Thyroid surgery for elderly patients: Are they at increased operative risks?

published_or_final_versio

Studying the effect of sonographic landmarks imaged on transcutaneous laryngeal ultrasonography on perioperative vocal cord assessment

Scientific Session 8INTRODUCTION: Transcutaneous laryngeal ultrasound (TLUSG) is a non-invasive way of assessing vocal cord (VC) function. During examination, the assessor often looks at 3 sonographic landmarks (namely, false VC (FC), true VC (TC) and arytenoids (AR)) to ascertain VC movement. However, it is unclear among these landmarks, which one provides the most reliable VC assessment as not all patients would have all three landmarks identified on the same examination. We postulated that perhaps finding all three sonographic landmarks may further improve diagnostic accuracy. To address these questions, we prospectively evaluated consecutive patients over two institutions …published_or_final_versio

A prospective, assessor-blind evaluation of surgeon-performed transcutaneous laryngeal ultrasonography in vocal cord examination before and after thyroidectomy

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A systematic review and meta-analysis of prophylactic central neck dissection on short-term locoregional recurrence in papillary thyroid carcinoma after total thyroidectomy

postprin

Is vocal cord asymmetry seen on transcutaneous laryngeal ultrasonography a significant predictor of voice quality changes after thyroidectomy?

Background: Vocal cord asymmetry (VCA) on laryngoscopic examination (LE) may suggest voice impairment after thyroidectomy, but LE may cause patient discomfort. We aimed to correlate the presence of postoperative VCA assessed by noninvasive transcutaneous laryngeal ultrasonography (TLUSG) with voice quality changes after thyroidectomy. Methods: A total of 169 patients scheduled for thyroidectomy completed two validated voice symptoms questionnaires - the GRBAS (grade, roughness, breathiness, asthenia, strain) scale and the voice impairment score (VIS) - and underwent TLUSG and LE at 1 day before and 7-10 days after thyroidectomy. Postoperative VCA was apparent in 51 patients on TLUSG (group I), whereas there was no VCA in the other 118 patients (group II, controls). The GRBAS scale and VIS results were compared between the groups. Results: Before operation, the two groups had comparable preoperative GRBAS and VIS status. After operation, the "grade" and "roughness" components on the GRBAS scale were significantly worse in group I than in group II: 0.24 versus 0.07 (p = 0.016) and 0.33 versus 0.14 (p = 0.022), respectively. "Grade" and "roughness" in the GRBAS scale significantly worsened after the operation in group I: from 0.04 to 0.24 (p = 0.008) and from 0.02 to 0.33 (p = 0.001), respectively. They did not change in group II. Also, the overall VIS was significantly worse after thyroidectomy in group I: 4.97 versus 12.97 (p < 0.001). Conclusions: VCA seen on TLUSG significantly correlated with "grade" and "roughness" components on the GRBAS scale and the overall VIS. Thus, VCA might be used as a surrogate of postoperative voice changes. © 2013 Société Internationale de Chirurgie.postprin

Quantum Graphs II: Some spectral properties of quantum and combinatorial graphs

The paper deals with some spectral properties of (mostly infinite) quantum and combinatorial graphs. Quantum graphs have been intensively studied lately due to their numerous applications to mesoscopic physics, nanotechnology, optics, and other areas. A Schnol type theorem is proven that allows one to detect that a point belongs to the spectrum when a generalized eigenfunction with an subexponential growth integral estimate is available. A theorem on spectral gap opening for ``decorated'' quantum graphs is established (its analog is known for the combinatorial case). It is also shown that if a periodic combinatorial or quantum graph has a point spectrum, it is generated by compactly supported eigenfunctions (``scars'').Comment: 4 eps figures, LATEX file, 21 pages Revised form: a cut-and-paste blooper fixe

Quasi-particle interference and superconducting gap in a high-temperature superconductor Ca2-xNaxCuO2Cl2

High-transition-temperature (high-Tc) superconductivity is ubiquitous in the cuprates containing CuO2 planes but each cuprate has its own character. The study of the material dependence of the d-wave superconducting gap (SG) should provide important insights into the mechanism of high-Tc. However, because of the 'pseudogap' phenomenon, it is often unclear whether the energy gaps observed by spectroscopic techniques really represent the SG. Here, we report spectroscopic imaging scanning tunneling microscopy (SI-STM) studies of nearly-optimally-doped Ca2-xNaxCuO2Cl2 (Na-CCOC) with Tc = 25 ~ 28 K. They enable us to observe the quasi-particle interference (QPI) effect in this material, through which unambiguous new information on the SG is obtained. The analysis of QPI in Na-CCOC reveals that the SG dispersion near the gap node is almost identical to that of Bi2Sr2CaCu2Oy (Bi2212) at the same doping level, while Tc of Bi2212 is 3 times higher than that of Na-CCOC. We also find that SG in Na-CCOC is confined in narrower energy and momentum ranges than Bi2212. This explains at least in part the remarkable material dependence of TcComment: 13pages, 4fig

Imaging the Two Gaps of the High-TC Superconductor Pb-Bi2Sr2CuO6+x

The nature of the pseudogap state, observed above the superconducting transition temperature TC in many high temperature superconductors, is the center of much debate. Recently, this discussion has focused on the number of energy gaps in these materials. Some experiments indicate a single energy gap, implying that the pseudogap is a precursor state. Others indicate two, suggesting that it is a competing or coexisting phase. Here we report on temperature dependent scanning tunneling spectroscopy of Pb-Bi2Sr2CuO6+x. We have found a new, narrow, homogeneous gap that vanishes near TC, superimposed on the typically observed, inhomogeneous, broad gap, which is only weakly temperature dependent. These results not only support the two gap picture, but also explain previously troubling differences between scanning tunneling microscopy and other experimental measurements.Comment: 6 page

Prostate cancer stem cells

Despite the discovery over 60 years ago by Huggins and Hodges 1 that prostate cancers respond to androgen deprivation therapy, hormone-refractory prostate cancer remains a major clinical challenge. There is now mounting evidence that solid tumours originate from undifferentiated stem cell-like cells coexisting within a heterogeneous tumour mass that drive tumour formation, maintain tumour homeostasis and initiate metastases. This review focuses upon current evidence for prostate cancer stem cells, addressing the identification and properties of both normal and transformed prostate stem cells

Collective emotions online and their influence on community life

E-communities, social groups interacting online, have recently become an object of interdisciplinary research. As with face-to-face meetings, Internet exchanges may not only include factual information but also emotional information - how participants feel about the subject discussed or other group members. Emotions are known to be important in affecting interaction partners in offline communication in many ways. Could emotions in Internet exchanges affect others and systematically influence quantitative and qualitative aspects of the trajectory of e-communities? The development of automatic sentiment analysis has made large scale emotion detection and analysis possible using text messages collected from the web. It is not clear if emotions in e-communities primarily derive from individual group members' personalities or if they result from intra-group interactions, and whether they influence group activities. We show the collective character of affective phenomena on a large scale as observed in 4 million posts downloaded from Blogs, Digg and BBC forums. To test whether the emotions of a community member may influence the emotions of others, posts were grouped into clusters of messages with similar emotional valences. The frequency of long clusters was much higher than it would be if emotions occurred at random. Distributions for cluster lengths can be explained by preferential processes because conditional probabilities for consecutive messages grow as a power law with cluster length. For BBC forum threads, average discussion lengths were higher for larger values of absolute average emotional valence in the first ten comments and the average amount of emotion in messages fell during discussions. Our results prove that collective emotional states can be created and modulated via Internet communication and that emotional expressiveness is the fuel that sustains some e-communities.Comment: 23 pages including Supporting Information, accepted to PLoS ON