bluuebunny/crossref_metadata_2025_split huggingface dataset:
Broadband flattened underwater acoustic Luneburg lens
Authors: Tong Shuaishuai , Ren Chunyu , Tao Jun , Jiang Lixun 
Published: November 2022

Abstract
Conventional Luneburg lenses are symmetric circular gradient-index lens with no aberration, but they are restricted by their circular focal surface. Here, we show the design, realization and measurement of an underwater acoustic Luneburg lens with flattened focal surface. The flattened lens is designed by using the quasi-conformal transformation technique and constructed by metamaterials based on air-filled photosensitive resin. Through numerical simulations and experimental studies, the flattened lens is demonstrated to have excellent focusing performance for the incident plane waves propagating at desired angles over a broad frequency band from 20 kHz to 35 kHz. The proposed flattened Luneburg lens can be potentially applied in the applications such as biomedical imaging, underwater acoustic sensing and communication.
Interfacial charge transfer induced antiferromagnetic metals and magnetic phase transition in (CrO2)
m
/(TaO2)
n
superlattices
Authors: Shan Wanfei , Luo Weidong 
Published: November 2022

Abstract
As a class of remarkable spintronic materials, intrinsic antiferromagnetic (AFM) metals are rare. The exploration and investigation of AFM metals are still in its infancy. Based on first-principles calculations, the interface-induced magnetic phenomena in the (CrO2)
m
/(TaO2)
n
superlattices are investigated, and a new series of AFM metals is predicted. Under different ratios of

m
:
n

with varying valence states of Cr, the (CrO2)
m
/(TaO2)
n
superlattices exhibit three different phases, including the AFM metal, the AFM semiconductor, and the ferromagnetic (FM) metal. In the AFM semiconducting phases, the intra-CrO2-monolayer magnetic exchange interaction is systematically discussed, corresponding to m = 1 or m = 2. Both the localization of the Cr 3 d orbitals and the crystal-field splitting are crucial for magnetic ordering in super-exchange interactions. Based on the analyses of the AFM semiconducting phases with m = 1 and m = 2, the mechanisms of AFM metallic phases with radios of

m
:
n
<
1

/

2

and

1

/

2
<
m
:
n
<
1

/

1

are discussed in detail. Additionally, the AFM metallic superlattices can be tuned into a FM metallic phase by applying strain in the c-direction, such as a compression of 7% in the (CrO2)1/(TaO2)3 superlattice, and a tensile strain of 7% in the (CrO2)2/(TaO2)3 superlattice. The phase diagram of the (CrO2)
m
/(TaO2)
n
superlattices is obtained as a function of the layer thickness. This work provides new insights about realizing and manipulating AFM metals in artificial superlattices or heterostructures in experiments.
Quasi-continuous dc voltage standard using sinusoidal and pulse-driven Josephson junction arrays
Authors: Georgakopoulos Dimitrios , Budovsky Ilya , Benz Samuel P 
Published: November 2022

Abstract
Josephson voltage standards (JVSs) provide a primary realization of the volt, the unit of electromotive force. They generate direct current (dc) voltages up to 10 V and show agreement better than 1 nV V−1 at 10 V. For JVSs based on Josephson junction arrays (JJAs) that are driven by sinusoidal radiofrequency (RF) power, commonly referred to as continuous wave-driven JJAs (CWD JJAs), the minimum voltage that can be generated is limited to the voltage across one Josephson junction (JJ) for practical devices. To achieve this resolution, they may require a perfect JJA chip. JVSs based on a pulse-driven (PD) JJA require high performance electronics (i.e. high bandwidth, low distortion and jitter, pulse shaping filters and large memory) to achieve their minimum and maximum voltage. We have combined two CWD JJAs and two PD JJAs driven by two microwave inputs to one chip to generate quasi-continuous dc voltages up to the sum of the full-scale voltages of both JJAs that are robust to the imperfections of the JJs and have relaxed requirements on the RF electronics driving the JJA, compared to the existing CWD JVSs and PD JVSs, respectively. By use of the JJA chip at the National Measurement Institute Australia, we demonstrate its feasibility to generate voltages up to 1 V. Preliminary evaluation of the system shows that the voltage uncertainty can be 11 nV (k = 2) or better and the theoretical resolution is better than 1 nV from 0 V to 1 V. The main requirement is that all the JJs must have quantum locking ranges with respect to the power and frequency of the RF bias and for the PD JJAs to have a constant voltage over a range of dc bias current. Although this development is not a replacement for existing state-of-the-art JVSs, we anticipate that it will be an alternative fit-for-purpose solution for metrological applications under non-ideal operating conditions or when the components of the state-of-the-art solutions are not available.
Diffraction imaging of light induced dynamics in xenon-doped helium nanodroplets
Authors: Langbehn B , Ovcharenko Y , Clark A , Coreno M , Cucini R , Demidovich A , Drabbels M , Finetti P , Di Fraia M , Giannessi L , Grazioli C , Iablonskyi D , LaForge A C , Nishiyama T , Oliver Álvarez de Lara V , Peltz C , Piseri P , Plekan O , Sander K , Ueda K , Fennel T , Prince K C , Stienkemeier F , Callegari C , Möller T , Rupp D 
Published: November 2022

Abstract
We explore the light induced dynamics in superfluid helium nanodroplets with wide-angle scattering in a pump–probe measurement scheme. The droplets are doped with xenon atoms to facilitate the ignition of a nanoplasma through irradiation with near-infrared laser pulses. After a variable time delay of up to 800 ps, we image the subsequent dynamics using intense extreme ultraviolet pulses from the FERMI free-electron laser. The recorded scattering images exhibit complex intensity fluctuations that are categorized based on their characteristic features. Systematic simulations of wide-angle diffraction patterns are performed, which can qualitatively explain the observed features by employing model shapes with both randomly distributed as well as structured, symmetric distortions. This points to a connection between the dynamics and the positions of the dopants in the droplets. In particular, the structured fluctuations might be governed by an underlying array of quantized vortices in the superfluid droplet as has been observed in previous small-angle diffraction experiments. Our results provide a basis for further investigations of dopant–droplet interactions and associated heating mechanisms.
Influence of charge on anisotropic class-one solution in non-minimally coupled gravity
Authors: Sharif M , Naseer Tayyab 
Published: November 2022

Abstract
This paper studies charged star models associated with anisotropic matter distribution in

f
(

,

,

)

theory, where


=



ϕ
ψ



ϕ
ψ

. For this purpose, we take a linear model of this gravity as


+
ζ


, where ζ represents a coupling constant. We consider a self-gravitating spherical geometry in the presence of electromagnetic field and generate solution to the modified field equations by using the ‘embedding class-one’ condition and

MIT

bag model equation of state. The observational data (masses and radii) of four different stellar models like 4U 1820-30, SAX J 1808.4-3658, SMC X-4 and Her X-I is employed to analyze the effects of charge on their physical properties. Finally, the effect of the coupling constant is checked on the viability, hydrostatic equilibrium condition and stability of the resulting solution. We conclude that the considered models show viable and stable behavior for all the considered values of charge and ζ.
Got plenty of nothing: cosmic voids as a probe of particle dark matter
Authors: Arcari S. , Pinetti E. , Fornengo N. 
Published: November 2022

Abstract
The search for a particle dark matter signal in terms of radiation produced by dark matter annihilation or decay has to cope with the extreme faintness of the predicted signal and the presence of masking astrophysical backgrounds. It has been shown that using the correlated information between the dark matter distribution in the Universe with the fluctuations of the cosmic radiation fields has the potential to allow setting apart a pure dark matter signal from astrophysical emissions, since spatial fluctuations in the radiation field due to astrophysical sources and dark matter emission have different features. The cross-correlation technique has been proposed and adopted for dark matter studies by looking at dark matter halos (overdensities). In this paper we extend the technique by focusing on the information on dark matter distribution offered by cosmic voids, and by looking specifically at the gamma-ray dark matter emission: we show that, while being underdense and therefore producing a reduced emission as compared to halos, nevertheless in voids the relative size of the cross-correlation signal due to decaying dark matter vs. astrophysical sources is significantly more favourable, producing signal-to-background ratios S/B (even significantly) larger than 1 for decay lifetimes up to 2 × 1030 s. This is at variance
with the case of halos, where S/B is typically (even much) smaller than 1. We show that forthcoming galaxy surveys such as Euclid combined with future generation gamma-ray detectors with improved specifications have the ability to provide a hint of such a signal with a predicted significance up to 5.7σ for galaxies and 1.6σ for the cosmic shear. The bound on the dark matter lifetime attainable exploiting voids is predicted to improve on current bounds in a mass range for the WIMP of 25 ÷ 900 GeV.
Identifying subdominant collective effects in a large motorway network
Authors: Wang Shanshan , Schreckenberg Michael , Guhr Thomas 
Published: November 2022

Abstract
In a motorway network, correlations between parts or, more precisely, between the sections of (different) motorways, are of considerable interest. Knowledge of flows and velocities on individual motorways is not sufficient, rather, their correlations determine or reflect, respectively, the functionality of and the dynamics on the network. These correlations are time-dependent as the dynamics on the network is highly non-stationary. Apart from the conceptual importance, correlations are also indispensable to detect risks of failure in a traffic network. Here, we proceed with revealing a certain hierarchy of correlations in traffic networks that is due to the presence and to the extent of collectivity. In a previous study, we focused on the collectivity motion present in the entire traffic network, i.e. the collectivity of the system as a whole. Here, we manage to subtract this dominant effect from the data and identify the subdominant collectivities which affect different, large parts of the traffic network. To this end, we employ a spectral analysis of the correlation matrix for the whole system. We thereby extract information from the virtual network induced by the correlations and map it on the true topology, i.e. on the real motorway network. The uncovered subdominant collectivities provide a new characterization of the traffic network. We carry out our study for the large motorway network of North Rhine-Westphalia, Germany.
Analysis of wind speed deviations between floating lidars, fixed lidar and cup anemometry based on experimental data
Authors: Wolken-Möhlmann Gerrit , Bischoff Oliver , Gottschall Julia 
Published: November 2022

Floating lidar system (FLS) measurements are essential for offshore site assessment. Here an important part is the data accuracy and uncertainty, which are determined by the wind speed deviations between the FLS and reference data obtained during a verification trial. The reference anemometer is normally a cup anemometer installed on a met mast. Due to the different measurement principles, mast wake effects, the distance between FLS and reference, and FLS motions, the share of these factors in the deviations are not clear.
In this work, we present an FLS verification measurement conducted in proximity to the FINO3 met mast located in the North Sea in 2017. Additionally, the data acquired by a fixed, non-moving lidar installed on FINO3 is considered. This allows studying wind speed deviations with different, well-defined influence factors.
Methods for analyzing the wind speed accuracy and uncertainty, which are used in FLS verification and classification, are presented and applied to all combinations of data sources. As a preliminary work, directional wind speed deviations are studied to define a valid wind direction sector used for filtering for all data sources.
As a result, the wind speed deviations between the FLS and the references are dominated by the FLS motion and the distance to the reference, respectively. Nevertheless, uncertainties may also be seen for the fixed lidar. For the classification results, approximately 1/3 of the sensitivity is contributed by the different measurement principles.
Method validation of an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) assay for the analysis of Magnesium, Copper and Zinc in RBC
Authors: Bithi Nazmin , Ricks Daniel , Zuromski Lauren M , Kish-Trier Erik , Johnson-Davis Kamisha L 
Published: November 2022

Abstract

Background
Laboratory measurements of trace elements such as magnesium (Mg), copper (Cu) and zinc (Zn) in red blood cells (RBCs) are used to assess nutritional status and diagnose metal toxicity. The purpose of this study was to develop/validate an ICP-MS method for the quantification of these elements in RBCs.

Methods
An aliquot of packed RBCs was diluted in alkaline diluent solution containing scandium (45Sc) and gallium (71Ga), as internal standards, 0.1% Triton X-100, 0.1% EDTA, and 1% ammonium hydroxide (NH4OH). The diluted specimen was aspirated onto an ICP-MS for quantitative analysis of  25Mg,  63Cu and  66Zn. The method was validated for accuracy, precision, method comparison, linearity, analytical sensitivity, and carryover. Retrospective data was analyzed and non-parametric reference intervals (RIs) were calculated.

Results
Accuracy and linearity were within the expected range of =±15% for all analytes. Within-run, between-run, and total imprecisions were =15% CV. All other validation experiments met acceptance criteria. Established RIs for Mg, Cu and Zn in RBCs are 3.6-7.5 mg/dL, 59.0-91.0 mcg/dL and 794.0-1470.0 mcg/dL, respectively. Retrospective analysis of patient data for Mg RBC displayed no statistically significant difference in mean concentrations between adults (&gt;18+ yr) and children (0-18 yr) (p &gt;0.05); however, there was a significant difference in Mg concentrations between males and females (p &lt; 0.001). The mean and SD for Mg RBC concentration for females and males were 5.38 + 0.68 mg/dL (n=8451) and 5.42 + 0.68 mg/dL (n=3954) respectively. The 95% RI was 4.2-6.9 mg/dL; &gt;99% of patient results were within the established RI. Cu RBC mean concentrations were not statistically significant between males and females (p&gt; 0.05) and age differences were not evaluated due to the low number of pediatric patients (n=37). The mean and SD for Cu concentrations were 72.2 + 11.7 mcg/dL (n=423). The overall 95% RI was 54.3-96.3 mcg/dL; 88.9% of patient results were within the established RI. For Zn RBC, there was a statistically significant difference in mean concentrations between children and adults (p &lt; 0.0001) and no statistically significant difference between sex (p &gt; 0.05). The mean and SD for Zn concentrations in children were 1103.7 + 225.5 mcg/dL (n=188). The 95% RI for this subgroup was 707.3– 1547.6 mcg/dL; 87.8% of pediatric patients were within the established RI. In adults, the mean and SD for Zn concentrations were 1311.7 + 196.2 mcg/dL (n=1579). The 95% RI was 932.5 – 1718.3 mcg/dL; 83.3% of patient results were within the established RI.

Conclusions
This method was validated and met criteria for clinical use to quantify three elements using ICP-MS for biological monitoring. Retrospective data analysis of patient results demonstrated that the method was suitable to assess nutritional deficiency and toxicity.
Compliance or Abuse? Detectable hydromorphone in patients taking oxycodone
Authors: Villalba Cristina Figueroa , Choucair Ibrahim , El-Khoury Joe 
Published: November 2022

Abstract
A middle-aged woman with recent cervical diskectomy with spinal fusion at C3-C4 suffered a mechanical fall with bilateral upper extremity paresthesia requiring admission but no surgical intervention. Patient was seen by orthopedic service and was recommended to continue using Aspen collar and oxycodone for pain. Following discharge, a drug urine screen test was performed, and showed positive for oxycodone by immunoassay. Confirmatory urine test by liquid chromatography-tandem mass spectrometry (LC-MS/MS) showed detectable oxycodone, oxymorphone and hydromorphone.
In patients treated with opioid therapy for chronic pain, urine drug monitoring is an important tool to ensure that patients are adhering to the prescribed medication. Hydrocodone and hydromorphone are not metabolites of oxycodone. However, hydrocodone can be present in oxycodone preparations with an estimated impurity of &lt;1%. Hydrocodone can be metabolized into hydromorphone, although, there is no literature reporting detectable hydromorphone in patients’ urine with prescribed oxycodone only.
This case resulted in a quality improvement project where we evaluated the detection of hydrocodone and hydromorphone in positive oxycodone urine samples using LC-MS/MS. We analyzed 322 oxycodone positive urine samples. Twenty-one samples (6%) had detectable hydrocodone and/or hydromorphone below 100 ng/mL. Twelve out of the 21 were from patients taking no opioid medication other than oxycodone in the last week, with 33.3% showing detectable hydromorphone and 75% for hydrocodone below 100 ng/dL. The calculated hydrocodone/oxycodone (HC/OC) and hydromorphone/oxycodone (HM/OC) ratios were on average 0.26% HC/OC = 0.26% (0.05-0.69% SD 0.002; HM/OC = 0.26% (0.18-0.37% SD 0.001)] each (&lt;1%). Patients taking oxycodone and other opioids had ratios &gt;1% [HC/OC = 168% (3-563% SD 2.53; HM/OC = 699% (1.09-6585% SD 15.96)] and had higher detected levels (&gt;100 ng/mL).
Pain management can be very challenging; therefore, laboratory testing provides an objective assessment of drug exposure and adherence to treatment. Cut-off values for considering positive the detection of hydrocodone and hydromorphone may change the interpretation of the drug urine tests in patients with prescribed oxycodone. Using higher cutoff (100 ng/mL) and the ratios HC/OC and HM/OC (&lt;1%) may be useful to determine that the detection of these components is due to impurity of oxycodone formulation.
HLA-B evolutionary divergence is associated with poor outcomes after SARS-CoV-2 infection
Authors: Hernandez Patricia , Duffy Brian , Hock Karl , Farnsworth Christopher , Schindler Emily , Liu Chang 
Published: November 2022

Abstract

Objectives
Human leukocyte antigens (HLA) are highly diverse transmembrane proteins that present viral peptides to T cells and launch pathogen-specific immune responses. We aim to investigate the correlation between HLA evolutionary divergence (HED), a surrogate for the capacity to present different peptides, and the outcomes of SARS-CoV-2 infection in a cohort from the St. Louis Metropolitan area.

Methods
We enrolled adult patients with SARS-CoV-2 infection confirmed by RT-PCR who were hospitalized at two tertiary hospitals in St. Louis between March and July 2020. Genomic DNA was extracted from peripheral blood and genotyped by next-generation sequencing (NGS). HLA alleles were assigned based on key-exon sequences (G group) and limited to the 2-field resolution. HED was calculated by Grantham distance, which considers the difference in composition, polarity, and molecular volume between each pair of amino acids from maternal and paternal HLA. The HED score was obtained for HLA class I (HLA-A, -B, and -C) genotypes using the HLAdivR package in R. Clinical data were collected retrospectively from electronic medical records. A poor outcome was defined as an admission to the intensive care unit (ICU), a need for mechanical ventilation, or death. A favorable outcome was defined as the absence of the above poor outcomes.

Results
A total of 234 patients were enrolled in this study, 96 being females (41%). The median age and BMI were 66 years old and 28.30 kg/m2, respectively. African Americans comprised 71.4% of the cohort. Only 19 patients (8.1%) presented with no comorbidity; the rest had one or more comorbidities, with cardiovascular diseases being the most common. A total of 137 (58.5%) patients had poor outcomes from SARS-CoV-2 infection, while 97 (41.5%) patients had a favorable outcome. We detected a significant association between higher HLA-B HED and favorable outcomes, with each 1-point increase in HLA-B HED associated with 8% increased probability for the composite endpoint (OR 1.08, 95% CI=1.01-1.16, P = 0.04). The HED scores calculated for HLA-A or HLA-C were not significantly different between patients with favorable or poor outcomes. In a multivariate logistic regression analysis, increased HLA-B HED score, younger age, and no comorbidity were independently associated with favorable outcomes (P = 0.02, P = 0.01, and P = 0.05, respectively).

Conclusion
Our study shows a significant correlation between lower HLA-B HED scores and poor outcomes after SARS-CoV-2 infection. This finding suggests that maximizing the presentation of diverse SARS-CoV-2 peptides by HLA-B alleles may improve the clearance of SARS-CoV-2. Further studies are warranted to understand the functional and mechanistic implications of this finding.