3,435 research outputs found

    A systematic review and meta-analysis comparing surgically-related complications between robotic-assisted thyroidectomy and conventional open thyroidectomy

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    Background: Despite gaining popularity, robotic-assisted thyroidectomy (RT) remains controversial. This systematic review and meta-analysis is aimed at comparing surgically-related complications between RT and conventional open thyroidectomy (OT). Methods: A systematic review of the literature was performed to identify studies comparing surgically-related outcomes between RT and OT. Studies that compared ≥1 surgically-related outcomes between RT and OT were included. Outcomes included operating time, blood loss, complications, and hospital stay. Meta-analysis was performed using a fixed-effects model. Results: Eleven studies were eligible but none were randomized controlled trials. Of the 2,375 patients, 839 (35.3 %) underwent RT, while 1,536 (64.7 %) underwent OT. RT was significantly associated with longer operating time (p < 0.001), hospital stay (p = 0.023) and higher temporary recurrent laryngeal nerve (RLN) injury (p = 0.016). Although there was no correlation between the number of RTs reported in the study and the rate of temporary RLN injury (p = -0.486, p = 0.328, respectively), routine perioperative laryngoscopy was performed in only 2 of 11 studies. Blood loss (p = 0.485), temporary (p = 0.333) and permanent (p = 0.599) hypocalcemia, hematoma (p = 0.602), and overall morbidity (p = 0.880) appeared comparable. Two (0.2 %) brachial plexus injuries in RT were reported in one study. Conclusions: Relative to OT, RT was associated with significantly longer operating time, longer hospital stay, and higher temporary RLN injury rate but comparable permanent complications and overall morbidity. Given some of the limitations with the literature and the potential added surgical risks and morbidity in RT, application of the robot in thyroid surgery should be carefully and thoroughly discussed before one decides on the procedure. © 2013 Society of Surgical Oncology.postprin

    A systematic review and meta-analysis evaluating completeness and outcomes of robotic thyroidectomy

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    OBJECTIVES/HYPOTHESIS: Despite immense interest, robotic-assisted thyroidectomy (RT) remains controversial in differentiated thyroid carcinoma (DTC). This systematic review and meta-analysis compared surgical completeness and/or oncological outcomes between RT and open thyroidectomy (OT) in low-risk DTC. STUDY DESIGN: Systematic review. METHODS: A systematic review was performed to identify studies that compared surgical completeness and/or oncological outcomes between RT and OT in DTC. Any study that compared at least one parameter relating to surgical completeness and/or oncological outcome for DTC was considered. Number of central lymph nodes (CLNs) retrieved during central neck dissection (CND), preablation stimulated thyroglobulin (sTg) level, radioiodine uptake on post-therapy scan, and locoregional recurrence (LRR) were examined. Meta-analysis was performed using a fixed or random-effects model depending on heterogeneity between studies. RESULTS: Ten studies were eligible. Of the 2,205 DTCs, 752 (34.1%) had RT, whereas 1,453 (65.9%) had OT. Relative to OT, RT had signif icantly fewer CLNs retrieved during CND (4.7 ± 3.2 vs. 5.5 ± 3.8, standardized mean difference [SMD] = -0.240, 95% confidence interval [CI]: -0.364 to -0.116, P < .001) and higher preablation sTg level (3.6 ± 6.7 ng/mL vs. 2.0 ± 5.0 ng/mL, SMD = 0.272, 95% CI: 0.022 to 0.522, P = .033). Interestingly, these differences were more evident in the robotic transaxillary approach (RTAA) than the robotic bilateral axillo-breast approach. After a mean follow-up of 17.7 months, no LRR was found in RT, whereas after 18.6 months, one LRR was found in OT. CONCLUSIONS: Relative to OT, total thyroidectomy by RTAA was associated with fewer CLNs retrieved and less-complete thyroid resection. However, using RTAA is unlikely to compromise the outcomes of low-risk DTC because of its inherently good prognosis. Laryngoscope, 125:509-518, 2015. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.postprin

    Motivated proteins: a web application for studying small three-dimensional protein motifs

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    &lt;b&gt;BACKGROUND:&lt;/b&gt; Small loop-shaped motifs are common constituents of the three-dimensional structure of proteins. Typically they comprise between three and seven amino acid residues, and are defined by a combination of dihedral angles and hydrogen bonding partners. The most abundant of these are alphabeta-motifs, asx-motifs, asx-turns, beta-bulges, beta-bulge loops, beta-turns, nests, niches, Schellmann loops, ST-motifs, ST-staples and ST-turns.We have constructed a database of such motifs from a range of high-quality protein structures and built a web application as a visual interface to this. &lt;b&gt;DESCRIPTION:&lt;/b&gt; The web application, Motivated Proteins, provides access to these 12 motifs (with 48 sub-categories) in a database of over 400 representative proteins. Queries can be made for specific categories or sub-categories of motif, motifs in the vicinity of ligands, motifs which include part of an enzyme active site, overlapping motifs, or motifs which include a particular amino acid sequence. Individual proteins can be specified, or, where appropriate, motifs for all proteins listed. The results of queries are presented in textual form as an (X)HTML table, and may be saved as parsable plain text or XML. Motifs can be viewed and manipulated either individually or in the context of the protein in the Jmol applet structural viewer. Cartoons of the motifs imposed on a linear representation of protein secondary structure are also provided. Summary information for the motifs is available, as are histograms of amino acid distribution, and graphs of dihedral angles at individual positions in the motifs. &lt;b&gt;CONCLUSION:&lt;/b&gt; Motivated Proteins is a publicly and freely accessible web application that enables protein scientists to study small three-dimensional motifs without requiring knowledge of either Structured Query Language or the underlying database schem

    Ultra-strong Adhesion of Graphene Membranes

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    As mechanical structures enter the nanoscale regime, the influence of van der Waals forces increases. Graphene is attractive for nanomechanical systems because its Young's modulus and strength are both intrinsically high, but the mechanical behavior of graphene is also strongly influenced by the van der Waals force. For example, this force clamps graphene samples to substrates, and also holds together the individual graphene sheets in multilayer samples. Here we use a pressurized blister test to directly measure the adhesion energy of graphene sheets with a silicon oxide substrate. We find an adhesion energy of 0.45 \pm 0.02 J/m2 for monolayer graphene and 0.31 \pm 0.03 J/m2 for samples containing 2-5 graphene sheets. These values are larger than the adhesion energies measured in typical micromechanical structures and are comparable to solid/liquid adhesion energies. We attribute this to the extreme flexibility of graphene, which allows it to conform to the topography of even the smoothest substrates, thus making its interaction with the substrate more liquid-like than solid-like.Comment: to appear in Nature Nanotechnolog

    Jacobi-Predictor-Corrector Approach for the Fractional Ordinary Differential Equations

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    We present a novel numerical method, called {\tt Jacobi-predictor-corrector approach}, for the numerical solution of fractional ordinary differential equations based on the polynomial interpolation and the Gauss-Lobatto quadrature w.r.t. the Jacobi-weight function ω(s)=(1s)α1(1+s)0\omega(s)=(1-s)^{\alpha-1}(1+s)^0. This method has the computational cost O(N) and the convergent order ININ, where NN and ININ are, respectively, the total computational steps and the number of used interpolating points. The detailed error analysis is performed, and the extensive numerical experiments confirm the theoretical results and show the robustness of this method.Comment: 24 pages, 5 figure

    Search for astronomical neutrinos from blazar TXS 0506+056 in super-kamiokande

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    We report a search for astronomical neutrinos in the energy region from several GeV to TeV in the direction of the blazar TXS 0506+056 using the Super-Kamiokande detector following the detection of a 100 TeV neutrinos from the same location by the IceCube collaboration. Using Super-Kamiokande neutrino data across several data samples observed from 1996 April to 2018 February we have searched for both a total excess above known backgrounds across the entire period as well as localized excesses on smaller timescales in that interval. No significant excess nor significant variation in the observed event rate are found in the blazar direction. Upper limits are placed on the electron- and muon-neutrino fluxes at the 90% confidence level as 6.0 × 10−7 and 4.5 × 10−7–9.3 × 10−10 [erg cm−2 s−1], respectively

    Phosphorescent Energy Downshifting for Diminishing Surface Recombination in Silicon Nanowire Solar Cells

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    Molecularly engineered Ir(III) complexes can transfer energy from short-wavelength photons (lambda &lt; 450 nm) to photons of longer wavelength (lambda &gt; 500 nm), which can enhance the otherwise low internal quantum efficiency (IQE) of crystalline Si (c-Si) nanowire solar cells (NWSCs) in the shortwavelength region. Herein, we demonstrate a phosphorescent energy downshifting system using Ir(III) complexes at short wavelengths (300-450 nm) to diminish the severe surface recombination that occurs in c-Si NWSCs. The developed Ir(III) complexes can be considered promising energy converters because they exhibit superior intrinsic properties such as a high quantum yield, a large Stokes shift, a long exciton diffusion length in crystalline film, and a reproducible synthetic procedure. Using the developed 1011) complexes, highly crystalline energy downshifting layers were fabricated by ultrasonic spray deposition to enhance the photoluminescence efficiency by increasing the radiative decay. With the optimized energy downshifting layer, our 1cm(2) c-Si NWSCs with Ir(III) complexes exhibited a higher IQE value for short-wavelength light (300-450 nm) compared with that of bare Si NWSCs without Ir(III) complexes, resulting in a notable increase in the short-circuit current density (from 34.4 mA.cm(-2) to 36.5 mA.cm(-2) )

    Search for Second-Generation Scalar Leptoquarks in ppˉ\bm{p \bar{p}} Collisions at s\sqrt{s}=1.96 TeV

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    Results on a search for pair production of second generation scalar leptoquark in ppˉp \bar{p} collisions at s\sqrt{s}=1.96 TeV are reported. The data analyzed were collected by the CDF detector during the 2002-2003 Tevatron Run II and correspond to an integrated luminosity of 198 pb1^{-1}. Leptoquarks (LQ) are sought through their decay into (charged) leptons and quarks, with final state signatures represented by two muons and jets and one muon, large transverse missing energy and jets. We observe no evidence for LQLQ production and derive 95% C.L. upper limits on the LQLQ production cross sections as well as lower limits on their mass as a function of β\beta, where β\beta is the branching fraction for LQμqLQ \to \mu q.Comment: 9 pages (3 author list) 5 figure

    Effective Rheology of Bubbles Moving in a Capillary Tube

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    We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur
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