bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of ceramic B4C particulate addition on tensile behavior of 6061 aluminum matrix
Authors: Rajagopal Sandeep Panyam , Lakshmikantha Rajesh Gandasi , Virupaxi Auradi , Amarappa Kori Shivputrappa 
Published: February 2016

Abstract
In this study, an attempt was made to prepare 6061Al – B4Cp composites through a two-step melt stirring process at 750 °C. During the preparation of the composite, preheated K2TiF6 flux along with B4Cp (ratio 0.08) was added in the melt in two steps to avoid segregation of B4CP. Microstructural characterization was done using scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction techniques. Density, hardness and tensile strength of the cast alloy and the composite were determined both at room temperature and 100 °C. Fracture studies of the tensile specimens were also done using scanning electron microscopy.
Experimental investigation by atomic force microscopy on mechanical and tribological properties of thin films
Authors: Birleanu Corina , Pustan Marius , Müller Raluca , Dudescu Cristian , Merie Violeta , Voicu Rodica , Baracu Angela 
Published: February 2016

Abstract
For this paper, a two part approach was taken to develop a fundamental understanding of the surface properties of four different hard thin films. On one front, atomic force microscopy was used to quantitatively measure both the adhesion and friction forces between the tip and sample surfaces. On the other front, the indentation technique was used to determine the mechanical properties of these materials (Young's modulus and hardness). The main purpose of this study was to investigate different thin films deposited on silicon wafer substrate for improving the wear life and reducing the coefficient of friction. Nanomechanical and nanotribological characterization of thin films of chromium, nickel, platinum and titanium deposited on silicon were performed.
Clinical outcomes after percutaneous transforaminal endoscopic discectomy for lumbar disc herniation: a prospective case series
Authors: Gadjradj Pravesh S. , van Tulder Maurits W. , Dirven Clemens M. F. , Peul Wilco C. , Harhangi B. Sanjay 
Published: February 2016

OBJECTIVE
Throughout the last decades, full-endoscopic techniques to treat lumbar disc herniation (LDH) have gained popularity in clinical practice. To date, however, no Class I evidence on the efficacy of percutaneous transforaminal endoscopic discectomy (PTED) has been published, and studies describing its safety and short- and long-term efficacy are scarce. In this study the authors aimed to evaluate the clinical outcomes and safety in patients undergoing PTED for LDH.

METHODS
Patients who underwent PTED for LDH between January 2009 and December 2012 were prospectively followed. The primary outcomes were the visual analog scale (VAS) score for leg pain and the score on the Quebec Back Pain Disability Scale (QBPDS). Secondary outcomes were the perceived experience with the local anesthesia used and satisfaction with the results after 1 year using Likert-type scales. The pretreatment means were compared with the means obtained 6 and 52 weeks after surgery using paired t-tests.

RESULTS
A total of 166 patients underwent surgery for a total of 167 LDHs. The mean duration of surgery (± SD) was 51.0 ± 9.0 minutes. The 1-year follow-up rate was 95.2%. The mean reported scores on the VAS and QBPDS were 82.5 ± 17.3 mm and 60.0 ± 18.4 at baseline, respectively. Six weeks after surgery, the scores on the VAS and QBPDS were significantly reduced to 28.8 ± 24.5 mm and 26.7 ± 20.6, respectively (p < 0.001). After 52 weeks of follow-up, the scores were further reduced compared with baseline scores (p < 0.001) to 19.6 ± 23.5 mm on the VAS and 20.2 ± 18.1 on the QBPDS. A total of 4 complications were observed, namely 1 dural tear, 1 deficit of ankle dorsiflexion, and 2 cases of transient paresis in the foot due to the use of local anesthetics.

CONCLUSIONS
PTED appears to be a safe and effective intervention for LDH and has similar clinical outcomes compared to conventional open microdiscectomy. High-quality randomized controlled trials are required to study the efficacy and cost-effectiveness of PTED.
Patient radiation exposure during transforaminal lumbar endoscopic spine surgery: a prospective study
Authors: Iprenburg Menno , Wagner Ralf , Godschalx Alexander , Telfeian Albert E. 
Published: February 2016

OBJECTIVE
The aim of this study was to describe patient radiation exposure during single-level transforaminal endoscopic lumbar discectomy procedures at levels L2–5 and L5–S1.

METHODS
Radiation exposure was monitored in 151 consecutive patients undergoing single-level transforaminal endoscopic lumbar discectomy procedures. Two groups were studied: patients undergoing procedures at the L4–5 level or above and those undergoing an L5–S1 procedure.

RESULTS
For the discectomy procedures at L4–5 and above, the average duration of fluoroscopy was 38.4 seconds and the mean calculated patient radiation exposure dose was 1.5 mSv. For the L5–S1 procedures, average fluoroscopy time was 54.6 seconds and the mean calculated radiation exposure dose was 2.1 mSv. The average patient radiation exposure dose among these cases represents a 3.5-fold decrease compared with the senior surgeon's first 100 cases.

CONCLUSIONS
Transforaminal lumbar endoscopic discectomy can be used as a minimally invasive technique for the treatment of lumbar radiculopathy in the setting of a herniated lumbar disc without the significant concern of exposing the patient to harmful doses of radiation. One caveat is that both the surgeon and the patient are likely to be exposed to higher doses of radiation during a surgeon's early experience in minimally invasive endoscopic spine surgery.
The endoscopic transoral approach to the craniovertebral junction: an anatomical study with a clinical example
Authors: Chan Andrew K. , Benet Arnau , Ohya Junichi , Zhang Xin , Vogel Todd D. , Flis Daniel W. , El-Sayed Ivan H. , Mummaneni Praveen V. 
Published: February 2016

OBJECTIVE
The microscopic transoral, endoscopic transnasal, and endoscopic transoral approaches are used alone and in combination for a variety of craniovertebral junction (CVJ) pathologies. The endoscopic transoral approach provides a more direct exposure that is not restricted by the nasal cavity, pterygoid plates, and palate while sparing the potential morbidities associated with extensive soft-tissue dissection, palatal splitting, or mandibulotomy. Concerns regarding the extent of visualization afforded by the endoscopic transoral approach may be limiting its widespread adoption.

METHODS
A dissection of 10 cadaver heads was undertaken. CT-based imaging guidance was used to measure the working corridor of the endoscopic transoral approach. Measurements were made relative to the palatal line. The built-in linear measurement tool was used to measure the superior and inferior extents of view. The superolateral extent was measured relative to the midline, as defined by the nasal process of the maxilla. The height of the clivus, odontoid tip, and superior aspect of the C-1 arch were also measured relative to the palatal line. A correlated clinical case is presented with video.

RESULTS
The CVJ was accessible in all cases. The superior extent of the approach was a mean 19.08 mm above the palatal line (range 11.1–27.7 mm). The superolateral extent relative to the midline was 15.45 mm on the right side (range 9.6–23.7 mm) and 16.70 mm on the left side (range 8.1–26.7 mm). The inferior extent was a mean 34.58 mm below the palatal line (range 22.2–41.6 mm). The mean distances were as follows: palatal line relative to the odontoid tip, 0.97 mm (range −4.9 to 3.7 mm); palatal line relative to the height of the clivus, 4.88 mm (range −1.5 to 7.3 mm); and palatal line relative to the C-1 arch, −2.75 mm (range −5.8 to 0 mm).

CONCLUSIONS
The endoscopic transoral approach can reliably access the CVJ. This approach avoids the dissections and morbidities associated with a palate-splitting technique (velopharyngeal insufficiency) and the expanded endonasal approach (mucus crusting, sinusitis, and potential lacerum or cavernous-paraclival internal carotid artery injury). For appropriately selected lesions near the palatal line, the endoscopic transoral approach appears to be the preferred approach.
Early experience with endoscopic foraminotomy in patients with moderate degenerative deformity
Authors: Madhavan Karthik , Chieng Lee Onn , McGrath Lynn , Hofstetter Christoph P. , Wang Michael Y. 
Published: February 2016

OBJECTIVE
Asymmetrical degeneration of the disc is one of the most common causes of primary degenerative scoliosis in adults. Coronal deformity is usually less symptomatic than a sagittal deformity because there is less expenditure of energy and hence less effort to maintain upright posture. However, nerve root compression at the fractional curve or at the concave side of the main curve can give rise to debilitating radiculopathy.

METHODS
This study was a retrospective analysis of 16 patients with coronal deformity of between 10° and 20°. All patients underwent endoscopic foraminal decompression surgery. The pre- and postoperative Cobb angle, visual analog scale (VAS), 36-Item Short Form Health Survey (SF-36), and Oswestry Disability Index scores were measured.

RESULTS
The average age of the patients was 70.0 ± 15.5 years (mean ± SD, range 61–86 years), with a mean followup of 7.5 ± 5.3 months (range 2–14 months). The average coronal deformity was 16.8° ± 4.7° (range 10°–41°). In 8 patients the symptomatic foraminal stenosis was at the level of the fractional curve, and in the remaining patients it was at the concave side of the main curve. One of the patients included in the current cohort had to undergo a repeat operation within 1 week for another disc herniation at the adjacent level. One patient had CSF leakage, which was repaired intraoperatively, and no further complications were noted. On average, preoperative VAS and SF-36 scores showed a tendency for improvement, whereas a dramatic reduction of VAS, by 65% (p = 0.003), was observed in radicular leg pain.

CONCLUSIONS
Patients with mild to moderate spinal deformity are often compensated and have tolerable levels of back pain. However, unilateral radicular pain resulting from foraminal stenosis can be debilitating. In select cases, an endoscopic discectomy or foraminotomy enables the surgeon to decompress the symptomatic foramen with preservation of essential biomechanical structures, delaying the need for a major deformity correction surgery.
Transforaminal endoscopic discectomy to relieve sciatica and delay fusion in a 31-year-old man with pars defects and low-grade spondylolisthesis
Authors: Madhavan Karthik , Chieng Lee Onn , Hofstetter Christoph P. , Wang Michael Y. 
Published: February 2016

Isthmic spondylolisthesis due to pars defects resulting from trauma or spondylolysis is not uncommon. Symptomatic patients with such pars defects are traditionally treated with a variety of fusion surgeries. The authors present a unique case in which such a patient was successfully treated with endoscopic discectomy without iatrogenic destabilization.
A 31-year-old man presented with a history of left radicular leg pain along the distribution of the sciatic nerve. He had a disc herniation at L5/S1 and bilateral pars defects with a Grade I spondylolisthesis. Dynamic radiographic studies did not show significant movement of L-5 over S-1. The patient did not desire to have a fusion. After induction of local anesthesia, the patient underwent an awake transforaminal endoscopic discectomy via the extraforaminal approach, with decompression of the L-5 and S-1 nerve roots. His preoperative pain resolved immediately, and he was discharged home the same day. His preoperative Oswestry Disability Index score was 74, and postoperatively it was noted to be 8. At 2-year follow-up he continued to be symptom free, and no radiographic progression of the listhesis was noted.
In this case preservation of stabilizing structures, including the supraspinous and interspinous ligaments and the facet capsule, may have reduced the likelihood of iatrogenic instability while at the same time achieving symptom control. This may be a reasonable option for select patient symptoms confined to lumbosacral radiculopathy.
MOTION VERIFIED RED STARS (MoVeRS): A CATALOG OF PROPER MOTION SELECTED LOW-MASS STARS FROM WISE, SDSS, AND 2MASS
Authors: Theissen Christopher A. , West Andrew A. , Dhital Saurav 
Published: February 2016

ABSTRACT
We present a photometric catalog of 8,735,004 proper motion selected low-mass stars (KML-spectral types) within the Sloan Digital Sky Survey (SDSS) footprint, from the combined SDSS Data Release 10 (DR10), Two Micron All-Sky Survey (2MASS) point-source catalog (PSC), and Wide-field Infrared Survey Explorer (WISE) AllWISE catalog. Stars were selected using r − i, i − z, r − z, z − J, and z − W1 colors, and SDSS, WISE, and 2MASS astrometry was combined to compute proper motions. The resulting 3,518,150 stars were augmented with proper motions for 5,216,854 earlier type stars from the combined SDSS and United States Naval Observatory B1.0 catalog (USNO-B). We used SDSS+USNO-B proper motions to determine the best criteria for selecting a clean sample of stars. Only stars whose proper motions were greater than their 2σ uncertainty were included. Our Motion Verified Red Stars catalog is available through SDSS CasJobs and VizieR.
RADIO PROPERTIES OF YOUNG STELLAR OBJECTS IN THE CORE OF THE SERPENS SOUTH INFRARED DARK CLOUD
Authors: Kern Nicholas S. , Keown Jared A. , Tobin John J. , Mead Adrian , Gutermuth Robert A. 
Published: February 2016

ABSTRACT
We present deep radio continuum observations of the star-forming core of the Serpens South Infrared Dark Cloud with the Karl G. Jansky Very Large Array. Observations were conducted in two bands centered at 7.25 GHz (4.14 cm) and 4.75 GHz (6.31 cm) with a

of 8.5 and 11.1 μJy/beam, respectively. We also use 2MASS, Spitzer and Herschel data to put our radio observations in the context of young stellar populations characterized by near and far-infrared observations. Within a 5′ × 5′ region of interest around the central cluster, we detect roughly eighteen radio sources, seven of which we determine are protostellar in nature due to their radio spectral indices and their association with infrared sources. We find evidence for a previously undetected embedded Class 0 protostar and reaffirm Class 0 protostellar classifications determined by previous millimeter wavelength continuum studies. We use our infrared data to derive mid-infrared luminosities for three of our protostellar sources and find relative agreement between the known young stellar object (YSO) radio luminosity versus bolometric luminosity correlation. Lastly, we marginally detect an additional six radio sources at the 2–3σ level that lie within two arcseconds of infrared YSO candidates, providing motivation for higher sensitivity studies to clarify the nature of these sources and further probe embedded and/or low luminosity YSOs in Serpens South.
HIDDEN MOLECULES IN PLANETARY NEBULAE: NEW DETECTIONS OF HCN AND HCO+ FROM A MULTI-OBJECT SURVEY
Authors: Schmidt D. R. , Ziurys L. M. 
Published: February 2016

ABSTRACT
Searches for HCN and HCO+ have been conducted toward 17 planetary nebulae (PNs) in the age range 800 to 13,000 years using the facilities of the Arizona Radio Observatory (ARO). For both molecules, observations of the

transition near 88–89 GHz were carried out with the ARO 12 m, including measurements with the new ALMA prototype antenna, while the

lines near 265–267 GHz were sought with the ARO Sub-Millimeter Telescope (SMT). HCN and HCO+ were newly detected in 13 of the 17 target sources in at least one transition. Nine PNs were common to both molecules: Hb5, K3-17, K3-58, M1-7, M4-14, M3-28, M3-55, NGC 2440, and K4-47, while HCO+ was also identified in K3-83 and M2-9, and HCN in K3-45 and NGC 6772. From radiative transfer modeling, column densities for HCN and HCO+ in these sources were determined to be

∼ 0.2–27 × 1013 cm−2 and

∼ 0.3–8.7 × 1013 cm−2. Gas densities, assumed to be in clumped regions, were established to be n(H2) ∼ 0.1–5.2 × 106 cm−3. Fractional abundances, relative to H2, for both molecules were found to be f(HCN) ∼ 0.1–9.1 × 10−7 and f(HCO+) ∼ 0.04–7.4 × 10−7. The abundances of both species were found to remain relatively constant with nebular age over a 10,000 year time span, in contrast to predictions of chemical models. The HCN/HCO+ ratio varied from 17 to <0.2, and roughly correlates with the C/O ratio. Polyatomic molecules appear to be common constituents of PNs.
DYNAMIC SPECTRAL MAPPING OF INTERSTELLAR PLASMA LENSES
Authors: Tuntsov Artem V. , Walker Mark A. , Koopmans Leon V. E. , Bannister Keith W. , Stevens Jamie , Johnston Simon , Reynolds Cormac , Bignall Hayley E. 
Published: February 2016

ABSTRACT
Compact radio sources sometimes exhibit intervals of large, rapid changes in their flux density, due to lensing by interstellar plasma crossing the line of sight. A novel survey program has made it possible to discover these “Extreme Scattering Events” (ESEs) in real time, resulting in a high-quality dynamic spectrum of an ESE observed in PKS 1939–315. Here we present a method for determining the column-density profile of a plasma lens, given only the dynamic radio spectrum of the lensed source, under the assumption that the lens is either axisymmetric or totally anisotropic. Our technique relies on the known, strong frequency dependence of the plasma refractive index in order to determine how points in the dynamic spectrum map to positions on the lens. We apply our method to high-frequency (4.2–10.8 GHz) data from the Australia Telescope Compact Array of the PKS 1939–315 ESE. The derived electron column-density profiles are very similar for the two geometries we consider, and both yield a good visual match to the data. However, the fit residuals are substantially above the noise level, and deficiencies are evident when we compare the predictions of our model to lower-frequency (1.6–3.1 GHz) data on the same ESE, thus motivating future development of more sophisticated inversion techniques.
OBSERVATIONAL EVIDENCE FOR THE RELATIONSHIP BETWEEN WALÉN SLOPE AND AMPLITUDE RATIO OF INWARD TO OUTWARD ALFVÉN WAVES IN THE SOLAR WIND
Authors: Yang L. , Lee L. C. , Chao J. K. , Hsieh W. C. , Luo Q. Y. , Li J. P. , Shi J. K. , Wu D. J. 
Published: February 2016

ABSTRACT
Assuming that the observed Alfvén waves in the solar wind are the superposition of inward- and outward-propagating Alfvén waves, we obtain an analytical relation from which the observed Walén slope R
W can give a theoretical estimate of the amplitude ratio

of inward to outward waves. From the Wind data at 1 AU, we select 37 Alfvén wave events classified observationally as three kinds: dominant outward Alfvén waves with

(Class A), dominant outward Alfvén waves with

(Class B), and dominant inward Alfvén waves with

(Class C). For Class A events the theoretical predictions of

based on R
W deviate from the wave amplitude observations, but for Class B and C events the theoretical predictions agree well with related observations, being a direct observational evidence that the superposition of inward and outward Alfvén waves can cause the subunity of R
W. A simple simulation is made with a white Gaussian noise to demonstrate that a small noise could reproduce the observed properties of all three kinds of events cause the measured parameters of waves with

in Class A to deviate significantly from the true values more than waves with

. The simulation implies that the observational results based on wave amplitudes seem reliable only for waves with

. The

ratios calculated from the analytical relation based on R
W are closer to true values than those obtained from wave amplitude observations.
HERBIG Ae/Be CANDIDATE STARS IN THE INNERMOST GALACTIC DISK: QUARTET CLUSTER
Authors: Yasui Chikako , Kobayashi Naoto , Hamano Satoshi , Kondo Sohei , Izumi Natsuko , Saito Masao , Tokunaga Alan T. 
Published: February 2016

ABSTRACT
In order to investigate the Galactic-scale environmental effects on the evolution of protoplanetary disks, we explored the near-infrared (NIR) disk fraction of the Quartet cluster, which is a young cluster in the innermost Galactic disk at the Galactocentric radius

. Because this cluster has a typical cluster mass of ∼103

as opposed to very massive clusters, which have been observed in previous studies (>104

), we can avoid intra-cluster effects such as strong UV field from OB stars. Although the age of the Quartet is previously estimated to be 3–8 Myr old, we find that it is most likely ∼3–4.5 Myr old. In moderately deep JHK images from the United Kingdom Infrared Telescope Infrared Deep Sky Survey, we found eight HAeBe candidates in the cluster, and performed K-band medium-resolution (

) spectroscopy for three of them with the Subaru 8.2 m telescope. These are found to have both Brγ absorption lines as well as CO bandhead emission, suggesting that they are HAeBe stars with protoplanetary disks. We estimated the intermediate-mass disk fraction (IMDF) to be ∼25% for the cluster, suggesting slightly higher IMDF compared to those for young clusters in the solar neighborhood with similar cluster age, although such a conclusion should await future spectroscopic study of all candidates of cluster members.
DETECTING THE SUPERNOVA BREAKOUT BURST IN TERRESTRIAL NEUTRINO DETECTORS
Authors: Wallace Joshua , Burrows Adam , Dolence Joshua C. 
Published: February 2016

ABSTRACT
We calculate the distance-dependent performance of a few representative terrestrial neutrino detectors in detecting and measuring the properties of the ν

e
breakout burst light curve in a Galactic core-collapse supernova. The breakout burst is a signature phenomenon of core collapse and offers a probe into the stellar core through collapse and bounce. We examine cases of no neutrino oscillations and oscillations due to normal and inverted neutrino-mass hierarchies. For the normal hierarchy, other neutrino flavors emitted by the supernova overwhelm the ν

e
signal, making a detection of the breakout burst difficult. For the inverted hierarchy (IH), some detectors at some distances should be able to see the ν

e
breakout burst peak and measure its properties. For the IH, the maximum luminosity of the breakout burst can be measured at 10 kpc to accuracies of ∼30% for Hyper-Kamiokande (Hyper-K) and ∼60% for the Deep Underground Neutrino Experiment (DUNE). Super-Kamiokande (Super-K) and Jiangmen Underground Neutrino Observatory (JUNO) lack the mass needed to make an accurate measurement. For the IH, the time of the maximum luminosity of the breakout burst can be measured in Hyper-K to an accuracy of ∼3 ms at 7 kpc, in DUNE to ∼2 ms at 4 kpc, and JUNO and Super-K can measure the time of maximum luminosity to an accuracy of ∼2 ms at 1 kpc. Detector backgrounds in IceCube render a measurement of the ν

e
breakout burst unlikely. For the IH, a measurement of the maximum luminosity of the breakout burst could be used to differentiate between nuclear equations of state.