bluuebunny/crossref_metadata_2025_split huggingface dataset:
A stellar census in globular clusters with MUSE
Authors: Latour M. , Calamida A. , Husser T.-O. , Kamann S. , Dreizler S. , Brinchmann J. 
Published: September 2021

Context. ω Cen is a rare example of a globular cluster where the iron abundance of the stars spans more than one order of magnitude. Many spectroscopic investigations of its red-giant and sub-giant branches have revealed multiple peaks in the iron abundance distribution. The metallicity distribution of main sequence (MS) stars is not well characterized yet due to the faintness of the stars and lack of data. So far, almost all studies of MS stars have been based on photometric measurements.
Aims. Our goal is to investigate the metallicity distribution of a statistically significant sample of MS stars in ω Cen. In particular, we aim to revisit the metallicity difference between the red and blue MS of the cluster.
Methods. We used MUSE spectra obtained for the central region of ω Cen to derive metallicities for ≈4200 MS stars.
Results. We find that blue MS stars are, on average, ≈0.1 dex more metal-rich than their red counterparts. On the basis of this new estimate, we find that the two sequences can be fit on the Hubble Space Telescope color-magnitude diagram with two isochrones having the same global metallicity and age, but a higher helium abundance for the blue MS, that is ΔY ≲ 0.1. Furthermore, we determined the average metallicity of the five main populations along ω Cen MS and these estimates are consistent with expectations from previous photometric studies.
Exploring the Effect of Long Naps on Handball Performance and Heart Rate Variability
Authors: Nishida Masaki , Yamamoto Kei , Murata Yusuke , Ichinose Atsushi , Shioda Kohei 
Published: September 2021

AbstractThis study explored the effect of long naps on handball-related performance and assessed the role of the cardiac autonomic nervous system in this process. Eleven male collegiate handball players performed a repeated sequential trial consisting of a 20-m consecutive turnaround run, 10-m run with a load, and shooting the ball into a target. Participants were allocated randomly and sequentially to have a short (20 minutes) nap, long (60 minutes) nap, or no nap. The Pittsburgh Sleep Quality Index was used to assess regular sleep quality. Subjective sleepiness before and after napping was measured using the Karolinska Sleepiness Scale. Heart rate variability was recorded to assess cardiac autonomic nervous function during napping. The Pittsburgh Sleep Quality Index score was correlated with shot accuracy only after long naps (ρ=0.636, r=0.048). A negative correlation was observed between the root mean square of successive differences and average load run time (ρ=−0.929, p<0.001). Long napping was associated with a significant benefit on performance in athletes with poor sleep quality, implying a role of the autonomic nervous system in this regard. Our findings indicate the effect of sleep quality on the endurance and resistance of handball players.
Substituição do calcar cimentado versus hemiartroplastia de haste longa cimentada em fraturas intertrocantéricas instáveis em octogenários
Authors: Khatri Kavin , Banga Ravinder Kumar , Malhotra Neeraj , Bansal Deepak 
Published: September 2021

Resumo
Objetivo O objetivo do presente estudo foi comparar os resultados funcionais após a substituição do Calcar cimentado em comparação com a hemiartroplastia cimentada de haste longa em pacientes com mais de 80 anos com fratura intertrocantérica instável.
Métodos O presente estudo prospectivo e randomizado incluiu 140 pacientes com fratura de fêmur intertrocantérica, conforme classificação AO/OTA tipo 31-A2, A3, randomizados em 2 grupos de tratamento e acompanhados por um período mínimo de 2 anos. Sessenta e sete pacientes do grupo A foram tratados com uma prótese de substituição do calcar cimentada e 65 pacientes do grupo B foram tratados com uma prótese femoral de haste longa cimentada. Os desfechos primários foram as funções do quadril em 2 anos. Os eventos secundários foram as complicações encontradas, a mortalidade, o tempo cirúrgico, segunda cirurgia, perda de sangue e as atividades do cotidiano.
Resultados Não houve grandes diferenças entre os grupos em termos de função do quadril, qualidade de vida (relacionada à saúde), segunda cirurgia, mortalidade e perda de sangue. No entanto, a função da articulação do quadril e as atividades da vida diária se deterioraram em ambos os grupos em comparação com os níveis pré-fratura.
Conclusão Nos octogenários com fratura intertrocantérica instável, a prótese de substituição do calcar cimentada apresentou resultados clínicos semelhantes em comparação com a hemiartroplastia de haste longa cimentada. A hemiartroplastia com qualquer um dos implantes é uma boa opção nesse subgrupo de pacientes. Nível de evidência: I
Structure and magnetic properties of ferrimagnetic [Gd/Fe]n multilayer and GdxFe100−x thin films
Authors: Hintermayr Julian , Ullrich Aladin , Albrecht Manfred 
Published: September 2021

The structural and magnetic properties of two series of [Gd(2, 4 nm)/Fe(t)]n multilayer films with varying Fe thickness were investigated and compared to those of amorphous ferrimagnetic GdFe alloys of the same corresponding composition. Transmission electron microscopy studies confirmed the high interface quality of both multilayer series. Furthermore, the microstructure was analyzed, revealing polycrystallinity in both Gd and Fe layers with strong (101̄0)-oriented textured growth of Gd particularly for the multilayer series with 2 nm Gd. Magnetic measurements confirm an out-of-plane magnetic easy axis in the alloy samples and an in-plane magnetic easy axis in all multilayer samples. Twisted spin states in samples with a low remanent magnetization were identified. Magnetic compensation points of both multilayer series are compared to those of the alloy samples. It was found that the dependence of the magnetic compensation point on effective Gd concentration in the series with 2 nm Gd closely resembles the strong dependence observed in the alloy counterparts. In contrast, a weaker dependence is revealed for the multilayer series with 4 nm Gd, which makes this system more robust against variations in composition required for applications.
Transport properties of the binary gas mixtures containing CO2, N2, SF6, and CF4 at low density
Authors: Jiang Tao , Meng Xiangzhao , Jin Lijun 
Published: September 2021

The transport properties at low density are investigated in the framework of the kinetic theory of gases for five binary mixtures composed of CO2, N2, SF6, and CF4, which are of great interest to the electric power industry and are not available in the literature. The Lennard-Jones (12–6) potentials recommended in the literature are used to model the interactions between like molecules, and the Lorentz–Berthelot combining rules are employed to further describe the unlike interactions. The viscosity, binary diffusion coefficient, and thermal diffusion factor are computed for CO2–SF6, CO2–CF4, N2–SF6, N2–CF4, and SF6–CF4. The experimental data are available for the viscosity and diffusion coefficient of the studied systems over a much limited temperature range, and reasonable agreement is found between the experimental data and our calculated values. The new transport property values of the five binary mixtures are tabulated in the supplementary material, covering a very wide temperature range from 300 to 30 000 K.
A novel dual-band nested transit time oscillator
Authors: Gao Xingfu , Song Lili , He Juntao , Ling Junpu , Zhang Peng , Dang Fangchao , Wang Lei 
Published: September 2021

A novel dual-band nested transit time oscillator (TTO) is proposed in this paper, which consists of an outer X-band coaxial TTO and an inner Ka-band coaxial TTO. It is capable of generating dual-band microwaves simultaneously with three distinctive features. First, the emission processes of inner and outer annular electron beams are independent. Second, the inner and outer high frequency structures are spatially isolated. Third, the inner and outer annular electron beams share the guiding magnetic field. Particle-in-cell simulation is performed where a voltage of 450 kV and a guiding magnetic field of 0.6 T are used. Simulation results demonstrate that microwave output with a frequency of 8.4 GHz and a power of 1.72 GW is obtained for the X-band, corresponding to a conversion efficiency of 42% and a microwave saturation time of 30 ns. Meanwhile, microwave output with a frequency of 31.3 GHz and a power of 1.18 GW is achieved for the Ka-band, corresponding to a conversion efficiency of 40% and a microwave saturation time of 15 ns.
On minimal energy solutions to certain classes of integral equations related to soliton gases for integrable systems*
Authors: Kuijlaars Arno , Tovbis Alexander 
Published: September 2021

Abstract
We prove existence, uniqueness and non-negativity of solutions of certain integral equations describing the density of states u(z) in the spectral theory of soliton gases for the one dimensional integrable focusing nonlinear Schrödinger equation (fNLS) and for the Korteweg–de Vries (KdV) equation. Our proofs are based on ideas and methods of potential theory. In particular, we show that the minimising (positive) measure for a certain energy functional is absolutely continuous and its density u(z) ⩾ 0 solves the required integral equation. In a similar fashion we show that v(z), the temporal analog of u(z), is the difference of densities of two absolutely continuous measures. Together, the integral equations for u, v represent nonlinear dispersion relation for the fNLS soliton gas. We also discuss smoothness and other properties of the obtained solutions. Finally, we obtain exact solutions of the above integral equations in the case of a KdV condensate and a bound state fNLS condensate. Our results is a step towards a mathematical foundation for the spectral theory of soliton and breather gases, which appeared in work of El and Tovbis (2020 Phys. Rev. E
101 052207). It is expected that the presented ideas and methods will be useful for studying similar classes of integral equation describing, for example, breather gases for the fNLS, as well as soliton gases of various integrable systems.
Fabrication of new non-hazardous tungsten carbide epoxy resin bricks for low energy gamma shielding in nuclear medicine
Authors: Abualroos Nadin Jamal , Zainon Rafidah 
Published: September 2021

Abstract

Introduction. The main aim of this study was to fabricate a lead-free tungsten carbide epoxy resin brick that has similar shielding properties to lead brick for low energy gamma shielding in nuclear medicine. The attenuation properties of bricks were characterized by using gamma transmission principle in Single-Photon Emission Computed Tomography (SPECT) scanner. Materials and methods. In this study, various percentage of tungsten carbide epoxy resin were fabricated into brick with thickness of 0.5 cm, 1.0 cm, 1.5 cm and 2.0 cm. Tungsten carbide epoxy resin and lead bricks were irradiated with gamma rays from 99mTc to evaluate the radiation attenuation properties. A detector was used to evaluate the gamma shielding performance at 140 keV. The activity of the radioactive source was measured and recorded. The radiation attenuation of tungsten carbide epoxy resin bricks was compared with lead brick of same size and thickness. The gamma transmission was evaluated by using SPECT. Results. Results showed that tungsten carbide epoxy resin brick attenuates more radiation than a lead brick of the same thickness. This study also found that tungsten carbide epoxy resin brick is an effective radiation shielding material compared to lead. The best tungsten carbide and epoxy resin combination was found with a mixture of 90%:10% by weight, respectively. The study showed that both half-value layer and mean free path are higher at thicker samples for all materials at 140 keV. This study found that tungsten carbide and tungsten carbide epoxy resin bricks have small half-value layer and mean free path compared to lead brick. The values were 0.07 cm and 0.06 cm for lead and tungsten carbide, respectively. Conclusion. This study showed that attenuation coefficient measurement can be performed using gamma transmission principle in SPECT. Tungsten carbide epoxy resin shows high potential to replace lead as radiation shielding material.
Assessment of the Oxidative Potential and Oxidative Burden from Occupational Exposures to Particulate Matter
Authors: Fleck Alan da Silveira , Debia Maximilien , Ryan Patrick Eddy , Couture Caroline , Traub Alison , Evans Greg J , Suarthana Eva , Smargiassi Audrey 
Published: September 2021

Abstract
Oxidative potential (OP) is a toxicologically relevant metric that integrates features like mass concentration and chemical composition of particulate matter (PM). Although it has been extensively explored as a metric for the characterization of environmental particles, this is still an underexplored application in the occupational field. This study aimed to estimate the OP of particles in two occupational settings from a construction trades school. This characterization also includes the comparison between activities, sampling strategies, and size fractions. Particulate mass concentrations (PM4-Personal, PM4-Area, and PM2.5-Area) and number concentrations were measured during three weeks of welding and construction/bricklaying activities. The OP was assessed by the ascorbate assay (OPAA) using a synthetic respiratory tract lining fluid (RTLF), while the oxidative burden (OBAA) was determined by multiplying the OPAA values with PM concentrations. Median (25th–75th percentiles) of PM mass and number concentrations were 900 (672–1730) µg m–3 and 128 000 (78 000–169 000) particles cm–3 for welding, and 432 (345–530) µg m–3 and 2800 (1700–4400) particles cm–3 for construction. Welding particles, especially from the first week of activities, were also associated with higher redox activity (OPAA: 3.3 (2.3–4.6) ρmol min–1 µg–1; OBAA: 1750 (893–4560) ρmol min–1 m–3) compared to the construction site (OPAA: 1.4 (1.0–1.8) ρmol min–1 µg–1; OBAA: 486 (341–695) ρmol min–1 m–3). The OPAA was independent of the sampling strategy or size fraction. However, driven by the higher PM concentrations, the OBAA from personal samples was higher compared to area samples in the welding shop, suggesting an influence of the sampling strategy on PM concentrations and OBAA. These results demonstrate that important levels of OPAA can be found in occupational settings, especially during welding activities. Furthermore, the OBAA found in both workplaces largely exceeded the levels found in environmental studies. Therefore, measures of OP and OB could be further explored as metrics for exposure assessment to occupational PM, as well as for associations with cardiorespiratory outcomes in future occupational epidemiological studies.
Effect of diglyceryl dicaprylate on Candida albicans growth and pathogenicity
Authors: Koide Tomojiro , Tamura Muneaki 
Published: September 2021

ABSTRACT
The antifungal effect of diglyceryl dicaprylate, one of the emulsifiers used as a food additive, on Candida albicans that is a pathogenic fungus that is predominant in the oral cavity was investigated. This component did not affect C. albicans growth; however, it suppressed some virulence factors in a concentration-dependent manner. Furthermore, the suppression of pathogenic factors, such as biofilm formation, adhesion, highly pathogenic dimorphism, and ability to produce proteolytic enzymes, was due to reduction in mRNA expression levels of genes involved in fungal pathogenicities. From these results, this emulsifier could potentially prevent the development of intraoral and extraoral diseases involving C. albicans and could potentially use in oral care and improvement of quality of life.
Impact of preoperative breast MRI on 10-year survival of patients included in the Swedish randomized multicentre POMB trial
Authors: Gonzalez V , Arver B , Löfgren L , Bergkvist L , Sandelin K , Eriksson S 
Published: September 2021

Abstract

Background
The value of preoperative breast MRI as an adjunct technique regarding its effect on re-excision rates has been a subject of discussion. No survival data regarding preoperative breast MRI are available from randomized studies.

Methods
Ten-year follow-up of the POMB randomized multicentre study was analysed, evaluating MRI and its effect on disease-free survival (DFS) and overall survival (OS). Patients with newly diagnosed breast cancer were randomized to either preoperative MRI or conventional imaging. Kaplan–Meier plots were used to analyse DFS and OS, and Cox regression to estimate hazard ratios (HRs).

Results
A total of 440 patients, aged 56 years or less, with newly diagnosed breast cancer were randomized to either preoperative MRI (220) or conventional imaging (220; control). Median follow-up for each group was 10 years. DFS rates were 85.5 and 80.0 per cent for the MRI and control groups respectively (P = 0.099). The risk of relapse or death was 46 per cent higher in the control group (HR 1.46, 95 per cent c.i. 0.93 to 2.29). OS rates after 10 years were 90.9 and 88.6 per cent in the MRI and control groups respectively (P = 0.427). The risk of death was 27 per cent higher in the control group (HR 1.27, 0.71 to 2.29). Locoregional, distant, and contralateral recurrence outcomes combined were increased in the control group (P = 0.048). A subgroup analysis of patients with breast cancer stages I–III showed that preoperative MRI improved DFS compared with conventional imaging, but this did not reach statistical significance (P = 0.057).

Conclusion
After 10 years of follow-up, preoperative breast MRI as an adjunct to conventional imaging resulted in slightly, but non-significantly, improved DFS and OS. Registration number: NCT01859936 (http://www.clinicaltrials.gov).
Infectious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Exhaled Aerosols and Efficacy of Masks During Early Mild Infection
Authors: Adenaiye Oluwasanmi O , Lai Jianyu , Bueno de Mesquita P Jacob , Hong Filbert , Youssefi Somayeh , German Jennifer , Tai S H Sheldon , Albert Barbara , Schanz Maria , Weston Stuart , Hang Jun , Fung Christian , Chung Hye Kyung , Coleman Kristen K , Sapoval Nicolae , Treangen Todd , Berry Irina Maljkovic , Mullins Kristin , Frieman Matthew , Ma Tianzhou , Milton Donald K 
Published: September 2021

Abstract

Background
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks and variants on aerosol shedding are not well understood.

Methods
We recruited coronavirus disease 2019 (COVID-19) cases to give blood, saliva, mid-turbinate and fomite (phone) swabs, and 30-minute breath samples while vocalizing into a Gesundheit-II, with and without masks at up to 2 visits 2 days apart. We quantified and sequenced viral RNA, cultured virus, and assayed serum samples for anti-spike and anti-receptor binding domain antibodies.

Results
We enrolled 49 seronegative cases (mean days post onset 3.8 ± 2.1), May 2020 through April 2021. We detected SARS-CoV-2 RNA in 36% of fine (≤5 µm), 26% of coarse (&gt;5 µm) aerosols, and 52% of fomite samples overall and in all samples from 4 alpha variant cases. Masks reduced viral RNA by 48% (95% confidence interval [CI], 3 to 72%) in fine and by 77% (95% CI, 51 to 89%) in coarse aerosols; cloth and surgical masks were not significantly different. The alpha variant was associated with a 43-fold (95% CI, 6.6- to 280-fold) increase in fine aerosol viral RNA, compared with earlier viruses, that remained a significant 18-fold (95% CI, 3.4- to 92-fold) increase adjusting for viral RNA in saliva, swabs, and other potential confounders. Two fine aerosol samples, collected while participants wore masks, were culture-positive.

Conclusions
SARS-CoV-2 is evolving toward more efficient aerosol generation and loose-fitting masks provide significant but only modest source control. Therefore, until vaccination rates are very high, continued layered controls and tight-fitting masks and respirators will be necessary.
A Patient-Prioritized Agenda for Information Needs During the COVID-19 Pandemic: A Qualitative Study of Patients With Inflammatory Bowel Disease
Authors: Long Millie D , Grewe Mary E , Cerciello Emily , Weisbein Laura , Catabay Kyra , Kappelman Michael D 
Published: September 2021

Abstract

Background
Patients with inflammatory bowel disease (IBD) may be at risk for complications due to the COVID-19 pandemic. We performed a qualitative study to better understand IBD patient experiences and concerns when navigating the COVID-19 pandemic, with the goal of prioritizing patients’ information needs.

Methods
We conducted a series of semistructured virtual focus groups at 6 months, then member checking focus groups 1 year into the COVID-19 pandemic. We included questions on patients’ experiences navigating the pandemic with IBD, differences in their experience as compared to peers, their concerns and fears, as well as preferred information sources. Transcribed focus groups were coded and content analyzed to summarize key areas of interest and identify themes. We focused on 4 areas in our content analysis process: fears, challenges, information preferences, and research questions.

Results
A total of 26 IBD patient participants were included in the initial focus groups. Findings highlighted the many challenges faced by patients during the COVID-19 pandemic, ranging from access (bathrooms, medications, healthcare) to significant fears and concerns surrounding medications used for IBD worsening risks of COVID-19. Research questions of importance to patients centered on understanding risks for COVID-19 complications, particularly pertaining to medication utilization, with a shift over time toward understanding COVID-19 vaccination. In our member checking focus groups (n = 8 participants), themes were reiterated, with a central focus of research questions pertaining to COVID-19 vaccination.

Conclusions
Information needs for patients during the COVID-19 pandemic centered upon understanding disease-specific risks. Identified challenges and fears will inform future research agendas and communication with patients.