bluuebunny/crossref_metadata_2025_split huggingface dataset:
Has AMS-02 observed two-component dark matter?
Authors: Profumo Stefano , Queiroz Farinaldo , Siqueira Clarissa 
Published: September 2020

Abstract
There is convincing observational evidence for an increasing cosmic-ray positron-to-electron ratio at energies larger than ∼10 GeV, at odds with expectations from secondary positron production. The most recent AMS-02 data exhibit an interesting spectral feature consisting of a bump at an energy around 300 GeV followed by a drop around ∼800 GeV. A possible explanation for the most recent data is that the excess positron flux originates from decaying dark matter. Here, we show that models consisting of two dark matter particle species contributing equally to the global cosmological dark matter density provide good fits to the data. The favored models, with a best-fit with χ
2/d.o.f ∼ 2, consist of a first species weighing 750 GeV decaying with a lifetime τ

χ
∼ 1026 s to τ lepton pairs (or to a pair of vector bosons subsequently decaying to a τ pair each), and a second species with a mass around 2.3 TeV decaying to μ lepton pairs. We provide a few possible concrete realizations for this scenario.
A new bubbly flow detection and quantification procedure based on optical laser-beam scattering behavior
Authors: Abbaszadeh Mohammad , Alishahi Mohammad Mehdi , Emdad Homayoun 
Published: September 2020

Abstract
In this paper a new bubbly flow measurement procedure is proposed which can be used to both detect and quantify some main features of such flows. The proposed procedure is based on the optical scattering behavior of a laser-beam passing through a bubbly flow. A series of experiments are conducted to evaluate the procedure and important parameters involved such as length of bubbly flow, bubble number density and size distribution. Experimental results confirm the capabilities of the procedure for the detection and quantification of bubbly flows. Also, an optical model of the laser beam behavior in bubbly flow is derived to reevaluate the problem and its results are compared with the obtained experimental results. Outcomes of the optical model, which is in good agreement with the experimental results, emphasizes and describes the strong correlation between the injection strength parameter and forward scattered light intensity. Also, bubble size distribution is found to be in close connection with the amplitude of scattered light fluctuations. Therefore, upon the measurement of optical laser-beam scattering behavior passing through a bubbly flow, various properties of such flows could be determined.
Transfer operator approach to ray-tracing in circular domains
Authors: Slipantschuk J , Richter M , Chappell D J , Tanner G , Just W , Bandtlow O F 
Published: September 2020

Abstract
The computation of wave-energy distributions in the mid-to-high frequency regime can be reduced to ray-tracing calculations. Solving the ray-tracing problem in terms of an operator equation for the energy density leads to an inhomogeneous equation which involves a Perron–Frobenius operator defined on a suitable Sobolev space. Even for fairly simple geometries, let alone realistic scenarios such as typical boundary value problems in room acoustics or for mechanical vibrations, numerical approximations are necessary. Here we study the convergence of approximation schemes by rigorous methods. For circular billiards we prove that convergence of finite-rank approximations using a Fourier basis follows a power law where the power depends on the smoothness of the source distribution driving the system. The relevance of our studies for more general geometries is illustrated by numerical examples.
Pulsed-field magnetisation of Y-Ba-Cu-O bulk superconductors fabricated by the infiltration growth technique
Authors: Namburi Devendra K , Takahashi K , Hirano T , Kamada T , Fujishiro H , Shi Y-H , Cardwell D A , Durrell J H , Ainslie M D 
Published: September 2020

Abstract
Bulk high temperature superconductors based on the rare-earth copper oxides can be used effectively as trapped field magnets capable of generating large magnetic fields. The top-seeded infiltration growth (TSIG) processing technique can provide a more homogeneous microstructure and therefore more uniform superconducting properties than samples grown using conventional melt growth processes. In the present investigation, the properties of bulk, single grain superconductors processed by TSIG and magnetised by the pulsed-field magnetisation technique using a copper-wound solenoid have been studied. A trapped field of ∼3 T has been achieved in a 2-step buffer-assisted TSIG-processed Y-Ba-Cu-O (YBCO) sample at 40 K by magnetising the bulk superconductor completely via a single-pulse magnetisation process. Samples were also subjected to pulsed-field magnetisation at 65 K and by conventional field-cooled magnetisation at 77 K for comparison. Good correlation was observed between the microstructures, critical current densities and trapped field performance of bulk samples fabricated by TSIG and magnetised by pulsed-field and field-cooled magnetisation. The homogeneous distribution of Y2BaCuO5 inclusions within the microstructure of bulk YBCO samples fabricated by the 2-step buffer-assisted TSIG process reduces inhomogeneous flux penetration into the interior of the sample. This, in turn, results in a lower temperature rise of the bulk superconductor during the pulsed-field magnetisation process and a more effective and reliable magnetisation process.
Study of a new layered ternary chalcogenide CuZnTe2 and its potassium intercalation effect
Authors: Islam M K , Sarker M A R , Inagaki Y , Islam M S 
Published: September 2020

Abstract
A new layered ternary chalcogenide CuZnTe2 and its effect due to potassium (K) intercalation have been investigated using ab-initio method under the framework of density functional theory (DFT). Here, we report the structural, electronic and elastic properties of both proposed parent compound CuZnTe2 and intercalated KCuZnTe2. The electronic band structures and the density of states (DOS) of both these chalcogenides have also been studied. The parent compound demonstrates p-type conductivity with the energy band gap of 0.7 eV but surprisingly, the increase of energy gap (1.5 eV) is found in the intercalated KCuZnTe2, a direct-transition type semiconductor. The optical absorption result in KCuZnTe2 also shows the identical value of gap energy calculated by Wood-Tauc theory. The density of states (DOS) in the valence band for both compounds is dominated by the partial contribution of Cu/Zn 3d and Te 5p orbitals but the prime contribution of Cu/Zn 4s and Te 5s mainly in the conduction band DOS. The DOS value at around Fermi level in these chalcogenides is indicating the degeneracy behavior of a semiconductor. Both compounds are mechanically stable and also malleable. We also calculated the thermal properties in the intercalated KCuZnTe2 using quasi-harmonic Debye model. The observed values of Debye temperature, specific heat capacities and volume expansion coefficient using this model is almost consistent with the estimated values given in theory.
Sputtering parameters effect on microstructural parameters of TiN coating via the Williamson-Hall analysis
Authors: Huang Jinghao , Zou Shuliang , Xiao Weiwei , Liu Xiaoshuang , Tang Dewen 
Published: September 2020

Abstract
Titanium nitride (TiN) coatings were deposited on Zr-4 substrate by direct current magnetron sputtering. The microstructural property of the as-deposited coating was studied by means of x-ray diffraction (XRD). The microstructural parameters, such as crystal size, lattice strain, lattice deformation stress and lattice deformation energy density, were investigated in detail by employed modified Debye–Scherrer method (MDS) and Williamson-Hall methods by assuming three models namely uniform deformation model, uniform stress deformation model and uniform energy density deformation model. And the effects of sputtering power, substrate temperature and substrate bias on microstructural parameters were investigated. The results show that TiN coating deposited by magnetron sputtering presents lattice compressive strain, except for sample X3-1 which is prepared by substrate bias of −50 V. It is also shown that sputtering power, substrate temperature and substrate bias have great influence on crystal size, lattice strain, lattice deformation stress and lattice deformation energy density of the as-deposited TiN coating. Especially the influence of substrate bias is very significant.
Effects of Sc on laser hot-wire welding performance of 7075 aluminum alloy
Authors: Li Shichun , Xu Wei , Xiao Gang , Zhou Zhenhong , Su Fei , Feng Jianghua 
Published: September 2020

Abstract
In order to clarify the effects of Sc modification on laser hot-wire welding performance of 7075 high strength aluminum alloys, the changing rules of weld formation, microstructure, element loss, mechanical performances and pores of weld joints were investigated during laser fusion welding, laser hot-wire welding and Sc-modified laser hot-wire welding. Comparing with laser fusion welding, the filler wire in laser hot-wire welding brought welding material and hot wire energy, resulting in better weld formation and sufficient fused weld joint. In laser hot-wire welding, tensile strength and elongation of weld joint were enhanced, element loss of weld joint was dramatically reduced and weld pore was reduced slightly. However, grains in fusion zone were relatively coarse, which caused lower microhardness in laser hot-wire welding. In Sc modified laser hot-wire welding, Sc modification led to smooth and continuous weld joint. During solidification of weld joints, Sc could combine with base metal to form Sc-containing alloy phase, which could lead to the formation of refined and equiaxed grains, thereby enhancing the yield strength of microstructure and increasing the microhardness, tensile strength and elongation of weld joint. In addition, Sc modification could increase the fluidity of molten pool, which thus promoted the escape of bubbles from the molten pool and hindered the formation of weld pores.
Fate of titanium in alkaline electro-reduction of sintered titanomagnetite
Authors: Bjareborn Oscar , Arif Tanzeel , Monaghan Brian , Bumby Chris W 
Published: September 2020

Abstract
Direct electrochemical reduction of iron ore in concentrated NaOH electrolyte has been proposed as a potential route to substantially reducing the global steel industry’s CO2 emissions. Here, we report the solid-state electro-reduction of sintered pellets formed from titanomagnetite ironsand. This commercial iron ore contains ∼4 wt.% Ti which is directly incorporated within the magnetite lattice. At 110 °C, these pellets are electrochemically reduced and exhibit a well-defined reaction front which moves into the pellet as the reaction progresses. The electro-reduction process selectively produces iron metal, whilst the Ti content is not reduced. Instead, Ti becomes enriched in segregated oxide inclusions, which are subsequently transformed to a sodium iron titanate phase through taking up Na+ from the electrolyte. These inclusions adopt an elongated shape and appear to exhibit locally preferential alignment. This suggests that they may nucleate from the microscopic titanohematite lamellae which naturally occur within the original ironsand particles. The expulsion of contaminant Ti-oxides from the final reduced metal matrix has implications for the potential to development of an industrial electrochemical iron-making process utilising titanomagnetite ore.
Impact of antibiotic choice on readmission in adults experiencing an acute COPD exacerbation
Authors: Lancaster Jason W , McAuliffe Laura , O’Gara Elizabeth , Cornelio Cyrille , Hum Jennifer , Kim Yestle , Phung Ann , She Kevin , Lei Yuxiu , Balaguera Henri , Liesching Timothy 
Published: September 2020

Abstract

Purpose
The impact of antibiotic therapy in managing acute chronic obstructive pulmonary disease (COPD) exacerbations requiring hospitalization remains unclear. We conducted a study to assess the impact of antibiotic therapy on the rate of 30-day readmission after discharge from a hospital stay for an acute COPD exacerbation. Additional study outcomes analyzed included the effects of antibiotic therapy on hospital length of stay, in-hospital mortality, 90-day and 12-month readmission rates, and time to next COPD exacerbation.

Methods
The study was an institutional review board–approved, retrospective, observational review of adult patients at a tertiary academic medical center. The medical records of patients 18 years of age or older who were hospitalized for an acute COPD exacerbation between January 2008 and December 2014 were evaluated. Included patients were stratified by receipt of guideline-appropriate, guideline-inappropriate, or no antibiotic therapy. Nonparametric data were analyzed using the Kruskal-Wallis test (nonparametric) and categorical data via χ 2 test, respectively.

Results
Three hundred twenty-five subjects were included; there were no significant differences in baseline characteristics in the 3 study groups. Sixty-eight percent of patients (n = 223) received antibiotics. The percentage of patients readmitted within 30 days did not differ between cohorts: 11.9% (appropriate therapy) vs 13.2% (nonappropriate therapy) vs 12.2% (no antibiotics) (P = 0.95 for all comparisons). Additionally, no detectable differences in 90-day or 12-month readmission rate, length of hospital day, or in-hospital mortality were found. However, a trend toward increased time to next COPD exacerbation was noted in those receiving antibiotics vs no antibiotics (352 days vs 192 days, P = 0.07).

Conclusion
Treatment of COPD exacerbations with antibiotics did not impact readmission rates, length of hospital stay, in-hospital mortality, or time to next exacerbation. More investigation is warranted to assess the effect of antibiotics on time to next exacerbation, as well as comparative effectiveness between antibiotic classes.
Inter Organizational Practice Committee Guidance/Recommendation for Models of Care During the Novel Coronavirus Pandemic
Authors: Postal Karen S , Bilder Robert M , Lanca Margaret , Aase Darrin M , Barisa Mark , Holland Alice Ann , Lacritz Laura , Lechuga David M , McPherson Susan , Morgan Jennifer , Salinas Christine 
Published: September 2020

Abstract

Objective
The Inter Organizational Practice Committee (IOPC) convened a workgroup to develop guidance on models to provide neuropsychological (NP) care during the COVID-19 pandemic while minimizing risks of novel coronavirus transmission as lockdown orders are lifted and ambulatory clinical services resume.

Method
A collaborative panel of experts from major professional organizations developed provisional guidance for models of neuropsychological practice during the pandemic. The stakeholders included the American Academy of Clinical Neuropsychology/American Board of Clinical Neuropsychology, the National Academy of Neuropsychology, Society of Clinical neuropsychology (Division 40) of the American Psychological Association, the American Board of Professional Neuropsychology, and the American Psychological Association Services, Inc.

Results
This guidance reviews the risks and benefits of conducting NP exams in several ways, including standard in-person, mitigated in-person, in-clinic teleneuropsychology (TeleNP), and in-home TeleNP. Strategies are provided for selecting the most appropriate model for a given patient, taking into account four levels of patient risk stratification, level of community risk, and the concept of stepped models of care. Links are provided to governmental agency and professional organization resources as well as an outline and discussion of essential infection mitigation processes based on commonalities across recommendations from diverse federal, state, local, and professional organization recommendations.

Conclusion
This document provides recommendations and guidance with analysis of the risks relative to the benefits of various models of NP care during the COVID-19 pandemic. These recommendations may be revised as circumstances evolve, with updates posted continuously on the IOPC website (https://iopc.online/).
Tc17 CD8+ T cells accumulate in murine atherosclerotic lesions, but do not contribute to early atherosclerosis development
Authors: van Duijn Janine , de Jong Maaike J M , Benne Naomi , Leboux Romain J T , van Ooijen Marieke E , Kruit Nicky , Foks Amanda C , Jiskoot Wim , Bot Ilze , Kuiper Johan , Slütter Bram 
Published: September 2020

AbstractAimsCD8+ T cells can differentiate into subpopulations that are characterized by a specific cytokine profile, such as the Tc17 population that produces interleukin-17. The role of this CD8+ T-cell subset in atherosclerosis remains elusive. In this study, we therefore investigated the contribution of Tc17 cells to the development of atherosclerosis.Methods and resultsFlow cytometry analysis of atherosclerotic lesions from apolipoprotein E-deficient mice revealed a pronounced increase in RORγt+CD8+ T cells compared to the spleen, indicating a lesion-specific increase in Tc17 cells. To study whether and how the Tc17 subset affects atherosclerosis, we performed an adoptive transfer of Tc17 cells or undifferentiated Tc0 cells into CD8−/− low-density lipoprotein receptor-deficient mice fed a Western-type diet. Using flow cytometry, we showed that Tc17 cells retained a high level of interleukin-17A production in vivo. Moreover, Tc17 cells produced lower levels of interferon-γ than their Tc0 counterparts. Analysis of the aortic root revealed that the transfer of Tc17 cells did not increase atherosclerotic lesion size, in contrast to Tc0-treated mice.ConclusionThese findings demonstrate a lesion-localized increase in Tc17 cells in an atherosclerotic mouse model. Tc17 cells appeared to be non-atherogenic, in contrast to their Tc0 counterpart.
Anastomosis behind the sternoclavicular joint is associated with increased incidence of anastomotic stenosis in retrosternal reconstruction with a gastric conduit after esophagectomy
Authors: Kurahashi Yasunori , Ishida Yoshinori , Kumamoto Tsutomu , Nakanishi Yasutaka , Hojo Yudai , Igeta Masataka , Takemura Masashi , Shinohara Hisashi 
Published: September 2020

Abstract
Anastomotic stenosis after esophagectomy is a major cause of long-term morbidity because it leads to poor dietary intake and malnutrition that markedly reduces the quality of life. The aim of this study was to test the hypothesis that anastomosis behind the sternoclavicular (SC) joint in retrosternal reconstruction is associated with an increased risk of anastomotic stenosis compared with anastomosis deviated from the joint. Among 226 patients who underwent esophagectomy for esophageal cancer between April 2010 and March 2019, we selected 114 patients who underwent retrosternal reconstruction using a gastric conduit for this study. They were classified into two groups according to the location of the anastomosis as determined by axial sections on postoperative computed tomography scans: anastomosis located behind the SC joint (Group B; n = 71) and anastomosis deviated from the joint (Group D; n = 43). The primary endpoint was the difference in the incidence of anastomotic stenosis between the two groups. Whether the occurrence of anastomotic leak affected the likelihood of anastomotic stenosis was also investigated. The incidence of anastomotic stenosis was significantly higher in Group B than in Group D (71.8% [n = 51] vs. 18.6% [n = 8]; P &lt; 0.0001). The incidence of stenosis in patients who developed an anastomotic leak was significantly higher in Group B than in Group D (88.0% vs. 41.7%; P = 0.0057), although the findings were similar in patients who did not develop anastomotic leak (63.0% and 9.7%, respectively; P &lt; 0.0001). We conclude that anastomosis located behind the SC joint in retrosternal reconstruction with a gastric conduit after esophagectomy is associated with an increased risk of anastomotic stenosis regardless of the development of anastomotic leak.
Outcome of esophageal atresia in Germany
Authors: Schmedding A , Wittekindt B , Schloesser R , Hutter M , Rolle U 
Published: September 2020

Abstract
The aim of this study was to evaluate the outcome of esophageal atresia in Germany in a retrospective observational study of a large cohort. Data from the major health insurance company in Germany, which covers approximately 30% of German patients, were analyzed. All patients born and registered between 2009 and 2013 with a diagnosis of esophageal atresia at first admission to the hospital were included. Mortality was analyzed during the first year of life. We identified 287 patients with esophageal atresia, including 253 with and 34 without tracheoesophageal fistula. Associated anomalies were found in 53.7% of the patients; the most frequent were cardiac anomalies (41.8%), anomalies of the urinary tract (17.4%), and atresia of the colon, rectum, and anus (9.4%). Forty-one patients (14.3%) had a birth weight &lt;1500 g. Seventeen patients (5.9%) died before surgery. Gastrostomy was performed during the index admission in 70 patients (25.9%). The reconstruction of the esophageal passage was performed in 247 patients (93.9%). Forty-eight percent of the patients who underwent an operation required dilatation. The mortality rate in the patients who underwent an operation was 10.4%. These results from Germany correspond to the international results that have been reported. The number of dilatations was in the middle of the range of those reported in the literature; the overall mortality rate was in the upper portion of the range of the international rates. Efforts should be made to establish a clinical registry to measure and improve the quality of care for this and other rare conditions.
Tyrosine Kinase 2 Signalling Drives Pathogenic T cells in Colitis
Authors: De Vries Leonie C S , Ghiboub Mohammed , van Hamersveld Patricia H P , Welting Olaf , Verseijden Caroline , Bell Matthew J , Rioja Inmaculada , Prinjha Rabinder K , Koelink Pim J , Strobl Birgit , Müller Mathias , D’Haens Geert R , Wildenberg Manon E , De Jonge Wouter J 
Published: September 2020

Abstract

Background and Aims
Tyrosine kinase 2 [TYK2] is required for the signalling of key cytokines in the pathogenesis of inflammatory bowel disease [IBD]. We assessed the efficacy of a novel selective TYK2 inhibitor [TYK2i] in experimental colitis, using pharmacological and genetic tools.

Methods
At onset of T cell transfer colitis, RAG1-/- mice received vehicle or TYK2i daily by oral gavage. T cells lacking TYK2 kinase activity [TYK2KE] were used to confirm selectivity of the inhibitor. To this end, RAG1-/- or RAG1-/-TYK2KE animals were transferred with either wild type [WT] or TYK2KE-CD45RBhigh colitogenic T cells. Loss of body weight, endoscopic disease, the disease activity index [DAI], and histopathology scores were recorded. Tissues were analysed ex vivo for lymphocyte populations by flow cytometry. The impact of TYK2 inhibition on human DC-T cell interactions were studied using autologous Revaxis specific T cell assays.

Results
TYK2i [70 mg/kg] prevented weight loss and limited endoscopic activity during T cell transfer colitis. TYK2i [70 mg/kg] decreased DAI. Whereas transfer of WT T cells into RAG-/-TYK2KE hosts induced colitis, TYK2KE T cells transferred into RAG1-/-TYK2KErecipients failed to do so. Ex vivo analysis showed a decrease in colon tissue Th1 cells and an increase in Th17 cells upon transfer of TYK2KE-CD45RBhigh cells. In human antigen-triggered T cells, TYK2i displayed reduced Th1 differentiation, similar to murine Th1 cells.

Conclusions
Oral administration of TYK2i, as well as transfer of T cells lacking TYK2 activity, reduced human Th1 differentiation and ameliorated the course of murine T cell transfer colitis. We conclude that TYK2 is a promising drug target for the treatment of IBD.