bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Symplectic Method for the Two-Component Camassa–Holm (2CH) System
Authors: Xi Xiaojian , Hu Weipeng , Tang Bo , Deng Pingwei , Qiao Zhijun
Published: July 2024

In this paper, the multi-symplectic formulations of the two-component Camassa–Holm system are presented. Both the multi-symplectic structure and two local conservation laws of the generalized two-component Camassa–Holm model are proposed for its first-order canonical form. Then, combining the Fourier pseudo-spectral method in the spatial domain with the midpoint method in the time dimension, the multi-symplectic Fourier pseudo-spectral scheme is constructed for the first-order canonical form. Meanwhile, the discrete scheme of the residuals of the multi-symplectic structure and two local conservation laws are also provided. By using the multi-symplectic Fourier pseudo-spectral scheme, the evolution of one- and two-soliton solutions for the generalized two-component Camassa–Holm model is regained. The structure-preserving properties and the reliability of the numerical scheme are illustrated by the tiny numerical residuals (less than 3.5 × 10−8) of the conservation laws as well as the tiny numerical variations (less than 1 × 10−9) of the amplitudes and the propagating velocities of the solitons.
Zusammenarbeit zwischen Pflegeteams und Pflegeexpert_innen in der ambulanten Pflege
Authors: Regez Aline , Preisig Marina , Domeisen Benedetti Franzisca
Published: July 2024

Zusammenfassung: Hintergrund: Durch den demografischen Wandel und der damit einhergehenden Hochaltrigkeit steigt die Anzahl der Personen, die von Multimorbidität betroffen sind, und damit die Komplexität der ambulanten Pflege. Im ambulanten Pflegedienst (Spitex) arbeiten Pflegeteams mit Mitarbeitenden von unterschiedlichen Kompetenzstufen. Zur Unterstützung in komplexen Situationen können sie auf Pflegeexpert_innen (PEX) zurückgreifen. Fragestellung/Ziel: Das Ziel war es, die Zusammenarbeit zwischen den Pflegeteams und den PEX einer regionalen Spitexorganisation zu untersuchen und Maßnahmen zur Optimierung auszuarbeiten. Die Fragestellung lautete: „Wie erleben die Pflegeteams einer regionalen Spitexorganisation die Zusammenarbeit mit den PEX?“ Methode: Ein qualitatives Case Study Design mit vier Subcases wurde verwendet, um detailliert zu beschreiben, wie die Zusammenarbeit mit PEX erlebt wird. Vier Fokusgruppeninterviews wurden mittels Inhaltsanalyse und Cross-Case Analyse ausgewertet. Ergebnisse: In der Cross-Case-Analyse zeigen sich die Kategorien für eine optimale Zusammenarbeit: präsent, fachlich vielseitig, entlastend in Koordinationsaufgaben, unterstützend in komplexen Situationen. Folgende Kategorien werden als Störfaktoren in der Zusammenarbeit beschrieben: unterschiedlich engagiert, Zusammenarbeit niedrige Priorität, unübersichtlich. Schlussfolgerungen: Die PEX sollen mittels gezielter Informationsvermittlung bekannter gemacht werden. Als Implikation für die Praxis sind unter anderem Präsenz und gegenseitiges Rollenverständnis wichtig, damit die Zusammenarbeit als Mehrwert erlebt wird.
The Transition to Double‐Celled Circulations in Mock‐Walker Simulations
Authors: Lutsko Nicholas J. , Cronin Timothy W.
Published: July 2024

Mock‐Walker simulations have the potential to play a key role in a tropical model hierarchy, bridging small‐scale Radiative‐Convective Equilibrium simulations and global models of tropical circulations. We demonstrate that mock‐Walker simulations transition from single‐ to double‐celled overturning circulations as mean Sea Surface Temperature (SST) is increased, with the transition occurring near 300 K. The transition is robust to domain geometry and microphysical scheme, and is favored by larger SST gradients. The transition is associated with the development of a mid‐tropospheric minimum in the radiative‐subsidence velocity over the cold pool of the simulations, and is likely reinforced by zonal moisture and temperature fluxes between the warm and cold pools. Several methods of suppressing the transition are investigated, but all set‐ups produce a double‐cell at sufficiently warm mean SSTs. The striking dynamical transition of mock‐Walker simulations dominates their response to warming, though its relevance for observed tropical climate change is unclear.
ID2-ETS2 axis regulates the transcriptional acquisition of pro-tumoral microglia phenotype in glioma
Authors: Vázquez-Cabrera Guillermo , Škandík Martin , Roncier Noémie , Real Oualit Farah , Cruz De Los Santos Mireia , Baleviciute Austeja , Cheray Mathilde , Joseph Bertrand
Published: July 2024

Glioblastoma is a highly aggressive brain tumour that creates an immunosuppressive microenvironment. Microglia, the brain’s resident immune cells, play a crucial role in this environment. Glioblastoma cells can reprogramme microglia to create a supportive niche that promotes tumour growth. However, the mechanisms controlling the acquisition of a transcriptome associated with a tumour-supportive microglial reactive state are not fully understood. In this study, we investigated changes in the transcriptional profile of BV2 microglia exposed to C6 glioma cells. RNA-sequencing analysis revealed a significant upregulation of microglial inhibitor of DNA binding 1 (Id1) and Id2, helix-loop-helix negative transcription regulatory factors. The concomitant regulation of microglial ETS proto-oncogene 2, transcription factor (ETS2)-target genes, i.e., Dusp6, Fli1, Jun, Hmox1, and Stab1, led us to hypothesize that ETS2 could be regulated by ID proteins. In fact, ID2-ETS2 protein interactions increased in microglia exposed to glioma cells. In addition, perturbation of the ID2-ETS2 transcriptional axis influenced the acquisition of a microglial tumour-supportive phenotype. ID2 and ETS2 genes were found to be expressed by the tumour-associated microglia isolated from human glioblastoma tumour biopsies. Furthermore, ID2 and ETS2 gene expressions exhibited inverse prognostic values in patients with glioma in cohorts from The Cancer Genome Atlas. Collectively, our findings indicate that the regulation of ETS2 by ID2 plays a role in the transcriptional regulation of microglia in response to stimuli originating from glioblastoma cells, information that could lead to developing therapeutic strategies to manipulate microglial tumour-trophic functions.
Super-twisting MPPT control for grid-connected PV/battery system using higher order sliding mode observer
Authors: Dunna Vijaya Kumar , Chandra Kumar Pakki Bharani , Rout Pravat Kumar , Sahu Binod Kumar , Manoharan Premkumar , Alsoud Anas R. , Derebew Bizuwork
Published: July 2024

In recent times, photovoltaic (PV) power generation has been growing due to increase in energy demand. In grid-connected mode, achieving maximum power (MP) from the PV array is difficult by using conventional techniques due to various reasons like low tracking efficiency, stability issues, etc. This motivates the design of an appropriate control strategy to obtain the maximum power point tracking (MPPT) to harvest MP from the PV array. This paper proposes a combined higher order sliding mode observer (HOSMO)–super-twisting control (STC) for a grid-connected scenario. A perturb and observe (P &O) technique is employed to generate reference voltage, and a HOSMO is proposed to drive the STC by estimating the inductor current of the PV boost converter. The proposed controller performance is evaluated based on response time across various scenarios, including generation changes, dynamic faults, islanding and resynchronization, and load variations in comparison to other existing controllers. These microgrid test cases have been thoroughly simulated, and their effectiveness has been validated in real-time using OPAL-RT (OP4510).
Dynamic evaluation of corneal cross-linking and osmotic diffusion effects using optical coherence elastography
Authors: Frigelli Matteo , Büchler Philippe , Kling Sabine
Published: July 2024

Dynamic deformation events induced by osmosis or photochemical stiffening substantially influence geometrical and mechanical assessments in post-mortem corneas, therefore need to be carefully monitored in experimental settings. In this study, we employed optical coherence elastography (OCE) to quantify dynamic deformation processes at high resolution in freshly enucleated porcine corneas. Osmotic effects were studied by immerging n = 9 eyes in preservation media of three different tonicities. Dynamic processes underlying corneal cross-linking (CXL) were studied by subjecting n = 6 eyes to standard Dresden treatment, while three control groups were used. The entire procedures were performed under an OCE setup during up to 80 min, acquiring a volumetric scan every 20 s. Changes in OCE-derived axial deformations were incrementally calculated between consecutive scans. Preservation conditions had a strong influence on the observed strain patterns, which were consistent with the tonicity of the medium (swelling in hypotonic, deswelling in hypertonic environment). In the CXL group, we observed deswelling of the anterior stroma 10 min after starting the UV irradiation, which was not observed in any control group (p = 0.007). The presented results proved OCE to be a valuable technique to quantify subtle dynamic biomechanical alterations in the cornea resulting from CXL and preservation solutions.
Assessment of Arctic sea ice simulations in cGENIE model and projections under RCP scenarios
Authors: Chen Di , Fu Min , Liu Xin , Sun Qizhen
Published: July 2024

Simulating and predicting Arctic sea ice accurately remains an academic focus due to the complex and unclear mechanisms of Arctic sea ice variability and model biases. Meanwhile, the relevant forecasting and monitoring authorities are searching for models to meet practical needs. Given the previous ideal performance of cGENIE model in other fields and notable features, we evaluated the model’s skill in simulating Arctic sea ice using multiple methods and it demonstrates great potential and combined advantages. On this basis, we examined the direct drivers of sea-ice variability and predicted the future spatio-temporal changes of Arctic sea ice using the model under different Representative Concentration Pathways (RCP) scenarios. Further studies also found that Arctic sea ice concentration shows large regional differences under RCP 8.5, while the magnitude of the reduction in Arctic sea ice thickness is generally greater compared to concentration, showing a more uniform consistency of change.
A memristive circuit for self-organized network topology formation based on guided axon growth
Authors: Jenderny Sebastian , Ochs Karlheinz , Xue Daniel
Published: July 2024

Circuit implementations of neuronal networks so far have been focusing on synaptic weight changes as network growth principles. Besides these weight changes, however, it is also useful to incorporate additional network growth principles such as guided axon growth and pruning. These allow for dynamical signal delays and a higher degree of self-organization, and can thus lead to novel circuit design principles. In this work we develop an ideal, bio-inspired electrical circuit mimicking growth and pruning controlled by guidance cues. The circuit is based on memristively coupled neuronal oscillators. As coupling element, we use memsensors consisting of a general sensor, two gradient sensors, and two memristors. The oscillators and memsensors are arranged in a grid structure, where oscillators and memsensors realize nodes and edges, respectively. This allows for arbitrary 2D growth scenarios with axon growth controlled by guidance cues. Simulation results show that the circuit successfully mimics a biological example in which two neurons initially grow towards two target neurons, where undesired connections are pruned later on.
The association between visceral adiposity index and risk of type 2 diabetes mellitus
Authors: Zhou Haoran , Li Tianshu , Li Jie , Zhuang Xin , Yang Jie
Published: July 2024

Relationships between the visceral adiposity index (VAI) and type 2 diabetes mellitus (T2DM) have been underexplored. The purpose of this study is to explore association between VAI and T2DM in adults in the US. Based on the National Health and Nutrition Examination Survey 2007–2018, 11,214 participants aged 20 years or older were included in a cross-sectional study. Multifactorial logistic regression analysis and smoothed curve fitting analysis were performed to investigate links between VAI and the prevalence of T2DM, as well as the stability and incidence between subgroups. In a fully adjusted continuous model, the aggregate population risk of T2DM increased 0.43-fold with each 1-unit increase in VAI [odds ratio (OR) = 1.43; 95% confidence interval (CI) 1.35–1.50]. In the fully adjusted categorical model with VAI scores stratified by quartiles, results showed a higher T2DM advantage among participants in the second, third, and fourth quartiles (Q2: OR 1.35, 95% CI 1.06–1.71; Q3: OR 2.46, 95% CI 1.95–3.11; Q4: OR 4.42, 95% CI 3.55–05.50). Compared with Q1, the prevalence of T2DM in the total population increased 3.42-fold in Q4. The above results indicated that VAI was positively associated with the prevalence of T2DM, which was consistent and nonlinear with the smoothed curve-fitting analysis (P for non-linear = 0). Subgroup analyses after adjusting for covariates showed that keeping with the overall population results, it also was found that there was an interaction between sex and hypertension in the subgroups. VAI was positively associated with the prevalence of T2DM and was more prevalent in women, non-hypertensive than in men, hypertensive populations.
The actin binding protein profilin 1 localizes inside mitochondria and is critical for their function
Authors: Read Tracy-Ann , Cisterna Bruno A , Skruber Kristen , Ahmadieh Samah , Liu Tatiana M , Vitriol Josefine A , Shi Yang , Black Joseph B , Butler Mitchell T , Lindamood Halli L , Lefebvre Austin EYT , Cherezova Alena , Ilatovskaya Daria V , Bear James E , Weintraub Neal L , Vitriol Eric A
Published: July 2024

The monomer-binding protein profilin 1 (PFN1) plays a crucial role in actin polymerization. However, mutations in PFN1 are also linked to hereditary amyotrophic lateral sclerosis, resulting in a broad range of cellular pathologies which cannot be explained by its primary function as a cytosolic actin assembly factor. This implies that there are important, undiscovered roles for PFN1 in cellular physiology. Here we screened knockout cells for novel phenotypes associated with PFN1 loss of function and discovered that mitophagy was significantly upregulated. Indeed, despite successful autophagosome formation, fusion with the lysosome, and activation of additional mitochondrial quality control pathways, PFN1 knockout cells accumulate depolarized, dysmorphic mitochondria with altered metabolic properties. Surprisingly, we also discovered that PFN1 is present inside mitochondria and provide evidence that mitochondrial defects associated with PFN1 loss are not caused by reduced actin polymerization in the cytosol. These findings suggest a previously unrecognized role for PFN1 in maintaining mitochondrial integrity and highlight new pathogenic mechanisms that can result from PFN1 dysregulation.
New light-illuminated silk road: emerging silk fibroin-based optical biomedical sensors
Authors: Dong Kaiyi , Zhou Qian , Gao Bingbing
Published: July 2024

Biomedical silk protein optics has become the subject of intensive research aimed at solving the challenges associated with traditional medical devices in terms of biocompatibility and performance balance.
In situ confinement of ultra-small metal nanoparticles in redox-active zirconium MOFs for catalysis
Authors: Li Fugang , Huang Jinyi , Meng Yuxuan , Li Ji , Zhang Liangliang , Sheng Daopeng
Published: July 2024

Two kinds of stable and redox-active Zr-MOFs were successfully prepared, which allow generating and stabilizing ultra-small Pd nanoparticles in situ for heterogenous catalysis.
Using potassium bromide pellets and optical spectroscopy to assess the photodimerization of two trans-(trifluoromethyl)-cinnamic acid compounds
Authors: Ulambayar Bayasgalan , Batchuluun Khongorzul , Bariashir Chantsalnyam , Uranbileg Nergui , Stammler Felix J. , Davaasambuu Jav , Schrader Tobias E.
Published: July 2024

Solid state photoreactions are an attractive route to produce special isomers due to the crystal packing of the starting molecules. We use powder samples pressed into potassium bromide pellets to investigate photoreactions with optical spectroscopy.
A subnano-confinement in robust MoS2-based membranes for high-performance osmotic energy conversion
Authors: Wang Xuying , Wang Zhaoyi , Xue Zhiwei , Fan Yiyi , Yang Jing , Zhang Qingxiao , Yang Naitao , Meng Xiuxia , Jin Yun , Liu Shaomin
Published: July 2024

A robust MoS2-based membrane with a subnano-scale confinement for Na+ transport has achieved an osmotic power density of 73 W m−2 under a 50-fold concentration gradient and exceptional stability of 40 days with the tested membrane area of 0.78 mm2.
A universal route to graft highly dispersed cobalt phthalocyanine on porous carbon for efficient CO2 electroreduction
Authors: Wu Shide , Gao Mengjin , Ping Dan , Huang Siguang , Zhang Qikang , Liu Shuqing , Wang Zheming , Fang Shaoming
Published: July 2024

A promising catalyst for dispersing CoPc on three-dimensional porous carbon was prepared and showed impressive performance for CO2 electroreduction to CO.
Anatase TiO2 film with dominant (001) facets prepared by radio frequency atmospheric pressure plasma
Authors: Zhang Yu , Wang Haozhe , Cui Jie , He Tao , Xu Yu , Zhang Jing
Published: July 2024

Anatase TiO2 nanosheets film with dominant (001) facets (TF-1) has attracted widespread research interest owing to wide-ranging industrial applications and fundamental importance. In this work, we prepared TF-1 with well adhesion on quartz substate in a short time (20 min) by radio frequency (RF) pulse-modulated plasma with hydrofluoric acid (HF) as the morphology controlling agent (MCA). Many intercrossed nanosheets were observed on the surface of TF-1 through SEM images, which provides more exposed reactive (001) facets. The degree of truncation (B/A) and the percentage of exposed (001) facets (S001/S) were estimated by XRD patterns and Raman spectra, which have been increased due to the presence of HF. XPS results indicate that F atoms are only adsorbed on anatase surface rather than doped into TiO2 lattice. The functions of HF on the growth of anatase TiO2 nanosheets were studied by density functional theory (DFT), revealing the stabilization effects associated with chemisorbed fluorine (F) atoms over (001) surface, and thus stimulating its preferred growth.
Pratique de l’éducation thérapeutique du patient en Tunisie : Point de vue du praticien
Authors: Saïd Fatma , Naceur Ines , Jebri Mériem , Ben Achour Tayssir , Smiti Monia , Houman Mohamed Habib
Published: July 2024

Introduction : L’éducation thérapeutique des patients (ETP) traités par un antivitamine K (AVK) permet d’améliorer la sécurité et l’efficience de ce traitement en établissant une meilleure relation médecin-malade. L’objectif de notre étude est d’établir un état des lieux de la pratique de l’ETP auprès des médecins prescripteurs d’un AVK. Méthodes : Nous avons réalisé une étude transversale descriptive colligeant les réponses des médecins à un questionnaire électronique. Résultats : Parmi 92 médecins, 85 % avaient adopté avec leurs patients une démarche éducative, dont 65 % avaient eu une formation post-universitaire en ETP et 22 % se référaient à des ressources internationales pour guider leur pratique d’ETP. Le principal frein à la pratique de l’ETP était des contraintes organisationnelles (N = 12). Conclusion : La création de recommandations nationales en matière d’ETP et l’intégration de celle-ci dans la formation médicale et paramédicale sont primordiales.
Transition-Metal-Catalyzed Rapid Synthesis of Imidazo[2,1-b]thiazoles: Access to Aza-Fused Heterocycles via Aerobic Oxidative Coupling of 2-Aminothiazoles and Acetophenones
Authors: Dash Jyotirmayee , Basak Soumya Jyoti , Paul Pratap
Published: July 2024

We report an efficient synthesis of 6-substituted imidazo[2,1-b]thiazoles from 2-aminothiazoles and acetophenones through intramolecular cyclization of in situ generated thiazolium ylides. This one-pot cascade process efficiently forms two C–N bonds and is facilitated by both Cu(OTf)2/KI and FeCl3/ZnI2 systems. The method utilizes commercially available starting materials and features mild reaction conditions, tolerance to different functional groups, and ease of operation. The synthetic applicability has further been demonstrated through post-modification of imidazo[2,1-b]thiazole analogues.
Assessment of Cancer Chemotherapy Needs in Patients Attending Tertiary Care Cancer Center, q: A Cross-Sectional Study
Authors: Prakash G Hari , D. Sunil Kumar , K. Kiran P. , Arun Vanishri , Yadav Deepika
Published: July 2024

Introduction Globally, 19.3 million new cancer cases were diagnosed in 2020, with over 10.0 million cancer deaths. Patients with cancer often face various long-term physical, social, financial, psychological, and existential challenges, complicating their survivorship.

Objectives This study aimed to evaluate the different needs of patients undergoing chemotherapy at a tertiary care cancer center.

Materials and Methods Data were collected from a tertiary care cancer center using purposive sampling. A total of 101 samples were collected over a 2-month period.

Results The majority of participants were female (61.4%), with 38.6% being male. Most participants were in the third stage of cancer (57.4%), with 42.6% in the fourth stage. Localized metastasis was observed in 83.2% of participants. The most common symptoms were lack of appetite (59.4%) and nausea/vomiting (54.5%). Most participants rated the care provided by nurses during chemotherapy as good (86.1%). The majority had moderate needs (67.3%) during the treatment course.

Conclusion The study highlights significant needs in the physical and psychological domains among patients undergoing chemotherapy.
Anti-Mullerian Hormone Assessment in Assisted Reproductive Technique Outcome and Natural Conception
Authors: Sellami Inès , Barbotin Anne Laure , Bernard Valérie , Robin Geoffroy , Catteau-Jonard Sophie , Sonigo Charlotte , Peigné Maeliss
Published: July 2024

In recent years, the prevalence of infertility has increased, and appears to affect approximately one in six couples. Some of them must perform assisted reproductive techniques (ART) in order to achieve pregnancy. As a result, growing interest has arisen about predictive factors of pregnancy and live birth with and without ART. Anti-Mullerian hormone (AMH) is a glycoprotein discovered in the 1950s in male embryonic sexual differentiation. Later, in 1984, its role in folliculogenesis was reported: secreted by granulosa cells, this hormone is involved in the regulation of the recruitment of primordial follicles and in follicular growth. AMH assays were developed for women in 1990s, and the serum AMH level has rapidly become a crucial element in managing women's fertility. Based mainly on its ability to be a quantitative but indirect marker of ovarian reserve, the serum AMH assay is widely used in reproductive medicine and ART. This review summarizes current knowledge of the AMH assessment in the field of reproductive medicine. We focus on the role of AMH level to predict spontaneous pregnancy occurrence, ART outcomes, and fertility preservation outcomes.
Precursor B Cell Acute Lymphoblastic Leukemia Presenting with Repeated Episodes of Hemophagocytic Lymphohistiocytosis
Authors: Desai Nihar , Chandra Dinesh , Gupta Ruchi , Kashyap Rajesh
Published: July 2024

Hemophagocytic lymphohistiocytosis (HLH) is a rare disorder characterized by dysregulated activation of cytotoxic T-lymphocytes and macrophages, resulting in excessive cytokine release and tissue damage. Although hematological malignancies and the chemotherapies used to treat them are frequently identified as triggering factors for HLH, B lymphoid leukemias are rarely implicated. In this report, we present an interesting case of a patient who presented with symptoms of HLH and was subsequently diagnosed with B-cell acute lymphoblastic leukemia. The further course of chemotherapy was complicated by another episode of HLH. This case highlights the complexity and the diverse triggers of HLH in the context of B lymphoid leukemia. Recognizing this atypical presentation is important to institute timely management strategies.
Collisionless heating in Vlasov plasma and turbulence-driven filamentation aspects
Authors: Ghizzo A. , Del Sarto D. , Betar H.
Published: July 2024

Reversible energy conversion between magnetic and kinetic energies has been recently demonstrated in a system of counterstreaming electron beams [see A. Ghizzo et al., Phys. Rev. Lett. 131, 035101 (2023)]. During the first step of the instability, the growth of a current-driven filamentation magnetic field is observed when propagative oblique solutions are considered, followed by the reversal of energy transfer from magnetic to kinetic energy in a second step. This highlights a new physical mechanism of the Vlasov equation: the enhancement of filamentation of the distribution function in the presence of the phase synchronization of the Van Kampen eigenmodes. This gives rise to a bifurcation toward self-organization and to a strong plasma heating. This new plasma heating mechanism possibly provides a new perspective on the role played by the filamentation in phase space in the relativistic regime of Weibel-type instabilities.
Exploring tear viscosity with quartz crystal microbalance technology
Authors: Muñoz G. , Millicovsky M. , Cerrudo J. , Peñalva A. , Machtey M. , Reta J. , Torres R. , Campana D. , Zalazar M.
Published: July 2024

Tear viscosity is a critical property affecting tear distribution and ocular surface stability. While not widely established as a primary diagnostic marker, deviations from normal viscosity can impact ocular health, potentially contributing to conditions such as dry eye syndrome. Despite their importance, traditional viscometers require sample volumes that are not feasible to use with tear volume. This research introduces a novel Quartz Crystal Microbalance (QCM)-based method for tear viscosity measurement, offering a viscometer prototype that operates with minimal sample volumes. Human tear samples, solutions used in artificial eye drops, and various commercial eye drop brands were evaluated. Results show that the QCM method aligns with established viscosity ranges. The average viscosity of healthy human tears was found to be 1.73 ± 0.61 cP, aligning with the typical range of 1–10 cP. Variability in the viscosities of eye drop can be attributed to differences in their chemical compositions. The QCM method offers benefits such as reduced sample consumption and rapid results, enhancing understanding of tear dynamics for ocular health. Further research with larger sample sizes is needed to establish normative viscosity values in healthy individuals and those with dry eye syndrome, which is crucial for validating the device’s clinical efficacy.
Efficient spatial separation for chiral molecules via optically induced forces
Authors: Cheng Jian-Jian
Published: July 2024

We investigate an efficient spatial enantioseparation method of chiral molecules in cyclic three-level systems coupled with three optical fields using optically induced forces. When the overall phase differs by π between two enantiomers, significant variations in the magnitude and direction of the optically induced forces are observed. The manipulation of the center of mass of chiral molecules in optical fields can be achieved through the induced gauge force, primarily generated from the variations in the chirality-dependent scalar potentials created by the three inhomogeneous laser fields. By appropriately configuring the system, we can completely separate the slow spatial and fast inner dynamics, making instantaneous eigenstates of the inner Hamiltonian independent of the transverse profiles of the laser beams. Compared to previous methods, which required adiabatic conditions to be satisfied, the proposed method overcomes the limitations of the adiabatic approximation by utilizing a specific system configuration. This allows for increased flexibility in the transverse profiles of the laser beams and relaxes the constraints on the velocity of chiral molecules, leading to significantly greater spatial separations achievable across a broader range of parameters.
Flow physics behind the wake of a flapping hydrofoil turbine near a wall
Authors: Yao Huilan , Wang Liangjiao , Zhang Huaixin , Liu Yong
Published: July 2024

By solving Reynolds-Averaged Navier–Stokes equations with the shear stress transport k–ω turbulence model, the two-dimensional wake of a flapping hydrofoil turbine near a wall was studied, including evolution of vortices, spatial distribution of velocity, time-averaged and time-varying characteristics of the flow field. A custom adaptive mesh refinement approach was used for vortex simulations. Unlike the double-row configuration wake behind a flapping hydrofoil turbine in no near-wall situation, the wake of a flapping hydrofoil turbine near a wall shows an approximate single-row vortex pattern, which makes the wake energy more concentrated and beneficial for recovery by downstream turbines. As the near-wall spacing decreases, the intensity of vortices gradually increases, but the change in the degree of vortex diffusion toward the side is non-monotonic. Especially, due to the continuous diffusion of vortices to the side, several equally spaced velocity recovery zones are formed near the centerline, which improves the conditions for energy recovering. As the pitching amplitude increases, the degree of vortex diffusion to the side monotonically decreases; the intensity of vortices increases, which exacerbates the unevenness of velocity field. As the motion frequency increases, the degree of vortex diffusion monotonically increases, the velocity attenuation is more severe, and the trajectories of all vortices become increasingly consistent. Anyway, the velocity intensification stabilization and fluctuation zones in the wake are the top two choices for installing downstream turbines. The study expands our understanding of the wake of a flapping hydrofoil turbine and can provide reference for improving the power of downstream turbines.
Fourier neural operator for large eddy simulation of compressible Rayleigh–Taylor turbulence
Authors: Luo Tengfei , Li Zhijie , Yuan Zelong , Peng Wenhui , Liu Tianyuan , Wang Liangzhu (Leon) , Wang Jianchun
Published: July 2024

The Fourier neural operator (FNO) framework is applied to the large eddy simulation (LES) of three-dimensional compressible Rayleigh–Taylor turbulence with miscible fluids at Atwood number At=0.5, stratification parameter Sr = 1.0, and Reynolds numbers Re = 10 000 and 30 000. The FNO model is first used for predicting three-dimensional compressible turbulence. The different magnitudes of physical fields are normalized using root mean square values for an easier training of FNO models. In the a posteriori tests, the FNO model outperforms the velocity gradient model, the dynamic Smagorinsky model, and implicit large eddy simulation in predicting various statistical quantities and instantaneous structures, and is particularly superior to traditional LES methods in predicting temperature fields and velocity divergence. Moreover, the computational efficiency of the FNO model is much higher than that of traditional LES methods. FNO models trained with short-time, low Reynolds number data exhibit a good generalization performance on longer-time predictions and higher Reynolds numbers in the a posteriori tests.
Calibration and characterization of optical and x-ray streak cameras using a Ti:Sapphire laser system
Authors: Penman R. R. , Marshall G. , Pitt S. F. , Oades K.
Published: July 2024

Optical and x-ray streak cameras are used to study transient phenomena, particularly in the high-energy density physics regime. The Orion laser facility employs many different types of streak cameras, which are used to collect data on laser-plasma interactions as well as to verify the temporal profile and timing between the multiple Orion beamlines. Streak cameras are complex devices with very precise timing associated with them, which can often malfunction, resulting in the loss of shot data. Since Orion is a kJ-class Nd:glass laser system, it is not optimal to try and fault-find using Orion shots since this is both time consuming and prohibitively expensive. To enable the facile set-up, fault-finding, timing-in, and in-house calibration of Orion optical and x-ray diagnostics, a single laboratory system has been commissioned to provide an adjustable stimulus to streak cameras and other Orion short pulse diagnostics (such as pulse dilation photomultiplier tubes). The system comprises a Ti:Sapphire laser system capable of generating 400 nm or 266 nm laser pulses of duration less than 0.1 ps; an optical system to deliver single pulses, pulse pairs, or a train of pulses; and timing electronics to synchronize the streak cameras with the laser and to record output data. The system can operate at Hertz repetition rates rather than the sub-mHz rate of the Orion laser. We present the commissioned system and results from initial testing of both optical and x-ray streak cameras used on Orion laser-plasma experiments.
Shallow water equations with binary porosity and their application to urban flooding
Authors: Varra Giada , Cozzolino Luca , Della Morte Renata , Soares-Frazão Sandra
Published: July 2024

Climate change and urbanization, among various factors, are expected to exacerbate the risk of flood disasters in urban areas. This prompts the construction of appropriate modeling tools capable of addressing full-scale urban floods for hazard and risk assessment. In this view, sub-grid porosity models based on the classic shallow water equations (SWE) appear to be a promising approach for full-scale applications in urban environments with reduced computational cost with respect to classic SWE models on high-resolution grids. The present work focuses on the recently proposed two-dimensional binary single porosity (BSP) model, which is a porosity flooding model written in differential form and based on the use of a binary indicator function to locate obstacles and buildings. Several applications (synthetic, experimental, and real-world cases) show that (i) the BSP results tend to the classic SWE solution for sufficiently refined mesh and that (ii) the BSP model can be successfully applied to realistic conditions with complicated terrain and obstacle distribution on coarser grids. Clearly, the adoption of medium/coarse grids makes the BSP model inherently less accurate than the classic SWE model on high-resolution grids, but the corresponding reduction of computational cost makes the use of the BSP model promising in full-scale urban flood applications when (i) multiple simulations are needed to perform stochastic or scenario analysis, (ii) no detailed information of local flow characteristics is required, and/or (iii) for complementing classic SWE models in a nesting cascade.
Characteristics of gel entrainment induced by gas recirculation in coaxial gas–liquid jets
Authors: Liu Wentao , Wang Zhichao , Zhao Hui , Li Weifeng , Liu Haifeng
Published: July 2024

Jet entrainment has a significant impact on the performance and longevity of coaxial atomizers. This study aims to investigate the entrainment characteristics of fluids with different rheological properties under coaxial gas–liquid jets through rheological experiments and high-speed flow visualization techniques. As the airflow velocity increases, the liquid jet exhibits non-entrained, entrained, and over-entrained modes. We found that only in the over-entrained mode does the entrained fluid come into contact with the nozzle outlet. The transition conditions for each mode are determined and plotted in a dimensionless map of We-Oh. A “bulge” structure on the surface of the liquid column at the nozzle outlet was observed within a specific gas velocity range, and its formation mechanism and characteristics were investigated. Theoretical models for two critical gas velocities were obtained by analyzing “initial entrainment” and “full entrainment” states in recirculation zones using total pressure conservation theory. The proposed model demonstrates its applicability to three distinct fluid media, namely, guar gum gel, glycerol, and water, exhibiting excellent agreement with the corresponding experimental results.
Fabrication and characterization of low loss niobium airbridges for superconducting quantum circuits
Authors: Tao Hao-Ran , Zhang Chi , Du Lei , Yang Xin-Xin , Guo Liang-Liang , Chen Yong , Zhang Hai-Feng , Jia Zhi-Long , Kong Wei-Cheng , Duan Peng , Guo Guo-Ping
Published: July 2024

Airbridges are extensively employed in superconducting quantum circuits to suppress parasitic slotline modes in coplanar waveguide and minimize crosstalk between control lines. Here, we introduce a fabrication technique for airbridges, leveraging niobium as the bridge layer and aluminum as the sacrificial layer to preclude the introduction of lossy dielectrics or residues upon release. Additionally, we utilize a triangular evaporation method to significantly bolster the structural integrity of the airbridges. Our experimental evaluation, focused on resonators equipped with these airbridges, reveals that the resultant additional loss per bridge is minimal, quantified at (5.0±2.8)×10−9 in the single-photon regime and (6.3±0.9)×10−9 at high drive powers. This advancement underscores the potential of niobium airbridges in facilitating the development of large-scale and high-performance superconducting quantum circuits.
Multi-channel GaN varactors and their current conduction mechanisms
Authors: Zou Wensong , Chen Jiawei , Hou Xiaoxiang , Xiang Peng , Cheng Kai , Zhang Qingfeng , Ma Jun
Published: July 2024

In this work, we demonstrate multi-channel GaN varactors with enhanced quality-factor (Q-factor) and cutoff frequency (f0) and present a comprehensive investigation of their current conduction mechanisms. The varactors were based on 1x-, 2x-, and 3x-channel GaN-on-SiC epitaxy with excellent channel conductivity, showing great enhancement of ∼270% both in Q-factor and in f0, thanks to the reduced resistance and capacitance by multi-channels in AC conduction. The DC leakage current (I) in the three types of devices is dominated by Poole–Frenkel (PF) emission and trap-assisted tunneling, before the depletion of the topmost channel and after the depletion of the bottommost channel, respectively. The I in multi-channel devices is dominated by two-dimensional variable range hopping of electrons along the vertical direction between channels, when the topmost channel is depleted while the bottommost channel is not. The analysis is supported by excellent agreement between experimental results and theoretical models, along with activation energies (EA) quantitatively and statistically determined, presenting a promising technology with key understandings for future performance enhancement.
Thermodynamic properties of R2Fe14B (R=Dy, Nd) and dysprosium random substitution effect on coercivity in neodymium permanent magnets
Authors: Nishino Masamichi , Hayasaka Hiroshi , Miyashita Seiji
Published: July 2024

Neodymium (Nd) magnets (Nd2Fe14B) are key materials for achieving high energy conversion efficiency. The coercive forces (fields) of the magnets are often reinforced by adding dysprosium (Dy), especially at high temperatures. To understand the magnetic properties of Dy-substituted systems (Nd1−xDyx)2Fe14B, it is important to study those of Dy2Fe14B and Nd2Fe14B and analyze the difference in detail from a microscopic viewpoint. Applying a recently developed atomistic model approach, we investigated thermodynamic properties of these magnets. We studied the temperature and field dependences of the magnetizations, and anisotropy fields and energies. We found that the simulation results captured the characteristic features of the experimentally observed data. We discuss the detail with the magnetization profiles of the component atoms. Furthermore, we investigated the effect of Dy random substitution on the coercivity in two systems: one in contact with vacuum and the other in contact with a grain boundary phase. We found that the threshold fields increased almost linearly with the concentration of Dy atoms in both systems, which was compared to the results of the layer-by-layer substitution effect analyzed in our previous work. We discuss the influence of the arrangement of Dy atoms on coercivity enhancement.
Characteristics of intense winds with significant variability in a mountainous valley of the Tibetan Plateau based on field measurement
Authors: Su Yanwen , Han Guowen , Cheng Xu , Zeng Yongping
Published: July 2024

Due to the influence of local complex topography and local severe convective weather system, wind events measured in mountainous valleys exhibit significant variability, that is, wind speed and wind direction often change rapidly in a short duration, which can pose a serious risk to the safety of many wind-sensitive infrastructures. However, the characteristics of steady winds in the atmospheric boundary layer have attracted extensive attention, but research on wind events with significant variability in mountainous valleys is still very insufficient. Therefore, based on the long-term wind field data collected by ultrasonic anemometer in a typical mountain valley of the Tibetan Plateau, the wind characteristics of these special wind events are comprehensively investigated. First of all, an effective quantifying approach is established to evaluate the variability levels based on the proposed spread metrics in statistics, which enables the identification of wind events with significant variability from the measured datasets. Furthermore, with the aim of obtaining turbulence components in three directions, and time-varying means to describe the trends of wind speed, wind direction, and angle of attack, an analysis strategy based on the moving average is presented. Finally, the mean characteristics and turbulence characteristics are investigated and compared with the steady wind events. The outcome of this study is expected to enhance the understanding of these special wind events and provide valuable reference for wind–structure interaction analysis in mountainous valleys.
Geometry-induced friction at a soft interface
Authors: Chawla Aashna , Kumar Deepak
Published: July 2024

Soft and biological matter come in a variety of shapes and geometries. When soft surfaces that do not fit into each other due to a mismatch in Gaussian curvatures form an interface, beautiful geometry-induced patterns are known to emerge. In this paper, we study the effect of geometry on the dynamical response of soft surfaces moving relative to each other. Using a simple experimental scheme, we measure friction between a highly bendable thin polymer sheet and a hydrogel substrate. At this soft and low-friction interface, we find a strong dependence of friction on the relative geometry of the two surfaces—a flat sheet experiences significantly larger friction on a spherical substrate than on flat or cylindrical substrate. We show that the stress developed in the sheet due to its geometrically incompatible confinement is responsible for the enhanced friction. This mechanism also leads to a transition in the nature of friction as the sheet radius is increased beyond a critical value. Our finding reveals a hitherto unnoticed mechanism based on an interplay between geometry and elasticity that may influence friction significantly in soft, biological, and nanoscale systems. In particular, it provokes us to reexamine our understanding of phenomena such as the curvature dependence of biological cell mobility.
Strain-induced enhancement of surface self-diffusion on strontium titanate (001) surfaces
Authors: Gueckelhorn D , Kersch A , Ruediger A
Published: July 2024

We present a numerical investigation of self-diffusion on strontium titanate TiO2-terminated (001) surfaces via density functional theory. Our calculations first indicate that Ti has the highest diffusion barrier with approximately 2.20 eV, thus representing the rate-limiting step for surface self-diffusion. Furthermore, the higher energy barriers of O and Ti in comparison to O2 and TiO2 indicate electronic activity with the surface atoms. Under the consideration of equi-biaxial strain as it would be encountered in e.g. heteroepitaxial thin films, the diffusion barriers for surface self-diffusion decrease for both compressive and tensile strains between −6% and 2%. For larger strains, we observe plastic deformations. This possibility to lower the energy barrier paves the way for accelerated and possible new mechanisms of surface diffusion and reconstruction of strontium titanate structures in a wide range of applications.
Transfer learning-based channel attention enhancement network combined with Gramian angular domain field for fault diagnosis
Authors: Hou Dongxiao , Mu Jintao , Zhang Bo , Chen Jiahui , Shi Peiming , Yan Shuang
Published: July 2024

Convolutional neural networks are increasingly used in the field of fault diagnosis, in order to give full play to the performance of the network within a certain number of model layers. While ensuring a high diagnostic accuracy, with strong generalization performance. We proposed a method that is simple, but effective. In this paper, we design a network structure for channel attention enhancement based on transfer learning (TL). The low-level is combined with TL to extract generic features of the target domain, and the high-level use a more refined channel attention module to extract and filter the abstract features of the current task object. The structure can fully exploit the fault information without increasing the network depth. Combined with Gramian angular difference field (GADF) to encode the vibration signal into 2D images as the input of the training model for fault diagnosis of rolling bearings. Source and target domains in TL uniformly use GADF encoded maps, effectively reducing the need for labeled samples. In order to validate the effectiveness of the method proposed in this paper, experiments were conducted using two publicly available bearing fault datasets and one laboratory-collected data, respectively. The results show that the proposed method is suitable for fault diagnosis of bearings in complex operating conditions and is highly generalizable.
Resolving crystallographic geometrically necessary dislocations in three dimensions in a hexagonal close packed titanium alloy
Authors: Witzen Wyatt A , Lamb James D , Arul Kumar Mariyappan , Echlin McLean P , Pollock Tresa M , Beyerlein Irene J
Published: July 2024

Geometrically necessary dislocation (GND) content is measured from mm3-scaled Ti7Al three-dimensional (3D) microstructural data using a theory extended for hexagonal close packed crystals, which accounts for basal, prismatic and pyramidal

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type dislocation content. The Ti7Al samples have been mechanically pre-strained to two different strain levels, and will then be strained along the same axis in uniaxial tension during simulation. Both inter- and intragranular GNDs across the microstructures have been characterized, with a large contribution of pyramidal

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GNDs, consistent with the relative slip activity involved in pre-straining. The spatially resolved crystallographic GND distributions within the 3D microstructures are used to instantiate a microstructure model for forward modeling deformation simulations by a dislocation density hardening elasto-viscoplastic fast Fourier transform framework. Coarsening the voxel resolution during the initial microstructure construction procedure is shown to strongly impact both the magnitude and spatial distribution of the GNDs and in turn the forward deformation response of the pre-strained material. This study indicates that the voxel resolution desired when transferring from measured to model microstructures need not only be proportionally scaled with the microstructure but also sufficiently fine to capture the subgranular orientation gradients that may already be present in the material.