bluuebunny/crossref_metadata_2025 huggingface dataset:
Can German Health Insurance Claims Data Fill Information Gaps in Rare Chronic Diseases: Use Case of Haemophilia A
Authors: Kratzer Vanessa , Rölz Verena , Bidlingmaier Christoph , Klamroth Robert , Behringer Jochen , Schramm Anja , Mansmann Ulrich , Berger Karin
Published: July 2024

Claims data are increasingly discussed to evaluate health care for rare diseases (resource consumption, outcomes and costs). Using haemophilia A (HA) as a use case, this analysis aimed to generate evidence for the aforementioned information using German Statutory Health Insurance (SHI) claims data. Claims data (2017–2019) from the German SHI ‘AOK Bayern - Die Gesundheitskasse’ were used. Patients with ICD-10-GM codes D66 and HA medication were included in descriptive analyses. Severity levels were categorized according to HA medication consumption. In total, 257 patients were identified: mild HA, 104 patients (mean age: 40.0 years; SD: 22.9); moderate HA, 17 patients, (51.2 years; SD: 24.5); severe HA, 128 patients, (34.2 years; SD: 18.5). There were eight patients categorized with inhibitors (37.8 years; SD: 29.6). Psychotherapy was reported among 28.8% (mild) to 32.8% (severe) of patients. Joint disease was documented for 46.2% (mild) to 61.7% (severe) of patients. Mean direct costs per patient per year were 1.34× for mild, 11× for moderate, 81× higher for severe HA patients and 223× higher for inhibitor patients than the mean annual expenditure per AOK Bayern insurant (2019). German SHI data provide comprehensive information. The patient burden in HA is significant with respect to joint disease and psychological stress regardless of the HA severity level. The cost of HA care for patients is high. Large cost ranges suggest that the individual situation of a patient must be considered when interpreting costs. The main limitation of SHI data analysis for HA was the lack of granularity of ICD codes.
Pathophysiologie und Diagnostik der Immunthrombozytopenie
Authors: Giagounidis Aristoteles
Published: July 2024

Die Immunthrombozytopenie (ITP) entsteht durch Autoantikörper-Bildung gegen Oberflächenantigene der Blutplättchen. Die Erkrankung tritt als primäre ITP ohne eindeutigen Auslöser oder als sekundäre ITP (Medikamente, andere Krankheitsbilder) auf. Die Autoantikörper-Bildung führt zu einem Verlust von Thrombozyten in Milz oder Leber und reduziert daneben auch die Bildung von Thrombozyten. Die Synthese von Thrombopoetin ist bei ITP-Patienten – im Gegensatz anderen Bildungsstörungen der Thrombozyten – reduziert. Die ITP ist eine Ausschlussdiagnose, beweisende Laboruntersuchung liegen nicht vor. Nur in 50% der Fälle lassen sich Glykoprotein-spezifische Antikörper nachweisen. Von besonderer Bedeutung ist der Ausschluss der EDTA-induzierten Pseudothrombozytopenie. Andere Ursachen der Thrombozytopenie sollten durch (Medikamenten-)Anamnese, körperliche Untersuchung und gegebenenfalls Knochenmarkpunktion ausgeschlossen werden.
Dynamics of Business Models in Circular Economy: Shifting Challenges in Pilot Projects
Authors: Lauten-Weiss J. , Friege H. , Westphal I. , Brinker J.
Published: July 2024

This study investigates the dynamics of circular business models (CBMs) through a multiple case study of 12 pilot projects funded by the German Federal Ministry of Education and Research between 2019 and 2022. The aim of this study was to draw practical conclusions for CBM pilot projects and public funding tenders, as well as to reveal theoretical insights into the motivation, perceptions of challenges, and potentials regarding CBMs and their shifts over time. Focused on remanufacturing and product-service systems (PSS), the study reveals significant shifts in motivation and perceived challenges before and after the pilot projects. Post-pilot, financial considerations emerged as a primary motivator for CBM adoption, alongside market pull factors and resource availability. However, challenges such as cost-related issues, supply chain complexities, and internal realignment hurdles persisted. Conversely, the perception of market-related challenges had decreased after the pilots, suggesting a growing readiness and adaptability of the market to CBMs. Similarly, experience-related challenges saw a decline, indicating an improvement in knowledge and capabilities within consortia over time. Moreover, the study examines shifts in perceived potential, revealing heterogeneous outcomes across different types of CBMs. While some projects identified new possibilities for value chain cooperation and transparency, others expressed skepticism about further potential, particularly in PSS-focused pilots. This study contributes to the growing body of literature on CBMs by providing empirical insights into the dynamics of circular economy (CE) pilot projects and their impact on organizational learning.
Crowned dens syndrome: Die Krone der
Kristallarthropathien
Authors: Schulz Nils , Lange Uwe , Klemm Philipp
Published: July 2024

Ziel Dieser Fallbericht soll das Bewusstsein für das seltene Crowned Dens
Syndrom (CDS) als unterdiagnostizierte Entität der Kristallarthropathie schärfen
und zur Verbesserung der Versorgungssituation beitragen in dem er Diagnose- und
Therapiestrategien diskutiert.

Methoden Es wird der Fall einer 68-jährigen Patientin mit CDS vorgestellt,
bei der eine Chondrokalzinose vorlag und rezidivierende Arthralgien bestanden.
Die Patientin verspürte Schmerzen insbesondere bei Rotationsbewegung des Kopfes
und präsentierte sich initial subfebril mit laborchemisch erhöhter
Entzündungsserologie.

Ergebnisse Mittels CT und Röntgenbildgebung konnte ein CDS diagnostiziert
und von anderen Differenzialdiagnosen abgegrenzt werden. Eine Meningitis konnte
mittels Lumbalpunktion ausgeschlossen werden. Unter eingeleiteter Therapie mit
Prednisolon und Ibuprofen besserten sich die Symptome der Patientin rasch. Vier
Wochen nach der Entlassung war die Patientin symptomfrei, mit normalen
Entzündungswerten und erfolgreicher Reduktion der Steroiddosis.

Fazit CDS sollte beim älteren Patienten mit akuten Nacken-/Kopfschmerzen
mit Steifheit und Fieber in Betracht gezogen werden insbesondere nach Ausschluss
einer entzündlich-rheumatischen, vaskulären und infektiösen Genese. Die Diagnose
wird mittels CT gesichert. Die Therapie erfolgt rein symptomatisch und besteht
aus Prednisolon und nichtsteroidalen Antirheumatika und führt in der Regel zu
einer schnellen Symptomlinderung. Eine Anfallsprophylaxe mit niedrigdosiertem
Colchizin kann durchgeführt werden.
Novel Insights into the Aortic Mechanical Properties of Mice Modeling Hereditary Aortic Diseases
Authors: Dubacher Nicolo , Sugiyama Kaori , Smith Jeffrey D. , Nussbaumer Vanessa , Csonka Máté , Ferenczi Szilamér , Kovács Krisztina J. , Caspar Sylvan M. , Lamberti Lisa , Meienberg Janine , Yanagisawa Hiromi , Sheppard Mary B. , Matyas Gabor
Published: July 2024

Objective Hereditary aortic diseases (hADs) increase the risk of aortic dissections and ruptures. Recently, we have established an objective approach to measure the rupture force of the murine aorta, thereby explaining the outcomes of clinical studies and assessing the added value of approved drugs in vascular Ehlers–Danlos syndrome (vEDS). Here, we applied our approach to six additional mouse hAD models.

Material and Methods We used two mouse models (Fbn1C1041G
and Fbn1mgR
) of Marfan syndrome (MFS) as well as one smooth-muscle-cell-specific knockout (SMKO) of Efemp2 and three CRISPR/Cas9-engineered knock-in models (Ltbp1, Mfap4, and Timp1). One of the two MFS models was subjected to 4-week-long losartan treatment. Per mouse, three rings of the thoracic aorta were prepared, mounted on a tissue puller, and uniaxially stretched until rupture.

Results The aortic rupture force of the SMKO and both MFS models was significantly lower compared with wild-type mice but in both MFS models higher than in mice modeling vEDS. In contrast, the Ltbp1, Mfap4, and Timp1 knock-in models presented no impaired aortic integrity. As expected, losartan treatment reduced aneurysm formation but surprisingly had no impact on the aortic rupture force of our MFS mice.

Conclusion Our read-out system can characterize the aortic biomechanical integrity of mice modeling not only vEDS but also related hADs, allowing the aortic-rupture-force-focused comparison of mouse models. Furthermore, aneurysm progression alone may not be a sufficient read-out for aortic rupture, as antihypertensive drugs reducing aortic dilatation might not strengthen the weakened aortic wall. Our results may enable identification of improved medical therapies of hADs.
Point-of-Care Testing in Patients with Hereditary Disorders of Primary Hemostasis: A Narrative Review
Authors: Bavinck Aernoud P. , Heerde Waander van , Schols Saskia E.M.
Published: July 2024

Inherited disorders of primary hemostasis, such as von Willebrand disease and congenital platelet disorders, can cause extensive, typically mucocutaneous bleeding. Assays to diagnose and monitor these disorders, such as von Willebrand factor activity assays and light transmission aggregometry, are performed in specialized hemostasis laboratories but are commonly not available in local hospitals. Due to the complexity and relative scarcity of these conventional assays, point-of-care tests (POCT) might be an attractive alternative in patients with hereditary bleeding disorders. POCTs, such as thromboelastography, are increasingly used to assess hemostasis in patients with acquired hemostatic defects, aiding clinical decision-making in critical situations, such as during surgery or childbirth. In comparison, the use of these assays in patients with hereditary hemostasis defects remains relatively unexplored. This review aims to give an overview of point-of-care hemostasis tests in patients with hereditary disorders of primary hemostasis. A summary of the literature reporting on the performance of currently available and experimental POCTs in these disorders is given, and the potential utility of the assays in various use scenarios is discussed. Altogether, the studies included in this review reveal that several POCTs are capable of identifying and monitoring severe defects in the primary hemostasis, while a POCT that can reliably detect milder defects of primary hemostasis is currently lacking. A better understanding of the strengths and limitations of POCTs in assessing hereditary defects of primary hemostasis is needed, after which these tests may become available for clinical practice, potentially targeting a large group of patients with milder defects of primary hemostasis.
The politics of pro-outsider labour market reforms: a configurational study
Authors: Marques Paulo , Branco Rui , Guimarães Rita
Published: July 2024

Over the past decades, the level of regulation of fixed-term contracts has been in flux. Many reforms deregulating these contracts were followed by a regulatory countertrend, a puzzling finding considering influential theoretical expectations like the ones developed by the dualization and liberalization literatures. This paper draws on the comparative employment relations and comparative political economy literatures to identify the drivers of pro-outsider reforms. Furthermore, it develops an innovative argument claiming that governments may rely on support from a ‘domestic coalition’ including workers in permanent contracts, or they can leverage the European link to support their intention of conducting a pro-outsider reform. Each of these paths relies on the assemblage of distinct pro-reform coalitions of policy actors. To test our argument, the paper uses fsQCA. We compare 38 reforms enacted in 16 European countries between 1985–2019. After the fsQCA analysis, we conduct a qualitative discussion of the different paths.
Temporal coupled-mode theory in nonlinear resonant photonics: From basic principles to contemporary systems with 2D materials, dispersion, loss, and gain
Authors: Christopoulos Thomas , Tsilipakos Odysseas , Kriezis Emmanouil E.
Published: July 2024

Temporal coupled-mode theory (CMT) is an acclaimed and widely used theoretical framework for modeling the continuous-wave response and temporal dynamics of any integrated or free-space photonic resonant structure. It was initially employed to understand how energy is coupled into and out of a cavity and how it is exchanged between different resonant modes. In the 30 years that followed its establishment, CMT has been expanded to describe a broad range of nonlinear interactions as well (self- and cross-phase modulation, saturable absorption, frequency generation, gain, etc.). In this Tutorial, we thoroughly present the basic principles and the evolution of CMT throughout the years, showcasing its immense capabilities for the analysis and design of linear and nonlinear resonant photonic systems. Importantly, we focus on the examples of modern, open nanophotonic resonators incorporating contemporary bulk or sheet (2D) materials that may be lossy and dispersive. For each linear/nonlinear effect under study, we follow a meticulous, step-by-step approach, starting from an accurate model of the physical phenomenon and proceeding to its introduction in the CMT framework all the way to the efficient solution of the resulting system of equations. Our work highlights the merits of CMT as an efficient, accurate, and versatile theoretical tool. We envision that it can serve both as an introductory reference for any reader and as a comprehensive handbook on how to incorporate a broad range of linear and nonlinear effects in the CMT framework.
Floquet isospectrality of the zero potential for discrete periodic Schrödinger operators
Authors: Faust Matthew , Liu Wencai , Matos Rodrigo , Plute Jenna , Robinson Jonah , Tao Yichen , Tran Ethan , Zhuang Cindy
Published: July 2024

Let Γ=q1Z⊕q2Z⊕⋯⊕qdZ, with qj∈Z+ for each j ∈ {1, …, d}, and denote by Δ the discrete Laplacian on ℓ2Zd. Using Macaulay2, we first numerically find complex-valued Γ-periodic potentials V:Zd→C such that the operators Δ + V and Δ are Floquet isospectral. We then use combinatorial methods to validate these numerical solutions.
Interfacial modification strategies to secure phase-stability for inorganic perovskite solar cells
Authors: Lee Hyong Joon , Heo Jin Hyuck , Im Sang Hyuk
Published: July 2024

The rapid success achieved from perovskite solar cell has drawn great expectations for commercialization of next-generation photovoltaics. Among the various perovskite materials, the inorganic perovskite derivatives have been of particular interest, ascribed to its superior thermal and chemical stability, which is a crucial criterion for reliable long-term operation. Nonetheless, the development of the efficient inorganic perovskite solar cells has been lagged from its organic–inorganic hybrid counterparts owing to the notorious phase-stability challenges associated with the formation of non-photoactive phases. The early progress of the inorganic perovskite solar cells has been centered on the stable perovskite phase-preparation and leads to the effective bulk management through intermediate engineering and compositional engineering strategies. Yet, challenges remain in securing the as-formed perovskite phase throughout the long-term operation. Accordingly, recent studies find interfacial modification strategies successful by constricting the phase-transformation channels in various perspectives such as defect propagation, strain, component segregation, charge accumulation, and external stresses. In this review, we start with the brief description on the inorganic perovskite solar cells and the associated advantages including chemical and optoelectronic properties. We then provide a review on the challenges of inorganic perovskite solar cells associated with the phase instabilities. We elaborate on the origins of the phase instabilities in terms of thermodynamics and the recently proposed channels including intrinsic factors and extrinsic factors that facilitate the detrimental phase transformation. Finally, we survey the recent successful approaches to stabilize the inorganic perovskite solar cells through interface managements and provide outlook on further progress.
Effect of ion irradiation on superconducting thin films
Authors: Kohopää Katja , Ronzani Alberto , Jabdaraghi Robab Najafi , Bera Arijit , Ribeiro Mário , Hazra Dibyendu , Senior Jorden , Prunnila Mika , Govenius Joonas , Lehtinen Janne S. , Kemppinen Antti
Published: July 2024

We demonstrate ion irradiation by argon or gallium as a wafer-scale post-processing method to increase disorder in superconducting thin films. We study several widely used superconductors, both single-elements and compounds. We show that ion irradiation increases normal-state resistivity in all our films, which is expected to enable tuning their superconducting properties, for example, toward a higher kinetic inductance. We observe an increase in superconducting transition temperature for Al and MoSi and a decrease for Nb, NbN, and TiN. In MoSi, ion irradiation also improves the mixing of the two materials. We demonstrate the fabrication of an amorphous and homogeneous film of MoSi with uniform thickness, which is promising, for example, for superconducting nanowire single-photon detectors.
Atomistic insights into the reentrant phase-transitions in polyuracil and polylysine mixtures
Authors: Ramachandran Vysakh , Potoyan Davit A
Published: July 2024

The phase separation of protein and RNA mixtures underpins the assembly and regulation of numerous membraneless organelles in cells. The ubiquity of protein–RNA condensates in cellular regulatory processes is in part due to their sensitivity to RNA concentration, which affects their physical properties and stability. Recent experiments with poly-cationic peptide–RNA mixtures have revealed closed-loop phase diagrams featuring lower and upper critical solution temperatures. These diagrams indicate reentrant phase transitions shaped by biomolecular interactions and entropic forces such as solvent and ion reorganization. We employed atomistic simulations to study mixtures with various RNA–polylysine stoichiometries and temperatures to elucidate the microscopic driving forces behind reentrant phase transitions in protein–RNA mixtures. Our findings reveal an intricate interplay between hydration, ion condensation, and specific RNA–polylysine hydrogen bonding, resulting in distinct stoichiometry-dependent phase equilibria governing stabilities and structures of the condensate phase. Our simulations show that reentrant transitions are accompanied by desolvation around the phosphate groups of RNA, with increased contacts between phosphate and lysine side chains. In RNA-rich systems at lower temperatures, RNA molecules can form an extensive pi-stacking and hydrogen bond network, leading to percolation. In protein-rich systems, no such percolation-induced transitions are observed. Furthermore, we assessed the performance of three prominent water force fields—Optimal Point Charge (OPC), TIP4P-2005, and TIP4P-D—in capturing reentrant phase transitions. OPC provided a superior balance of interactions, enabling effective capture of reentrant transitions and accurate characterization of changes in solvent reorganization. This study offers atomistic insights into the nature of reentrant phase transitions using simple model peptide and nucleotide mixtures. We believe that our results are broadly applicable to larger classes of peptide–RNA mixtures exhibiting reentrant phase transitions.
Ion association behaviors in the initial stage of calcium carbonate formation: An ab initio study
Authors: Li Yue , Zhang Jiarui , Zeng Hongbo , Zhang Hao
Published: July 2024

In this work, we performed static density functional theory calculations and ab initio metadynamics simulations to systematically investigate the association mechanisms and dynamic structures of four kinds of ion pairs that could be formed before the nucleation of CaCO3. For Ca2+–HCO3− and Ca2+–CO32− pairs, the arrangement of ligands around Ca2+ evolves between the six-coordinated octahedral structure and the seven-coordinated pentagonal bipyramidal structure. The formation of ion pairs follows an associative ligand substitution mechanism. Compared with HCO3−, CO32− exhibits a stronger affinity to Ca2+, leading to the formation of a more stable precursor phase in the prenucleation stage, which promotes the subsequent CaCO3 nucleation. In alkaline environments, excessive OH− ions decrease the coordination preference of Ca2+. In this case, the formation of Ca(OH)+–CO32− and Ca(OH)2–CO32− pairs favors the dissociative ligand substitution mechanism. The inhibiting effects of OH− ion on the CaCO3 association can be interpreted from two aspects, i.e., (1) OH− neutralizes positive charges on Ca2+, decreases the electrostatic interactions between Ca2+ and CO32−, and thus hinders the formation of the CaCO3 monomer, and (2) OH− decreases the capacity of Ca2+ for accommodating O, making it easier to separate Ca2+ and CO32− ions. Our findings on the ion association behaviors in the initial stage of CaCO3 formation not only help scientists evaluate the impact of ocean acidification on biomineralization but also provide theoretical support for the discovery and development of more effective approaches to manage undesirable scaling issues.
Absolute thickness field measurement on curved axisymmetric thin free films with monochromatic light
Authors: Miguet J. , Bussonnière A.
Published: July 2024

The thickness of thin films is a key parameter to understand their thinning dynamics and stability. Thickness measurements are commonly performed using interferometry. White light illumination allows us to measure the absolute thickness, but is limited to small thicknesses (<2μm) or is restricted to a point with a spectrometer. Monochromatic light gives access to a broader range of thicknesses but solely in a relative manner unless a reference thickness is known. These methods are extensively used to quantify the thickness profiles of flat soap films. In contrast, they are applied to curved interfaces (bubbles) only in a few specific cases, mainly due to the complexity arising from the curvature as the optical path depends on the position. In this paper, we elucidate the influence of the curvature and show that it can be used to measure the entire and absolute thickness profiles using monochromatic light. We demonstrate the validity of the method on soap bubbles, antibubbles, and catenoid soap films. This cost-effective technique is adapted to quantitatively study the thin film dynamics in these geometries.
Deep insight on Li interlayer migration in O3-type NaLi1/3Mn2/3O2 as a cathode material for Na-ion batteries
Authors: Qin Wenjing , Li Mei , Sun Baozhen , Wu Musheng , Liu Sanqiu , Xu Bo
Published: July 2024

Layered manganese transition metal oxides, such as NaMnO2, have attracted great interest due to the low cost and high capacity. However, complex phase transitions in NaMnO2 lead to poor cycling stability. The introduction of Li doping has been confirmed to improve the performance of NaMnO2. O3-type NaLi1/3Mn2/3O2 (NLMO), synthesized in 2021, has demonstrated excellent electrochemical performance. Notably, irreversible Li interlayer migration (Li migrates from the transition metal layer to the alkali metal layer) has been observed during cycling, which is related to the electrochemical performance. Therefore, it is crucial to understand the mechanism underlying Li interlayer migration in O3-NLMO. However, the environment of Li interlayer migration on cycling is complex and involves interlayer spacing, Na-ion concentration, the degree of O-ion oxidation, and phase transition. Here, in this work, we utilized the first-principles method to decouple the coupling factors influencing the Li interlayer migration. Through analyzing the impact of the single-factor on Li interlayer migration, we aim to identify the crucial factors affecting this process. Our results show that a decrease in Na-ion concentration and an increase in O-ion oxidation degree promote the Li interlayer migration, while the O–P phase transition suppresses the Li interlayer migration. Interlayer spacing was found to play a less influential role in Li interlayer migration. Our investigations provide effective strategies for the subsequent regulation of Li interlayer migration.
Self-immunity study of quadrotor UAV based on Modelica system modeling and disturbance feed-forward compensation
Authors: Xiaopeng Bao , Zhou Hao , Tan Siwei
Published: July 2024

For addressing the challenges of decreased attitude and trajectory tracking accuracy and a delayed response in the flight control operations of quadcopter unmanned aerial vehicles (UAVs) under the uncertainties of model parameters and external disturbances, this study leverages the advantages of the non-causal declarative modeling language Modelica in system modeling and simulation. In addition, it incorporates the nonlinear Active Disturbance Rejection Control (ADRC) framework for disturbance observation, estimation, and compensation. A state observer is designed to mitigate the impact of external disturbances and model uncertainties through feed-forward compensation, and stability analysis is conducted. Numerical simulations for hover resistance demonstrate that, compared to the cascade proportional integral differential (PID) control strategy, PID-NLADRC reduces the maximum deviation induced by wind disturbances by ∼50% and shortens the disturbance influence time by around 40%. Simulations for different trajectories, such as planar or spatial, smooth or abrupt changes, indicate that under the PID-NLADRC control strategy, the real-time spatial distance deviation mean is reduced by 69.5%, and the peak time is shortened by 75.7%. Validation through multi-objective applications and physical experiments highlights the advantages of PID-NLADRC in terms of positioning accuracy, rapid tracking, and disturbance suppression, aligning well with the fast, precise, and robust flight control requirements of quadcopter UAVs.
Hyperfine interactions for small systems including transition-metal elements using self-interaction corrected density-functional theory
Authors: Karanovich Anri , Jackson Koblar Alan , Park Kyungwha
Published: July 2024

The interactions between the electronic magnetic moment and the nuclear spin moment, i.e., magnetic hyperfine (HF) interactions, play an important role in understanding electronic properties of magnetic systems and in realizing platforms for quantum information science applications. We investigate the HF interactions for atomic systems and small molecules, including Ti or Mn, by using Fermi–Löwdin orbital (FLO) based self-interaction corrected (SIC) density-functional theory. We calculate the Fermi contact (FC) and spin-dipole terms for the systems within the local density approximation (LDA) in the FLO-SIC method and compare them with the corresponding values without SIC within the LDA and generalized-gradient approximation (GGA), as well as experimental data. For the moderately heavy atomic systems (atomic number Z ≤ 25), we find that the mean absolute error of the FLO-SIC FC term is about 27 MHz (percentage error is 6.4%), while that of the LDA and GGA results is almost double that. Therefore, in this case, the FLO-SIC results are in better agreement with the experimental data. For the non-transition-metal molecules, the FLO-SIC FC term has the mean absolute error of 68 MHz, which is comparable to both the LDA and GGA results without SIC. For the seven transition-metal-based molecules, the FLO-SIC mean absolute error is 59 MHz, whereas the corresponding LDA and GGA errors are 101 and 82 MHz, respectively. Therefore, for the transition-metal-based molecules, the FLO-SIC FC term agrees better with experiment than the LDA and GGA results. We observe that the FC term from the FLO-SIC calculation is not necessarily larger than that from the LDA or GGA for all the considered systems due to the core spin polarization, in contrast to the expectation that SIC would increase the spin density near atomic nuclei, leading to larger FC terms.
Implementation and validation of a generalized wall stress function
Authors: Xue K. , Quosdorf D. , Zhao L. , Manhart M.
Published: July 2024

The generalized wall function by Shih et al. [Report No. M-1999-209398 (1999)], which accounts for non-equilibrium effects by the presence of favorable and adverse pressure gradients in turbulent flows, is addressed with the aim of performing high Reynolds number large-eddy simulations of the wall-bounded flow. The model uses a corrected law of the wall with a pressure gradient contribution to approximate the wall stress and applies to the entire viscous layer, buffer layer, and inertial region. A fully developed channel flow is first tested to validate the solver and model implementation, and then the wall function is assessed for the flow over a periodic hill. Wall-resolved simulations are in good agreement with reference results. A priori investigation with own experimental results corroborates the mathematical form of the model and suggests using different coefficients. The wall-modeled simulations show that the implemented wall model is able to improve the wall shear stress predictions compared to a standard equilibrium wall model. It corrects the underestimation of wall shear stresses by equilibrium models in the favorable pressure gradient region and the overestimation of wall shear stresses in the adverse pressure gradient region. The positions of the separation and reattachment points are also in good agreement with reference results. Furthermore, the prediction of the wall shear stress maximum in the favorable pressure gradient zone at the windward side of the hill is quite robust against coarsening the wall-normal grid spacing.
Turbulent flow inside a cubic lid-driven cavity using moment representation lattice Boltzmann method
Authors: Ferrari M. A. , Franco A. T. , Hegele L. A.
Published: July 2024

The present work numerically models the flow inside a cubic lid-driven cavity for Reynolds numbers up to 100 000 using the lattice Boltzmann method. Stable results using the numerical method are obtained, with an implementation of a new set of moment equations for the Dirichlet boundary conditions, allowing approximately one order of magnitude increase in the maximum numerically stable Reynolds number for a given resolution. When evaluating the flow inside the cavity, the flow regime change occurred between Reynolds numbers 20 000 and 25 000, where the core of the turbulent dissipation moves from the bottom of the cavity toward the downstream wall. For Reynolds numbers higher than 50 000, the dissipation was localized near the moving lid. Additionally, negative turbulence production is observed in the bottom wall due to negative velocity gradients caused by the Taylor–Görtler-like vortex colliding with the bottom of the cavity.
Design of a compact coaxial distributed intense relativistic electron beam focusing system
Authors: Yan Ruixia , Ling Junpu , He Yufang , Xu Weili , Zeng Fanbo , He Juntao
Published: July 2024

In order to achieve the objectives of compactness and miniaturization in high-power microwave systems, along with reducing system energy consumption, this paper presents a design of a compact coaxial distributed intense relativistic electron beam (IREB) focusing system based on the transit time oscillator. The design methodology integrates theoretical analysis with a 2.5-dimensional particle simulation method. The entire IREB focusing system is composed of three sets of distributed magnetic rings and front-end focusing structures. The layout of this magnetic system is optimized based on periodic permanent magnets, leading to the formation of a quasi-trapezoidal wave magnetic field configuration. This optimization reduces the required number of magnetic rings while ensuring the efficient transmission of the IREB. To prevent the breakdown of the loaded magnetic rings and to optimize the radial electric field in the diode region, an additional front-end focusing structure was added. Based on the aforementioned structural configuration, a 100% electron beam transmission rate was achieved within a 150 mm range.
Steering opinion dynamics through control of social networks
Authors: Nugent A. , Gomes S. N. , Wolfram M. T.
Published: July 2024

In this paper, we propose a novel control approach for opinion dynamics on evolving networks. The controls modify the strength of connections in the network, rather than influencing opinions directly, with the overall goal of steering the population toward a target opinion. This requires that the social network remains sufficiently connected, the population does not break into separate opinion clusters, and that the target opinion remains accessible. We present several approaches to address these challenges, considering questions of controllability, instantaneous control, and optimal control. Each of these approaches provides a different view on the complex relationship between opinion and network dynamics and raises interesting questions for future research.
Spontaneous convective pattern formation in a dusty plasma
Authors: Dhaka Ankit , Bandyopadhyay P. , Subhash P. V. , Sen A.
Published: July 2024

We report on experimental observations of self-sustaining convective patterns in a dusty plasma system. The experiments are carried out in a capacitively coupled radio frequency (RF) argon plasma discharge in which a dusty plasma is produced by introducing micrometer-sized melamine formaldehyde particles. A self-sustained pair of convective cells with opposite vorticities is seen to appear in a lateral view of the system, beyond some threshold values of the background gas pressure and RF power. Particle tracking velocimetry measurements reveal the existence of a dust temperature gradient that is responsible for the convective counter-rotating patterns. The origin of the kinetic temperature gradient in the absence of any external heat source is attributed to the larger ion flux induced heating of the bottom layer of the dust cloud. The velocity and vorticity of the particles in the convective cell increase with an increase in the vertical kinetic temperature gradient. The experimental results compare reasonably well with the findings of molecular dynamics simulations of the laboratory system.
Probing the structural evolution on the surface of cardiolipin vesicles with an amphiphilic second harmonic generation and fluorescence probe
Authors: Chen Shujiao , Liu Zhongcheng , Li Bifei , Hou Yi , Peng Yingying , Li Jianhui , Yuan Qunhui , Gan Wei
Published: July 2024

Investigating the influence of the ambient chemical environment on molecular behaviors in liposomes is crucial for understanding and manipulating cellular vitality as well as the capabilities of lipid drug carriers in various environments. Here, we designed and synthesized a second harmonic generation (SHG) and fluorescence probe molecule called Pyr-Py+-N+ (PPN), which possesses membrane-targeting capability. We employed PPN to investigate the response of lipid vesicles composed of cardiolipin to the presence of exogenous salt. The kinetic behaviors, including the adsorption and embedding of PPN on the surface of small unilamellar vesicles (SUVs) composed of cardiolipin, were analyzed. The response of the SUVs to the addition of NaCl was also monitored. A rapid decrease in vesicle size can be evidenced through the rapid drop in SHG emission originating from PPN located on the vesicle surface.
Soliton groups and extreme wave occurrence in simulated directional sea waves
Authors: Slunyaev A. V.
Published: July 2024

The evolution of nonlinear wave groups that can be associated with long-lived soliton-type structures is analyzed, based on the data of numerical simulation of irregular deep-water gravity waves with spectra typical to the ocean and different directional spreading. A procedure of the windowed Inverse Scattering Transform, which reveals wave sequences related to envelope solitons of the nonlinear Schrödinger equation, is proposed and applied to the simulated two-dimensional surfaces. The soliton content of waves with different directional spreading is studied in order to estimate its dynamical role, including characteristic lifetimes. Statistical features of the solitonic part of the water surface are analyzed and compared with the wave field on average. It is shown that intense wave patterns that persist for tens of wave periods can emerge in stochastic fields of relatively long-crested waves. They correspond to regions of locally enhanced on average waves with reduced kurtosis. This eventually leads to realization of locally extreme wave conditions compared to the general background. Although intense soliton-like groups may be detected in short-crested irregular waves as well, they possess much shorter lateral sizes, quickly disperse, and do not influence the local statistical wave properties.
Enhancing the dielectric constant of zwitterionic liquids via dipole moment and anion chemistry
Authors: Mei Wenwen , Colby Ralph H. , Hickey Robert J.
Published: July 2024

The dielectric constant is a critical parameter in many energy-related applications. Typically, increasing the dielectric constant of soft materials involves adding high dielectric constant polar liquids or inorganic fillers, but there are limitations to this approach due to safety concerns with volatile and flammable solvents and the agglomeration of inorganic fillers. An alternative approach is to add zwitterionic liquids that exhibit exceptionally high dielectric constants with negligible volatility. Here, we report the synthesis of a series of zwitterionic liquids containing an imidazolium cation, exhibiting the highest dielectric constant among all organic molecules (∼350 at 293 K). The cation–anion linkage was tailored in a wide range between three and nine carbons, rendering the zwitterion dipole from 25 to 52 D. Comparing the dielectric constant for zwitterions with different anions (i.e., sulfonylimide, sulfonate, and carboxylate) reveals the beneficial impacts of the delocalized sulfonylimide anion vs the carboxylate anion due to the enlarged molecular dipole and more homogenous liquid morphology. Molecular dipole and liquid morphology are identified as the keys to developing high dielectric constant zwitterionic liquids. The extremely high dielectric constant accessible with the proposed molecular design paves new avenues for developing high dielectric constant zwitterions that act as dielectricizers.
Thermal engineering increases current density in AlGaN/GaN superlattice devices
Authors: Pavlidis G. , Jamil M. S. , Myren D. , Keebaugh S. , Chang J. , Doerflein M. , Afroz S. , Howell R. S. , Centrone A.
Published: July 2024

Aluminum gallium nitride/gallium nitride multi-channel superlattice devices are receiving increasing attention as a new paradigm for driving the power density of gallium nitride based transistors toward their theoretical limit. However, the superior electrical performance of superlattice-based transistors is currently limited by excessive Joule-heating. This Letter evaluates what impact the number of superlattice channels and the buffer layer composition has on the reduction of the thermal resistance, i.e., Joule heating, of AlGaN/GaN superlattice devices. A record low thermal resistance (12.51 ± 0.34 K mm W−1) was measured via scanning thermal microscopy for non-castellated superlattice AlGaN/GaN devices with a 100 μm channel width. Overall, the use of a thin gallium nitride buffer layer, in place of a thick aluminum gallium nitride layer, reduced the buffer thermal resistance enabling the accommodation of more superlattice channels (10 vs 6), therefore augmenting the maximum power density of these devices. The superlattice device proposed here not only provides an enhanced thermal dissipation solution for high power density radio frequency electronics, but it also has the benefit of fewer fabrication steps in comparison with previously reported castellated multichannel devices.
Preparation of carbon/nickel composites by magnetron sputtering and study on electromagnetic shielding effectiveness
Authors: Zhang Yiwen , Fan Jingyi , Ji Peiyu , Li Maoyang , Tan Haiyun , Zhang Xiaoman , Huang Tianyuan , Wu Xuemei
Published: July 2024

A pure nickel film and a carbon/nickel (C/Ni) composite film were produced using radio frequency magnetron sputtering. The structure of the films was regulated by adjusting the sputtering power and the time allocation of sputtering nickel and graphite targets. Furthermore, a scanning electron microscope, an x-ray diffractometer, and a Raman spectrometer were employed for sample characterization. The results demonstrated that the thickness of the pure nickel film and C/Ni composite film with a total deposition time of 60 s was between 44.96 and 65.31 nm. The nickel film exhibited preferential growth along the crystal plane (111), and the structure of carbon materials was in the second stage of the three-stage model known as “amorphization trajectory of graphite.” The prepared films’ electromagnetic interference shielding effectiveness (EMI SE) in the X-band was investigated using a vector network analyzer. It was observed that the C/Ni composite film with a thickness of 44.96 nm demonstrated a superior EMI SE with a maximum value reaching 21 dB. The EMI SE of the C/Ni composite film can reach the same performance and even exceed that of the pure nickel film obtained at the power of 200 W for 60 s in certain frequency segments. In conclusion, the pure nickel film can be replaced by C/Ni composite film prospectively due to their excellent EMI SE along with advantages such as reduced thickness, lighter weight, and lower cost.
A fluorogenic complementation tool kit for interrogating lipid droplet–organelle interaction
Authors: Li Xiao , Gamuyao Rico , Wu Ming-Lun , Cho Woo Jung , King Sharon V. , Petersen R.A. , Stabley Daniel R. , Lindow Caleb , Climer Leslie K. , Shirinifard Abbas , Ferrara Francesca , Throm Robert E. , Robinson Camenzind G. , Zhou Yiwang , Carisey Alexandre F. , Tebo Alison G. , Chang Chi-Lun
Published: July 2024

Contact sites between lipid droplets and other organelles are essential for cellular lipid and energy homeostasis upon metabolic demands. Detection of these contact sites at the nanometer scale over time in living cells is challenging. We developed a tool kit for detecting contact sites based on fluorogen-activated bimolecular complementation at CONtact sites, FABCON, using a reversible, low-affinity split fluorescent protein, splitFAST. FABCON labels contact sites with minimal perturbation to organelle interaction. Via FABCON, we quantitatively demonstrated that endoplasmic reticulum (ER)- and mitochondria (mito)-lipid droplet contact sites are dynamic foci in distinct metabolic conditions, such as during lipid droplet biogenesis and consumption. An automated analysis pipeline further classified individual contact sites into distinct subgroups based on size, likely reflecting differential regulation and function. Moreover, FABCON is generalizable to visualize a repertoire of organelle contact sites including ER-mito. Altogether, FABCON reveals insights into the dynamic regulation of lipid droplet–organelle contact sites and generates new hypotheses for further mechanistical interrogation during metabolic regulation.
Kids’ noses resist COVID-19
Authors: Zanoni Ivan
Published: July 2024

Children resist COVID-19, and previous studies reported increased innate immunity in their upper airways. A new paper by Watkins et al. (https://doi.org/10.1084/jem.20230911) shows that the nasal mucosa of children is characterized by often asymptomatic viral and/or bacterial infections that dynamically regulate distinct innate immune programs.
Effect of Rare-Earth Element Substitution in Superconducting R3Ni2O7 under Pressure
Authors: Pan 潘 Zhiming 志明 , Lu 卢 Chen 晨 , Yang 杨 Fan 帆 , Wu 吴 Congjun 从军
Published: July 2024

Recently, high temperature (T
c ≈ 80 K) superconductivity (SC) has been discovered in La3Ni2O7 (LNO) under pressure. This raises the question of whether the superconducting transition temperature T
c could be further enhanced under suitable conditions. One possible route for achieving higher T
c is element substitution. Similar SC could appear in the Fmmm phase of rare-earth (RE) R3Ni2O7 (RNO, R = RE element) material series under suitable pressure. The electronic properties in the RNO materials are dominated by the Ni 3d orbitals in the bilayer NiO2 plane. In the strong coupling limit, the SC could be fully characterized by a bilayer single 3d

x
2–y
2
-orbital t–J
∥–J
⊥ model. With RE element substitution from La to other RE element, the lattice constant of the Fmmm RNO material decreases, and the resultant electronic hopping integral increases, leading to stronger superexchanges between the 3d

x
2–y
2
orbitals. Based on the slave-boson mean-field theory, we explore the pairing nature and the evolution of T
c in RNO materials under pressure. Consequently, it is found that the element substitution does not alter the pairing nature, i.e., the inter-layer s-wave pairing is always favored in the superconducting RNO under pressure. However, the T
c increases from La to Sm, and a nearly doubled T
c could be realized in SmNO under pressure. This work provides evidence for possible higher T
c R3Ni2O7 materials, which may be realized in further experiments.
Application of improved Wolf pack algorithm in planning and operation of multi-microgrid systems with electric vehicles
Authors: Sun Guohao , Zhang Shouming , Yang Sen , Zhao Yuhao
Published: July 2024

With the rapid growth of renewable energy sources and the widespread use of electric vehicles (EVs), the planning and operation problems of multiple microgrids (MMGs) have become more complex and diverse. This paper develop an MMG model with multiple renewable energy sources and small-scale EVs, aiming to maximize the use of renewable energy sources and realize the charging demand of EVs, and highlighting the potential role of EVs in MMGs. In addition, the paper underscores the indispensable role of measurement technology in microgrids and the impetus that microgrid development provides for advancements in measurement technology. To this end, this paper proposes an improved Wolf pack algorithm (IWPA) based on the standard Wolf Pack Algorithm (WPA) with a spiral search approach and chaotic updating of individuals to improve the global search capability of the algorithm and the complexity of solving the scheduling problem. Through simulation experiments on ten standard test functions and examples, it is verified that the IWPA algorithm improves the search accuracy by 2.8%–6.8% and 13.9%–18.3% in the worst and best cases, respectively, in comparison with other algorithms, and it also has a faster convergence speed. Meanwhile, this paper proposes a load interval pricing strategy for the shortcomings of time-of-use pricing strategy and traditional real-time pricing strategy, which is simulated under grid-connected operation, isolated grid operation, and multi-microgrid cooperative operation modes, and the simulation results of the arithmetic example show that this strategy can effectively reduce carbon emissions, and IWPA can effectively coordinate renewable energy, EVs, and other energy resources to achieve efficient energy management of MMGs and supply-demand balance.