bluuebunny/crossref_metadata_2025 huggingface dataset:
Gewalt in organisierten Gewaltstrukturen in der DDR – Eine
Sekundäranalyse von Anhörungen und Berichten aus
Betroffenenperspektive
Authors: Laue Philipp , Strauß Bernhard
Published: November 2024

Ziel der Studie Gewalt in organisierten Gewaltstrukturen (GOG) wird als
Form lang anhaltender, wiederholter, häufig sexualisierter Gewalt vor allem
gegenüber Kindern, Jugendlichen oder Frauen durch vernetzte Täter:innen zur
finanziellen und machtbezogenen Bereicherung verstanden. Nachdem vereinzelte
Betroffenenberichte und historische Analysen die Möglichkeit dieses
Gewaltphänomens vor dem zeitlichen und geografischen Hintergrund der DDR
implizierten, beleuchtet diese Studie erstmalig GOG in der DDR aus Sicht der
Betroffenen.

Methodik N=10 pseudonymisierte Anhörungen und schriftliche Berichte von
Betroffenen sexualisierter Gewalt im Kindes- und Jugendalter in der DDR, die
durch die Unabhängige Kommission zur Aufarbeitung sexuellen Kindesmissbrauchs
zur Verfügung gestellt waren, wurden mittels inhaltlich strukturierender
qualitativer Inhaltsanalyse sekundäranalytisch ausgewertet.

Ergebnisse Es fanden sich Berichte sexualisierter, physischer und
psychischer Gewaltanwendung. Die Betroffenen beschreiben GOG in verschiedenen
Kontexten, wobei weitere Kategorien (Täter:innen, Dauer/Häufigkeit der Gewalt,
Gewaltmotive) mitunter von diesen abhängig waren. Die Folgen für Betroffene sind
sowohl kurz- wie langfristiger Natur und zeigen sich verlaufen sowohl auf
gesundheitlicher (v. a. psychopathologischer) wie psychosozialer Ebene bis in
die Gegenwart. Abgesehen vom historischen Hintergrund fanden sich keine Hinweise
auf DDR-spezifische Merkmale des Gewaltphänomens.

Diskussion Die Erlebnisberichte von Betroffenen ermöglichen die
Perspektive des „erlebten Wissens“, welche ihre Grenze dort hat, wo
Beschreibungen das Wissen von Täter:innen (z. B. Gewaltmotive, Merkmale der
Gewaltstruktur) voraussetzen. Mögliche politisch-ideologische Merkmale der
Gewalt finden auch aufgrund der Betrachtung von GOG als „ideologiefreies“
Phänomen (im Gegensatz zu Ritueller Gewalt) keine Erörterung. Für eine
geschichtssensible Weiterführung von Forschung bedarf es neben definitorischer
Grenzziehungen unterschiedlicher Phänomene v. a. einer multiperspektivischen
sowie multiprofessionellen Herangehensweise.
Zentrumszuschläge für Endometriosezentren? Überprüfung der
Voraussetzungen gemäß der Zentrums-Regelungen vom Gemeinsamen Bundesausschluss
(G-BA)
Authors: Cirkel Christoph , Degen Hanna , Zimmermann Christiane , Schöffski Oliver , Rody Achim
Published: November 2024

Zentren und Schwerpunkte – z. B. Endometriosezentren (EZ) – übernehmen im
Gesundheitssystem wichtige Aufgaben, die nicht notwendigerweise über
Fallpauschalen oder Zusatzentgelte finanziert sind. Am 01.01.20 sind die
„Regelungen zur Konkretisierung der besonderen Aufgaben von Zentren und
Schwerpunkten gemäß §136c Abs. 5 SGB V“ vom G-BA in Kraft getreten. Sie bieten
die Grundlage für die Vereinbarung von Zentrumszuschlägen für die Wahrnehmung
von besonderen Aufgaben zwischen Kliniken und Leistungsträgern. Diese Arbeit
überprüft systematisch, ob und unter welchen Voraussetzungen die besonderen
Aufgaben von Stiftung Endometrioseforschung (SEF) zertifizierte EZ
zuschlagsberechtigt sind.

Im Ergebnis erfüllen SEF zertifizierte EZ allgemeine typische Zentrumsaufgaben,
jedoch fehlen EZ aktuell (politische) Voraussetzungen, die zur Erlangung von
Zentrumszuschlägen notwendig sind.
Impact of Insurance Status on Postoperative Recovery after Microsurgical Breast Reconstruction
Authors: Lu Yi-Hsueh , Rothchild Evan , Yan Yufan , Mahajan Lakshmi , Park Michelle , Ricci Joseph A.
Published: November 2024

Background Persistent disparities in breast reconstruction access have been widely documented, yet a significant research gap remains in understanding the impact of social determinants of health (SDOH) on postoperative outcomes and complications.

Methods A retrospective chart review was performed on all patients who underwent abdominal-based free-flap breast reconstruction between August 2018 and December 2022 at a racially, ethnically, and socioeconomically diverse urban academic institute with a historically underserved patient population. Patients were stratified by the public (Medicare and Medicaid) versus private insurance as a proxy for SDOH. Patient demographics, length of stay (LOS), timing in progression through postoperative recovery milestones, and complications were compared.

Results A total of 162 patients were included, and 57% of patients had public insurance, with this group more likely to be Hispanic (odds ratio [OR] 2.7; p = 0.003) and Spanish-speaking (OR 3.4; p = 0.003). Privately insured patients were more likely to be non-Hispanic Black (OR 2.7; p = 0.006). Patients with public insurance had a higher rate of unplanned return to the operating room within 90 days and a higher incidence of complications, though not statistically significant. They also experienced a significantly longer LOS than privately insured patients (3.6 ± 1.0 vs. 3.0 ± 0.7 days; p < 0.0001). Logistic regression identified an LOS exceeding 3 days as independently associated with public insurance status (OR 3.0; p = 0.03), bilateral procedure (OR 5.6; p = 0.0007), preoperative functional-dependent status (OR 7.0; p = 0.04), and higher body mass index (BMI; OR 1.1; p = 0.03). Patients with public insurance were more likely to encounter delays in achieving recovery milestones.

Conclusion Public insurance status, serving as a proxy for a disadvantage in SDOH, is predictive of extended LOS and postoperative recovery delays following microsurgical breast reconstruction. This underscores the need for future quality improvement efforts to address and mitigate these disparities.
TfOH-Catalyzed Synthesis of Bis(pyrrolo[2,1-a]isoquinolinyl) methanes
Authors: Cui Hai-Lei , Zhou Jing , Sheng Xue , Pan Yu-Yi
Published: November 2024

The synthesis of bis(pyrrolo[2,1-a]isoquinolinyl)methanes was achieved through TfOH-catalyzed sequential Friedel–Crafts alkylation of pyrrolo[2,1-a]isoquinoline and aldehyde. A series of highly functionalized bis(pyrrolo[2,1-a]isoquinolinyl)methane derivatives can be obtained in acceptable to excellent yields (11 examples, up to 96% yield). Interestingly, deformylation was observed when treating pyrrolo[2,1-a]isoquinoline-derived aldehyde and indole under the current reaction conditions. Furthermore, the replacement of aldehyde with isatin resulted in the formation of methylene-bridged dimeric pyrrolo[2,1-a]isoquinoline.
N-Heterocyclic Carbene Switchable Radical- or Benzyne-Meditated Arylation of Thiols Using DMF/KOt-Bu
Authors: Greatrex Ben W. , Puschnig Johannes
Published: November 2024

A mild, metal, and photoredox-free direct arylation of alkyl and aryl thiols with aryl iodides using a DMF/KOt-Bu system has been developed. In the absence of an N-heterocyclic carbene (NHC) additive, the reaction proceeds via a benzyne intermediate and was suitable for the substitution of thiols with phenyl, while the presence of an NHC or phenanthroline derivative improves regioselectivity for the reaction of substituted aryl iodides via a radical pathway. This protocol features inexpensive materials and good substrate scope and could be useful in the arylation of aryl and alkyl thiols.
Comparative Analysis of Comorbidities and Outcomes in Endoscopic versus Open Treatment of Carpal Tunnel Release in Patients with Rheumatoid Arthritis
Authors: Kishan Arman , Kubsad Sanjay , DePalo Jake , Fox Henry Maxwell , Tuffaha Sami H. , Laporte Dawn M. , Nguyen Duc M.
Published: November 2024

Background:  Rheumatoid arthritis (RA) is a known risk factor for carpal tunnel syndrome, possibly because the inflammation causes compression of the median nerve. Endoscopic and open carpal tunnel release (ECTR and OCTR) have been studied extensively in the general population but less so in patients with RA. The purpose of our study was to analyze outcomes and patient-specific comorbidities associated with ECTR and OCTR in patients with RA.

Methods: We conducted a retrospective cohort study using the PearlDiver database to identify patients with RA who underwent either ECTR or OCTR between 2010 and 2014. Demographic data, comorbidities, and complication rates were analyzed. We used univariate and multivariable analysis to assess differences between the treatment methods.

Results:  Comparing 4,234 patients who underwent OCTR to 683 patients who underwent ECTR, we found no significant differences in medical comorbidities such as hypertension, obesity, chronic kidney disease, hypothyroidism, and diabetes mellitus. Patients who underwent ECTR were significantly more likely to require a repeat procedure within 90 days of the initial procedure. However, this difference was not consistent in multivariate analysis controlling for comorbidities.

Conclusion: Our study found that RA and ECTR were identified as independent risk factors for revision release, with ECTR showing a higher likelihood of repeat procedures within 90 days compared with OCTR. Despite similar demographics and comorbidities in the two study cohorts, use of OCTR outpaced ECTR use in the study period. Future research should explore further characterization of repeat procedures in this higher risk patient subset.
Stress and Pregnancy Outcomes: A Review of the Literature
Authors: Miodownik Shayna , Sheiner Eyal
Published: November 2024

The human body has the ability to adapt to changing circumstances, and mobilizes various biological systems in order to do so. When exposed to stressful conditions, the endocrine, nervous, and immune systems come together to aid in maintaining homeostasis; however, during periods of chronic stress, these systems can become maladaptive and lead to long-term detrimental health outcomes. Amongst the lingering effects associated with chronic stress exposure, increasingly, studies are identifying a link to adverse pregnancy and neonatal outcomes. This review explores what has been uncovered in the field to date, and examines the effects of stress on fertility and gestation. Establishing additional factors which put women at risk for adverse pregnancy outcomes can aid in identifying a vulnerable population who could benefit from early stress-reducing interventions.
Early Diagnosis of Subclinical Atherosclerosis in Asymptomatic Type 2 Diabetic Normotensive Menopausal Women: A Global Pulse Wave Velocity Study
Authors: Maiello Maria , Amati Francesca , Caretto Pierpaolo , Ciccone Marco Matteo , Palmiero Pasquale
Published: November 2024

Arterial stiffness serves as a cardiovascular disease marker, aiding in the early identification of high-risk patients. We aimed to evaluate the prevalence of arterial stiffness, measured by global pulse wave velocity (gPWV), among diabetic normotensive menopausal women (DPMW) and its correlation with levels of glycosylated hemoglobin (HbA1c). We recruited 641 consecutive DPMW diagnosed with type 2 diabetes over 5 years. The control group (CG) consisted of 300 normotensive, normoglycemic menopausal women. Normal gPWV was defined as a velocity ≤7.1 m/s. We enrolled 641 DPMW with a mean age of 57 ± 12 years. The CG comprised 300 normotensive, normoglycemic postmenopausal women with a mean age of 56 ± 4 years. Among DPMW, 29 (4.5%) exhibited increased gPWV compared with 4 (1.3%) in the CG (p < 0.01). Of the 225 (35.1%) DPMW with HbA1c > 7.5%, 23 (10.2%) had increased gPWV. In contrast, among the 416 (64.9%) DPMW with HbA1c < 7.5%, only 6 (1.4%) had increased gPWV (p < 0.0001). Electrocardiographic (ECG) abnormalities were detected in 208 (32.4%) DPMW, with 11 (5.3%) of them exhibiting increased gPWV (p = 0.6). There was a higher prevalence of increased gPWV in asymptomatic normotensive DPMW, with a significant association between increased gPWV and elevated HbA1c levels. However, there was no correlation between increased gPWV and abnormal ECG findings, despite ECG being the sole test recommended by current guidelines for all diabetic patients. Early detection of elevated HbA1c levels and increased gPWV may identify asymptomatic DPMW at higher cardiovascular risk, highlighting the inadequacy of a simple ECG in assessing cardiovascular risk in this population.
Symptomatic Severe Stenosis of Cavernous Internal Carotid Artery Stenting: A Case Report with Short Literature Review
Authors: Karki Mohan , Rajpal Girish
Published: November 2024

Intracranial internal carotid artery (ICA) stenosis is rarely reported as compared with extracranial ICA stenosis. Atherosclerosis is one of the major beginnings of stenosis of vasculatures, which may lead to ischemic stroke causing morbidity and mortality. We report the case of a 60 -year-old man presented to us with complaints of multiple episodes of dizziness, mild headache, and transient left arm weakness for 3 months and had history of smoking, hypercholesterolemia (high level of low-density lipoprotein level = 220 mg/dL), diabetes mellitus, and hypertension under medication. No neurological deficits were observed at the time of admission. Patient underwent angioplasty and stenting with drug-eluting balloon-expandable coronary stent. Patient was discharged well at the 3rd day of procedure. No recurrence of stroke and restenosis were noted till 3 months of follow-up period. Stenting following angioplasty for treatment of symptomatic severe cavernous ICA stenosis with everolimus-eluting coronary balloon-expandable stent, Xience Xpedition, is safe and effective.
Love poetry as social practice: On the function of medieval Sicilian love lyric in Arabic and Italian
Authors: Carpentieri Nicola
Published: November 2024

This article problematizes the traditional narrative of Le Origini, according to which the beginnings of Italian literature were based on Provençal examples. I contend that this narrative is incomplete, as it overlooks entirely the rich heritage of Sicilian Arabic poetry that predates the Sicilian romance lyric by only a few decades. Based on a comparative analysis, I aim to demonstrate how the Sicilian romance lyric is also rooted in Sicily’s Islamic past. In support of my argument, I analyze excerpts from three Arabic poems from Islamic and Norman Sicily and then read them alongside Pier della Vigna’s canzone ‘Amor da cui move tuttora e vene’ (Love, from which always come). With my comparison, I call attention to how the poets of the Scuola Siciliana, like their Arabic predecessors at the Kalbid court of Palermo, used verse to craft a code of social competence shaped by the lore and language of the love poem. My comparison opens up a re-examination of Le Origini: can the Sicilian-Arabic poems penned in the tenth, eleventh, and twelfth centuries cast new light on the rhymes of the Scuola Siciliana?
Permanent magnets with embedded phase changing material for electric motor thermal management
Authors: Lamarre Jean-Michel , Ibrahim Maged , Pelletier Roger , Vatandoost Hossein , Bernier Fabrice
Published: November 2024

The magnetic performance of NdFeB permanent magnets rapidly decreases as their operation temperature increases. This limits the power output of electric motors as their internal temperature quickly increases with the power demand. This is particularly problematic for applications where high peak power is required for a short period of time, for example during automobile highway acceleration or during an airplane lift-off. With the advances in additive manufacturing, one can envision to fabricate more complex motor geometries and magnetic structures, without additional costs, allowing for enhanced functionalities such as better thermal management. In this context, this paper investigates the feasibility of using phase changing materials (PCMs) to mitigate the temperature rise in permanent magnets (PMs) fabricated by additive manufacturing. The potential of PCM and its relevance was validated by modeling the thermal response of an electric motor during a representative electric vehicle driving scenario. It was found that segmented magnets with embedded phase changing materials would allow to efficiently control temperature rise. To validate the simulation results, PM test pieces with and without embedded PCMs were fabricated using cold spray additive manufacturing and tested using a custom laser thermal cycling setup.
Investigation of the accuracy of multi-input models using deep learning to estimate the tensile shear strength of adhesive joints
Authors: Shimamoto Kazumasa , Akiyama Haruhisa
Published: November 2024

The correlation between the fracture surface images and residual tensile shear strength of adhesive joints immersed in water was investigated using deep learning. Multi-input models were used to investigate the effects of input parameters on the estimated strength. Specifically, the immersion time and temperature were added as inputs to the fracture surface image to identify the effects of multiple inputs and the conditions that contribute to the improved estimation accuracy. The estimation results showed that the highest accuracy was obtained when both immersion time and immersion temperature were added as input parameters. The variance in the estimated strength tends to be smaller for each additional parameter. To improve the accuracy of estimation using a multi-input model, approximate trends should be estimated for each input parameter alone. Conversely, the use of input parameters for which the trend cannot be estimated may reduce the estimation accuracy.
Improving the polarization switching properties of wurtzite AlN by introducing IV–IV/AlN superlattice and P-doping
Authors: Huang Mingyue , Duan Tianpeng , Jiang Jie , Yang Qiong
Published: November 2024

The large coercive electric field is the main obstacle for the application of wurtzite ferroelectrics in the memory devices. To explore the effective methods to reduce the coercive electric field of wurtzite ferroelectrics, in this work, after screening a series of possible candidates, (MC)1/(AlN)n (M = Ti, Zr) superlattices and anion P-doping are both chosen to regulate the switching energy barrier of wurtzite AlN based on the density functional theory calculations. It is found that the polarization switching energy barriers of wurtzite AlN gradually decrease by increasing the ratio of the MC (M = Ti, Zr) layer. When the ratio of the MC layer is up to 33%, the polarization switching energy barriers of (TiC)1/(AlN)n and (ZrC)1/(AlN)n are decreased by 68% and 55%, respectively, compared with that of pure wurtzite AlN. The anionic P-doping in AlN results in a 48% lower energy barrier. Also, the ferroelectric polarization in the designed superlattices and P-doped AlN is well maintained compared to pure AlN. Thus, the results show that the (MC)1/(AlN)n (M = Ti, Zr) superlattices and anion P-doping approaches are effective in improving the polarization switching properties of wurtzite AlN.
Interatomic Coulombic electron capture beyond the virtual photon approximation
Authors: Šenk Jan , Graves Vincent , Gorfinkiel Jimena D. , Kolorenč Přemysl , Sisourat Nicolas
Published: November 2024

Via the interatomic Coulombic electron capture (ICEC) process, an electron can be captured by an atom or a molecule, while the binding and excess energy is transferred, via a long-range Coulomb interaction, to a neighboring atom or molecule. The transferred energy can be used to ionize or electronically excite the neighboring species. When the two species are asymptotically far apart, an analytical formula for the ICEC cross sections can be derived. The latter can then be estimated using only the energies and the photoionization cross sections of each species. In this work, we develop an analytical model that allows us to predict the ICEC cross sections when the size of the involved species is comparable to the distance between the two entities. Using ab initio R-matrix results for various systems, we show that the new model reduces the error of the asymptotic formula by two orders of magnitude on average while only using parameters that can be taken from the properties of each species.
Gamma-ray back emission from nanowire array irradiated by ultra-intense relativistic laser pulse
Authors: Houng F. T. T. , Hoh S. Y. , Yusuff I. , Tanaka K. A. , Ong J. F.
Published: November 2024

A highly energetic photon is emitted via nonlinear inverse Compton scattering after an electron undergoes scattering with an ultra-intense relativistic laser pulse. In the laser-nanostructured interaction, gamma photons are emitted in different directions due to different electron heating mechanisms. However, the physics that leads to such gamma-photon emission directionality still requires further understanding. This paper shows that ∼53% of the photons emitted from the nanowires fall into the forward-directed cone, with ∼21% of the backward-emitted photons. Using the two-dimensional particle-in-cell simulations, we found that the backward-emitted photons are mainly ascribed to the j × B heating and reflux electrons. The direction of photon emission from the nanowire tip is in the direction of the ponderomotive force. Furthermore, we also demonstrate that the nanowire target attached to the supporting substrate helps to enhance forward photon emission and reduce emission from reflux electrons. Understanding the correlation between the laser heating mechanisms and the directionality of photon emission could provide insights into the generation of collimated gamma rays using nanowire targets for various applications.
Study of unsteady shear flow near stall in a shrouded supercritical carbon dioxide centrifugal compressor
Authors: Cai Ruikai , Yang Mingyang , Yang Bijie , Zhuge Weilin , Martinez-Botas Ricardo F.
Published: November 2024

This study investigates the unsteady shear flow patterns and their relation with the aerodynamic instability of a shrouded supercritical carbon dioxide (SCO2) centrifugal compressor impeller using the dynamic mode decomposition method combined with detached eddy simulation. The results demonstrate that discrete shedding vortex array in the blade tip region is the dominant mode of the SCO2 shrouded centrifugal compressor impeller, with a frequency of 0.5 times the blade passing frequency. In contrast, the main flow structures in the identical impeller using ideal air consist of small-scale shedding vortices near the suction surface and the separated secondary flow. Further analysis of flow field details indicates that the shedding vortex structure inside the shrouded centrifugal impeller originates from the Kelvin–Helmholtz instability generated on the shear interface between the mainstream and the recirculation flow. The greater shear intensity within the SCO2 centrifugal impeller is the reason for the evident occurrence of vortex shedding phenomena in its flow field. Additionally, during the transition from near-stall to stall, vortex pairing phenomena happens at the throat of the centrifugal impeller due to evolutional behaviors of the vortexes. The occurrence of vortex pairing leads to faster blockage of the blade tip region and then the secondary flow spillage over to adjacent passage, ultimately resulting in reverse flow in the blade tip region and extensive blockage at the impeller inlet. The unsteady shear flow evolution clearly demonstrates the processes of stall in SCO2 shrouded impellers.
Extraordinary terahertz transmission and field enhancement via hybrid surface plasmon coupling in rhombic and bow-tie composite aperture metasurface
Authors: Yan Shuzhan , Zhang Xue , Chen Shuyuan , Zeng Jiahao
Published: November 2024

Metasurface that achieves extraordinary terahertz transmission (ETT) and local electric field enhancement (FE) holds significant potential for terahertz studies involving extremely low concentrations of target materials. In this study, we explore a composite aperture metasurface capable of both ETT and local FE. By inserting bow-tie apertures in the “minimum-resonance” zone between four adjacent rhombic lattices, a local FE factor is achieved. Notably, adjusting the configuration of the bow-tie aperture enhances the coupling between surface plasmons, thereby expanding the transmission bandwidth. Through parameter optimization, the metasurface achieves a peak transmission exceeding 95% and a transmittance above 80% in the frequency range of 2.44–3.65 THz, while simultaneously exhibiting a maximum local FE factor of 1005 at 3.45 THz. This approach offers a promising avenue for the design of metasurfaces for spectroscopy and biosensor applications.
Inferring the existence of hydrogen bonds directly from statistical analysis of molecular dynamics trajectories
Authors: Chuiko Valerii , Ayers Paul W.
Published: November 2024

As a demonstration of how fundamental chemical concepts can be gleaned from data using machine learning methods, we demonstrate the automated detection of hydrogen bonds by statistical analysis of molecular dynamics trajectories. In particular, we infer the existence and nature of electrostatically driven noncovalent interactions by examining the relative probability of supramolecular configurations with and without electrostatic interactions. Then, using Laplacian eigenmaps clustering, we identify hydrogen bonding motifs in hydrogen fluoride, water, and methanol. The hydrogen bonding motifs that we identify support traditional geometric criteria.
Simulated investigation of a ku-band relativistic magnetron with modified all-cavity axial extraction at a low magnetic field
Authors: Ding Bin , Ling Junpu , Shi Di-Fu , Pi Mingyao , He Yufang , Zeng Fanbo , Xu Weili , Song Hao
Published: November 2024

Since its invention in 1921 by Hull, magnetrons have undergone rapid development, transitioning from low-power devices to high-power relativistic magnetrons (RMs). However, research on RMs has been predominantly confined to L-X bands until now. To explore the potential of RM in higher frequency bands and align with the trend toward miniaturization of high-power microwave sources, a Ku-band RM has been investigated in this paper. Theoretical analysis dictates the selection of 24 cavities for optimal performance at a low magnetic field. Utilizing a three-dimensional particle-in-cell simulation platform, we demonstrate that the RM can generate a microwave power of 116 MW at a resonant frequency of 13.717 GHz with an electron beam of 126 kV and 2.0 kA, under a magnetic field of 0.22 T, corresponding to a power conversion efficiency of 46%. The integration of a modified all-cavity axial extraction structure in the Ku-band RM allows for a minimized inner radius of the magnetic field system to approximately 25 mm, while maintaining a high-power microwave output.
CdSe quantum dots photoelectric memristors for simulating biological visual system behavior
Authors: He Hui , Zeng Zhicheng , Pei Yifei , Liu Xiangyang , Yan Xiaobing
Published: November 2024

The visual system is the most important in the biological neurosensory system, so simulation of the biological visual system is the key for developing artificial nervous system. This work incorporates a CdSe quantum dot layer into silk fibroin based memristor device, endowing the devices with light-responsive capability. Furthermore, interesting phenomena were observed when the device operated as artificial synapses: excessive voltage stimulation led to a reduction in synaptic weight compared to the responses observed under normal electrical stimulation. This behavior mirrors sensations associated with pain, neuroprotection, and potential injuries to the neural system. At the end, we designed a visual perception system, simulating processes of the biological light intensity perception and the visual degradation response under intense light stimulation. Our research demonstrates the feasibility of constructing an artificial visual nervous system using a hardware system based on memristors.
A novel relaxed modified pipe hydrodynamic model for mixed flow simulation
Authors: Chen Shangzhi , Liu Xin , Rong Guiwen , Zhang Wenlong
Published: November 2024

In this study, we propose a novel modified pipe hydrodynamic model with a partial relaxation approach and develop a corresponding numerical algorithm within the framework of the finite volume method for its computation to enable robust, accurate, and comprehensive pipe modeling. The proposed numerical model provides some key improvements compared to existing numerical schemes for simulating mixed pipe flows: (1) it is capable of preserving both moving- and stationary-water steady states, and (2) it effectively reduces post-bore oscillations while maintaining second-order accuracy in the non-pressurized regime for unsteady pipe flows. Such improvements have been verified against theoretical and experimental data through tests involving both smooth and sharp-gradient steady and unsteady flows across various regimes in straight and locally bent circular pipes, which are fundamental elements of stormwater drainage, sewage networks, and industrial process pipelines. The proposed pipe flow model can be further improved regarding post-pore stability by utilizing specific post-bore oscillation suppression techniques, and it can be integrated into a practical hydraulic modeling tool for pipeline networks in future work.
A magnetohydrodynamic device with concentric ring electrode configuration for mixing intensification—numerical and experimental investigations
Authors: Barman Chitradittya , Bandopadhyay Aditya
Published: November 2024

In this work, we have presented a magnetohydrodynamic (MHD) device with concentric ring electrode configuration, capable of intensifying the process of mixing. The basic principle involves generating MHD flow in the regions enclosed by ring electrode pairs, causing the flow to undergo direction reversal between two adjacent regions. Such a flow pattern results in high degree of stretching of the fluid elements. Through numerical and experimental investigations, we have studied the mixing behavior of a test species in MHD flow and the effect of various operating or control parameters on device performance and conducted comparative analysis of performances of different ring electrode configurations. Experiments have been conducted on a prototype made using three-dimensional (3D) printing, and the experimental observations are found to be in excellent agreement with numerical predictions.
(In,Ga)N-GaN resonant Bragg structures with single and double quantum wells in the unit supercell
Authors: Ivanov A. A. , Chaldyshev V. V. , Zavarin E. E. , Sakharov A. V. , Lundin W. V. , Tsatsulnikov A. F.
Published: November 2024

We study the formation of a superradiant optical mode in the room temperature reflection spectra from resonant Bragg structures (RBSs) composed of single and double (In,Ga)N quantum wells (QWs) in the unit cell. The appearance of the mode manifests itself by a significant increase in the resonant optical reflectivity due to the electromagnetic coupling of quasi-two-dimensional excitons in the QWs. The implementation of the supercells with double (In,Ga)N QWs results in an increase in the oscillator strength of the quasi-2D excitons and corresponding rise of the radiative broadening parameter to the value as high as 0.3 ± 0.02 meV. We also show that the supercells with double QWs are preferable for RBS with large number of periods due to better tolerance to deviations from the exact periodicity.
The effects of dynamic factors inside the bubble on sono-hydrogen yield: A numerical study
Authors: Lv Liang , Song Songsong
Published: November 2024

The formation of H2 by introducing ultrasonic waves to liquid has been widely recognized as a way to provide a clean, efficient, and reliable source of H2, known as Sono-Hydro-Gen. H2 comes from the chemical effects of ultrasonic waves (sonochemistry) caused by the growth and collapse of acoustic cavitation bubbles. In this work, the effects of dynamic parameters (i.e., bubble temperature, the amount of water vapor trapped inside the bubble, and collapse time) in the evolution of cavitation bubbles on H2 production are studied numerically. For an oxygen bubble, computational simulations are performed for the wide range of acoustic amplitudes (1.5–3 atm), ultrasonic frequencies (140–515 kHz), and ambient radii (0.25–20 μm), considering 22 reversible chemical reactions and 10 chemical species inside the bubble. The numerical results show that the amount of water vapor has a significant effect on the bubble collapse temperature. At low excitation amplitudes, the amount of water vapor is not enough to cause the bubble to form a strong collapse. Nevertheless, at high excitation amplitudes, the amount of water vapor is too much to reduce the bubble temperature. There exist optimal values of bubble temperature and amount of water vapor for H2 production. The optimal bubble temperatures are 5267, 4813, 4626, and 3856 K, corresponding to H2 productions of 4.21 × 10−18, 1.29 × 10−18, 2.61 × 10−19, and 8.48 × 10−20 mol, respectively, at ultrasonic frequencies of 140, 213, 355, and 515 kHz. No matter what the excitation parameters are, the optimal water vapor fraction is 0.78 ± 0.04 for H2 production. The obtained results of the present work can provide guidelines for H2 production in acoustic cavitation.
Hemodynamic analysis on the flow characteristics around abdominal aortic hemorrhage site
Authors: Lu Tiandong , Xiong Jing , Hu Wenqing , Xue Song , Xia Zeyang
Published: November 2024

The hemodynamic characteristics of blood flow around the site of abdominal aortic hemorrhage can serve as a valuable indicator for identifying the location of hemorrhage. In this research, we conducted numerical simulations to analyze the flow fields in the patient-specific abdominal aorta with and without hemorrhage. We quantitatively compared differences in flow field patterns, blood loss, and branch vessel perfusion between hemorrhagic and non-hemorrhagic cases. Our numerical results demonstrate that there is a distinct hemodynamic characteristic observed around the hemorrhage site, characterized by continuous abnormal high-velocity (>0.7 m/s) and high-Rortex (>200) zone. Additionally, we evaluated the amount of blood loss and time to moderate shock for different cases of abdominal aortic hemorrhage, while statistically analyzing variations in branch vessel perfusion along the abdominal aorta. These findings provide quantitative estimations for blood loss, branch perfusion, and potential indicators to assess rescue time window as well as evaluate the extent of distal tissue damage and organ injury.
Significance of the smaller scales for hypersonic turbulent boundary layers with focused laser differential interferometry
Authors: Benitez E. K. , Aultman M. , Duan L. , Camillo G. P. , Jewell J. S.
Published: November 2024

While designed to suppress disturbances located away from its beam foci, focused laser differential interferometry (FLDI) is known to have some integration of signals along its optical axis. This is especially true for longer-wavelength signals, although smaller-scale flow structures also have a non-infinitesimal sensitivity length. This study investigates the performance of FLDI in a hypersonic turbulent boundary layer to better understand its behavior. FLDI simulations were conducted using both full-scale direct numerical simulation (DNS) and spatially averaged DNS inputs to directly assess the influence of smaller flow structures on FLDI measurements. The full-scale FLDI results indicate that integration along the optical axis likely results in lower FLDI amplitudes than for true point measurements. Comparison with the spatially averaged FLDI simulations reveals the significance of small-scale structures in FLDI signal roll-off and root mean square amplitudes. Further, the influence of FLDI setup parameters on the response across the frequency spectrum are analyzed. Circular, Gaussian beams with smaller widths are verified to present increased performance relative to elliptical or uniform-intensity beams. Also, measurements using distinct differentiation directions suggest an experimental way to measure turbulence isotropy scales. These results have notable implications for understanding hypersonic turbulent boundary-layer dynamics and interpreting experimental data. Distribution Statement A: Approved for Public Release; Distribution is Unlimited. PA# AFRL-2024-4678; Cleared 08/23/2024.
Analysis of azimuthal electron current driving by rotating magnetic field in field-reversed configuration electric propulsion
Authors: Chen Qiangqiang , Jia Yanhui , Sun Xinfeng , Lv Fangwei , Geng Hai , Rao Bo
Published: November 2024

Field-reversed configuration electric propulsion is an advanced space electromagnetic propulsion technology with significant application prospects but poor thrust performance. To delve into the intrinsic physical mechanisms, a model of the rotating magnetic field penetrating into the plasma and azimuthal electron current driving was developed. The simulation results show that rotating magnetic field strength, frequency, and initial seed plasma density are the key factors that exist as an optimal threshold. Specifically, the rotating magnetic field feed current (i.e., magnetic field strength) was not less than 1000 A, the rotating magnetic field frequency was ∼200–300 kHz, and the plasma density was approximately 1 × 1018 m−3 order of magnitude.
A calibration-informed deep learning model for three-dimensional particle reconstruction of volumetric particle image velocimetry
Authors: Lin Hongtao , Gao Qi
Published: November 2024

Accurately reconstructing three-dimensional particle fields is essential in fluid velocity measurement research. This study addresses the limitations of current three-dimensional (3D) particle reconstruction methods, such as computational efficiency, precision at high particle density, and particle morphology issues, by introducing a calibration-informed deep learning model named the calibrated pixel to voxel convolutional neural network (CPV-CNN) for 3D Particle Reconstruction. This innovative neural network framework employs a unique Gaussian attention mechanism that bridges pixels and voxels, enabling the mapping of pixel features from two-dimensional (2D) particle images to 3D voxel features. This approach eliminates the need for an initial particle field for particle reconstruction, while significantly enhancing reconstruction efficiency. Additionally, the neural network incorporates camera calibration parameters and the physical coordinates of the reconstructed domain, thereby improving the model's generalization capability and flexibility. Numerical experiments demonstrate that CPV-CNN delivers superior results in terms of accuracy, generalization, and robustness in 3D particle reconstruction. The reconstructed particles exhibit favorable morphology, without the elongation issues commonly observed with conventional methods. This achievement illustrates a practical particle reconstruction algorithm based on artificial intelligence (AI) techniques and represents an important step toward developing an end-to-end AI-based particle reconstruction method in the future.
Forced flow reversal in ferrofluidic Couette flow via alternating magnetic field
Authors: Altmeyer Sebastian A.
Published: November 2024

Time-dependent boundary conditions are very common in natural and industrial flows and by far no exception. An example of this is the movement of a magnetic fluid forced due to temporal modulations. In this study, we used numerical methods to examine the dynamics of ferrofluidic wavy vortex flows (WVF2, with dominant azimuthal wavenumber m=2) in the counter-rotating Taylor–Couette system, which was subjected to time-periodic modulation/forcing in a spatially homogeneous magnetic field. In the absence of a magnetic field, all WVF2 states move in the opposite direction to the rotation of the inner cylinder, they are retrograde. However, when strength or frequency of the alternating magnetic field increases, the motion direction of the flow pattern changes. Thus, the alternating field provides a precise and controllable key parameter for triggering the system response and controlling the flow. Aside, we also observed intermittent behavior when one solution became unstable, leading to random transitions in both, the transition time and toward the different final solutions. Our findings suggest that, in ferrofluids, flow pattern reversal can be induced by varying a magnetic field in a controlled manner, which may have applications in the development of modern fluid devices in laboratory experiments. These findings provide a framework to study other types of magnetic flows driven by time-dependent forcing.
Efficient wall-modeling diffused-interface immersed boundary method for solving turbulent flows with high-order finite difference schemes
Authors: Yan Keye , Wu Yue , Zhu Qiming , Cui Yongdong , Khoo Boo Cheong
Published: November 2024

This study presents a novel approach that integrates explicit non-equilibrium wall modeling with the diffused-interface immersed boundary method (IBM) and couples it with high-order compact finite difference method (FDM). This framework efficiently models high Reynolds number turbulent flows over obstacles. The major contributions of this study are as follows: (1) the adaptation of explicit non-equilibrium wall functions within the diffused-interface IBM to create a slip condition, which strikes an effective balance between computational efficiency and accuracy for complex flow scenarios and (2) the incorporation of wall-modeling diffused-interface IBM with high-order compact FDM, leveraging its high computational efficiency during parallel computations and its capability to handle the multiscale nature of turbulent flows. The efficacy of these combined methods is validated through three high Reynolds number test cases: turbulent flow over a circular cylinder, a square cylinder, and a large-span flat roof. The results demonstrate that these methods achieve satisfactory accuracy with coarser grids compared to traditional wall-resolving approaches, underscoring their potential for efficient and practical applications.
Performance sensitivity analysis and aerodynamic optimization of compressor cascades by a turbulence adjoint method
Authors: Li Jiaxing , Luo Jiaqi , Liu Feng , Zheng Yao , Han Zhonghua
Published: November 2024

Sensitivity, which is useful for evaluating the contributions of input variations to output changes, favors designers exploiting the most sensitive design parameters and completing design optimization in aerospace. This study introduces the turbulence adjoint method due to its low computational cost in calculating sensitivities with high accuracy and then solves the adjoint partial differential equations with respect to both the Reynolds-averaged Navier–Stokes and turbulence model equations with the assistance of an automatic differentiation tool. By utilizing the turbulence adjoint method, the sensitivities of aerodynamic performance to the blade profile modifications of two-dimensional and three-dimensional compressor cascades are calculated, allowing for the investigations of the impact of geometric variations on the changes in the flow field. Ultimately, aerodynamic optimization of the compressor cascades is conducted. After optimization, the adiabatic efficiency of the two-dimensional cascade increases by 3.11%, and it increases by 1.15% for the three-dimensional cascade. The variations in flow fields of both the original and optimized cascades are illustrated to discover the origins of performance improvements. The changes in blade profile are almost consistent with those forecasted from sensitivity analysis, demonstrating the potential superiority of the adjoint method for aerodynamic design.
Quorum sensing orchestrates parallel cell death pathways in
Vibrio cholerae
via Type 6 secretion-dependent and -independent mechanisms
Authors: Mashruwala Ameya A. , Bassler Bonnie L.
Published: November 2024

Quorum sensing (QS) is a cell-to-cell communication process that enables bacteria to coordinate group behaviors. In
Vibrio cholerae
colonies, a program of spatial-temporal cell death is among the QS-controlled traits. Cell death occurs in two phases, first along the colony rim, and subsequently, at the colony center. Both cell death phases are driven by the type 6 secretion system (T6SS). Here, we show that HapR, the master QS regulator, does not control
t6ss
gene expression nor T6SS-mediated killing activity. Nonetheless, a Δ
hapR
strain displays no cell death at the colony rim. RNA-Sequencing (RNA-Seq) analyses reveal that HapR activates expression of an operon containing four genes of unknown function,
vca0646-0649.
Epistasis and overexpression studies show that two of the genes,
vca0646
and
vca0647
, are required to drive cell death in both a Δ
hapR
and a Δ
hapR
Δ
t6ss
strain. Thus,
vca0646
-
0649
are regulated by HapR but act independently of the T6SS machinery to cause cell death, suggesting that a second, parallel pathway to cell death exists in
V. cholerae
.
Ca2+ tunneling architecture and function are important for secretion
Authors: Courjaret Raphael J. , Wagner Larry E. , Ammouri Rahaf R. , Yule David I. , Machaca Khaled
Published: November 2024

Ca2+ tunneling requires both store-operated Ca2+ entry (SOCE) and Ca2+ release from the endoplasmic reticulum (ER). Tunneling expands the SOCE microdomain through Ca2+ uptake by SERCA into the ER lumen where it diffuses and is released via IP3 receptors. In this study, using high-resolution imaging, we outline the spatial remodeling of the tunneling machinery (IP3R1; SERCA; PMCA; and Ano1 as an effector) relative to STIM1 in response to store depletion. We show that these modulators redistribute to distinct subdomains laterally at the plasma membrane (PM) and axially within the cortical ER. To functionally define the role of Ca2+ tunneling, we engineered a Ca2+ tunneling attenuator (CaTAr) that blocks tunneling without affecting Ca2+ release or SOCE. CaTAr inhibits Cl− secretion in sweat gland cells and reduces sweating in vivo in mice, showing that Ca2+ tunneling is important physiologically. Collectively our findings argue that Ca2+ tunneling is a fundamental Ca2+ signaling modality.
Stable oxidative posttranslational modifications alter the gating properties of RyR1
Authors: Steinz Maarten M. , Beard Nicole , Shorter Emily , Lanner Johanna T.
Published: November 2024

The ryanodine receptor type 1 (RyR1) is a Ca2+ release channel that regulates skeletal muscle contraction by controlling Ca2+ release from the sarcoplasmic reticulum (SR). Posttranslational modifications (PTMs) of RyR1, such as phosphorylation, S-nitrosylation, and carbonylation are known to increase RyR1 open probability (Po), contributing to SR Ca2+ leak and skeletal muscle dysfunction. PTMs on RyR1 have been linked to muscle dysfunction in diseases like breast cancer, rheumatoid arthritis, Duchenne muscle dystrophy, and aging. While reactive oxygen species (ROS) and oxidative stress induce PTMs, the impact of stable oxidative modifications like 3-nitrotyrosine (3-NT) and malondialdehyde adducts (MDA) on RyR1 gating remains unclear. Mass spectrometry and single-channel recordings were used to study how 3-NT and MDA modify RyR1 and affect Po. Both modifications increased Po in a dose-dependent manner, with mass spectrometry identifying 30 modified residues out of 5035 amino acids per RyR1 monomer. Key modifications were found in domains critical for protein interaction and channel activation, including Y808/3NT in SPRY1, Y1081/3NT and H1254/MDA in SPRY2&3, and Q2107/MDA and Y2128/3NT in JSol, near the binding site of FKBP12. Though these modifications did not directly overlap with FKBP12 binding residues, they promoted FKBP12 dissociation from RyR1. These findings provide detailed insights into how stable oxidative PTMs on RyR1 residues alter channel gating, advancing our understanding of RyR1-mediated Ca2+ release in conditions associated with oxidative stress and muscle weakness.