bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solar activity and responses observed in Balmer lines
Authors: Marchenko S. , Criscuoli S. , DeLand M. T. , Choudhary D. P. , Kopp G. 
Published: December 2020

Context. Many stars show Sun-like magnetic activity cycles, which are frequently observed by tracking changes in the chromospherically sensitive CaII H&K doublet. However, relationships between the line profile changes related to the magnetic activity seen in strong spectral transitions in other portions of a stellar spectrum are yet to be understood.
Aims. We follow variability patterns in various solar lines in order to relate them to the emergence, passage, and decay of active solar regions.
Methods. The line activity indices (core-to-wing ratio) for the upper Balmer lines – Hβ, Hγ, and Hδ – are constructed from the near-daily solar measurements acquired by the Ozone Monitoring Instrument and the TROPOspheric Monitoring Instrument.
Results. On solar rotation timescales, the upper Balmer line activity indices closely follow variations in the total solar irradiance, r ∼ −(0.6 − 0.7), and thus frequently deviate from the behavior of the line activity indices that track chromospheric activity levels (e.g., the CH 430 nm band used in this study), specifically during passages of big sunspot groups.
Pebbles in an embedded protostellar disk: the case of CB 26
Authors: Zhang Chuan-Peng , Launhardt Ralf , Liu Yao , Tobin John J. , Henning Thomas 
Published: December 2020

Context.Planetary cores are thought to form in proto-planetary disks via the growth of dusty solid material. However, it is unclear how early this process begins.Aims.We study the physical structure and grain growth in the edge-on disk that surrounds the ≈1 Myr old low-mass (≈0.55M⊙) protostar embedded in the Bok globule CB26 to examine how much grain growth has already occurred in the protostellar phase.Methods.We combine the spectral energy distribution between 0.9μm and 6.4 cm with high-angular-resolution continuum maps at 1.3, 2.9, and 8.1 mm and use the radiative transfer codeRADMC-3Dto conduct a detailed modeling of the dust emission from the disk and envelope of CB 26.Results.Given the presence of a central disk cavity, we infer inner and outer disk radii of 16−8+37and 172 ± 22 au, respectively. The total gas mass in the disk is 7.610−2M⊙, which amounts to ≈14% of the mass of the central star. The inner disk contains a compact free-free emission region, which could be related to either a jet or a photoevaporation region. The thermal dust emission from the outer disk is optically thin at millimeter wavelengths, while the emission from the inner disk midplane is moderately optically thick. Our best-fit radiative transfer models indicate that the dust grains in the disk have already grown to pebbles with diameters on the order of 10 cm in size. Residual 8.1 mm emission suggests the presence of even larger particles in the inner disk. For the optically thin millimeter dust emission from the outer disk, we derive a mean opacity slope ofβmm≈ 0.7 ± 0.4, which is consistent with the presence of large dust grains.Conclusions.The presence of centimeter-sized bodies in the CB 26 disk indicates that solids are already growing rapidly during the first million years in a protostellar disk. It is thus possible that Class II disks are already seeded with large particles and may even contain planetesimals.
CT Features of COVID-19 Pneumonia Differ Depending on the Severity and Duration of Disease
Authors: Schaible Jan , Meiler Stefanie , Poschenrieder Florian , Scharf Gregor , Zeman Florian , Knobloch Charlotte , Rennert Janine , Pregler Benedikt , Kleine Henning , Menzel Cynthia , Stroszczynski Christian , Zorger Niels , Hamer Okka W 
Published: December 2020

Background CT is important in the care of patients with COVID-19 pneumonia. However, CT morphology can change significantly over the course of the disease. To evaluate the CT morphology of RT-PCR-proven COVID-19 pneumonia in a German cohort with special emphasis on identification of potential differences of CT features depending on duration and severity of disease.
Method All patients with RT-PCR-proven COVID-19 pneumonia and chest CT performed between March 1 and April 15, 2020 were retrospectively identified. The CT scans were evaluated regarding the presence of different CT features (e. g. ground glass opacity, consolidation, crazy paving, vessel enlargement, shape, and margin of opacifications), distribution of lesions in the lung and extent of parenchymal involvement. For subgroup analyses the patients were divided according to the percentage of parenchymal opacification (0–33 %, 34–66 %, 67–100 %) and according to time interval between symptom onset and CT date (0–5 d, 6–10 d, 11–15 d, > 15 d). Differences in CT features and distribution between subgroups were tested using the Mantel-Haenszel Chi Squared for trend.
Results The frequency of CT features (ground glass opacity, consolidation, crazy paving, bronchial dilatation, vessel enlargement, lymphadenopathy, pleural effusion) as well as pattern of parenchymal involvement differed significantly depending on the duration of disease and extent of parenchymal involvement. The early phase of disease was characterized by GGO and to a lesser extent consolidation. The opacifications tended to be round and to some extent with sharp margins and a geographic configuration. The vessels within/around the opacifications were frequently dilated. Later on, the frequency of consolidation and especially crazy paving increased, and the round/geographic shape faded. After day 15, bronchial dilatation occurred, and lymphadenopathy and pleural effusion were seen more frequently than before.
Conclusion The prevalence of CT features varied considerably during the course of disease and depending on the severity of parenchymal involvement. Radiologists should take into account the time interval between symptom onset and date of CT and the severity of disease when discussing the likelihood of COVID-19 pneumonia based on CT morphology.
Key Points:
Citation Format
Heroinintoxikationen: Risikofaktoren zur Notfallanamnese aus Expertensicht
Authors: Schneider Sven , Richter Christian , Niethammer Rainer , Beisel Larissa 
Published: December 2020

Zusammenfassung
Ziel der Studie Heroinintoxikationen nehmen in der Notfallmedizin seit Jahren den 1. Platz unter allen Drogennotfällen ein.
Methodik Zwischen April und Oktober 2019 wurden bundesweit 107 ExpertInnen aus 36 Einrichtungen in 23 Städten mit beruflichen Erfahrungen mit Heroinintoxikationen im Rahmen eines interdisziplinären und multiprofessionellen Rankingverfahrens zu den wichtigsten Risikofaktoren solcher Drogennotfälle befragt.
Ergebnisse Im Rahmen der Notfallanamnese sollten aus Expertensicht vor allem folgende Risikofaktoren berücksichtigt werden: Wiederaufnahme des Konsums nach längerer Abstinenz oder reduzierter Heroinaufnahme, Mischintoxikationen respektive Beikonsum von Benzodiazepinen, Alkohol, Pregabalin und/oder illegalen Drogen, Applikation, Menge und Reinheit des Heroins sowie ein akutes soziales Stressereignis.
Schlussfolgerung Unser Beitrag gibt Hinweise, welche Rahmenbedingungen der Notarzt im Rahmen der Notfallanamnese vor allem erfragen und dokumentieren sollte.
Late-Stage Transformation of Carboxylic Acids to N-Trifluoroethyl­imides with Trifluoromethyl Diazomethane
Authors: Hu Xiang-Guo , Qiu Xiao-Feng , Liu De-Yong , Zhang Wen-Feng 
Published: December 2020

AbstractWe report the first systematic evaluation of the reaction of trifluoromethyl diazomethane (2,2,2-trifluorodiazoethane, CF3CHN2) with drug-like molecules. We found our previous copper-catalyzed transformation of carboxylic acids to the corresponding N-trifluoro­ethylimides with CF3CHN2 and acetonitrile is well-suited for the late-stage modification of drug and drug-like acids. A procedure that enables the use of solid nitriles and nitriles with high boiling points as viable substrates is also disclosed.
General elephants for threefold extremal contractions with one-dimensional fibres: exceptional case
Authors: Mori S. , Prokhorov Yu. G. 
Published: December 2020

Abstract
Let

be a germ of a threefold

with terminal singularities along a connected reduced complete curve

with a contraction

such that

and

is

-ample. Assume that each irreducible component of

contains at most one point of index

. We prove that a general member

is a normal surface with Du Val singularities.
Bibliography: 16 titles.
Uniform convergence criterion for non-harmonic sine series
Authors: Oganesyan K. A. 
Published: December 2020

Abstract
We show that for a nonnegative monotonic sequence

the condition

is sufficient for the series

to converge uniformly on any bounded set for

, and for any odd

it is sufficient for it to converge uniformly on the whole of

. Moreover, the latter assertion still holds if we replace

by any polynomial in odd powers with rational coefficients. On the other hand, in the case of even

it is necessary that

for the above series to converge at the point

or at

. As a consequence, we obtain uniform convergence criteria. Furthermore, the results for natural numbers

remain true for sequences in the more general class

.
Bibliography: 17 titles.
Der Tod bei Plotin und Plotins Tod in derVita Plotinides Porphyrios
Authors: Hammann Christoph 
Published: December 2020

AbstractDieser Beitrag geht der Frage nach, ob zwischen den Schriften Plotins und derVita Plotinides Porphyrios im Hinblick auf das Verständnis des Todes und die Annahme der Unsterblichkeit der Seele eine Kohärenz zu erkennen ist. Dafür wird im ersten Teil zunächst anhand derEnneadengezeigt, was Plotin für sterblich erachtet, wie Plotin den konkreten Vorgang des Sterbens versteht, welche Hintergründe Plotin für Ewigkeit und für Sterblichkeit annimmt, welche Konsequenzen die Bindung der Seele an den Körper nach Plotin für die Seele hat und wie sich aus Plotins Sicht die Trennung der Seele vom Körper auf das Leben der Seele auswirkt. Im zweiten Teil wird anhand derVita Plotinigezeigt, dass die Darstellung, die Porphyrios von Plotins Tod und der Existenz von Plotins Seele nach dem Tod bietet, mit Plotins Konzeption im Wesentlichen übereinstimmt.
Bontia daphnoides (white alling).
Authors: Vélez-Gavilán Jeanine 
Published: December 2020

Abstract

Bontia daphnoides is a shrub species native to the Caribbean and South America, which has been introduced to Cuba and the USA. B. daphnoides is considered invasive in Cuba, but Oviedo Prieto et al. (2006) provide conflicting information about the species occurrence in the country. They report it as only rarely seen in mangroves in the west part of the country, but later in the same document they list it as invasive in that same area. More information is needed to determine the invasiveness of this species in Cuba. The species is not considered invasive in the two states where it has been introduced in the USA (Florida and Hawaii).
Bixa orellana (annatto).
Authors: Ventosa Eduardo 
Published: December 2020

Abstract

B. orellana is a shrub or small tree which was one of the first American plants to be introduced into southern Asia and tropical Africa and soon became naturalized in these areas and in the East Indies (Morton, 1960). It is recognized as an exotic species in the Lesser and Greater Antilles. In Puerto Rico and the Virgin Islands it is considered to be naturalized (Acevedo-Rodríguez and Strong 2012). It is listed as invasive principally on Pacific islands, although a risk assessment considers it as low risk in the region (PIER, 2015).
Supplementary comparison EURAMET.EM-S42, comparison of lightning impulse (LI) reference measuring systems
Authors: Hällström J , Elg A-P , Havunen J , Garnacho F 
Published: December 2020

Main text
In 2016 the Consultative Committee for Electricity and Magnetism (CCEM) commissioned a supplementary comparison EURAMET.EM-S42 of Lightning Impulse (LI) measurement systems. This comparison was piloted by RISE (Sweden, formerly SP), and it was supported by VTT MIKES (Finland) and FFII LCOE (Spain). Eleven National Metrology Institutes (NMI) and two Designated Institutes (DI) from four Regional Metrology Organizations, EURAMET, COOMET, APMP and SIM, took part in the comparison.
A commercial travelling measuring system (TRMS) for Lightning Impulse (LI) measurement was adopted for the comparison. The TRMS consisted of a 700 kV resistive voltage divider and a transient recorder with computer. The TRMS was calibrated by the pilot lab in November 2016 before start of the comparison, and the first circulation was between five EURAMET NMI/DIs. After an intermediate calibration by the pilot lab in July 2017, the TRMS was circulated between seven NMI/DIs in the other regional organisations. On the return of the TRMS in March 2019 a final calibration was made by the pilot lab.
The measured parameters are defined in IEC60060-1. Test voltage value (U
t), front time (T
1), time to half value (T
2) and relative overshoot (β') were measured for full impulses; and extreme value (U
e) and time to chopping (T
c) for front chopped waveform. The test voltage value ranged from -700 kV to 700 kV with two full and one chopped impulse waveform. A set of preferred voltage levels and waveforms was defined. The obtained expanded uncertainties (k = 2) of the comparison reference values (CRV) were: <0.3% for U
t, <1.3% for T
1, <1.0% for T
2, <0.4% for β', <0.6% for U
e and <1.4% for T
c.
The transfer reference measuring system of the previous LI comparison (EU-SMT4-CT98-2270), arranged between 1999 and 2002, is linked to this comparison. The link is established by comparing VTT MIKES system used 20 years ago with that used in this comparison.
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 kcdb.bipm.org/.
The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Update of the BIPM comparison BIPM.RI(II)-K1.Ag-110m of activity measurements of the radionuclide 110mAg to include the 2015 result of the PTB (Germany)
Authors: Michotte C , Courte S , Nonis M , Coulon R , Judge S , Ratel G , Kossert K , Nähle O 
Published: December 2020

Main text
Since 1983, 6 laboratories have submitted 7 samples of 110mAg to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ag-110m. Recently, the PTB (Germany) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given.
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 kcdb.bipm.org/.
The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Controllable photon extraction based on a single-photon Raman interaction
Authors: Hu Yu , He Shu , Zhang Yuanwei , Yuan Haidong , Liu W M , Yan Cong-Hua 
Published: December 2020

Abstract
A target whispering-gallery-mode microresonator (WGMM) directly coupled to a waveguide with an auxiliary side-coupled WGMM is proposed to deterministically extract both the resonant and non-resonant single incident photons from a waveguide. Based on the single-photon Raman interaction (SPRINT) between an Λ-type three-level atom and the target WGMM, a full quantum theory in real space is adopted to calculate the extraction efficiencies at the single-photon level. The results show that the extraction efficiencies can be significantly improved by appropriately tuning the frequencies of the auxiliary WGMM and the coupling strength between the two WGMMs, even when the atom and WGMMs have dissipations. Since mode redistribution is only externally imposed on the auxiliary WGMM, the population and phase of the atom are not directly affected. The nonlocal control, which ensures that the SPRINT takes place, results in high extraction efficiencies. We also find that the transmission probabilities of both the resonant and non-resonant incident photons can be controlled in a range from 0 to 100%, so that the proposed double-WGMM system has the potential to be used as a single-photon switch.
Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N2 and their mixtures
Authors: Albert A , Bošnjaković D , Dujko S , Donkó Z 
Published: December 2020

Abstract
The relaxation of the distribution function of the electrons drifting under the influence of a homogeneous electric field in noble gases is known to take place over an extended spatial domain at ‘intermediate’ values of the reduced electric field, E/N. We investigate the transport of electrons in Ar and N2 gases, as well as in their mixtures at such E/N values (∼10–40 Td). After discussing briefly the basic scenario of relaxation in a homogeneous electric field, the major part of work concentrates on the properties of transport in an electric field that is spatially modulated within a finite region that obeys periodic boundaries. The spatial distribution of the mean velocity, the mean energy, and the density of the electrons, the importance of the excitation channels, as well as the electron energy distribution function are obtained from Monte Carlo simulations for various lengths of the computational domain, at different mean values and degrees of modulation of the reduced electric field. At low modulations, the spatial profiles of the mean velocity and mean energy are nearly harmonic, however their phases with respect to the electric field perturbation exhibit a complex behaviour as a function of the parameters. With increasing modulation, an increasing higher harmonic content of these profiles is observed and at high modulations where an electric field reversal occurs, we observe trapping of a significant population of the electrons. The effect of mixing a molecular gas, N2, to Ar on the transport characteristics is also examined. Transition to local transport at high N2 admixture concentrations and long spatial domains is observed.
Large power dissipation of hot Dirac fermions in twisted bilayer graphene
Authors: Kubakaddi S S 
Published: December 2020

Abstract
We have carried out a theoretical investigation of hot electron power loss P, involving electron–acoustic phonon interaction, as a function of twist angle θ, electron temperature T
e and electron density n
s in twisted bilayer graphene. It is found that as θ decreases closer to magic angle θ
m, P enhances strongly and θ acts as an important tunable parameter, apart from T
e and n
s. In the range of T
e = 1–50 K, this enhancement is ∼250–450 times the P in monolayer graphene (MLG), which is manifestation of the great suppression of Fermi velocity v
F
* of electrons in moiré flat band. As θ increases away from θ
m, the impact of θ on P decreases, tending to that of MLG at θ ∼ 3°. In the Bloch–Grüneisen (BG) regime, P ∼ T
e
4, n
s
−1/2 and v
F
*−2. In the higher temperature region (∼10–50 K), P ∼ T
e

δ
, with δ ∼ 2.0, and the behavior is still super linear in T
e, unlike the phonon limited linear-in-T (lattice temperature) resistivity ρ
p. P is weakly, decreasing (increasing) with increasing n
s at lower (higher) T
e, as found in MLG. The energy relaxation time τ
e is also discussed as a function of θ and T
e. Expressing the power loss P = F
e(T
e) − F
e(T), in the BG regime, we have obtained a simple and useful relation F
e(T)μ
p(T) = (ev
s
2/2) i.e. F
e(T) = (n
s
e
2
v
s
2/2)ρ
p, where μ
p is the acoustic phonon limited mobility and v
s is the acoustic phonon velocity. The ρ
p estimated from this relation using our calculated F
e(T) is nearly agreeing with the ρ
p of Wu et al (2019 Phys. Rev. B
99 165112).
Parameter identification of micron-sized freestanding stretchable electronic interconnects using integrated digital height correlation
Authors: Kleinendorst S M , Shafqat S , Geers M G D , Hoefnagels J P M 
Published: December 2020

Abstract
For the development of reliable stretchable electronic systems, it is essential to comprehend and predict their mechanical behavior. It is important to test and analyze original as-processed samples, as opposed to standard tests on bulk material. Dedicated analysis methods are necessary for obtaining the material properties from the tests, as complex 3D deformations complicate the use of existing methods. This paper presents an integrated digital height correlation (IDHC) method for the mechanical characterization of a recently developed ultra-stretchable freestanding interconnect. Height maps from an out-of-plane loading experiment are correlated to a numerical model, with the aim to identify the material parameters in the plastic regime. The IDHC method is tested on a virtual test case, where it is shown that the algorithm converges for the considered three plasticity parameters. For the real experiment, simultaneous correlation of all three parameters is not possible due to an inherently flat residual landscape with many local minima. However, the initial yield strength and hardening exponent were still identified and estimated at 225–300 MPa and 0.15–0.2 respectively. Despite the moderate accuracy of the identification, the potency of the IDHC method for this extremely challenging case of micron-sized delicate freestanding stretchable electronic interconnects is demonstrated.
Development of a coupled simulation toolkit for computational radiation biology based on Geant4 and CompuCell3D
Authors: Liu Ruirui , Higley Kathryn A , Swat Maciej H , Chaplain Mark A J , Powathil Gibin G , Glazier James A 
Published: December 2020

Abstract
Understanding and designing clinical radiation therapy is one of the most important areas of state-of-the-art oncological treatment regimens. Decades of research have gone into developing sophisticated treatment devices and optimization protocols for schedules and dosages. In this paper, we presented a comprehensive computational platform that facilitates building of the sophisticated multi-cell-based model of how radiation affects the biology of living tissue. We designed and implemented a coupled simulation method, including a radiation transport model, and a cell biology model, to simulate the tumor response after irradiation. The radiation transport simulation was implemented through Geant4 which is an open-source Monte Carlo simulation platform that provides many flexibilities for users, as well as low energy DNA damage simulation physics, Geant4-DNA. The cell biology simulation was implemented using CompuCell3D (CC3D) which is a cell biology simulation platform. In order to couple Geant4 solver with CC3D, we developed a ‘bridging’ module, RADCELL, that extracts tumor cellular geometry of the CC3D simulation (including specification of the individual cells) and ported it to the Geant4 for radiation transport simulation. The cell dose and cell DNA damage distribution in multicellular system were obtained using Geant4. The tumor response was simulated using cell-based tissue models based on CC3D, and the cell dose and cell DNA damage information were fed back through RADCELL to CC3D for updating the cell properties. By merging two powerful and widely used modeling platforms, CC3D and Geant4, we delivered a novel tool that can give us the ability to simulate the dynamics of biological tissue in the presence of ionizing radiation, which provides a framework for quantifying the biological consequences of radiation therapy. In this introductory methods paper, we described our modeling platform in detail and showed how it can be applied to study the application of radiotherapy to a vascularized tumor.