Sunkyung Park

Prevertebral soft tissue swelling after anterior cervical discectomy and fusion with plate fixation

Airway complications after anterior cervical surgery are rare but potentially lethal. The purpose of this study was to identify the natural course of prevertebral soft tissue swelling after one- or two-level anterior cervical discectomy and fusion (ACDF) in order to prevent lethal airway obstruction after ACDF. Eighty-seven patients scheduled for one- or two-level ACDF were studied prospectively. Lateral radiographs of the cervical spine were taken preoperatively, postoperatively on the day of surgery and on the first, second, third, fourth, and fifth days after operation. Prevertebral soft tissue was measured from C2 to C6 on cervical spine lateral radiographs. The anteroposterior (AP) thickness of the prevertebral soft tissue was measured at each cervical level from C2 to C6. Prevertebral soft tissue swelling occurred postoperatively and increased markedly on the second day after operation. The maximum swelling was found on the second and third days. In fusions above C5 swelling was most prominent at C2, 3. Gradual decrease in swelling was observed after the fourth postoperative day. Prominent swelling was noted at the second, third, and fourth cervical levels. There was no significant difference in swelling when comparing one-level and two-level ACDF. Only one patient required reintubation (1.1%). In conclusion, in this prospective study of 87 patients fused at one or two levels in the cervical spine peak prevertebral soft tissue swelling was observed on the second and third days after the surgery.RésuméLes complications aériennes après chirurgie cervicale antérieure sont rares mais potentiellement léthales. Le sujet de ce travail est d’étudier l’évolution de l’œdème prévertébral après discectomie antérieure et fusion à un ou deux niveaux ( ACDF) pour prévenir une obstruction aérienne. 87 patients devant avoir un ACDF a un ou deux niveaux étaient étudiés prospectivement. Des radiographies de profil de la colonne cervicale ont été faites avant l’opération, après l’opération le jour de la chirurgie, puis les premier, deuxième, troisième, quatrième et cinquième jours après. Les parties molles prévertébrales étaient mesurées de C2 à C6 sur ces radiographies. L’œdème prévertébral apparaissait en postopératoire et avait une augmentation marqué le deuxième jour après la chirurgie. Dans les fusions au-dessus de C5 l’œdème prédominait en C2, C3. La régression de l’œdème était observée après le quatrième jour post-opératoire. Un œdème prononcé était noté aux deuxième, troisième et quatrième niveau cervical. Il n’y avait pas de différence significative dans l’oedème en comparant un et deux niveaux de discectomie-fusion. Seulement 1 patient a eu besoin d’une ré-intubation (1,1%). En conclusion , dans cette série, l’acmé de l’œdème prévertébral était observée les deuxième et troisième jours après l’opération.

NEAR-IR PHOTOMETRIC STUDY OF THE FU ORIONIS OBJECT HBC 722

We present near-infrared light curves of HBC 722 after its the September 2010 outburst. We have been monitoring its near-infrared light curves since November 2010 with Korean Astronomy and Space Science Institute Infrared Camera System (KASINICS). HBC 722 exhibits large changes in optical and near-infrared brightness since its outburst. The J, H, and Ks light curves over about 2.5 years show that in all observed bands HBC 722 progressively became fainter until around April 2011, down to J �10.7, H �9.9, Ks �9.3, but it is getting brighter again. Large scatter in the obtained light curve prevents us from finding whether there is any short timescale variation as reported in other optical observations. The near-infrared color of HBC 722 is becoming bluer since its outburst. The pre-outburst Spectral Energy Distribution (SED) of HBC 722 is consistent with that of a slightly reddened Class II YSO with the exception of the extraordinary IR-excess in the far-infrared region.

300 nights of science with IGRINS at McDonald Observatory

The Immersion Grating Infrared Spectrometer (IGRINS) is a revolutionary instrument that exploits broad spectral coverage at high-resolution in the near-infrared. IGRINS employs a silicon immersion grating as the primary disperser, and volume-phase holographic gratings cross-disperse the H and K bands onto Teledyne Hawaii-2RG arrays. The use of an immersion grating facilitates a compact cryostat while providing simultaneous wavelength coverage from 1.45 - 2.5 μm. There are no cryogenic mechanisms in IGRINS and its high-throughput design maximizes sensitivity. IGRINS on the 2.7 meter Harlan J. Smith Telescope at McDonald Observatory is nearly as sensitive as CRIRES at the 8 meter Very Large Telescope. However, IGRINS at R≈45,000 has more than 30 times the spectral grasp of CRIRES* in a single exposure. Here we summarize the performance of IGRINS from the first 300 nights of science since commissioning in summer 2014. IGRINS observers have targeted solar system objects like Pluto and Ceres, comets, nearby young stars, star forming regions like Taurus and Ophiuchus, the interstellar medium, photo dissociation regions, the Galactic Center, planetary nebulae, galaxy cores and super novae. The rich near-infrared spectra of these objects motivate unique science cases, and provide information on instrument performance. There are more than ten submitted IGRINS papers and dozens more in preparation. With IGRINS on a 2.7m telescope we realize signal-to-noise ratios greater than 100 for K=10.3 magnitude sources in one hour of exposure time. Although IGRINS is Cassegrain mounted, instrument flexure is sub-pixel thanks to the compact design. Detector characteristics and stability have been tested regularly, allowing us to adjust the instrument operation and improve science quality. A wide variety of science programs motivate new tools for analyzing high-resolution spectra including multiplexed spectral extraction, atmospheric model fitting, rotation and radial velocity, unique line identification, and circumstellar disk modeling. Here we discuss details of instrument performance, summarize early science results, and show the characteristics of IGRINS as a versatile near-infrared spectrograph and forerunner of future silicon immersion grating spectrographs like iSHELL2 and GMTNIRS.3

HIGH RESOLUTION OPTICAL AND NIR SPECTRA OF HBC 722

We present the results of high resolution (R

IGRINS SPECTROSCOPY OF CLASS I SOURCES: IRAS 03445+3242 AND IRAS 04239+2436

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Direct Spectral Detection: An Efficient Method to Detect and Characterize Binary Systems

30,000) optical and near-IR spectroscopic monitoring observations of HBC 722, a recent FU Orionis object that underwent an accretion burst in 2010. We observed HBC 722 in optical/near-IR with the BOES, HET-HRS, and IGRINS spectrographs, at various points in the outburst. We found atomic lines with strongly blueshifted absorption features or P Cygni profiles, both evidence of a wind driven by the accretion. Some lines show a broad double-peaked absorption feature, evidence of disk rotation. However, the wind-driven and disk-driven spectroscopic features are anti-correlated in time; the disk features became strong as the wind features disappeared. This anti-correlation might indicate that the rebuilding of the inner disk was interrupted by the wind pressure during the first two years. The Half-Width at Half-Depth (HWHD) of the double-peaked profiles decreases with wavelength, indicative of the Keplerian rotation; the optical spectra with the disk feature are fitted by a G5 template stellar spectrum convolved with a rotation velocity of 70 km s

WILSON-BAPPU EFFECT: EXTENDED TO SURFACE GRAVITY

^{-1}

Kinematic evidence for feedback-driven star formation in NGC 1893

while the near-IR disk features are fitted by a K5 template stellar spectrum convolved with a rotation velocity of 50 km s

IGRINS Spectral Library

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BOES Survey of FU Orionis-type Objects

. Therefore, the optical and near-IR spectra seem to trace the disk at 39 and 76