bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oceanic phytoplankton are a potentially important source of benzenoids to the remote marine atmosphere
Authors: Rocco Manon , Dunne Erin , Peltola Maija , Barr Neill , Williams Jonathan , Colomb Aurélie , Safi Karl , Saint-Macary Alexia , Marriner Andrew , Deppeler Stacy , Harnwell James , Law Cliff , Sellegri Karine 
Published: August 2021

AbstractBenzene, toluene, ethylbenzene and xylenes can contribute to hydroxyl reactivity and secondary aerosol formation in the atmosphere. These aromatic hydrocarbons are typically classified as anthropogenic air pollutants, but there is growing evidence of biogenic sources, such as emissions from plants and phytoplankton. Here we use a series of shipborne measurements of the remote marine atmosphere, seawater mesocosm incubation experiments and phytoplankton laboratory cultures to investigate potential marine biogenic sources of these compounds in the oceanic atmosphere. Laboratory culture experiments confirmed marine phytoplankton are a source of benzene, toluene, ethylbenzene, xylenes and in mesocosm experiments their sea-air fluxes varied between seawater samples containing differing phytoplankton communities. These fluxes were of a similar magnitude or greater than the fluxes of dimethyl sulfide, which is considered to be the key reactive organic species in the marine atmosphere. Benzene, toluene, ethylbenzene, xylenes fluxes were observed to increase under elevated headspace ozone concentration in the mesocosm incubation experiments, indicating that phytoplankton produce these compounds in response to oxidative stress. Our findings suggest that biogenic sources of these gases may be sufficiently strong to influence atmospheric chemistry in some remote ocean regions.
Avaliação da influência hormonal em pacientes com fraturas atribuídas a osteoporose
Authors: Malheiros-Souza Danila , Gaia Leonardo Franco Pinheiro , Sousa Fausto Fernandes de Almeida , Favaro Pedro Ivo Ferreira , Rodrigues Virmondes , Rodrigues Denise Bertulucci Rocha 
Published: August 2021

Resumo
Objetivo Avaliar a influência dos níveis hormonais de vitamina D, calcitonina, testosterona, estradiol e paratormônio em pacientes com fratura atribuída a osteoporose, quando comparados com pacientes jovens que tiveram fraturas decorrentes de acidente de alto impacto.
Métodos Foram coletadas amostras de sangue de 30 pacientes idosos com fratura atribuída a osteoporose (T-score ≤ -2,5) (grupo com osteoporose) e 30 amostras de sangue de pacientes jovens que sofreram fraturas decorrentes de acidentes de alto impacto (grupo controle). Foram realizadas dosagem de 1,25-hidroxivitamina D (Kit Diasorin, Saluggia, Italy), calcitonina (Kit Siemens, Tarrytown, NY, USA), testosterona, estradiol e paratormônio (Kit Beckman Couter, Indianapolis, IN, United States) pela técnica de quimiluminescência. Os dados foram inseridos em uma planilha de dados no programa Microsoft Excel (Microsoft Corp., Redmond, WA, EUA) e analisados pelo programa de estatística Statview. Os resultados que apresentaram distribuição não normal foram analisados com métodos não paramétricos. Para análise de variáveis comparando-se os dois grupos, aplicou-se o teste Mann-Whitney. Foi utilizado o teste de correlação de Spearman para a correlacionar os níveis hormonais. Um valor-p >0.05 foi considerado significante. Todas as análises foram feitas comparando gênero e grupos de pacientes com e sem osteoporose.
Resultados Mulheres com osteoporose apresentam níveis significativamente menores de estradiol e vitamina D (p = 0.047 e p = 0.0275), respectivamente. Homens com osteoporose demonstraram níveis significativamente maiores de paratormônio (p = 0.0065). Não houve diferença significativa nos níveis de testosterona e calcitonina.
Conclusão Existem diferenças hormonais entre os gêneros na osteoporose. Em mulheres, níveis significativamente menores de estradiol e vitamina D e, nos homens, níveis significativamente maiores de paratormônio, parecem influenciar na doença.
Beam Profiling of Dental Light Curing Units Using Different Camera-Based Systems
Authors: Rocha Mateus Garcia , Oliveira Dayane , Felix Christopher , Roulet Jean-François , Sinhoreti Mário Alexandre Coelho , Correr Américo Bortolazzo 
Published: August 2021

Abstract
Objective This study aimed to perform the beam profile of dental light-curing units (LCUs) using mirrorless and smartphone cameras and correlate it to a camera-based laser beam profiling system.
Materials and Methods Three LCUs were evaluated (Radii Plus; Bluephase G2; and VALO Cordless). The spectral power of the LCUs was measured by using a spectrophotometer. The light emitted from the LCUs was projected onto a glass diffuser, and the images were recorded by using a mirrorless camera (NEX-F3), a smartphone (iPhone) and a camera-based beam profiler. Bandpass optical-filters were used, and for each LCU, the total spectral power output was integrated to calibrate the images. Statistical analysis was performed by digital image correlation (pixel by pixel) using Pearson’s correlation (α = 0.05; β = 0.2).
Results The beam profile images showed nonuniform radiant emittance and spectral emission distributions across all the LCUs light tip. A strong correlation was found among cameras (Pearson’s r = 0.91 ± 0.03 with 95% confidence interval [CI]: 0.88–0.94 for the NEX-F3 and Pearson’s r = 0.88 ± 0.04 with 95% CI: 0.84–0.92 for the iPhone).
Conclusion The standard Ophir beam profile system presented the most accurate distribution, but the mirrorless and smartphone cameras presented a strong correlation in the irradiance distribution of the beam profile images. Alternative cameras can be used to perform light beam profile of dental LCUs, but caution is needed as the type of sensor, image bit depth, and image processing are important to obtain accurate results.
Comparative Evaluation of Distribution of Stresses in Osseointegrated Crestal and Basal Implant in Zygomatic Region of Maxilla
Authors: Thakur Prakhar , Kalra Tarun , Kumar Manjit , Bansal Ajay , Malik Shefali 
Published: August 2021

Abstract
Aim The aim of this study was to evaluate the distribution of stresses in osseointegrated crestal and basal implant in zygomatic region of maxilla and to identify the preferable implant option for better stress distribution.
Material and Method The present in vitro study was performed to evaluate stress patterns in bone around basal and crestal dental implant under axial and oblique loading in maxillary zygomatic region with the help of a finite element analysis (FEA). To conduct this study, the following materials were used: computer software ANSYS, basal implants with dimensions 3.7 × 10 mm, and crestal implants with dimensions 3.7 x 10 mm. The amount of load transferred on the bone adjacent to the implant in an axial and transverse load of 100 N at 0 and 45 degrees, respectively, was placed on both types of implants. A three-dimensional (3D) scanner was use to generate 3D simulated model of basal and crestal implants. FEA modelling was generated that replicated the zygomatico maxillary region with special emphasis on bone architecture, bone density, angulation, width, and length of implant prototype. Further, material properties were defined for cortical bone, dense trabecular bone, low density trabecular bone, and titanium on the basis of Young’s modulus of elasticity.
Results These values were used by FEA software (ANSYS) to generate a 3D mesh model of bone and implant. Finally, Von Mises (equivalent stress) (MPa) values on the implant were computed using FEA software. The values of maximum Von Mises equivalent stress on the implant collars, body, apex, and bony interface were obtained.
Conclusion Maximum stresses were seen at the cortical bone with basal implant placed inside the bone. Stresses that are transferred more to the bone through implant promote bone remineralization. Maximum Von Mises stresses were observed on basal implant body. Thus, these greater stresses have the capacity to simulate mineralization in the cortical bone; this makes basal implant a suitable option for placement inside the cortical bone.
Association of Sociodemographic, Obstetric, and Attitudinal Factors with Prenatal Ultrasound in Mashhad, Iran
Authors: Jarahi Lida , Mahmoudi Rahil , Yazd Mohsen Vazifedar , Ghodsi Hamidreza , Ramezani Mohammad , Omranzadeh Alireza 
Published: August 2021

AbstractMany antenatal sonographies are out of indication and may be asked due to mothers' requests or other factors. However, these features are not fully understood. This study aimed to assess the association of sociodemographic, obstetric, and attitudinal factors that may affect the number of ultrasound scans. In a cross-sectional study in six hospitals affiliated with Mashhad University of Medical Sciences, 360 mothers who had a delivery or were expected to be near childbirth were enrolled in the study. The mean number of sonographies was compared between different study variables by using Mann–Whitney, Kruskal–Wallis, and Pearson's Chi-squared tests. Moreover, the Spearman Rho test was used to assess the correlation between different variables and the number of sonographies. Totally, 300 cases remained in the study. The mean age of the mothers was 25.95 ± 4.77 years, and the average number of ultrasonographies was 3.50 ± 1.35. In case of sociodemographic features, the level of education (r = 0.23; p < 0.001) and several recent miscarriages (r = 0.140; p = 0.01) were correlated with number of sonographies. However, there was no association between maternal age and marriage age with several sonographies (p > 0.05). Furthermore, mothers with higher family income (p = 0.010), those with medical insurance (p = 0.010), those who had male fetuses (p = 0.020), those who were clerk or student (p = 0.003), and those who were not aware of the sonography risks (p = 0.020) had more requests for sonography. It seems that financial factors and awareness of sonography risks play an essential role in sonography requests by mothers.
SARS-CoV-2 Exposure from Health Care Workers to Infants: Effects and Outcomes
Authors: Shaiba Lana A. , Hadid Adnan , Abdulghani Sahar H. , Hussain Shaikh A. , Shah Prakesh S. 
Published: August 2021

Objective This study aimed to evaluate the risk and outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission from positive health care workers (HCW) to infants in the neonatal intensive care unit (NICU) and the postnatal ward.
Study Design We conducted a retrospective analysis of infants in NICU and the postnatal ward postexposure to a COVID-19 positive HCW between May 1 and July 31, 2020. HCW had the detection of SARS-CoV-2 after being symptomatic. Infants exposed to these HCW were tested for SARS-CoV-2 and were classified as confirmed positive when test was positive 24 hours after exposure; confirmed negative when test was negative with no escalation of respiratory support provided; and probable if test was negative. However, infant required escalation of respiratory support. Infants were followed at 14 days postexposure then at the end of the study period for admitted infants.
Results A total of 31 infants were exposed to SARS-CoV-2 positive HCWs (42 exposure incidences). The median age at exposure was 21 days. None of the infants was confirmed positive. Nine infants were classified as probable cases of whom five infants with underlying chronic illnesses died, two were discharged home, and two were still admitted. Of the 22 confirmed negative cases, 15 were discharged and were well on follow-up, and 7 were still admitted.
Conclusion No active transmission of infection from infected HCW to admitted infants was identified. Although some infants had respiratory escalation postexposure none were confirmed positive. Adhering to personal protective equipment by HCW or low susceptibility of infants to SARS-CoV-2 infection may explain the lack of transmission.
Key Points
Spatiotemporal isotropic-to-anisotropic meta-atoms
Authors: Pacheco-Peña Victor , Engheta Nader 
Published: August 2021

Abstract
Metamaterials and metasurfaces are designed by spatially arranging (periodically or non-periodically) subwavelength geometries, allowing a tailored manipulation of the electromagnetic response of matter. Here, we exploit temporal variations of permittivity inside subwavelength geometries to propose the concept of spatiotemporal meta-atoms having time-dependent properties. We exploit isotropic-to-anisotropic temporal boundaries within spatially subwavelength regions where their permittivity is rapidly changed in time. In so doing, it is shown how resulting scattered waves travel in directions that are different from the direction of the impinging wave, and depend on the values of the chosen anisotropic permittivity tensor. To provide a full physical insight of their performance, multiple scenarios are studied numerically such as the effect of using different values of permittivity tensor, different geometries of the spatiotemporal meta-atom and time duration of the induced isotropic-to-anisotropic temporal boundary. The intrinsic asymmetric response of the proposed spatiotemporal meta-atoms is also studied demonstrating, both theoretically and numerically, its potential for an at-will manipulation of scattered waves in real time. These results may open new paradigms for controlling wave–matter interactions and may pave the way for the next generation of metamaterials and metasurfaces by unleashing their potential using four-dimensional unit cells.
Probing the magnetization switching with in-plane magnetic anisotropy through field-modified magnetoresistance measurement
Authors: Hao Runrun , Zhang Kun , Li Yinggang , Cao Qiang , Zhang Xueying , Zhu Dapeng , Zhao Weisheng 
Published: August 2021

AbstractEffective probing current-induced magnetization switching is highly required in the study of emerging spin–orbit torque (SOT) effect. However, the measurement of in-plane magnetization switching typically relies on the giant/tunneling magnetoresistance measurement in a spin valve structure calling for complicated fabrication process, or the non-electric approach of Kerr imaging technique. Here, we present a reliable and convenient method to electrically probe the SOT-induced in-plane magnetization switching in a simple Hall bar device through analyzing the MR signal modified by a magnetic field. In this case, the symmetry of MR is broken, resulting in a resistance difference for opposite magnetization orientations. Moreover, the feasibility of our method is widely evidenced in heavy metal/ferromagnet (Pt/Ni20Fe80and W/Co20Fe60B20) and the topological insulator/ferromagnet (Bi2Se3/Ni20Fe80). Our work simplifies the characterization process of the in-plane magnetization switching, which can promote the development of SOT-based devices.
Azimuth Control for Large Aperture Telescope Based on Segmented Arc Permanent Magnet Synchronous Motors
Authors: Song Xiao-Li , Wang Da-Xing , Zhou Wang-Ping 
Published: August 2021

AbstractA tracking control algorithm based on active disturbance rejection controller (ADRC) is proposed to overcome the telescope’s mount fluctuation. The fluctuations are caused by internal and external disturbance when the large aperture telescope runs at ultra-low speed with direct drive. According to the high-precision and high-stability requirements of a large aperture telescope, the ADRC position controller is designed based on segmented arc Permanent Magnet Synchronous Motors (arc PMSMs). The tracking differentiator of ADRC is designed to undergo a transition process to avoid overshoot in the position loop. The speed of target tracking process is observed by the extended state observer and the position information in the system is estimated in real time. The current control variable of the segmented arc PMSM is generated by implementing a non-linear state error feedback control law. The simulation results demonstrate that the proposed control strategy can not only accurately estimate the position and speed of the tracking target, but also estimate the disturbance to compensate the control variables. Experiments showed that the speed error is less than 0.05′ s−1when using the ADRC, and it can realize high tracking performance when compared with PID controller, which improves the robustness of a large aperture telescope control system.
Ice lines as the origin for the gap/ring structure in protoplanetary disks: the issue of the assumed temperature profile
Authors: Liu Yao 
Published: August 2021

Abstract
Gaps and rings are commonly seen in recent high-resolution ALMA observations of protoplanetary disks. Ice lines of volatiles are one of the mechanisms proposed to explain the origin for these substructures. To examine the ice line hypothesis, literature studies usually parameterize the mid-plane temperature with the analytic formula of a passively heated, flared disk. The temperature in this simplified expression is basically dependent on the stellar luminosity. I have built a grid of self-consistent radiative transfer models that feature the same stellar properties, but different disk parameters. The mid-plane temperature of these models shows a large dispersion over a wide range of radii, indicating that besides the stellar luminosity, the disk parameters also play an important role in determining the thermal structure. Comparing the mid-plane temperature from radiative transfer simulation with the analytic solution shows a large difference between both approaches. This result suggests that special care on the assumed temperature profile has to be taken in the analysis of gap/ring origins, and conclusions drawn in previous works on the basis of the analytic temperature should be revisited. I further took the AS 209 disk as an example, and conducted a detailed radiative transfer modeling of the spectral energy distribution and the ALMA Band 6 image. The D137, D24 and D9 gaps are associated with the ice lines of major volatiles in the disk according to such a thorough analysis. However, if the temperature profile simply follows the analytic formula, none of these gaps matches the ice lines of the species considered here.
A new method for resolving phase ambiguity in radio interferometry using Earth rotation synthesis
Authors: Zhou Huan , Xu De-Zhen , Yan Jian-Guo , Chen Shao-Wu , Li Hai-Tao 
Published: August 2021

Abstract
As a key technique in deep space navigation, radio interferometry can be used to determine the accurate location of a spacecraft in the plane-of-sky by measuring its signal propagation time delay between two remote stations. To improve the measurement accuracy, differential phase delay without phase ambiguity is usually desired. Aiming at the difficulties of resolving phase ambiguity with few stations and narrowband downlink signals, a new method is proposed in this work by taking advantage of the Earth rotation. The high accurate differential phase delay between the spacecraft and a calibrator can be achieved not only in the in-beam observation mode but also in the out-of-beam observation mode. In this paper we firstly built the model of phase ambiguity resolution. Then, main measurement errors of the model are analyzed, which is followed by tests and validations of the model and method using the tracking data of the Cassini mission and Chang’E-3 mission. The results show that the phase ambiguities can be correctly resolved to generate a 10-picosecond level accuracy differential phase delay. Angular measurement accuracy of the Cassini reaches the milli-arc-second level, and the relative position accuracy between the Chang’E-3 rover and lander reaches the meter level.
The likely counterpart to γ-ray excess from the northwest region of Arp 220
Authors: Xiang Yun-Chuan , Deng Jun-Hao , Jiang Ze-Jun 
Published: August 2021

Abstract
The unknown γ-ray excess in the northwest region of Arp 220 was revisited by analyzing ∼11.8 years of the Fermi Large Area Telescope (Fermi-LAT) data in this study. We found that its photon flux was approximately three times higher than that of the previous study in the 0.2–100 GeV band, and the corresponding significance level ∼ 8.15σ was approximately four times higher than before. The light curves of 15 and 45 time bins from the whole time all showed two active periods, and the variability of the second period was more significant than that of the first period. The spectral indices from the two active periods were not statistically different and were close to the range of γ-ray flat-spectrum radio quasars observed by Fermi-LAT. Because the position of CRATES J153246+234400 was consistent with the best-fit position of our analysis, we suggest that CRATES J153246+234400 is more likely a γ-ray counterpart for the variational region. For Arp 220, there was no significant variability in the γ-ray emission.
Orbits of 152 globular clusters of the MilkyWay galaxy constructed from Gaia DR2
Authors: Bajkova Anisa Talgatovna , Bobylev Vadim Vadimovich 
Published: August 2021

Abstract
We present orbits and their properties for 152 globular clusters of the Milky Way galaxy obtained using average Gaia DR2 proper motions and other astrometric data from the list of Vasiliev. For orbital integration we have applied the axisymmetric model of the Galactic potential based on the Navarro-Frenk- White dark halo, and modified by Bajkova & Bobylev utilizing circular velocities of Galactic objects in a wide region of Galactocentric distances (up to 200 kpc) from the Bhattacharjee et al. catalog. Based on the analysis of the obtained orbits, we have modified the composition of the subsystems of globular clusters presented in Massari et al.
Expansion series of the pairwise velocity generating function and its implications on redshift space distortion modeling
Authors: Chen Jun-De , Zhang Peng-Jie , Zheng Yi 
Published: August 2021

Abstract
The pairwise velocity generating function G has a deep connection with both the pairwise velocity probability distribution function and modeling of redshift space distortion (RSD). Its implementation into RSD modeling is often faciliated by expansion into a series of pairwise velocity moments

〈

v

12

n

〉

. Motivated by the logrithmic transformation of the cosmic density field, we investigate an alternative expansion into series of pairwise velocity cumulants

〈

v

12

n

〉

c

. We numerically evaluate the convergence rate of the two expansions, with three 30723 particle simulations of the CosmicGrowth N-body simulation series. (1) We find that the cumulant expansion performs significantly better, for all the halo samples and redshifts investigated. (2) For modeling RSD at k
∥ < 0.1h Mpc−1, including only the n = 1,2 cumulants is sufficient. (3) But for modeling RSD at k
∥ = 0.2h Mpc−1, we need and only need the n = 1,2,3,4 cumulants. These results provide specific requirements on RSD modeling in terms of m-th order statistics of the large-scale structure.