bluuebunny/crossref_metadata_2025 huggingface dataset:
The AMBRE Project: Lead abundance in Galactic stars
Authors: Contursi G. , de Laverny P. , Recio-Blanco A. , Molero M. , Spitoni E. , Matteucci F. , Cristallo S.
Published: August 2024

Context. The chemical evolution of neutron capture elements in the Milky Way is still a matter of debate. Although more and more studies investigate their chemical behaviour, there is still a lack of a significant large sample of abundances of a key heavy element: lead.

Aims. Lead is the final product of the s-process nucleosynthesis channel and is one of the most stable heavy elements. The goal of this article is to present the largest catalogue of homogeneous Pb abundances, in particular for metallicities higher than −1.0 dex, and then to study the lead content of the Milky Way.

Methods. We analysed high-resolution spectra from the ESO UVES and FEROS archives. Atmospheric parameters were taken from the AMBRE parametrisation. We used the automated abundance method GAUGUIN to derive lead abundances in 653 slow-rotating FGK-type stars from the 368.34 nm Pb I line.

Results. We present the largest catalogue of Local Thermodynamic Equilibrium (LTE) and non-LTE lead abundances ever published with metallicities ranging from −2.9 to 0.6 dex and [Pb/Fe] from −0.7 to 3.3 dex. Within this sample, no lead-enhanced Asymptotic Giant Branch (AGB) stars were found, but nine lead-enhanced metal-poor stars ([Pb/Fe] > 1.5) were detected. Most of them were already identified as carbon-enhanced metal-poor stars with enrichments in other s-process species. The lead abundance of 13 Gaia Benchmark Stars are also provided. We then investigated the Pb content of the Milky Way disc by computing vertical and radial gradients and found a slightly decreasing [Pb/Fe] radial trend with metallicity. This trend together with other related ratios ([Pb/Eu], [Pb/Ba], and [Pb/α]) are interpreted thanks to chemical evolution models. The two-infall model closely reproduces the observed trends with respect to the metallicity. It is also found that the AGB contribution to the Pb Galactic enrichment has to be strongly reduced. Moreover, the contribution of massive stars with rather high rotational velocities should be favoured in the low-metallicity regime.
X-ray photo-desorption of NH3 and N2 from ammonia ices: Mechanisms and yields in protoplanetary disks
Authors: Torres-Díaz D. , Basalgète R. , Amiaud L. , Philippe L. , Michaut X. , Fillion J.-H. , Lafosse A. , Bertin M.
Published: August 2024

Context. Ammonia is detected both in the gas phase and in the ices of protoplanetary disks. However, its gas phase abundances are still difficult to reproduce via chemical modelling when only the thermal-, UV photon-, and cosmic ray-induced processes are considered. Among other non-thermal mechanisms, X-ray photo-desorption is a relevant pathway to maintaining a budget of molecules in the gas of disks. However, no quantitative data are available to constrain its efficiency in the case of ammonia-containing ices.

Aims. We studied the desorption induced by soft X-rays from ammonia ices to determine the photo-desorption yields of neutral molecules that can be applied to the conditions of protoplanetary disks. We also aim to identify the desorption mechanisms at play.

Methods. Pure ammonia ices were deposited at 23 or 75 K and irradiated between 395 and 435 eV, with monochromatic synchrotron light. Desorption of neutral molecules and fragments was detected using a quadrupole mass spectrometer, calibrated to obtain des-orption yields. These values were extrapolated and the spectrum of a protoplanetary disk was used to extract average astrophysical desorption yields.

Results. Photo-desorption from NH3 ices is dominated by the desorption of neutral NH3 and N2 molecules. The desorption mechanism mostly involves the thermalisation of Auger electrons in the ice, although resonant phenomena also contribute near the N 1s ionisation edge. The NH3 photo-desorption is independent of ice morphology and irradiation temperature. Contrary to NH3 desorption, N2 desorption is sensitive to the photon fluence received by the ice. Average photo-desorption yields derived using the TW Hya X-ray spectrum reveal that the NH3 photo-desorption would be four to six times more efficient than that of H2O. This could be at the origin of unexplained high NH3/H2O abundance ratios predicted in the disk around TW Hya. This result ought to be confirmed by the study of mixed water-ammonia ices.
Soft X-ray emission from the classical nova AT 2018bej
Authors: Tavleev A. , Ducci L. , Suleimanov V. F. , Maitra C. , Werner K. , Santangelo A. , Doroshenko V.
Published: August 2024

Context. Classical novae are known to demonstrate a supersoft X-ray source (SSS) state following outbursts. This state is associated with residual thermonuclear burning on the white dwarf (WD) surface. During its all-sky survey (eRASS1), the eROSITA telescope on board the Spectrum-Roentgen-Gamma observatory discovered a bright new SSS, whose position is consistent with the known classical nova AT 2018bej in the Large Magellanic Cloud. There were two eROSITA spectra obtained during the eRASS1 and eRASS2 monitoring epochs and one XMM-Newton grating spectrum close to the eRASS1 epoch.

Aims. We aim to describe the eROSITA and follow-up XMM-Newton spectra of AT 2018bej with our local thermodynamic equilibrium (LTE) atmosphere models. We focussed on the evolution of the hot WD properties between the eRASS1 and eRASS2 epochs, especially with respect to the change in carbon abundance.

Methods. A grid of LTE model atmosphere spectra was calculated for different values of the effective temperature (from Teff = 525 to 700 kK in steps of 25 kK), surface gravity (six values), and chemical composition, assuming approximately equal hydrogen and helium number fractions, and five different values of carbon and nitrogen abundances.

Results. Both eRASS1 and XMM 0.3–0.6 keV spectral analyses yield a temperature of the WD of Teff~ 600 kK and a WD radius of 8000–8700 km. A simultaneous fitting of the eROSITA spectra for two epochs (eRASS1 and eRASS2) with a common WD mass parameter demonstrates a decrease in Teff, accompanied by an increase in the WD radius and a decrease in the carbon abundance. However, these changes are marginal and remain within the errors. The derived WD mass is estimated to be 1.05–1.15 M⊙.

Conclusions. We traced a minor evolution of the source on a half-year timescale accompanied by a decrease in the carbon abundance and concluded that LTE model atmospheres can be used to analyse the available X-ray spectra of classical novae during their SSS state.
Validating the clustering predictions of empirical models with the FLAMINGO simulations
Authors: Contreras Sergio , Angulo Raul E. , Chaves-Montero Jonás , Kugel Roi , Schaller Matthieu , Schaye Joop
Published: August 2024

Context. Mock galaxy catalogues are essential for correctly interpreting current and future generations of galaxy surveys. Despite their significance in galaxy formation and cosmology, little to no work has been done to validate the predictions of these mocks for high-order clustering statistics.

Aims. We compare the predicting power of the latest generation of empirical models used in the creation of mock galaxy catalogues: a 13-parameter halo occupation distribution (HOD) and an extension of the SubHalo Abundance Matching technique (SHAMe).

Methos. We built GalaxyEmu-Planck, an emulator that makes precise predictions for the two-point correlation function, galaxy-galaxy lensing (restricted to distances greater than 1 h−1 Mpc in order to avoid baryonic effects), and other high-order statistics resulting from the evaluation of SHAMe and HOD models.

Results. We evaluated the precision of GalaxyEmu-Planck using two galaxy samples extracted from the FLAMINGO hydrodynamical simulation that mimic the properties of DESI-BGS and BOSS galaxies, finding that the emulator reproduces all the predicted statistics precisely. The HOD shows a comparable performance when fitting galaxy clustering and galaxy-galaxy lensing. In contrast, the SHAMe model shows better predictions for higher-order statistics, especially regarding the galaxy assembly bias level. We also tested the performance of the models after removing some of their extensions, finding that we can withdraw two (out of 13) of the HOD parameters without a significant loss of performance.

Conclusions. The results of this paper validate the current generation of empirical models as a way to reproduce galaxy clustering, galaxy-galaxy lensing, and other high-order statistics. The excellent performance of the SHAMe model with a small number of free parameters suggests that it is a valid method to extract cosmological constraints from galaxy clustering.
IT-Angriffe an Kliniken
Authors: Pfenninger Ernst , Königsdorfer Manuel
Published: August 2024

Kliniken gehören per definitionem zur kritischen Infrastruktur eines Landes. Vermehrt sind in den vergangenen Jahren Krankenhäuser Ziel von Hackerangriffen mit der Folge einer wochen- bis sogar monatelangen Beeinträchtigung ihrer Handlungsfähigkeit geworden. Gemäß der „Nationalen Strategie zum Schutz Kritischer Infrastrukturen (KRITIS-Strategie)“ sind Kliniken gesetzlich verpflichtet, dagegen Vorsorge zu treffen. Dazu sollten IT-abhängige Prozesse in einer Klinik evaluiert, definiert und Ausfallkonzepte erarbeitet werden, um auf einen Cyberangriff vorbereitet zu sein. Spezifisch auf einen EDV-Ausfall zugeschnittene Notfallpläne sollten in allen IT-abhängigen Bereichen einer Klinik erstellt und vorgehalten werden. Zudem sollten papierbasierte Ersatzlösungen, wie z. B. Anforderungsbelege für Diagnostik- oder Konsilleistungen, abteilungsspezifische Notfalldokumente und Patientendokumentationskurven an einem gut zugänglichen und den Mitarbeitenden des jeweiligen Bereichs
bekannten Ort vorgehalten werden. Die vollständige Wiederherstellung eines Kliniknetzwerks nach einem Cyberangriff erfordert häufig eine umfassende Wiederherstellung zahlreicher IT-Systeme. Dies kann u. U. Wochen bis Monate dauern. Wenn das Krankenhaus über solide Pläne zur Cyber-Notfallvorsorge verfügt, die regelmäßige Scans und Backups in Echtzeit umfassen, können eine Stabilisierung und ein schnelleres Wiederanlaufen des Betriebs möglich sein.
A Retrospective Study of Risk Factors Associated with Refracture after Repair of Radial–Ulnar Fractures in Small-Breed Dogs
Authors: Muroi Norihiro , Kanno Nobuo , Harada Yasuji , Hara Yasushi
Published: August 2024

Objective The aim of this study was to identify risk factors for refracture after radial union in small-breed dogs.

Study Design In our retrospective study, medical records of radial–ulnar fracture cases in small dogs treated with plates and screws were reviewed. General information and postoperative course (days until confirmed radial fracture healing, with or without ulnar union, time to final follow-up, with or without plate removal and refracture) were recorded. The fracture line location, screw positions, radial thickness and width, and pixel values throughout the postoperative periods were obtained from the radiographs. The affected limbs were classified into non-plate removal (P) and plate removal (R) groups.

Results Refracture occurred in 5 of the 141 limbs at the most distal screw in the P group and 5 of the 40 limbs at the same site as the initial fracture in the R group. Multivariate analysis indicated that refracture was linked to the amount of relative change with growth in the position of the most distal screw in the P group, with pixel value and radial thickness ratios at the same site as the initial fracture in the R group.

Conclusion Reducing the screw diameter relative to the radial width to the appropriate extent may be considered in cases where the screw positioned at the most distal end of the radius is expected to be relatively proximal as the distal radius grows; not removing the plate may be considered in cases with a decreased radial thickness or bone mineral density beneath the plate during plate removal.
Enlivening a place brand inclusively: evidence from ten European cities
Authors: Lemmetyinen Arja , Nieminen Lenita , Aalto Johanna , Pohjola Tuomas
Published: August 2024

This study contributes to the stream of research investigating the influence of the creative sector on the development of cities and the importance of place branding to local development. Place branding increasingly influences the competitiveness and attractiveness of cities. We examined ten European cities as creative places and how integrating creative economy strategies, social inclusion, and sustainable practices into city branding contributes to differentiation and competitiveness. The current research contributes to the research area by examining certain cities in the context of the creative economy and investigating how, as creative brands, they can be differentiated from their competitors by utilizing inclusive planning of the image of the place.
Identifying and preventing future forms of crimes using situational crime prevention
Authors: Johnson Shane D.
Published: August 2024

Traditional crime has been falling for some time in most countries. However, developing technologies and our use of them are creating new opportunities for offending. For example, estimates from the Crime Survey of England and Wales indicate that in the UK, online fraud and related offences account for as many crimes as do “traditional” offences. To date, academia, law enforcement and governments have been reactive both in terms of identifying new and emerging forms of offending and in developing approaches to address them. In this paper, I will discuss the future crime agenda, and how futures thinking can help identify future crime opportunities and security threats including online fraud, crimes involving artificial intelligence, and crime in the metaverse. The paper will close with a discussion of the implications for theory and crime prevention.
Design and characteristics of a fiber laser powered repetitive micro-plasma jet triggered gas switch
Authors: Tian Sitong , Chen Li , Cao Haojie , Zhang Xiaoqian
Published: August 2024

To satisfy the need for low jitter in gas switches at repetition rate and enhance insulation reliability during high voltage operation of the trigger, we propose a micro-jet triggering system. This system requires less energy and can use a laser power supply as an energy source. It effectively improves the insulation stability of the trigger when working at high potentials and achieves a good triggering effect with low jitter at low working coefficients. The breakdown characteristics were tested by double-pulse experiments. Ensuring the same operating conditions for both pulses, the pulse interval was varied to obtain the breakdown voltage dispersion at different repetition rates. The results indicate that the dispersion of the breakdown voltages can reach 0.16% at a frequency of 50 Hz with a pulse front of 30 μs, representing an order of magnitude reduction compared to the 1.45% at switching self-breakdown, and decreases further as the air pressure rises. In addition, the size of the microcapillary has an impact on the dispersion of breakdown voltage. It was found that for a range of lengths from 2 to 6 mm and aperture sizes from 80 to 400 μm, the trigger jitter was lower when the length was larger and the aperture was smaller. Furthermore, a trigger life test was performed on the ceramic capillary, and after one million triggers, the system remained stable with no degradation in trigger performance.
AI can solve the crystallographic phase problem
Authors: Lopatka Alex
Published: August 2024

A neural network identifies molecular crystal structures with just a fraction of the data that other methods need.
Oral health status and oral health-related quality of life: a cross-sectional study of clients in an Australian opioid treatment program
Authors: Wong Grace , Venkatesha Venkatesha , Montebello Mark Enea , Masoe Angela , Cheng Kyle , Cook Hannah , Puszka Bonny , Cheng Anna
Published: August 2024

Background Individuals with opioid dependence often experience poor oral health, including dental decay, periodontal disease and mucosal infection, frequently exacerbated by factors such as smoking, alcohol consumption, inadequate oral hygiene and low utilisation of oral health services. This study aimed to assess oral health status and oral health-related quality of life (OHRQoL) among opioid-dependent individuals and explore their potential associations. Methods Participants enrolled in an opioid treatment program (OTP) at three Australian urban clinics were assessed using the validated Oral Health Assessment Tool (OHAT) and Oral Health Impact Profile (OHIP-14). Results The average age of the 75 participants was 44.7 years, with 45% receiving opioid treatment for over 5 years. Dental decay and inadequate oral hygiene were prevalent. Mean OHAT and OHIP-14 scores were 6.93 and 20.95 respectively, indicating moderate oral health severity and poor OHRQoL. Physical pain and psychological discomfort significantly impacted participants’ quality of life, with the effects being particularly pronounced for those aged 30 and above. An exploratory analysis revealed a strong correlation between OHAT and OHIP-14 severity scores, with a one-point increase in OHAT associated with 1.85 times higher odds of a lower OHRQoL (odds ratio = 1.85, 95% confidence interval: 1.38–2.49, P = <0.001). Conclusions These findings underscore the multifaceted impact of oral health on the well-being of OTP clients. Routine dental check-ups, education on oral hygiene practices and timely treatment for oral health problems are crucial recommendations based on this study. Such measures hold the potential to enhance the quality of life for individuals attending OTPs.
Past fire shaping future fuel: influence of recent fire history on forest foliage chemistry
Authors: Schneider Margot A. , Cary Geoffrey J. , Bowd Elle J. , Foster Claire N.
Published: August 2024

Background Knowledge of how fire regimes influence flammability, and its role in shaping future fire regimes, exists mostly at species composition and ecosystem levels. The effect of fire regimes on fuel at the chemical level is poorly known. Aim We aimed to empirically investigate the association between recent fire history and forest foliage chemistry; and to explore potential implications for forest fuel flammability. Methods Using an orthogonal study design, we investigated the effects of fire frequency and time since fire on the chemical composition of Eucalyptus pilularis leaves from forest canopies and surface litter in south-eastern Australia. Key results We found high fire frequency (fire-return interval 10–13 years) was associated with higher C:N, C:P, and C:K ratios in E. pilularis surface litter, and higher C:P in canopy leaves. Conclusions Nutrients including nitrogen and phosphorous reduce flammability of plant tissues, and hence, the observed differences in leaf nutrients between high and low fire frequency sites could have important implications for future flammability of these forests. Implications Our study has demonstrated a relationship between fire frequency and leaf nutrient stoichiometry, which may act as a mechanism through which repeated fires could increase fuel flammability. This warrants further investigation in other environments.
Heisenberg spin chain with random-sign couplings
Authors: Fava Michele , Jacobsen Jesper Lykke , Nahum Adam
Published: August 2024

We study the 1D quantum Heisenberg chain with randomly ferromagnetic or antiferromagnetic couplings [a model previously studied by approximate strong-disorder renormalization group (RG)]. We find that, at least for sufficiently large spinS, the ground state has “spin glass” order. The spin waves on top of this state have the dynamical exponentz=3/2, intermediate between the valuesz= 1 of the antiferromagnet andz= 2 of the ferromagnet. Density matrix renormalization group (DMRG) simulations are in good agreement with the analytical results for spinsS= 1 andS=3/2. The caseS=1/2shows large finite size effects: We suggest that this case is also ordered, but with a small ordered moment.
Regrounding work in elite discourse
Authors: Thurlow Crispin , Jaworski Adam
Published: August 2024

This paper considers the interplay of small-scale pragmatic actions and large-scale discursive formations;
specifically, we examine frame-shifting and keying in the globally syndicated BBC television show Amazing Hotels: Life
Beyond the Lobby. Focusing on the fourth season of Amazing Hotels, which broadcast in 2021, we
document how work and workers are staged for entertainment as quintessential examples of a non-serious frame that Goffman called
regroundings. We argue that this particular keying of other people’s labour as play is further evidence for
how mediatized representations of super-elite lifestyles normalize inequality by “democratizing” privilege and amplifying
entitlement.
Words worth noticing
Authors: Feddersen Richard , Plews John L. , Misfeldt Kim
Published: August 2024

We use guided language learning journals written in second language (L2) German by Canadian undergraduates while
studying in Germany and apply structural linguistic analyses and Cognitive Discourse Analysis to examine lexical items students
attend to and, drawing on Bloom’s taxonomy, trace their learning process through their narrative language use. We show that
lexical acquisition in study abroad is diverse and complex, observing a preference for meaning over function, and attention to
items that were highly specialized or personally meaningful. Students also engaged in what we call private languaging in a safe
environment serving to engage language to think through and construct meanings as planning for future interaction. We shed light
on the process of language development during study abroad, refine quantitative understandings of L2 gains in previous studies
through our qualitative approach, and expand our knowledge of how to assist learners to optimize the personal linguistic benefits
of studying abroad.
Perspective for in-volume machining of solid materials by undersurface focusing of x-ray pulses
Authors: Inoue Ichiro , Ziaja Beata
Published: August 2024

In this perspective article we propose and discuss a possible technique of in-depth material processing based on undersurface focusing of intense x-ray pulses. Currently, x-ray free-electron lasers can produce such intense x-ray pulses with femtosecond pulse durations, reaching intensities sufficiently high to cause ultrafast melting of a material after a single laser shot. Here, on the example of silicon crystal we will demonstrate that with a proper choice of pulse parameters and focusing parameters, the already existing nanofocusing setup has a capability to focus hard x rays down to several hundreds micrometers below the material surface. This can trigger the required structural modification in the focal point, without damaging the material above. Potential applications of the new technique are discussed.
Quantum states and spectra of small cylindrical and toroidal lattices
Authors: Brooks Caelan , Das Kunal K
Published: August 2024

We examine the spectrum and quantum states of small lattices with cylindrical and toroidal topology subject to a scalar gauge potential that introduces a position dependent phase in the inter-site coupling. Equivalency of gauges assumed in infinite lattices is generally lost due to the periodic boundary conditions, and conditions that restore it are identified. We trace the impact of various system parameters including gauge choice, boundary conditions and inter-site coupling strengths, and an additional axial field. We find gauge dependent appearance of avoided crossings and persistent degeneracies, and we show their impact on the associated eigenstates. Smaller lattices develop prominent gaps in spectral lines associated with edge states, which are suppressed in the thermodynamic limit. Toroidal lattices have counterparts of most of the features observed in cylindrical lattices, but notably they display a transition from localization to delocalization determined by the relation between the field parameter and the number of lattice sites.
Non-contact measurement of torque in rotational truck flywheel using resistance strain gauges based on wireless telemetry system
Authors: Ren Yingming , Yan Shanheng , Li Jianfeng , Xie Xin , Sun Houhua , Sun Wanyu , Zhang Zongyang
Published: August 2024

Torque is an important parameter that determines the rotational characteristics of a flywheel. Installing a signal transmission and power supply device equipped with sensors on a rotational flywheel presents challenges due to the limited space behind the engine crankshaft. To overcome these problems, this study proposes an approach to measure flywheel torque using strain gauges and a wireless telemetry system based on induction. Eight double-shear strain gauges are attached to both the front and back of the modified flywheel significantly simplifying the complex problems associated with torque measurement and signal transmission. We developed a model for analysing torque waveforms to verify the reliability of road test data across various test cycles. The torque characteristics of the flywheel were analysed at different rotational speeds. During vehicle operation, the torque measurement error margin of this sensor was less than 2.57%. This study demonstrates that using resistance strain gauges with a telemetry system for measuring flywheel torque is reliable and enhances the understanding of the mechanical performance of the flywheel.
Charging properties of atactic poly(styrene) microfibre mats charged with electrospinning and corona charging
Authors: Kaneko Mitsuo , Takagaki Kenichi , Tsuchimoto Rintaro , Ishii Yuya
Published: August 2024

Electrospinning is a versatile technique widely used to produce polymer fibres with diameters ranging from several micrometres to tens of nanometres. This unique technique enables the production of thin fibres and charges the fibres in parallel. However, precise comparisons between electrospinning and other charging techniques have been limited. In this study, the charging properties of electrospun microfibre mats fabricated using atactic poly(styrene) (aPS) were compared with those of corona-charged microfibre mats fabricated using the same material (aPS) and possessing the same structure. The results showed that the surface potentials of electrospun aPS fibre mats were approximately three times higher than those of corona-charged fibre mats, demonstrating that a significantly large amount of charge could be stored in electrospun fibre mats. A large amount of stored charge was maintained even after 240 d of storage in low-humidity, atmospheric, and high-humidity environments. Furthermore, mathematical models explaining the effective surface charge densities of electrospun and corona-charged fibre mats were proposed using the recently proposed model of stored charge distribution in fibre mats. Therefore, the clarified unique charging properties of electrospun aPS microfibre mats originally charged via electrospinning pave the way for the development of appropriate applications of electrospun charged polymer microfibres, submicrofibres, and nanofibres.
Nondestructive evaluation of microstructure and mechanical property of post-processing annealed selective laser melted 316L stainless steel by laser ultrasonics
Authors: Zheng Lei , Yin Anmin , Xu Da , Lu Yujie , Liao Wenchao , Chen Hou , He Yeqing , Xia Zhenxin , Ma Kaibo , Yan Xuejun
Published: August 2024

By using the laser ultrasonics nondestructive technology, combined with the microstructure and mechanical property of post-processing annealed selective laser melted 316L stainless steel characterized by scanning electron microscopy (SEM), electron backscattering diffraction (EBSD), and mechanical property testing, selective laser melted 316L stainless steel after post-processing annealing was evaluated. The results show that the frequency domain attenuation coefficient of ultrasonic waves is positively correlated with the average grain size; the time domain attenuation coefficient of ultrasonic waves is negatively correlated with the low angle boundary content. The tensile strength has a good correlation with the time domain attenuation coefficient and wave speed, the correlation coefficients R2 are 0.95 and 0.89 respectively; the yield strength correlates with the time domain attenuation coefficient, the correlation coefficient R2 is 0.76; the elongation has a good correlation with the frequency domain attenuation coefficient and wave speed, the correlation coefficient R2 is 0.90 and 0.86 respectively.
Fast detection of humidity sensor with a weakly coupled fiber coated with carbomer
Authors: Shi Yueyan , Li Shuang , Zhang Xiajing , Zhang Benyu , Bao Yanjun , Yu Xiantong , Zhou Shiqing , Chang Min , Guo Jiachen
Published: August 2024

Humidity, as one of the basic environmental physical quantities, is essential in medical monitoring, food production and pharmaceutical industries.Fast and highly sensitive humidity sensing technology has become an urgent need in areas such as medical monitoring. We proposed and realized a novel coupled fiber-optic humidity sensor based on double tapered fiber twisted weakly coupled structure coated with carbomer film. The sensor adopts 2 × 2 coupler structure with waist diameter of 10 μm. The Carbomer film is coated in the weakly coupled area to improve the sensitivity of the sensor, and the thickness of this coating is about 79.2 nm. The sensor provides linear sensing over a relative humidity range of 40%–65% RH, with a dynamic response time of 208 ms and a recovery time of 464 ms. The sensitivity of the sensor is up to −0.28 dB/%RH and the linearity of the sensor is as high as 99.89%. Moreover, the sensor has good stability, reversibility, and low temperature crosstalk. Based on these characteristics, it can be expected that the sensor will bring a great breakthrough in applications where sensitive monitoring of humidity is required.
Fitting x-ray diffraction peaks by a genetic algorithm and Monte Carlo Markov Chain procedure
Authors: Durán González David , Sánchez-Bajo Florentino
Published: August 2024

A fitting procedure based on the use of the Genetic algorithms (GA) and the Markov Chain Monte Carlo (MCMC) bayesian technique is proposed for the modelization of the x-ray diffraction peaks by using the usual standard bell-type functions (pseudo-Voigt, Voigt, etc). The method has been tested with simulated Voigt-shaped profiles at different overlapping degrees and the results have been compared with those obtained by means of the classical Levenberg-Marquardt algorithm, showing its reliability.
Microplasma-assisted synthesis of chromium oxide nanoparticles and their biological activities
Authors: Naeem M , Zahir Sania , Díaz Guillén J C , Díaz-Elizondo José , Iqbal Tariq , Rashid Umair , Nazer Sadia , Iqbal Javed
Published: August 2024

Chromium oxide nanoparticles are of significant interest and are widely used in numerous applications due to their exclusive physicochemical properties, including wide bandgap, increased stability, high melting temperature, and antibacterial and antifungal properties. In this study, the atmospheric pressure microplasma technique is used to synthesize chromium oxide nanoparticles by changing the precursor concentration (10, 15, and 20 mM). The nanoparticles are characterized by numerous techniques, including XRD, SEM, FTIR, UV-visible spectroscopy, RAMAN Spectroscopy, and antibacterial and antifungal activities. It is observed in XRD analysis that different phases of chromium oxide nanoparticles, Cr2O3 and CrO2, can be attained when the precursor concentration is changed. As a result, their efficiency can be tuned to different applications. The UV visible results depict that the band gap is reduced by increasing the precursor concentration (Cr(NO3)3.9H2O). The FTIR analysis is used to determine the surface functional groups of synthesized nanomaterials. Our results demonstrate the potential of chromium oxide nanoparticles as effective antibacterial and antifungal agents. Specifically, we found that these nanoparticles exhibit a strong antibacterial impact on gram-negative bacteria and a reasonable effect on gram-positive bacteria under some synthesis conditions. Moreover, they depict significant anti-fungal activity against two pathogenic fungus species, Penicillin Digitatum, and Rhizopus stolonifers. These promising findings, particularly for nanoparticles prepared at the concentration of 10 mM precursor with the Cr2O3 phase, reveal that these nanoparticles can be used efficiently for antibacterial (particularly gram-negative bacteria) and antifungal activities.
WO3/Cu2O-CuO and WO3/Au/Cu2O-CuO heterojunctions photocatalysts for self-cleaning and photocatalytic degradation of organic pollutants applications
Authors: Mindil A , Mohamed S H , Alsubaie Abdullah Saad , Rabia Mohamed
Published: August 2024

In this work, a high-performance WO3/Au/Cu2O-CuO heterojunctions was deposited via dc reactive magnetron sputtering, which displayed superhydrophilicity conversion and superior photocatalytic performance for the degradation of methylene blue. WO3, WO3/Cu2O-CuO, WO3/Au and WO3/Au/Cu2O-CuO heterojunctions were sputtered on precleaned glass and Si(100) substrates. The chemical composition, crystal structure, surface morphology, optical absorption, water contact angle and photocatalytic activities of the prepared single and multilayers films were examined to elucidate the correlation between structure and other properties. SEM revealed tiny small nanoparticles for WO3 film, close-packed nanoparticles for WO3/Cu2O-CuO multilayers and nanoparticles with more open structure for WO3/Au/Cu2O-CuO heterojunctions. The WO3/Au/Cu2O-CuO heterojunctions had the highest optical absorption. The estimated band gap values were 3.16, 3.08, 2.97 and 2.65 eV for WO3, WO3/Cu2O-CuO, WO3/Au and WO3/Au/Cu2O-CuO, respectively. The WO3/Cu2O-CuO, WO3/Au and WO3/Au/Cu2O-CuO became superhydrophilic after UV illumination. The remarkable photocatalytic activities of WO3/Au/Cu2O-CuO is attributed to the enhanced efficiency of separation for photogenerated hole–electron pairs.
Numerical investigation and design optimization for enhanced efficiency of Cs2AgBiBr6 perovskite solar cell
Authors: Arif Md Zannatul , Rahman Mustafizur , Chowdhury Nayan Kumar , Islam Saral , Alam Md Ziaul , Reza Md Salim
Published: August 2024

Nowadays, environmental concerns are becoming increasingly important. As a result of the imperative to protect society, lead-free perovskites are becoming increasingly important. The lead-free compound cesium silver bismuth bromide (Cs2AgBiBr6) was numerically investigated as a potential candidate for double perovskite solar cells application. In the proposed architecture, we combine FTO/ETL-SnO2/Cs2AgBiBr6/HTL-CuI/Au, all optimized for performance. To optimize the solar cell’s performance, the device configuration was modelled using SCAPS-1D. An evaluation of the impact of various factors, including absorber thickness, defect density, electron affinity, electron and hole transport layer optimization, band diagram analysis, working temperature and quantum efficiency, was conducted. The proposed device configuration exhibited excellent photovoltaic performance, achieving a PCE of 8.15%, a Voc of 1.041 V, a Jsc of 11.79 mA cm−2, an FF of 66.41%, and a quantum efficiency of 99.19% within the visible range. This research highlights the potential of Cs2AgBiBr6 as a promising perovskite material for use in lead-free photovoltaic technology.
Theoretical study of differential cross sections for the ionization of helium by fast proton impact
Authors: Mondal M , Mandal B , Mistry T , Jana D , Purkait M
Published: August 2024

We present the angular distribution of the ejected electron for single ionization of He by fast proton impact. A four-body formalism of the three-Coulomb wave is applied to calculate the triple differential cross sections at several impact energies in the scattering, perpendicular and azimuthal planes. Moreover, the three-body formalism of three-Coulomb, two-Coulomb and first Born approximation models has also been used to study the many-body effect on electron emission and the validity of the models. In the three-Coulomb wave model, the final state wave function incorporates distortion due to the three-body mutual Coulombic interaction. In this formalism, we use an uncorrelated and correlated Born initial state, which consists of a plane wave for the incoming projectile times a two-electron bound state wavefunction of the helium atom representing the 1s2(1S) state. But, in the case of the three-body formalism, the initial state wavefunction consists of a long-range Coulomb distortion for the incoming projectile and one active electron of the He atom described by the Roothaan–Hartree–Fock wavefunction. The structure with a single or two peaks with unequal intensity is observed in the angular distributions of the triple differential cross sections for the different kinematic conditions. In addition, the influence of static electron correlations is investigated using different bound state wavefunctions for the ground state of the He target. In the four-body formalism, the present computations are very fast by reducing a nine-dimensional integral to a two-dimensional real integral. Despite the simplicity and speed of the proposed quadrature, the comparison shows that the obtained results are in reasonable agreement with the experiment and are compatible with those of other theories.
Detection of 10 to 300 keV fast neutron using CLYC, CLLB and CLLBC scintillators
Authors: Ren Feixu , Han Jifeng , Song Ruiqiang , Qian Sen , Wei Qinhua , Tang Gao , Liu Xingquan , Qu Guofeng , Zhang Junxin , Yi Chuqi , Chen Yangmei , Ren Peipei , Sun Xinyuan , Cai Hua , Ban Huiyun , Wang Zhile , Ren Jing
Published: August 2024

The neutron and gamma detection performance of multimode scintillators including Cs2LiYCl6:Ce (CLYC), Cs2LiLaBr6:Ce (CLLB) and Cs2LiLaBr6-,x
Clx:Ce (CLLBC) were tested in this work. The energy resolution for 662 keV gamma rays was 4.19% for CLLB, which was better than that of 4.80% for CLLBC and 5.27% for CLYC. The Figure of Merit value (FOM) was used to evaluate the neutron/gamma-ray (n/γ) discrimination capability, which was 2.2 for CLYC, superior than that of 1.3 for CLLBC and 1.1 for CLLB. A method for fast neutrons detection within the energy order of 100 keV was proposed, which could be realized using the 6Li(n, α)T reaction by the fact that the peak centers are sensitive to the incident neutron energy. This was validated by test the energy spectra of CLYC using an Am-Be source with various paraffin moderator, where the peak centers of the energy spectra were found to decrease linearly with the paraffin thickness. The Monte-Carlo simulation was conducted to prove the average neutron energy decreased linearly with the paraffin thickness and the energy spectra results were consistent with the experimental results. It could be concluded that 6Li enriched CLYC (CLLB or CLLBC) could be used to detect fast neutrons in the energy range of 10–300 keV, which further expand the application range of CLYC for multimode neutron gamma detection.
Simulation and analysis of the single event transient characteristics of SiGe HBT at low-temperature environment
Authors: Adekoya Mathew Adefusika , Liu Shuhuan , Wang Chao , Du Xiaozhi , Xing Tian , Wang Xuan , Li Haodi , Guo Yixian , Zhou Junye , Zhang Ximin , Wang Yutian
Published: August 2024

This study investigates the temperature dependence of single event transient (SET) effects in silicon germanium heterojunction bipolar transistors (SiGe HBTs). Using Silvaco TCAD simulations, we analyze the influence of linear energy transfer (LET), emitter bias voltage, and striking angle across a temperature range from 100 K to 300 K. The results reveal that temperature significantly affects emitter pulse current and charge collection induced by heavy ions. Higher temperatures increase charge collection, while lower temperatures correspond to higher emitter current and shorter pulse width. The study also observes an increase in bandgap energy (from 1.12 eV to 1.16 eV) and electrostatic potential (from 1.19 V to 1.25 V) with decreasing temperature. The study highlights the crucial role of temperature in SiGe HBT performance under radiation threats and emphasizes drift and diffusion mechanisms as dominant for charge collection.
Multifunctional targeting of docetaxel plus bakuchiol micelles in the treatment of invasion and metastasis of ovarian cancer
Authors: Li Qi-yan , Zhu Ri-ran , Yu Hai-ying , Liu Chun-lin , Diao Fei-yan , Jiang Ya-qi , Lin Yong-qiang , Li Xue-tao , Wang Wei-jian
Published: August 2024

The invasion and metastasis of tumors pose significant challenges in the treatment of ovarian cancer (OC), making it difficult to cure. One potential treatment approach that has gained attention is the use of matrix metalloproteinase reactive controlled release micelle preparations. In this study, we developed a novel PEG5000-PVGLIG-hyaluronic acid docetaxel/bakuchiol (PP-HA-DTX/BAK) micelles formulation with desirable characteristics such as particle size, narrow polydispersity index, and a ZETA potential of approximately −5 mV. The surface modification with HA facilitates tumor penetration into the tumor interior, while the incorporation of DSPE-PEG2000-PVGLIG-PEG5000 helps conceal DSPE-PEG2000-HA, reducing off-target effects and prolonging drug circulation time in vivo. Both in vitro and in vivo experiments demonstrated that these micelles effectively inhibit proliferation, invasion, and metastasis of OC cells while promoting apoptosis. Therefore, our findings suggest that PP-HA-DTX/BAK micelles represent a safe and effective therapeutic strategy for treating OC.
Influence of different pressure regimes on the properties of an engineered small-diameter vascular scaffold tested in a custom-made bioreactor
Authors: Ferrari Pier Francesco , De Negri Atanasio Giulia , Pralits Jan Oscar , Di Lisa Donatella , Pastorino Laura , Palombo Domenico , Perego Patrizia
Published: August 2024

Vascular tissue engineering endeavors to design, fabricate, and validate biodegradable and bioabsorbable small-diameter vascular scaffolds engineered with bioactive molecules, capable of meeting the challenges imposed by commercial vascular prostheses. A comprehensive investigation of these engineered scaffolds in bioreactor is deemed essential as a prerequisite before any in vivo experimentation in order to get information regarding their behavior under physiological conditions and predict the biological activities they will possess. This study focuses on an innovative electrospun scaffold made of poly(caprolactone) and poly(glycerol sebacate), integrating quercetin, able to modulate inflammation, and gelatin, necessary to reduce permeability. A custom-made bioreactor was used to assess the performances of the scaffolds maintained under different pressure regimes, covering the human physiological pressure range. As results, the 3D microfibrous architecture was notably influenced by the release of bioactives, maintaining the adequate properties needed for the in vivo regeneration and scaffolds showed mechanical properties similar to human native artery. Release of gelatin was adequate to avoid blood leakage and useful to make the material porous during the testing period, whereas the amount of released quercetin was useful to counteract the post-surgery inflammation. This study showcases the successful validation of an engineered scaffold in a bioreactor, enabling to consider it as a promising candidate for vascular substitutes in in vivo applications. Our approach represents a significant leap forward in the field of vascular tissue engineering, offering a multifaceted solution to the complex challenges associated with small-diameter vascular prostheses.
Incorporation of carboxymethyl chitosan (CMCS) for the modulation of physio-chemical characteristics and cell proliferation environment of the composite hydrogel microspheres
Authors: Liying Qin , Yining Yang , Yongjian Sun , Guojiang Han , Wenli Dong , Baoqin Han , Ting Su , Liming Jin , Chao Zhou , Yan Yang
Published: August 2024

Hydrogels have excellent swelling properties and have been widely applied in tissue engineering because of their similarity to the extracellular matrix (ECM). Sodium alginate (SA) and carboxymethyl chitosan (CMCS) were prepared into hydrogel microspheres with Ca2+ crosslinking in our study. The morphology, inner structure, mechanical properties, water content, swelling rate and BMP-2 loading and releasing properties were characterized. Our results showed that the composite SA /CMCS hydrogel microspheres were translucent and spherical in shape with uniform particle size. The incorporation of CMCS further increased the diameters of the microspheres, internal pore structure, water content, and mechanical properties of the SA/CMCS hydrogel microspheres. At the same SA concentration, with the increase of CMSC concentration, the diameter of microspheres could be increased by about 0.4 mm, the water content can be increased about 1%–2%. As for the mechanical properties, the compressive strength can be increased by 0.04–0.1 MPa, and the modulus of elasticity can be increased by 0.1–0.15 MPa. BMP-2 was chosen as a model agent and it could be loaded into SA/CMCS microspheres, and the incorporation of CMCS increased BMP-2 loading. The encapsulated BMP-2 was sustainably released in vitro. The leaching solutions of the SA/CMCS hydrogel microspheres exhibited good cytocompatibility and could increase ALP activity, ALP expression, and biomineralization on MC3T3-E1 cells. After 7 d of co-culture, ALP activities in S2.5C2 and S2.5C3 groups was increased by 50% and 45% compared with that of the control group. When embedded in the SA/CMCS microspheres, the MC3T3-E1 cells were evenly distributed inside the hydrogel microspheres and remained viable. Transcriptomic studies showed that incorporation of CMCS induced upregulation of 1141 differentially expressed genes (DEGs) and downregulation of 1614 DEGs compared with SA microspheres. The most significantly enriched pathways were the Wnt and MAPK signaling pathways induced by the incorporation of CMCS and BMP-2. In conclusion, our results indicated that the physiochemical characteristics of the SA hydrogel microspheres could be greatly modulated by CMCS to better mimic the ECM microenvironment and induce osteo-inductive activities of MC3T3-E1 cells.
Enhancing mechanical performance of hydroxyapatite-based bone implants via citric acid post-processing in binder jetting additive manufacturing
Authors: Huang Zhijie , Li Jiangtao , He Bing , Lu Bing , Li Yang , Zhang Rui , Lu Jingxiang , Wang Zemin , Li Xiangyou
Published: August 2024

Binder jetting is a promising technology in the additive manufacturing of bone implants, particularly for printing brittle bioceramics that are susceptible to thermal residual stresses. However, challenges in this field include low strength and undesirable size changes due to post-sintering treatments, as well as the absence of necessary organic matter like Glycosaminoglycans, citric acid (CA), etc. To address these issues, a novel approach was introduced using CA as a post-processing agent to enhance the mechanical performance of green samples and add organic matter, with boric acid (BA) as a control. A hydroxyapatite (HA) based powder mixed with 25 wt.% high-viscosity polyvinyl alcohol (PVA) was prepared and printed using a self-made printer with deionized water as the binder. The post-processing effects were analyzed in terms of mechanical properties and microstructure. The application of 5 wt.% CA solution increased the thickness of the PVA film between HA particles by 320.0%, leading to an increase in compressive strength (7.37 ± 0.28 MPa) and modulus (102.81 ± 6.74 MPa) by 840.7% and 1571.3%, respectively, achieving the mechanical standards for human trabecular bone. This work presents a simple and rapid room-temperature post-processing strategy for enhancing the mechanical properties of bone implants produced by binder jetting additive manufacturing.