bluuebunny/crossref_metadata_2025 huggingface dataset:
A broadband circularly polarized Fabry Perot antenna with spatially separated superstrate area excitation for CubeSat applications
Authors: De Ratul , Abegaonkar Mahesh P. , Basu Ananjan
Published: July 2023

This article describes the development of a high-gain, broadband, circularly polarized Fabry–Perot cavity (FPC) antenna for high-data-rate communication in CubeSat/SmallSat applications. In this work, the concept of spatially separated superstrate area excitation is developed for the first time in FPC antennas. This concept is then validated and applied to increase the gain and the axial ratio bandwidth of a conventional narrowband circularly polarized source patch antenna. The antenna’s design leverages independent control of polarization at different frequencies, resulting in a large overall bandwidth. The fabricated prototype antenna provides right hand circular polarization with a peak measured gain of 15.73 dBic over a common bandwidth of 1.03 GHz ranging from 7.99 GHz to 9.02 GHz. The gain variation over the bandwidth is less than 1.3 dBic. The antenna measures 80 mm × 80 mm × 21.14 mm and is simple, lightweight, easily integrable with CubeSat body, and useful for X-Band data downlink. When integrated with the metallic body of a 1U CubeSat, the simulated gain of the antenna increases to 17.23 dBic, with a peak measured gain of 16.83 dBic. A deployment method is proposed for this antenna that results in a total stowed volume of only 2.13λo × 2.13λo × 0.084λo (0.38 $${\lambda }_{o}^{3}$$

λ

o

3

).
Detection of left ventricular systolic dysfunction from single-lead electrocardiography adapted for portable and wearable devices
Authors: Khunte Akshay , Sangha Veer , Oikonomou Evangelos K. , Dhingra Lovedeep S. , Aminorroaya Arya , Mortazavi Bobak J. , Coppi Andreas , Brandt Cynthia A. , Krumholz Harlan M. , Khera Rohan
Published: July 2023

Artificial intelligence (AI) can detect left ventricular systolic dysfunction (LVSD) from electrocardiograms (ECGs). Wearable devices could allow for broad AI-based screening but frequently obtain noisy ECGs. We report a novel strategy that automates the detection of hidden cardiovascular diseases, such as LVSD, adapted for noisy single-lead ECGs obtained on wearable and portable devices. We use 385,601 ECGs for development of a standard and noise-adapted model. For the noise-adapted model, ECGs are augmented during training with random gaussian noise within four distinct frequency ranges, each emulating real-world noise sources. Both models perform comparably on standard ECGs with an AUROC of 0.90. The noise-adapted model performs significantly better on the same test set augmented with four distinct real-world noise recordings at multiple signal-to-noise ratios (SNRs), including noise isolated from a portable device ECG. The standard and noise-adapted models have an AUROC of 0.72 and 0.87, respectively, when evaluated on ECGs augmented with portable ECG device noise at an SNR of 0.5. This approach represents a novel strategy for the development of wearable-adapted tools from clinical ECG repositories.
Shark teeth zinc isotope values document intrapopulation foraging differences related to ontogeny and sex
Authors: McCormack Jeremy , Karnes Molly , Haulsee Danielle , Fox Dewayne , Kim Sora L.
Published: July 2023

Trophic ecology and resource use are challenging to discern in migratory marine species, including sharks. However, effective management and conservation strategies depend on understanding these life history details. Here we investigate whether dental enameloid zinc isotope (δ66Znen) values can be used to infer intrapopulation differences in foraging ecology by comparing δ66Znenwith same-tooth collagen carbon and nitrogen (δ13Ccoll, δ15Ncoll) values from critically endangered sand tiger sharks (Carcharias taurus) from Delaware Bay (USA). We document ontogeny and sex-related isotopic differences indicating distinct diet and habitat use at the time of tooth formation. Adult females have the most distinct isotopic niche, likely feeding on higher trophic level prey in a distinct habitat. This multi-proxy approach characterises an animal’s isotopic niche in greater detail than traditional isotope analysis alone and shows that δ66Znenanalysis can highlight intrapopulation dietary variability thereby informing conservation management and, due to good δ66Znenfossil tooth preservation, palaeoecological reconstructions.
Correlated flat bands and quantum spin liquid state in a cluster Mott insulator
Authors: Hu Jiayu , Zhang Xuefeng , Hu Cong , Sun Jian , Wang Xiaoqun , Lin Hai-Qing , Li Gang
Published: July 2023

Flat bands are rare in pristine solids and are unstable against electronic correlations or other types of long-range order. Unlike atomic-scale Hubbard systems or Moiré materials, where electronic correlations are either localized or long-ranged, pristine flat band systems with short-range interactions that do not break symmetry spontaneously are less known and intriguing. These systems could bridge the gap between atomic Mott insulators and Moiré correlated insulators, offering a unique platform to explore their mysterious relation. Using an analytical analysis, further verified by numerical calculations, we show that monolayer Nb3Cl8 is a unique flat band system with short-range interactions. We present clear evidence that it is a cluster Mott insulator, which nicely explains the electronic structure observed in angle-resolved photoemission spectroscopy. We further propose that monolayer Nb3Cl8 may constitute a rare example of molecular quantum spin liquid with flat bands.
Advanced spectroscopic techniques for characterizing defects in perovskite solar cells
Authors: Srivastava Saurabh , Ranjan Sudhir , Yadav Lokesh , Sharma Tejasvini , Choudhary Shivani , Agarwal Daksh , Singh Anand , Satapathi Soumitra , Gupta Raju Kumar , Garg Ashish , Nalwa Kanwar S.
Published: July 2023

There is currently substantial interest in commercializing perovskite solar cells as they offer superior properties over silicon-based solar cells, such as ability for bandgap tuning, higher absorption coefficients, and potentially lower manufacturing costs. However, trap states originating from ionic vacancies, imperfect interfaces, and grain boundaries have hampered their performance and long-term stability during operation. Identifying and quantifying defects in perovskite solar cells becomes inevitable to address these challenges and mitigate the deteriorating effects of these defects. This Review focuses on recent developments in optical and electrical characterization techniques employed for the investigation of defects in halide perovskites and the techniques to understand ion migration in devices. We focus on sample preparation, advantages, limitations, and the nature of information obtained from each of the spectroscopic techniques. This Review will enable the researchers to understand and identify suitable characterization techniques for characterizing defect concentrations and their energetic and spatial distribution in perovskite solar cells.
Fire may prevent future Amazon forest recovery after large-scale deforestation
Authors: Drüke Markus , Sakschewski Boris , von Bloh Werner , Billing Maik , Lucht Wolfgang , Thonicke Kirsten
Published: July 2023

The Amazon forest is regarded as a tipping element of the Earth system, susceptible to a regime change from tropical forest to savanna and grassland due to anthropogenic land use and climate change. Previous research highlighted the role of fire in amplifying irreversible large-scale Amazon die-back. However, large-scale feedback analyses which integrate the interplay of fire with climate and land-use change are currently lacking. To address this gap, here we applied the fire-enabled Potsdam Earth Model to examine these feedback mechanisms in the Amazon. By studying forest recovery after complete deforestation, we discovered that fire prevents regrowth across 56-82% of the potential natural forest area, contingent on atmospheric carbon dioxide levels. This emphasizes the significant contribution of fire to the irreversible transition, effectively locking the Amazon into a stable grassland state. Introducing fire dynamics into future assessments is vital for understanding climate and land-use impacts in the region.
The silent impact of underground climate change on civil infrastructure
Authors: Rotta Loria Alessandro F.
Published: July 2023

Urban areas increasingly suffer from subsurface heat islands: an underground climate change responsible for environmental, public health, and transportation issues. Soils, rocks, and construction materials deform under the influence of temperature variations and excessive deformations can affect the performance of civil infrastructure. Here I explore if ground deformations caused by subsurface heat islands might affect civil infrastructure. The Chicago Loop district is used as a case study. A 3-D computer model informed by data collected via a network of temperature sensors is used to characterize the ground temperature variations, deformations, and displacements caused by underground climate change. These deformations and displacements are significant and, on a case-by-case basis, may be incompatible with the operational requirements of civil structures. Therefore, the impact of underground climate change on civil infrastructure should be considered in future urban planning strategies to avoid possible structural damage and malfunction. Overall, this work suggests that underground climate change can represent a silent hazard for civil infrastructure in the Chicago Loop and other urban areas worldwide, but also an opportunity to reutilize or minimize waste heat in the ground.
Climate change to drive increasing overlap between Pacific tuna fisheries and emerging deep-sea mining industry
Authors: Amon Diva J. , Palacios-Abrantes Juliano , Drazen Jeffrey C. , Lily Hannah , Nathan Neil , van der Grient Jesse M. A. , McCauley Douglas
Published: July 2023

In ocean areas beyond national jurisdiction, various legal regimes and governance structures result in diffused responsibility and create challenges for management. Here we show those challenges are set to expand with climate change driving increasing overlap between eastern Pacific tuna fisheries and the emerging industry of deep-sea mining. Climate models suggest that tuna distributions will shift in the coming decades. Within the Clarion-Clipperton Zone of the Pacific Ocean, a region containing 1.1 million km2 of deep-sea mining exploration contracts, the total biomass for bigeye, skipjack, and yellowfin tuna species are forecasted to increase relative to today under two tested climate-change scenarios. Percentage increases are 10–11% for bigeye, 30–31% for skipjack, and 23% for yellowfin. The interactions between mining, fish populations, and climate change are complex and unknown. However, these projected increases in overlap indicate that the potential for conflict and resultant environmental and economic repercussions will be exacerbated in a climate-altered ocean. This has implications for the holistic and sustainable management of this area, with pathways suggested for closing these critical gaps.
Free and enclosed inertial active gas
Authors: Sandoval Mario
Published: July 2023

In this work, an inertial active gas in three dimensions made of spherical non-interactive active Brownian particles with both translational and rotational inertia (IABPs) is studied, in both a free and an enclosed scenario.
Development of nanozymes for promising alleviation of COVID-19-associated arthritis
Authors: Li Dan , Zhao Baofeng , Zhuang Pengfei , Mei Xifan
Published: July 2023

Nanozymes, with functions such as virus disinfection, oxidative stress reduction, cytokine production regulation, and inflammation reduction, may be a promising treatment for COVID-19-related arthritis linked to shared factors.
Engineering a platelet-rich plasma-based multifunctional injectable hydrogel with photothermal, antibacterial, and antioxidant properties for skin regeneration
Authors: Alinezhad Vajihe , Esmaeilzadeh Kimia , Bagheri Hadi , Zeighami Habib , Kalantari-Hesari Ali , Jafari Rahim , Makvandi Pooyan , Xu Yi , Mohammadi Hamidreza , Shahbazi Mohammad-Ali , Maleki Aziz
Published: July 2023

This study presents a novel photothermally active hydrogel that contains platelet-rich plasma for infected wound healing. The hydrogel showed antibacterial, antioxidant, and hemostatic properties, as well as sustained growth factor release.
Single-ion magnet behavior of Ln3+ encapsulated in carbon nanotubes: an ab initio insight
Authors: Liu Dan , Guo Xuefeng , Zhang Xiaoyong , Al-Kahtani Abdullah A. , Chibotaru Liviu F.
Published: July 2023

The magnetization blocking via the late lanthanide series ions embedded in highly symmetric zigzag carbon nanotubes was studied by ab initio methodology. The results indicated Er3+@(7,0) CNT can be a candidate of efficient single-ion magnet.
Crystallographic elucidation of an aluminium-bound amido Schiff base chemosensor: a selective turn-on fluorescent chemosensor for Al3+ ions
Authors: Hoque Anamika , Islam Md Sanaul , Khan Samim , Datta Basudeb , Zangrando Ennio , Kole Goutam Kumar , Alam Md. Akhtarul
Published: July 2023

A two arm-containing amido Schiff base named bis((2-hydroxynaphthalen-1-yl) methylene)-1,1′-biphenyl-2,2′-dicarbohydrazide was structurally characterized and used for the selective recognition of Al3+ ions through “off–on” fluorescence signalling behaviour.
Robust and efficient transfer hydrogenation of carbonyl compounds catalyzed by NN-Mn(i) complexes
Authors: Wang Zheng , Ma Ning , Lu Xiaochi , Liu Ming , Liu Tian , Liu Qingbin , Solan Gregory A. , Sun Wen-Hua
Published: July 2023

A robust NN-manganese(i) complex has been developed that can efficiently catalyze the TH of a broad range of carbonyl derivatives to their corresponding alcohols with TON's and TOF's as high as 17 200 and TOF of 3550 h−1, respectively.
Urban stormwater microplastic size distribution and impact of subsampling on polymer diversity
Authors: Parmar Swaraj , Arbuckle-Keil Georgia , Kumi G. , Fahrenfeld N. L.
Published: July 2023

Understanding not only microplastic (MP) concentration but also size distribution, morphology, and polymer profiles is desirable for stormwater, which is an important pathway of entry for MP into the aquatic environment.
Druggable targets for the immunopathy of Alzheimer's disease
Authors: Weaver Donald F.
Published: July 2023

Decades of research have yet to identify a disease modifying drug for Alzheimer's disease. This review provides an evaluation of the leading twelve druggable targets (microglial and cytokine), addressing the role of neuroinflammation in Alzheimer's.
A Q-marker screening strategy based on ADME studies and systems biology for Chinese herbal medicine, taking Qianghuo Shengshi decoction in treating rheumatoid arthritis as an example
Authors: Wang Jiao , Tao Cimin , Xu Guangzheng , Ling Jiawei , Tong Jie , Goh Bey Hing , Xu Yipeng , Qian Linghui , Chen Yong , Liu Xuesong , Wu Yongjiang , Xu Tengfei
Published: July 2023

Chinese herbal medicine (CHM) exhibits a broad spectrum of clinical applications and demonstrates favorable therapeutic efficacy.
Novel decorated aluminium(iii) phthalocyanine complex with the application of MWCNTs on electrodes: electrochemical non-enzymatic oxidation and reduction of glucose and hydrogen peroxide
Authors: Mounesh  , Manikanta P. , Reddy K. R. Venugopala , Selvaraj Manickam , Vidyasagar C. C. , Nagaraja Bhari Mallanna
Published: July 2023

In this study, we performed the physicochemical and electrochemical characterization of a decorated macrocyclic aluminium(iii) phthalocyanine complex (AlTMQNCAPc).
Correction: Understanding liquid–liquid equilibria in binary mixtures of hydrocarbons with a thermally robust perarylphosphonium-based ionic liquid
Authors: Bandlamudi Santosh R. P. , McGehee Jimmie L. , Mando Albaraa D. , Soltani Mohammad , Turner C. Heath , Davis James H. , West Kevin N. , Rabideau Brooks D.
Published: July 2023

Correction for ‘Understanding liquid–liquid equilibria in binary mixtures of hydrocarbons with a thermally robust perarylphosphonium-based ionic liquid’ by Santosh R. P. Bandlamudi et al., RSC Adv., 2021, 11, 31328–31338, https://doi.org/10.1039/D1RA06268A
Glassy and compressed nanoemulsions stabilized with sodium dodecyl sulfate in the presence of poly(ethylene glycol)-diacrylate
Authors: Abbasian Chaleshtari Zahra , Salimi-Kenari Hamed , Foudazi Reza
Published: July 2023

Rheology of nanoemulsions containing PEGDA deviates from those of classical models. Dynamic interfacial tension suggests PEGDA is not at the interface. Rheology of glassy nanoemulsions shows higher dependency on PEGDA than that of compressed ones.
Influence of pH on the self-assembly of diphenylalanine peptides: molecular insights from coarse-grained simulations
Authors: Wang Yan , Wang Kang , Zhao Xinyi , Xu Xiaojun , Sun Tingting
Published: July 2023

Nanostructures fabricated from peptide self-assemblies are attracting increasing attention due to their possible applications in biology and nanotechnology.
Phase behaviour of coarse-grained fluids
Authors: Sokhan V. P. , Seaton M. A. , Todorov I. T.
Published: July 2023

Soft condensed matter structures often challenge us with complex many-body phenomena governed by collective modes spanning wide spatial and temporal domains.
Enhanced nickel catalysts for producing electrolytic hydrogen
Authors: Ciriminna Rosaria , Pagliaro Mario
Published: July 2023

This study suggests that lowering the cost of electrolytic hydrogen obtained in water alkaline electrolyzers requires to develop new nanostructured or single-atom Ni-based catalysts and newly shaped electrodes obtained via 3D printing.
Transparent organic photovoltaics with a tungsten oxide buffer layer fabricated by nanosecond laser processing for color-neutral performance
Authors: Hsu I-Sheng , Lee Chih-Chien , Akbar Abdul Khalik , Uma Kasimayan , Liu Shun-Wei
Published: July 2023

WO3 used as LBL reduces thermal damage in laser processing of TPVs. Improved yield from 50% to 83%. Transmittance and electrical properties optimized using hexagonal pattern. Proposed TPV (314 μm width) exhibits color-neutral, 65.84% transmittance.
Attention mechanism based bidirectional LSTM model for broadband power amplifier linearization
Authors: Su Rina , Wang Jiacheng , Xu Gaoming , Liu Taijun
Published: July 2023

In this letter, a novel digital predistortion (DPD) model for broadband power amplifier (PA) linearization is proposed, namely Attention Mechanism based Bidirectional Long Short‐term Memory Network (AM‐BiLSTM) model. In order to verify the linearization performance of the AM‐BiLSTM model in digital predistortion process, a 100 MHz bandwidth 5G new radio (5G NR) signal is employed to test a sub‐6G PA operating at 2.6‐GHz. The experimental results show that the adjacent channel power ratio (ACPR) of the PA with AM‐BiLSTM model can be improved by 24 dB which is 6 dB and 3 dB better than the generalized memory polynomial (GMP) model and the Chebyshev polynomials LSTM (CP‐LSTM) model in ref [1], repspectively. Therefore, the proposed AM‐BiLSTM model is very effective for the DPD linearization of broadband PAs.
Modulating sparks in a pulse train for repetitive and energy efficient plasma generation
Authors: Yin Bo , Zhu Yifei , Wu Yun
Published: July 2023

Spark is a widely studied plasma source for active species production; however, it experiences unstable transitions (e.g. to a thermal arc) at high frequencies or long pulse durations. In this study, the sparks generated in a pulse train were studied and modulated based on a physics‐corrected deep learning method. Our results show that a highly repeatable and stable spark plasma source can be achieved by automatically adjusting the voltage amplitude according to the discharge frequency in a high‐frequency pulse train within the time scale of the fluid response. The influences of the electron number density increasing mode and modulated driven voltage profiles on the energy efficiencies were also studied.
Single‐cell RNA‐seq and bulk RNA‐seq explore the prognostic value of exhausted T cells in hepatocellular carcinoma
Authors: Tang Xiaolong , Miao Yandong , Yang Lixia , Ha Wuhua , Li Zheng , Mi Denghai
Published: July 2023

Hepatocellular carcinoma (HCC) remains a worldwide health problem. Mounting evidence indicates that exhausted T cells play a critical role in the progress and treatment of HCC. Therefore, a detailed characterisation of exhausted T cells and their clinical significance warrants further investigation in HCC. Based on the GSE146115, we presented a comprehensive single‐cell Atlas in HCC. Pseudo‐time analysis revealed that tumour heterogeneity progressively increased, and the exhausted T cells gradually appeared during tumour progression. Functional enrichment analysis revealed that the evolutionary process of exhausted T cells mainly contained the pathway of cadherin binding, proteasome, cell cycle, and T cell receptor regulation of apoptosis. In the International Cancer Genome Consortium database, we divided patients into three clusters with the T cell evolution‐associated genes. We found that the exhausted T cells are significantly related to poor outcomes through immunity and survival analysis. In The Cancer Genome Atlas database, the authors enrolled weighted gene co‐expression network analysis, univariate Cox analysis, and Lasso Cox analysis, then screened the 19 core genes in T cells evolution and built a robust prognostic model. This study offers a fresh view on evaluating the patients' outcomes from an exhausted T cells perspective and might help clinicians develop therapeutic systems.
Variations in the intermediate wind region of the blue supergiant 55 Cygni
Authors: Cidale L. S. , Haucke M. , Arias M. L. , Kraus M. , Campuzano Castro F. , Venero R. O. J. , Mercanti L. , Curé M. , Granada A.
Published: July 2023

Context. The quantitative near-infrared (NIR) spectroscopic synthesis is an important technique for determining wind properties of massive stars. The Brα line is an excellent mass-loss tracer and provides valuable information on the physical conditions of intermediate-wind regions. The knowledge of the wind properties gained by studying the NIR lines could provide extra ingredients to the theory of line-driven winds, mainly because the standard theory does not predict observed properties of blue supergiants, such as high values for the β parameter (β> 2), low terminal velocities, and mass-loss variability.

Aims. We seek to enhance our understanding of the wind properties of B supergiants. To this end, we propose analysing their NIR spectra over different epochs to study wind variability and its connection with phenomena arising from regions close to the photosphere.

Methods. We present the first sets of multi-epoch high-resolution K- and L-band spectra of 55 Cyg acquired with the Gemini Near-InfraRed Spectrograph (GNIRS). We measured line equivalent widths and modelled the Brα line to derive (unclumped) mass-loss rates. Synthetic line profiles were computed for a homogeneous spherical wind by solving the radiative transfer equations in the co-moving frame for a multi-level atom in non-local thermodynamic equilibrium (NLTE).

Results. We observe variations in the spectral lines originating in the upper photosphere and the wind. The perturbations, on average, have periods of ~13 and ~23 days; the latter is similar to that found previously from optical data (22.5 days). The NIR lines observed in 2013 are described with the same wind structure used to model a quasi-simultaneous observation in Hα. By contrast, from observations taken in 2015, we derived a higher mean mass-loss rate. Variations in the mass-loss rate are also detected within a few weeks. Interestingly, we find that the profile shape of the Hu14 line sets constraints on the mass loss. Moreover, we find the Mg II doublet in emission, which suggests a tenuous circumstellar gas ring or shell.

Conclusions. The variability detected in the NIR H emission lines of 55 Cyg is related to changes in the mass-loss rate, which doubled its value between 2013 and 2015. Furthermore, the short-term variability (within three weeks) in the spectral lines and mass loss supports the hypothesis of strange-mode oscillations. This pilot project demonstrates the importance of comprehensive monitoring of blue supergiants’ variability to deeply understand the physical properties of their stellar winds and the role of pulsations in recurrently enhancing mass loss.
Simulating the LOcal Web (SLOW)
Authors: Dolag Klaus , Sorce Jenny G. , Pilipenko Sergey , Hernández-Martínez Elena , Valentini Milena , Gottlöber Stefan , Aghanim Nabila , Khabibullin Ildar
Published: July 2023

Context.Several observations of the Local Universe point toward the existence of very prominent structures: massive galaxy clusters and local superclusters on the one hand, but also large local voids and underdensities on the other. However, it is highly nontrivial to connect such different observational selected tracers to the underlying dark matter (DM) distribution.

Aims.Therefore, constructing mock catalogs of such observable tracers using cosmological hydrodynamics simulations is needed. These simulations have to follow galaxy formation physics and also have to be constrained to reproduce the Local Universe. Such constraints should be based on observables that directly probe the full underlying gravitational field, such as the observed peculiar velocity field, to provide an independent test on the robustness of these distinctive structures.

Methods.We used a 500h−1Mpc constrained simulation of the Local Universe to investigate the anomalies in the local density field, as found in observations. Constructing the initial conditions based on peculiar velocities derived from the CosmicFlows-2 catalog makes the predictions of the simulations completely independent from the distribution of the observed tracer population, and following galaxy formation physics directly in the hydrodynamics simulations also allows the comparison to be based directly on the stellar masses of galaxies or X-ray luminosity of clusters. We also used the 2668h−1Mpc large cosmological box from the Magneticum simulations to evaluate the frequency of finding such anomalies in random patches within simulations.

Results.We demonstrate that halos and galaxies in our constrained simulation trace the local dark matter density field very differently. Thus, this simulation reproduces the observed 50% underdensity of galaxy clusters and groups within the sphere of ≈100 Mpc when applying the same mass or X-ray luminosity limit used in the observed cluster sample (CLASSIX), which is consistent with a ≈1.5σfeature. At the same time, the simulation reproduces the observed overdensity of massive galaxy clusters within the same sphere, which on its own also corresponds to a ≈1.5σfeature. Interestingly, we find that only 44 out of 15 635 random realizations (i.e., 0.28%) match both anomalies, thus making the Local Universe a ≈3σenvironment. We finally compared a mock galaxy catalog with the observed distribution of galaxies in the Local Universe, finding a match to the observed factor of 2 overdensity at ∼16 Mpc as well as the observed 15% underdensity at ∼40 Mpc.

Conclusions.Constrained simulations of the Local Universe which reproduce the main features of the local density field open a new window for local field cosmology, where the imprint of the specific density field and the impact on the bias through the observational specific tracers can be investigated in detail.
A Bayesian estimation of the Milky Way’s circular velocity curve using Gaia DR3
Authors: Põder Sven , Benito María , Pata Joosep , Kipper Rain , Ramler Heleri , Hütsi Gert , Kolka Indrek , Thomas Guillaume F.
Published: July 2023

Aims. Our goal is to calculate the circular velocity curve of the Milky Way, along with corresponding uncertainties that quantify various sources of systematic uncertainty in a self-consistent manner.

Methods. The observed rotational velocities are described as circular velocities minus the asymmetric drift. The latter is described by the radial axisymmetric Jeans equation. We thus reconstruct the circular velocity curve between Galactocentric distances from 5 kpc to 14 kpc using a Bayesian inference approach. The estimated error bars quantify uncertainties in the Sun’s Galactocentric distance and the spatial-kinematic morphology of the tracer stars. As tracers, we used a sample of roughly 0.6 million stars on the red giant branch stars with six-dimensional phase-space coordinates from Gaia Data Release 3 (DR3). More than 99% of the sample is confined to a quarter of the stellar disc with mean radial, rotational, and vertical velocity dispersions of (35 ± 18) km s−1, (25 ± 13) km s−1, and (19 ± 9) km s−1, respectively.

Results. We find a circular velocity curve with a slope of 0.4 ± 0.6 km s−1 kpc−1, which is consistent with a flat curve within the uncertainties. We further estimate a circular velocity at the Sun’s position of vc(R0) = 233 ± 7 km s−1 and that a region in the Sun’s vicinity, characterised by a physical length scale of ∼1 kpc, moves with a bulk motion of VLSR = 7 ± 7 km s−1. Finally, we estimate that the dark matter (DM) mass within 14 kpc is log10 MDM(R < 14kpc)/ M⊙
=(11.2+2.0-2.3) and the local spherically averaged DM density is ρDM(RO)=(0.41+0.10-0.09)
GeV cm-3 = (0.011+0.003-0.002) M⊙pc-3. In addition, the effect of biased distance estimates on our results is assessed.
Estimating the selection function of Gaia DR3 subsamples
Authors: Castro-Ginard Alfred , Brown Anthony G. A. , Kostrzewa-Rutkowska Zuzanna , Cantat-Gaudin Tristan , Drimmel Ronald , Oh Semyeong , Belokurov Vasily , Casey Andrew R. , Fouesneau Morgan , Khanna Shourya , Price-Whelan Adrian M. , Rix Hans-Walter
Published: July 2023

Context. Understanding the intricacies behind the presence and absence of sources in an astronomical catalogue is crucial for the accurate interpretation of astronomical data. In particular, for the multi-dimensional Gaia data, filters and cuts on different parameters or measurements introduce a selection function that may unintentionally alter scientific conclusions in subtle ways.

Aims. We aim to develop a methodology to estimate the selection function for different subsamples of stars in the Gaia catalogue.

Methods. Comparing the number of stars in a given subsample to that in the overall Gaia catalogue provides an estimate of the subsample membership probability as a function of sky position, magnitude, and colour. The method used to make this estimate must differentiate the stochastic absence of subsample stars from selection effects. When multiplied with the overall Gaia catalogue selection function, this provides the total selection function of the subsample.

Results. We present our new method for estimating the selection function by applying it to the sources in Gaia DR3 with heliocentric radial velocity measurements. We also compute the selection function for the stars in the Gaia-Sausage/Enceladus sample, confirming that the apparent asymmetry of its debris across the sky is merely caused by selection effects.

Conclusions. The method we have developed estimates the selection function of the stars present in a subsample of Gaia data, given that the subsample is completely contained in the Gaia parent catalogue (for which the selection function is known). This tool is made available in a GaiaUnlimited Python package.
KMT-2022-BLG-0475Lb and KMT-2022-BLG-1480Lb: Microlensing ice giants detected via the non-caustic-crossing channel
Authors: Han Cheongho , Lee Chung-Uk , Bond Ian A. , Zang Weicheng , Chung Sun-Ju , Albrow Michael D. , Gould Andrew , Hwang Kyu-Ha , Jung Youn Kil , Ryu Yoon-Hyun , Shin In-Gu , Shvartzvald Yossi , Yang Hongjing , Yee Jennifer C. , Cha Sang-Mok , Kim Doeon , Kim Dong-Jin , Kim Seung-Lee , Lee Dong-Joo , Lee Yongseok , Park Byeong-Gon , Pogge Richard W. , Mao Shude , Zhu Wei , Abe Fumio , Barry Richard , Bennett David P. , Bhattacharya Aparna , Fujii Hirosame , Fukui Akihiko , Hamada Ryusei , Hirao Yuki , Ishitani Silva Stela , Itow Yoshitaka , Kirikawa Rintaro , Kondo Iona , Koshimoto Naoki , Matsubara Yutaka , Miyazaki Shota , Muraki Yasushi , Olmschenk Greg , Ranc Clément , Rattenbury Nicholas J. , Satoh Yuki , Sumi Takahiro , Suzuki Daisuke , Toda Taiga , Tomoyoshi Mio , Tristram Paul J. , Vandorou Aikaterini , Yama Hibiki , Yamashita Kansuke
Published: July 2023

Aims. We investigate the microlensing data collected in the 2022 season from high-cadence microlensing surveys in order to find weak signals produced by planetary companions to lenses.

Methods. From these searches, we find that two lensing events, KMT-2022-BLG-0475 and KMT-2022-BLG-1480, exhibit weak short-term anomalies. From a detailed modeling of the lensing light curves, we determine that the anomalies are produced by planetary companions with a mass ratio to the primary of q ~ 1.8 × 10−4 for KMT-2022-BLG-0475L and q ~ 4.3 × 10−4 for KMT-2022-BLG-1480L.

Results. We estimate that the host and planet masses and the projected planet-host separation are (Mh/M⊙, Mp/MU, a⊥/au) = (0.43−0.23+0.35, 1.73−0.92+1.42, 2.03−0.38+0.25) for KMT-2022-BLG-0475L and (0.18−0.09+0.16, 1.82−0.92+1.60, 1.22−0.14+0.15) for KMT-2022-BLG-1480L, where MU denotes the mass of Uranus. The two planetary systems have some characteristics in common: the primaries of the lenses are early-mid M dwarfs that lie in the Galactic bulge, and the companions are ice giants that lie beyond the snow lines of the planetary systems.
Observability of a string-beams network with many beams
Authors: Lai Anna Chiara , Loreti Paola , Mehrenberger Michel
Published: July 2023

We prove the direct and inverse observability inequality for a network connecting one string with infinitely many beams, at a common point, in the case where the lengths of the beams are all equal. The observation is at the exterior node of the string and at the exterior nodes of all the beams except one. The proof is based on a careful analysis of the asymptotic behavior of the underlying eigenvalues and eigenfunctions, and on the use of a Ingham type theorem with weakened gap condition [C. Baiocchi, V. Komornik and P. Loreti, Acta Math. Hung. 97 (2002) 55–95.]. On the one hand, the proof of the crucial gap condition already observed in the case where there is only one beam [K. Ammari, M. Jellouli and M. Mehrenberger, Networks Heterogeneous Media 4 (2009) 2009.] is new and based on elementary monotonicity arguments. On the other hand, we are able to handle both the complication arising with the appearance of eigenvalues with unbounded multiplicity, due to the many beams case, and the terms coming from the weakened gap condition, arising when at least 2 beams are present.
A Systematic Review with Meta-Analysis Investigating the Impact of Targeted Perfusion Parameters during Extracorporeal Cardiopulmonary Resuscitation in Out-of-Hospital and Inhospital Cardiac Arrest
Authors: Saemann Lars , Maier Sven , Rösner Lisa , Kohl Matthias , Schmucker Christine , Scherer Christian , Trummer Georg , Beyersdorf Friedhelm , Benk Christoph
Published: July 2023

Evidence regarding perfusion conditions during extracorporeal cardiopulmonary resuscitation (ECPR) is rare. Therefore, we investigated the impact of perfusion parameters on neurologic outcome and survival in patients with in- or out-of-hospital cardiac arrest (IHCA; OHCA) treated with ECPR. We performed a systematic review with meta-analysis. The focus was set on perfusion parameters and their impact on survival and a goal neurological outcome using the cerebral performance category score of 1–2. We conducted random- and mixed-effects meta-analyses and computed pooled estimates and 95% confidence intervals (CI). We included a total of n = 1,282 ECPR (100%) patients from 20 ECPR studies. The target values of flow and mean arterial pressure (MAP) were frequently available. We transferred flow and MAP target values to high, medium, and low categories. The meta-analysis could not demonstrate a single effect of flow or MAP on outcome variables. In a second mixed-effects model, the combined occurrence of targeted flow and MAP as medium and high showed a significant effect on survival (OHCA: 52%, 95% CI: 29%, 74%; IHCA: 60%, 95% CI: 35%, 85%) and on neurological outcomes (OHCA: 53%, 95% CI: 27%, 78%; IHCA: 62%, 95% CI: 38%, 86%). Random-effects analysis showed also that IHCA led to a significant 11% (p = 0.006; 95% CI: 3%, 18%) improvement in survival and 12% (p = .005; 95% CI: 4%, 21%) improvement in neurological outcomes compared to OHCA. A combination of medium flow and high MAP showed advantages in survival and for neurological outcomes. We also identified improved outcomes for IHCA.
Anticoagulant Use During Extracorporeal Membrane Oxygenation Using Heparin and Direct Thrombin Inhibitors in COVID-19 and ARDS Patients
Authors: Stammers Alfred H. , Tesdahl Eric A. , Barletti Shannon , Mongero Linda , Patel Kirti , Mosca Matthew , Sestokas Anthony , Firstenberg Michael S. , Jacobs Jeffrey P.
Published: July 2023

Coagulopathies develop in patients supported with the use of extracorporeal membrane oxygenation (ECMO) and can be hemorrhagic and/or thrombophilic in spite of the use of systemic anticoagulation. The purpose this study was to examine the use of heparin and direct thrombin inhibitors (DTI) in COVID-19 patients with acute respiratory distress syndrome (ARDS) on ECMO, with a subset analysis by disease state. Following IRB approval, 570 consecutive records were reviewed of adult patients on venovenous ECMO between May 2020 and December 2021. Patients were grouped by anticoagulant use: Heparin Only (n = 373), DTI Only (bivalirudin or argatroban, n = 90), or DTI after Heparin (n = 107). The effect of anticoagulant grouping was assessed using Bayesian mixed-effects logistic regression adjusting for age, body mass index (BMI), gender, days of mechanical ventilation prior to ECMO, indication for ECMO support, hepatic and renal failure, hours on ECMO, hours off anticoagulation, coagulation monitoring target, and hospital. The primary endpoint was circuit failure requiring change-out with secondary endpoints of organ failure and mortality. Regression-adjusted probability of circuit change-outs were as follows: DTI after Heparin patients—32.7%, 95% Credible Interval [16.1–51.9%]; DTI Only patients—23.3% [7.5–40.8%]; and Heparin Only patients—19.8% [8.1–31.3%]. The posterior probability of difference between groups was strongest for DTI after Heparin vs. Heparin Only (97.0%), moderate for DTI after Heparin vs. DTI Only (88.2%), and weak for DTI Only vs. Heparin only (66.6%). The occurrence of both hepatic and renal failure for DTI Only and DTI after Heparin patients was higher than that of Heparin Only patients. Unadjusted mortality was highest for DTI after Heparin (64.5%) followed by DTI Only (56.7%), and Heparin Only (50.1%, p = 0.027). DTI after Heparin was associated with an increased likelihood of circuit change-out. Unadjusted hepatic failure, renal failure, and mortality were more frequent among DTI patients than Heparin Only patients.
Morbidity of Repeat Cesarean Delivery after a Trial of Labor as Compared with Elective Repeat Cesarean Delivery
Authors: Markovic Emily S. , Fox Nathan S.
Published: July 2023

Objective This study aimed to evaluate if a secondary repeat cesarean after a trial of labor (TOLAC) without uterine rupture is associated with increased morbidity as compared with a scheduled elective repeat cesarean delivery (ERCD).

Study Design This was a retrospective cohort study of repeat cesarean delivery (CD) in a single obstetrical practice between 2005 and 2022. Patients were included if they had a singleton pregnancy at term with one prior CD and had a repeat CD this pregnancy resulting in live birth. Patients were excluded if they had a prior myomectomy, more than one prior CD, uterine rupture in a prior or current pregnancy, or placenta previa in this pregnancy. We compared baseline characteristics and outcomes between patients who had a repeat cesarean after TOLAC and ERCD. The primary outcome was a composite of maternal morbidity that included hysterectomy, blood transfusion, cystotomy, bowel injury, intensive care unit admission, thrombosis, reoperation, or maternal mortality.

Results A total of 930 women met inclusion criteria. A total of 176 (18.9%) patients intended to labor and 754 (81.1%) planned an ERCD. There was no difference in the primary outcome between patients with a repeat cesarean after TOLAC compared with patients with ERCD (2.8 vs. 1.2%, p = 0.158). Patients with repeat cesarean after labor had significantly more 1-minute Apgar scores less than 7, but no difference in 5-minute Apgar scores. We were powered to detect a difference in the primary outcome from 1.2% in the ERCD group to 3.3% in the repeat cesarean after labor group. Results did not differ when we analyzed patients who intended to TOLAC versus patients who actually labored prior CD.

Conclusion For women with one prior CD the morbidity of repeat cesarean after labor is not more than the morbidity of planned repeat CD. Our study can be helpful in delivery planning counseling for patients with one prior CD.

Key Points
Opportunities for diamond quantum metrology in biological systems
Authors: Belser Sophia , Hart Jack , Gu Qiushi , Shanahan Louise , Knowles Helena S.
Published: July 2023

Sensors that harness quantum mechanical effects can enable high sensitivity and high spatial resolution probing of their environment. The nitrogen-vacancy defect in diamond, a single, optically accessible electronic spin, is a promising quantum sensor that can operate in soft and living systems and provides nanoscale spatial resolution when hosted inside a diamond nanoparticle. Nanodiamond quantum sensors are nontoxic, amenable to surface functionalization, and can be introduced into a variety of living systems. The optical readout of the spin provides detailed information about the local electromagnetic and thermal environment in a noninvasive way. In this Perspective, we introduce the different modalities that nanodiamond quantum sensors offer, highlight recent progress in quantum sensing of biological systems, and discuss remaining challenges and directions for future efforts.
Quantifying the synchronization of the spikes emitted by coupled lasers
Authors: Tiana-Alsina Jordi , Masoller Cristina
Published: July 2023

Synchronization phenomena is ubiquitous in nature, and in spite of having been studied for decades, it still attracts a lot of attention as is still challenging to detect and quantify, directly from the analysis of noisy signals. Semiconductor lasers are ideal for performing experiments because they are stochastic, nonlinear, and inexpensive and display different synchronization regimes that can be controlled by tuning the lasers’ parameters. Here, we analyze experiments done with two mutually optically coupled lasers. Due to the delay in the coupling (due to the finite time the light takes to travel between the lasers), the lasers synchronize with a lag: the intensity time traces show well-defined spikes, and a spike in the intensity of one laser may occur shortly before (or shortly after) a spike in the intensity of the other laser. Measures that quantify the degree of synchronization of the lasers from the analysis of the intensity signals do not fully quantify the synchronicity of the spikes because they also take into account the synchronization of fast irregular fluctuations that occur between spikes. By analyzing only the coincidence of the spike times, we show that event synchronization measures quantify spike synchronization remarkably well. We show that these measures allow us to quantify the degree of synchronization and, also, to identify the leading laser and the lagging one.
Understanding the piezoelectric response of ZnO nanotetrapods: Detailed numerical calculations
Authors: Zhang Zhiwei , Nan Yang , Mishra Yogendra Kumar , Willatzen Morten , Wang Zhong Lin
Published: July 2023

The complex tetrapod shape of zinc oxide nanostructure, which is constructed from four one-dimensional arms interconnected together via a central core, is a special 3D geometry with multifunctional applications in advanced technologies. The ZnO hexagonal wurtzite crystal lattice with a non-centrosymmetric structure introduces interesting piezoelectric property in nanorods in the bent state, which has been well reported and utilized in piezo- and tribo-electric nanogenerator applications. Considering the broad technological relevance of tetrapods, it is important to understand the piezoelectric response of zinc oxide tetrapods under different conditions. In this study, we explicate the fundamental mechanical and electrical properties of ZnO nanotetrapods (ZnO NTs) through a detailed finite element method analysis. On this basis, the effects of shape factors (including length, height, and aspect ratio) as well as connection strength and packing density on the deformation and piezoelectric potential of ZnO NTs are examined, offering guidance for the fabrication of ZnO NTs. This theoretical model and numerical simulation provide an avenue for further piezoelectric and piezotronic research of ZnO NTs.
In situ study and modeling of the reaction kinetics during molecular beam epitaxy of GeO2 and its etching by Ge
Authors: Chen Wenshan , Egbo Kingsley , Tornatzky Hans , Ramsteiner Manfred , Wagner Markus R. , Bierwagen Oliver
Published: July 2023

Rutile GeO2 has been predicted to be an ultra-wide bandgap semiconductor suitable for future power electronic devices, while quartz-like GeO2 shows piezoelectric properties. To explore these crystalline phases for application and fundamental materials investigations, molecular beam epitaxy (MBE) is a well-suited thin film growth technique. In this study, we investigate the reaction kinetics of GeO2 during plasma-assisted MBE using elemental Ge and plasma-activated oxygen fluxes. The growth rate as a function of oxygen flux is measured in situ by laser reflectometry at different growth temperatures. A flux of the suboxide GeO desorbing off the growth surface is identified and quantified in situ by the line-of-sight quadrupole mass spectrometry. Our measurements reveal that the suboxide formation and desorption limits the growth rate under Ge-rich or high temperature growth conditions and leads to etching of the grown GeO2 layer under a Ge flux in the absence of oxygen. The quantitative results fit the sub-compound mediated reaction model, indicating the intermediate formation of the suboxide at the growth front. This model is further utilized to delineate the GeO2-growth window in terms of oxygen-flux and substrate temperature. Our study can serve as a guidance for the thin film synthesis of GeO2 and defect-free mesa etching in future GeO2-device processing.
Atomic-scale tailoring of chemisorbed atomic oxygen on epitaxial graphene for graphene-based electronic devices
Authors: Kim Tae Soo , Ahn Taemin , Kim Tae-Hwan , Choi Hee Cheul , Yeom Han Woong
Published: July 2023

Graphene, with its unique band structure, mechanical stability, and high charge mobility, holds great promise for next-generation electronics. Nevertheless, its zero bandgap challenges the control of current flow through electrical gating, consequently limiting its practical applications. Recent research indicates that atomic oxygen can oxidize epitaxial graphene in a vacuum without causing unwanted damage. In this study, we have investigated the effects of chemisorbed atomic oxygen on the electronic properties of epitaxial graphene using scanning tunneling microscopy (STM). Our findings reveal that oxygen atoms effectively modify the electronic states of graphene, resulting in a bandgap at its Dirac point. Furthermore, we demonstrate that it is possible to selectively induce desorption or hopping of oxygen atoms with atomic precision by applying appropriate bias sweeps with an STM tip. These results suggest the potential for atomic-scale tailoring of graphene oxide, enabling the development of graphene-based atomic-scale electronic devices.