Structure determination in a new type of amorphous molecular solids with different nonlinear optical properties: a comparative structural analysis.

The microscopic structures of two amorphous molecular solids with extremely nonlinear optical properties have been studied. They consist of organotetrel chalcogenide clusters with the chemical formula [(RSn)4S6]. The basic molecular building blocks are adamantane-like {Sn4S6} cores with organic ligands R attached to the Sn atoms. While the material equipped with R=naphthyl generates frequency doubling upon irradiation with a simple infrared laser diode, the material decorated with R=phenyl responds by emitting brilliant white light. The structural differences were investigated using x-ray scattering and extended x-ray absorption fine structure combined with molecular Reverse Monte Carlo. Transmission electron microscopy and scanning precession electron diffraction were used to examine structural differences from mesoscopic down to microscopic scales. Characteristic differences were found on all scales. While close core-to-core distances between {Sn4S6} cluster cores and molecular distortions are found in the white light emitting material, undistorted molecules and significantly larger core distances characterize the material showing frequency doubling. Here however, results of scanning precession electron diffraction reveal the formation of nanocrystalline structures in the amorphous matrix, which we identify as cause for the suppression of white light emission.

Structural origins of the unusual thermal stability of amorphous CuxGe50-xTe50(0⩽x⩽33.3).

We have investigated the local atomic structures of several compositions of the amorphous phase of the system CuxGe50-xTe50(0⩽x⩽33.3), based on extended x-ray absorption fine-structure as well as anomalous x-ray scattering experiments, and discuss the unusual trend regarding their thermal stability as a function of the Cu content. At low concentrations (x⩽15), Cu atoms tend to agglomerate in flat nanoclusters reminiscent of the crystalline phase of metallic Cu, leading to a more and more Ge-deficient Ge-Te host network structure with growing Cu content and an increasing thermal stability. At higher Cu concentrations (x⩾25), Cu is incorporated into the network, leading to an overall weaker bonding situation which is associated with a decreasing thermal stability.

Collective excitations in a melt of fast phase change material GeCu2Te3.

Inelastic x-ray scattering measurements have been carried out to investigate atomic dynamics in a melt of fast phase change material GeCu2Te3. The dynamic structure factor was analysed using the model function with three damped harmonic oscillator components. By investigating the correlation between the excitation energy and the linewidth, and that between the excitation energy and the intensity on contour maps of a relative approximate probability distribution function proportional toexp(-χ2/N), we could judge the reliability of each inelastic excitation in the dynamic structure factor. The results indicate that there are two inelastic excitation modes besides the longitudinal acoustic one in the liquid. The lower energy excitation could be assigned to the transverse acoustic one whereas the higher energy one disperses like fast sound. The latter result may imply that the liquid ternary alloy exhibits a microscopic phase separation tendency.

Low energy excitation in liquid Sb and liquid Bi observed in inelastic x-ray scattering spectra.

The dynamic structure factorS(Q,E), whereQandEare momentum and energy transfer, respectively, has been measured for liquid Sb, using inelastic x-ray scattering. A modified damped harmonic oscillator model function was applied to analyseS(Q,E) of liquid Sb and also to that of liquid Bi by Inuiet al(2015Phys. Rev.B92, 054206). The obtained excitation energy was in fairly good agreement with that predicted byab initiomolecular dynamics simulations on these liquid semi-metals. The excitation energy of the longitudinal acoustic mode in liquid Sb and liquid Bi exhibits flat-toppedQdependence whereas the lower excitation energy below the longitudinal acoustic excitation showsQ-gap behaviour. From the viscosity estimated from theQ-gap experimentally obtained, it is inferred that the lower energy excitation arises from the transverse acoustic excitation in the liquids.

Collective particle dynamics of molten NaCl by inelastic x-ray scattering.

An inelastic x-ray scattering experiment has been performed on molten NaCl over wide wave vector and energy transfer ranges. Data of high statistical quality are analyzed using a memory function approach within a generalized Langevin equation. The approach with two relaxation times for the memory function provides a very good data description over the whole wave vector range beyond the hydrodynamic regime. A slow thermal and a fast structural relaxation process in the memory function completely define the density fluctuations in molten NaCl and evidences the thermal-viscoelastic model as the minimal description for collective particle dynamics in molten alkali halides. The obtained excitation frequencies demonstrate a large positive dispersion effect, which can be related to the viscoelastic reaction of the molten salt. A transition from the viscoelastic to a hydrodynamic response of the molten salt at small wave vectors is observed. In the hydrodynamic regime the resulting thermal diffusivity agrees well with values obtained through light scattering. The modeling indicates some deficiencies at small wave vectors and large energy transfers and the spectra of the current correlation function evidences additional intensity at high frequency. The frequency of these additional modes approach a non-zero value at zero wave vector and indicates a non-acoustic character of these excitations. The frequency center of this additional inelastic intensity coincides with optic-type modes in molten NaCl predicted by simulations.

Relevance of level IIb neck dissection in patients with papillary thyroid carcinoma.

BACKGROUND: Cervical nodal metastasis is a key prognostic factor in patients with papillary thyroid carcinoma. The role of lymph nodes in papillary thyroid carcinoma management and prognosis remains controversial. METHODS: Level IIb lymph nodes obtained from 44 patients with papillary thyroid carcinoma were histopathologically examined retrospectively. Specimens were classified as ipsilateral or contralateral. The number of dissected nodes and prevalence of level IIb metastasis were compared according to pre-operative clinical nodal stage. RESULTS: In the node-negative neck, the prevalence of contralateral and ipsilateral IIb nodes was 0 out of 20 and 0 out of 3, respectively. In the node-positive neck, the prevalence of contralateral and ipsilateral IIb nodes was 1 out of 13 (7.70 per cent) and 3 out of 41 (7.32 per cent), respectively. Clinically determined and pathologically confirmed level IIb node negativity were significantly associated. Thirty-four patients (77.3 per cent) developed accessory nerve complications from level IIb dissection. CONCLUSION: Level IIb neck dissection for papillary thyroid carcinoma may be required if pre-operative examination reveals multilevel, level IIa or suspicious level IIb metastasis.

Peculiar temperature dependence of dynamical sound speed in liquid Se50Te50 by inelastic x-ray scattering.

Inelastic x-ray scattering (IXS) measurements were carried out on liquid Se50Te50 at temperatures up to 1323 K to investigate how the atomic dynamics changes with temperature through the semiconductor-metal transition. The acoustic mode was clearly observed in the dynamic structure factor and its energy was determined using a damped harmonic oscillator model. The dynamical sound speed obtained by IXS for [Formula: see text] nm-1 was found to behave similarly to the temperature dependence of ultrasonic sound velocity with a minimum near the semiconductor metal transition. The results can be explained by taking liquid Se50Te50 to be an inhomogeneous liquid consisting of metallic and semiconducting domains whose size is approximately 3 nm. The relaxation time obtained from frequency dependence of the dynamical sound speed was on a picosecond time scale.

Emergent thyroidectomy with sternotomy due to acute respiratory failure with severe thyroid storm.

Huge cervical and mediastinal masses may lead to acute respiratory failure caused by laryngotracheal compression and airway obstruction. Thyroid storm is also a life-threatening endocrine emergency originating almost exclusively from uncontrolled Graves' disease. We report a case of a 42-year-old man with acute upper airway obstruction and tachycardia from progressive swelling of a giant thyroid, in conjunction with thyroid storm resulting from uncontrolled Graves' disease. Fibreoptic-assisted nasal intubation was performed while the patient was awake, immediately followed by emergency total thyroidectomy via a cervical and sternal approach. The patient had an uneventful postoperative course and recovered well. Respiratory failure due to swelling of a giant thyroid is a life-threatening condition and should be treated immediately with endotracheal intubation while the patient is awake following emergent total thyroidectomy, even with a sternotomy.

Static and dynamic structures of liquid Ba8Ga16Sn30: a melt of the thermoelectric clathrate compounds.

X-ray diffraction and inelastic x-ray scattering measurements of liquid Ba8Ga16Sn30 have been carried out to investigate local structure and atomic dynamics in the liquid. The pair distribution function shows shorter and longer interatomic distances in the first coordination shell. The dynamic structure factor exhibits the inelastic excitations on both sides of the quasielastic central peak. The inelastic excitations disperse with increasing the momentum transfer, suggesting the longitudinal acoustic mode. We found a low energy excitation in addition to the longitudinal acoustic excitation in the dynamic structure factor and it reminds us a strong relationship with a rattling motion of a guest (Ba) atom in the solid state. The temperature dependence of the pair distribution function and the longitudinal acoustic excitation energy is very weak in a range from 600 to 900 °C. The result suggests that Ba and other atoms in the melt are located around minimum positions of the effective pair potential approximated as a harmonic one.

Viscoelastic anomaly accompanying anti-crossing behaviour in liquid As2Se3.

We investigate the dynamic structure factor of the melt of the well known glass former, As2Se3, using inelastic x-ray scattering for temperatures, T, [Formula: see text] K and momentum transfers Q from [Formula: see text] nm-1. An anomaly was observed at Q = 2.7 nm-1 ([Formula: see text] K) with, in the context of a simple model, both an abrupt change in frequency and an increased linewidth reminiscent of an anti-crossing in a solid. Comparison with structural information from reverse Monte Carlo modeling of x-ray diffraction data allows us to associate the disappearance of the anomaly at higher temperatures with a drop in the number of mechanical constraints per atom, n mc, to [Formula: see text] reminiscent of the threshold applicable for glass formation in rigidity theory. It is inferred that the surprising jump in the dispersion in the liquid may be correlated with a stiffness transition in a network glass.

Visible light-induced water splitting in an aqueous suspension of a plasmonic Au/TiO2 photocatalyst with metal co-catalysts.

We found that plasmonic Au particles on titanium(iv) oxide (TiO2) act as a visible-light-driven photocatalyst for overall water splitting free from any additives. This is the first report showing that surface plasmon resonance (SPR) in a suspension system effectively induces overall water splitting. Modification with various types of metal nanoparticles as co-catalysts enhanced the evolution of H2 and O2. Among these, Ni-modified Au/TiO2 exhibited 5-times higher rates of H2 and O2 evolution than those of Ni-free Au/TiO2. We succeeded in designing a novel solar energy conversion system including three elemental technologies, charge separation with light harvest and an active site for O2 evolution (plasmonic Au particles), charge transfer from Au to the active site for H2 production (TiO2), and an active site for H2 production (Ni cocatalyst), by taking advantage of a technique for fabricating size-controlled Au and Ni nanoparticles. Water splitting occurred in aqueous suspensions of Ni-modified Au/TiO2 even under irradiation of light through an R-62 filter.

Prognostic factors for idiopathic sudden sensorineural hearing loss treated with hyperbaric oxygen therapy and intravenous steroids.

OBJECTIVE: This study evaluated the prognosis of idiopathic sudden sensorineural hearing loss when treated with hyperbaric oxygen therapy and intravenous steroids. METHODS: The clinical data for 334 patients with idiopathic sudden sensorineural hearing loss treated by hyperbaric oxygen therapy and intravenous steroids at our hospital were retrospectively reviewed. These data included the initial averaged five-frequency hearing level, patient age, interval between onset of symptoms and treatment, vertigo as a complication, and co-existence of diabetes mellitus. RESULTS: The overall improvement rate was 69.2 per cent, including better improvement (25.5 per cent), good improvement (21.0 per cent) and fair improvement (22.7 per cent). CONCLUSION: Hyperbaric oxygen therapy appears to confer a significant additional therapeutic benefit when used in combination with steroid therapy for idiopathic sudden sensorineural hearing loss. If performed early, hyperbaric oxygen therapy may bring about hearing improvement in many patients who are unresponsive to initial therapy.

Survival outcomes after surgical resection of pulmonary metastases of head and neck tumours.

BACKGROUND: There is limited information available regarding the benefits and outcomes of resection of pulmonary metastases arising from head and neck cancers. METHODS: A retrospective review was performed of 21 patients who underwent resection of pulmonary metastases of primary head and neck malignancies at Hamamatsu University Hospital. Clinical staging, treatment methods, pathological subtype (particularly squamous cell carcinoma), disease-free interval and overall survival were evaluated. RESULTS: The 5- and 10-year overall survival rates of the study participants were 67.0 per cent and 55.0 per cent, respectively, as determined by the Kaplan-Meier method. The prognosis for patients with a disease-free interval of less than 24 months was poor compared to those with a disease-free interval of greater than 24 months (p = 0.0234). CONCLUSION: Patients with short disease-free intervals, and possibly those who are older than 60 years, should be categorised as having severe disease. However, pulmonary metastases from head and neck malignancies are potentially curable by surgical resection.

Transverse excitations in liquid Fe, Cu and Zn.

Transverse acoustic (TA) excitation modes were observed in inelastic x-ray scattering spectra of liquid Fe, Cu and Zn. From the analysis of current correlation functions, we concluded that TA excitation modes can experimentally be detected through the quasi-TA branches in the longitudinal current correlation spectra in these liquid metals. The microscopic elastic constants are estimated and a characteristic difference from macroscopic polycrystalline value was found in Poisson's ratio of liquid Fe, which shows an extremely softer value of ∼0.38 compared with the macroscopic value of ∼0.275. The lifetime of the TA modes were determined to be ∼0.45 ps for liquid Fe and Cu and ∼0.55 ps for liquid Zn, reflecting different interatomic correlations between liquid transition metals and non-transition metals. The propagation length of the TA modes are ∼0.85 nm in all of liquid metals, corresponding to the size of icosahedral or similar size of cages formed instantaneously in these liquid metals.

Toxoplasma lymphadenitis diagnosed by fine-needle aspiration cytology: a rare finding.

BACKGROUND: There are only very few reports of cervical toxoplasma lymphadenitis being diagnosed exclusively via fine-needle aspiration cytology (with serology). CASE REPORT: We describe a case of toxoplasma lymphadenitis that was successfully diagnosed by fine-needle aspiration cytology. The case involved a male patient who was immunocompromised as a result of recurrent acute myelogenous leukaemia with cervical lymphadenopathy. The biopsy showed typical features of a well-defined pseudocyst containing Toxoplasma gondii tachyzoites. CONCLUSION: Toxoplasma lymphadenitis is a common cause of lymph node enlargement. Fine-needle aspiration cytology is a useful method for diagnosing and differentiating toxoplasma lymphadenitis from more serious causes of lymphadenopathy, such as metastatic lymphadenopathy or lymphoma.

Carcinoma of the external auditory canal: histological and treatment groups.

OBJECTIVE: Evaluation of the clinical and pathological factors associated with the treatment and outcomes of external auditory canal (EAC) carcinomas. METHODOLOGY: A retrospective review of clinical and pathological analysis was performed on 23 patients who were histologically diagnosed with EAC carcinomas and treated at Hamamatsu University hospital. We evaluated the clinical staging, treatment methods, pathological diagnosis (particularly squamous cell carcinoma, SCC), and patient outcomes. Main outcome measures include staging, treatment procedures, pathological features, and estimated survival rates. RESULTS: The 5-year overall survival (OS) of study participants was 75.2% and the 10-year OS was 60.2% using the Kaplan-Meier method. The prognosis for SCC was poor compared with other carcinomas (p= 0.0462). The prognoses for SCC patients after treatment with surgery alone and after postoperative radiotherapy or chemoradiotherapy were significantly better than for patients with unresectable tumours (p = 0.0004 and p = 0.0001, respectively). There was no significant difference among the four tumour stage groups. Information about patients' survival status was obtained after a median follow-up period of 57.5 months (range, 7-151 months). CONCLUSION: Our survival analysis data for carcinoma of the EAC demonstrates that SCC and unresectable cases are associated with poor outcomes. Outcomes for patients with operable disease more closely parallel the survival curves of patients with advanced stage T4 disease. Patients with SCC should be strictly categorized as cases with severe disease.

Transverse excitations in liquid Sn.

Transverse acoustic (TA) excitation modes were observed in inelastic x-ray scattering (IXS) spectra of liquid Sn. The excitation energies and widths of the TA modes are in good agreement with results of an ab initio molecular dynamics simulation. By comparing current correlation spectra between the experimental and theoretical results quantitatively, we have concluded that the TA modes can be detected experimentally through the quasi-TA branches in the longitudinal current correlation spectra. The lifetime and propagation length of the TA modes were determined to be ~0.7 ps and 0.8-1.0 nm, respectively, corresponding to the size of cages formed instantaneously in liquid Sn.

Clinical study of mucosa-associated lymphoid tissue lymphomas of the head and neck.

BACKGROUND: Limited information is available on mucosa-associated lymphoid tissue lymphomas arising in the head and neck. METHOD: A retrospective analysis was conducted of 20 patients who were histologically diagnosed with mucosa-associated lymphoid tissue lymphoma and treated at our institution between January 1990 and December 2009. RESULTS: Treatment consisted of surgical resection alone in two patients (10 per cent), surgical resection with consecutive radiotherapy in one (5 per cent), and radiotherapy alone in eight (40 per cent). Three patients (15 per cent) were treated with systemic chemotherapy, and three (15 per cent) received chemoradiotherapy. Three patients (15 per cent) were informed of the diagnosis but not treated for their condition. CONCLUSION: All of the 20 patients were still alive after a mean follow-up period of 50.8 months. Local treatment for mucosa-associated lymphoid tissue lymphoma of the head and neck should be the first choice in early-stage disease. However, prolonged follow up is important to determine these patients' long-term response to treatment.