<2 weeks,
Group II 2–4 weeks, and Group III>4 weeks. FGR was defined as
estimated and/or birth weight<10% ile, appropriate for
gestational age (AGA) was within 10 and 90%ile, and large for
gestational age (LGA) was defined as fetal or neonatal
weight>90%ile.

Results Data for a total of 2,650 SARS-CoV-2-positive pregnant women were
available. The analysis was restricted to symptomatic cases that delivered after
24+0 weeks of gestation. Excluding those cases with missing values for
estimated fetal weight at time of infection and/or birth weight centile,
900 datasets remained for analyses. Group I consisted of 551 women, Group II of
112 women, and Group III of 237 women. The percentage of changes from AGA to FGR
did not differ between groups. However, there was a significantly higher rate of
large for gestational age (LGA) newborns at the time of birth compared to the
time of SARS-CoV-2 infection in Group III (p=0.0024), respectively.

Conclusion FGR rates did not differ between symptomatic COVID infections
occurring within 2 weeks and>4 weeks before birth. On the contrary, it
presented a significant increase in LGA pregnancies in Group III. However, in
this study population, an increase in the percentage of LGA may be attributed to
pandemic measures and a reduction in daily activity.
Identification of Patients with Early HR+ HER2− Breast Cancer at High Risk of Recurrence
Authors: Fasching Peter A. , Kreipe Hans , Del Mastro Lucia , Ciruelos Eva , Freyer Gilles , Korfel Agnieszka , Chouaki Nadia , Stoffregen Clemens , Sapunar Francisco , Cameron David
Published: February 2024

Breast cancer incidence has increased in the last two decades and, simultaneously, survival has improved due to earlier detection and improved treatment options. Despite this improvement,
locoregional recurrences and distant metastases occur in up to 10 and 30% of women diagnosed with early breast cancer, respectively. Around 70% of breast cancers are hormone receptor
positive (HR+), human epidermal growth factor receptor 2 negative (HER2−), and associated with a persistent risk of relapse up to 20 years after diagnosis/initial treatment. We conducted a
narrative review by combining PubMed searches with our clinical experience to describe patient characteristics, biomarkers, and genomic profiling tools available to clinicians for the
identification of patients with HR+, HER2− early breast cancer at high risk of recurrence and to provide recommendations to classify patients into recurrence risk categories. National and
international treatment guidelines are also summarised. Accurate assessment of the risk of recurrence in these patients is crucial as the predicted risk guides treatment decisions; imprecise
estimations can result in over- or undertreatment, with either scenario having negative consequences for patients. Multiple prognostic tools and factors are recommended for early breast
cancer, and no single test provides accurate prognosis in isolation. Since no single test can provide accurate prognosis in isolation, a combination of tools should be used. Risk thresholds
are important to guide optimised and balanced therapeutic decisions in HR+, HER2− early breast cancer. However, prognostic assessment should be performed on a case-by-case basis, making
patient-specific prognostic approaches essential to avoid over- or undertreatment.
Allelic Variants of the Complement Genes in Acute Postinfectious
Glomerulonephritis
Authors: Leventoğlu Emre , Öğüt Betül , Gönül İpek Işık , Fidan Kibriya , Söylemezoğlu Oğuz
Published: February 2024

Introduction

Acute postinfectious glomerulonephritis (APIGN) is one of the most common causes of
acute glomerulonephritis in children. It may lead to inflammation and proliferation
of glomerular tissue through immunologic mechanisms (Balasubramanian R, Paediatr Int
Child Health 2017;37:240–247).
Ethnic representation analysis of commercial movie posters
Authors: Kagan Dima , Levy Mor , Fire Michael , Fuhrmann Alpert Galit
Published: February 2024

In the last decades, global awareness toward the importance of diverse representation has been increasing. The lack of diversity and discrimination toward minorities did not skip the film industry. Here, we examine ethnic bias in the film industry through commercial posters, the industry’s primary advertisement medium for decades. Movie posters are designed to establish the viewer’s initial impression. We developed a novel approach for evaluating ethnic bias in the film industry by analyzing nearly 125,000 posters using state-of-the-art deep learning models. Our analysis shows that while ethnic biases still exist, there is a trend of reduction of bias, as seen by several parameters. Particularly in English-speaking movies, the ethnic distribution of characters on posters from the last couple of years is reaching numbers that are approaching the actual ethnic composition of the US population. An automatic approach to monitoring ethnic diversity in the film industry, potentially integrated with financial value, may be of significant use for producers and policymakers.
The role of emotion and social connection during the COVID-19 pandemic phase transitions: a cross-cultural comparison of China and the United States
Authors: Lu Liangdong , Xu Jia , Wei Jiuchang , Shults F. LeRon , Feng Xing Lin
Published: February 2024

Leveraging substantial data from China’s Weibo and datasets from Reddit and X (previously Twitter) in the United States, this research explores the disparities and complex dynamics of emotions and social connections among social media users in China and the United States during the COVID-19 pandemic. The findings indicate that the expression of three negative emotions (anxiety, sadness, and anger) and positive emotions exhibited distinctive dynamics under the impact of the pandemic, with China individuals expressing more anxiety but less sadness and anger than those in the US. Moreover, Chinese social media experienced a surge in positive emotional expressions under lockdown, whereas the US witnessed a conspicuous decline in positive emotions. Also, the expression of three types of social connections - “family”, “collective”, and “country”-exhibited significant differences under the impact of the pandemic, with Chinese individuals establishing deeper connections with their country and American individuals leaning towards familial connections. Further analysis on the moderating effects of social connections substantiated that the “country” connection in China and the “family” connection in the US mitigated the negative emotions affected by the pandemic. These findings facilitate a deeper understanding of how cultural contexts shape social and psychological responses in crises. Based on topic analysis and forward-looking orientation analysis, this study dissects the aforementioned findings through the dichotomy of collectivist and individualist cultures, providing new insights for social psychological support and emotional guidance in the development of public health communication strategies in the future.
Taking inspiration from dolphins to develop drag-reducing surface structures
Authors: Thompson Avery
Published: February 2024

Understanding the effects of transverse ridges can lead to more efficient ships and underwater turbines.
Impact of ion-specific interactions on laser-induced liquid microjet generation
Authors: Rana Bhawna , Kamath Rakshith , Mishra Manoranjan , Jena Kailash C.
Published: February 2024

Jet velocity and jet power are the crucial parameters that govern the release profile of drugs/vaccines in needle-free injection systems, where salts are considered as one of the essential constituents of drugs/vaccines as adjuvants. However, the impact of salts on the generation of laser-induced liquid microjets that have shown tremendous potential for drug delivery has remained unexplored. Here, we have investigated the influence of Hofmeister ions on the velocity of laser-induced liquid jets in rhodamine 6G (Rh6G) dye solution. A comprehensive experimental approach is adopted to find out the values of the liquid microjet velocity by varying the parameters, such as input energy of the laser beam, concentrations of the dye, and specific Hofmeister ions in the aqueous solution. From our experimental findings, it is observed that the presence of ions significantly influences the jet velocity that follows the Hofmeister series: SO42−>I−>SCN−. This, in turn, governs the ion-specific penetration depth of liquid jets as simulated for the model soft tissues. The observed Hofmeister trend in the jet velocity values showcases the possible specific-ion interactions between anions and Rh6G molecules in the aqueous solution. Our detailed experimental findings on ion-specific jet velocity and jet power could be beneficial in designing needle-free drug delivery systems with controlled penetration depths.
Three-dimensional crescent-shaped ion velocity distributions created by magnetic reconnection in the presence of a guide field
Authors: Usami Shunsuke , Zenitani Seiji
Published: February 2024

By means of theory and particle simulations, crescent-shaped ion velocity distributions in the outflow region of symmetric magnetic reconnection in the presence of a guide magnetic field are investigated. Assuming a spatial one-dimensional electromagnetic field, a theoretical model accounting for the shape of crescents is derived. First, following the earlier theoretical models suggested by Bessho et al. [Geophys. Res. Lett. 43, 1828–1836 (2016)] and Zenitani et al. [J. Geophys. Res.: Space Phys. 122, 7396–7413 (2017)], we derive a theoretical model for 2D velocity distributions based on the conservation of the canonical momentum and the energy. The 2D theoretical model exhibits a two-dimensional structure of crescent-shaped velocity distributions and further demonstrates that no magnetic field reversal is required in the formation of crescents, although many researchers have considered that magnetic field reversal plays an essential role. Next, we construct a theoretical model for 3D velocity distributions based not only on the conservation of the canonical momentum in two directions and the energy but also on the conservation of the magnetic moment and the kinetic energy in the moving frame with the reconnection outflow speed, which are applied when the guide field ratio is high. The 3D theoretical model derives a three-dimensional structure of crescents by combination of an antiparallel magnetic field and a guide magnetic field comparable to or greater than the reconnection field. Both of the 2D and 3D theoretical models are consistent with ion velocity distributions found in our particle simulations.
Thermal expansion coefficient of ScN(111) thin films grown on Si(111) determined by X-ray diffraction
Authors: Ciprian L. , Mihalic S. , Lüttich C. , Hörich F. , Wade E. , Christian B. , Dadgar A. , Ambacher O.
Published: February 2024

Scandium nitride (ScN) has emerged as a promising material in various fields due to its exceptional characteristics, including high mechanical strength, hardness, high melting point, high thermal stability, and wide bandgap. This work investigates the thermal behavior of ScN by the measurement of its coefficient of linear thermal expansion (TEC). A (111)-oriented ScN thin film on a (111)-oriented Si substrate is used for the measurements. The lattice parameter is determined using x-ray diffraction, and in situ measurements are performed at elevated temperatures of up to 923 K. The expansion of the material with increasing temperature is modeled using Debye's phonon dispersion. The fitted lattice parameters are used to calculate the TEC, which we measured to be (6.61±0.60)×10−6 K−1 at 300 K. Thus, the value is 1.37×10−6 K−1 lower than the value published by Tahri et al. [J. Phys.: Condens. Matter 24, 035401 (2011)]. who simulated the TEC for a ScN bulk crystal. This work contributes to the knowledge on thermal properties of ScN and paves the way for further research in this field.
Sampling the reciprocal Coulomb potential in finite anisotropic cells
Authors: Schäfer Tobias , Van Benschoten William Z. , Shepherd James J. , Grüneis Andreas
Published: February 2024

We present a robust strategy to numerically sample the Coulomb potential in reciprocal space for periodic Born–von Karman cells of general shape. Our approach tackles two common issues of plane-wave based implementations of Coulomb integrals under periodic boundary conditions: the treatment of the singularity at the Brillouin-zone center and discretization errors, which can cause severe convergence problems in anisotropic cells, necessary for the calculation of low-dimensional systems. We apply our strategy to the Hartree–Fock and coupled cluster (CC) theories and discuss the consequences of different sampling strategies on different theories. We show that sampling the Coulomb potential via the widely used probe-charge Ewald method is unsuitable for CC calculations in anisotropic cells. To demonstrate the applicability of our developed approach, we study two representative, low-dimensional use cases: the infinite carbon chain, for which we report the first periodic CCSD(T) potential energy surface, and a surface slab of lithium hydride, for which we demonstrate the impact of different sampling strategies for calculating surface energies. We find that our Coulomb sampling strategy serves as a vital solution, addressing the critical need for improved accuracy in plane-wave based CC calculations for low-dimensional systems.
The field theory of collective Cherenkov radiation associated with electron beams
Authors: Schamiloglu Edl , Figotin Alexander
Published: February 2024

Classical Cherenkov radiation is a celebrated physics phenomenon of electromagnetic (EM) radiation stimulated by an electric charge moving with constant velocity in a three-dimensional dielectric medium. Cherenkov radiation has a wide spectrum and a particular distribution in space similar to the Mach cone created by a supersonic source. It is also characterized by the energy transfer from the charge's kinetic energy to the EM radiation. In the case of an electron beam passing through the middle of an EM waveguide, the radiation is manifested as collective Cherenkov radiation. In this case, the electron beam can be viewed as a one-dimensional non-neutral plasma, whereas the waveguide can be viewed as a slow wave structure. This collective radiation occurs, in particular, in traveling wave tubes (TWTs), and it features the energy transfer from the electron beam to the EM radiation in the waveguide. Based on a first principles Lagrangian field theory, we develop a convincing argument that the collective Cherenkov effect in TWTs is, in fact, a convective instability, that is, amplification. We also recover Pierce's theory as a high-frequency limit of our generalized Lagrangian theory. Finally, we derive for the first time expressions identifying low- and high-frequency cutoffs for amplification in TWTs.
Polarization-insensitive and polarization-controlled dual-band third-harmonic generation in silicon metasurfaces driven by quasi-bound states in the continuum
Authors: Qin Meng , Wei Gangao , Xu Hangsheng , Ma Ruize , Li Hongju , Gao Weiqing , Liu Jianqiang , Wu Feng
Published: February 2024

High-refractive-index nanostructures offer versatile opportunities for nonlinear optical effects, due to their ability to strongly confine field into a subwavelength scale. Herein, we propose a rhomboidal amorphous silicon metasurface to realize high-efficiency dual-band third-harmonic generation (THG), based on the supported dual quasi-bound states in the continuum (Q-BICs). Owing to the very large field confinement inside the metasurface empowered by Q-BICs, the THG efficiency up to 3.74 × 10−3 with the peak pump intensity of 30 MW/cm2 is observed. Meanwhile, thanks to the very high quality factor of Q-BICs, the ultra-narrow nonlinear process with the full width at half maximum less than 1 nm is also witnessed, suggesting the good monochromaticity. Interestingly, the dual-band THG is verified to be polarization-dependent and polarization-insensitive, respectively. The finite element method simulations exhibit that the polarization-dependent THG is attributed to the Q-BIC driven by the electric quadrupole characterized by a pair of anti-parallel electric dipoles along the x axis, which are only excited by the x-linearly polarized light. On the contrary, the polarization-insensitive THG is enabled by another Q-BIC governed by the magnetic dipole resonance with circular electric field vectors, which can be excited by any linearly polarized light. The polarization-controlled and polarization-independent dual-band THG enabled by the physics of Q-BICs would open possibilities for designing switchable nonlinear light sources. The proposed dual Q-BICs scheme undoubtedly can serve as a universal recipe for other nonlinear effects, including sum-frequency generation, difference-frequency generation, and high-order harmonics.
Limiting current on periodic electron sheets in a planar diode
Authors: Chernin David , Li Dion , Lau Y. Y.
Published: February 2024

We consider the steady-state limiting current that can be carried by an infinite periodic array of thin electron sheets spaced by period p in a planar diode of gap voltage V and gap separation d. Our primary assumptions are as follows: (1) electron motion is restricted by an infinite magnetic field to the direction normal to the electrode surfaces, (2) all electrons are emitted from the cathode with initial kinetic energy Ein, and (3) electron motion is non-relativistic. The limiting current density, averaged over a period and normalized to the classical 1D Child–Langmuir (CL) current density (including a factor that accounts for nonzero Ein), is found to depend only on the two dimensionless parameters p/d and Ein/eV. This average limiting current density is computed from the maximum current density for which the iterative solution of a non-linear integral equation converges. Numerical results and empirical curve fits for the limiting current are presented, together with an analysis as p/d and Ein/eV approach zero or infinity, in which cases previously published results are recovered. Our main finding is that, while the local anode current density within each electron sheet is infinite in our model (that is, it exceeds the classical 1D CL value by an “infinite” factor), the period average anode current density is in fact still bounded by the classical 1D CL value. This study therefore provides further evidence that the classical 1D Child–Langmuir current density is truly a fundamental limit that cannot be circumvented.
Isolated slug traveling in a voided line and impacting at an end orifice
Authors: He Junling , Hou Qingzhi , Yang Xuliang , Duan Huanfeng , Lin Lei
Published: February 2024

Driven by upstream high-pressure steam, liquid slugs in nuclear power plant pipelines impact the end orifice at high speed, leading to bursting pipelines and threatening the plant's safety. This research aimed to accurately and efficiently assess the dynamic behavior of an isolated slug driven by pressurized air in a voided line with an end orifice. An improved one-dimensional (1D) model for the slug motion and impact was established. The dynamic variation of the pressure at both the slug's tail and front, the variation of the slug length, and the frictional resistance coefficient in the model was obtained by three-dimensional (3D) computational fluid dynamics (CFD). Based on 27 cases with different pipeline diameters and tank pressures, it was observed that the driving air pressure had a quadratic relationship and that the slug length had a constant rate of decrease vs the slug tail displacement. Finally, the decrease in the driving air pressure behind the slug, the increase in the air pressure ahead of the slug, the holdup coefficient, and the friction factor obtained from the 3D CFD results were interpreted in the 1D model, and the velocity histories of the liquid slug were found to be in excellent agreement with the 3D CFD solutions.
Pendant drop motion and stability in vertical airflow
Authors: Dockery Jacob D. , Aydin Duygu Yilmaz , Dickerson Andrew K.
Published: February 2024

When exposed to an ascending flow, pendant drops oscillate at magnitudes determined by windspeed, drop diameter, and needle diameter. In this study, we investigate the retention stability and oscillations of pendant drops in a vertical wind tunnel. Oscillation is captured by a high-speed camera for a drop Reynolds number Re = 200–3000. Drops at Re ≲ 1000 oscillate up to 12 times the frequency of drops with high Re. Increasing windspeed enables larger volume drops to remain attached to the needles above Re = 500. We categorize drop dynamics into seven behavioral modes according to the plane of rotation and deformation of shape. Video frame aggregation permits the determination of a static, characteristic shape of our highly dynamic drops. Such a shape provides a hydraulic diameter and the evaluation of the volume swept by the oscillating drops with time. The maximum swept volume per unit drop volume occurs at Re = 600, corresponding to the peak in angular velocity.
Lagrangian dynamics of multiscale vortices in electromagnetically driven two-dimensional turbulence
Authors: Siao Chen-Yu , Lo Wei-Shuo , I Lin
Published: February 2024

We experimentally investigate the dynamics of decomposed multiscale vortex cores (VCs) as singular objects of the two-dimensional (2D) turbulence driven by the Lorentz force from a direct current electric field and 2D magnetic lattice array. It is found that, in the xyt space, VCs of each mode (i.e., vortex spatial scale) appear as a zoo of unstable wiggling filament arrays with spatially alternating signs of vorticities. VC interaction and the chaotic external Lorentz force for vorticity injection and retraction lead to: (a) the spatial bunching of the VCs of adjacent modes, and the decaying position correlation of VCs with their separation and increasing mode number; (b) single VC dissociation and VC pair recombination, and in turn stretched exponential distributions of VC lifetimes of all modes; (c) similar persistent (super) diffusions of VCs of all modes, associated with persistent changes of the mean square vorticity fluctuations of VCs of the corresponding modes; and (d) the positively correlated instantaneous energy (enstrophy) variations between two neighboring VCs of modes 3 (the scale of the magnetic array for external vorticity injection and retraction) and its harmonics mode 4, and two-way instantaneous energy (enstrophy) exchange of the flow field surrounding VCs of modes 1–2 and modes 2–3.
Experimental study on the cavity dynamics of a sphere entering flowing water
Authors: Wang Xu , Qi Chao , Liu Chen , Sun Ruisheng , Lyu Xujian
Published: February 2024

This paper delves into the dynamics of a sphere entering flowing water at varying impact velocities and flow speeds. Using a high-speed photography system and image processing, we track the cavity evolution and trajectory. Flowing water is observed to tilt the cavity and postpone its detachment from the free surface. Beyond surface sealing, we identify a flowing-induced pinch-off phenomenon during water entry, marking a transition in closure regimes. This transition establishes a threshold impacting cavity tilt angle and pull-away length. By mapping the phase diagram of flow Reynolds number (Rew) against impact Froude number (Fr), we classify partial surface seal, pinch-off, and surface seal into distinct regimes. The Fr1/3 law effectively predicts the rising trend of cavity depth (H) and pinch-off depth (Hp) in flowing water. However, the Hp/H ratio differs from that reported in existing literature.
Controlling the symmetry breaking charge transfer extent in excited quadrupolar molecules by tuning the locally excited state
Authors: Mikhailova Tatyana V. , Ivanov Anatoly I.
Published: February 2024

The effect of a locally excited state on charge transfer symmetry breaking (SBCT) in excited quadrupolar molecules in solutions has been studied. The interaction of a locally excited state and two zwitterionic states is found to either increase or decrease the degree of SBCT depending on the molecular parameters. A strategy on how to adjust the molecular parameters to control the extent of SBCT is presented. The influence of level degeneracy on SBCT is identified and discussed in detail. The level degeneracy is shown to lead to the existence of a hidden dipole moment in excited quadrupolar molecules. Its manifestations in SBCT are analyzed. The main conclusions are consistent with the available experimental data.
Exploring patterns of lexical variation in the use of epistemic stance markers in written L2 English across task types and levels of proficiency
Authors: Pyykönen Maria
Published: February 2024

The present study examines the lexical patterning of altogether 4,022 instances of epistemic stance markers (EDs)
across four levels of L2 proficiency (B1–C2) and three types of writing tasks (‘opinion’, ‘complaint’, and ‘letter’) by using the
exploratory technique of Multiple Correspondence Analysis. The data stem from a Finnish learner English corpus,
comprising of 1,773 texts. The results of the study showed that while the lexical patterns of EDs in the data seemed to be mostly
related to task type, some proficiency-related patterns of ED use were observed across all tasks. In some cases,
proficiency-related patterns could also only be observed in some of the tasks, suggesting task type and proficiency are, to some
extent, interrelated when examining the use of EDs. The results thus suggest that both task- and proficiency-related constraints
of EDs should be considered in both foreign language teaching and assessment.
Je dirais / diría yo, analyse contrastive français / espagnol
Authors: Vázquez-Molina Jesús , Donaire María Luisa
Published: February 2024

L’objectif de cette contribution est une étude contrastive de deux entités, je dirais en
français et diría yo en espagnol. La stratégie discursive instruite par le marqueur français je
dirais représente une certaine attitude du locuteur, celui-ci présentant un contenu p, dont il est
la source, comme non partagé par la communauté linguistique. Cette description sémantico-pragmatique trouve sa correspondance en
surface avec des propriétés formelles spécifiques, notamment la position en incise et la combinatoire avec certaines unités
linguistiques. Le marqueur de la langue espagnole admet les mêmes combinaisons que je dirais et présente
d’autres propriétés communes avec ce dernier. Malgré ces quelques ressemblances le comportement sémantico-pragmatique des
deux marqueurs diffère, je dirais mettant l’accent sur le dire, tandis que dans le cas de diría
yo l’accent est mis sur le dit.
“Wouldn’t it be better for me to earn my own money and pay taxes?”
Authors: Lampropoulou Sofia , Johnson Paige
Published: February 2024

This study concentrates on migrant representations in stories posted on the websites of UK charity
organizations. Drawing upon critical discourse analytic and narrative positioning tools, we examine migrant identity
navigation in the past and present that, predominantly, leads to the construction of fulfillment identities.
We discuss the ways in which these positionings promote an ideal migrant norm that contributes to wider national homogenizing
discourses. We view these stories as sites of liquid racism that divide migrants who succeed and are, thus,
fulfilled and migrants who are deviant. We interrogate these representations, given that
charity organizations are committed to providing social assistance to migrants and refugees, thus aligning with humanitarian
and antiracist discourses.
INPP4B ensures that ILC1s and NK cells set up a productive home office
Authors: Chen Zi Yan , Mortha Arthur
Published: February 2024

In this issue of JEM, Peng et al. (https://doi.org/10.1084/jem.20230124) identify inositol polyphosphate 4-phosphatase type II (encoded by Inpp4b) as an important enzyme for tissue-resident ILC1 and NK cell survival, signal transduction, and anti-tumor immunity.
Inverse problem for Love waves in a layered, elastic half-space
Authors: de Hoop Maarten V , Garnier Josselin , Iantchenko Alexei , Ricaud Julien
Published: February 2024

In this paper we study Love waves in a layered, elastic half-space. We first address the direct problem and we characterize the existence of Love waves through the dispersion relation. We then address the inverse problem and we show how to recover the parameters of the elastic medium from the empirical knowledge of the frequency–wavenumber couples of the Love waves.
Influence of temperature on bandgap shifts, optical properties and photovoltaic parameters of GaAs/AlAs and GaAs/AlSb p–n heterojunctions: insights from ab-initio DFT + NEGF studies
Authors: Mamindla Ramesh , Niranjan Manish K
Published: February 2024

The III–V group semiconductors are highly promising absorbers for heterojunctions based solar cell devices due to their high conversion efficiency. In this work, we explore the solar cell properties and the role of electron–phonon coupling (EPC) on the solar cell parameters of GaAs/AlSb and GaAs/AlAs p–n heterojunctions using non-equilibrium Green function method (NEGF) in combination of ab-initio density functional theory (DFT). In addition, the band offsets at the heterointerfaces, optical absorption and bandgap shifts (BGSs) due to temperature are estimated using DFT + NEGF approach. The interface band gaps in heterostructures are found to be lower than bulk band gaps leading to a shift in optical absorption coefficient towards lower energy side that results in stronger photocurrent. The temperature dependent electronic BGS is significantly influenced by the phonon density and phonon energy via EPC. The phonon influenced BGS is found to change the optical absorption, photocurrent density and open-circuit voltage. In case of GaAs/AlSb junction, the interface phonons are found to have significantly higher energies as compared to the bulk phonons and thereby may have important implications for photovoltaic (PV) properties. Overall, the present study reveals the influence of EPC on the optical absorption and PV properties of GaAs/AlSb and GaAs/AlSb p–n heterojunctions. Furthermore, the study shows that the DFT + NEGF method can be successfully used to obtain the reasonable quantitative estimates of temperature dependent BGSs, optical absorption and PV properties of p–n heterojunctions.
High-pressure induces topology boosting thermoelectric performance of Bi2Te3
Authors: Cheng Jiaen , Wang Fei , Lian Min , Wang Dianzhen , Wang Lu , You Cun , Wang Xinglin , Ge Yufei , Liang Xiao , Tao Qiang , Chen Yanli , Zhu Pinwen
Published: February 2024

Decoupling conductivity

(
σ
)

and Seebeck coefficient

(
S
)

by electronic topological transitions (ETT) under high pressure (2–4 GPa) is a promising method for bismuth telluride (Bi2Te3) to optimize thermoelectric (TE) performance. However, the

S

cannot dramatically increase with increasing

σ

when ETT occurs in Bi2Te3, which impedes optimizing TE performance by utilizing ETT in Bi2Te3. A new strategy of enhanced ETT by combining lattice distortions and high pressure is proposed in this work. The lattice distortions in Bi2Te3 were introduced by high pressure and high temperature (HPHT) treatment to generate surplus dislocations. The in-situ measurements of

σ

and

S

at HPHT in Bi2Te3 with lattice distortions show an enhanced ETT effect at 2 GPa, which causes decouple

σ

and

S

with an anomalous increase in its

|
S
|

about 22%. The ETT effect causes the figure of merit (

Z
T

) of Bi2Te3 can be improved to 0.275 at 1.50–2.62 GPa, 460 K, it is more than 62% compared with 0.79 GPa, at 450 K. The excellent TE performance of Bi2Te3 arising from the lattice distortions can result in local non-hydrostatic pressure which enhances ETT under high pressure. This work provides a new strategy to enhance ETT to decouple

σ

and

S

, and search for better TE materials from the pressure dimension in the future.