bluuebunny/crossref_metadata_2025 huggingface dataset:
Detecting and tracking depression through temporal topic modeling of tweets: insights from a 180-day study
Authors: Chandrasekaran Ranganathan , Kotaki Suhas , Nagaraja Abhilash Hosaagrahaara
Published: December 2024

Depression affects over 280 million people globally, yet many cases remain undiagnosed or untreated due to stigma and lack of awareness. Social media platforms like X (formerly Twitter) offer a way to monitor and analyze depression markers. This study analyzes Twitter data 90 days before and 90 days after a self-disclosed clinical diagnosis. We gathered 246,637 tweets from 229 diagnosed users. CorEx topic modeling identified seven themes: causes, physical symptoms, mental symptoms, swear words, treatment, coping/support mechanisms, and lifestyle, and conditional logistic regression assessed the odds of these themes occurring post-diagnosis. A control group of healthy users (284,772 tweets) was used to develop and evaluate machine learning classifiers—support vector machines, naive Bayes, and logistic regression—to distinguish between depressed and non-depressed users. Logistic regression and SVM performed best. These findings show the potential of Twitter data for tracking depression and changes in symptoms, coping mechanisms, and treatment use.
A self-assembled metallo-macrocycle two-qubit spin system
Authors: Douglas Gordon J. , Richards Emma , Sproules Stephen
Published: December 2024

A self-assembled dicopper(ii) metallo-macrocycle is presented as a prototype two-qubit system with a long phase memory time of 5.4 μs.
Recent advances in the design and preparation of graphitic carbon nitride for photocatalysis
Authors: Tong Yuxuan , Xia Jiawei , Hu Yongke , He Yuming , He Guangyu , Chen Haiqun
Published: December 2024

Various synthetic approaches of graphitic carbon nitride (g-C3N4) are reviewed in this article. The unique properties of g-C3N4-based materials prepared by different methods lead to enhanced performance in photocatalytic applications.
Advances in materials and devices for smartlife photovoltaic innovations
Authors: Sun Zhe , Huang Yixiao , Kong Jiahua , Tang Jianguo , Du Zhonglin
Published: December 2024

This review examines materials and device innovations for emerging PV systems, focusing on indoor, semi-transparent, and flexible technologies.
Highly stable and conformal Ti–organic thin films from sustainable precursors via atomic/molecular layer deposition towards green energy applications
Authors: Philip Anish , Lone Umaid , Partanen Olga , Haimi Eero , Karppinen Maarit
Published: December 2024

Stable and conformal Ti–organic thin films from titanium isopropoxide and organic precursors (hydroquinone or benzene dicarboxylic acid) via ALD/MLD technique is reported; conformality is verified with lateral high-aspect-ratio structures.
Sequence-selective pulldown of recognition-encoded melamine oligomers using covalent capture on a solid support
Authors: Escobar Luis , Sun Daniel , Dhiman Mohit , Hunter Christopher A.
Published: December 2024

Covalent capture on polymer beads provides an affinity selection method for the discovery of functional oligomers in mixed sequence libraries of synthetic polymers.
Isolation and characterization of the dimetal decacarbonyl dication [Ru2(CO)10]2+ and the metal-only Lewis-pair [Ag{Ru(CO)5}2]+
Authors: Sellin Malte , Grunenberg Jörg , Krossing Ingo
Published: December 2024

Upon irradiation and carbon monoxide pressure, ruthenium carbonyl reacts with silver(i) and deelectronating reagents to form [Ag{Ru(CO)5}2]+ and [Ru2(CO)10]2+, respectively.
Electrochemical synthesis of phosphorus-containing glycines and peptides via triarylamine-catalyzed dehydrogenative C(sp3)–P coupling
Authors: Ye Zenghui , Qian Yong , Liu Huaqing , Yin Qiwen , Lv Cuili , Zhang Fengzhi
Published: December 2024

An atom-economical and sustainable electrochemically driven triarylamine-catalyzed dehydrogenative phosphorylation coupling was reported.
Thiazole-fused androstenone and ethisterone derivatives: potent β- and γ-actin cytoskeleton inhibitors to treat melanoma tumors
Authors: Adhikary Sanjay , Roy Subrata , Budhathoki Shailesh , Chowdhury Siam , Stillwell Abbey , Basnakian Alexei G. , Tackett Alan , Avaritt Nathan , Milad Mohamed , Alam Mohammad Abrar
Published: December 2024

Several fused-thiazole derivatives have been studied for antimelanoma properties. Lead compounds are effective tumor growth inhibitors in mice, which are potent β- and γ-actin cytoskeleton inhibitors with a probable mechanism of β-PARVIN inhibition.
Probing the interaction of cisplatin with calmodulin and its effect upon binding to myosin light-chain kinase
Authors: Yuan Siming , Wang Shenghu , Cao Kaiming , Wang Yu , Hu Hongze , Tang Liqin , Shen Aizong , Arnesano Fabio , Natile Giovanni , Liu Yangzhong
Published: December 2024

Cisplatin inhibits the interaction between CaM and MLCK, leading to the mobilization of bound Ca2+ ions and disruption of CaM functions. The findings provide mechanistic insights into the neurotoxicity caused by the drug.
A noble-metal-free electrocatalytic system for direct synthesis of α,β-unsaturated carbonyl solids in aqueous solution
Authors: Shao Tianyu , Li Jialu , Wang Chao , Su Ren
Published: December 2024

A two-electrode system for direct synthesis and collection of α,β-unsaturated carbonyls from oxidative coupling of alcohols in aqueous KOH electrolyte.
Regioisomeric manipulation of AIE-active photosensitizers towards multidrug-resistant bacterial eradication
Authors: Zhi Meiliang , Sun Tun , Wang Deliang , Zeng Qiying , Li Ying , Su Xiang , Feng Xing , Tang Ben Zhong
Published: December 2024

We developed an ingenious regioisomeric manipulation approach via a one-step facile strategy to investigate the impact of differently located positive charge on antibacterial performances.
The structure-dynamics feedback mechanism governs the glassy dynamics in epithelial monolayers
Authors: Pandey Satyam , Kolya Soumitra , Devendran Padmashree , Sadhukhan Souvik , Das Tamal , Nandi Saroj Kumar
Published: December 2024

The statics-dynamics feedback mechanism governs the glassy dynamics in confluent epithelial monolayers, which is crucial for wound healing, embryogenesis, cancer progression, etc.
Accelerating the electrochemical performance of solid oxide fuel cells using a Ce(Gd, Bi, Yb)O2−δ diffusion barrier layer acting as an oxygen reservoir at high-current loading conditions
Authors: Kim Hye Young , Lee Sang Won , Lee Seok Hee , Lee Younki , Yu Ji Haeng , Shin Tae Ho
Published: December 2024

Ce(Gd, Bi, Yb)O2−δ with high oxygen storage capacity (OSC) facilitates stable oxygen supply to SOFCs under high current operation, leading to enhanced performance.
A comprehensive review on the mechanism of contact electrification
Authors: Tian Jia , He Yue , Li Fangpei , Peng Wenbo , He Yongning
Published: December 2024

This review summarizes the mechanisms, regulations, influencing factors, and application prospects of contact electrification at different interfaces.
Recent progress towards the development of fluorescent probes for the detection of disease-related enzymes
Authors: Mishra Lopamudra , Mishra Monalisa
Published: December 2024

This review highlights the current advancements in the development of fluorescent probes for the selective detection of disease-relevant enzymes, focusing on their biocompatibility in in vivo models.
Design of a photocatalyst combining graphdiyne–Cu/NiCrO3 with Cu as an interfacial charge-transfer bridge and investigation of its photocatalytic hydrogen evolution performance
Authors: Ding Lu , Jin Zhiliang
Published: December 2024

The electrons move from graphdiyne to Cu due to its higher Fermi level, then react with NiCrO₃ valence band vacancies. NiCrO₃ conduction band electrons reduce H₂, while graphdiyne holes oxidize TEOA.
Boosting room-temperature thermoelectricity in SrTiO3-based superlattices
Authors: Zhu Yi , Wang Wenzhao , Liang Bokai , Liu Wei , Zhou Tao , Meng Biwei , Liu Hao , Gao Wenping , Yang Yulong , Niu Chang , Zheng Changlin , An Zhenhua , Wu Shiwei , Liu Weitao , Zhang Yuqiao , Yuan Chao , Zhu Yinyan , Yin Lifeng , Shen Jian
Published: December 2024

Introducing tensile strain into STO-based superlattices increases the ferroelectric transition temperature, leading to phonon softening at elevated temperatures, which in turn boosts their dimensionless figure of merit (ZT) to 1.2.
Cryo-electron tomography: en route to the molecular anatomy of organisms and tissues
Authors: Schiøtz Oda Helene , Klumpe Sven , Plitzko Juergen M. , Kaiser Christoph J. O.
Published: December 2024

Cryo-electron tomography (cryo-ET) has become a key technique for obtaining structures of macromolecular complexes in their native environment, assessing their local organization and describing the molecular sociology of the cell. While microorganisms and adherent mammalian cells are common targets for tomography studies, appropriate sample preparation and data acquisition strategies for larger cellular assemblies such as tissues, organoids or small model organisms have only recently become sufficiently practical to allow for in-depth structural characterization of such samples in situ. These advances include tailored lift-out approaches using focused ion beam (FIB) milling, and improved data acquisition schemes. Consequently, cryo-ET of FIB lamellae from large volume samples can complement ultrastructural analysis with another level of information: molecular anatomy. This review highlights the recent developments towards molecular anatomy studies using cryo-ET, and briefly outlines what can be expected in the near future.
Advances towards potential cancer therapeutics targeting Hippo signaling
Authors: Zhu Rui , Jiao Zhihan , Yu Fa-Xing
Published: December 2024

Decades of research into the Hippo signaling pathway have greatly advanced our understanding of its roles in organ growth, tissue regeneration, and tumorigenesis. The Hippo pathway is frequently dysregulated in human cancers and is recognized as a prominent cancer signaling pathway. Hence, the Hippo pathway represents an ideal molecular target for cancer therapies. This review will highlight recent advancements in targeting the Hippo pathway for cancer treatment and discuss the potential opportunities for developing new therapeutic modalities.
Probing jet dynamics and collimation in radio galaxies
Authors: Saiz-Pérez Ainara , Fromm Christian M. , Perucho Manel , Porth Oliver , Kadler Matthias , Mizuno Yosuke , Chael Andrew , Mannheim Karl
Published: December 2024

Context. Radio galaxies with visible two-sided jet structures, such as NGC 1052, are sources of particular interest for studying the collimation and shock structure of active galactic nuclei jets. High-resolution very long baseline interferometry observations of such sources can resolve and study the jet collimation profile and probe different physical mechanisms.

Aims. In this paper, we study the physics of double-sided radio sources at parsec scales, and in particular investigate whether propagating shocks can give rise to the observed asymmetry between a jet and a counterjet.

Methods. We carried out special relativistic hydrodynamic simulations and performed radiative transfer calculations of an over-pressured perturbed jet. During the radiative transfer calculations, we incorporated both thermal and nonthermal emission, while taking the finite speed of light into account. To further compare our results to observations, we created more realistic synthetic data including the properties of the observing array as well as the image reconstruction via multifrequency regularized maximum likelihood methods. We finally introduced a semiautomated method of tracking jet components and extracting jet kinematics.

Results. We show that propagating shocks in an inherently symmetric double-sided jet can lead to partially asymmetric jet collimation profiles due to time delay effects and relativistic beaming. These asymmetries may appear in specific epochs, with one jet evolving near conically and the other one parabolically (the width profile evolving with a slope of ≈1 and ≈0.5, respectively). However, these spurious asymmetries are not significant when observing the source evolve for an extended amount of time.

Conclusions. Purely observational effects are not enough to explain a persistent asymmetry in the jet collimation profile of double-sided jet sources and hint at evidence for asymmetrically launched jets.
Exploring spectropolarimetric inversions using neural fields
Authors: Díaz Baso C. J. , Asensio Ramos A. , de la Cruz Rodríguez J. , da Silva Santos J. M. , Rouppe van der Voort L.
Published: December 2024

Context. Full-Stokes polarimetric datasets, originating from slit-spectrograph or narrow-band filtergrams, are routinely acquired nowadays. The data rate is increasing with the advent of bi-dimensional spectropolarimeters and observing techniques that allow long-time sequences of high-quality observations. There is a clear need to go beyond the traditional pixel-by-pixel strategy in spectropolarimetric inversions by exploiting the spatiotemporal coherence of the inferred physical quantities that contain valuable information about the conditions of the solar atmosphere.

Aims. We explore the potential of neural networks as a continuous representation of the physical quantities over time and space (also known as neural fields), for spectropolarimetric inversions.

Methods. We have implemented and tested a neural field to perform one of the simplest forms of spectropolarimetric inversions, the inference of the magnetic field vector under the weak-field approximation (WFA). By using a neural field to describe the magnetic field vector, we regularized the solution in the spatial and temporal domain by assuming that the physical quantities are continuous functions of the coordinates. This technique can be trivially generalized to account for more complex inversion methods.

Results. We have tested the performance of the neural field to describe the magnetic field of a realistic 3D magnetohydrodynamic (MHD) simulation. We have also tested the neural field as a magnetic field inference tool (approach also known as physics-informed neural networks) using the WFA as our radiative transfer model. We investigated the results in synthetic and real observations of the Ca II 8542 Å line. We also explored the impact of other explicit regularizations, such as using the information of an extrapolated magnetic field, or the orientation of the chromospheric fibrils.

Conclusions. Compared to traditional pixel-by-pixel inversions, the neural field approach improves the fidelity of the reconstruction of the magnetic field vector, especially the transverse component. This implicit regularization is a way of increasing the effective signal to noise of the observations. Although it is slower than the pixel-wise WFA estimation, this approach shows a promising potential for depth-stratified inversions, by reducing the number of free parameters and inducing spatiotemporal constraints in the solution.
Large-scale stellar age-velocity spiral pattern in NGC 4030
Authors: Breda Iris , van de Ven Glenn , Thater Sabine , Falcón-Barroso Jesus , Jethwa Prashin , Gadotti Dimitri A. , Onodera Masato , Pessa Ismael , Schaye Joop , Hensler Gerhard , Brinchmann Jarle , Feldmeier-Krause Anja , Krajnović Davor , Ziegler Bodo
Published: December 2024

The processes driving the formation and evolution of late-type galaxies continue to be a debated subject in extragalactic astronomy. Investigating stellar kinematics, especially when combined with age estimates, provides crucial insights into the formation and subsequent development of galactic discs. Post-processing of exceptionally high-quality integral field spectroscopy data of NGC 4030 acquired with the Multi Unit Spectroscopic Explorer (MUSE) has revealed a striking grand design spiral pattern in the velocity dispersion map, that has not been detected in other galaxies. This pattern spatially correlates with HII regions, suggesting that stars currently being born exhibit lower velocity dispersion as compared to surrounding areas where star-formation is less active. We examined the age-velocity relation (AVR) and propose that its configuration might be shaped by a combination of heating mechanisms, seemingly consistent with findings from recent high-resolution cosmological zoom-in simulations. The complex structure of the uncovered AVR of NGC 4030 supports the hypothesis that stellar populations initially inherit the velocity dispersion σ of the progenitor cold molecular gas, which depends on formation time and galactocentric distance, subsequently experiencing kinematic heating due to cumulative gravitational interactions during their lifetime. While advancing our understanding of the AVR, these findings also offer a new framework for investigating disc heating mechanisms and their role in the evolution of galactic discs.
Analysis of Character Education in Gurindam Dua Belas by Raja Ali Haji from the Perspective of TARGHIB WA TARHIB (Exploring the QU’RANI’s Method in Malay Literature)
Authors: Habiba Siti , Hanifah Hanifah , Kurmalasari Tety , Zaitun Zaitun , Musliha Musliha
Published: December 2024

Gurindam dua belas is the ancient poem originated from manuscript of the Malay writer Raja Ali Haji, who has enrichment of life guidance and Malay teaching methods instilled on Islamic law. The purpose of this research is finding the proselytizing methods that are used by Holy Al-Quran. This research utilizes descriptive method by venturing study literature or documentary study. The data collection is through documentation, using the secondary data resources. The findings of this study reveal that Raja Ali Haji in his Gurindam employs Qur’ani methods. There are 33 Targhib and 47 Tarhib methods within the 80 verses of the gurindam which is composed from 12 chapters.
The Critical Thinking Skills In Terms Of Students' Learning Independence In Coastal Areas
Authors: Aprilia Dina , Fernando Adam , Hindrasti Nur Eka Kusuma , Putri Natasya
Published: December 2024

This study aims to analyse critical thinking skills in terms of student learning independence in coastal areas. This type of research is descriptive with a quantitative approach with the population in this study all students of class X SMA Negeri 4 Tanjungpinang. The sample in this study amounted to 30 students. The sampling technique used Stratified Random Sampling. The instrument used is an essay question to measure critical thinking skills on biotechnology material and a closed questionnaire to determine student learning independence. Data analysis technique is inferential statistics. The conclusion of this study is that the critical thinking skills of students with various learning independence (medium, high and very high) are in the medium category.
Attitude profile of prospective UMRAH biology teacher students regarding green technology products
Authors: Fernando Adam , Pratama Yudi , Intasir M. Pemberdi , Siregar Eko Febri Syahputra , Sarkity Dios
Published: December 2024

The development of science and technology today has created various innovations in life, such as green technology. Raja Ali Haji Maritime University (UMRAH), as a higher education institution in Indonesia that produces prospective biology teachers, is responsible for instilling awareness in students about the importance of protecting the environment and implementing sustainability principles through the use of green technology products. However, the extent to which their attitudes towards these green technology products have yet to be widely disclosed. This study aims to determine the attitude profile of prospective biology teacher students at UMRAH towards green technology products. This descriptive study involved 105 new students of the UMRAH Biology Education Study Program in the last two years (2023-2024) as respondents. The instrument used to collect the data was a questionnaire using a Likert scale. Based on the research results that have been obtained, the attitude profile of prospective biology teacher students at UMRAH regarding green technology products is in the good category.
Gesundes-Herz-Gesetz
Authors: Fabisch Gottlobe
Published: December 2024

Der Gesetzentwurf zum Gesundes-Herz-Gesetz wurde in den Medien kontrovers diskutiert, vor allem bezüglich der Maßnahmen zur Früherkennung von Herz-Kreislauf- und Fettstoffwechsel-Erkrankungen. Die Vorschläge zur Änderung der Disease-Management-Programme hingegen fanden kaum öffentliche Beachtung.
Evidenzbasierte Sport- und Bewegungsprogramme für Menschen mit
depressiven Erkrankungen
Authors: Sudeck Gorden , Fiedler David Victor , Rosenstiel Stephanie , Peters Stefan
Published: December 2024

Auf Basis einer erweiterten Erkenntnislage zu Wirkungen von körperlicher
Aktivität auf die psychische Gesundheit haben bewegungsbezogene Empfehlungen
verstärkten Eingang in Leitlinien und Positionspapiere zur Behandlung
depressiver Erkrankungen gefunden. Demgegenüber steht ein unzureichendes Angebot
an evidenzbasierten Sport- und Bewegungsprogrammen für Menschen mit depressiven
Erkrankungen in relevanten Bereichen der Gesundheitsversorgung. Während Sport-
und Bewegungstherapien in der Rehabilitation oder in der stationär-klinischen
Versorgung bereits vielfach verankert sind, ist für den Bereich der ambulanten
Primärversorgung sowohl national als auch international eine
„Implementierungslücke“ zu konstatieren. Der Beitrag trägt vor diesem
Hintergrund zunächst aktuelle Empfehlungen aus Leitlinien und Positionspapieren
zusammen, um darauf aufbauend die Notwendigkeit zur differenzierten Betrachtung
von personalen und kontextuellen Faktoren im Zusammenhang mit psychischen
Gesundheitswirkungen von körperlicher Aktivität zu erörtern. Am Beispiel zweier
aktueller Versorgungsprojekte (ImPuls; STEP.De) wird zum einen ein
Beschreibungsmodell mit dem Schwerpunkt „kontextuelle Einflussfaktoren für
Effekte körperlicher Aktivität auf die psychische Gesundheit“ illustriert. Zum
anderen wird die Gestaltung aktueller Sport- und Bewegungsprogramme im Kontext
der ambulanten Primärversorgung beleuchtet, die zur Schließung von
Versorgungslücken evidenzbasiert beitragen können. Die abschließenden
Implikationen skizzieren weiteren Forschungs- und Entwicklungsbedarf, wobei
insbesondere Fragen der Individualisierung und nachhaltigen Bewegungsförderung
für Menschen mit depressiven Erkrankungen thematisiert werden.
Bestimmung des Ernährungszustandes von mediterranen Landschildkröten
(Testudo spp.) – eine Übersicht
Authors: Frankenberger Julia , Kölle Petra
Published: December 2024

Die Beurteilung des Ernährungszustandes ist bei allen Patienten ein wichtiger
Bestandteil der Allgemeinuntersuchung. Bei Landschildkröten stellt dies aufgrund
ihrer besonderen Anatomie und der Einschränkungen durch den Panzer eine
Herausforderung dar. Trotz ihrer Beliebtheit und des entsprechend hohen
Aufkommens in der tierärztlichen Praxis existiert derzeit kein etablierter
Standard für die Bewertung ihres Ernährungszustandes und der Körperkondition.
Die Auswahl der Untersuchungsmethode ist abhängig von der Ausstattung der
jeweiligen Praxis. Da jede Methode Vor- und Nachteile hat, sollte die Erhebung
des Ernährungszustandes bei Landschildkröten immer auf mehreren Faktoren
basieren. Detailliertes Wissen über die Physiologie von Schildkröten ist bei der
Wahl der richtigen Methode von essenzieller Bedeutung. Der Artikel bietet einen
Überblick über die derzeit bekanntesten Methoden und der Anwendungsmöglichkeiten
in der tierärztlichen Praxis unter Berücksichtigung der physiologischen
Besonderheiten von Landschildkröten.
Analyse: Nachhaltige Beschaffung im Gesundheitswesen: Ein entscheidender Hebel für die Zukunft
Authors: Schenke Anja
Published: December 2024

Nachhaltigkeit spielt eine immer wichtigere Rolle in allen Wirtschaftssektoren – das Gesundheitswesen bildet hierbei keine Ausnahme. Angesichts der enormen Ressourcen, die für den Betrieb von Gesundheitseinrichtungen benötigt werden, ist eine nachhaltige Beschaffung entscheidend, um ökologische und soziale Verantwortung zu übernehmen.
Medizinprodukte: Aufbereitung von Einwegprodukten
Authors: von Eiff Wilfried
Published: December 2024

Welche Konsequenzen ergeben sich aus einem Verbot der CE-Aufbereitung von Einweg-Medizinprodukten für Patientensicherheit, Wirtschaftlichkeit und Nachhaltigkeit? Die CKM-Wegweiser-Studie 2024 gibt Erkenntnisse dazu.
Prospective Cohort Study Investigating Polyunsaturated Fatty Acids and Chronic Lung Disease in Preterm Infants
Authors: Igawa Teryn , Gillespie Tessa C. , Kim Esther S. , Lee Lauren J. , Grogan Tristan , Chu Alison , Calkins Kara L.
Published: December 2024

Objective Chronic lung disease (CLD) is a complication of prematurity. Studies examining the effects of long-chain polyunsaturated fatty acids (LC-PUFAs) on CLD are conflicting. This study investigated LC-PUFAs in the red blood cell membrane (RBCM) in preterm infants.

Study Design This prospective observational study included infants with gestational age <32 weeks or birth weight <2 kg and at least one LC-PUFA measurement in the first month of life. Subjects without CLD (CON group) were compared with those with CLD (CLD group) and then by CLD severity.

Results Seventy infants were included (CON n = 29; CLD n = 41). Twenty-six infants had Grade 1 CLD; 12 had Grade 2 CLD; 3 had Grade 3 CLD. When the CLD group was compared with the CON group, the overall mean (95% confidence interval) RBCM% for linoleic acid (LA) was similar (CLD vs. CON 12.5% [11.7–13.4%] vs. 11.2% [10.2–12.3%], p = 0.06) but the overall mean arachidonic acid (ARA) was lower (17.6% [17.1–18.0%] vs. 18.6% [18.1–19.2%], p < 0.01). During weeks 1 to 4, LA% was similar, while ARA% was lower in weeks 2 and 3 (18.8 ± 2.2% vs. 20.0 ± 1.5%, p = 0.05, 16.8 ± 2.0% vs. 18.3 ± 1.6%, p = 0.01). A similar trend was noted when groups were compared by CLD severity. The CLD group had a higher overall mean α-linolenic acid (ALA) compared with the CON group (0.4% [0.3–0.4%] vs. 0.2% [0.2–0.3%], p < 0.01) but no difference in docosahexaenoic acid (DHA; 3.8% [3.4–4.1%] vs. 3.8% [3.4–4.3%], p = 0.80). During weeks 1 to 4, ALA% was higher during week 1 only (0.4 ± 0.3% vs. 0.2 ± 0.1%, p < 0.01), and DHA% was similar for weeks 1 to 4. Results were similar when groups were compared by CLD severity.

Conclusion In this study, low ARA status was associated with CLD.

Key Points
Stabilization of the high-temperature superconducting phase of Nb3Ge
Authors: Golovashkin A. I. , Pechen’ E. V.
Published: December 2024

A study was made of the stabilizing and destabilizing roles played by various factors in the formation of Nb3Ge films. A model for the stabilization of the high-temperature superconducting phase by oxygen is proposed. Optimization of the conditions of film formation made it possible to attain complete superconductivity at 22.5 °K and Tc = 22.7 °K, with transition to the superconducting state beginning at 23.4 °K.
On singularities in the low-frequency vibration spectrum of a layered crystal
Authors: Glazman L. I. , Kosevich A. M.
Published: December 2024

The high-frequency density of normal mode vibrations of a layered crystal is analyzed in the case when intersection of the constant-frequency “flexural” and “longitudinal” vibration surfaces is possible. Taking account of even small off-diagonal elements of the dynamical force matrix results in hybridization of these vibrations. The location of singularities of the frequency distribution function in the spectrum of new branches of vibrations is discussed.
3D printed respiratory tract enables studies of airborne disease dispersal
Authors: Johnson-Groh Mara
Published: December 2024

The experimental model will help provide a baseline for numerical studies, enable better mask design and improve guidelines for social distancing.
Elastic wave transport in angularly selective valley topological metamaterials plate
Authors: Liu Yan , Wang Lifeng , Gao Yuqiang
Published: December 2024

The valley degree of freedom has attracted increasing attention in elastic wave systems owing to its energy extrema at valleys and great potential in energy transportation. This study investigated the transport of valley edge states by angularly selective excitation in elastic wave metamaterials plate and designed a bifunctional elastic wave device in the bent waveguide containing two different interfaces. The supercell analysis revealed that the valley edge states exhibit symmetrical and anti-symmetrical distributions at two different interfaces. The straight and bent waveguides containing a single interface are designed, and the selective transport of valley edge states is observed due to the symmetrical or anti-symmetrical distributions at the interfaces. The angularly selective excitation of valley edge states by external excitation is demonstrated at the straight and bent interfaces. Based on these transport characteristics of valley edge states and the valley conservation mechanism, a bifunctional elastic wave device composed of a bent waveguide containing both two interfaces is designed. It can realize both the functions of the diode and the backward diode. The designed elastic wave device has the advantages of being a single structure with bifunctions. This study of topological valley transport with angularly selective characteristic may also have practical applications such as energy harvesting and sensing.
Numerical investigation of the fluid-structure interaction of a three-dimensional flexible pitching plate
Authors: Lemartinel N. , Benaouicha M. , Ducoin A.
Published: December 2024

This research numerically investigates the effect of flexibility on the hydrodynamic efficiency of a pitching flat plate. A sinusoidal pitching motion of frequency 0.6, 1.5, and 2 Hz is imposed on the flexible plate immersed in a hydrodynamic flow, at a laminar Reynolds number of 2000. The fluid-structure interaction (FSI) problem is solved with the computational fluid dynamics code FINE/Marine using a modal approach. A parametric study is carried out on the pitching frequency and the flexibility of the plate, to characterize the combined effects of FSI and pitching motion on the hydrodynamic loads. This work contributes to the understanding of hydrodynamic performances of structures operating with high-dynamic motions combined with a significant level of flexibility. First, the influence of the pitching frequency for a rigid plate is analyzed. It is shown that the amplitude of the hydrodynamic coefficients increases with the pitching frequency and their phase is shifted, due to the plate's angular acceleration. The production of lift is found to be a combination of the vortex dynamics and the acceleration effects due to pitch oscillation. The acceleration effects become prevalent over the vortex dynamics at higher pitching frequencies. In the flexible case, it is highlighted that the synchronization of the acceleration effects due to the vibration of the plate and the pitching motion has a crucial influence on the hydrodynamic forces. In the studied range of pitching frequencies, the lift is increased by a factor of 5.5 due to the pitching motion and up to a factor of 2 due to the flexibility. A ratio between the pitching frequency and the natural frequency of the plate is introduced to characterize the effect of flexibility.
The bonded interfacial layer structure of α-Al2O3 (0001)/water at different pH values studied by sum frequency vibrational spectroscopy
Authors: Sun Shumei , Yao Huanzhen , Pan Jiabao , Xian Zhenzhe
Published: December 2024

Oxide/water interfaces are ubiquitous, with alumina/water drawing particular interest due to its environmental and industrial applications. Understanding the interfacial structure at the molecular level is crucial for many physical and chemical processes occurring there. However, the exact structure of interfacial H-bonded network at different pH values remains unclear. Here, sum-frequency vibrational spectroscopy in the OH stretch region was employed to study α-Al2O3 (0001)/water interface at different pH values, while suppressing the contribution of the diffusion layer by adding salts. The experimental results revealed although the variation of pH can charge the surface, it has little impact on the structure of the bonded interfacial layer (BIL). The interaction between alumina and water is mainly governed by weak hydrogen bonds. Furthermore, the templating effect of α-Al2O3 (0001) on the interfacial H-bonded network was observed, with the O–H stretch mode of ∼3430 cm−1 exhibiting anisotropy consistent with the (0001) surface symmetry. These findings indicate that the BIL structure on Al2O3 (0001) is predominantly influenced by the surface atom configuration, and the effect of charge changes induced by pH on the BIL structure is negligible.
Improve neural representations with general exponential activation function for high-speed flows
Authors: Jin Ge , Wang Deyou , Si Pengfei , Liu Jiao , Li Shipeng , Wang Ningfei
Published: December 2024

Characterizing flow fields with neural networks has witnessed a considerable surge in recent years. However, the efficacy of these techniques is typically constrained when applied to high-speed compressible flows, due to the susceptibility of nonphysical oscillations near shock waves. In this work, we focus on a crucial fundamental component of neural networks, the activation functions, to improve the physics-informed neural representations of high-speed compressible flows. We present a novel activation function, namely, the generalized exponential activation function, which has been specifically designed based on the intrinsic characteristics of high-speed compressible flows. Subsequently, the performance of the proposed method is subjected to a comprehensive analysis, encompassing training stability, initialization strategy, and the influence of ancillary components. Finally, a series of representative experiments were conducted to validate the efficacy of the proposed method, including the contact-discontinuity problem, the Sod shock-tube problem, and the converging–diverging nozzle flow problem.
Elastoinertial stability analysis and structure formation in viscoelastic subdiffusive pipe flow
Authors: Bhatt M. , Chauhan T. , Agrawal R. , Kumar M. , Kumar V. , Sircar S.
Published: December 2024

The modal temporal stability analysis of viscoelastic, subdiffusive, pressure driven, axisymmetric pipe flow, representing thick polymer solutions, exhibits the presence of temporally stable regions at high fluid inertia. The stress constitutive equation, previously derived for channel flows [Chauhan et al., Phys. Fluids 35(12), 123121 (2023)] is the fractional variant of the upper convected Maxwell equation. The parameters governing the stability are the Reynolds number, Re=ρU0R0η0, the elasticity number, El=λαη0ρR02, and the ratio of the solvent to the polymer solution viscosity, ν=ηsη0, where R0,U0,ρ,λ,α are the pipe radius, the maximum mean flow velocity, density, the polymer relaxation time, and the fractional order of the time derivative, respectively. The neutral curves indicate, in the limit of small elasticity numbers or in the limit when the viscosity ratio approaches unity, El(1−ν)≪1, that the critical Reynold number, Rec diverges as Rec∼[(1−ν)El]−3α/2, while the critical wavenumber, kc increases as kc∼[(1−ν)El]−α/2. Using a novel fractional variant of the pressure correction method as well as a metric in the Riemannian manifold of symmetric positive definite conformation tensors, the direct numerical simulations quantify the formation of spatiotemporally stable macrostructures (or the non-homogeneous regions of high viscosity) at moderate inertia, thereby corroborating the qualitative features of the experimentally observed flow-instability transition of subdiffusive axisymmetric pipe flows.
Gravity-driven granular drainage from a closed top quasi-two-dimensional rectangular channel
Authors: Maiti Ritwik , Das Gargi , Das Prasanta Kumar
Published: December 2024

The study elucidates the physics of granular drainage from a closed-top quasi-two-dimensional (2D) rectangular channel through extensive visualization, image analysis, and digital particle image velocimetry measurements. Draining initiates at channel inclination slightly above the material repose angle and occurs as avalanche flow, augmented by bubbling at higher channel tilts. However, close to vertical orientation, avalanche flow ceases, resulting in slower emptying. A wide array of drainage patterns is exhibited as function of channel inclination, width, and grain size. Qualitative and quantitative analyses reveal fascinating self-similarity in the different regimes amidst the apparent randomness. Scaling relationships are proposed for drainage time and velocity profile in the moving layer during quasi-steady drainage. Additionally, a depth-averaged continuum model, based on experimental observations, is formulated for the prediction of the moving layer thickness.
Study on the particle dynamic characteristics in a centrifugal pump based on an improved computational fluid dynamics-discrete element model
Authors: Pu Wei , Ji Leilei , Li Wei , Shi Weidong , Tian Fei , Xiao Cui , Yang Qiaoyue , Yang Yang , Agarwal Ramesh
Published: December 2024

To accurately investigate the solid–liquid flow mechanisms within the pump, this study employs an improved Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) approach to examine the solid–liquid interactions in a centrifugal pump. First, the improved CFD-DEM is introduced, focusing on turbulence dissipation near the wall and velocity reconstruction. Then, a comparison is made between the CFD-DEM's performance before and after the enhancements. Finally, an analysis is conducted on how the dynamic characteristics of particles within the pump vary under different solid phase concentration conditions. The study revealed that the particle distribution from the corrected CFD-DEM aligns more closely with the experimental results. At a 2% concentration under the design conditions, the head error was reduced by 0.476%, while the efficiency error decreased by 0.076%. Additionally, as the solid phase concentration increased, there was a corresponding rise in the impact power loss of the particles, dissipative power loss, collision frequency, peak values of particle collisions, and the degree of overlap during these collisions. The comparison revealed that the pressure gradient force has the most significant impact on particle motion. As the pressure gradient force increases, the shear power dissipation of the particles also rises. For solid phase concentrations ranging from 1% to 4%, the average shear power variation during the computation period is between 4.28 × 10−6 W and 5.68 × 10−6 W. As the solid phase concentration increases, the volume fraction of the solid phase distribution on the component wall also gradually rises. These findings provide valuable insights for enhancing the accuracy of research on solid–liquid flow in centrifugal pumps.
On the accuracy of compressibility transformations
Authors: Danis M. Engin , Durbin Paul
Published: December 2024

This study highlights the importance of satisfying the eddy viscosity equivalence below the logarithmic layer, to deriving accurate compressibility transformations. First, we analyze the ability of known transformations to satisfy the eddy viscosity equivalence and show that the accuracy of these transformations is strongly dependent on this ability. Second, in a step-by-step manner, we devise new transformations that satisfy this hypothesis. An approach based on curve fitting of the incompressible Direct Numerical Simulation data for eddy viscosity profiles below the logarithmic layer provides an extremely accurate transformation, which motivates self-contained methods, making use of mixing length formulas in the inner region. It is shown that the accuracy of existing transformations can be significantly improved by applying these ideas, below the logarithmic layer. Motivated by the effectiveness of the formulations derived from eddy viscosity equivalence, we introduce a new integral transformation based on Reynolds number equivalence between compressible and incompressible flows. This approach is based on defining a new compressible velocity scale, which affects the accuracy of transformations. Several choices for the velocity scale are tested, and in each attempt, it is shown that the eddy viscosity equivalence plays a very important role for the accuracy of compressibility transformations.
Flow simulation in curved compound channels: Effect of changing the sinuosity of the main channel and width of floodplain
Authors: Naghavi Mohammad , Mohammadi Mirali , Mahtabi Ghorban
Published: December 2024

In this research, the effect of different sinuosity (s) and width of floodplain on the flow structures in curved compound channels was investigated numerically. Six different sinuosities of main channel (s = 1, 1.026, 1.096, 1.209, 1.381, and 1.641) and three different relative depths (Dr = 0.26, 0.35, and 0.45) have been used. The findings revealed that with the increase in sinuosity from 1 to 1.641 (64% increase), the maximum flow velocity in the apex section (CS1) and the middle crossover section (CS4) decreases by 23% and 62%, respectively. In the relative depth (Dr) of 0.26, 0.35, and 0.45 with the increase in sinuosity from 1 to 1.641 (with the corresponding decrease in width of floodplain), the ratio of main channel discharge to total discharge (Qmc/Q) is reduced by 40%, 45%, and 45%, respectively. Also, with the increase in relative depth (Dr), the main channel discharge is reduced, and the majority of the flows discharge through floodplain, so that with the increase in the relative depth from 0.26 to 0.45, the amount of Qmc/Q in the channel with maximum sinuosity (s = 1.641) and straight channel (s = 1) decreases by 30% and 14%, respectively. With the increase in sinuosity, the changes of v/u and the angle of flow deviation are more noticeable in the middle sections and above the bankfull level, so that in the most critical state, with an increase in the sinuosity from 1 to 1.641, the relative intensity of secondary flow (v/u) increases from 0 to 3.6, and along a meander, the size of the secondary flow cell in each section becomes larger with increasing sinuosity.
Wind loads on square lattice towers with tubular members based on wind tunnel test and numerical simulation
Authors: Liu Muguang , Wu Shikang , Guan Wenxia , Zhang Chunsheng , Xie Zhuangning
Published: December 2024

The square lattice tower with tubular members (SLTTM) is widely used in civil engineering. Wind load is the primary factor affecting the stability of these structures. This paper presents the wind loads of the SLTTM at different Reynolds numbers (Re) through wind tunnel testing and large eddy simulation (LES). A series of wind tunnel tests with four segment models were first conducted to discuss the effects of wind direction, turbulence intensity, and solidity ratio on the aerodynamic force under low and subcritical Reynolds numbers. The LES method was subsequently employed to determine the aerodynamic force coefficient at Re = 191–1.34 × 106 in both the smooth and uniform turbulent wind fields. The results from wind tunnel tests indicate that the mean and fluctuating drag coefficients at low Reynolds numbers are somewhat different from those at subcritical Reynolds numbers. The solidity ratio and wind direction exert a notable influence on the mean drag coefficient, whereas their impact on the fluctuating drag coefficient is relatively minimal. As the turbulence intensity increases, both the mean and fluctuating drag coefficients exhibit a notable rise. The results of the LES at Re = 191–1.34 × 106 show that an increase in turbulence intensity can markedly elevate the fluctuating drag coefficient. However, the effect on the mean drag coefficient is found to depend on the Reynolds number range. The Reynolds number effect on the mean and fluctuating drag coefficients of the SLTTM may be primarily attributed to the members without and with a shielding effect, respectively.
Control parameter layout of compressor airfoils and adaptive optimization method for boundary extension
Authors: Cheng Jinxin , Song Xiancheng , Zhang Yong , Chen Jiang , Xiang Hang
Published: December 2024

Parameterized optimization methods are effective approaches for achieving high aerodynamic performance in compressors. Traditional parameterized optimization methods rely on a designer's preselected control parameter layout (including control frame orientation, point density distribution, control point displacement direction, number of variables, and variable ranges), which are purely based on empirical knowledge without sufficient theoretical basis. This paper selects the free-form deformation (FFD) method and Bayesian algorithm as the parameterization method and optimization algorithm for compressor airfoil optimization and studies the influence of FFD control parameter layouts on aerodynamic optimization performance. Additionally, an adaptive optimization method for control parameters based on FFD is proposed, where the orientation and density of the control framework can be incorporated as variables into the control parameters. During the optimization process, the range of design variables is adaptively expanded. A comparison between FFD optimization results based on B-spline and Bernstein basis functions shows that the former achieves an average performance improvement of 4% relative to the latter. Furthermore, an optimization method with an infinitely expandable boundary based on Bernstein basis FFD is proposed, which improves the performance by 12% compared to general adaptive boundary expansion methods.
Aerodynamic instability of brush seals in gas turbine engines based on a fluid-structure interaction method
Authors: Liu Yuxin , Dong Wenlei , Yue Benzhuang , Kong Xiaozhi , Liu Cunliang
Published: December 2024

By brush seal, we mean a type of mechanical seal that uses a large number of closely packed, thin, and flexible bristles to create an outstanding seal between rotating and stationary components in gas turbine engines. However, at high levels of swirling and pressured environments in engines, bristles of brush seals tend to circumferentially slip, which leads to reduced sealing performance and seal failure. In this paper, the effects of upstream–downstream pressure differences Δp (0.2–0.5 MPa), downstream static pressure (0.1–1.0 MPa), and the coverage of bristles by a front plate (0%–90%) on the mechanical characteristics and deflections of bristles of a brush seal at highly swirling inlet were investigated based on a two-way fluid-structure coupling method. A key criterion for bristle instability, based on a simplified two-dimensional (2D) theoretical analysis, is obtained from the fluid-structure coupling simulations. The results indicate that a fundamental reason for the bristle circumferential slip is the ratio of the normal to the axial aerodynamic forces (Fn/Fax) acting on the first row of bristles. When this ratio exceeds 0.9, the bristles will slip circumferentially. The effects of the pressure differential across the seal, the downstream pressure, inlet swirl velocity, and front plate coverage of the bristles on bristle stability can all be explained through their influences on this force ratio. At relatively low outlet static pressure of 0.1 MPa, upstream bristles slip when the inlet swirl is in the range of 230–300 m/s and the bristle slip instability is more likely to occur at higher pressure difference conditions. However, at high downstream pressures, Fn/Fax declines with the growth of Δp, contributing to the stability tendency. With the constant Δp, the value of Fn/Fax significantly increases as the downstream pressure rises, and the critical swirl velocity required to trigger bristle slip is considerably reduced. Additionally, the front plate shields a part of the bristles away from pressure gradient in axial direction but leads to outward radial flow upstream of the bristle pack, thereby increasing the Fn/Fax. Thus, front plate does not offer protection to bristles under high inlet swirl conditions, on the contrary, it may cause early slip of the bristles.