bluuebunny/crossref_metadata_2025_split huggingface dataset:
A model for the hydrogenation and charge states of fullerene C60
Authors: Abbink Daphne , Foing Bernard , Ehrenfreund Pascale 
Published: January 2024

Context. The diffuse interstellar bands (DIBs) are a set of ∼600 absorption features at optical and near-infrared wavelengths that are found in the interstellar medium in the Milky Way and other galaxies. They remain mostly unidentified and represent the greatest unsolved mystery in astronomical spectroscopy of the past 100 years. Many studies indicate that the carrier molecules are likely carbonaceous molecules, such as polycyclic aromatic hydrocarbons (PAHs) or fullerenes, a theory that is supported by the identifications of five DIBs in the near-infrared attributed to C60+.
Aims. This work aims to narrow down which compounds related to C60 could be promising DIB carrier candidates. We did so by conducting a theoretical study of its hydrogenation and charge balance.
Methods. We defined a system of relevant reactions, and for each reaction we computed or derived from the literature a reaction rate coefficient. Assuming a steady state, we then computed a distribution of relative abundances in each hydrogenation and charge state.
Results. From the model outcomes, we expect the most abundant hydrogenated buckminsterfullerene compound in the diffuse interstellar medium to be C60H+.
Eruptive events with exceptionally bright emission in H I Ly-α observed by the Metis coronagraph
Authors: Russano G. , Andretta V. , De Leo Y. , Teriaca L. , Uslenghi M. , Giordano S. , Telloni D. , Heinzel P. , Jejčič S. , Abbo L. , Bemporad A. , Burtovoi A. , Capuano G. E. , Frassati F. , Guglielmino S. L. , Jerse G. , Landini F. , Liberatore A. , Nicolini G. , Pancrazzi M. , Romano P. , Sasso C. , Susino R. , Zangrilli L. , Da Deppo V. , Fineschi S. , Grimani C. , Moses J. D. , Naletto G. , Romoli M. , Spadaro D. , Stangalini M. 
Published: January 2024

Context. Ultraviolet (UV) emission from coronal mass ejections can provide information on the evolution of plasma dynamics, temperature, and elemental composition, as demonstrated by the UV Coronagraph Spectrometer (UVCS) on board the SOlar and Heliospheric Observatory (SOHO). Metis, the coronagraph on board Solar Orbiter, provides for the first time coronagraphic imaging in the UV H I Ly-α line and, simultaneously, in polarized visible light, thus providing a host of information on the properties of coronal mass ejections and solar eruptions such as their overall dynamics, time evolution, mass content, and outflow propagation velocity in the expanding corona.
Aims. For this work, we analyzed six coronal mass ejections observed by Metis between April and October 2021, which are characterized by a very strong H I Ly-α emission. We studied in particular the morphology, kinematics, and the temporal and radial evolution of the emission of such events, focusing on the brightest UV features.
Methods. The kinematics of the eruptive events under consideration were studied by determining the height-time profiles of the brightest parts on the Metis plane of the sky. Furthermore, the 3D positions in the heliosphere of the coronal mass ejections were determined by employing co-temporal images, when available, from two other coronagraphs: LASCO/C2 on board SOHO, and COR2 on board STEREO-A. In three cases, the most likely source region on the solar surface could be identified. Finally, the radiometrically calibrated Metis images of the bright UV features were analyzed to provide estimates of their volume and density. From the kinematics and radiometric analysis, we obtained indications of the temperatures of the bright UV cores of these events. These results were then compared with previous studies with the UVCS spectrocoronagraph.
Results. The analysis of these strong UV-emitting features associated with coronal mass ejections demonstrates the capabilities of the current constellation of space coronagraphs, Metis, LASCO/C2, and COR2, in providing a complete characterization of the structure and dynamics of eruptive events in their propagation phase from their inception up to several solar radii. Furthermore, we show how the unique capabilities of the Metis instrument to observe these events in both the H I Ly-α line and polarized VL radiation allow plasma diagnostics on the thermal state of these events.
High-speed stars
Authors: Bonifacio P. , Caffau E. , Monaco L. , Sbordone L. , Spite M. , Mucciarelli A. , François P. , Lombardo L. , Matas Pinto A. d. M. 
Published: January 2024

Context. The data from the Gaia satellite led us to revise our conception of the Galaxy structure and history. Hitherto unknown components have been discovered and a deep re-thinking of what the Galactic halo is in progress.
Aims. We selected from the Gaia catalogue stars with extreme transverse velocities with respect to the Sun (|VT|> 500 km s−1) and observed them with FORS2 at the ESO VLT, to classify them using both their chemical and dynamical properties. Two apparently young stars, identified in Paper I, were observed with UVES.
Methods. We derived abundances for Na, Mg, Ca, Ti, Mn, and Fe, analysing the spectra with MyGIsFOS, while for Ba we used line profile fitting. We computed actions from parallaxes and kinematical data.
Results. The stars span the metallicity range −3.5 ≤ [Fe/H] ≤ −0.5 with ⟨[Fe/H]⟩ = −1.6. Star GHS143 has a total speed of about 1440 km s−1, which is almost three times faster than the local escape velocity of 522 km s−1, strongly implying this star is unbound to the Galaxy. Remarkably, this star is not escaping from the Galaxy, but it is falling into it. Ten stars are apparently young with masses in excess of 1.3 M⊙. Their interpretation as evolved blue stragglers is doubtful. The existence of a young metal-poor population is possible. The two stars observed with UVES show no lithium, suggesting they are blue stragglers. We detected a metal-poor population, confined to the bulge, that we call SpiteF, and argue that it is the result of a recent accretion event. We detect 102 candidates of the Aurora population that should have formed prior to the formation of the disc.
Conclusions. Our sample is non-homogeneous and mainly retrograde. The stars are metal poor, and 23% have [Fe/H] ≤ −2.0. Our selection is efficient at finding very metal-poor stars, but it selects peculiar populations.
Accurate ab initio spectroscopic studies of promising interstellar ethanolamine iminic precursors
Authors: Alberton D. , Inostroza-Pino N. , Fortenberry Ryan C. , Lattanzi V. , Endres C. , Zamponi J. Fuentealba , Caselli P. 
Published: January 2024

Context. The detection of NH2CH2CH2OH (ethanolamine) in molecular cloud G+0.693-0.027 adds an additional player to the pre-biotic molecules discovered so far in the interstellar medium (ISM). As this molecule might be formed through condensed-phase hydrogenation steps, detecting one or more of the molecules involved might help to elucidate the chemical pathway leading to its production.
Aims. The chemical path involves the formation of four chemical species. In this work, we study the energies of the isomers involved, indicate the best candidates for detection purposes, and provide the distortion constants of the most energetically favoured isomers undetected so far.
Methods. We used highly accurate CCSD(T)-F12/cc-pCVTZ-F12 computations to predict the lowest energy isomers as well as their spectroscopic constants, taking corrections for core electron correlation and scalar relativity into account.
Results. We studied 14 isomers. We find that the lowest energy isomer proposed in previous studies is not the actual minimum. We provide a set of rotational and distortion constants of the two new most stable isomers together with their fundamental vibrational frequencies in order to guide the search for these important astrochemical precursors of prebiotic molecules in the ISM.
Effect of nuclear reactions rates and core boundary mixing on the seismology of red clump stars
Authors: Noll Anthony , Basu Sarbani , Hekker Saskia 
Published: January 2024

Context. Modeling of the stars in the red clump (RC), that is, core helium-burning stars that have gone through a He flash, is challenging because of the uncertainties associated with the physical processes in their core and during the helium flash. By probing the internal stellar structure, asteroseismology allows us to constrain the core properties of RC stars and eventually, to improve our understanding of this evolutionary phase.
Aims. We aim to quantify the impact on the seismic properties of the RC stars of the two main core modeling uncertainties: core boundary mixing, and helium-burning nuclear reaction rates.
Methods. Using the MESA stellar evolution code, we computed models with different core boundary mixing as well as different 3α and 12C(α, γ)16O nuclear reaction rates. We investigated the impact of these parameters on the period spacing ΔΠ, which is a probe of the region around the core.
Results. We find that different core boundary mixing schemes yield significantly different period spacings, with differences of 30 s between the maximum ΔΠ value computed with semiconvection and maximal overshoot. We show that an increased rate of 12C(α, γ)16O lengthens the core helium-burning phase, which extends the range of ΔΠ covered by the models during their evolution. This results in a difference of 10 s between the models computed with a nominal rate and a rate multiplied by 2, which exceeds the observational uncertainties. The effect of changing the 3α reaction rate is comparatively small.
Conclusions. The core boundary mixing is the main source of uncertainty in the seismic modeling of RC stars. Moreover, the effect of the 12C(α, γ)16O is non-negligible, even though it is difficult to distinguish from the effect of the mixing. This degeneracy could be seen more frequently in the future in the new seismic data from the PLATO mission and through theoretical constraints from numerical simulations.
Tracing the evolution of short-period binaries with super-synchronous fast rotators
Authors: Britavskiy N. , Renzo M. , Nazé Y. , Rauw G. , Vynatheya P. 
Published: January 2024

Context. The initial distribution of rotational velocities of stars is still poorly known, and how the stellar spin evolves from birth to the various end points of stellar evolution is an actively debated topic. Binary interactions are often invoked to explain the existence of extremely fast-rotating stars (vsin i ≳ 200 km s−1). The primary mechanisms through which binaries can spin up stars are tidal interactions, mass transfer, and possibly mergers. However, fast rotation could also be primordial, that is, a result of the star formation process. To evaluate these scenarios, we investigated in detail the evolution of three known fast-rotating stars in short-period spectroscopic and eclipsing binaries, namely HD 25631, HD 191495, and HD 46485, with primaries of masses of 7, 15, and 24 M⊙, respectively, with companions of ∼1 M⊙ and orbital periods of less than 7 days. These systems belong to a recently identified class of binaries with extreme mass ratios, whose evolutionary origin is still poorly understood.
Aims. We evaluated in detail three scenarios that could explain the fast rotation observed in these binaries: it could be primordial, a product of mass transfer, or the result of a merger within an originally triple system. We also discuss the future evolution of these systems to shed light on the impact of fast rotation on binary products.
Methods. We computed grids of single and binary MESA models varying tidal forces and initial binary architectures to investigate the evolution and reproduce observational properties of these systems. When considering the triple scenario, we determined the region of parameter space compatible with the observed binaries and used a publicly available machine-learning model to determine the dynamical stability of the triple system.
Results. We find that, because of the extreme mass-ratio between binary components, tides have a limited impact, regardless of the prescription used, and that the observed short orbital periods are at odds with post-mass-transfer scenarios. We also find that the overwhelming majority of triple systems compatible with the observed binaries are dynamically unstable and would be disrupted within years of formation, forcing a hypothetical merger to happen so close to a zero-age main-sequence that it could be considered part of the star formation process.
Conclusions. The most likely scenario to form such young, rapidly rotating, and short-period binaries is primordial rotation, implying that the observed binaries are pre-interaction ones. Our simulations further indicate that such systems will subsequently go through a common envelope and likely merge. These binaries show that the initial spin distribution of massive stars can have a wide range of rotational velocities.
Testing pulsation diagnostics in the rapidly oscillating magnetic Ap star γ Equ using near-infrared CRIRES+ observations
Authors: Järvinen S. P. , Hubrig S. , Wolff B. , Kurtz D. W. , Mathys G. , Chojnowski S. D. , Schöller M. , Ilyin I. 
Published: January 2024

Context. Pulsations of rapidly oscillating Ap stars and their interaction with the stellar magnetic field have not been studied in the near-infrared (near-IR) region despite the benefits these observations offer compared to visual wavelengths. The main advantage of the near-IR is the quadratic dependence of the Zeeman effect on the wavelength, as opposed to the linear dependence of the Doppler effect.
Aims. To test pulsation diagnostics of roAp stars in the near-IR, we aim to investigate the pulsation behaviour of one of the brightest magnetic roAp stars, γ Equ, which possesses a strong surface magnetic field of the order of several kilogauss and exhibits magnetically split spectral lines in its spectra.
Methods. Two magnetically split spectral lines belonging to different elements, the triplet Fe I at 1563.63 nm and the pseudo-doublet Ce III at 1629.2 nm, were recorded with CRIRES+ over about one hour in the H band with the aim of understanding the character of the line profile variability and the pulsation behaviour of the magnetic field modulus.
Results. The profile shapes of both studied magnetically split spectral lines vary in a rather complex manner probably due to a significant decrease in the strength of the longitudinal field component and an increase in the strength of the transverse field components over the last decade. A mean magnetic field modulus of 3.9 kG was determined for the Zeeman triplet Fe I at 1563.63 nm, whereas for the pseudo-doublet Ce III at 1629.2 nm we observe a much lower value of only about 2.9 kG. For comparison, a mean field modulus of 3.4kG was determined using the Zeeman doublet Fe II at 6249.25 in optical PEPSI spectra recorded just about two weeks before the CRIRES+ observations. Different effects that may lead to the differences in the field modulus values are discussed. Our measurements of the mean magnetic field modulus using the line profiles recorded in different pulsational phase bins suggest a field modulus variability of 32 G for the Zeeman triplet Fe I at 1563.63 nm and 102 G for the pseudo-doublet Ce III at 1629.2 nm.
Hirnmetastasen
Authors: Schulz Christian , Proescholdt Martin , Schmidt Nils Ole , Steger Felix , Heudobler Daniel 
Published: January 2024

ZusammenfassungZerebrale Metastasen bei Patienten mit Lungenkarzinom im Stadium der Metastasierung finden sich bereits bei mehr als 30% Patienten zum Zeitpunkt der Erstdiagnose und manifestieren sich im Verlauf der Erkrankung bei 2 von 3 Patienten. Die zerebrale Krankheitsmanifestation wurde lange Zeit als prognostisch ungünstig eingestuft. Betroffene Patienten wurden regelhaft von Therapiestudien unter Berücksichtigung der ungünstigen Prognose ausgeschlossen. Im Kontext zielgerichteter molekularer Therapiestrategien und etablierter immunonkologischer Systemtherapien stellt die Blut-Hirn-Schranke mittlerweile keine unüberwindbare Barriere mehr dar. Die Therapie von Hirnmetastasen erfordert aber stets die Betreuung in einem interdisziplinären Team und muss als Zentrumsaufgabe angesehen werden. Unter Berücksichtigung von Anzahl, Größe und Lokalisation der Hirnmetastasen, Neurologie und Allgemeinzustand, Komorbiditäten, potenzieller Lebenserwartung und Wunsch des Patienten, aber auch Tumorbiologie inklusive molekularer Veränderungen, extrakranieller Tumorlast und Verfügbarkeit einer ZNS-wirksamen Therapie erfolgt die differenzierte Therapieentscheidung. Hierbei werden mittlerweile häufig Systemtherapien sowie lokale neurochirurgische und strahlentherapeutische Therapiekonzepte kombiniert im Sinne optimierter und prognoseverbessernder Therapiestrategien.
The Ischemic Tolerance up to Four Hours of Free Jejunum Flap: A Retrospective Cohort Study
Authors: Kagaya Yu , Takanashi Ryo , Arikawa Masaki , Kageyama Daisuke , Higashino Takuya , Akazawa Satoshi 
Published: January 2024

Abstract
Background While free jejunum transfer (FJT) following total pharyngo-laryngo-esophagectomy (TPLE) is a reliable reconstruction technique, the jejunum flap is viewed as more susceptible to ischemia than a standard free flap. Animal studies have indicated that the jejunum can tolerate ischemia for as little as 2 to 3 hours. Clinical studies also reported increased complications after the FJT with more than 3 hours of ischemia. Traditionally, our institution has carried out FJT with an initial intestinal anastomosis, followed by a vascular anastomosis, which often results in extended jejunal ischemia time. In this study, we retrospectively examined the actual tolerance of the jejunum to ischemia, considering perioperative complications and postoperative dysphagia.
Methods We retrospectively studied 402 consecutive cases involving TPLE + FJT. Patients were divided into five groups based on jejunum ischemia time (∼119 minutes, 120∼149 minutes, 150∼179 minutes, 180∼209 minutes, 210 minutes∼), with each variable and result item compared between the groups. Univariate and multivariate analyses were conducted to identify independent factors influencing the four results: three perioperative complications (pedicle thrombosis, anastomotic leak, surgical site infection) and dysphagia at 6 months postoperatively.
Results The mean jejunal ischemia time was 164.6 ± 28.4 (90–259) minutes. When comparing groups divided by jejunal ischemia time, we found no significant differences in overall outcomes or complications. Our multivariate analyses indicated that jejunal ischemia time did not impact the three perioperative complications and postoperative dysphagia.
Conclusion In TPLE + FJT, a jejunal ischemia time of up to 4 hours had no effect on perioperative complications or postoperative dysphagia. The TPLE + FJT technique, involving a jejunal anastomosis first followed by vascular anastomosis, benefits from an easier jejunal anastomosis but suffers from a longer jejunal ischemia time. However, we found that ischemia time does not pose significant problems, although we have not evaluated the effects of jejunal ischemia extending beyond 4 hours.
Synthesis of C-Glucoside Analogues of Naturally Occurring Phenyl­ethanoid O-Glucosides
Authors: Aidhen Indrapal S. , Subramanyam Amudala , Sumit Sumit 
Published: January 2024

AbstractStructural modifications of natural products has been a highly effective approach in the search for new leads with improved biological activity, aqueous solubility, and stability. Phenylethanoid glycosides (PEGs), as natural compounds, have attracted great attention due to their promising biological activities. These activities include neuroprotection, antioxidant, immunoregulation, anti-inflammatory, and analgesic effects, as well as antitumor, antiviral, and hepatoprotective abilities. Three potent PEGs, acteoside, echinacoside, and salidroside, are gaining renewed interest in this class of compounds. However, being O-glycosides, PEGs have low bioavailability due to factors such as poor intestinal permeability and low hydrolytic stability. The promising pharmacological properties and the limitations have inspired us to synthesize C-analogues that are expected to be hydrolytically stable.
Blow-Out Fracture of Orbit (Reconstructed with Stent Campo)
Authors: Lamba P. A. , Gupta A. K. , Shukla K. N. 
Published: January 2024

SummaryA case of blow-out fracture of the orbit with herniation of the globe into the maxi-Hary antrum is presented. The floor was reconstructed using Stent campo with satisfactory repair and without any undue reaction to the compound. The literature of blow-out fractures is briefly reviewed. The use of Stent campo for repair of floor ol orbit is recommended as an emergency or temporary measure.
Theoretical modeling of organizational reflex in human resource management from the perspective of organizational biological approach
Authors: Papsiene Palmira 
Published: January 2024

AbstractThis article presents a framework that informs about routine and creative decision-making and management practices within an organization. The primary focus of the study is on the preparedness of human resources within the organization to effectively respond to information from the global environment and ensure optimal decision-making. Analysis of human resource management discourse, a review of biological organization theory, and a detailed examination of reflex arc theory using elements of human body analogy such as neurons, allowed us to model a system that examines the basis of decision-making of information coming from the global environment in an organization, and the conducted research allowed to discover how to improve organizational abilities to respond to external stimuli. Theoretical modeling techniques revealed connections between the organization and various systems, and computer simulation allowed to examine these connections in different situations using Spyder (Python 3.8 environment based on SciPy, NumPy, etc.), with all the necessary functions to perform calculations and visualize the results. In order to gain a deeper understanding of decision-making in the organization, a model has been developed that is able to effectively make a decision from the perspective of the organization’s biological approach. A computer simulation conducted in the course of the study indicated: (1) that according to the interests of the organization the model selected (20%) of information of interest, from which, according to the ability of the created model, (95%) was directed to form a routine response and (5%) was directed to a creative response; (2) the time efficiency of the routine response may be more effective than that of the creative response from (63.6%) to (90.7%); (3) the efficiency of the realistic scenario of the model’s performance is inferior (about 21%) than that of the optimistic scenario, but more effective (about 17%) than that of the pessimistic scenario, this means that the realistic scenario works better than predicted in the pessimistic scenario, making it positive for the suitability of the model. These findings provide valuable insights into an organization’s ability to respond quickly and make decisions in a competitive environment, which may have practical implications for organization management and strategies to improve the ability to respond to external factors.