bluuebunny/crossref_metadata_2025 huggingface dataset:
Azacoumarin-based “turn-on” fluorescent probe for the detection and imaging of hydrogen peroxide in living cells
Authors: Das Samarpita , Chaudhuri Aiswarya , Indurthi Harish K. , Agrawal Ashish K. , Sharma Deepak K.
Published: August 2024

Herein, we demonstrate azacoumarins as potential fluorophores and their application in the synthesis of a “turn-on” fluorescent probe (PYCB) for the detection of H2O2 using a carboxy benzyl boronic pinacol ester as the peroxide recognition unit.
Applications of metal N-heterocyclic carbene complexes in olefin polymerizations
Authors: Feng Ting , Zhang Le , Wu Shang-Xiao , Shi Xiaochao , Han Ying-Feng
Published: August 2024

This review summarizes the progress in recent decades regarding the structure–activity relationships of various well-defined metal-NHC catalysts in the polymerization of olefins, particularly α-olefins, styrene, norbornene, and others.
Emergence of long-range attractive interactions between colloidal particles during curing of dispersion media
Authors: Furuta Yujiro , Kurita Rei
Published: August 2024

Colloids aggregate during curing due to long-range attractions from network heterogeneity. The balance between curing rate and aggregation time can control this process, offering potential improvements in functional polymer manufacturing.
Genetic and epigenetic regulation of cortactin (CTTN) by inflammatory factors and mechanical stress in human lung endothelial cells
Authors: Sun Xiaoguang , Sun Belinda , Sammani Saad , Dudek Steven M , Belvitch Patrick , Camp Sara M. , Zhang Donna , Bime Christian , Garcia Joe G.N.
Published: August 2024

Rationale: Cortactin, an actin-binding cytoskeletal protein, plays a crucial role in maintaining endothelial cell (EC) barrier integrity and regulating vascular permeability. The gene encoding cortactin, CTTN, is implicated in various lung inflammatory disorders. Despite this, the transcriptional regulation of CTTN by inflammatory stimuli and promoter SNPs remains unexplored. Methods: We transfected human lung ECs with a full-length CTTN promoters linked to a luciferase reporter to measure promoter activity. SNP-containing CTTN promoter was created via site-directed mutagenesis. Transfected ECs were exposed to LPS (PAMP), TNF-α (cytokine), cyclic stretch (CS), FG-4592 (HIF-inducer), NRF2 (anti-oxidant modulator), FTY-(S)-phosphate (endothelial barrier enhancer), and 5′-Aza (demethylation inducer). Immunohistochemistry was used to assess cortactin expression in mouse lungs exposed to LPS. Results: LPS, TNF-α, and 18%CS significantly increased CTTN promoter activities in a time-dependent manner (P<0.05). The variant rs34612166 (-212T/C) markedly enhanced LPS- and 18%CS- induced CTTN promoter activities (P<0.05). FG-4592 significantly boosted CTTN promoter activities (P<0.01), which were partially inhibited by HIF1α (KC7F2) and HIF2α (PT2385) inhibitors (P<0.05). NRF2 activator Bixin increased CTTN promoter activities, whereas NRF2 inhibitor Brusatol reduced them (P<0.05). 5′-Aza increased CTTN promoter activities by 2.9-fold (P<0.05). NF-κB response element mutations significantly reduced CTTN promoter activities response to LPS and TNFα. FTY-(S)-phosphate significantly increased CTTN promoter activities in 24 h. In vivo, cortactin levels were significantly elevated in inflammatory mouse lungs exposed to LPS for 18 h. Conclusion: CTTN transcriptional is significantly influenced by inflammatory factors and promoter variants. Cortactin, essential in mitigating inflammatory edema, presents a promising therapeutic target to alleviate severe inflammatory disorders.
EWOCS-II: X-ray properties of the Wolf–Rayet stars in the young Galactic super star cluster Westerlund 1
Authors: Anastasopoulou K. , Guarcello M. G. , Flaccomio E. , Sciortino S. , Benatti S. , De Becker M. , Wright N. J. , Drake J. J. , Albacete-Colombo J. F. , Andersen M. , Argiroffi C. , Bayo A. , Castellanos R. , Gennaro M. , Grebel E. K. , Miceli M. , Najarro F. , Negueruela I. , Prisinzano L. , Ritchie B. , Robberto M. , Sabbi E. , Zeidler P.
Published: August 2024

Context. Wolf–Rayet (WR) stars are massive evolved stars that exhibit particularly fast and dense stellar winds. Although they constitute a very short phase near the end of a massive star’s life, they play a crucial role in the evolution of massive stars and have a substantial impact on their surrounding environment.

Aims. We present the most comprehensive and deepest X-ray study to date of the properties of the richest Wolf–Rayet population observed in a single stellar cluster, Westerlund 1 (Wd1). By examining the X-ray signatures of WR stars, we aim to shed light on the hottest plasma in their stellar winds and gain insights into whether they exist as single stars or within binary systems.

Methods. This work is based on 36 Chandra observations obtained from the “Extended Westerlund 1 and 2 Open Clusters Survey” (EWOCS) project, plus 8 archival Chandra observations. The overall exposure depth Ms) and baseline of the EWOCS observations extending over more than one year enable us to perform a detailed photometric, colour, and spectral analysis, as well as to search for short- and long-term periodicity.

Results. In X-rays, we detect 20 out of the 24 known Wolf–Rayet stars in Wd1 down to an observed luminosity of ~7 × 1029 erg s−1 (assuming a distance of 4.23 kpc to Wd1), with 8 WR stars being detected in X-rays for the first time. Nine stars show clear evidence of variability over the year-long baseline, with clear signs of periodicity. The X-ray colours and spectral analysis reveal that the vast majority of the WR stars are hard X-ray sources (kT≥2.0 keV). The Fe XXV emission line at ~6.7 keV, which commonly originates from the wind–wind collision zone in binary systems, is detected for the first time in the spectra of 17 WR stars in Wd1. In addition the ~6.4 keV fluorescent line is observed in the spectra of three stars, which are among the very few massive stars exhibiting this line, indicating that dense cold material coexists with the hot gas in these systems. Overall, our X-ray results alone suggest a very high binary fraction (≥80%) for the WR star population in Wd1. When combining our results with properties of the WR population from other wavelengths, we estimate a binary fraction of ≥92%, which could even reach unity. This suggests that either all the most massive stars are found in binary systems within Wd1, or that binarity is essential for the formation of such a rich population of WR stars.
Weighing Milky Way and Andromeda in an expanding ΛCDM Universe
Authors: Benisty David
Published: August 2024

The dynamics of the Local Group (LG), especially the contribution of the Milky Way (MW) and Andromeda (M 31) galaxies, is sensitive to the presence of dark energy. This work analyzes the evolution of the LG by considering it as a two-body problem in a homogeneous and isotropic expanding spacetime in a full Λcold dark matter (ΛCDM) background. Using the timing argument (TA), which links LG dynamics to LG mass, we find that the full ΛCDM background predicts a ∼10% lower mass for the LG; whereas Λ alone predicts a ∼10% higher mass. The TA mass is modified by (i) simulations and (ii) the effect of the Large Magellanic Cloud (LMC) to alleviate the poorly constrained internal mass distributions of M 31 and the MW, their time evolution, and the unknown distribution of dark matter between them. First, using IllustrisTNG simulations, we accounted for the effects of two extended halos and their environment (rather than point particles) and predicted their mass (3.89 ± 0.62)×1012 M⊙. Second, the LMC effectively changes the separation and velocities of M 31 towards the MW and reduces the predicted mass to (2.33 ± 0.72)×1012 M⊙. Despite the uncertainties around dark matter between these galaxies, the overall estimated mass is compatible with the mere sum of the MW and M 31 masses. The total mass of the TA is compatible with other estimates, such as the Hubble flow and the Virial Theorem with other dwarf galaxies. The combined result shows, for the first time, that a lower mass estimate can be obtained from the TA, with a consistent embedding and other systematic effects, and without an additional dark matter halo around the galaxies.
Understanding the star formation efficiency in dense gas: Initial results from the CAFFEINE survey with ArTéMiS
Authors: Mattern M. , André Ph. , Zavagno A. , Russeil D. , Roussel H. , Peretto N. , Schuller F. , Shimajiri Y. , Di Francesco J. , Arzoumanian D. , Revéret V. , De Breuck C.
Published: August 2024

Context. Despite recent progress, the question of what regulates the star formation efficiency (SFE) in galaxies remains one of the most debated problems in astrophysics. According to the dominant picture, star formation (SF) is regulated by turbulence and feedback, and the SFE is ~1–2% or less per local free-fall time on all scales from Galactic clouds to high-redshift galaxies. In an alternate scenario, the star formation rate (SFR) in galactic disks is linearly proportional to the mass of dense gas above some critical density threshold ~104 cm–3.

Aims. We aim to discriminate between these two pictures thanks to high-resolution submillimeter and mid-infrared imaging observations, which trace both dense gas and young stellar objects (YSOs) for a comprehensive sample of 49 nearby massive SF complexes out to a distance of d ~ 3 kpc in the Galactic disk.

Methods. We used data from CAFFEINE, a complete 350/450 µm survey with APEX/ArTéMiS of the densest portions of all southern molecular clouds at d ≲ 3 kpc, in combination with Herschel data to produce column density maps at a factor of ~4 higher resolution (8") than standard Herschel column density maps (36″). Our maps are free of any saturation effect around luminous high-mass pro-tostellar objects and resolve the structure of dense gas and the typical ~0.1 pc width of molecular filaments out to 3 kpc, which is the most important asset of the present study and is impossible to achieve with Herschel data alone. Coupled with SFR estimates derived from Spitzer mid-infrared observations of the YSO content of the same clouds, this allowed us to study the dependence of the SFE on density in the CAFFEINE clouds. We also combine our findings with existing SF efficiency measurements in nearby clouds to extend our analysis down to lower column densities.

Results. Our results suggest that the SFE does not increase with density above the critical threshold and support a scenario in which the SFE in dense gas is approximately constant (independent of free-fall time). However, the SF efficiency measurements traced by Class I YSOs in nearby clouds are more inconclusive, since they are consistent with both the presence of a density threshold and a dependence on density above the threshold. Overall, we suggest that the SF efficiency in dense gas is primarily governed by the physics of filament fragmentation into protostellar cores.
Limitations and rotation of the two-armed phase spiral in the Milky Way stellar disc
Authors: Alinder S. , McMillan P. J. , Bensby T.
Published: August 2024

Context. The Milky Way’s history of recent disturbances is vividly demonstrated by a structure in the vertical phase-space distribution known as the Gaia phase spiral. A one-armed phase spiral has been seen widely across the Milky Way disc, while a two-armed one has only been observed in the solar neighbourhood.

Aims. This study aims to determine the properties of the two-armed phase spiral and to put it in a Galactic context, with the ultimate goal of understanding the structure and history of the Milky Way disc.

Methods. The Gaia DR3 data were used to trace and characterise the two-armed phase spiral. Special focus was put on the phase spiral’s spatial distribution, rotational behaviour, and chemical characteristics. To quantify the properties of the phase spiral, we used a model that fits a spiral pattern to the phase space distribution of the stars.

Results. We found that the two-armed phase spiral is detectable only within a narrow range of galactocentric distances and angular momenta in the solar neighbourhood, R = 8 ± 0.5 kpc, LZ = 1450 ± 50 kpc km s−1. Outside this region, the phase spiral is one-armed. The two-armed phase spiral rotates with the phase angle, in a similar way to the one-armed phase spiral, and changes axis ratio with phase angle. Additionally, stars within the phase-space overdensity caused by the two-armed phase spiral pattern have slightly higher mean metallicity than stars in the underdense regions of the pattern at equivalent galactocentric distances, angular momenta, and vertical orbit extents.

Conclusions. The two-armed phase spiral rotates with phase angle and its effect can be seen in metallicity, in a similar way to the one-armed phase spiral. However, the limited range over which it can be found, and its variation in shape are quite different from the one-armed version, suggesting it is a much more localised phenomenon in the Galactic disc.
CMFGEN grids of atmosphere models for massive stars
Authors: Marcolino W. , Bouret J.-C. , Martins F. , Hillier D. J.
Published: August 2024

Context. Large spectroscopic surveys of individual massive stars, such as ULLYSES and XShootU, provide observational data for hundreds of massive stars. Their analysis requires large numbers of synthetic spectra so that stellar parameters can be determined. In addition, libraries of massive stars’ spectra are needed to produce population synthesis models able to reproduce the observed spectra of unresolved young stellar populations, such as those revealed by the James Webb Space Telescope (JWST) in the early Universe.

Aims. Our main goal is to provide an extensive library of synthetic spectra and spectral energy distributions of OB stars at metallicities of the Magellanic Clouds. This library will offer a wealth of spectrophotometric information, making it readily applicable to a variety of astrophysical problems.

Methods. We used the CMFGEN code to calculate 606 NLTE, line-blanketed, expanding atmosphere models using a comprehensive set of atomic data. An overall metallicity of 1/2 Z⊙ and 1/5 Z⊙ was adopted for the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC), respectively. We produced high-resolution spectra from 30 Å to 3 µm for stars on the Main Sequence and slightly beyond.

Results. We provide spectral energy distributions, normalized synthetic spectra, ionizing fluxes, and photometry in various bands: Johnson UBV, Cousins RI, Bessel JHK, selected wide JWST filters, Gaia, and LSST ugrizy filters. For each of these filters, we compute bolometric corrections for all synthetic spectra and calibrations as a function of effective temperature.

Conclusions. All of our synthetic spectra are publicly available through the POLLUX database, aiming to expedite multiwavelength analyses of massive stars in low metallicity environments.
Une dialectique récurrente : des dangers aux risques des expositions aux rayonnements ionisants
Authors: Pasquier J.L. , Bourguignon M. , Bertho J.M.
Published: August 2024

Les notions de danger et de risque sont très souvent confondues. Bien qu’étant proches, elles recouvrent des réalités différentes, que ce soit dans le domaine des risques naturels et technologiques ou dans d’autres domaines. Ceci est vrai également dans le domaine de la radioprotection. De plus ces deux notions évoluent dans le temps avec les évolutions de la société et la perception sociale du risque. Ces évolutions entraînent des conséquences sur le système de radioprotection qui devront être prises en compte dans les études de risque et les réflexions en cours sur l’évolution des recommandations générales de la CIPR.
Francophone literature in the digital age: Language and style
Authors: Petrenko Tatyana , Levina Natalya , Airapetov Gurgen , Keleynikova Alla , Kotliarevskaia Innessa
Published: August 2024

The article is centered on the digital methods of representing a literary text. The aim of this article is to pinpoint the stylistic characteristics of new forms of narrative organization in the French-speaking sector of the Internet. The general scientific methodology of the research was formed by works on narratology (R. Barthes, M. Bakhtin, Y. Lotman) and text digitalization (S. Bouchardon), studies in the field of visual semiotics and polycode (U. Eco, J.-M. Klinkenberg, V.E. Chernyavskaya, etc.), as well as in the field of punctuation and graphic organization of visual prose (T.F. Semyan). This article analyses the stylistic features of a new model of writing by Francophone authors - online literary blogs and novels. This research contributes to the academic field of literature and digital technologies, broadening our comprehension of the stylistic aspects of new forms of narrative. The originality of the work lies in the fact that it examines the impact of the Internet on culture exclusively through the prism of literature and analyses new forms of text organization in the context of digital space. It was found that online writing not only creates new modes of expression, but also brings about changes in existing genres. Contemporary digital literature exists in the form of interactive and generative texts, visual poetry, online literary blogs and novels. The analysis showed that literary blogging promotes hybridization by intertwining genres inherited from print and digital formats. The analyzed online blogs and novels are characterized by fragmentation, non-linearity, hybridity, incompleteness, lack of a unified plot and visualization.
M.-S. Gadaev. Moral and ethical side of creativity
Authors: Khazhbikarova M.I. , Yakhyaeva Z.I. , Abdulazimova T.K.
Published: August 2024

This article discusses issues of the history of Chechen literature. Using the example of the creativity of M.S. Gadaev conducted a small analysis of poetic works. An analysis of morality and philosophy in the works of this author is carried out. Issues of the author’s creative and life path are also covered, and small excerpts from the author’s works are also given.
Moral	and	humanistic	ideas	in	the	work	of modern Chechen poets
Authors: Muskhanova I.V. , Timaeva Kh.N. , Alkhastova Z.M.
Published: August 2024

This article examines and analyzes questions about moral and philosophical reflections in the works of Chechen poets A. Yusupov, L. Abdulaev, B. Shamsudinov. An analysis of several works by these poets was carried out. The work of all three poets occupies a large place in modern Chechen literature; each of the poets conveys the flavor of the national mentality in their own way. We can firmly say that they themselves are eyewitnesses of some of the events that they describe in their works. All of them were eyewitnesses of the events that took place in the history of our people, and it is not difficult for them to convey through their heroes the moral and psychological state of the people... The text says how poets, together with their people, experience all the difficulties that concern the Chechen people and its history. The work also highlights some autobiographical issues in the development of poets.
Psychological motives in the works of modern Chechen writers
Authors: Muskhanova I.V. , Selmurzaeva Kh.R. , Yasaeva M.L.
Published: August 2024

This scientific work examines issues of the history of Chechen literature. Using the example of the works of M. Akhmadov, M. Gadaev and B. Shasudinov, an analysis of the works was carried out. Issues of the creative and life path of the authors are covered. The article analyzes short excerpts from the authors’ works. The issues of Chechen literature of the last two decades are also considered, and about those representatives who appear as if at the confessional altar, exploring the causes of the recent military crisis, the war itself and its dire consequences... We see this in the works of famous prose writers: M. Akhmadov, M. Beksultanov- TO. Ibragimova. E. Minkailov, and young authors: I. Gunaeva, I. Zakriev. E. Litaeva, S. Musaeva, M. Khasaeva, A. Shataeva, B. Shamsudinov.
Representation of the category of imperativeness in Russian and English languages: Comparative aspect (based on the material of military command and orders)
Authors: Bazhutkina Natalia , Agapitova Alexandra , Kapitonova Nina
Published: August 2024

The article is devoted to ways of expressing the category of imperativeness in English and Russian using the material of military commands and orders. The article discusses the concepts of category, mood and imperative mood, presents ways to modify the meaning of the imperative mood, studies the structure of combat commands in English and Russian, as well as ways to convey the category of imperativeness in military orders when translated them from English into Russian. A comparative analysis of the transmission of the category of imperativeness in English and Russian was carried out using the material of military commands and orders.
Comparative analysis of the Perfect in German, English and Chechen languages
Authors: Arsakhanova Malyutkhan , Gatsaeva Aksana
Published: August 2024

Recently, a lot of research has been devoted to the typological analysis of languages. The article examines the functional features of the Perfect in German, English and Chechen languages. A comparative analysis shows that these three languages have many similarities and differences in the formation and use of tense forms. The Perfect forms of the three languages differ in grammatical tenses in exactly the same way as the non-perfect forms. In addition to effective action, Perfect tenses are used in colloquial speech and denote action in the Past. The Perfect (Present Perfect tense) in German is more flexible, whereas in English and Chechen it is necessary in some situations to be expressed in other tenses. These differences and the reasons behind them attract the attention of many researchers to a comparative analysis of the category of time, in particular the Perfect.
Formation of national identity as the basis of intercultural communication
Authors: Magdanovna Ekhaeva Raisa , Arskieva Zalia Abasovna , Vershitsky Andrey Vyacheslavovich
Published: August 2024

The work talks about the development of national identity as a factor that binds the culture of interpersonal relations and promotes the unity of all citizens, regardless of their ethnic origin, political or religious beliefs. National identity is an integrative quality. a personality that combines internal freedom and respect for government , love for the Motherland and the desire for peace, self-esteem and perseverance, as well as the ability to demonstrate a culture of interpersonal relationships. The article reflects a study of the development of the formation of national self-awareness of primary school students and includes knowledge of their cultural heritage and thus entails an understanding of their personality and how it positions itself in society. National identity is a factor that binds a nation as a single spiritual and sociocultural community.
Intercultural Educational Policy: Strategies and Implementations in a Globalized World
Authors: Yarychev Nasrudi
Published: August 2024

In the era of globalization, educational policies promoting intercultural interaction are pivotal for fostering understanding and collaboration across diverse cultural contexts. This article explores strategies and practical implementations of intercultural educational policies aimed at addressing challenges and leveraging opportunities in a globalized world. Theoretical foundations of intercultural education are discussed, emphasizing its relevance in preparing individuals to navigate complex multicultural environments. Additionally, the article examines current strategies and practical applications of intercultural educational policies, including curriculum development, teacher training programs, cultural exchange initiatives, and institutional collaborations. It analyzes how these policies integrate cultural diversity into educational practices, promoting inclusivity and equity. Moreover, challenges encountered in implementing intercultural educational policies such as resistance to change, cultural biases, and resource limitations are explored. Effective approaches to overcoming these challenges, including stakeholder engagement, policy adaptation to local contexts, and ongoing evaluation and improvement, are discussed.
The influence of psychological separation on the development of value-sense sphere of adolescents
Authors: Bulueva Shumisat , Makarov Ivan , Byrylova Elena
Published: August 2024

The article examines in detail the concept of separation from the point of view of various psychological theories. We can conclude that separation is a complex and complex process that occurs individually, depending on the personal characteristics of family members, the characteristics of the family system, the age and gender of the child, and is based on long-term deep trusting relationships. Let us dwell on the study of the types and types of separation. Separation is a natural process that is necessary for the development of a healthy personality. However, it is important to remember that this does not mean cutting yourself off from your parents for life. Some connection with parents may remain important to a person throughout his life. It is important to find a balance between independence and connection with family. In general, psychological separation is a necessary stage in the development of a teenager, but its influence on the value-semantic sphere can be ambiguous. It is important that parents help their children through this process and try to maintain open and understanding communication with them. The separation process begins in adolescence and can continue throughout adulthood. Its main goal is to form a personality capable of independent decision-making and responsibility for their actions.
Intercultural	communication	and	modern challenges of global education
Authors: Alexandrova Natalia , Rima Simbuletova , Fariza Kulaeva
Published: August 2024

Today, development is recognized as more intricate than in the past. Scholars and practitioners observe a shift in the development landscape since the turn of the millennium, emphasizing culture’s increasing role in social life. In postmodern theory, culture asserts a predominant position among other societal spheres. A balanced view positions culture as a vital component of everyday experience, marking a transition from a scarcity-driven society where economic necessity confines human behavior to a world where individual choice is expanded by the growing influence of the human factor over external conditions. This perspective does not narrowly define culture solely as high art or achievement of cultural standards seen in official discourse, but rather embraces its broad spectrum of manifestations across public life, representing the future direction of cultural policy.
New shrimp-shaped structure unlocks research avenues in nonlinear dynamics
Authors: Lim Alane
Published: August 2024

Researchers discover quasi-periodic shrimp and uncover how it differs from periodic shrimp.
Expanding density-correlation machine learning representations for anisotropic coarse-grained particles
Authors: Lin Arthur , Huguenin-Dumittan Kevin K. , Cho Yong-Cheol , Nigam Jigyasa , Cersonsky Rose K.
Published: August 2024

Physics-based, atom-centered machine learning (ML) representations have been instrumental to the effective integration of ML within the atomistic simulation community. Many of these representations build off the idea of atoms as having spherical, or isotropic, interactions. In many communities, there is often a need to represent groups of atoms, either to increase the computational efficiency of simulation via coarse-graining or to understand molecular influences on system behavior. In such cases, atom-centered representations will have limited utility, as groups of atoms may not be well-approximated as spheres. In this work, we extend the popular Smooth Overlap of Atomic Positions (SOAP) ML representation for systems consisting of non-spherical anisotropic particles or clusters of atoms. We show the power of this anisotropic extension of SOAP, which we deem AniSOAP, in accurately characterizing liquid crystal systems and predicting the energetics of Gay–Berne ellipsoids and coarse-grained benzene crystals. With our study of these prototypical anisotropic systems, we derive fundamental insights on how molecular shape influences mesoscale behavior and explain how to reincorporate important atom–atom interactions typically not captured by coarse-grained models. Moving forward, we propose AniSOAP as a flexible, unified framework for coarse-graining in complex, multiscale simulation.
A high-throughput flowless microfluidic single and multi-solute concentration gradient generator: Design and parametric study
Authors: Reddy Mallikarjun P. V. N. , Bachal Ketaki , Gandhi Prasanna , Majumder Abhijit
Published: August 2024

Microfluidic concentration gradient generators (μ-CGGs) are critical in various biochemical assays, including cell migration, drug screening, and antimicrobial susceptibility testing. However, current μ-CGGs rely on integration with flow systems, limiting their scalability and widespread adoption owing to limited infrastructure and technical expertise. Hence, there is a need for flowless diffusional gradient generators capable of standalone operation, thereby improving throughput and usability. In this study, we model such a diffusional μ-CGG as an infinite source–sink system to capture two characteristic timescales: (i) gradient generation dictated by the diffusion timescale and (ii) stability determined by the rate of change in reservoir concentrations. Through finite-element simulations, we explored the influence of various geometric parameters such as the channel length, cross-sectional area, node and reservoir volumes, and the solute diffusivity on these timescales, along with experimental confirmation using fluorescent tracer diffusion. Our results show that while the gradient stability strongly depends on the reservoir volumes, diffusion length, and solute diffusion coefficient, they are independent of the node shape or the shape of the channel cross section. However, gradient profiles were found to be the strong functions of the diffusion length, solute diffusivity, and the geometric pattern of the microfluidic grid. Additionally, we showcased the versatility of the design by generating discrete gradient profiles and combinatorial gradients of two and three solutes, thus improving throughput in a wide range of on-chip biological assays. These findings underscore the potential of our microfluidic device as an easy-to-use, inexpensive, efficient, and high-throughput platform for various on-chip biological assays.
High-voltage pulse generator for time-of-flight mass spectrometry in electrospray thrusters
Authors: Villegas-Prados D. , Blázquez-Plaza F. J.
Published: August 2024

Electrospray thrusters exhibit diverse operational modes based on the nature of ejected particles. Time-of-flight mass spectrometry is frequently employed to analyze the composition of the plume. This study introduces a novel converter-based bipolar high-voltage pulse generator aimed at producing synchronized bipolar high-voltage pulses with controllable voltage levels and frequencies, specifically tailored for the study of electrospray thrusters. The proposed topology generates bipolar high-voltage rails from a low-voltage power source through the forward–flyback with Cockcroft–Walton voltage multiplier topology. Subsequently, fast high-voltage MOSFETs are employed to generate high-voltage pulses. This paper outlines the operational principles and design methodologies of the pulse generator. Experimental verification corroborates its operational principles and functionalities, revealing that the pulse rise and fall times consistently remain below 30 ns, while the voltage can be tuned within the range of 300–1000 V. An electrospray thruster was employed to conduct a thorough and practical validation of the high-voltage pulse generator. This included generating time-of-flight curves and mass spectra of the plume, resulting in precise differentiation of all particles present.
The effect of CO content on CH4/CO/H2 rotating detonation wave propagation characteristics
Authors: Liu Zhuyong , Yang Jianlu , Bai Qiaodong , Han Jiaxiang , Wang Maojie , Li Hang , Zheng Quan , Xu Han , Weng Chunsheng
Published: August 2024

Rotating detonation experiments were conducted using CH4/CO/H2 (methane/carbon monoxide/hydrogen) mixtures with varying CO contents, the modes of rotating detonation wave (RDW) propagation in the mixtures were analyzed, and the impact of CO content on the propagation characteristics of the RDW in the gas mixture was compared. Three propagation modes of RDW were observed: sawtooth wave mode, mixed mode, and single wave mode. An increase in the CO content resulted in an upward shift in the range of working equivalence ratios for different gas mixtures. Additionally, the propagation modes of the same gas mixture change with increased fuel flow rate. When the equivalence ratio is below 1.13, it is observed that the gas mixture with the lowest CO content exhibits the highest RDW velocity and the shortest time required to establish RDW. This was attributed to the higher content of oxygen-containing functional groups, such as OH (hydroxyl), HO2 (peroxyhydroxyl), and O (oxygen atom), which were present under lean combustion conditions, along with the highest mass content of H2 in the gas mixture with the lowest CO content. Conversely, for equivalence ratios above 1.13, it is observed that the gas mixture with the highest CO content exhibits the highest propagation velocity and the shortest time required to establish RDW. This was attributed to the lowest mass content of CH4 and H2 in the gas mixture with the highest CO content at the same equivalence ratio, along with the inhibitory effect of elevated CO content on CH4 consumption under fuel-rich combustion conditions. The increase in the CO content resulted in maximum propagation velocities of the detonation wave being achieved for the three gas mixtures at equivalence ratios of 0.91, 1.09, and 1.19, with corresponding velocities of 1136.7, 1108.7, and 1113.2 m/s, and the shortest times required to establish RDW were measured at 1.5, 1.1, and 0.8 ms for the respective mixtures.
Dynamic behaviors of far and near memristive electromagnetic induction in spoon neural network
Authors: Lai Qiang , Xu Yudi
Published: August 2024

In this paper, a special spoon neural network is proposed, which is composed of four neurons with direct connection and indirect connection. On this basis, the far induction network and the near induction network (NINN) are constructed by using hyperbolic tangent memristors to explore the influence of electromagnetic induction between neurons at different positions on the dynamic behavior of attractors. NINN exhibits more complex attractor structures and wider chaotic parameters, and also displays a heterogeneous coexisting attractor of limit cycles and chaos under network parameter control. By varying the parameters, coexisting chaotic attractors can be synthesized into a double scrolls attractor, and their oscillation amplitude can be controlled without changing the chaotic characteristics. The type of attractors in human brain determines the clarity of memory. These complex dynamic behaviors demonstrate that near induction has a more pronounced effect on the forgetting and disappearance of memory compared to far induction. Finally, a circuit using switches to change the type of electromagnetic induction is constructed and the results are verified.
Experimental analysis of ice crystal size–velocity correlation in icing wind tunnel with digital holographic particle tracking velocimetry
Authors: Wang Boyi , Wu Yingchun , Zhang Letian , Huang Xinyuan , Guo Xiangdong , Song Xiaoming , Bai Pengbo , Shi Pan , Zhu Shimin , Zhang Qian , Liu Kai , Wu Xuecheng
Published: August 2024

The ice crystal icing in aero-engines poses a significant threat to aircraft flight safety, and investigating the correlation between ice crystal size and velocity in icing wind tunnels is essential for correlating ground tests with flight conditions. In this paper, a digital holographic particle tracking velocimetry system is developed and integrated with an icing wind tunnel, and the ice crystal size and velocity are simultaneously measured in experiments at four different wind speeds. The velocity difference between the ice crystal and wind has been experimentally observed, and it increases with both the ice crystal size and wind speed. The normalized velocities of the ice crystals by the wind speeds decrease with size, and the maximum velocity difference in the experiments reaches 28% of the wind speed. Additionally, quantitative correlations between ice crystal size and normalized velocity based on the power function and polynomial model are established. The relationship between the particle Reynolds number of ice crystal and size is also analyzed, resulting in the development of a model based on the power function, and the power index ranges from 1.51 to 1.64. These findings will provide valuable assistance in the calibration and commissioning of the ice crystal simulation system in icing wind tunnels, as well as in exploring the correlation between ground icing tests and flight and in developing corresponding models.
Effective InAsP dislocation filtering layers for InP heteroepitaxy on CMOS-standard (001) silicon
Authors: Liu Shangfeng , Ratiu Bogdan-Petrin , Jia Hui , Yan Zhao , Wong Ka Ming , Martin Mickael , Tang Mingchu , Baron Thierry , Liu Huiyun , Li Qiang
Published: August 2024

In this work, we report InAsP-based dislocation filter layers (DFLs) for InP heteroepitaxy on CMOS-standard (001) Si substrates, demonstrating a threading dislocation density of 3.7 × 107 cm−2. The strain introduced by InAsP induces dislocation bending at the InAsP/InP interface, thereby facilitating the reaction and annihilation of dislocations during their lateral glide. Concurrently, the InP spacer exhibits tensile strain, leading to the formation of stacking faults (SFs). With a comprehensive analysis utilizing x-ray diffraction, electron channeling contrast imaging, and transmission electron microscopy, the effects of DFL-induced strain on dislocations and SFs are investigated. Fine-tuning the strain conditions allowed low-dislocation-density while SF-suppressed, anti-phase boundary free InP on Si. This work, therefore, provides a useful buffer engineering scheme for monolithic integration of InP-based electronic and photonic devices onto the industry-standard silicon platform.
Two-inlet lagoon systems: Interaction between basins and effects on tidal prisms
Authors: Petti M. , Bosa S. , Pascolo S.
Published: August 2024

In a lagoon basin, the tidal prism is related to the section of its inlet by a simple monomial relationship [L. J. LeConte, “Discussion on the paper, ‘notes on the improvement of river and harbor outlets in the United States,’ by D. A. Watt.” Trans. ASCE 55, 306–308 (1905); M. P. O'Brien, “Estuary tidal prism related to entrance areas,” Civil Eng. 1(8), 738–739 (1931); and J. T. Jarrett, Tidal Prism - Inlet Area Relationships (Coastal Engineering Research Center, US Army Corps of Engineers, Fort Belvoir, VA, 1976)]. Although it is not dimensionally correct and there are sophisticated models in two or three dimensions, this relationship is widely used because of its simplicity. Having a simple relationship can be very important, especially when it is necessary to make quick, albeit approximate, evaluations. To maintain this simplicity, the same monomial relationship is often used in multi-inlet lagoons, even if the initial assumptions are not fully met. Another difficulty in applying a monomial relationship to a multi-inlet lagoon is the definition of the area of each basin. In this paper, we propose a simple Eulerian, hydrodynamic, one-dimensional approach based on the dynamic response of a nonlinear harmonic system and a harmonic analysis of the interaction between two basins in a lagoon system. With such an approach, the definition of the basin surface is overcome simply by working on topographic control basins. The study leads to the definition of a relatively simple relationship for the estimation of tidal prisms, while maintaining the flexibility of a monomial relationship. If the geometrical characteristics and the bottom friction of the inlet channel, the topographic surface of the basins and the amplitude of the tide in the open sea are known, this relationship can be used to estimate the tidal prism in individual basins. The application of this relationship to two-dimensional numerical cases and real multi-inlet lagoons shows good agreement with experimental data.
All-optical method to directly measure the pressure–volume–temperature equation of state of fluids in the diamond anvil cell
Authors: Proctor J. E. , Robertson C. E. A. , Jones L. J. , Phillips J. , Watson K. , Dabburi Y. , Moss B.
Published: August 2024

We have developed a new all-optical method to directly measure the pressure–volume–temperature (PVT) equation of state (EOS) of fluids and transparent solids in the diamond anvil high pressure cell by measuring the volume of the sample chamber. Our method combines confocal microscopy and white light interference with a new analysis method, which exploits the mutual dependence of sample density and refractive index: Experimentally, the refractive index determines the measured sample chamber thickness (and therefore the measured sample volume/density), yet the sample density is by far the dominant factor in determining the variation in the refractive index with pressure. Our analysis method allows us to obtain a set of values for the density and refractive index, which are mutually consistent and agree with the experimental data within error. We have conducted proof-of-concept experiments on a variety of samples (H2O, CH4, C2H6, C3H8, KCl, and NaCl) at ambient temperature and at high temperatures up to just above 500 K. Our proof-of-concept data demonstrate that our method is able to reproduce known fluid and solid EOS within error. Furthermore, we demonstrate that our method allows us to directly and routinely measure the PVT EOS of simple fluids at GPa pressures up to, at least, 514 K (the highest temperature reached in our study). A reasonable estimation of the known sources of error in our volume determinations indicates that the error is currently ±2.7% at high temperature and that it is feasible to reduce it to ca. ±1% in future work.
Numerical simulations of secondary atomization characteristics of shear-thinning kerosene gels
Authors: Li Meng-Ge , Li Yu-Bai , Yuan Wen-Jun , He Yong , Massoudi Mehrdad , Feng Feng , Wu Wei-Tao
Published: August 2024

Owing to their unique non-Newtonian characteristics, gel propellants have become a new type of fuel with promising applications in the aerospace industry. However, the complex rheological properties and high viscosity of gels pose significant challenges for flow control in gel engines, particularly in terms of fuel atomization and combustion efficiency. Focusing primarily on kerosene gel, this study investigates the secondary atomization characteristics of shear-thinning droplets, where the volume of fluid method is employed to capture interface dynamics on adaptive grids, and the viscosity of the gel is described by a power-law model. The accuracy of the numerical model is validated by comparing it with the experimental observations of the breakup process of 1% silica kerosene gel droplets. Numerical simulations are conducted to analyze the droplet breakup processes and formation mechanisms under bag, multimode, and shear breakup. Compared to kerosene, the apparent viscosity distribution inside the kerosene gel droplets is non-uniform, and the inhibition of viscous force delays the breakup time and reduces the droplet deformation, thereby affecting the transition of the breakup mode. By varying the Weber number, We, the rheological parameters, and the density ratio, the quantitative effects of these factors on droplet deformation, centroid velocity, average viscosity, the breakup time, etc. are revealed. The results indicate that the breakup becomes more severe with increasing We number, resulting in larger deformation and a greater number of smaller droplets; the rheological parameters significantly affect the droplet breakup by altering the fluid viscosity; moreover, under the same flow condition, the higher the density ratio, the more difficult it is for the droplet to break up; however, on dimensionless scales, the effect of density ratio appears weak. Additionally, a breakup regime diagram is constructed in the We–Oh (Ohnesorge) number space for low Weber numbers. This study validates the numerical method for simulating the secondary atomization of kerosene gel propellants, providing a thorough analysis of three breakup mechanisms and the impact of key parameters on kerosene gel droplets. These insights offer a theoretical foundation for the optimization of gel propellants, aiding in the development of efficient and stable propulsion systems.
Relative kinetic stability of defect patterns in two-dimensional nematic liquid crystals with rectangular confinement
Authors: Zhang Xiao-Jie , Sun Yu-Wei , Li Zhan-Wei , Sun Zhao-Yan
Published: August 2024

Guiding and dynamically modulating topological defects are critical challenges in defect engineering of liquid crystals. Here, we employ molecular dynamics simulations to investigate the transition dynamics and relative kinetic stability of defect patterns in two-dimensional nematic Gay–Berne liquid crystals confined within rectangular geometries. We observe the formation of various defect patterns including long-axis, diagonal, X-shaped, composite, and bend configurations under different confinement conditions. The competition between boundary effects and the uniformity of nematic orientation induces the continuous realignment of liquid crystal molecules, facilitating the spatially continuous transformation of defect patterns over time. This transition involves changes in both defect types and their locations, typically initiating from defect regions. Furthermore, we demonstrate that the relative stability of these defect patterns can be effectively controlled by adjusting confinement parameters and external field conditions. Our findings provide fundamental insights into the transition kinetics of defect patterns in confined nematic liquid crystals, thereby enhancing our ability to manipulate topological defects for advanced applications.
Syphilis point-of-care tests: an Australian perspective
Authors: Pérez Chacón Gladymar , Saha Amit , Phillips Emily , Guy Rebecca , Applegate Tanya L. , Causer Louise , McGregor Skye , Hengel Belinda
Published: August 2024

Syphilis is a sexually and vertically transmitted infection caused by Treponema pallidum. Although preventable and curable, syphilis remains a public health challenge worldwide, disproportionately affecting communities who experience marginalisation, stigma, and discrimination. Syphilis point-of-care (POC) tests may provide a tool to enhance patient access and timely treatment. In Australia, syphilis POC tests have been incorporated into various public health screening strategies and implemented across different jurisdictions as part of the nationwide response to an expanding syphilis epidemic. These programmes use a highly sensitive and specific POC lateral flow immunoassay test that detects antibodies to T. pallidum, and have largely focused on outbreaks areas, where the burden of infectious syphilis is highest and the distance to centralised laboratories remains significant. The COVID-19 pandemic has resulted in substantial advancements in diagnostic development capabilities with many companies now pivoting to development of POC tests for sexually transmitted infections (STIs). Here we summarise types of syphilis POC tests available, their role in clinical and public health strategies in Australia, and frameworks for selection of POC tests in screening programmes.