bluuebunny/crossref_metadata_2025 huggingface dataset:
De Quervain's Tenosynovitis Treated with Homoeopathy: A Case Report
Authors: Chakma Abhijit , Khadim Azizul I. , Shail Vivek K.
Published: October 2024

De Quervain's tenosynovitis (DQT) is a painful inflammatory condition that mainly affects the thumb and the radial side of the wrist joint. Homeopathy is frequently used successfully in daily practice to treat such conditions. Therefore, there is a need for well-documented case reports that illustrate its usefulness. This case report describes the successful management of DQT with individualized homeopathic medicine. A 45-year-old male, employed as an auto driver, had been experiencing pain on the radial side of his right wrist joint for three years. Based on an individualized assessment, Mercurius solubilis was prescribed in increasing potencies (200, 1M). There was a significant improvement in the symptoms within four months of treatment. Pain and limitations in function were assessed using a Visual Analog Scale in each visit, and the patient's mental well-being was evaluated monthly using the nine-item Patient Health Questionnaire. The response to homeopathic treatment was also assessed using the Modified Naranjo Criteria for Homeopathy-causal attribution inventory, shedding further light on the role of individualized medicine in homeopathy. This case report suggests that a correctly chosen homeopathic medicine can be beneficial in the treatment of DQT in a relatively short period of time.
Top 10 Clinical Pearls in Paraproteinemic Neuropathies
Authors: Becker Benjamin , Stino Amro
Published: October 2024

Paraproteinemic neuropathies represent an important subset of peripheral neuropathies. Once identified, further evaluation into the paraproteinemic subtype, clinical exam pattern, and electrodiagnostic phenotype helps clarify if the paraproteinemia is coincidental or causal of the neuropathy, as not all paraproteinemias cause neuropathy. Of all paraproteinemias, immunoglobulin M (IgM)-associated peripheral neuropathy, or IgM neuropathy, is of particular importance as half of IgM neuropathies also harbor anti-myelin-associated glycoprotein antibodies, which produce a characteristic demyelinating pattern on nerve conduction testing. Immunoglobulin G and immunoglobulin A paraproteinemias are less strongly associated with peripheral neuropathy, except in the setting of multiple myeloma or osteosclerotic myeloma (POEMS syndrome), which have characteristic systemic features. In multiple myeloma, chemotherapy is more likely to result in neuropathy than the myeloma itself. Finally, the presence of systemic features (e.g., cardiomyopathy, nephropathy, recurrent carpal tunnel syndrome, and autonomic insufficiency) should raise concern for hereditary or acquired light (AL) chain amyloidosis. AL amyloidosis can occur in the setting of any light or heavy chain paraproteinemia. Central to the proper evaluation of paraproteinemic neuropathy is electrodiagnostic testing, which helps delineate axonal versus demyelinating paraproteinemic neuropathy, the latter often misdiagnosed as chronic inflammatory demyelinating polyradiculoneuropathy.
The Role of GERD Diagnosis and Treatment in Preventing Lung Function Decline After Pediatric Lung Transplantation
Authors: Garrisi Elena Chiara , Müller Carsten , Ure Benno , Carlens Julia , Dingemann Jens , Schukfeh Nagoud
Published: October 2024

Background/Purpose Gastroesophageal reflux disease (GERD) after lung transplantation (LuTx) can lead to chronic lung allograft dysfunction. Our aim was to assess the prevalence of GERD in pediatric LuTx recipients and to investigate the impact of medical and surgical GERD treatment on lung function.

Methods Ethical approval was obtained. Data of all consecutive patients who underwent LuTx from 2013 to 2023 and aged < 18 years at the time of the study were prospectively collected. A GERD diagnostic algorithm was established, including assessment of symptoms (vomiting, heartburn, regurgitation, cough, recurrent airway infections), bronchoscopy, forced expiratory volume in 1 second, and pH impedance. Further investigations included upper gastrointestinal series and esophagogastroduodenoscopy. Patients with GERD underwent medical treatment or fundoplication. Lung function was monitored.

Results Thirty-six patients (2 months–18 years, 50% male) were included. Twenty-nine (80%) underwent spirometry, 16 (45%) pH impedance study, and 14 (39%) esophagogastroduodenoscopy. Twenty-two (61%) had no GERD symptoms and 12 (33%) showed normal pH impedance study or esophagogastroduodenoscopy. Fourteen (39%) patients had GERD symptoms, all 9 tested symptomatic patients (25%) had pathological GERD-specific diagnostics. Three (8%) patients underwent fundoplication after a median of 1.6 years (range 1.1–5.7 years) post-LuTx without surgical complications. After a median follow-up of 2.3 years (range 1.3–2.8 years) post-fundoplication, all (n = 3) had complete remission of GERD symptoms and lung function improvement. Lung function decline was observed in 6 (67%) of the tested symptomatic patients on proton-pump inhibitors (PPIs) treatment.

Conclusion Over one-third of our patients presented with GERD symptoms after LuTx. Symptoms and lung function may be reliable GERD indicators. Given the high prevalence of GERD, we suggest a routine posttransplant diagnostic algorithm including pH impedance study. Eighty percent of all symptomatic patients had a lung function decline despite PPI. Fundoplication is safe and may improve long-term outcome in pediatric LuTx recipients.
Hamiltonian structure of the guiding-center Vlasov–Maxwell equations with polarization and magnetization
Authors: Brizard Alain J.
Published: October 2024

The Hamiltonian formulation of guiding-center Vlasov–Maxwell equations, which contain dipole contributions to the guiding-center polarization and magnetization, is presented in terms of a guiding-center Hamiltonian functional that is derived from the exact guiding-center Vlasov–Maxwell energy conservation law, and an antisymmetric functional bracket that satisfies the Jacobi property. Exact energy-momentum and angular momentum conservation laws are expressed in the Hamiltonian form, and the guiding-center Vlasov–Maxwell entropy functional is shown to be a Casimir functional.
Polariton-assisted incoherent to coherent excitation energy transfer between colloidal nanocrystal quantum dots
Authors: Peng Kaiyue , Rabani Eran
Published: October 2024

We explore the dynamics of energy transfer between two nanocrystal quantum dots placed within an optical microcavity. By adjusting the coupling strength between the cavity photon mode and the quantum dots, we have the capacity to fine-tune the effective coupling between the donor and acceptor. Introducing a non-adiabatic parameter, γ, governed by the coupling to the cavity mode, we demonstrate the system’s capability to shift from the overdamped Förster regime (γ ≪ 1) to an underdamped coherent regime (γ ≫ 1). In the latter regime, characterized by swift energy transfer rates, the dynamics are influenced by decoherence time. To illustrate this, we study the exciton energy transfer dynamics between two closely positioned CdSe/CdS core/shell quantum dots with sizes and separations relevant to experimental conditions. Employing an atomistic approach, we calculate the excitonic level arrangement, exciton–phonon interactions, and transition dipole moments of the quantum dots within the microcavity. These parameters are then utilized to define a model Hamiltonian. Subsequently, we apply a generalized non-Markovian quantum Redfield equation to delineate the dynamics within the polaritonic framework.
A rapid compression large-volume press with a high pressure jump above 10 GPa within milliseconds
Authors: Hu Kuo , Liu Ran , Liu Shucheng , Feng Bingtao , Wang Saisai , Yao Di , Hou Xuyuan , Li Hongyu , Zhou Qiang , Liu Zhaodong , Liu Bingbing
Published: October 2024

A high pressure jump through a rapid compression within milliseconds (ms) provides an important approach for searching novel matters and investigating their physical and chemical properties. Herein, we report a unique rapid-compression large volume press with a high pressure jump above 10 GPa within 20 ms by introducing a Walker-type module and hydraulic accumulators. The sample pressure can be rapidly increased from 1–5 GPa to 12–16 GPa by different modest compression rates varying from 10−2 to 633.5 GPa/s. The rapid pressure jump on the specimen has been successfully verified through the observed rapid phase transition of ZnTe from semiconductor to metal transitions, as evidenced by the variation in its electrical conductivity. The highest pressure jump of 10.2 GPa within a rise time of 16.1 ms is achieved, which is significantly higher than previous results (5.8 GPa within 20 ms) using a Bridgman-type anvils in such an apparatus. We found that rapid compression significantly enhances the phase transformation of C70 fullerene from a disordered graphite to an amorphous phase compared to static high-pressure experiments. The high pressure jump technique developed in this study will thus have great applications in materials science, physics, chemistry, and earth science.
(010) β-(Alx, Ga1−x)2O3 growth using tritertiarybutylaluminum as Al gas precursor via hybrid molecular beam epitaxy
Authors: Wen Zhuoqun , Zhai Xin , Khan Kamruzzaman , Odabasi Oguz , Kim Mijung , Ahmadi Elaheh
Published: October 2024

We report the epitaxial growth of (010) β-(AlxGa1−x)2O3 using tritertiarybutylaluminum (TTBAl) as an aluminum gas precursor in a hybrid molecular beam epitaxy (h-MBE) system. In conventional MBE systems, a thermal effusion cell is typically used to supply Al. However, in an oxide MBE system, using a conventional Al effusion cell can cause difficulties due to the oxidation of the Al source during growth. This often requires breaking the vacuum frequently to reload Al. Our approach utilizes TTBAl, a gaseous Al source, via a h-MBE to circumvent the oxidation issues associated with traditional solid Al sources. We investigated the growth conditions of β-(AlxGa1−x)2O3, varying TTBAl supply and growth temperature. For this purpose, we utilized both elemental Ga and Ga-suboxide as Ga precursors. Controllable and repeatable growth of β-(AlxGa1−x)2O3 with Al compositions ranging from 1% to 25% was achieved. The impurity incorporation and crystal quality of the resulting β-(AlxGa1−x)2O3 films were also studied. Using TTBAl as a gaseous precursor in h-MBE has proven to maintain stable Al supply, enabling the controlled growth of high-quality β-(AlxGa1−x)2O3 films.
Experimental study on the high-speed water entry of cylinders at shallow angles
Authors: Guo Zeqing , Yan Xuepu , Sun Shuai , Liu Rushi , Zhu Mo , Huo Bingzhang , Zhao Longfei , Fang Ke
Published: October 2024

In this paper, high-speed photography was employed to experimentally study the high-speed, shallow-angle water entry of cylinders. By varying the density, length–diameter ratio, and launch speed of the cylinders, three typical trajectories were observed: arc, S, and ricochet trajectories. This study examined the cavity evolution, motion trajectory, force state, and stability of the cylinders under these three typical trajectories. Additionally, the influence of each cylinder's length–diameter ratio and density on the stability of its motion during shallow-angle water entry was explored. The experimental results indicated that during the impact stage, the cylinder generates a head-down torque, resulting in an upward deflection after entry. The combination of head force and angle of attack generates lift, which increases with a positive angle of attack. Consequently, the cylinder's deflection speed accelerates, while it slows with a negative angle of attack. During the tail-slap process, the combined forces from the head and tail both generate lift, but in the opposite directions. The motion stability decreases sequentially in the arc, S, and ricochet trajectories, which is closely related to the first tail-slap. Increasing the cylinder length–diameter ratio or density delays the occurrence of the first tail-slap, thereby enhancing motion stability during shallow-angle water entry.
Analytical model and experimental validation of critical dependency of pGaN gated AlGaN/GaN enhancement-mode high electron mobility transistor characteristics on trap-assisted tunneling
Authors: Jeyakumar Ranie S. , James J. J. , Ganguly Swaroop , Saha Dipankar
Published: October 2024

Enhancement-mode GaN-based high electron mobility transistors are essential for switching applications in power electronics. A heavily Mg-doped pGaN region is a critical feature of these devices. It pulls the Fermi energy level toward its valence band, depleting the two-dimensional electron gas region at the AlGaN/GaN interface at equilibrium. While a step profile of Mg doping in the pGaN region is desirable, it is difficult to achieve due to the out-diffusion of Mg-dopants, and the barrier AlGaN layer becomes unintentionally p-doped. This p-doping primarily leads to traps in the AlGaN barrier, leading to gate current through trap-assisted tunneling (TAT) and degradation of mobility due to the diffusion of the Mg-dopants to the channel region. The contribution of holes in the channel region and mobility degradation on the transistor characteristics are well understood. Here, we report the effect of TAT, which requires an improved understanding as it determines the key gate characteristics and transistor behavior. An increased TAT current increases the gate current and degrades the sub-threshold slope, which deteriorates transistor characteristics. However, TAT current makes the surface potential less sensitive to the change in gate voltage in the subthreshold regime, resulting in an increased transistor threshold voltage. Hence, an increase in the threshold voltage from the TAT current improves the fail-safe operation required for power-electronic applications. We show that the gate current and threshold voltage need to be tuned together for the desired performance of the enhancement-mode transistors.
Unsteady separation mechanism of ground horizontal-sliding takeoff system
Authors: Qian Hongjun , Wang Wenjie , Jiang Yi , Yan Peize , Cai Yunlong
Published: October 2024

Complex aerodynamic interference has long posed challenges to the safe separation of multi-body systems. Based on a new conceptual ground horizontal-sliding takeoff approach, the rocket sled system, computational fluid dynamics (CFD) simulations are conducted to study the separation between the payload and the rocket booster, with the Advisory Group for Aerospace Research and Development Model B representing the payload. The motion trajectory of the payload and the unsteady interaction flow mechanisms during separation are analyzed by altering the payload's layout, center of gravity (CoG), and sliding Mach number. The results show that positioning the payload closer to the front along the axis increases the likelihood of collisions after separation. At a sliding velocity of Ma=3, the payload tends to exhibit a nose-down attitude when lc/lp<0.64. Conversely, when lc/lp>0.64, the pitching angle becomes excessively large, which increases the risk of stalling or somersaulting. Furthermore, the CoG needs to move forward to reduce the growth rate of the pitching angle when the separation Mach number is increased. These studies can provide valuable references for the development of separation technology for the rocket sled system.
Thermal and flow characteristics of a Double-paths V ribbed U channel
Authors: Guo Xinxin , Li Xueying , Ren Jing
Published: October 2024

Higher thermal efficiency of gas turbines needs higher turbine inlet temperature, which is a challenge for temperature tolerance of turbine blades. Therefore, it is vital to propose and investigate advanced internal cooling structures. In this study, a Double-paths V ribbed U channel for rotating blade cooling is proposed and researched through heat transfer experiments of transient liquid crystal and flow simulations of Reynolds-averaging Navier–Stokes approaches in the conditions of Reynolds number (Re) at 16 000 and Rotation number (Ro) at 0, 0.006, and 0.024. The definition of the Double-paths V ribbed U channel is that it is a rotating U channel arranged from blade pressure side to suction side and that there are double passages from the pressure side to suction side from the cross section view of the blade. The novelties of the study are to reveal the interactions of V rib-induced, bend-induced, and Coriolis force-induced vortices and to unveil the heat transfer distributions and enhancement mechanisms with various Ro. Besides, the thermal and flow characteristics between the Double-paths V ribbed U channel and Double-paths 45° ribbed U channel are comparatively investigated as well. The results manifest that with identical pumping power, the Double-paths V ribbed U channel can achieve ascending heat transfer improvement as Ro rises owing to exploiting the positive heat transfer influence of Coriolis force on the pressure and suction sides, indicating that the channel is an inspiring and promising rotating structure applied for rotor blade internal cooling.
Integrating an urban fire model into an operational wildland fire model to simulate one dimensional wildland–urban interface fires: a parametric study
Authors: Purnomo Dwi M. J. , Qin Yiren , Theodori Maria , Zamanialaei Maryam , Lautenberger Chris , Trouvé Arnaud , Gollner Michael J.
Published: October 2024

Background Wildland fires that occur near communities, in the wildland–urban interface (WUI), can inflict significant damage to urban structures. Although computational models are vital in wildfires, they often focus solely on wildland landscapes. Aim We conducted a computational study to investigate WUI fire spread, encompassing both urban and wildland landscapes. Methods We developed a 1D landscape-scale semi-physical model by integrating a semi-physical urban fire spread model into an Eulerian level set model of wildfire. The model includes ignition and spread through radiation, direct flame contact and ember deposition. Key results Through a parametric study, we compare the relative change of spread rate from various structural properties and landscape layouts represented by model parameters, highlighting the significant impact of fire-resistant structure materials over surface treatments. Layout configurations play a pivotal role in fire spread, with isolated islands of combustibles effective in reducing spread rate, aligning with existing mitigation strategies. Conclusion Despite using a 1D domain and limitations on spatial and temporal variability, our model provides insights into underlying phenomena observed in WUI fires and their mitigation. It offers early-stage development of strategies for managing structure materials and landscape layouts. Implications Our model and findings provide insights into WUI fire dynamics, paving the way for advanced mitigation strategies.
Nuclear p62 condensates stabilize the promyelocytic leukemia nuclear bodies by sequestering their ubiquitin ligase RNF4
Authors: Fu Afu , Luo Zhiwen , Ziv Tamar , Bi Xinyu , Lulu-Shimron Chen , Cohen-Kaplan Victoria , Ciechanover Aaron
Published: October 2024

Liquid–liquid phase separation has emerged as a crucial mechanism driving the formation of membraneless biomolecular condensates, which play important roles in numerous cellular processes. These condensates, found both in the nucleus and cytoplasm, are formed through multivalent, low-affinity interactions between various molecules. P62-containing condensates serve, among other functions, as proteolytic hubs for the ubiquitin–proteasome system. In this study, we investigated the dynamic interplay between nuclear p62 condensates and promyelocytic nuclear bodies (PML-NBs). We show that p62 condensates stabilize PML-NBs under both basal conditions and following exposure to arsenic trioxide which stimulates their degradation. We further show that this effect on the stability of PML-NBs is due to sequestration of their ubiquitin E3 ligase RNF4 in the p62 condensates with subsequent rapid degradation of the ligase. The sequestration of the ligase is made possible by association between the proline-rich domain of the PML protein and the PB1 domain of p62, which results in the formation of a PML-NB shell around the p62 condensates. Importantly, these hybrid structures do not undergo fusion and mixing of their contents which leaves unsolved the mechanism of sequestration of RNF4 in the condensates. These findings suggest an additional possible mechanism of PML-NB as a tumor suppressor which is mediated via interactions between different biomolecular condensates.
Media as processes of doing and perceiving
Authors: Ladewig Silva H. , Horst Dorothea
Published: October 2024

The paper puts forward an integrated perspective on how meaning emerges in communicative media
contexts. We bring together linguistics and film studies to show how semiotic resources interact with their situated
media context. To ground our conceptual argument, we bring into dialogue Jan-Georg Schneider’s processual
understanding of media as procedures with Sybille Krämer’s media-philosophical view on media and Helmuth Plessner’s
philosophical anthropological thinking of human behavior. Using the example of a yoga tutorial that teaches the
cross-legged seat, we illustrate that the bodily experiences which are central to adopting the pose are mediated
through the interplay of multimodal metaphors and the qualitatively felt staging of the video. As a result, media turn
out as processes in which deliberate meaning-making and non-discursive sense-making go hand in hand.
The choreography of multimedial procedures and multimodal languaging
in French family dinners
Authors: Morgenstern Aliyah
Published: October 2024

In this paper we present a multimodal multimedial approach to multiparty interactions through the
analysis of French family dinners in which child and adult participants are engaged in the activities of eating and
interacting. The term multimodality is used to refer to the variety of semiotic resources (gesture, speech, facial
expressions, gaze) engaged in languaging (Linell 2009), and
multimediality to refer to the media used in context to construct meaning (such as communicative manipulative
actions/languaging). Our aim is to capture the multiple deployments of the embodied behaviors of
dinner participants, and children’s progressive socialization to multiactivity. We show how family members
collaboratively manage the accomplishments of multiple streams of activity and coordinate their temporal organizations
through the embodied performances of eating and interacting (Goodwin 1984).
The families consist of two adults and one to three children. We illustrate how children are progressively socialized
to the art of dining which involves food consumption and conversation. They learn to deploy multimedial procedures in
a multitude of skillful variations in the collective coordination of bodies, activities and artifacts.
Handling signs medially
Authors: Dang-Anh Mark
Published: October 2024

The mediality of linguistic signs is crucial to the understanding and analysis of language usage
and the construction of meaning since language in use is always materially mediated. By raising the following
fundamental questions from a semiopraxeological perspective, this paper seeks to make a theoretical and
methodological, yet empirically grounded, contribution to media linguistics. How do semiotic, medial, and social
aspects of practices relate to each other? How are materialised linguistic signs involved in the practical mediation
of sociality and, thus, culture? How can historical data be used to trace and analyse semiotic media practices? I
argue that, in addition to mediality, indexicality plays an essential role in answering these questions, and propose a
triadic model of semiotic media practices. This argument is illustrated using prisoner files from the U.S.
interrogation camp Fort Hunt during WWII.
Sharing Opportunistic Observations of Insects Provides Value for Pest Monitoring and Management in North America
Authors: Manning Paul , Jackson Morgan , Manning Ian
Published: October 2024

iNaturalist and other technology-enabled biodiversity recording applications allow individuals to easily capture and share biodiversity data. Built in machine-learning algorithms facilitate initial identification of the observed taxon, which is subsequently refined, corrected, or validated by the community of users. With hundreds of millions of records in iNaturalist alone, there is enormous potential to use this data for understanding where species occur in space and time. Insects (including species that can act as pests) are a commonly observed taxon within these databases. Numerous end-users are finding ways to effectively use this data to study and better understand pest insects. Here, we share three case studies that demonstrate the power of community-science data from iNaturalist in advancing science. We argue that in order to maintain a sustainable system of community science to serve these purposes, the following conditions must be met: excellent user-experience of the technology must be upheld, a welcoming and supportive atmosphere is maintained within the community of users, and that the efforts of contributors are formally recognized.

Information

© The Authors 2024
A video summary of the COLUMBUS 7 year update
Authors: Robert Caroline , Arance Ana , Mandalà Mario , Krajsová Ivana , Schadendorf Dirk , Gogas Helen J , Dummer Reinhard , de Groot Jan Willem B , Gutzmer Ralf , Liszkay Gabriella , Loquai Carmen , Garbe Claus , di Pietro Alessandra , Guenzel Carolin , Polli Anna , Queirolo Paola , Ascierto Paolo A
Published: October 2024

This video presents the COLUMBUS 7-year update on the efficacy of encorafenib plus binimetinib in the treatment of BRAF V600E/K-mutant melanoma.
The lifespan and kinetics of human dendritic cell subsets and their precursors in health and inflammation
Authors: Lubin Ruth , Patel Amit A. , Mackerodt Jonas , Zhang Yan , Gvili Rotem , Mulder Kevin , Dutertre Charles-Antoine , Jalali Parinaaz , Glanville James R.W. , Hazan Idit , Sridharan Nikhila , Rivkin Gurion , Akarca Ayse , Marafioti Teresa , Gilroy Derek W. , Kandel Leonid , Mildner Alexander , Wilensky Asaf , Asquith Becca , Ginhoux Florent , Macallan Derek , Yona Simon
Published: October 2024

Dendritic cells (DC) are specialized mononuclear phagocytes that link innate and adaptive immunity. They comprise two principal subsets: plasmacytoid DC (pDC) and conventional DC (cDC). Understanding the generation, differentiation, and migration of cDC is critical for immune homeostasis. Through human in vivo deuterium-glucose labeling, we observed the rapid appearance of AXL+ Siglec6+ DC (ASDC) in the bloodstream. ASDC circulate for ∼2.16 days, while cDC1 and DC2 circulate for ∼1.32 and ∼2.20 days, respectively, upon release from the bone marrow. Interestingly, DC3, a cDC subset that shares several similarities with monocytes, exhibits a labeling profile closely resembling that of DC2. In a human in vivo model of cutaneous inflammation, ASDC were recruited to the inflammatory site, displaying a distinctive effector signature. Taken together, these results quantify the ephemeral circulating lifespan of human cDC and propose functions of cDC and their precursors that are rapidly recruited to sites of inflammation.
Interplay between magnetisation dynamics and structure in MnCoGe thin films
Authors: Dolocan V O , Assaf E , Pilone O , Patout L , Charaï A , Hoummada K , Bertoglio M , Portavoce A , Bertaina S
Published: October 2024

We investigated the relation between magnetisation dynamics and microstructure in magnetocaloric MnCoGe thin films grown on two different substrates (Si or Ge). All the films show a hexagonal structure at room temperature, being polycrystalline when grown on Si substrates or displaying highly textured columnar grains with same orientation when grown on Ge substrates. Their static and dynamic magnetic properties present anomalies at lower temperature, with pronounced or singular features observed only for the highly textured samples : a significant modification of the magnetisation dynamics, as a large decoherence of the uniform resonance mode measured by ferromagnetic resonance (FMR) is found between 200 K and 10 K, when the magnetic field is applied normal to the surface, pointing to a spin order transition or a distorted structure with a canted spin arrangement. Below a freezing temperature, typical features of spin-glass like non-equilibrium dynamics are noted in the magnetic relaxation and memory effects suggesting magnetic frustration and disorder. In addition, the in-plane angular dependence of the resonance field displays a partial transition from the hexagonal phase below 200 K that can be attributed to the distortion of the hexagonal lattice with a canted spin arrangement observed in doped samples. The FMR linewidth increases strongly in this temperature range indicating a high magnetic damping, which is equally observed for the samples grown on Si below 40 K.
Measuring inverse flexoelectric effect at the macro scale and flexoelectric actuator
Authors: Lv Sihao , Li Zhaoqi , Shen Shengping
Published: October 2024

The flexoelectric effect is a two-way mechanical-electrical coupling. The dielectric is polarized when subjected to bending moments, and inversely, the electric field can also induce strain gradients within the dielectric. Although equally important, research on the inverse flexoelectric effect has lagged far behind that on the direct effect, and investigations of the inverse effect on a macroscopic scale are noticeably lacking. This dilemma impedes the design of flexoelectric actuators. To go out of the dilemma, in this work, we design an experimental method to achieve inverse flexoelectricity and propose a method to measure the inverse flexoelectric effect with a lower voltage at the macroscopic scale. The result shows that the flexoelectric coefficient of SrTiO3 (STO) single crystal from the inverse flexoelectric experiment has the same order of magnitude as that of the direct flexoelectric experiments. Furthermore, this method can be utilized to design an STO flexoelectric actuator on a macroscopic scale. The displacement resolution of flexoelectric actuators is as low as 0.42 pm V−1, which is three orders of magnitude lower than that of piezoelectric actuators. This type of flexoelectric actuator is important for precise driving and positioning.
Floquet engineering of interparticle correlations in electron-hole few-body system for strong radial confinement
Authors: Dziembaj G , Chwiej T
Published: October 2024

We investigate the effects of off-resonant THz-frequency laser light coupling to bound few-body electron–hole system, i.e. the exciton and negatively charged trion confined in quantum wire. To solve this problem, we first conduct a unitary Hennerberger-Kramers transformation of the Hamiltonian and diagonalize its perturbative approximation to obtain the exciton and trion Floquet states. Within this framework, the light-matter coupling renormalizes an attractive eh interaction, leaving the repulsive ee unchanged, thus modifying corresponding two-particle correlation energies. Generally, the correlation energy of eh would exceed the ee one for a semiconductor material with strongly localized heavy holes. However, as the former is weakened by increasing laser intensity, this relation can be reversed. Consequently, the trion may dissociate unconventionally, the hole gradually decouples from still strongly interacting electrons, and adequate energy and optical spectra changes accompany this process. The energy levels of the exciton and trion Floquet states are raised, while their optical brightness smoothly decreases for stronger laser intensities. We also show this process can be further modified by breaking the mirror symmetry of wire with a static electric field, and then the occurrence of the avoided crossings between the lowest energy levels of the trion depends on the laser intensity. These anticrossings shall be observed experimentally, confirming thus the usefulness of Floquet engineering for fast manipulations of the few-particle states in electron–hole systems on a subpicosecond time scale.
Topological and site disorder in boron nitride networks
Authors: Heafield Angus , Wilson Mark
Published: October 2024

Amorphous boron nitride (a-BN) is modelled over a wide range of densities using a relatively simple potential model augmented with site charges. The local topology (defined, for example, through the total nearest-neighbour coordination number), appears near-constant across a wide range of densities and site charges. Furthermore, total scattering and total pair distribution functions also show few changes as a function of either density or site charge. Variation of the site charges directly controls the level of site (rather than topological) disorder meaning that although total pair functions may be near-constant, the underlying partial contributions may be very different. Direct contact is made with both experiment and (more recent) density-functional theory-based modelling work.
Tight-binding model of Pt-based jacutingaites as combination of the honeycomb and kagome lattices
Authors: Santos-Castro G , Teles L K , Guilhon Mitoso I , Pereira Jr J M
Published: October 2024

We introduce a refined tight-binding (TB) model for Pt-based jacutingaite materials

Pt

2

NX

3

, (

N

= Zn, Cd, Hg; X = S, Se, Te), offering a detailed representation of the low-energy physics of its monolayers. This model incorporates all elements with significant spin–orbit coupling contributions, which are essential for understanding the topological energy gaps in these materials. Through comparison with first-principles calculations, we meticulously fitted the TB parameters, ensuring an accurate depiction of the energy bands near the Fermi level. Our model reveals the intricate interplay between the Pt 3e and N metal orbitals, forming distinct kagome and honeycomb lattice structures. Applying this model, we explore the edge states of Pt-based jacutingaite monolayer nanoribbons, highlighting the sensitivity of the topological edge states dispersion bands to the nanostructures geometric configurations. These insights not only deepen our understanding of jacutingaite materials but also assist in tailoring their electronic properties for future applications.
Multi-technique based coarse to fine form registration for ultra-precision diamond milling of freeform optics
Authors: Wu Panyue , Guo Pan , Xiong Zhiwen , Dong Zengwen , Zhang Shaojian
Published: October 2024

Due to its excellent optical performance, freeform optics has found extensive applications into sophisticated optical systems. Ultra-precision diamond milling (UPDM) offers an advanced solution for manufacturing high-quality freeform optics with sub-micrometric form error. However, its varying curvature characteristics would lead to uneven residual and inconsistent surface quality. Therefore, to improve the registration process accuracy, this study proposes a multi-technique based coarse to fine form registration for UPDM of freeform optics and it provides a benchmark for evaluating the form error of machined surfaces. Firstly, two-dimensional Fourier transform and Pearson correlation coefficient were used for area coarse registration. Next, singular value decomposition was utilized to transform the coordinate systems for fine registration. Then, simulations were performed to construct two representative freeform optics-light emitting diode lens and virtual reality lens-and their forms were registered. Finally, the form error between the designed and measured surfaces was discussed in UPDM experiments. The results revealed that the proposed form registration method demonstrated strong robustness and accuracy under various errors. After registering simulation, the peak to valley and root mean square deviations between the designed surface and the measured surface of the two types of freeform optics were both less than 10−7 μm. Significantly, this study applies advanced mathematical tools in the form registration and thus improves the precision and efficiency of form registration in freeform optics.
Research on noise reduction method of centrifugal pump coupling fault signal based on LMD-FE-IWT
Authors: Houlin Liu , Xiao Li , Wen Xu , Haochen Ma , Liang Dong
Published: October 2024

Aiming at the problem that the coupling fault signal of centrifugal pump presents the complexity of mutual coupling due to the mutual influence of various fault components, and it is easy to be affected by the surrounding environmental noise, which leads to the difficulty of noise reduction, the LMD-FE-IWT noise reduction method is proposed. This method first utilizes local mean decomposition (LMD) to adaptively decompose the vibration signal, and calculates the fuzzy entropy of each component. According to fuzzy entropy, the components are divided into two categories: disordered and ordered. After the improved wavelet threshold denoising of the disordered component, it is reconstructed with the ordered component to achieve the denoising effect. By analying the simulation signal and experimental data, the results show that, the proposed method outperforms other methods, with improvements in signal-to-noise ratio by 55.95%, 48.86%, and 31.71% for the simulation signal noise reduction. The effect is significant, enabling the effective extraction of characteristic frequencies associated with different faults for the experimental signal noise reduction.
Room-temperature infrared photoluminescence and broadband photodetection characteristics of Ge/GeSi islands on silicon-on-insulator
Authors: Singh Sudarshan , John John Wellington , Sarkar Arijit , Dhyani Veerendra , Das Samaresh , Ray Samit K
Published: October 2024

In this study, molecular beam epitaxial growth of strain-driven three-dimensional self-assembled Ge/GeSi islands on silicon-on-insulator (SOI) substrates, along with their optical and photodetection characteristics, have been demonstrated. The as-grown islands exhibit a bimodal size distribution, consisting of both Ge and GeSi alloy islands, and show significant photoluminescence (PL) emission at room temperature, specifically near optical communication wavelengths. Additionally, these samples were used to fabricate a Ge/GeSi islands/Si nanowire based phototransistor using a typical e-beam lithography process. The fabricated device exhibited broadband photoresponse characteristics, spanning a wide wavelength range (300–1600 nm) coupled with superior photodetection characteristics and relatively low dark current (∼ tens of pA). The remarkable photoresponsivity of the fabricated device, with a peak value of ∼11.4 A W−1 (λ ∼ 900 nm) in the near-infrared region and ∼1.36 A W−1 (λ ∼ 1500 nm) in the short-wave infrared (SWIR) region, is a direct result of the photoconductive gain exceeding unity. The room-temperature optical emission and outstanding photodetection performance, covering a wide spectral range from the visible to the SWIR region, showcased by the single layer of Ge/GeSi islands on SOI substrate, highlight their potential towards advanced applications in broadband infrared Si-photonics and imaging. These capabilities make them highly promising for cutting-edge applications compatible with complementary metal-oxide-semiconductor technology.
Using Arduino to study two-degree-of-freedom mass-spring system
Authors: Escudero Raquel , Barrere Nicasio , Rodríguez Chialanza Mauricio
Published: October 2024

The study of oscillations is one of the topics included in undergraduate-level physics courses. This work demonstrates the use of ultrasound sensors and Arduino boards to study coupled oscillations. According to the configuration presented, it is possible to study the motion depending on the system’s initial conditions. This system allows students to expand the possibility of experiments.
MFCA-MICNN: a convolutional neural network with multiscale fast channel attention and multibranch irregular convolution for noise removal in dMRI
Authors: Ai Lingmei , Shi Yunfan , Yao Ruoxia , Li Liangfu
Published: October 2024

Diffusion magnetic resonance imaging (dMRI) currently stands as the foremost noninvasive method for quantifying brain tissue microstructure and reconstructing white matter fiber pathways. However, the inherent free diffusion motion of water molecules in dMRI results in signal decay, diminishing the signal-to-noise ratio (SNR) and adversely affecting the accuracy and precision of microstructural data. In response to this challenge, we propose a novel method known as the Multiscale Fast Attention-Multibranch Irregular Convolutional Neural Network for dMRI image denoising. In this work, we introduce Multiscale Fast Channel Attention, a novel approach for efficient multiscale feature extraction with attention weight computation across feature channels. This enhances the model’s capability to capture complex features and improves overall performance. Furthermore, we propose a multi-branch irregular convolutional architecture that effectively disrupts spatial noise correlation and captures noise features, thereby further enhancing the denoising performance of the model. Lastly, we design a novel loss function, which ensures excellent performance in both edge and flat regions. Experimental results demonstrate that the proposed method outperforms other state-of-the-art deep learning denoising methods in both quantitative and qualitative aspects for dMRI image denoising with fewer parameters and faster operational speed.
Imaging error reduction in radial cine-MRI with deep learning-based intra-frame motion compensation
Authors: Sui Zhuojie , Palaniappan Prasannakumar , Paganelli Chiara , Kurz Christopher , Landry Guillaume , Riboldi Marco
Published: October 2024

Objective. Radial cine-MRI allows for sliding window reconstruction at nearly arbitrary frame rate, promising high-speed imaging for intra-fractional motion monitoring in magnetic resonance guided radiotherapy. However, motion within the reconstruction window may determine the location of the reconstructed target to deviate from the true real-time position (target positioning errors), particularly in cases of fast breathing or for anatomical structures affected by the heartbeat. In this work, we present a proof-of-concept study aiming to enhance radial cine-MR imaging by implementing deep-learning-based intra-frame motion compensation techniques. Approach. A novel network (TransSin-UNet) was proposed to continuously estimate the final-position image of the target, corresponding to end of the frame acquisition. Within the radial k-space reconstruction window, the spatial–temporal dependencies among the sinogram representation of the spokes were modeled by a transformer encoder subnetwork, followed by a UNet subnetwork operating in the spatial domain for pixel-level fine-tuning. By simulating motion-dependent radial sampling with (tiny) golden angles, we generated datasets from 25 4D digital anthropomorphic lung cancer phantoms. The network was then trained and extensively evaluated across datasets characterized by varying azimuthal radial profile increments. Main Results. The method required additional 4.8 ms per frame over the conventional approach involving direct image reconstruction with motion-corrupted spokes. TransSin-UNet outperformed architectures relying solely on transformer encoders or UNets across all the comparative evaluations, leading to a noticeable enhancement in image quality and target positioning accuracy. The normalized root mean-squared error decreased by 50% from the initial value of 0.188 on average, whereas the mean Dice similarity coefficient of the gross tumor volume increased from 85.1% to 96.2% in the investigated cases. Furthermore, the final-positions of anatomical structures undergoing substantial intra-frame deformations were precisely derived. Significance. The proposed approach enables an effective intra-frame motion compensation, offering an opportunity to reduce errors in radial cine-MR imaging for real-time motion management.
Study of modulation in complex refractive indices induced by ultrafast relativistic electrons using infrared and THz probe pulses
Authors: Jeong Diana , Bark Hyeon Sang , Kim Yushin , Shin Junho , Kim Hyun Woo , Oang Key Young , Jang Kyu-Ha , Lee Kitae , Jeong Young Uk , Baek In Hyung , Levin Craig S
Published: October 2024

Objective. Achieving ultra-precise temporal resolution in ionizing radiation detection is essential, particularly in positron emission tomography, where precise timing enhances signal-to-noise ratios and may enable reconstruction-less imaging. A promising approach involves utilizing ultrafast modulation of the complex refractive index, where sending probe pulses to the detection crystals will result in changes in picoseconds (ps), and thus a sub—10 ps coincidence time resolution can be realized. Towards this goal, here, we aim to first measure the ps changes in probe pulses using an ionizing radiation source with high time resolution. Approach. We used relativistic, ultrafast electrons to induce complex refractive index and use probe pulses in the near-infrared (800 nm) and terahertz (THz, 300 µm) regimes to test the hypothesized wavelength-squared increase in absorption coefficient in the Drude free-carrier absorption model. We measured BGO, ZnSe, BaF2, ZnS, PBG, and PWO with 1 mm thickness to control the deposited energy of the 3 MeV electrons, simulating ionization energy of the 511 keV photons. Main results. Both with the 800 nm and THz probe pulses, transmission decreased across most samples, indicating the free carrier absorption, with an induced signal change of 11% in BaF2, but without the predicted Drude modulation increase. To understand this discrepancy, we simulated ionization tracks and examined the geometry of the free carrier distribution, attributing the mismatch in THz modulations to the sub-wavelength diameter of trajectories, despite the lengths reaching 500 µm to 1 mm. Additionally, thin samples truncated the final segments of the ionization tracks, and the measured initial segments have larger inter-inelastic collision distances due to lower stopping power (dE/dx) for high-energy electrons, exacerbating diffraction-limited resolution. Significance. Our work offers insights into ultrafast radiation detection using complex refractive index modulation and highlights critical considerations in sample preparation, probe wavelength, and probe-charge carrier coupling scenarios.
The effect of selenium ion concentration on zinc selenide thin films prepared by a photo-assisted chemical bath deposition method
Authors: Hile D D , Koao L F , Swart H C , Motloung S V , Ahemen I , Ndlangamandla C L
Published: October 2024

Zinc selenide (ZnSe) thin films were deposited on non-conducting glass substrates at different selenium concentrations using a photo-assisted chemical bath deposition method. The films were deposited for 2.0 h at 80 °C and annealed for 2.0 h at 250 °C. X-ray diffraction (XRD) revealed a hexagonal structure with preferential orientation along the (002) plane, and the crystallite sizes were about 9–11 nm. Raman scattering showed longitudinal optical phonon modes due to the ZnSe, and the effect of the selenium concentration was noticed on the peak intensities of the XRD and Raman scattering studies. Optical analysis showed higher absorbance in the visible region than near the infrared spectrum, making the thin films good materials for selective absorber surfaces. The estimated bandgap ranged between 2.37 and 2.70 eV. X-ray spectroscopy confirmed the presence of the desired elements and revealed that the ratio of selenium to zinc declined after the sample was prepared with 0.6 M selenium ions. Photoluminescence studies revealed three emission peaks, which were due to defect state levels in the ZnSe. By varying the selenium concentration, the ZnSe was tuned to a reddish color emission, as confirmed by Commission Internationale de L’Eclairage (CIE) color chromaticity analysis. The selective absorption, wide bandgap, and emission properties suggest that the material is promising for light-emitting device applications.