bluuebunny/crossref_metadata_2025_split huggingface dataset:
The dipper population of Taurus seen with K2
Authors: Roggero Noemi , Bouvier Jérôme , Rebull Luisa M. , Cody Ann Marie 
Published: June 2021

Context. Dippers are typically low-mass, pre-main-sequence stars that display dips in their light curves. These dips have been attributed to dusty warps that form in the inner part of the disk.
Aims. Our goal is to derive the characteristics of dipper stars in Taurus to assess the physical mechanisms that induce dipper light curves.
Methods. We used the light curves of the fourth and thirteenth campaigns of K2 to select a dipper sample among 179 members and possible members of the Taurus star-forming region based on the light-curve morphology. We studied the periodicities by combining periodograms with wavelet analysis and derived the stellar parameters of the sample from the photometry. We also studied the morphology of the photometric dips.
Results. We find a dipper occurrence of ~30% in disk-bearing stars observed with K2 that were identified visually by us. This represents a lower limit to their true occurrence, on the one hand because they are ephemeral, and on the other because there are detection limits. About half of the dippers are aperiodic, and most of these are dominated by another type of variability. The chosen sample is of late spectral type (K/M), low mass (mostly <1 M⊙), and moderate mass accretion rates and has periods of a few days. We observed a transient dipper over a few rotation cycles and observed a dipper with a changing period. The structure of the dips can be complex and varies strongly over timescales of down to one stellar rotation. The corotation radii are located at a few stellar radii, and the temperatures at corotation allow dust survival. Many of the systems are seen at moderate to high inclination. We find that the angular extension of the dusty structure producing the dips is correlated with the stellar period.
Conclusions. Magnetospheric accretion, which causes an accretion column and its base to occult the star, can explain most of the observed light curves. Although compatible with the model, many of the stellar inclination angles are moderate and do not exclude mechanisms other than the occultation by an inner disk warp to account for dipper light curves.
Widespread occurrence of high-velocity upflows in solar active regions
Authors: Yardley S. L. , Brooks D. H. , Baker D. 
Published: June 2021

Aims. We performed a systematic study of 12 active regions (ARs) with a broad range of areas, magnetic fluxes, and associated solar activity in order to determine whether there are upflows present at the AR boundaries and, if these upflows exist, whether there is a high-speed asymmetric blue wing component present in them.
Methods. To identify the presence and locations of the AR upflows, we derive relative Doppler velocity maps by fitting a Gaussian function to Hinode/EIS Fe XII 192.394 Å line profiles. To determine whether there is a high-speed asymmetric component present in the AR upflows, we fit a double Gaussian function to the Fe XII 192.394 Å mean spectrum that is computed in a region of interest situated in the AR upflows.
Results. Upflows are observed at both the eastern and western boundaries of all ARs in our sample, with average upflow velocities ranging between −5 and −26 km s−1. A blue wing asymmetry is present in every line profile. The intensity ratio between the minor high-speed asymmetric Gaussian component compared to the main component is relatively small for the majority of regions; however, in a minority of cases (8/30) the ratios are large and range between 20 and 56 %.
Conclusions. These results suggest that upflows and the high-speed asymmetric blue wing component are a common feature of all ARs.
One-Pot Synthetic Approaches for the Construction of Isochroman-4-ones and Benzoxazin-3-ones Using O,P-Acetals
Authors: Maegawa Tomohiro , Nakamura Akira , Yamamoto Kouhei , Murakami Ryo , Kawashita Norihito , Matsumoto Kouichi 
Published: June 2021

AbstractA method for synthesizing six-membered heterocyclic compounds was developed based on the features of O,P-acetals. Sequential reactions of intramolecular cyclization between the methylene carbon atom of O,P-acetal and its electrophilic functional group (ester or protected carbamate) was followed by Horner–Wadsworth–Emmons (HWE) olefination with various aldehydes. The developed one-pot method yielded isochroman-4-one and benzoxazin-3-one derivatives with an alkylidene moiety.
Synthesis of a Glycosylphosphatidylinositol (GPI) Fragment as a Potential Substrate for Mannoprotein Transglycosidases
Authors: Belz Tyson F. 
Published: June 2021

AbstractA glycophosphatidylinositol tetrasaccharide fragment was synthesized to mimic the core features of primary model, that of Saccharomyces cerevisiae. The salient feature of this approach is centered on the quick access to various α-1,2- and α-1,6-mannosyl and α-1,4-glycosyl linkages by using simple glycosylation and protective-group techniques. 1D and 2D-J-resolved NMR spectroscopy was used to verify the α-configuration of the new linkages. The tetrasaccharides obtained in this work are useful for examining fungal cell-wall glycoprotein cross-linking by transglycosidase enzymes for antifungal drug development.
Percutaneous Transhepatic and Translumbar Sclerotherapy of a Thoracic Duct Cyst: A Case Report
Authors: Alrashidi Ibrahim , Shin Ji Hoon 
Published: June 2021

AbstractA 58-year-old male presented with chronic abdominal pain lasting 5 years and a 15 × 6-cm multicystic thoracic duct cyst with three compartments, located in the right retrocrural and retrocardiac regions from T5/T6 to T12/L1. A transhepatic route was selected to sclerose the middle and lower compartments. Subsequent contrast injection showed minimal contrast passage into the upper compartment through a narrow neck, but the guidewire could not pass into this compartment. The contrast-filled upper compartment was punctured with a 22-g Chiba needle using a translumbar approach under cone-beam computed tomography (CT) guidance and ethanol sclerotherapy was performed. Six-month follow-up CT revealed decreased thoracic duct cyst size (5×3 cm) and no pain. This case illustrates successful percutaneous transhepatic and translumbar sclerotherapy for retrocardiac and retrocrural thoracic duct cysts, which are very difficult to remove surgically.
Perception of Interventional Radiology among Jazan Medical Students: Assessment of Knowledge and Career Intentions
Authors: Bahkali Salha Al , Harbi Ali Al , Kamili Fatimah , Rashidi Ibrahim Al 
Published: June 2021

Abstract
Context Lack of awareness among the students in the medical field is the greatest challenge to overcome in the emergence of contemporary interventional radiology (IR).
Objectives We aimed to conduct a survey among medical students of Jazan University to explore their knowledge about IR, interest in IR as a future career, and preferred methods of training in IR.
Materials and Methods This was a cross-sectional, self-directed questionnaire study. The target population was all medical students at Jazan University. Surveys were sent to 600 students. The questionnaire consisted of 11 closed and open-ended questions.
Statistical Analysis We calculated the size of the sample using the Raosoft Sample Size Calculator Web site. Data analysis was performed using SPSS statistics.
Results A total of 270 students responded (45%); more than half of the respondents (58.5%) were in the preclinical stage, while the rest were in the clinical stage. About 62.5% of clinical students and 66.4% preclinical students reported that their perception regarding the terminology of IR was good or excellent. Regarding the identification of interventional radiologists, 50.9% from the clinical students thought them to be radiologists and 50% from preclinical students also identified them as such.About 29.5% from the clinical students and 27.8% from the preclinical students thought them special surgeons, and 31.3% clinical students compared with 30.4% preclinical students believed they are vascular surgeons working with X-rays. About 19.6% clinical students compared with 17.7% preclinical students said they are general surgeons working with X-rays, and 48.2% clinical students compared with 45.6% preclinical students said they are special radiologists who work with percutaneous techniques. There was a significant difference (p = 0.041) in the responses between preclinical and clinical students regarding knowledge about what this medical specialty does. About 60.8% of clinical students reported that their knowledge and information regarding IR are efficient in comparison to 39.2% of preclinical students.
Conclusion This study demonstrated that the basic knowledge among Jazan medical students is poor. About half of the respondents were clinical students who understood the radiology specialty, compared with one-third of preclinical students. This could impact the student’s decision toward IR as a future career.
The epistemic foundations of injustice: lessons from the Young Marx
Authors: Casuso Gianfranco 
Published: June 2021

AbstractThis article intends to show to what extent the early Marxian categories of alienation, ideology and proletariat can serve to better understand current forms of epistemic injustice, as well as, conversely, how the latter can illuminate some unclear aspects of such concepts. In the first part, it will be explained the extent to which Marx’s concept of alienation accounts for the experience of an individual in a world to whose norms she is subject, but which she cannot recognise as her own. It will be shown that Marx finds the answer in a form of emancipatory praxis linked to a transformative appropriation of social reality. In order to deepen the understanding of this idea of emancipation, the second part will analyse the Marxian concept of the proletariat. It will be argued that taking up some considerations about the Hegelian figure of the rabble, Marx distinguishes a “liberal” from a “human” form of emancipation. In the third part, a contemporary example will be used to show the usefulness of the young Marx’s analyses concerning this dimension of emancipation struggles. In the fourth part, these ideas will be developed further through the concept of epistemic injustice, which has gained great importance in the recent studies that Critical Theory carries out of the different socio-epistemic blocks of an ideological nature that prevent articulating, communicating and overcoming negative experiences that hinder individual self-realisation. In this sense, it will be shown the importance of the Marxian categories of alienation and ideology to theoretically address current forms of epistemic injustice, and, in relation to this, it will be explained the transformative and constitutive function of the excluded in the creation of new sectors of reality through which their demands can be met.
Periodic bouncing of a plasmonic bubble in a binary liquid by competing solutal and thermal Marangoni forces
Authors: Zeng Binglin , Chong Kai Leong , Wang Yuliang , Diddens Christian , Li Xiaolai , Detert Marvin , Zandvliet Harold J. W. , Lohse Detlef 
Published: June 2021

Significance
Plasmonic bubbles are relevant in biomedical diagnosis and therapy, catalysis, and micro- and nanomanipulation. Hitherto, their behavior has mainly been analyzed in pure liquids. However, in general, these applications of plasmonic bubbles take place in binary or multicomponent liquids. Here we show that plasmonic bubbles in a binary liquid display surprising phenomena, resulting from the emerging complicated physicochemical hydrodynamics of a vapor bubble in such binary liquids. Depending on the application, these phenomena can be either a benefit or a hindrance. Our results are also relevant for other bubble nucleation processes in multicomponent liquids, such as boiling, electrolysis, or catalysis.
Final report on APMP comparison in humidity APMP.T−K8: Dew point temperature +30 °C to +95 °C
Authors: Abe H , Kitano H , Lovell-Smith J , Achmadi A , Cheung C P , Choi B I , Hussain F , Jahan F , Norranim U , Sindhu A , Tsai S-F , Wang L 
Published: June 2021

Main text
A key comparison in dew-point temperature in the range of +30 °C to +95 °C was carried out among the national standards held by NMIJ (pilot), MSL (coordinator), RCM-LIPI/SNSU-BSN, SCL, KRISS, NMIM, NMIA, NIMT, CMS/ITRI, and NMC, A*STAR. The purpose of the comparison was to establish the degree of equivalence between realizations of local scales of dew point temperature of humid gas among the participating national institutes. Although the comparison schedule was considerably delayed, no significant drift of the transfer standard was observed over the whole period of the comparison. The result of a chi-squared test demonstrated that the comparison was effective, and the results obtained in the comparison can be used as reliable supporting evidence for CMCs that each participant claims.
To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.
The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
In the realm of the Hubble tension—a review of solutions
*
Authors: Di Valentino Eleonora , Mena Olga , Pan Supriya , Visinelli Luca , Yang Weiqiang , Melchiorri Alessandro , Mota David F , Riess Adam G , Silk Joseph 
Published: June 2021

Abstract
The simplest ΛCDM model provides a good fit to a large span of cosmological data but harbors large areas of phenomenology and ignorance. With the improvement of the number and the accuracy of observations, discrepancies among key cosmological parameters of the model have emerged. The most statistically significant tension is the 4σ to 6σ disagreement between predictions of the Hubble constant, H
0, made by the early time probes in concert with the ‘vanilla’ ΛCDM cosmological model, and a number of late time, model-independent determinations of H
0 from local measurements of distances and redshifts. The high precision and consistency of the data at both ends present strong challenges to the possible solution space and demands a hypothesis with enough rigor to explain multiple observations—whether these invoke new physics, unexpected large-scale structures or multiple, unrelated errors. A thorough review of the problem including a discussion of recent Hubble constant estimates and a summary of the proposed theoretical solutions is presented here. We include more than 1000 references, indicating that the interest in this area has grown considerably just during the last few years. We classify the many proposals to resolve the tension in these categories: early dark energy, late dark energy, dark energy models with 6 degrees of freedom and their extensions, models with extra relativistic degrees of freedom, models with extra interactions, unified cosmologies, modified gravity, inflationary models, modified recombination history, physics of the critical phenomena, and alternative proposals. Some are formally successful, improving the fit to the data in light of their additional degrees of freedom, restoring agreement within 1–2σ between Planck 2018, using the cosmic microwave background power spectra data, baryon acoustic oscillations, Pantheon SN data, and R20, the latest SH0ES Team Riess, et al (2021 Astrophys. J.
908 L6) measurement of the Hubble constant (H
0 = 73.2 ± 1.3 km s−1 Mpc−1 at 68% confidence level). However, there are many more unsuccessful models which leave the discrepancy well above the 3σ disagreement level. In many cases, reduced tension comes not simply from a change in the value of H
0 but also due to an increase in its uncertainty due to degeneracy with additional physics, complicating the picture and pointing to the need for additional probes. While no specific proposal makes a strong case for being highly likely or far better than all others, solutions involving early or dynamical dark energy, neutrino interactions, interacting cosmologies, primordial magnetic fields, and modified gravity provide the best options until a better alternative comes along.
Binary acoustic trapping in a glass capillary
Authors: Fornell Anna , Baasch Thierry , Johannesson Carl , Nilsson Johan , Tenje Maria 
Published: June 2021

Abstract
Acoustic trapping is a useful method for handling biological samples in microfluidic systems. The aim of this work is twofold: first to investigate the physics behind acoustic trapping in a glass capillary and secondly to perform binary acoustic trapping. The latter is achieved by increasing the density of the fluid in the trapping channel. The trapping device consisted of a glass capillary with a rectangular inner cross-section (height 200 µm × width 2000 µm) equipped with a small piezoelectric transducer. The piezoelectric transducer was actuated at 4 MHz to generate a localised half-wavelength acoustic standing-wave-field in the capillary, comprising of a pressure field and a velocity field. Under acoustic actuation, only particles with higher density than the fluid, i.e. having a positive dipole scattering coefficient, were trapped in the flow direction. The numerical and analytical modelling of the system show that the trapping force which retains the particles against the flow depends only on the dipole scattering coefficient in the pressure nodal plane of the acoustic field. The analytical model also reveals that the retention force is proportional to the dipole scattering coefficient, which agrees with our experimental findings. Next, we showed that in a mixture of melamine particles and polystyrene particles in a high-density fluid it is possible to selectively trap melamine particles, since melamine particles have higher density than polystyrene particles.
A temperature gradient evaluation method for determining temperature dependent thermal conductivities
Authors: Wilhelmy Sönke , Zimare Anton , Lippmann Stephanie , Rettenmayr Markus 
Published: June 2021

Abstract
Details of an experimental set-up and an evaluation method for determining temperature dependent thermal conductivities from one-dimensional steady-state temperature distributions are presented. The method is validated by obtaining continuous values for the thermal conductivities of pure Ni in the temperature range between 440 K and 740 K, brass (Cu-30Zn) in the temperature range between 350 K and 650 K and a titanium aluminide (TiAl-TNM) in the temperature range between 400 K and 700 K. The results are in agreement with available literature data. The reported scatter in the literature on conductivities is caused by microstructural or/and compositional differences, which highlights the necessity for swift and accurate experimental determination of thermal properties. For this, the proposed temperature gradient evaluation method is especially suited as it allows the direct determination of thermal properties within large temperature intervals using only a single experimental run. The experimental effort for a comprehensive study of a material is thus drastically reduced as compared to the conventional method of determining thermal conductivity from measured thermal diffusivities and heat capacities. The experimental set-up additionally allows the independent determination of thermal diffusivity as function of temperature. No prior knowledge of any material properties of a given sample is necessary.
Cell spreading behaviors on hybrid nanopillar and nanohole arrays
Authors: Wu Xiaomin , Li Li , Wang Lu , Lei Zecheng , Yang Fan , Liu Ri , Wang Ying , Peng Kuiqing , Wang Zuobin 
Published: June 2021

Abstract
Although nanopillars (NPs) provide a promising tool for capturing tumor cells, the effect of mixing NPs with other nanopatterns on cell behavior remains to be further studied. In this paper, a method of fabricating silicon nanoscale topographies by combining laser interference lithography with metal assisted chemical etching was introduced to investigate the behaviors and pseudopodia of A549 cells on the topologies. It was found that cells had a limited manner in spreading with small cell areas on the silicon nanopillar (SiNP) arrays, but a good manner in spreading with large cell areas on the silicon nanohole (SiNH) arrays. When on the hybrid SiNP/SiNH arrays, cells had medium cell areas and they arranged orderly along the boundaries of SiNPs and SiNHs, as well as 80% of cells displayed a preference for SiNPs over SiNHs. Furthermore, the lamellipodia and filopodia are dominant in the hybrid SiNP/SiNH and SiNP arrays, respectively, both of them are dominant in the SiNH arrays. In addition, the atomic force acoustic microscopy was also employed to detect the subsurface features of samples. The results suggest that the hybrid SiNP/SiNH arrays have a targeted trap and elongation effect on cells. The findings provide a promising method in designing hybrid nanostructures for efficient tumor cell traps, as well as regulating the cell behaviors and pseudopodia.
Self-Assembly of DNA molecules in magnetic Fields
Authors: Gao Mingyan , Hu Jing , Wang Jianfei , Liu Mengnan , Zhu Xiaona , Saeed Sadaf , Hu Cuihua , Song Zhengxun , Xu Hongmei , Wang Zuobin 
Published: June 2021

Abstract
In this work, a rich variety of self-assembled DNA patterns were obtained in the magnetic field. Herein, atomic force microscopy (AFM) was utilized to investigate the effects of the concentration of DNA solution, intensity and direction of magnetic field and modification of mica surface by different cations on the self-assembly of DNA molecules. It was found that owning to the change of the DNA concentration, even under the same magnetic field, the DNA self-assembly results were different. The in situ test results showed that the DNA self-assembly in an magnetic field was more likely to occur in liquid phase than in gas phase. In addition, whether in a horizontal or vertical magnetic field, a single stretched dsDNA was obtained in a certain DNA concentration and magnetic field intensity. Besides, the modification of cations on the mica surface significantly increased the force between the DNA molecules and mica surface, and further changed the self-assembly of DNA molecules under the action of magnetic field.
Using smartphone cameras and ambient light sensors in distance learning: the attenuation law as experimental determination of gamma correction
Authors: Onorato Pasquale , Rosi Tommaso , Tufino Eugenio , Caprara Caterina , Malgieri Massimiliano 
Published: June 2021

Abstract
In times of the explosion of distance learning, because of emergency due to the pandemic, smartphone sensors and cameras are extremely valuable for teachers as they allow students to perform significant experimental activities in their own homes. The open-source software Tracker can be used in combination with the smartphone camera to perform measurements not only of mechanics activities, but also of optics. In the latter case, it is not always easy for students to understand how the pixel brightness which can be inferred from the taken photos are related to actual physical light intensity. In this paper we present a simple experiment to verify the exponential decay in the intensity of light going through successive sheets of a material (the Lambert law) with two different methods, i.e. using either the smartphone light sensor or the smartphone camera and Tracker. Besides its theoretical significance, the experiment constitutes a useful tool for calibrating the camera/Tracker combination to use it for different experiments.