bluuebunny/crossref_metadata_2025_split huggingface dataset:
White-collar sign as a predictor of outcome after endovascular treatment for cerebral aneurysms
Authors: Fukuda Kenji , Higashi Toshio , Okawa Masakazu , Iwaasa Mitsutoshi , Yoshioka Tsutomu , Inoue Tooru 
Published: May 2016

OBJECTIVE
The white-collar sign (WCS) is known as a thick neointimal tissue formation at the aneurysm neck after endovascular coil embolization of cerebral aneurysms, which may prevent aneurysm recanalization. The purpose of this study was to evaluate factors involved in the appearance of WCS and to identify radiological and clinical outcomes of treated aneurysms with WCS.

METHODS
The study included 140 patients with 149 aneurysms in which it was possible to confirm the aneurysm neck between the aneurysm sac and parent artery by using conventional angiography. The WCS was defined as a radiolucent band at the aneurysm neck on the angiogram at 6 months after initial embolization. The radiological outcome was evaluated using MR angiography.

RESULTS
In 23 of 149 aneurysms (15.4%), a WCS appeared. The WCS-positive group had a significantly smaller neck size (3.3 ± 0.8 mm vs 4.2 ± 1.1 mm, p < 0.001) and smaller aneurysm size (4.3 ± 0.9 mm vs 6.0 ± 2.1 mm, p < 0.001) than the WCS-negative group. Multivariate analysis revealed that WCS appearance was associated with small neck size (OR 0.376, 95% CI 0.179–0.787; p = 0.009). In 106 of 149 aneurysms, the rate of complete occlusion was significantly higher in the WCS-positive group (18/18, 100%) than in the WCS-negative group (n = 54/88, 61.4%; p = 0.001) in the mean follow-up period of 31.0 ± 9.7 months (range 5–52 months). Neither major recanalization nor rupture of the aneurysm occurred in the WCS-positive group.

CONCLUSIONS
Appearance of the WCS was associated with complete occlusion and good clinical outcome after endovascular coil embolization. The WCS would help to determine the prognosis of cerebral aneurysms after endovascular treatment.
Biomechanical fixation properties of cortical versus transpedicular screws in the osteoporotic lumbar spine: an in vitro human cadaveric model
Authors: Sansur Charles A. , Caffes Nicholas M. , Ibrahimi David M. , Pratt Nathan L. , Lewis Evan M. , Murgatroyd Ashley A. , Cunningham Bryan W. 
Published: May 2016

OBJECTIVE
Optimal strategies for fixation in the osteoporotic lumbar spine remain a clinical issue. Classic transpedicular fixation in the osteoporotic spine is frequently plagued with construct instability, often due to inadequate cortical screw–bone purchase. A cortical bone trajectory maximizes bony purchase and has been reported to provide increased screw pullout strength. The aim of the current investigation was to evaluate the biomechanical efficacy of cortical spinal fixation as a surgical alternative to transpedicular fixation in the osteoporotic lumbar spine under physiological loading.

METHODS
Eight fresh-frozen human spinopelvic specimens with low mean bone mineral densities (T score less than or equal to –2.5) underwent initial destabilization, consisting of laminectomy and bilateral facetectomies (L2–3 and L4–5), followed by pedicle or cortical reconstructions randomized between levels. The surgical constructs then underwent fatigue testing followed by tensile load to failure pullout testing to quantify screw pullout force.

RESULTS
When stratifying the pullout data with fixation technique and operative vertebral level, cortical screw fixation exhibited a marked increase in mean load at failure in the lower vertebral segments (p = 0.188, 625.6 ± 233.4 N vs 450.7 ± 204.3 N at L-4 and p = 0.219, 640.9 ± 207.4 N vs 519.3 ± 132.1 N at L-5) while transpedicular screw fixation demonstrated higher failure loads in the superior vertebral elements (p = 0.024, 783.0 ± 516.1 N vs 338.4 ± 168.2 N at L-2 and p = 0.220, 723.0 ± 492.9 N vs 469.8 ± 252.0 N at L-3). Although smaller in diameter and length, cortical fixation resulted in failures that were not significantly different from larger pedicle screws (p > 0.05, 449.4 ± 265.3 N and 541.2 ± 135.1 N vs 616.0 ± 384.5 N and 484.0 ± 137.1 N, respectively).

CONCLUSIONS
Cortical screw fixation exhibits a marked increase in mean load at failure in the lower vertebral segments and may offer a viable alternative to traditional pedicle screw fixation, particularly for stabilization of lower lumbar vertebral elements with definitive osteoporosis.
Trans sodium crocetinate with temozolomide and radiation therapy for glioblastoma multiforme
Authors: Gainer John L. , Sheehan Jason P. , Larner James M. , Jones David R. 
Published: May 2016

OBJECTIVE
A new drug, trans sodium crocetinate (TSC), has been developed to enhance the delivery of oxygen to hypoxic tissues. Cancerous tumors, such as glioblastoma multiforme (GBM), are very hypoxic, and it has been suggested that radiation therapy (RT) is more beneficial if tumors are better oxygenated. A Phase I/II clinical trial was conducted to determine the effect of adding TSC to RT sessions.

METHODS
An open, single-arm clinical trial incorporating the standard of care (SOC) for GBM was conducted at 18 clinical sites. There were 6 weeks of RT consisting of 2 Gy/day for 5 days/week, beginning after an initial resection or stereotactic biopsy to confirm GBM. Temozolomide (TMZ), 75 mg/m2, was given before each RT session. The TSC, 0.25 mg/kg, was intravenously administered around 45 minutes before an RT session 3 days/week, usually on Monday, Wednesday, and Friday.
A Phase I run-in period included 2 cohorts. The first cohort contained 3 patients who were given a half dose of the intravenous TSC (that is, 0.25 mg/kg, 3 times per week for only the first 3 weeks of RT). After a Safety Monitoring Committee (SMC) had verified that no dose-limiting toxicity (DLT) had occurred, a second cohort of 6 patients was given the same dosage of TSC but for the full 6 weeks of RT. After the SMC verified that no DLTs had occurred, Phase II began, with the administration of the full 18 doses of TSC. Fifty additional patients were enrolled during Phase II.
Following the completion of RT, the patients rested for a month. After that, SOC TMZ chemotherapy (150–200 mg/m2) was administered for 5 days of the 1st week of 6 monthly cycles. No TSC was administered during this chemotherapy phase or later in the trial. Any other follow-up therapies were administered at the discretion of the individual investigators.

RESULTS
Kaplan-Meier analysis showed that 36% of the full-dose TSC patients were alive at 2 years, compared with historical survival values ranging from 27% to 30% for the SOC. Survival for the biopsy-only subset of patients was 40%, as compared with 42.9% for those patients having a complete resection before treatment. In addition, 2 of the 3 Phase I, Cohort 1 patients survived at 2 years. Contrast MRI data suggested that considerable pseudoprogression had occurred. Both Karnofsky Performance Status (KPS) scores and quality of life (QOL) questionnaires indicated that a good quality of life existed for most patients throughout the trial. No serious adverse events occurring in the trial were attributed to TSC.

CONCLUSIONS
This trial contained a single arm consisting of 59 patients. The results strongly suggested that adding TSC during RT is beneficial for the treatment of GBM. Trans sodium crocetinate offers a novel, easily implemented way to combat hypoxia in tumor tissue.
Clinical trial registration no.: NCT01465347 (clinicaltrials.gov)
FUNDAMENTAL PARAMETERS OF KEPLER ECLIPSING BINARIES. I. KIC 5738698
Authors: Matson Rachel A. , Gies Douglas R. , Guo Zhao , Orosz Jerome A. 
Published: May 2016

ABSTRACT
Eclipsing binaries serve as a valuable source of stellar masses and radii that inform stellar evolutionary models and provide insight into additional astrophysical processes. The exquisite light curves generated by space-based missions such as Kepler offer the most stringent tests to date. We use the Kepler light curve of the 4.8 day eclipsing binary KIC 5739896 with ground based optical spectra to derive fundamental parameters for the system. We reconstruct the component spectra to determine the individual atmospheric parameters, and model the Kepler photometry with the binary synthesis code Eclipsing Light Curve to obtain accurate masses and radii. The two components of KIC 5738698 are F-type stars with

M

1

=

1.39
±
0.04

M

⊙

,

M

2

=

1.34
±
0.06

M

⊙

, and

R

1

=

1.84
±
0.03

R

⊙

,

R

2

=

1.72
±
0.03

R

⊙

. We also report a small eccentricity (

e
≲
0.0017

) and unusual albedo values that are required to match the detailed shape of the Kepler light curve. Comparison with evolutionary models indicate an approximate age of 2.3 Gyr for the system.
DUST DIFFUSION AND SETTLING IN THE PRESENCE OF COLLISIONS: TRAPPING (SUB)MICRON GRAINS IN THE MIDPLANE
Authors: Krijt Sebastiaan , Ciesla Fred J. 
Published: May 2016

ABSTRACT
In protoplanetary disks, the distribution and abundance of small (sub)micron grains are important for a range of physical and chemical processes. For example, they dominate the optical depth at short wavelengths and their surfaces are the sites of many important chemical reactions, such as the formation of water. Based on their aerodynamical properties (i.e., their strong dynamical coupling with the surrounding gas) it is often assumed that these small grains are well-mixed with the gas. Our goal is to study the vertical (re)distribution of grains taking into account settling, turbulent diffusion, and collisions with other dust grains. Assuming a fragmentation-limited background dust population, we developed a Monte Carlo approach that follows single monomers as they move through a vertical column of gas and become incorporated in different aggregates as they undergo sticking and fragmenting collisions. We find that (sub)micron grains are not necessarily well-mixed vertically, but can become trapped in a thin layer with a scale height that is significantly smaller than that of the gas. This collisional trapping occurs when the timescale for diffusion is comparable to or longer than the collision timescale in the midplane and its effect is strongest when the most massive particles in the size distribution show significant settling. Based on simulations and analytical considerations, we conclude that for typical dust-to-gas ratios and turbulence levels, the collisional trapping of small grains should be a relatively common phenomenon. The absence of trapping could then indicate a low dust-to-gas ratio, possibly because a large portion of the dust mass has been removed through radial drift or is locked up in planetesimals.
FREQUENCY MODULATION OF DIRECTLY IMAGED EXOPLANETS: GEOMETRIC EFFECT AS A PROBE OF PLANETARY OBLIQUITY
Authors: Kawahara Hajime 
Published: May 2016

ABSTRACT
We consider the time–frequency analysis of a scattered light curve of a directly imaged exoplanet. We show that the geometric effect due to planetary obliquity and orbital inclination induce the frequency modulation of the apparent diurnal periodicity. We construct a model of the frequency modulation and compare it with the instantaneous frequency extracted from the pseudo-Wigner distribution of simulated light curves of a cloudless Earth. The model provides good agreement with the simulated modulation factor, even for the light curve with Gaussian noise comparable to the signal. Notably, the shape of the instantaneous frequency is sensitive to the difference between the prograde, retrograde, and pole-on spin rotations. While our technique requires the albedo map to be static, it does not need to solve the albedo map of the planet. The time–frequency analysis is complementary to other methods which utilize the amplitude modulation. This paper demonstrates the importance of the frequency domain of the photometric variability for the characterization of directly imaged exoplanets in future research.
HESS J1943+213: A NON-CLASSICAL HIGH-FREQUENCY-PEAKED BL LAC OBJECT
Authors: Straal S. M. , Gabányi K. É. , Leeuwen J. van , Clarke T. E. , Dubner G. , Frey S. , Giacani E. , Paragi Z. 
Published: May 2016

ABSTRACT
HESS J1943+213 is an unidentified TeV source that is likely a high-frequency-peaked BL Lac (HBL) object, but that is also compatible with a pulsar wind nebula (PWN) nature. Each of these enormously different astronomical interpretations is supported by some of the observed unusual characteristics. In order to finally classify and understand this object, we took a three-pronged approach, through time-domain, high angular resolution, and multi-frequency radio studies. First, our deep time-domain observations with the Arecibo telescope failed to uncover the putative pulsar powering the proposed PWN. We conclude with ∼70% certainty that HESS J1943+213 does not host a pulsar. Second, long-baseline interferometry of the source with e-MERLIN at 1.5 and 5 GHz shows only a core, that is, a point source at

–100 mas resolution. Its 2013 flux density is about one-third lower than that detected in the 2011 observations with similar resolution. This radio variability of the core strengthens the HBL object hypothesis. Third, additional evidence against the PWN scenario comes from the radio spectrum we compiled. The extended structure follows a power-law behavior with spectral index

while the core component displays a flat spectrum (

). In contrast, the radio synchrotron emission of PWNe predicts a single power-law distribution. Overall, we rule out the PWN hypothesis and conclude that the source is a BL Lac object. The consistently high fraction (70%) of the flux density from the extended structure then leads us to conclude that HESS J1943+213 must be a non-classical HBL object.
THE COMPLETE, TEMPERATURE RESOLVED EXPERIMENTAL SPECTRUM OF METHYL FORMATE (HCOOCH3) BETWEEN 214.6 AND 265.4 GHz
Authors: McMillan James P. , Fortman Sarah M. , Neese Christopher F. , Lucia Frank C. De 
Published: May 2016

ABSTRACT
Because methyl formate (HCOOCH3) is abundant in the interstellar medium and has a strong, complex spectrum, it is a major contributor to the list of identified astrophysical lines. Because of its spectral complexity, with many low lying torsional and vibrational states, the quantum mechanical (QM) analysis of its laboratory spectrum is challenging and thus incomplete. As a result it is assumed that methyl formate is also one of the major contributors to the lists of unassigned lines in astrophysical spectra. This paper provides a characterization, without the need for QM analysis, of the spectrum of methyl formate between 214.6 and 265.4 GHz for astrophysically significant temperatures. The experimental basis for this characterization is a set of 425 spectra, with absolute intensity calibration, recorded between 248 and 408 K. Analysis of these spectra makes possible the calculation of the Complete Experimental Spectrum of methyl formate as a function of temperature. Of the 7132 strongest lines reported in this paper, 2523 are in the QM catalogs. Intensity differences of 5%–10% from those calculated via QM models were also found. Results are provided in a frequency point-by-point catalog that is well suited for the simulation of overlapped spectra. The common astrophysical line frequency, line strength, and lower state energy catalog is also provided.
PAIRS AND GROUPS OF GENETICALLY RELATED LONG-PERIOD COMETS AND PROPOSED IDENTITY OF THE MYSTERIOUS LICK OBJECT OF 1921
Authors: Sekanina Zdenek , Kracht Rainer 
Published: May 2016

ABSTRACT
We present the history of investigation of the dynamical properties of pairs and groups of genetically related long-period comets (other than the Kreutz sungrazing system). Members of a comet pair or group move in nearly identical orbits, and their origin as fragments of a common parent comet is unquestionable. The only variable is the time of perihelion passage, which differs considerably from member to member owing primarily to an orbital-momentum increment acquired during breakup. Meter-per-second separation velocities account for gaps of years or tens of years, thanks to the orbital periods of many millennia. The physical properties of individual members may not at all be alike, as illustrated by the trio of C/1988 A1, C/1996 Q1, and C/2015 F3. We exploit orbital similarity to examine whether the enigmatic and as-yet-unidentified object discovered from the Lick Observatory near the Sun at sunset on 1921 August 7 happened to be a member of such a pair and to track down the long-period comet to which it might be genetically related. Our search shows that the Lick object, which could not be a Kreutz sungrazer, was likely a companion to comet C/1847 C1 (Hind), whose perihelion distance was ∼9 R
⊙ and true orbital period was approximately 8300 yr. The gap of 74.4 yr between their perihelion times is consistent with a separation velocity of ∼1 m s−1 which sets the fragments apart following the parent's breakup in a general proximity of perihelion during the previous return to the Sun in the seventh millennium BCE.
FIRST DETECTION OF GAS-PHASE METHANOL IN A PROTOPLANETARY DISK
Authors: Walsh Catherine , Loomis Ryan A. , Öberg Karin I. , Kama Mihkel , van ’t Hoff Merel L. R. , Millar Tom J. , Aikawa Yuri , Herbst Eric , Widicus Weaver Susanna L. , Nomura Hideko 
Published: May 2016

ABSTRACT
The first detection of gas-phase methanol in a protoplanetary disk (TW Hya) is presented. In addition to being one of the largest molecules detected in disks to date, methanol is also the first disk organic molecule with an unambiguous ice chemistry origin. The stacked methanol emission, as observed with the Atacama Large Millimeter/submillimeter Array, is spectrally resolved and detected across six velocity channels (

>
3
σ

), reaching a peak signal-to-noise of

5.5
σ

, with the kinematic pattern expected for TW Hya. Using an appropriate disk model, a fractional abundance of

3
×

10

−
12

–
4
×

10

−
11

(with respect to H2) reproduces the stacked line profile and channel maps, with the favored abundance dependent upon the assumed vertical location (midplane versus molecular layer). The peak emission is offset from the source position, suggesting that the methanol emission has a ring-like morphology: the analysis here suggests it peaks at

≈
30

au

, reaching a column density

≈
3
–
6
×

10

12

cm−2. In the case of TW Hya, the larger (up to millimeter-sized) grains, residing in the inner 50 au, may thus host the bulk of the disk ice reservoir. The successful detection of cold gas-phase methanol in a protoplanetary disk implies that the products of ice chemistry can be explored in disks, opening a window into studying complex organic chemistry during planetary system formation.
SPIRAL WAVES TRIGGERED BY SHADOWS IN TRANSITION DISKS
Authors: Montesinos Matías , Perez Sebastian , Casassus Simon , Marino Sebastian , Cuadra Jorge , Christiaens Valentin 
Published: May 2016

ABSTRACT
Circumstellar asymmetries such as central warps have recently been shown to cast shadows on outer disks. We investigate the hydrodynamical consequences of such variable illumination on the outer regions of a transition disk, and the development of spiral arms. Using 2D simulations, we follow the evolution of a gaseous disk passively heated by the central star, under the periodic forcing of shadows with an opening angle of ∼28°. With a lower pressure under the shadows, each crossing results in a variable azimuthal acceleration, which in time develops into spiral density waves. Their pitch angles evolve from Π ∼ 15°–22° at the onset, to ∼11°–14°, over ∼65 au to 150 au. Self-gravity enhances the density contrast of the spiral waves, as also reported previously for spirals launched by planets. Our control simulations with unshadowed irradiation do not develop structures, except for a different form of spiral waves seen at later times only in the gravitationally unstable control case. Scattered light predictions in the H-band show that such illumination spirals should be observable. We suggest that spiral arms in the case-study transition disk HD 142527 could be explained as a result of shadowing from the tilted inner disk.
PROBABILISTIC INFERENCE OF BASIC STELLAR PARAMETERS: APPLICATION TO FLICKERING STARS*
Authors: Angus Ruth , Kipping David. M. 
Published: May 2016

ABSTRACT
The relations between observable stellar parameters are usually assumed to be deterministic. That is, given an infinitely precise measurement of independent variable, “x”, and some model, the value of dependent variable, “y” can be known exactly. In practice this assumption is rarely valid and intrinsic stochasticity means that two stars with exactly the same “x” will have slightly different “y”s. The relation between short-timescale brightness fluctuations (flicker) of stars and both surface gravity and stellar density are two such stochastic relations that have until now been treated as deterministic ones. We recalibrate these relations in a probabilistic framework, using hierarchical Bayesian modeling to constrain the instrinsic scatter in the relations. We find evidence for additional scatter in the relationship, that cannot be accounted for by the observational uncertainties alone. The scatter in surface gravity and stellar density does not depend on flicker, suggesting that using flicker as a proxy for

log
g

and ρ
⋆ is equally valid for dwarf and giant stars, despite the fact that the observational uncertainties tend to be larger for dwarfs.
New records of Gerromorpha and Nepomorpha (Insecta: Hemiptera: Heteroptera) from South America
Authors: Moreira Felipe , Rodrigues Higor , Barbosa Julianna , Reduciendo Klementová Barbora , Svitok Marek 
Published: May 2016

Aquatic and semiaquatic Heteroptera occur on all continents except Antarctica and occupy a wide variety of habitats, including lentic and lotic water bodies, perennial or temporary. In the Neotropical Region, there is a lack of knowledge concerning the geographical distribution of most represented species, which can only be solved by the collection of specimens in under-studied areas and publication of new records and lists of species.
New records are presented for eleven species of Gerromorpha and ten Nepomorpha, including first records from Venezuela (Brachymetra lata, Limnogonus hyalinus, Rhagovelia evidis, Tenagobia peruana, Limnocoris burmeisteri, L. fittkaui fittkaui, Placomerus micans, and Martarega gonostyla), the Venezuelan State of Bolívar (Cylindrostethus palmaris, R. elegans, R. tenuipes, and Ambrysus stali), the Brazilian State of Bahia (Martarega bentoi), Peru (Euvelia lata), and the Peruvian Region of Arequipa (Microvelia pulchella).
Une approche spatiale des instruments de l’action publique : l’exemple des réformes du secteur de la santé en Inde
Authors: Eliot Emmanuel 
Published: May 2016

Dans de nombreux pays du monde, les systèmes de soins sont affectés par des réformes de nature politique, organisationnelle et financière. Ces dernières contribuent à renforcer la concurrence, multiplier les interactions entre acteurs publics et privés et entre le local et le global. À partir de l’exemple du système de soins public indien, cet article insiste sur les difficultés de l’analyse des paysages sanitaires contemporains et présente les avantages d’une approche centrée sur l’étude des « instruments de l’action publique » (Lascoumes P., Le Galès P., 2005) et de leurs spatialités. Ces réflexions sont développées à partir de l’étude du rôle des Organisations Non Gouvernementales (ONG) dans les transformations du système de soins public. Une méthodologie est présentée et appliquée à l’étude de quatre ONG.
High-Temperature Self-Supplied Isolated Driver Module for GaN Power Transistors
Authors: Baie Xavier , Dessard Vincent , Escoffier René , Laplace Fabien , Picun Gonzalo 
Published: May 2016

Abstract
In this paper, a compact isolated and self-supplied single channel driver module for operation at 200C (392F) is presented. It is aimed to drive a normally-on GaN device within a high voltage half bridge topology. The driver is implemented on a compact hybrid module. Two of such modules are then assembled on a dedicated half-bridge DBC with two GaN devices.