bluuebunny/crossref_metadata_2025 huggingface dataset:
Concordance of Frozen Section Diagnosis of Epithelial Ovarian Neoplasm and Discussing the Diagnostic Pitfalls: An Institutional Experience
Authors: Sharma Jagannath D. , Kakoti Lopa M. , Ahmed Shiraj , Sarma Anupam , Barman Debabrat
Published: March 2023

Background Ovarian neoplasm is the third most common malignancy in Indian women. Intraoperative diagnosis becomes the critical guiding tool for the surgeons to take the decisions on the extent of surgery specially when preserving fertility has to be considered.

Aims and Objective The aim of this study is to evaluate the concordance of intraoperative diagnosis of frozen section (IFS) of ovarian epithelial neoplasm at our institute and to review and discuss the diagnostic pitfalls along with the review of literature.

Materials and Methods Data were archived from departmental record and the detailed clinical data of the patients were retrieved from hospital record system. The discordant cases were reviewed again in an attempt to address the pitfalls.

Statistical Analysis Diagnostic accuracy, sensitivity, specificity, and positive and negative predictive value of IFS of ovarian neoplasm were analyzed.

Results The overall frozen section diagnosis was concordant with final histopathology in 36 out of 44 cases (81%). The sensitivity of IFS diagnosis was found to be 100% for benign and borderline tumors, whereas 88.9% for malignant epithelial tumors, but the correctness of diagnosis is high only for benign and malignant tumors (high positive predictive value) in compared with borderline ones. The diagnostic pitfalls were identified individually in discordant cases.

Conclusion An accurate interpretation of IFS in ovarian epithelial malignancy can be achieved in benign and malignant cases, but limited in borderline tumors. Awareness of the artifacts and the limitations in mind and the IFS diagnosis can be of great help for proper management of the ovarian neoplasm.
Marching Ahead through the Pandemic: Continuing Anesthesia Services in COVID Era—Our Experience from a Tertiary Care Cancer Centre
Authors: Bhan Swati , Gupta Raghav , Vig Saurabh , Garg Rakesh , Gupta Nishkarsh , Kumar Vinod , Bharati Sachidanand Jee , Mishra Seema , Ratre Brajesh , Pandit Anuja , Sirohiya Prashant , Singh Ram , Kumar Balbir , Bhopale Shweta , Bhatnagar Sushma
Published: March 2023

Introduction This paper aims to provide an overview of the administrative and clinical preparations done in a tertiary care cancer hospital in continuing operation theatre (OT) services through the COVID pandemic.

Methods Retrospective data collection, data for the past 1.5 years (COVID period) March 2020 to August 2021 were compared to surgical output for a similar duration of time before the COVID era (September 2018–February 2020).

Results A total of 1,022 surgeries were done under anesthesia in the COVID period as against 1,710 surgeries done in a similar time frame in the pre-COVID era. Overall, we saw a 40%drop in the total number of cases. Thorax, abdominal, and miscellaneous surgeries (soft tissue sarcomas, urology, and gyneconcology) saw a maximum fall in numbers; however, head and neck cases saw an increase in numbers during the pandemic. Surgical morbidity and mortality were similar in the COVID and pre-COVID era. No cases of severe COVID infection were reported among the healthcare staff working in OT.

Discussion We could successfully continue our anesthesia services with minimal risk to healthcare staff throughout the pandemic by adopting major guidelines in a pragmatic and practical approach with minor changes to suit our setup.
Everolimus as a therapeutic option in refractory epilepsy in children with tuberous sclerosis: a systematic review
Authors: Menezes Catarina Ester Gomes , Santos Débora Lopes dos , Nery Erick Santos , Serpa Evelin Duarte , Morais Lécio Aragão Souza , Dutra Lucas Santana , Portela Filho Marcos Baruch , Goes Julieta Sobreira
Published: March 2023

Background Tuberous sclerosis (TS) is a multisystem genetic disease in which epilepsy is a frequent manifestation and is often difficult to control. Everolimus is a drug with proven efficacy in the treatment of other conditions related to TS, and some evidence suggests that its use benefits the treatment of refractory epilepsy in these patients.

Objective To evaluate the efficacy of everolimus in controlling refractory epilepsy in children with TS.

Methods A literature review was conducted in the Pubmed, BVS, and Medline databases, using the descriptors Tuberous sclerosis, Children, Epilepsy, and Everolimus. Original clinical trials and prospective studies published in Portuguese or English in the last decade that evaluated the use of everolimus as an adjuvant therapy in the control of refractory epilepsy in pediatric patients with TS were included.

Results Our search screened 246 articles from electronic databases, 6 of which were chosen for review. Despite the methodological variations between the studies, most patients benefited from the use of everolimus to control refractory epilepsy, with response rates ranging from 28.6 to 100%. Adverse effects were present in all studies leading to dropouts of some patients; however, the majority were of low severity.

Conclusion The selected studies suggest a beneficial effect of everolimus in the treatment of refractory epilepsy in children with TS, despite the adverse effects observed. Further studies involving a larger sample in double-blind controlled clinical trials should be performed to provide more information and statistical credibility.
BRAF V600E Mutations and Beyond: A Molecular Perspective of Melanoma from a Tertiary Cancer Referral Center of India
Authors: Vengurlekar Vaibhavi , Shetty Omshree , Gurav Mamta , Bapat Prachi , Karnik Nupur , Wagh Gauri , Epari Sridhar , Rekhi Bharat , Ramadwar Mukta , Desai Sangeeta
Published: March 2023

Objectives Malignant melanoma demonstrates frequently occurring mutations of genes in the serine/threonine kinase pathway, namely BRAF, NRAS, and neurofibromin 1. There is rare documentation of a detailed analysis of these mutations in cases of melanoma among Indian patients. We present molecular features in cases of malignant melanoma, diagnosed at a tertiary cancer referral center in India, over a period of 8 years (2011–2018).

Materials and Methods This study was performed on formalin fixed paraffin embedded tissues of 88 histologically confirmed cases of malignant melanoma. BRAF gene alterations were studied by both Sanger sequencing and real-time polymerase chain reaction techniques (n = 74). Molecular testing for BRAF and NRAS gene alterations was accomplished in 74/88 cases (80%). Molecular test results were correlated with clinicopathological features using IBM SPSS Statistical software 25.0.

Results The age ranged from 13 to 79 years (median = 57), with a M:F ratio of 1.4:1. BRAF mutations were observed in 12/74 (16.21%) patients, including V600E (n = 7), A594T (n = 1), T599 = (n = 2), V600K (n = 1), and Q612P (n = 1), while NRAS mutations were observed in 6/38 (15.7%) patients. Among various subtypes, nodular melanoma was the most frequent subtype (33%) among cutaneous malignant melanomas. Among non-cutaneous melanomas, mucosal melanomas were observed in 37.5% of cases.

Conclusion This constitutes one of the few reports on comprehensive analysis of molecular alterations underlying melanomas in Indian patients. A larger sample size, with more extensive molecular markers, would yield additional information on the disease manifestation.
Axial Skeleton Bone Marrow Changes in Inflammatory Rheumatologic Disorders
Authors: Reijnierse Monique
Published: March 2023

Magnetic resonance imaging (MRI) of the axial skeleton, spine, and sacroiliac (SI) joints is critical for the early detection and follow-up of inflammatory rheumatologic disorders such as axial spondyloarthritis, rheumatoid arthritis, and SAPHO/CRMO (synovitis, acne, pustulosis, hyperostosis, and osteitis/chronic recurrent multifocal osteomyelitis). To offer a valuable report to the referring physician, disease-specific knowledge is essential. Certain MRI parameters can help the radiologist provide an early diagnosis and lead to effective treatment. Awareness of these hallmarks may help avoid misdiagnosis and unnecessary biopsies. A bone marrow edema-like signal plays an important role in reports but is not disease specific. Age, sex, and history should be considered in interpreting MRI to prevent overdiagnosis of rheumatologic disease. Differential diagnoses—degenerative disk disease, infection, and crystal arthropathy—are addressed here. Whole-body MRI may be helpful in diagnosing SAPHO/CRMO.
The Many Faces of Marrow Necrosis
Authors: Mourad Charbel , Omoumi Patrick , Vande Berg Bruno
Published: March 2023

Depending on the age and location within the skeleton, bone marrow can be mostly fatty or hematopoietic, and both types can be affected by marrow necrosis. This review article highlights the magnetic resonance imaging findings of disorders in which marrow necrosis is the dominant feature.

Fatty marrow necrosis is detected on T1-weighted images that show an early and specific finding: the reactive interface. Collapse is a frequent complication of epiphyseal necrosis and detected on fat-suppressed fluid-sensitive sequences or using conventional radiographs. Nonfatty marrow necrosis is less frequently diagnosed. It is poorly visible on T1-weighted images, and it is detected on fat-suppressed fluid-sensitive images or by the lack of enhancement after contrast injection.

Pathologies historically “misnamed” as osteonecrosis but do not share the same histologic or imaging features of marrow necrosis are also highlighted.
Sex-Related Differences in Patient Characteristics, Risk Factors, and Symptomatology in Older Adults with Pulmonary Embolism: Findings from the SERIOUS-PE Study
Authors: Bikdeli Behnood , Muriel Alfonso , Wang Yun , Piazza Gregory , Khairani Candrika D. , Rosovsky Rachel P. , Mehdipoor Ghazaleh , O'Donoghue Michelle L. , Madridano Olga , Lopez-Saez Juan Bosco , Mellado Meritxell , Brasero Ana Maria Diaz , Grandone Elvira , Spagnolo Primavera A. , Lu Yuan , Bertoletti Laurent , López-Jiménez Luciano , Núñez Manuel Jesús , Blanco-Molina Ángeles , Gerhard-Herman Marie , Goldhaber Samuel Z. , Bates Shannon M. , Jimenez David , Krumholz Harlan M. , Monreal Manuel ,   The RIETE Investigators
Published: March 2023

Sex-specific factors are implicated in pulmonary embolism (PE) presentation in young patients, as indicated by increased risk in pregnancy. Whether sex differences exist in PE presentation, comorbidities, and symptomatology in older adults, the age group in which most PEs occur, remains unknown. We identified older adults (aged ≥65 years) with PE in a large international PE registry replete with information about relevant clinical characteristics (RIETE registry, 2001–2021). To provide national data from the United States, we assessed sex differences in clinical characteristics and risk factors of Medicare beneficiaries with PE (2001–2019). The majority of older adults with PE in RIETE (19,294/33,462, 57.7%) and in the Medicare database (551,492/948,823, 58.7%) were women. Compared with men, women with PE less frequently had atherosclerotic diseases, lung disease, cancer, or unprovoked PE, but more frequently had varicose veins, depression, prolonged immobility, or history of hormonal therapy (p < 0.001 for all). Women less often presented with chest pain (37.3 vs. 40.6%) or hemoptysis (2.4 vs. 5.6%) but more often with dyspnea (84.6 vs. 80.9%) (p < 0.001 for all). Measures of clot burden, PE risk stratification, and use of imaging modalities were comparable between women and men. PE is more common in elderly women than in men. Cancer and cardiovascular disease are more common in men, whereas transient provoking factors including trauma, immobility, or hormone therapy are more common in elderly women with PE. Whether such differences correlate with disparities in treatment or differences in short- or long-term clinical outcomes warrants further investigation.
Adaptability of electron-localization strategy for achieving planar tetracoordination: Nitrogen versus carbon
Authors: Jia Xiu-dong , Bian Jian-hong , Jin Bo , Sun Rui , Huo Bin , Guan Xiao-ling , Guo Chenfei , Yuan Caixia , Wu Yan-bo
Published: March 2023

A case study has been performed on the adaptability of electron-localization strategy in designing clusters with planar tetracoordinate nitrogen (ptN) through the detailed comparison between ptN clusters NLi3E+ (E=N, P, As) and their planar tetracoordinate carbon (ptC) counterparts CLi3E (E=N, P, As). The results revealed that NLi3E+ clusters possessed similar planar geometries to CLi3E, which are both determined by the existence of a localized π bond. Nevertheless, NLi3E+ clusters possess the obviously higher electronic, thermodynamic, and dynamic stabilities than CLi3E clusters, as reflected by wider HOMO-LUMO gaps (4.58-4.68 eV versus 2.10–2.74 eV), the overall lower-lying positions on potential energy surfaces verified at the CCSD(T)/aug-cc-pVTZ level, and better rigidity during the molecular dynamic simulations at the PBE/DZVP level. Therefore, our results suggest that electron-localization strategy may be more suitable for designing the clusters, whose central atom possesses relatively higher electronegativity and more favours the localized bond. Due to the good stability, the cationic NLi3E+ clusters designed in this work may be suitable for gas phase generation, mass-selection, and spectroscopic characterization.
A Martin–Puplett interferometer (MPI) optical polarimeter: Design and laboratory tests
Authors: Zhang Yapeng , Liu Zhengdong , Xing Chunqing , Sun Wei , Zhong Jiayong
Published: March 2023

Spontaneous and external magnetic fields interacting with plasmas are essential in high-energy-density and magnetic confinement fusion physics. Measuring these magnetic fields, especially their topologies, is crucial. This paper develops a new type of optical polarimeter based on the Martin–Puplett interferometer (MPI), which can probe magnetic fields with the Faraday rotation method. We introduce the design and working principle of an MPI polarimeter. With the laboratory tests, we demonstrate the measurement process and compare the results with the measurement result of a Gauss meter. These very close results verify the polarization detection capability of the MPI polarimeter and show the potential for its application in magnetic field measurement.
Theoretical model of radiation heat wave in two-dimensional cylinder with sleeve
Authors: Xiao Cheng-Jian , Meng Guang-Wei , Zhao Ying-Kui
Published: March 2023

A semi-analytical model is constructed to investigate two-dimensional radiation heat waves (Marshak waves) in a low-Z foam cylinder with a sleeve made of high-Z material. In this model, the energy loss to the high-Z wall is regarded as the primary two-dimensional effect and is taken into account via an indirect approach in which the energy loss is subtracted from the drive source and the wall loss is ignored. The interdependent Marshak waves in the low-Z foam and high-Z wall are used to estimate the energy loss. The energies and the heat front position calculated using the model under typical inertial confinement fusion conditions are verified by simulations. The validated model provides a theoretical tool for studying two-dimensional Marshak waves and should be helpful in providing further understanding of radiation transport.
Temporal evolution of pressure profiles for laser-induced cavitation bubble on the metal surface
Authors: Hironaka Y. , Shigemori K. , Ozaki N. , Kurita T. , Kodama R.
Published: March 2023

When a laser is focused on an underwater object, it experiences a large amount of pressure owing to the plasma confinement effect of water. A hemispherical bubble is generated on the surface of the object, and large pressure is generated when the bubble collapses. In this study, we conducted experiments using different laser energies to analyze the pressure–time histories associated with bubble contraction. The maximum pressure was 10%–40% of the laser ablation pressure, whereas the pressure pulse width was 5–10 times longer than the laser pulse width. Furthermore, the bubble motion could be adiabatically explained, except for the plasma interaction region. The results indicate that the pressure at which the bubble collapses does not depend on the maximum size of the generated bubble but depends on the energy of water vapor within the bubble.
Noise-driven bursting birhythmicity in the Hindmarsh–Rose neuron model
Authors: Slepukhina Evdokiia , Bashkirtseva Irina , Kügler Philipp , Ryashko Lev
Published: March 2023

The stochastic Hindmarsh–Rose model is studied in the parameter region where two bursting limit cycles of different types coexist. We show that under the influence of noise, transitions between basins of attractions appear, which generates stochastic bursting oscillations of mixed modes. The formation of this new regime is accompanied by anti-coherence and coherence resonances as well as by the transition to chaos. We investigate the probabilistic mechanism of the noise-driven bursting birhythmicity using the stochastic sensitivity functions and confidence domains method.
Binary coalescence of non-Newtonian droplets under an electric field: A numerical study
Authors: Mandal Joy , Chatterjee Deep , Sarkar Sandip
Published: March 2023

We numerically investigate the effect of electrohydrodynamics on a non-Newtonian droplet pair suspended in a Newtonian medium. The leaky dielectric model is implemented to study the response of emulsion drops in an externally applied electric field. Subsequently, the non-Newtonian drop behavior is incorporated using the power law model, whereby three different fluid behaviors are considered for the drops: Newtonian, Shear thinning, and Shear thickening. We validated our numerical model with the available literature data, and the results are in good agreement. The droplets' deformation and net motion are investigated for a range of electrical permittivity ratios of the droplet medium with respect to the surrounding fluid. In this study, four distinct regimes are identified based on the net drop pair motion and the circulation pattern that develops due to the electric stresses inside and around the drops. Furthermore, it is observed that the droplet deformation and their net motion are fastest for the pseudo-plastic drops and slowest for dilatant drops. We devised a simple ratio-based model to understand this behavior. The inferences drawn from this study will help contribute to a better understanding of the behavior of nonlinear fluids under an electric field.
Theoretical study on the magnetic properties of cathode materials in the lithium–ion battery
Authors: Zhang Huimin , Zhong Yang , Ouyang Chuying , Gong Xingao , Xiang Hongjun
Published: March 2023

The layered LiMO2 (M = Co, Ni, and Mn) materials are commonly used as the cathode materials in the lithium–ion battery due to the distinctive layer structure for lithium extraction and insertion. Although their electrochemical properties have been extensively studied, the structural and magnetic properties of LiNiO2 are still under considerable debate, and the magnetic properties of monoclinic LiMnO2 are seldom reported. In this work, a detailed study of LiNiO2, LiMnO2, and a half-doped material LiNi0.5Mn0.5O2 is performed via both first-principles calculations and Monte Carlo simulations based on the effective spin Hamiltonian model. Through considering different structures, it is verified that a structure with a zigzag-type pattern is the most stable one of LiNiO2. Moreover, in order to figure out the magnetic properties, the spin exchange interactions are calculated, and then magnetic ground states are predicted in these three systems. The results show that LiNiO2 forms a spiral order that is caused by the competition from both the short-range and long-range spin exchange interactions, whereas the magnetic ground state of LiMnO2 is collinearly antiferromagnetic due to its nearest and next-nearest neighbor antiferromagnetic spin exchange interactions. However, LiNi0.5Mn0.5O2 is collinearly ferrimagnetic because of the ferromagnetic nearest neighbor Ni–Ni and Mn–Mn exchange interactions. Our work demonstrates the competition between the different exchange interactions in these cathode materials, which may be relevant to the performance of the lithium–ion battery.
Transition from chimera/solitary states to traveling waves
Authors: Rybalova E. , Muni S. , Strelkova G.
Published: March 2023

We study numerically the spatiotemporal dynamics in a ring network of nonlocally coupled nonlinear oscillators, each represented by a two-dimensional discrete-time model of the classical van der Pol oscillator. It is shown that the discretized oscillator exhibits richer behavior, combining the peculiarities of both the original system and its own dynamics. Moreover, a large variety of spatiotemporal structures is observed in the network of discrete van der Pol oscillators when the discretization parameter and the coupling strength are varied. Regimes, such as the coexistence of a multichimera state/a traveling wave and a solitary state are revealed for the first time and are studied in detail. It is established that the majority of the observed chimera/solitary states, including the newly found ones, are transient toward a purely traveling wave mode. The peculiarities of the transition process and the lifetime (transient duration) of the chimera structures and the solitary state are analyzed depending on the system parameters, the observation time, initial conditions, and the influence of external noise.
Synthesis and characterization of metal carbides for nanoindentation tip applications
Authors: Boatner L. A. , Finch C. B. , Brundage W. E. , Kolopus J. A. , Gruzalski G. R. , Johanns K. E. , Sudharshan Phani P. , Pharr G. M. , Oliver W. C.
Published: March 2023

Instrumented indentation experiments at elevated temperatures require careful attention to a myriad of experimental details. Not the least of these is the choice of the indenter tip material. Traditional room-temperature indenters, e.g., diamond and sapphire, can break down, react, and wear excessively at elevated temperatures. In this work, rf-induction heating float-zone and high-temperature solution single-crystal growth techniques have been used to prepare a suite of bulk refractory carbide specimens (i.e., ZrC, VC0.86, NbC, TiC0.95, WC). These potential indenter tip materials were subsequently characterized using nanoindentation testing techniques to determine their single-crystal elastic modulus, hardness, and fracture toughness in order to evaluate their potential for use as elevated-temperature nanoindentation tips. Additionally, subject carbide crystal characteristics were compared to those of single-crystal sapphire and polycrystalline WC-Co. The cumulative results show that single-crystal WC is a promising candidate for indenter tip material based on a combination of its high elastic modulus, hardness, and resistance to cracking—in addition to being crystallographically favorable for fabrication in the frequently used three-sided pyramidal indenter tip geometries.
Fully epitaxial, monolithic ScAlN/AlGaN/GaN ferroelectric HEMT
Authors: Wang Ding , Wang Ping , He Minming , Liu Jiangnan , Mondal Shubham , Hu Mingtao , Wang Danhao , Wu Yuanpeng , Ma Tao , Mi Zetian
Published: March 2023

In this Letter, we demonstrated fully epitaxial ScAlN/AlGaN/GaN based ferroelectric high electron mobility transistors (HEMTs). Clean and atomically sharp heterostructure interfaces were obtained by utilizing molecular beam epitaxy. The fabricated ferroelectric gate HEMTs showed counterclockwise hysteretic transfer curves with a wide threshold voltage tuning range of 3.8 V, a large ON/OFF ratio of 3 × 107, and reconfigurable output characteristics depending on the poling conditions. The high quality ferroelectric gate stack and effective ferroelectric polarization coupling lead to improved subthreshold performance, with subthreshold swing values approaching 110 and 30 mV/dec under forward and backward gate sweeps, respectively. The results provide fundamental insight into the ferroelectric polarization coupling and threshold tuning processes in ferroelectric nitride heterostructures and are promising for nitride-based nonvolatile, multi-functional, reconfigurable power, and radio frequency devices as well as memory devices and negative capacitance transistors for next-generation electronics.
Leveraging neural differential equations and adaptive delayed feedback to detect unstable periodic orbits based on irregularly sampled time series
Authors: Zhu Qunxi , Li Xin , Lin Wei
Published: March 2023

Detecting unstable periodic orbits (UPOs) based solely on time series is an essential data-driven problem, attracting a great deal of attention and arousing numerous efforts, in nonlinear sciences. Previous efforts and their developed algorithms, though falling into a category of model-free methodology, dealt with the time series mostly with a regular sampling rate. Here, we develop a data-driven and model-free framework for detecting UPOs in chaotic systems using the irregularly sampled time series. This framework articulates the neural differential equations (NDEs), a recently developed and powerful machine learning technique, with the adaptive delayed feedback (ADF) technique. Since the NDEs own the exceptional capability of accurate reconstruction of chaotic systems based on the observational time series with irregular sampling rates, UPOs detection in this scenario could be enhanced by an integration of the NDEs and the ADF technique. We demonstrate the effectiveness of the articulated framework on representative examples.
A multifaceted poverty reduction program has economic and behavioral consequences
Authors: Li Wenchao , Leng Zhiming , Yi Junjian , Zhong Songfa
Published: March 2023

This paper examines the causal impact of poverty reduction interventions on the social preferences of the poor. A multifaceted poverty reduction program in China provides a setting for the use of a fuzzy regression discontinuity design. The design compares households with base-year income just below a preset criterion, who were more likely to receive the program treatment, with households just above the criterion. Five years after the program’s launch, we conducted a lab-in-the-field experiment to measure the distributional preferences of household heads. Combining quasi-random variation from program rules with administrative census and experimental data, we find both economic and behavioral consequences of the program: It increased household income by 50% 5 y later, increased consistency with utility maximization by household heads, and increased their efficiency preference while reducing selfishness and leaving equality preference unchanged. Our findings advance scientific understanding of social preferences formation and highlight a broad perspective in evaluating poverty reduction interventions.
Landau theory for finite-time dynamical phase transitions
Authors: Meibohm Jan , Esposito Massimiliano
Published: March 2023

We study the time evolution of thermodynamic observables that characterise the dissipative nature of thermal relaxation after an instantaneous temperature quench. Combining tools from stochastic thermodynamics and large-deviation theory, we develop a powerful theory for computing the large-deviation statistics of such observables. Our method naturally leads to a description in terms of a dynamical Landau theory, a versatile tool for the analysis of finite-time dynamical phase transitions. The topology of the associated Landau potential allows for an unambiguous identification of the dynamical order parameter and of the phase diagram. As an immediate application of our method, we show that the probability distribution of the heat exchanged between a mean-field spin model and the environment exhibits a singular point, a kink, caused by a finite-time dynamical phase transition. Using our Landau theory, we conduct a detailed study of the phase transition. Although the manifestation of the new transition is similar to that of a previously found finite-time transition in the magnetisation, the properties and the dynamical origins of the two turn out to be very different.
Gate reflectometry in dense quantum dot arrays
Authors: Ansaloni Fabio , Bohuslavskyi Heorhii , Fedele Federico , Rasmussen Torbjørn , Brovang Bertram , Berritta Fabrizio , Heskes Amber , Li Jing , Hutin Louis , Venitucci Benjamin , Bertrand Benoit , Vinet Maud , Niquet Yann-Michel , Chatterjee Anasua , Kuemmeth Ferdinand
Published: March 2023

Silicon quantum devices are maturing from academic single- and two-qubit devices to industrially-fabricated dense quantum-dot (QD) arrays, increasing operational complexity and the need for better pulsed-gate and readout techniques. We perform gate-voltage pulsing and gate-based reflectometry measurements on a dense 2 × 2 array of silicon QDs fabricated in a 300 mm-wafer foundry. Utilizing the strong capacitive couplings within the array, it is sufficient to monitor only one gate electrode via high-frequency reflectometry to establish single-electron occupation in each of the four dots and to detect single-electron movements with high bandwidth. A global top-gate electrode adjusts the overall tunneling times, while linear combinations of side-gate voltages yield detailed charge stability diagrams. To test for spin physics and Pauli spin blockade at finite magnetic fields, we implement symmetric gate-voltage pulses that directly reveal bidirectional interdot charge relaxation as a function of the detuning between two dots. Charge sensing within the array can be established without the involvement of adjacent electron reservoirs, important for scaling such split-gate devices towards longer 2 × N arrays. Our techniques may find use in the scaling of few-dot spin-qubit devices to large-scale quantum processors.
Modelling chromosome-wide target search
Authors: Hedström Lucas , Lizana Ludvig
Published: March 2023

The most common gene regulation mechanism is when a transcription factor (TF) protein binds to a regulatory sequence to increase or decrease RNA transcription. However, TFs face two main challenges when searching for these sequences. First, the sequences are vanishingly short relative to the genome length. Second, there are many nearly identical sequences scattered across the genome, causing proteins to suspend the search. But as pointed out in a computational study of LacI regulation in Escherichia coli, such almost-targets may lower search times if considering DNA looping. In this paper, we explore if this also occurs over chromosome-wide distances. To this end, we developed a cross-scale computational framework that combines established facilitated-diffusion models for basepair-level search and a network model capturing chromosome-wide leaps. To make our model realistic, we used Hi-C data sets as a proxy for 3D proximity between long-ranged DNA segments and binding profiles for more than 100 TFs. Using our cross-scale model, we found that median search times to individual targets critically depend on a network metric combining node strength (sum of link weights) and local dissociation rates. Also, by randomizing these rates, we found that some actual 3D target configurations stand out as considerably faster or slower than their random counterparts. This finding hints that chromosomes’ 3D structure funnels essential TFs to relevant DNA regions.
A plasma chemistry model for H2/SiH4 mixtures used in PECVD processes
Authors: Sushkov Vladimir , Rachdi Lazhar , Hofmann Marc
Published: March 2023

Plasma chemical processes in H2/SiH4 discharges are critically reviewed. A model set of reactions is proposed which includes temperature and pressure-dependent reaction rates and describes SiyHx (y ≤ 3) chemistry. Using a 2D fluid plasma simulator, the model has been tested under three different set of operating conditions. First, it has been validated against the experimental benchmark data (Horvath and Gallagher (2009) J. Appl. Phys.
105, 13304). Based on considerations of atomic hydrogen content, the branching of SiH4 dissociation channels and the H surface loss probability have been defined more accurately. Then, simulations have been also performed for the plasma source of a PECVD tool from Meyer Burger Germany. A very good agreement between the computed and experimentally determined deposition rates can be stated.
The instability analysis of self-gravitation systems under the perturbation with orbital angular momentum
Authors: Yang Qiaoyun , Tan Ling , Chen Hui , Liu Sanqiu
Published: March 2023

Based on plasma kinetic theory, the instabilities of self-gravitation systems under perturbation with orbital angular momentum (OAM) are investigated, and the concept of twisted Jeans mode is introduced to describe the new phenomenon. The result shows that the growth rate of the Jeans instability is enhanced with the OAM parameter increased, while the critical wave number is consistent with the classical Jeans critical value. It is expected that the present results would give more insight into the evolution and dynamics of a self-gravitational system.
An ultrafast spectroscopy system for studying dynamic properties of superconductors under high pressure and low temperature conditions
Authors: Zhu Jian , Li Ye-Xi , Feng Deng-Man , Su De-Peng , Fan Dong-Niu , Yang Song , Zhao Chen-Xiao , Zhao Gao-Yang , Li Liang , Li Fang-Fei , Wang Ying-Hui , Zhou Qiang
Published: March 2023

An ultrafast pump-probe spectroscopy system combined with a cryogenic diamond anvil cell (DAC) instrument is developed to investigate the photo-excitation dynamic properties of condensed materials under low temperature and high pressure (LTHP) conditions. The ultrafast dynamics study is performed on Bi2Sr2CaCu2O8+δ
(Bi-2212) thin film under LTHP conditions. The superconducting (SC) phase transition has been observed by analyzing the ultrafast dynamics of Bi-2212 as a function of pressure and temperature. Our results suggest that the pump-probe spectroscopy system combined with a cryogenic DAC instrument is an effective method to study the physical mechanism of condensed matter physics at extreme conditions, especially for the SC phase transition.
A novel fractional-order hyperchaotic complex system and its synchronization
Authors: Jin Mengxin , Sun Kehui , He Shaobo
Published: March 2023

A novel fractional-order hyperchaotic complex system is proposed by introducing the Caputo fractional-order derivative operator and a constant term to the complex simplified Lorenz system. The proposed system has different numbers of equilibria for different ranges of parameters. The dynamics of the proposed system is investigated by means of phase portraits, Lyapunov exponents, bifurcation diagrams, and basins of attraction. The results show abundant dynamical characteristics. Particularly, the phenomena of extreme multistability as well as hidden attractors are discovered. In addition, the complex generalized projective synchronization is implemented between two fractional-order hyperchaotic complex systems with different fractional orders. Based on the fractional Lyapunov stability theorem, the synchronization controllers are designed, and the theoretical results are verified and demonstrated by numerical simulations. It lays the foundation for practical applications of the proposed system.
Orientation determination of nitrogen-vacancy center in diamond using a static magnetic field
Authors: Wang Yangpeng , Zhang Rujian , Yang Yan , Wu Qin , Yu Zhifei , Chen Bing
Published: March 2023

Nitrogen-vacancy (NV) centers in a bulk diamond are often employed to realize measurement of multiple physical quantities, which depends on orientation information of NV axis. We report a fast and effective method to determine the orientation of NV axis with the aid of a static magnetic field. By measuring the optically detected magnetic resonance spectra, we can precisely extract the polar angle information between the NV axis and the known magnetic field. Combining with the polar angle information of different kinds of NV centers, we employ the Nelder–Mead algorithm to get the optimal solution of the orientation of NV axis. This method is simple and efficient, and is easily applied in NV-based quantum sensing.
Entanglement properties of superconducting qubits coupled to a semi-infinite transmission line
Authors: Guo Yang-Qing , Chen Ping-Xing , Li Jian
Published: March 2023

Quantum entanglement, a key resource in quantum information processing, is reduced by interaction between the quantum system concerned and its unavoidable noisy environment. Therefore it is of particular importance to study the dynamical properties of entanglement in open quantum systems. In this work, we mainly focus on two qubits coupled to an adjustable environment, namely a semi-infinite transmission line. The two qubits’ relaxations, through individual channels or collective channel or both, can be adjusted by the qubits’ transition frequencies. We examine entanglement dynamics in this model system with initial Werner state, and show that the phenomena of entanglement sudden death and revival can be observed. Due to the hardness of preparing the Werner state experimentally, we introduce a new type of entangled state called pseudo-Werner state, which preserves as much entangling property as the Werner state, and more importantly, it is experiment friendly. Furthermore, we provide detailed procedures for generating pseudo-Werner state and studying entanglement dynamics with it, which can be straightforwardly implemented in a superconducting waveguide quantum electrodynamics system.
Gauging universe expansion via scalar fields
Authors: Kumar Devanarayanan Rajeeb , Pathak S.D. , Ojha Vikash Kumar
Published: March 2023

In this study, we investigate the expansion of the FRLW universe in the open, closed, and flat geometries. The universe is dominated by a scalar field (spatially homogeneous) as a source of dark energy. We consider the three different classes of scalar fields – quintessence, tachyonic, and phantom field – for our analysis. A mathematical analysis is carried out by considering these three scalar fields with exponential and power-law potentials. Both potentials give exponential expansion in the open, closed, and flat FRLW universes. It is found that quintessence, tachyonic, and phantom scalar fields are indistinguishable under the slow roll approximation.
Investigation on the Formation of Herringbone Structure in Type II Solar Radio Bursts
Authors: Abidin Z. Z. , Zulkiplee A. N. , Epin V. , Pauzi F. A. M.
Published: March 2023

We report detailed observation of the “herringbone” of a Type II solar radio burst that occurred on 2010 November 3rd. Data from the Space Weather Prediction Center, National Oceanic and Atmospheric Administration, e-CALLISTO, and Nançay RadioHeliograph are analyzed. We determine the brightness temperature and degree of circular polarization of the “herringbone” burst. Correlations between the physical parameters and the “herringbone” are examined. Based on the relationship, this is the first study that suggested this “herringbone” was generated through fundamental plasma.
New Photometric Investigations of G-type Contact Binary TU Boo
Authors: Wang Jing-jing , Guo Meng , Jiang Lin-qiao , Zhang Bin
Published: March 2023

Two sets of CCD photometric observations for contact binary TU Boo were obtained in 2020 and 2021. Different from its asymmetric light curves published from the literature, our BVR

c

I

c
-band curves show that the heights of maximum are almost equal. These distortions of light curves possibly indicate that the components were active in past 25 yr, but they were stable in the last two years. For total-eclipse binary TU Boo, due to some star-spots on the surface of the components, the physical structure obtained by many investigators are different. Therefore, the symmetric multi-color light curves in 2020, 2021 are important for understanding configuration and evolution of this system. By using the Wilson–Devinney program, it is confirmed that TU Boo is an A-type shallow-contact binary with the temperature difference of ΔT = 152 K and fill-out of f = 14.67%. In the O−C diagram of orbital period analysis, a cyclic oscillation superimposed on a continuous decrease was determined. The long-term decreasing is often explained by the mass transfer from the more massive star to less massive one, this system will evolve into a deeper contact binary with time. The cyclic oscillations computed from much more CCD times of light minimum maybe result from the light-travel time effect via the presence of a third body. These characters of structure, evolution and ternary belong to typical A-type W UMa binaries with spectral G.
Constraints on Dark Energy from the CSST Galaxy Clusters
Authors: Zhang Yufei , Chen Mingjing , Wen Zhonglue , Fang Wenjuan
Published: March 2023

We study the potential of the galaxy cluster sample expected from the Chinese Space Station Telescope (CSST) survey to constrain dark energy properties. By modeling the distribution of observed cluster mass for a given true mass to be log-normal and adopting a selection threshold in the observed mass M
200m
≥ 0.836 × 1014
h
−1
M
⊙, we find about 4.1 × 105 clusters in the redshift range 0 ≤ z ≤ 1.5 can be detected by the CSST. We construct the Fisher matrix for the cluster number counts from CSST, and forecast constraints on dark energy parameters for models with constant (w
0CDM) and time dependent (w
0
w

a
CDM) equation of state. In the self-calibration scheme, the dark energy equation of state parameter w
0 of the w
0CDM model can be constrained to Δw
0 = 0.036. If w

a
is added as a free parameter, we obtain Δw
0 = 0.077 and Δw

a
= 0.39 for the w
0
w

a
CDM model, with a Figure of Merit for (w
0, w

a
) of 68.99. Should we have perfect knowledge of the observable-mass scaling relation (“known SR” scheme), we would obtain Δw
0 = 0.012 for the w
0CDM model, and Δw
0 = 0.062 and Δw

a
= 0.24 for the w
0
w

a
CDM model. The dark energy Figure of Merit of (w
0, w

a
) increases to 343.25. This indicates again the importance of calibrating the observable-mass scaling relation for optically selected galaxy clusters. By extending the maximum redshift of the clusters from

z

max

∼
1.5

to

z

max

∼
2

, the dark energy Figure of Merit for (w
0, w

a
) increases to 89.72 (self-calibration scheme) and 610.97 (“known SR” scheme), improved by a factor of ∼1.30 and ∼1.78, respectively. We find that the impact of clusters’ redshift uncertainty on the dark energy constraints is negligible as long as the redshift error of clusters is smaller than 0.01, achievable by CSST. We also find that the bias in logarithm mass must be calibrated to be 0.30 or better to avoid significant dark energy parameter bias.
Electrostatic turbulence in EAST plasmas with internal transport barrier
Authors: Ma Yuehao , Zhang Bin , Bao Jian , Lin Z. , Zhang Wenlu , Cai Huishan , Li Ding
Published: March 2023

Based on first-principles nonlinear gyrokinetic simulations, the electrostatic turbulence properties in the internal transport barrier (ITB) region of an Experimental Advanced Superconducting Tokamak discharge (#93890) are investigated. Specifically, ITBs with steep density and temperature gradients are located in the weakly negative magnetic shear region at the plasma center. In the linear stage, the growth rate and frequency of the ion temperature gradient (ITG) mode increase significantly due to resonant excitation by trapped electrons. That is, the resonance between trapped electrons and the ITG becomes strong due to the precession drift reversal of trapped electrons by the negative magnetic shear and Shafranov shift. Meanwhile, the trapped electron mode is stable in the ITB region due to only a very small fraction of electrons precessing in the direction of the electron diamagnetic drift. Nonlinear simulations show that, after considering the non-adiabatic effect of trapped electrons, the heat conductivity of ions and the turbulence intensity increase by at least a factor of 7 compared with the results only considering the adiabatic effect of electrons. The zonal charge density of trapped electrons can partially cancel that of ions, which weakens the intensity of the zonal flow, and consequently reduces the zonal flow regulation and enhances the turbulent transport.
Comment on ‘Backflow in relativistic wave equations’
Authors: Bracken A J , Melloy G F
Published: March 2023

Criticisms and a claim in the recent paper Backflow in relativistic wave equations by Bialynicki–Birula et al 2022 J. Phys. A: Math. Theor.
55 255702 are addressed, and it is emphasized again that the widely discussed phenomenon of quantum probability backflow has no classical counterpart. It is pointed out that backflow for the relativistic Dirac Equation has been treated in depth by us some years ago and by others since.
Reply to comments on ‘Backflow in relativistic wave equations’
Authors: Bialynicki-Birula Iwo , Bialynicka-Birula Zofia , Augustynowicz Szymon
Published: March 2023

We present further arguments which show that the backflow has a universal character. It is not restricted to quantum theory and it appears in many theories (quantum or classical). It is a general property of waves propagating in any number of dimensions.
Curved surface measurement method using chromatic confocal sensor and tilt scanning
Authors: Wan Yifu , Guo Tong , Wu Sen , An Xinyu
Published: March 2023

Large measurement ranges and curvature changes are characteristics of curved surfaces, making it difficult to measure their topography. In this study, a four-axis measurement system is developed, and a tilt scanning measurement method using a chromatic confocal sensor is proposed to measure curved surfaces. The measurement area is divided into different parts, in which the tilt scanning measurement is performed with different angles of the chromatic confocal sensor. After the scanning, the complete measurement data are restored by data processing and stitching. Compared with conventional scanning methods, the proposed method greatly expands the measurement range. Finally, the effectiveness of the developed measurement system and the tilt scanning measurement method is clearly verified by measuring a spherical specimen with a radius of 50 mm.
New evaluation method for the characterization of coatings by electroerosive alloying
Authors: Zhengchuan Zhang , Tarelnyk Viacheslav , Konoplianchenko Ievgen , Guanjun Liu , Hongyue Wang , Xin Du , Yao Ju , Zongxi Li
Published: March 2023

The running-in coatings were formed on the surface of tin bronze QSn10-1 by electroerosive alloying (EEA) with soft antifriction materials such as silver, copper, Babbitt B83 and graphene oxide (GO). The mass transfer, surface roughness, coating thickness and dry friction coefficient of the running-in coatings were measured and analyzed by a precision electronic balance, three-dimensional optical profiler, metallographic microscope, scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and friction and wear tester. An evaluation indicator system for the characterization was constructed based on six factors, including material price, time, mass transfer, roughness, thickness and friction coefficient of the coatings by electroerosive alloying. The Shannon entropy method was used to calculate the weight of different indices, and a comprehensive evaluation method for running-in coatings performance was proposed by combining the technique for order preference by similarity to ideal solution (TOPSIS) and a multicriteria decision-making technique. The TOPSIS model was employed for the comprehensive evaluation ranking of the characterization of the running-in coatings by electroerosive alloying.