bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predictors of occult lymph node metastasis in cutaneous head and neck melanoma
Authors: Ni Jonathan S. , Janz Tyler A. , Nguyen Shaun A. , Lentsch Eric J. 
Published: September 2019

ObjectiveTo use the Surveillance, Epidemiology, and End Results (SEER) database to verify the findings of a recent National Cancer Database (NCDB) study that identified factors predicting occult nodal involvement in cutaneous head and neck melanoma (CHNM) while identifying additional predictors of occult nodal metastasis and comparing two distinct cancer databases.MethodsCases of CHNM in the SEER database diagnosed between 2004 and 2014 were identified. Demographic information and oncologic data were obtained. Univariate and multivariate analysis were performed to identify factors associated with pathologic nodal positivity.ResultsThere were 34002 patients with CHNM identified. Within this population, 16232 were clinically node‐negative, 1090 of which were found to be pathologically node‐positive. On multivariate analysis, factors associated with an increased risk of occult nodal metastasis included increasing depth of invasion (stepwise increase in adjusted odds ratio [OR]), nodular histology (aOR: 1.47 [95% CI: 1.21–1.80]), ulceration (aOR: 1.74 [95% CI: 1.48–2.05]), and mitoses (aOR: 1.86 [95% CI: 1.36–2.54]). Factors associated with a decreased risk of occult nodal metastasis included female sex (aOR: 0.80 [0.67–0.94]) and desmoplastic histology (aOR: 0.37 [95% CI: 0.24–0.59]). Between the SEER database and the NCDB, factors associated with occult nodal involvement were similar except for nodular histology and female sex, which did not demonstrate significance in the NCDB.ConclusionRegarding clinically node‐negative CHNM, the SEER database and the NCDB have similarities in demographic information but differences in baseline population sizes and tumor characteristics that should be considered when comparing findings between the two databases.Level of evidence4.
Promoting surface oxygen vacancies on ceria via light pretreatment to enhance catalytic ozonation
Authors: Esmailpour Ali Asghar , Moradi Sina , Yun Jimmy , Scott Jason , Amal Rose 
Published: September 2019

Oxygen vacancies catalyzed ozone into hydroxyl radicals which accelerated organic mineralization. Light pre-treatment of ceria intensifies its oxygen vacancy defect levels which are central to its performance in catalytic ozonation.
Bright C2H emission in protoplanetary discs in Lupus: high volatile C/O > 1 ratios
Authors: Miotello A. , Facchini S. , van Dishoeck E. F. , Cazzoletti P. , Testi L. , Williams J. P. , Ansdell M. , van Terwisga S. , van der Marel N. 
Published: September 2019

Context. Recent ALMA surveys in different star-forming regions have shown that CO emission in protoplanetary discs is much fainter than expected. Accordingly, CO-based gas masses and gas to dust ratios are orders of magnitude lower than previously thought. This may be explained either as fast gas dispersal, or as chemical evolution and locking up of volatiles in larger bodies leading to the low observed CO fluxes. The latter processes lead to enhanced C/O ratios in the gas, which may be reflected in enhanced abundances of carbon-bearing molecules like C2H.
Aims. The goal of this work is to use C2H observations to understand whether low CO fluxes are caused by volatile depletion or by fast gas dissipation.
Methods. We present ALMA Cycle 4 C2H (N = 3–2, J = 7∕2–5∕2, F = 4–3 and F = 3–2) observations of a subsample of nine sources in the Lupus star-forming region. The integrated C2H emission is determined and compared to previous CO isotopologue observations and physical-chemical model predictions.
Results. Seven out of nine discs are detected in C2H, whose line emission is almost as bright as 13CO. All detections are significantly brighter than the typical sensitivity of the observations, hinting at a bimodal distribution of the C2H line intensities. This conclusion is strengthened when our observations are compared with additional C2H observations of other discs. When compared with physical-chemical models, the observed C2H fluxes can be reproduced only if some level of volatile carbon and oxygen depletion is allowed and [C]/[O] > 1 in the gas. Models with reduced gas-to-dust ratios near unity however fail to reproduce the observed C2H line luminosity. A steeper than linear correlation between C2H and CN emission line is found for the Lupus discs. This is linked to the fact that C2H emission lines are affected more strongly by [C]/[O] variations than CN lines. Ring-like structures are detected both in C2H and in continuum emission but, as for CN, they do not seem to be connected. The source Sz 71 shows ring-shaped emission in both C2H and CN with the location of the peak intensity coinciding, within our 30 au resolution.
Conclusions. Our new ALMA C2H observations favour volatile carbon and oxygen depletion rather than fast gas dispersal to explain the faint CO observations for most of the discs. This result has implications for disc-evolution and planet-formation theories, as disc gas masses may be larger than expected if CO is considered to be the main carbon carrier in the gas phase.
Linking the evolution of terrestrial interiors and an early outgassed atmosphere to astrophysical observations
Authors: Bower Dan J. , Kitzmann Daniel , Wolf Aaron S. , Sanan Patrick , Dorn Caroline , Oza Apurva V. 
Published: September 2019

Context. A terrestrial planet is molten during formation and may remain molten due to intense insolation or tidal forces. Observations favour the detection and characterisation of hot planets, potentially with large outgassed atmospheres.
Aims. We aim to determine the radius of hot Earth-like planets with large outgassing atmospheres. Our goal is to explore the differences between molten and solid silicate planets on the mass–radius relationship and transmission and emission spectra.
Methods. An interior–atmosphere model was combined with static structure calculations to track the evolving radius of a hot rocky planet that outgasses CO2 and H2O. We generated synthetic emission and transmission spectra for CO2 and H2O dominated atmospheres.
Results. Atmospheres dominated by CO2 suppress the outgassing of H2O to a greater extent than previously realised since previous studies applied an erroneous relationship between volatile mass and partial pressure. We therefore predict that more H2O can be retained by the interior during the later stages of magma ocean crystallisation. Formation of a surface lid can tie the outgassing of H2O to the efficiency of heat transport through the lid, rather than the radiative timescale of the atmosphere. Contraction of the mantle, as it cools from molten to solid, reduces the radius by around 5%, which can partly be offset by the addition of a relatively light species (e.g. H2O versus CO2) to the atmosphere.
Conclusions. A molten silicate mantle can increase the radius of a terrestrial planet by around 5% compared to its solid counterpart, or equivalently account for a 13% decrease in bulk density. An outgassing atmosphere can perturb the total radius, according to its composition, notably the abundance of light versus heavy volatile species. Atmospheres of terrestrial planets around M-stars that are dominated by CO2 or H2O can be distinguished by observing facilities with extended wavelength coverage (e.g. JWST).
Influence of inelastic collisions with hydrogen atoms on the non-local thermodynamic equilibrium line formation for Fe I and Fe II in the 1D model atmospheres of late-type stars
Authors: Mashonkina L. , Sitnova T. , Yakovleva S. A. , Belyaev A. K. 
Published: September 2019

Context. Iron plays a crucial role in studies of late-type stars. In their atmospheres, neutral iron is the minority species, and lines of Fe I are subject to the departures from local thermodynamic equilibrium (LTE). In contrast, one believes that LTE is a realistic approximation for Fe II lines. The main source of the uncertainties in the non-LTE (NLTE) calculations for cool atmospheres is a treatment of inelastic collisions with hydrogen atoms.
Aims. Our aim is to investigate the effect of Fe I + H I and Fe II + H I collisions and their different treatments on the Fe I/Fe II ionisation equilibrium and iron abundance determinations for three Galactic halo benchmark stars (HD 84937, HD 122563, and HD 140283) and a sample of 38 very metal-poor giants in the dwarf galaxies with well known distances.
Methods. We performed the NLTE calculations for Fe I–Fe II by applying quantum-mechanical rate coefficients for collisions with H I from recent papers.
Results. We find that collisions with H I serve as efficient thermalisation processes for Fe II, to an extent that the NLTE abundance corrections for Fe II lines do not exceed 0.02 dex, in absolute value, for [Fe/H] ≳−3, and reach +0.06 dex at [Fe/H] ~−4. For a given star, different treatments of Fe I + H I collisions lead to similar average NLTE abundances from the Fe I lines, although discrepancies in the NLTE abundance corrections exist for individual lines. By using quantum-mechanical collisional data and the Gaia-based surface gravity, we obtain consistent abundances from the two ionisation stages, Fe I and Fe II, for red giant HD 122563. For turn-off star HD 84937, and subgiant HD 140283, we analyse the iron lines in the visible and the ultra-violet (UV, 1968–2990 Å) ranges. For either Fe I or Fe II, abundances from the visible and UV lines are found to be consistent in each star. The NLTE abundances from the two ionisation stages agree within 0.10 dex and 0.13 dex for two different treatments of Fe I + H I collisions. The Fe I/Fe II ionisation equilibrium is achieved for each star of our stellar sample in the dwarf galaxies, with the exception of stars at [Fe/H] ≲−3.7.
Synthesizing carbon nanotubes in space
Authors: Chen Tao , Li Aigen 
Published: September 2019

Context. As the fourth most abundant element in the universe, carbon (C) is widespread in the interstellar medium (ISM) in various allotropic forms (e.g. fullerenes have been identified unambiguously in many astronomical environments, the presence of polycyclic aromatic hydrocarbon molecules in space has been commonly acknowledged, and presolar graphite, as well as nanodiamonds, have been identified in meteorites). As stable allotropes of these species, whether carbon nanotubes (CNTs) and their hydrogenated counterparts are also present in the ISM or not is unknown.
Aims. The aim of the present works is to explore the possible routes for the formation of CNTs in the ISM and calculate their fingerprint vibrational spectral features in the infrared (IR).
Methods. We studied the hydrogen-abstraction and acetylene-addition (HACA) mechanism and investigated the synthesis of nanotubes using density functional theory (DFT). The IR vibrational spectra of CNTs and hydrogenated nanotubes (HNTs), as well as their cations, were obtained with DFT.
Results. We find that CNTs could be synthesized in space through a feasible formation pathway. CNTs and cationic CNTs, as well as their hydrogenated counterparts, exhibit intense vibrational transitions in the IR. Their possible presence in the ISM could be investigated by comparing the calculated vibrational spectra with astronomical observations made by the Infrared Space Observatory, Spitzer Space Telescope, and particularly the upcoming James Webb Space Telescope.
Active minimization of non-common path aberrations in long-exposure imaging of exoplanetary systems
Authors: Singh Garima , Galicher Raphaël , Baudoz Pierre , Dupuis Olivier , Ortiz Manuel , Potier Axel , Thijs Simone , Huby Elsa 
Published: September 2019

Context. Spectroscopy of exoplanets is very challenging because of the high star-planet contrast. A technical difficulty in the design of imaging instruments is the noncommon path aberrations (NCPAs) between the adaptive optics (AO) sensing and the science camera, which induce planet-resembling stellar speckles in the coronagraphic science images. In an observing sequence of several long exposures, quickly evolving NCPAs average out and leave behind an AO halo that adds photon noise to the planet detection. Static NCPA can be calibrated a posteriori using differential imaging techniques. However, NCPAs that evolve during the observing sequence do not average out and cannot be calibrated a posteriori. These quasi-static NCPAs are one of the main limitations of the current direct imaging instruments such as SPHERE, GPI, and SCExAO.
Aims. Our aim is to actively minimize the quasi-static speckles induced in long-exposure images. To do so, we need to measure the quasi-static speckle field above the AO halo.
Methods. The self-coherent camera (SCC) is a proven technique which measures the speckle complex field in the coronagraphic science images. It is routinely used on the THD2 bench to reach contrast levels of < 10−8 in the range 5 − 12 λ/D in space-related conditions. To test the SCC in ground conditions on THD2, we optically simulated the residual aberrations measured behind the SPHERE/VLT AO system under good observing conditions.
Results. We demonstrate in the laboratory that the SCC can minimize the quasi-static speckle intensity in the science images down to a limitation set by the AO halo residuals. The SCC reaches 1σ raw contrast levels below 10−6 in the region 5 − 12 λ/D at 783.25 nm in our experiments.
Conclusions. The results presented in this article reveal an opportunity for the current and future high-contrast imaging systems to adapt the SCC for real-time measurement and correction of quasi-static speckles in long-exposure science observations from the ground.
Hot subdwarf wind models with accurate abundances
Authors: Krtička J. , Janík J. , Krtičková I. , Mereghetti S. , Pintore F. , Németh P. , Kubát J. , Vučković M. 
Published: September 2019

Context. Hot subdwarfs are helium burning objects in late stages of their evolution. These subluminous stars can develop winds driven by light absorption in the lines of heavier elements. The wind strength depends on chemical composition which can significantly vary from star to star.
Aims. We aim to understand the influence of metallicity on the strength of the winds of the hot hydrogen-rich subdwarfs HD 49798 and BD+18° 2647.
Methods. We used high-resolution UV and optical spectra to derive stellar parameters and abundances using the TLUSTY and SYNSPEC codes. For derived stellar parameters, we predicted wind structure (including mass-loss rates and terminal velocities) with our METUJE code.
Results. We derived effective temperature Teff = 45 900 K and mass M = 1.46 M⊙ for HD 49798 and Teff = 73 000 K and M = 0.38 M⊙ for BD+18° 2647. The derived surface abundances can be interpreted as a result of interplay between stellar evolution and diffusion. The subdwarf HD 49798 has a strong wind that does not allow for chemical separation and consequently the star shows solar chemical composition modified by hydrogen burning. On the other hand, we did not find any wind in BD+18° 2647 and its abundances are therefore most likely affected by radiative diffusion. Accurate abundances do not lead to a significant modification of wind mass-loss rate for HD 49798, because the increase of the contribution of iron and nickel to the radiative force is compensated by the decrease of the radiative force due to other elements. The resulting wind mass-loss rate Ṁ = 2.1 × 10−9 M⊙ yr−1 predicts an X-ray light curve during the eclipse which closely agrees with observations. On the other hand, the absence of the wind in BD+18° 2647 for accurate abundances is a result of its peculiar chemical composition.
Conclusions. Wind models with accurate abundances provide more reliable wind parameters, but the influence of abundances on the wind parameters is limited in many cases.
The supernova remnant population of the Small Magellanic Cloud
Authors: Maggi Pierre , Filipović Miroslav D. , Vukotić Branislav , Ballet Jean , Haberl Frank , Maitra Chandreyee , Kavanagh Patrick , Sasaki Manami , Stupar Milorad 
Published: September 2019

Aims.We present a comprehensive study on the supernova remnant (SNR) population of the Small Magellanic Cloud (SMC). We measured multiwavelength properties of the SMC SNRs and compare them to those of the Large Magellanic Cloud (LMC) population.Methods.This study combines the large dataset ofXMM-Newtonobservations of the SMC, archival and recent radio continuum observations, an optical line emission survey, and new optical spectroscopic observations. We were therefore able to build a complete and clean sample of 19 confirmed and four candidate SNRs. The homogeneous X-ray spectral analysis allowed us to search for SN ejecta and Fe K line emission, and to measure interstellar medium abundances. We estimated the ratio of core-collapse to type Ia supernova rates of the SMC based on the X-ray properties and the local stellar environment of each SNR.Results.After the removal of unconfirmed or misclassified objects, and the addition of two newly confirmed SNRs based on multi-wavelength features, we present a final list of 21 confirmed SNRs and two candidates. While no Fe K line is detected even for the brightest and youngest SNR, we find X-ray evidence of SN ejecta in 11 SNRs. We estimate a fraction of 0.62–0.92 core-collapse supernova for every supernova (90% confidence interval), higher than in the LMC. The difference can be ascribed to the absence of the enhanced star-formation episode in the SMC, which occurred in the LMC 0.5–1.5 Gyr ago. The hot-gas abundances of O, Ne, Mg, and Fe are 0.1–0.2 times solar. Their ratios, with respect to SMC stellar abundances, reflect the effects of dust depletion and partial dust destruction in SNR shocks. We find evidence that the ambient medium probed by SMC SNRs is less disturbed and less dense on average than in the LMC, consistent with the different morphologies of the two galaxies.
Evaluation of the Effects of Delayed Cord Clamping in Infants of Diabetic Mothers
Authors: Korkut Sabriye , Oğuz Yüksel , Bozkaya Davut , Türkmen Gülenay Gençosmanoğlu , Kara Özgür , Uygur Dilek , Oğuz Şerife Suna 
Published: September 2019

AbstractObjective This study aimed to investigate the effect of delayed cord clamping (DCC) in infants of diabetic mothers.Study Design Women who had diabetes throughout their pregnancy and gave birth at 37 weeks of gestation or later were included in the study along with their babies. Early cord clamping was performed as soon as possible after birth, while DCC was performed by clamping 60 second after birth. The two groups were compared in terms of venous hematocrit (htc) levels and rates of hypoglycemia, jaundice requiring phototherapy, and respiratory distress.Results Venous htc levels at postnatal 6 and 24 hours were significantly higher in the DCC group (p = 0.0001). Polycythemia rates were higher in the DCC group at both 6 and 24 hours, but partial exchange transfusion (PET) was not needed in either group. There were no differences between the groups with regard to the rates of hypoglycemia or jaundice requiring phototherapy. Rate of admission to the neonatal intensive care unit (NICU) was lower in the DCC group.Conclusion Although DCC increased the rate of polycythemia, it did not result in PET requirement. Moreover, DCC reduced the severity of respiratory distress and the rate of admission to NICU due to respiratory distress.
Gracilis Myocutaneous Flap: Adding to the Armamentarium of Complex Sacrococcygeal Defect Reconstruction
Authors: Preetha Rani K. , Satish Kumar J. , Singaravelu V. , Deyonna Fernandes 
Published: September 2019

Abstract
Background With increasing radicality of rectal cancer surgeries, the postoperative defects are becoming more complex. This demands an ideal reconstructive option with minimal morbidity to the patient. Although vertical rectus abdominis myocutaneous (VRAM) flap is the commonly used flap, gracilis myocutaneous flap is increasingly being performed to avoid morbidity associated with VRAM flap.
Results We share our experience about two of our patients treated for rectal malignancy with pelvic exenteration who were reconstructed immediately with pedicled gracilis myocutaneous flap. Both the patients had an uneventful postoperative recovery period and were discharged on postoperative day 10. During follow-up period both patients had a healthy flap with no evidence of recurrence. No perineal hernias or gross dehiscence of skin closure occurred.
Conclusion Gracilis myocutaneous flap has its own place with unique advantages adding to the armamentarium of reconstructive options for complex perineal defects, thereby avoiding the morbidity associated with VRAM flap. It stands as a reliable alternative in patients where VRAM cannot be used.
Platelet Transfusion Thresholds: How Low Can We Go in Respect to Platelet Counting?
Authors: Lippi Giuseppe , Favaloro Emmanuel J. , Buoro Sabrina 
Published: September 2019

AbstractPlatelet transfusion is conventionally used to prevent or treat bleeding in patients with low platelet counts or impaired platelet function. The identification of accurate thresholds of platelet count for guiding platelet transfusion practices is a crucial aspect in health care to prevent adverse events, side effects, unwarranted costs for the health care service, and deprivation of supplies. This article is therefore aimed at providing a narrative overview on current guidelines and recommendations for platelet transfusion across many clinical settings, including platelet function disorders, and critically analyzing the available platelet transfusion thresholds according to the current analytical performance of platelet counting with automated hematological analyzers. Overall, universal agreement on the definition of platelet transfusion thresholds has not been reached. The degree of accuracy and imprecision of many fully automated hematological analyzers appears also unsatisfactory, especially at the lower thrombocytopenic range, and this may thus jeopardize the managed care of patients who are candidates for platelet transfusions. Potential solutions to overcome the current shortcomings of automated platelet counting are also discussed, encompassing the use of alternative tests for guiding platelet transfusion (e.g., thrombin generation assays or thromboelastography) along with innovative approaches for platelet enumeration (e.g., fluorescent labeling and flow cytometry).