bluuebunny/crossref_metadata_2025 huggingface dataset:
Identifying Elective Induction of Labor among a Diverse Pregnant Population from Electronic Health Records within a Large Integrated Health Care System
Authors: Xie Fagen , Fassett Michael J. , Im Theresa M. , Park Daniella , Chiu Vicki Y. , Getahun Darios
Published: August 2024

Objective Distinguishing between medically indicated induction of labor (iIOL) and elective induction of labor (eIOL) is a daunting process for researchers. We aimed to develop a Natural Language Processing (NLP) algorithm to identify eIOLs from electronic health records (EHRs) within a large integrated health care system.

Study Design We used structured and unstructured data from Kaiser Permanente Southern California's EHRs of patients who were <35 years old and had singleton deliveries between 37 and 40 gestational weeks. Induction of labor (IOL) pregnancies were identified if there was evidence of an IOL diagnosis code, procedure code, or documentation in a delivery flowsheet or progress note. A comprehensive NLP algorithm was developed and refined through an iterative process of chart reviews and adjudications, where IOL-associated reasons (medically indicated vs. elective induction) were reviewed. The final algorithm was applied to discern the indications of IOLs performed during the study period.

Results A total of 332,163 eligible pregnancies were identified between January 1, 2008, and December 31, 2022. Of these eligible pregnancies, 68,541 (20.6%) were IOL, of which 6,824 (10.0%) were eIOL. Validation of the NLP process against 300 randomly selected pregnancies (100 eIOL, iIOL, and non-IOL cases each) yielded a positive predictive value of 83.0% and 88.0% for eIOL and iIOL, respectively. The rates of eIOL among the maternal age groups ranged between 9.6 and 10.3%, except for the <20 years group (12.2%). Non-Hispanic White individuals had the highest rate of eIOL (13.2%), while non-Hispanic Asian/Pacific Islanders had the lowest rate of eIOL (7.8%). The rate of eIOL increased from 1.0% in the 37-week gestational age (GA) group to 20.6% in the 40-week GA group.

Conclusion Findings suggest that the developed NLP algorithm effectively identifies eIOL. It can be utilized to support eIOL-related pharmacoepidemiological studies, fill in knowledge gaps, and provide content more relevant to researchers.

Key Points
Direct Synthesis of N-Substituted Phosphinecarboxamides from [TBA][P(SiCl3)2] and Isonitriles
Authors: Wang Xi-Cun , Chen Dong-Ping , Quan Zheng-Jun , Yang Bo , Wang Xin , Chai Yao , Xu Wen-Bo , Tian Ya-Ling , Ma Yong-Jun , Alduma Anwar I. , Cao Xin-Rui
Published: August 2024

In this investigation, N-substituted phosphinecarboxamides were produced through the reaction of [TBA][P(SiCl3)2] with isonitriles. This method capitalizes on the flexibility of isonitriles as a source of both nitrogen and carbonyl groups, offering a novel route to the generation of PH2-type compounds. This approach is characterized by rapid reaction times, simple procedural requirements, compatibility with a diverse array of substrates, and the conversion of [TBA][P(SiCl3)2] into organic phosphorus compounds. Additionally, we systematically studied the reaction mechanism of isonitrile with [TBA][P(SiCl3)2] through controlled experiments and density functional theory (DFT) calculations.
Development of Liquisolid Technology to Overcome Dissolution/Absorption Limitations of Oral Drugs
Authors: Wang Huan , Zhang Xingwang
Published: August 2024

Increasing influx of poorly water-soluble drugs poses a significant challenge to oral drug delivery. Conventional solubilization techniques such as solid dispersion and cyclodextrin inclusion, while capable of improving drug dissolution, suffer from a great predicament in subsequent formulation processing. A novel “powder solution technology,” the liquisolid technique, has come to the forefront in dealing with drug solubilization and formulation of oral “problem” drugs. The liquisolid technique involves the adsorption of liquid medications onto suitable carrier and coating materials, followed by conversion into free-flowing, dry-looking, and compressible powders. In the liquisolid system, the drug is dispersed in an almost molecular state, which greatly contributes to drug dissolution and absorption. This review aims to present the fundamentals of liquisolid technology and update the concept of liquisolid processing to expand its applications. The trend of modern drug discovery, drug solubilization approaches, application of liquisolid technology in formulation innovation, formulation composition, and design of liquisolid systems were discussed in detail. Special emphasis was placed on the application of liquisolid technology to improve the dissolution and bioavailability of poorly water-soluble drugs. Accumulating evidence shows that the liquisolid technology has immense potential to improve oral delivery and facilitate the secondary development of insoluble drugs.
Genetically Predicted Iron Status Is a Causal Risk of Rheumatoid Arthritis: A Mendelian Randomization Study
Authors: Wu Boyuan
Published: August 2024

Background Current knowledge on iron's role in rheumatoid arthritis (RA) development is very limited, with studies yielding inconsistent findings. We conducted a two-sample Mendelian randomization study to assess the associations of iron status with the risk of RA.

Methods This study leveraged genetic data from a large genome-wide association study (GWAS) of 257,953 individuals to identify single nucleotide polymorphisms (SNPs) associated with iron status. We then analyzed these data in conjunction with summary-level data on RA from the IEU open GWAS project, which included 5,427 RA cases and 479,171 controls. An inverse-variance weighted method with random effects was employed, along with sensitivity analyses, to assess the relationship between iron status and RA risk.

Results Genetic predisposition to high ferritin and serum iron status was causally associated with lower odds of RA. Ferritin had an odds ratio (OR) of 0.997 (95% confidence interval [CI]: 0.995–0.997; p = 0.010), indicating that a one-unit increase in ferritin is associated with a 0.3% decrease in the odds of RA. Similarly, serum iron had an OR of 0.997 (95% CI: 0.995–0.999; p = 0.014). However, MR analyses found no significant causal associations between total iron-binding capacity (OR = 1.0, 95% CI: 0.999–1.002; p = 0.592) or transferrin saturation percentage (OR = 0.998, 95% CI: 0.996–1.000; p = 0.080) and risk of developing RA.

Conclusions This study suggests that individuals with genes linked to higher iron levels may have a lower risk of developing RA. Our findings indicate that the total amount of iron in the body, rather than how it is distributed, might be more important for RA. This raises the intriguing possibility that iron supplementation could be a preventative strategy, but further research is necessary.
High-Q WGM microcavity-based optofluidic sensor technologies for biological analysis
Authors: Wang Zhizheng , Zhou Bin , Zhang A. Ping
Published: August 2024

High-quality-factor (Q) optical microcavities have attracted extensive interest due to their unique ability to confine light for resonant circulation at the micrometer scale. Particular attention has been paid to optical whispering-gallery mode (WGM) microcavities to harness their strong light–matter interactions for biological applications. Remarkably, the combination of high-Q optical WGM microcavities with microfluidic technologies can achieve a synergistic effect in the development of high-sensitivity optofluidic sensors for many emerging biological analysis applications, such as the detection of proteins, nucleic acids, viruses, and exosomes. They can also be utilized to investigate the behavior of living cells in human organisms, which may provide new technical solutions for studies in cell biology and biophysics. In this paper, we briefly review recent progress in high-Q microcavity-based optofluidic sensor technologies and their applications in biological analysis.
Inverse resolution of spatially varying diffusion coefficient using physics-informed neural networks
Authors: Thakur Sukirt , Esmaili Ehsan , Libring Sarah , Solorio Luis , Ardekani Arezoo M.
Published: August 2024

Resolving the diffusion coefficient is a key element in many biological and engineering systems, including pharmacological drug transport and fluid mechanics analyses. Additionally, these systems often have spatial variation in the diffusion coefficient that must be determined, such as for injectable drug-eluting implants into heterogeneous tissues. Unfortunately, obtaining the diffusion coefficient from images in such cases is an inverse problem with only discrete data points. The development of a robust method that can work with such noisy and ill-posed datasets to accurately determine spatially varying diffusion coefficients is of great value across a large range of disciplines. Here, we developed an inverse solver that uses physics-informed neural networks (PINNs) to calculate spatially varying diffusion coefficients from numerical and experimental image data in varying biological and engineering applications. The residual of the transient diffusion equation for a concentration field is minimized to find the diffusion coefficient. The robustness of the method as an inverse solver was tested using both numerical and experimental datasets. The predictions show good agreement with both the numerical and experimental benchmarks; an error of less than 6.31% was obtained against all numerical benchmarks, while the diffusion coefficient calculated in experimental datasets matches the appropriate ranges of other reported literature values. Our work demonstrates the potential of using PINNs to resolve spatially varying diffusion coefficients, which may aid a wide-range of applications, such as enabling better-designed drug-eluting implants for regenerative medicine or oncology fields.
Bridging classical nucleation theory and molecular dynamics simulation for homogeneous ice nucleation
Authors: Lin Min , Xiong Zhewen , Cao Haishan
Published: August 2024

Water freezing, initiated by ice nucleation, occurs widely in nature, ranging from cellular to global phenomena. Ice nucleation has been experimentally proven to require the formation of a critical ice nucleus, consistent with classical nucleation theory (CNT). However, the accuracy of CNT quantitative predictions of critical cluster sizes and nucleation rates has never been verified experimentally. In this study, we circumvent this difficulty by using molecular dynamics (MD) simulation. The physical properties of water/ice for CNT predictions, including density, chemical potential difference, and diffusion coefficient, are independently obtained using MD simulation, whereas the calculation of interfacial free energy is based on thermodynamic assumptions of CNT, including capillarity approximation among others. The CNT predictions are compared to the MD evaluations of brute-force simulations and forward flux sampling methods. We find that the CNT and MD predicted critical cluster sizes are consistent, and the CNT predicted nucleation rates are higher than the MD predicted values within three orders of magnitude. We also find that the ice crystallized from supercooled water is stacking-disordered ice with a stacking of cubic and hexagonal ices in four representative types of stacking. The prediction discrepancies in nucleation rate mainly arise from the stacking-disordered ice structure, the asphericity of ice cluster, the uncertainty of ice–water interfacial free energy, and the kinetic attachment rate. Our study establishes a relation between CNT and MD to predict homogeneous ice nucleation.
Observation of a core-excited dipole-bound state ∼1 eV above the electron detachment threshold in cryogenically cooled acetylacetonate
Authors: Jara-Toro Rafael A. , Taccone Martín I. , Dezalay Jordan , Noble Jennifer A. , von Helden Gert , Pino Gustavo A.
Published: August 2024

Dipole-bound states in anions exist when a polar neutral core binds an electron in a diffuse orbital through charge–dipole interaction. Electronically excited polar neutral cores can also bind an electron in a diffuse orbital to form Core-Excited Dipole-Bound States (CE-DBSs), which are difficult to observe because they usually lie above the electron detachment threshold, leading to very short lifetimes and, thus, unstructured transitions. We report here the photodetachment spectroscopy of cryogenically cooled acetylacetonate anion (C5H7O2−) recorded by detecting the neutral radical produced upon photodetachment and the infrared spectroscopy in He-nanodroplets. Two DBSs were identified in this anion. One of them lies close to the electron detachment threshold (∼2.74 eV) and is associated with the ground state of the radical (D0-DBS). Surprisingly, the other DBS appears as resonant transitions at 3.69 eV and is assigned to the CE-DBS associated with the first excited state of the radical (D1-DBS). It is proposed that the resonant transitions of the D1-DBS are observed ∼1 eV above the detachment threshold because its lifetime is determined by the internal conversion to the D0-DBS, after which the fast electron detachment takes place.
Shock compression of single-crystal austenitic FeCr18Ni12.5 stainless steel to 60 GPa
Authors: Brown Nathan P. , Johnson Christopher R. , Specht Paul E.
Published: August 2024

We measured the austenitic FeCr18Ni12.5 stainless steel Hugoniot as a function of crystallographic direction to approximately 60 GPa. We shock-compressed FeCr18Ni12.5 samples oriented along ⟨100⟩, ⟨110⟩, and ⟨111⟩ to mean stresses ranging 30.5–58.1 GPa via Ta plate impact in a large-bore powder gun and measured the free-surface velocities with laser interferometry. We unambiguously observed the largest post-shock free-surface velocity along ⟨100⟩ in each experiment, which consequently produced the lowest shock velocity along that orientation. However, the propagation of experimental uncertainties through the impedance matching scheme used to compute the shock velocity produced sufficient uncertainty overlap to preclude definitive conclusion of Hugoniot anisotropy.
Sexual mixing in bisexual activity in male–male partnerships in Melbourne, Australia
Authors: Griffiths Hayden A. , Fairley Christopher K. , Ong Jason J. , Chow Eric P. F. , Phillips Tiffany R.
Published: August 2024

Background The patterns of sexually transmitted infections (STIs) in populations may be influenced by the sexual mixing within the population. We aimed to investigate the assortative sexual mixing pattern by bisexuality in male–male partnerships. Methods This was a retrospective repeated cross-sectional study of men with mostly regular male partners attending the Melbourne Sexual Health Centre between 2011 and 2019. Data on sexual practices, including their sexual practices, presence of other male/female sex partners and the gender of sexual partners in the previous 3 and 12 months, were collected using computer-assisted self-interview. We calculated the proportion of male partnerships where at least one man in the partnership reported a female sex partner. Results A total of 2056 male–male partnerships (i.e. 4112 individuals) with a median age of 29 years (IQR 25 to 35) were included. Overall, in 94.4% (1941/2056) of male–male partnerships both men had male partners only; however, in 5.5% (113/2056) of partnerships, one man had both male and female partners, and in 0.1% (2/2056) partnerships, both men had both male and female partners. No assortative relationship was found on the sexual mixing by bisexuality in male–male partnerships due to the low assortativity coefficient (r = 0.006, 95% CI: −0.004 to 0.016). Conclusion One in 20 male–male partnerships had at least one man who had both male and female partners within the preceding year. Individuals were not selective by bisexuality, suggesting that partnerships of bisexual individuals are mixed proportionately to the distribution of their characteristics. Still, these sexual mixing practices may affect STI transmission dynamics.
Limited availability of health risk communication related to community smoke exposure from prescribed burns in the United States: a review
Authors: Joe Margaux , Cocci Adrienne , Ihekweazu Chioma , Adetona Olorunfemi , Adetona Anna , Maslak Tanya , Naeher Luke P.
Published: August 2024

Prescribed burns are used to maintain wildland ecosystems and decrease fuel loads and associated wildfire hazard. Prescribed burns may produce enough smoke to cause adverse health outcomes. The aim of this review is to understand what communication materials exist for disseminating health risk information related to prescribed burn smoke and challenges to developing such communication. We examined United States peer-reviewed literature from PubMed, Scopus, and Web of Science databases and conducted an environmental scan of grey literature including materials from federal, and several US state and local governments, organisations, and newspapers. While 63% of the included peer-reviewed literature focuses on wildfire health risk communication, the review suggests similar methods and messages can be adapted for prescribed burns. The environmental scan review indicates effective strategies use several communication modes, and reliable and timely messaging. There are state regulations for prescribed burn notification, but these do not require communication or education of health risks associated with smoke exposure. Smoke management guidelines often contain information about prescribed burn health risks, but these do not discuss health risk education. Opportunities to expand effective health risk communication include improving inconsistent messaging and inter-agency collaborations, and increasing public interactions, especially with vulnerable populations.
Quantum strong cosmic censorship and black hole evaporation
Authors: Juárez-Aubry Benito A
Published: August 2024

It is common folklore that semiclassical arguments suggest that, in black hole evaporation, an initially pure state can become mixed. This is known as the information loss puzzle (or paradox). Here we argue that, if taken at face value, semiclassical gravity suggests the formation of a final singularity instead of information loss. A quantum strong cosmic censorship conjecture, for which we give a rigorous statement, supports this conclusion. Thus, there are no reasons to expect a failure of unitarity in black hole evaporation or for any quantum gravity theory that can ‘cure’ singularities.
Decoding disorder signatures of AuCl3 and vacancies in MoS2 films: from synthetic to experimental inversion
Authors: Duarte F R , Matusalem F , Grasseschi D , Rocha A R , Seixas Leandro , de Matos Christiano J S , Mukim S , Ferreira M S
Published: August 2024

This study investigates the scope of application of a recently designed inversion methodology that is capable of obtaining structural information about disordered systems through the analysis of their conductivity response signals. Here we demonstrate that inversion tools of this type are capable of sensing the presence of disorderly distributed defects and impurities even in the case where the scattering properties of the device are only weakly affected. This is done by inverting the DC conductivity response of monolayered MoS2 films containing a minute amount of AuCl3 coordinated complexes. Remarkably, we have successfully extracted detailed information about the concentration of AuCl3 by decoding its signatures on the transport features of simulated devices. In addition to the case of theoretically generated Hamiltonians, we have also carried out a full inversion procedure from experimentally measured signals of similar structures. Based on experimental input signals of MoS2 with naturally occurring vacancies, we were able to quantify the vacancy concentration contained in the samples, which indicates that the inversion methodology has experimental applicability as long as the input signal is able to resolve the characteristic contributions of the type of disorder in question. Being able to handle more complex, realistic scenarios unlocks the method’s applicability for designing and engineering even more elaborate materials.
Correlating Cu dopant concentration, optoelectronic properties, and photocatalytic activity of ZnO nanostructures: experimental and theoretical insights
Authors: Esbergenova Amugul , Hojamberdiev Mirabbos , Mamatkulov Shavkat , Jalolov Rivojiddin , Kong Debin , Ruzimuradov Olim , Shaislamov Ulugbek
Published: August 2024

The photocatalytic activity of photocatalysts can be enhanced by cation doping, and the dopant concentration plays a key role in achieving high efficiency. This study explores the impact of copper (Cu) doping at concentrations ranging from 0% to 10% on the microstructural, optical, electronic, and photocatalytic properties of zinc oxide (ZnO) nanostructures. The x-ray diffraction analysis shows a non-linear alteration in the lattice parameters with increasing the Cu content and the formation of CuO as a secondary phase at the Cu concentration of >3%. Density functional theory calculations provide insights into the change in the electronic structures of ZnO induced by Cu doping, leading to the formation of localized d electronic levels above the valence band maximum. The modulation of the electronic structure of ZnO by Cu doping facilitates the visible light absorption via O 2p → Cu 3d and Cu 3d → Zn 2p transitions. Photoluminescence spectroscopy reveals a quenching of the defect-related emission peak at approximately 570 nm for all Cu-doped ZnO nanostructures, indicating a reduction in the structural and other defects. The photocatalytic activity tests confirm that the ZnO nanostructures doped with 3% Cu exhibit the highest efficiency compared to other samples due to the suitable band-edge position and visible light absorption.
Continuous gated first-passage processes
Authors: Scher Yuval , Kumar Aanjaneya , Santhanam M S , Reuveni Shlomi
Published: August 2024

Gated first-passage processes, where completion depends on both hitting a target and satisfying additional constraints, are prevalent across various fields. Despite their significance, analytical solutions to basic problems remain unknown, e.g. the detection time of a diffusing particle by a gated interval, disk, or sphere. In this paper, we elucidate the challenges posed by continuous gated first-passage processes and present a renewal framework to overcome them. This framework offers a unified approach for a wide range of problems, including those with single-point, half-line, and interval targets. The latter have so far evaded exact solutions. Our analysis reveals that solutions to gated problems can be obtained directly from the ungated dynamics. This, in turn, reveals universal properties and asymptotic behaviors, shedding light on cryptic intermediate-time regimes and refining the notion of high-crypticity for continuous-space gated processes. Moreover, we extend our formalism to higher dimensions, showcasing its versatility and applicability. Overall, this work provides valuable insights into the dynamics of continuous gated first-passage processes and offers analytical tools for studying them across diverse domains.
Stable implicit numerical algorithm of time-dependent Ginzburg–Landau theory coupled with thermal effect for vortex behaviors in hybrid superconductor systems
Authors: Wang Qing-Yu , Xue Cun
Published: August 2024

Hybrid multi-superconducting structures exist in a variety of superconducting devices, such as superconductor–insulator–superconductor multilayer structure in superconducting radio-frequency cavities, bilayer structures in superconducting electronic devices, and superconducting wires. Investigating the vortex dynamics at microscopic scale is crucial for applications of hybrid superconducting structures.The time-dependent Ginzburg–Landau (TDGL) theory is a powerful tool for describing the vortex dynamics in superconductors through the order parameter

ψ

and vector potential A. However, the difference in order parameter

ψ

, coherence length

ξ

, and GL parameters

κ

among the components of hybrid systems will bring significant challenges to numerical simulation of TDGL equations. Meanwhile, the energy dissipation associated with vortex motion necessitates considering the thermal effects on vortex dynamics. In this paper, we introduce an efficient, stable, and parallel implicit finite-difference algorithm, implemented on GPU, for coupling the TDGL and thermal diffusion equations for hybrid structures. Linearization of nonlinear source terms is applied to TDGL-II to enhance the stability of algorithm. The iterative Jacobi method is applied to the generalized TDGL-I. Alternating direction implicit methods combined with tridiagonal matrix method or CTDMA are used to solve TDGL-II and heat diffusion equations with different boundary conditions. This algorithm enables us to explore the vortex dynamics with associated thermal effects of mesoscopic large hybrid multi-superconducting structures within reasonable amounts of computational time. Our approach aids in revealing and understanding the underlying physical mechanisms behind the collective response of vortices, and contributes to the mastery, adjustment, and optimization of superconductivities in hybrid structures.
Fate of localization features in a one-dimensional non-Hermitian flat-band lattice with quasiperiodic modulations
Authors: Liu Hui , Lu Zhanpeng , Xia Xu , Xu Zhihao
Published: August 2024

We investigate the influence of quasiperiodic modulations on one-dimensional non-Hermitian diamond lattices with an artificial magnetic flux θ that possess flat bands. Our study shows that the symmetry of these modulations and the magnetic flux θ play a pivotal role in shaping the localization properties of the system. When θ = 0, the non-Hermitian lattice exhibits a single flat band in the crystalline case, and symmetric as well as antisymmetric modulations can induce accurate mobility edges. In contrast, when

θ
=
π

, the clean diamond lattice manifests three dispersionless bands referred to as an ‘all-band-flat’ (ABF) structure, irrespective of the non-Hermitian parameter. The ABF structure restricts the transition from delocalized to localized states, as all states remain localized for any finite symmetric modulation. Our numerical calculations further unveil that the ABF system subjected to antisymmetric modulations exhibits multifractal-to-localized edges. Multifractal states are predominantly concentrated in the internal region of the spectrum. Additionally, we explore the case where θ lies within the range of

(
0
,
π
)

, revealing a diverse array of complex localization features. Finally, we propose a classical electrical circuit scheme to realize the non-Hermitian flat-band chain with quasiperiodic modulations.
Radioxenon beta-gamma coincidence efficiency for a SAUNA detector by Geant4 simulation
Authors: Zahran I , Ababneh E , Okoor S , Albqoor A
Published: August 2024

A simulation for SAUNA II detector was carried out using the GEANT4 platform. The results demonstrated the accuracy of the simulation, which was well consistent with the experimental results. The simulation was used to calculate the coincidence detection efficiency of each radioxenon isotope, as well as to calculate the resolution for conversion electron peaks. Furthermore, using a 137Cs point source, the simulation was also utilized to perform the beta detector calibration procedure in two scenarios: first, the 137Cs was placed close to the middle of the plastic scintillator, and second, the 137Cs was placed outside the NaI(Tl) detector. The results showed that the spectrum in the first case is better; the source is closer to the plastic detector, leading to maximum Compton scattering. In the second case, a line in the spectrum disappears, so a high-intensity source is needed. Several methods exist to determine the coincidence detection efficiency of the detector. The recommended approach is to determine the total detection efficiency for different regions of interest. The simulation was also used to investigate the effect of replacing helium with nitrogen as a xenon-carrier gas, with the nitrogen resulting in a slight improvement in coincidence detection efficiencies and conversion electron resolution.
Polarization converter integrated millimeter wave MIMO antenna for dual CP generation
Authors: Das Priyanka , Kundu Surajit
Published: August 2024

This article provides a novel technique of generating both RHCP and LHCP waves from a CPW fed MIMO antenna over a wide frequency range 24.6–28.2 GHz by integrating it with a metasurface. The metasurface is designed as a broadband reflective cross-polarization converter working from 23–32.6 GHz. The metasurface is placed 1 mm below the MIMO antenna constituting orthogonally placed antenna elements. The impinging electromagnetic waves from the linearly polarized antenna are converted into circularly polarized waves when they get reflected from the metasurface and interfere with the radiated waves from the antenna. In order to decipher the underlying modal behaviours of the metasurface, characteristic mode analysis is utilized. Due to orthogonal orientation of the antennas, oppositely placed antennas exhibit the same type of polarization conversion while adjacently placed antennas exhibit opposite type of polarization conversion. This results in generation of both RHCP and LHCP waves from different elements of the MIMO antenna using the same metasurface at 5 G frequencies registering an axial ratio bandwidth (ARBW) of 15.3%. With a diversity gain (DG) of better than 9.96 and an envelope correlation coefficient (CC) of less than 0.015, the proposed CP antenna exhibits strong MIMO performance. Prototypes of the antenna and the metasurface have been fabricated and measured for validating the simulated results.
Efficiently shape-selective synthesis of single crystal silver nanocube with the combination of HNO3/NaCl and reaction time for developing surface enhanced Raman scattering (SERS) substrate
Authors: Do Phuong−Thao , Vo Khuong Quoc
Published: August 2024

Shape control of noble nanomaterials has garnered significant attention in the past decade because niche applications rely on the relationship between the nanoparticle morphology and optical properties. Although many chemical methods have been reported, there is still a need for improvement in terms of uniformity, yields, and synthesis scale. This work exploited the novel modification approach based on the polyol method to control synthesis to obtain a high amount of single-crystal silver nanocubes (AgNCs) with relatively homogeneous sizes and edge lengths of approximately 100 nm. Furthermore, we have discovered the high effectiveness of controlling temperature conditions to examine the conversion from silver nanocubes to tetrahedron nanoparticles, which had been rarely studied before. These as-prepared AgNCs colloidal solutions were further used to develop the SERS substrate on the glass slide through the facile drop cast method. Additionally, through synthesis using ethylene glycol and redispersed in the ethanol solvent, the obtained AgNCs have a high probability coverage on the glass slide once natural evaporation technique to achieve a remarkable amplification effect and reproducibility behavior. It was explored that these substrates could significantly enhance the Raman signal of 4-mercaptobenzoic acid (4-MBA), which is utilized as the probe molecule to assess the SERS behaviors. The enhancement factor (EF) of the SERS substrates prepared using AgNCs was approximately 3.6 × 106. The presence of 4-MBA could be detected with AgNCs in concentrations ranging from 0.01 to 10 mM, with a limit of detection (LOD) of 8.40 μM and a limit of quantification (LOQ) of 25.46 μM. Through analyzing over 20 different spots on various AgNC substrates, synthesized with similar methods and conditions, the Raman signals of 4-MBA were almost unchanged, with a relative standard deviation (RSD) value of 5.81%, indicating that the SERS signal produced by AgNC substrates was highly reproducible. Based on the results, the SERS nanosubstrates developed with AgNCs could potentially be used to detect trace amounts of other harmful organic compounds.
Even- and odd-parity stabilities of black holes in Einstein-Aether gravity
Authors: Felice Antonio De , Mukohyama Shinji , Tsujikawa Shinji , Wang Anzhong , Zhang Chao
Published: August 2024

In Einstein-Aether theories with a timelike unit vector field, we study the linear stability of static and spherically symmetric black holes against both even- and odd-parity perturbations.
For this purpose, we formulate a gauge-invariant black hole perturbation theory in the background Aether-orthogonal frame where the spacelike property of hypersurfaces orthogonal to the timelike Aether field is always maintained even inside the metric horizon. Using a short-wavelength approximation with large radial and angular momenta, we show that, in general, there are three dynamical degrees
of freedom arising from the even-parity sector besides two propagating degrees of freedom present in the odd-parity sector. The propagation speeds of even-parity perturbations and their no-ghost conditions coincide with those of tensor, vector, and scalar perturbations on the Minkowski background, while the odd sector contains tensor and vector modes with the same propagation speeds as those in the even-parity sector (and hence as those on the Minkowski background).
Thus, the consistent study of black hole perturbations in the Aether-orthogonal frame on static and spherically symmetric backgrounds does not add new small-scale stability conditions to those known for the Minkowski background in the literature.
High redshift LBGs from deep broadband imaging for future spectroscopic surveys
Authors: Ruhlmann-Kleider Vanina , Yèche Christophe , Magneville Christophe , Coquinot Henri , Armengaud Eric , Palanque-Delabrouille Nathalie , Raichoor Anand , Aguilar Jessica Nicole , Ahlen Steven , Arnouts Stéphane , Brooks David , Chaussidon Edmond , Claybaugh Todd , Dawson Kyle , de la Macorra Axel , Dey Arjun , Dey Biprateep , Doel Peter , Fanning Kevin , Ferraro Simone , Forero-Romero Jaime E. , Gontcho A Gontcho Satya , Gutierrez Gaston , Gwyn Stephen , Honscheid Klaus , Juneau Stephanie , Kehoe Robert , Kisner Theodore , Kremin Anthony , Lambert Andrew , Landriau Martin , Le Guillou Laurent , Levi Michael E. , Manera Marc , Martini Paul , Meisner Aaron , Miquel Ramon , Moustakas John , Mueller Eva-Maria , Muñoz-Gutiérrez Andrea , Newman Jeffrey A. , Nie Jundan , Niz Gustavo , Payerne Constantin , Picouet Vincent , Ravoux Corentin , Rezaie Mehdi , Rossi Graziano , Sanchez Eusebio , Sawicki Marcin , Schlafly Edward F. , Schlegel David , Schubnell Michael , Seo Hee-Jong , Silber Joseph , Sprayberry David , Taran Julien , Tarlé Gregory , Weaver Benjamin A. , White Martin , Wilson Michael J. , Zhou Zhimin , Zou Hu
Published: August 2024

Lyman break galaxies (LBGs) are promising probes for clustering measurements at high redshift, z > 2, a region only covered so far by Lyman-α forest measurements. In this paper, we investigate the feasibility of selecting LBGs
by exploiting the existence of a strong deficit of flux shortward of the Lyman limit, due to various absorption processes along the line of sight. The target selection relies on deep imaging data from the HSC and CLAUDS surveys in the g, r, z and u bands, respectively, with median depths reaching 27 AB in all bands.
The selections were validated by several dedicated spectroscopic observation campaigns with DESI. Visual inspection of spectra has enabled us to develop an automated spectroscopic typing and redshift estimation algorithm specific to LBGs. Based on these data and tools, we assess the efficiency and purity of target selections optimised for different purposes.
Selections providing a wide redshift coverage
retain 57% of the observed targets after spectroscopic confirmation with DESI, and provide an efficiency for LBGs of 83±3%, for a purity of the selected LBG sample of 90±2%. This would deliver a confirmed LBG density of ~ 620 deg-2 in the range 2.3 < z < 3.5 for a r-band limiting magnitude r < 24.2.
Selections optimised for high redshift efficiency
retain 73% of the observed targets after spectroscopic confirmation, with 89±4% efficiency for 97±2% purity. This would provide a confirmed LBG density of ~ 470 deg-2 in the range 2.8 < z < 3.5 for a r-band limiting magnitude r < 24.5.
A preliminary study of the LBG sample 3d-clustering properties is also presented and used to estimate the LBG linear bias. A value of b
LBG = 3.3 ± 0.2  (stat.) is obtained for a mean redshift of 2.9 and a limiting magnitude in r of 24.2, in agreement with results reported in the literature.
On the wormhole-warp drive correspondence
Authors: Garattini Remo , Zatrimaylov Kirill
Published: August 2024

We propose a correspondence between the Morris-Thorne wormhole metric and a warp drive metric, which generalizes an earlier result by H. Ellis regarding the Schwarzschild black hole metric and makes it possible to embed a warp drive in a wormhole background. We demonstrate that in order to do that, one needs to also generalize the Natario-Alcubierre definition of warp drive and introduce nonzero intrinsic curvature. Surprisingly, we find out that Alcubierre warp drives cannot traverse Morris-Thorne wormholes; nonetheless, this “no-go” theorem does not extend to spherically symmetric warp drives that are not localized in space.
Enhanced power spectra from multi-field inflation
Authors: Christodoulidis Perseas , Gong Jinn-Ouk
Published: August 2024

We investigate the enhancement of the power spectra large
enough to produce primordial black holes in models with multiple scalar fields.
We present analytic solutions for the perturbations in the case of constant turns without the need for an effective field theory for the first time and clarify the role of the Hubble friction that has been overlooked previously.
We derive the criteria for an arbitrary number of fields that can lead to an exponential amplification of the curvature perturbation on subhorizon scales, while leaving the perturbations stable on superhorizon scales. Finally, we apply our results to a three-field generalization of the “ultra-light” scenario and show how the presence of field-space torsion can yield distinct observables compared to the two-field case.
Investigation of the radial profile of galactic magnetic fields using rotation measure of background quasars
Authors: Burman Shivam , Sharma Paras , Malik Sunil , Singh Suprit
Published: August 2024

Probing magnetic fields in high-redshift galactic systems is crucial to investigate galactic dynamics and evolution. Utilizing the rotation measure of the background quasars, we have developed a radial profile of the magnetic field in a typical high-z galaxy. We have compiled a catalog of 59 confirmed quasar sightlines, having one intervening Mg II absorber in the redshift range 0.372 ≤ z
abs ≤ 0.8. The presence of the foreground galaxy is ensured by comparing the photometric and spectroscopic redshifts within 3σ
z-photo and visual checks. These quasar line-of-sights (LoS) pass through various impact parameters (D) up to 160 kpc, covering the circumgalactic medium of a typical Milky-Way type galaxy. Utilizing the residual rotation measure (RRM) of these sightlines, we estimated the excess in RRM dispersion, σ
ex
RRM. We found σ
ex
RRM decreases with increasing D. We translated σ
ex
RRM to average LoS magnetic field strength, 〈 B
∥ 〉 by considering a typical electron column density. Consequently, the decreasing trend is sustained in the magnetic field. In particular for sightlines with D ≤ 50 kpc and D> 50 kpc, 〈 B
∥ 〉 is found to be 2.39 ± 0.7 μG and 1.67 ± 0.38 μG, respectively. This suggests a clear indication of varying magnetic field from the disk to the circumgalactic medium. This work provides a methodology that, when applied to ongoing and future radio polarisation surveys such as LOFAR and SKA, promises to significantly enhance our understanding of magnetic field mapping in galactic systems.
Strain tunable excitonic optical properties in monolayer Ga2O3
Authors: Cui 崔 Hao-Lei 浩磊 , Quan 权 Zhen 真 , Wang 王 Shu-Dong 舒东
Published: August 2024

Two-dimensional (2D) Ga2O3 has been confirmed to be a stable structure with five atomic layer thickness configuration. In this work, we study the quasi-particle electronic band structures and then access the excitonic optical properties through solving the Bethe–Salpeter equation (BSE). The results reveal that the exciton dominates the optical absorption in the visible light region with the binding energy as large as ∼ 1.0 eV, which is highly stable at room temperature. Importantly, both the dominant absorption P1 and P2 peaks are optically bright without dark exciton between them, and thus is favorable for luminescence process. The calculated radiative lifetime of the lowest-energy exciton is 2.0×10−11 s at 0 K. Furthermore, the radiative lifetime under +4% tensile strain is one order of magnitude shorter than that of the strain-free case, while it is less insensitive under the compressive strain. Our findings set the stage for future theoretical and experimental investigation on monolayer Ga2O3.
A comparative study of crystal geometry, material, and reconstruction algorithms on MicroPET scanner performance
Authors: Sadremomtaz Alireza , Taherparvar Payvand , Saber Mohaddeseh
Published: August 2024

Small-animal PET, also known as microPET, has been developed
to enhance image quality by improving spatial resolution and
sensitivity due to its smaller ring and crystal size. However, the
reduction of crystal size and the presence of gaps between cuboidal
crystals could reduce sensitivity. MicroPET with tapered arrays has
been developed to simultaneously improve sensitivity and spatial
resolution. This study compared the performance of 14 × 14
and 28 × 28 array microPETs using LSO and CZT crystal
materials. The impact of crystal design and reconstruction
algorithms on image quality and performance parameters was
investigated, using GATE Monte Carlo simulation toolkit. The
findings showed that sensitivity increased with crystal thickness,
particularly in LSO. The 14 × 14 arrays consistently
exhibited higher sensitivity, while the 28 × 28 arrays had
superior spatial resolution. NECR values increased with crystal
thickness, with LSO outperforming CZT. Scatter and random fractions
were low. Different reconstruction algorithms had negligible effects
on FWHM and CNR but influenced SNR, with the COSEM algorithm
achieving significantly reduced noise. The small size of crystals
and tapered arrays contributed to improved sensitivity and spatial
resolution. However, there was a trade-off between sensitivity and
spatial resolution. LSO crystals showed better performance, but the
choice between array sizes depended on specific imaging
requirements. This study provides insights into optimizing microPET
design for enhanced imaging capabilities.
Glycerol-blended chitosan membranes with directional micro-grooves and reduced stiffness improve Schwann cell wound healing
Authors: Scaccini L , Battisti A , Convertino D , Puppi D , Gagliardi M , Cecchini M , Tonazzini I
Published: August 2024

Regenerative medicine is continuously looking for new natural, biocompatible and possibly biodegradable materials, but also mechanically compliant. Chitosan is emerging as a promising FDA-approved biopolymer for tissue engineering, however, its exploitation in regenerative devices is limited by its brittleness and can be further improved, for example by blending it with other materials or by tuning its superficial microstructure. Here, we developed membranes made of chitosan (Chi) and glycerol, by solvent casting, and micro-patterned them with directional geometries having different levels of axial symmetry. These membranes were characterized by light microscopies, atomic force microscopy (AFM), by thermal, mechanical and degradation assays, and also tested in vitro as scaffolds with Schwann cells (SCs). The glycerol-blended Chi membranes are optimized in terms of mechanical properties, and present a physiological-grade Young’s modulus (≈0.7 MPa). The directional topographies are effective in directing cell polarization and migration and in particular are highly performant substrates for collective cell migration. Here, we demonstrate that a combination of a soft compliant biomaterial and a topographical micropatterning can improve the integration of these scaffolds with SCs, a fundamental step in the peripheral nerve regeneration process.
Assessment of artificial bone materials with different structural pore sizes obtained from 3D printed polycaprolactone/β-tricalcium phosphate (3D PCL/β-TCP)
Authors: Qianjuan Zhao , Rong Shan , Shengxi Liu , Xuanhao Liu , Bin Liu , Fuxiang Song
Published: August 2024

Artificial bone is the alternative candidate for the bone defect treatment under the circumstance that there exits enormous challenge to remedy the bone defect caused by attributes like trauma and tumors. However, the impact of pore size discrepancy for regulating new bone generation is still ambiguous. Using direct 3D printing technology, customized 3D polycaprolactone/β-tricalcium phosphate (PCL/β-TCP) artificial bones with different structural pore sizes (1.8, 2.0, 2.3, 2.5, and 2.8 mm) were successfully prepared, abbreviated as the 3D PCL/β-TCP. 3D PCL/β-TCP exhibited a 3D porous structure morphology similar to natural bone and possessed outstanding mechanical properties. Computational fluid dynamics analysis indicated that as the structural pore size increased from 1.8 to 2.8 mm, both velocity difference (from 4.64 × 10−5 to 7.23 × 10−6 m s−1) and depressurization (from 7.17 × 10−2 to 2.25 × 10−2 Pa) decreased as the medium passed through. In vitro biomimetic mineralization experiments confirmed that 3D PCL/β-TCP artificial bones could induce calcium–phosphate complex generation within 4 weeks. Moreover, CCK-8 and Calcein AM live cell staining experiments demonstrated that 3D PCL/β-TCP artificial bones with different structural pore sizes exhibited advantageous cell compatibility, promoting MC3T3-E1 cell proliferation and adhesion. In vivo experiments in rats further indicated that 3D PCL/β-TCP artificial bones with different structural pore sizes promoted new bone formation, with the 2.5 mm group showing the most significant effect. In conclusion, 3D PCL/β-TCP artificial bone with different structural pore sizes could promote new bone formation and 2.5 mm group was the recommended for the bone defect repair.
Effect of permafrost degradation on grassland net primary productivity in Qinghai–Tibet Plateau
Authors: Hu Jianan , Nan Zhuotong , Ji Hailong , Zhao Shuping , Ou Minyue
Published: August 2024

Climate warming poses complex challenges for alpine ecosystems on the Qinghai–Tibetan Plateau (QTP), further exacerbated by permafrost degradation. Quantifying the specific ecological impacts of permafrost thaw remains elusive, as ecological variations are also influenced by external climate factors. This study tackles this gap by employing the Noah-MP model to simultaneously simulate permafrost thermal–hydrological dynamics and net primary production (NPP) across the Three River Headwaters Region from 1989 to 2018. Model results were validated against observations. To isolate the ecological effects of permafrost thaw, we implemented a novel relative time transformation on the simulation results. Our analysis reveals a 7.5 × 104 km2 reduction in permafrost coverage during the study period, coinciding with a 1.09 g C m−2 yr−2 increase in NPP. While precipitation is the primary driver of NPP changes in most years, soil moisture emerges as a crucial factor during permafrost disappearance, when the ground transitions to seasonally frozen ground. Surprisingly, the NPP response to permafrost disappearance exhibited a transient effect, diminishing to negligible levels within five years post-thaw. These findings enhance our understanding of the intricate and dynamic responses of the QTP ecosystem to permafrost degradation under a warming climate.