563 research outputs found

    Inferior alveolar nerve injury with laryngeal mask airway: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The incidence of damage to the individual cranial nerves and their branches associated with laryngeal mask airway use is low; there have been case reports of damage to the lingual nerve, hypoglossal nerve and recurrent laryngeal nerve. To the best of our knowledge we present the first reported case of inferior alveolar nerve injury associated with laryngeal mask airway use.</p> <p>Case presentation</p> <p>A 35-year-old Caucasian man presented to our facility for elective anterior cruciate ligament repair. He had no background history of any significant medical problems. He opted for general anesthesia over a regional technique. He was induced with fentanyl and propofol and a size 4 laryngeal mask airway was inserted without any problems. His head was in a neutral position during the surgery. After surgery in the recovery room, he complained of numbness in his lower lip. He also developed extensive scabbing of the lower lip on the second day after surgery. The numbness and scabbing started improving after a week, with complete recovery after two weeks.</p> <p>Conclusion</p> <p>We report the first case of vascular occlusion and injury to the inferior alveolar nerve, causing scabbing and numbness of the lower lip, resulting from laryngeal mask airway use. This is an original case report mostly of interest for anesthetists who use the laryngeal mask airway in day-to-day practice. Excessive inflation of the laryngeal mask airway cuff could have led to this complication. Despite the low incidence of cranial nerve injury associated with the use of the laryngeal mask airway, vigilant adherence to evidence-based medicine techniques and recommendations from the manufacturer's instructions can prevent such complications.</p

    Six Months of Multi-Wavelength Follow-up of the Tidal Disruption Candidate ASASSN-14li and Implied TDE Rates from ASAS-SN

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    We present ground-based and Swift photometric and spectroscopic observations of the candidate tidal disruption event (TDE) ASASSN-14li, found at the center of PGC 043234 (d90d\simeq90 Mpc) by the All-Sky Automated Survey for SuperNovae (ASAS-SN). The source had a peak bolometric luminosity of L1044L\simeq10^{44} ergs s1^{-1} and a total integrated energy of E7×1050E\simeq7\times10^{50} ergs radiated over the 6\sim6 months of observations presented. The UV/optical emission of the source is well-fit by a blackbody with roughly constant temperature of T35,000T\sim35,000 K, while the luminosity declines by roughly a factor of 16 over this time. The optical/UV luminosity decline is broadly consistent with an exponential decline, Let/t0L\propto e^{-t/t_0}, with t060t_0\simeq60 days. ASASSN-14li also exhibits soft X-ray emission comparable in luminosity to the optical and UV emission but declining at a slower rate, and the X-ray emission now dominates. Spectra of the source show broad Balmer and helium lines in emission as well as strong blue continuum emission at all epochs. We use the discoveries of ASASSN-14li and ASASSN-14ae to estimate the TDE rate implied by ASAS-SN, finding an average rate of r4.1×105 yr1r \simeq 4.1 \times 10^{-5}~{\rm yr}^{-1} per galaxy with a 90% confidence interval of (2.217.0)×105 yr1(2.2 - 17.0) \times 10^{-5}~{\rm yr}^{-1} per galaxy. ASAS-SN found roughly 1 TDE for every 70 Type Ia supernovae in 2014, a rate that is much higher than that of other surveys.Comment: 21 pages, 9 figures, 6 tables. Photometric data presented in this submission are included as ancillary files. Manuscript updated to reflect changes made in the published version. For a brief video explaining this paper, see https://youtu.be/CTbr-d7cWZ

    SN 2016coi (ASASSN-16fp): an energetic H-stripped core-collapse supernova from a massive stellar progenitor with large mass loss

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    We present comprehensive observations and analysis of the energetic H-stripped SN 2016coi (a.k.a. ASASSN-16fp), spanning the γ\gamma-ray through optical and radio wavelengths, acquired within the first hours to \sim420 days post explosion. Our campaign confirms the identification of He in the SN ejecta, which we interpret to be caused by a larger mixing of Ni into the outer ejecta layers. From the modeling of the broad bolometric light curve we derive a large ejecta mass to kinetic energy ratio (Mej47MM_{\rm{ej}}\sim 4-7\,\rm{M_{\odot}}, Ek78×1051ergE_{\rm{k}}\sim 7-8\times 10^{51}\,\rm{erg}). The small [\ion{Ca}{ii}] \lam\lam7291,7324 to [\ion{O}{i}] \lam\lam6300,6364 ratio (\sim0.2) observed in our late-time optical spectra is suggestive of a large progenitor core mass at the time of collapse. We find that SN 2016coi is a luminous source of X-rays (LX>1039ergs1L_{X}>10^{39}\,\rm{erg\,s^{-1}} in the first 100\sim100 days post explosion) and radio emission (L8.5GHz7×1027ergs1Hz1L_{8.5\,GHz}\sim7\times 10^{27}\,\rm{erg\,s^{-1}Hz^{-1}} at peak). These values are in line with those of relativistic SNe (2009bb, 2012ap). However, for SN 2016coi we infer substantial pre-explosion progenitor mass-loss with rate M˙(12)×104Myr1\dot M \sim (1-2)\times 10^{-4}\,\rm{M_{\odot}yr^{-1}} and a sub-relativistic shock velocity vsh0.15cv_{sh}\sim0.15c, in stark contrast with relativistic SNe and similar to normal SNe. Finally, we find no evidence for a SN-associated shock breakout γ\gamma-ray pulse with energy Eγ>2×1046ergE_{\gamma}>2\times 10^{46}\,\rm{erg}. While we cannot exclude the presence of a companion in a binary system, taken together, our findings are consistent with a massive single star progenitor that experienced large mass loss in the years leading up to core-collapse, but was unable to achieve complete stripping of its outer layers before explosion.Comment: Submitted to ApJ. Main text: 21 pages; Appendix: 15 pages; 12 figure

    Discovery and Observations of ASASSN-13db, an EX Lupi-Type Accretion Event on a Low-Mass T Tauri Star

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    We discuss ASASSN-13db, an EX Lupi-type ("EXor") accretion event on the young stellar object (YSO) SDSS J051011.01-032826.2 (hereafter SDSSJ0510) discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN). Using archival photometric data of SDSSJ0510 we construct a pre-outburst spectral energy distribution (SED) and find that it is consistent with a low-mass class II YSO near the Orion star forming region (d420d \sim 420 pc). We present follow-up photometric and spectroscopic observations of the source after the ΔV\Delta V \sim-5.4 magnitude outburst that began in September 2013 and ended in early 2014. These data indicate an increase in temperature and luminosity consistent with an accretion rate of 107\sim10^{-7} M\rm{M}_\odot yr1^{-1}, three or more orders of magnitude greater than in quiescence. Spectroscopic observations show a forest of narrow emission lines dominated by neutral metallic lines from Fe I and some low-ionization lines. The properties of ASASSN-13db are similar to those of the EXor prototype EX Lupi during its strongest observed outburst in late 2008.Comment: 14 pages, 4 figures, 1 table. Updated May 2014 to reflect changes in the final version published in ApJL. Photometric data presented in this submission are included as ancillary files. For a brief video explaining this paper, see http://youtu.be/yRCCrNJnvt

    The Young and Bright Type Ia Supernova ASASSN-14lp: Discovery, Early-Time Observations, First-Light Time, Distance to NGC 4666, and Progenitor Constraints

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    On 2014 Dec. 9.61, the All-Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin") discovered ASASSN-14lp just 2\sim2 days after first light using a global array of 14-cm diameter telescopes. ASASSN-14lp went on to become a bright supernova (V=11.94V = 11.94 mag), second only to SN 2014J for the year. We present prediscovery photometry (with a detection less than a day after first light) and ultraviolet through near-infrared photometric and spectroscopic data covering the rise and fall of ASASSN-14lp for more than 100 days. We find that ASASSN-14lp had a broad light curve (Δm15(B)=0.80±0.05\Delta m_{15}(B) = 0.80 \pm 0.05), a BB-band maximum at 2457015.82±0.032457015.82 \pm 0.03, a rise time of 16.940.10+0.1116.94^{+ 0.11 }_{- 0.10 } days, and moderate host--galaxy extinction (E(BV)host=0.33±0.06E(B-V)_{\textrm{host}} = 0.33 \pm 0.06). Using ASASSN-14lp we derive a distance modulus for NGC 4666 of μ=30.8±0.2\mu = 30.8 \pm 0.2 corresponding to a distance of 14.7±1.514.7 \pm 1.5 Mpc. However, adding ASASSN-14lp to the calibrating sample of Type Ia supernovae still requires an independent distance to the host galaxy. Finally, using our early-time photometric and spectroscopic observations, we rule out red giant secondaries and, assuming a favorable viewing angle and explosion time, any non-degenerate companion larger than 0.34Rsun0.34 R_{\textrm{sun}}.Comment: 12 pages, 9 figures, 4 tables. Accepted to ApJ. Photometric data presented in this submission are included as an ancillary file. For a brief video explaining this paper, see https://www.youtube.com/watch?v=1bOV-Cqs-a

    Discovery and Early Evolution of ASASSN-19bt, the First TDE Detected by TESS

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    We present the discovery and early evolution of ASASSN-19bt, a tidal disruption event (TDE) discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d115d\simeq115 Mpc and the first TDE to be detected by TESS. As the TDE is located in the TESS Continuous Viewing Zone, our dataset includes 30-minute cadence observations starting on 2018 July 25, and we precisely measure that the TDE begins to brighten 8.3\sim8.3 days before its discovery. Our dataset also includes 18 epochs of Swift UVOT and XRT observations, 2 epochs of XMM-Newton observations, 13 spectroscopic observations, and ground data from the Las Cumbres Observatory telescope network, spanning from 32 days before peak through 37 days after peak. ASASSN-19bt thus has the most detailed pre-peak dataset for any TDE. The TESS light curve indicates that the transient began to brighten on 2019 January 21.6 and that for the first 15 days its rise was consistent with a flux t2\propto t^2 power-law model. The optical/UV emission is well-fit by a blackbody SED, and ASASSN-19bt exhibits an early spike in its luminosity and temperature roughly 32 rest-frame days before peak and spanning up to 14 days that has not been seen in other TDEs, possibly because UV observations were not triggered early enough to detect it. It peaked on 2019 March 04.9 at a luminosity of L1.3×1044L\simeq1.3\times10^{44} ergs s1^{-1} and radiated E3.2×1050E\simeq3.2\times10^{50} ergs during the 41-day rise to peak. X-ray observations after peak indicate a softening of the hard X-ray emission prior to peak, reminiscent of the hard/soft states in X-ray binaries.Comment: 23 pages, 14 figures, 5 tables. A machine-readable table containing the host-subtracted photometry presented in this manuscript is included as an ancillary fil

    ASASSN-15lh: A Highly Super-Luminous Supernova

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    We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of M_{u,AB} = -23.5+/-0.1 and bolometric luminosity L_bol = (2.2+/-0.2)x 10^45 ergs s^-1, which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (M_K ~ -25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1+/- 0.2)x10^52 ergs, challenging the magnetar model for its engine.Comment: Published in the January 15, 2016 Issue of Science Magazin
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