Postoperative laryngoscopy in thyroid surgery: proper timing to detect recurrent laryngeal nerve injury

BACKGROUND: There is currently a lack of consensus to support the proper timing for postoperative laryngoscopy that is reliable to diagnose recurrent laryngeal nerve palsy (RLNP) after thyroid surgery. The purpose of this study was to investigate the impact of different time intervals of fiber-optic nasolaryngoscopy (FNL) on the diagnosis of RLNP. METHOD: FNL was performed postoperatively at day 0 (T1), at second day post-op (T2), and +2 weeks (T3). For patients with RLNP, repeated examinations were performed at +2 (T4), +6 (T5), and +12 months (T6). RESULTS: Four hundred thirty-four patients appear for postoperative FNL, providing 825 nerves at risk. Permanent RLNP occurred in 0.7%, temporary RLNP in 6.7%. RLNP rate was 6.4% at T1, 6.7% at T2, 4.8% at T3, 2.5% at T4, 0.8% at T5, and 0.7% at T6. Full recovery of vocal cord function was confirmed after rehabilitation in 87.5% of cases at T5 and 89% in T6. T2 was significantly superior to T3 in terms of diagnosis of RLNP (P < 0.05). Of patients at T2, 10.7% did not see any reason to FNL because of their normal voice register. CONCLUSION: FNL is essential for the detection of vocal cord paralysis after thyroidectomy. We report different time evaluation criteria of vocal cord motility with great and significant variability of results. Second day post-op inspection of the larynx (T2) is suggested. Symptomatic voice assessment is insufficient

Optical frequency measurement of the 1S-3S two-photon transition in hydrogen

This article reports the first optical frequency measurement of the $1\mathrm{S}-3\mathrm{S}$ transition in hydrogen. The excitation of this transition occurs at a wavelength of 205 nm which is obtained with two frequency doubling stages of a titanium sapphire laser at 820 nm. Its frequency is measured with an optical frequency comb. The second-order Doppler effect is evaluated from the observation of the motional Stark effect due to a transverse magnetic field perpendicular to the atomic beam. The measured value of the $1\mathrm{S}_{1/2}(F=1)-3\mathrm{S}_{1/2}(F=1)$ frequency splitting is $2 922 742 936.729 (13) \mathrm{MHz}$ with a relative uncertainty of $4.5\times10^{-12}$. After the measurement of the $1\mathrm{S}-2\mathrm{S}$ frequency, this result is the most precise of the optical frequencies in hydrogen

High-resolution microwave frequency dissemination on an 86-km urban optical link

We report the first demonstration of a long-distance ultra stable frequency dissemination in the microwave range. A 9.15 GHz signal is transferred through a 86-km urban optical link with a fractional frequency stability of 1.3x10-15 at 1 s integration time and below 10-18 at one day. The optical link phase noise compensation is performed with a round-trip method. To achieve such a result we implement light polarisation scrambling and dispersion compensation. This link outperforms all the previous radiofrequency links and compares well with recently demonstrated full optical links.Comment: 11 pages, 5 figure

An Optical Lattice Clock with Spin-polarized 87Sr Atoms

We present a new evaluation of an 87Sr optical lattice clock using spin polarized atoms. The frequency of the 1S0-3P0 clock transition is found to be 429 228 004 229 873.6 Hz with a fractional accuracy of 2.6 10^{-15}, a value that is comparable to the frequency difference between the various primary standards throughout the world. This measurement is in excellent agreement with a previous one of similar accuracy

Enzymatic Hydrolysis of Bacterial Cellulose for the Production of Nanocrystals for the Food Packaging Industry

Bacterial cellulose nanocrystals (BCNCs) obtained by enzymatic hydrolysis have been loaded in pullulan biopolymer for use as nanoparticles in the generation of high-oxygen barrier coatings intended for food packaging applications. Bacterial cellulose (BC) produced by Komagataeibacter sucrofermentans was hydrolyzed by two different enzymatic treatments, i.e., using endo-1,4-\u3b2-glucanases (EGs) from Thermobifida halotolerans and cellulase from Trichoderma reesei. The hydrolytic activity was compared by means of turbidity experiments over a period of 145 h, whereas BCNCs in their final state were compared, in terms of size and morphology, by atomic force microscopy (AFM) and dynamic light scattering (DLS). Though both treatments led to particles of similar size, a greater amount of nano-sized particles ( 48250 nm) were observed in the system that also included cellulase enzymes. Unexpectedly, transmission electron microscopy (TEM) revealed that cellulose nanoparticles were round-shaped and made of 4-5 short (150-180 nm) piled whiskers. Pullulan/BCNCs nanocomposite coatings allowed an increase in the overall oxygen barrier performance, of more than two and one orders of magnitude ( 480.7 mL\ub7m-2\ub724 h-1), of pure polyethylene terephthalate (PET) ( 48120 mL\ub7m-2\ub724 h-1) as well as pullulan/coated PET ( 486 mL\ub7m-2\ub724 h-1), with no significant difference between treatments (hydrolysis mediated by EGs or with the addition of cellulase). BCNCs obtained by enzymatic hydrolysis have the potential to generate high oxygen barrier coatings for the food packaging industry