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The implementation of advanced multi-level modulation schemes such as quadrature phase-shift keying (QPSK) in contrast to the conventional on–off keying is crucial to further boost the terahertz (THz) communications speed. Thereby, carrier phase noise reduction in the THz range is one of the key goals that need to be urgently achieved. In this paper, the photonic-based THz sources and the phase noise problem are briefly summarized. Then, a low phase-noise photonic source based on the stimulated Brillouin scattering (SBS) optical fiber cavity is first applied for a 300-GHz-band QPSK wireless communication link. The highest data rate at forward-error-correction limited condition was 15 Gbaud utilizing the SBS-based photonic source with a small transmit power of ~ −36 dBm. Its transmission characteristics are evaluated and compared with the conventional optical frequency comb generator (OFCG)-based source at 5 Gbaud. The proposed SBS-based photonic source has been proven to offer better performances than the OFCG-based source with respect to the phase noise, optical carrier to noise ratio, and bit error rate in communications.
Parotid gland carcinoma is a rare and complicated histopathological classification. Therefore, assembling a sufficient number of cases with long-term outcomes in a single institute can present a challenge.
The medical records of 108 parotid gland carcinoma patients who were treated at Kyushu University Hospital, Fukuoka, Japan, between 1983 and 2014 were reviewed. The survival outcomes were analysed according to clinicopathological findings.
Forty-six patients had low clinical stage tumours (I–II), and 62 patients had high clinical stage tumours (III–IV). Fifty-two, 10 and 46 patients had low-, intermediate- and high-grade tumours, respectively. Twenty-seven of 65 cases had positive surgical margins. In high clinical stage and intermediate- to high-grade tumours, adjuvant radiation therapy was correlated with local recurrence-free survival (p = 0.0244). Intermediate- to high-grade tumours and positive surgical margins were significantly associated with disease-specific survival in multivariate analysis (p = 0.0002 and p = 0.0058).
The results of this study show that adjuvant radiation therapy is useful for improved local control in patients with high clinical stage and intermediate- to high-grade tumours.
To identify the predictive and prognostic factors associated with ampicillin-resistant enterococcal bacteraemia, we retrospectively reviewed demographic, microbiological and clinical data of patients attending the Kyoto University Hospital, Japan, between 2009 and 2015. Logistic regression and Cox regression analyses were performed to determine the predictive and prognostic factors, respectively. In total, 235 episodes of enterococcal bacteraemia were identified. As ampicillin susceptibility was uniform for Enterococcus faecalis isolates and almost all ampicillin-resistant isolates were E. faecium, bacteraemia due to these species was investigated separately. E. faecalis and E. faecium accounted for 41.7% (98/235) and 48.1% (113/235) of the isolates, respectively and 91.2% of all E. faecium were ampicillin resistant. Nosocomial E. faecium bacteraemia acquisition (odds ratio (OR), 13.6; 95% confidence intervals, 3.16–58.3) was associated with ampicillin-resistant isolates. Bacteraemia from an unknown source (hazard ratio (HR), 2.91; 95% CI 1.36–6.21) and an increased Pitt bacteraemia score (PBS) (HR, 1.36; 95% CI 1.21–1.52) were associated with 30-day mortality in E. faecium infections. Likewise, bacteraemia from an unknown source (HR, 4.17; 95% CI 1.25–13.9) and increased PBS (HR, 1.27; 95% CI 1.09–1.48) were associated with 30-day mortality in patients with E. faecalis bacteraemia. The empirical therapeutic administration of glycopeptides is recommended for patients with bacteraemia from an unknown source in whom severe E. faecium bacteraemia is suspected.
It is thought that protoplanets formed in protoplanetary disks excite the orbital motion of the surrounding planetesimals, and the bow shocks caused by the highly excited planetesimals heat their icy component evaporating into gas. We have performed model calculations to study the evolution of molecular abundances of the evaporated icy component, which suggests sulfur-bearing molecules can be good tracers of icy planetesimal evaporation. Here we report the result of our ALMA observations of sulfur-bearing molecules towards protoplanetary disks. The lines were undetected but the obtained upper limits of the line fluxes and our model calculations give upper limits of the fractional abundances of x(H2S) < 10−11 and x(SO) < 10−10 in the outer disk. These results are consistent with the molecular abundances in comets in our Solar system.
Insufficient nutrition during the perinatal period causes structural alterations in humans and experimental animals, leading to increased vulnerability to diseases in later life. Japanese quail, Coturnix japonica, in which partial (8–10%) egg white was withdrawn (EwW) from eggs before incubation had lower birth weights than controls (CTs). EwW birds also had reduced hatching rates, smaller glomeruli and lower embryo weight. In EwW embryos, the surface condensate area containing mesenchymal cells was larger, suggesting that delayed but active nephrogenesis takes place. In mature EwW quail, the number of glomeruli in the cortical region (mm2) was significantly lower (CT 34.7±1.4, EwW 21.0±1.2); capillary loops showed focal ballooning, and mesangial areas were distinctly expanded. Immunoreactive cell junction proteins, N-cadherin and podocin, and slit diaphragms were clearly seen. With aging, the mesangial area and glomerular size continued to increase and were significantly larger in EwW quail, suggesting compensatory hypertrophy. Furthermore, apoptosis measured by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling analysis was higher in EwWs than in CTs on embryonic day 15 and postnatal day 4 (D4). Similarly, plasma glucocorticoid (corticosterone) was higher (P<0.01) on D4 in EwW quail. These results suggest that although nephrogenic activity is high in low-nutrition quail during the perinatal period, delayed development and increased apoptosis may result in a lower number of mature nephrons. Damaged or incompletely mature mesangium may trigger glomerular injury, leading in later life to nephrosclerosis. The present study shows that birds serve as a model for ‘fetal programming,’ which appears to have evolved phylogenetically early.
To verify the effectiveness and safety of the addition of adipose-derived regenerative cells to autologous fat injection therapy.
Unilateral vocal fold paralysis models were made by cutting the right recurrent laryngeal nerve in two pigs. At day 30, 0.5 ml adipose-derived regenerative cells mixed with 1 ml autologous fat was injected into the right vocal fold of one pig, with the other receiving 0.5 ml Ringer's solution mixed with 1 ml autologous fat. At day 120, fibrescopy, laser Doppler flowmeter, computed tomography, vocal function evaluation and histological assessment were conducted.
Although histological assessment revealed atrophy of the thyroarytenoid muscle fibre in both pigs, there was remarkable hypertrophy of the thyroarytenoid muscle fibre in the area surrounding the adipose-derived regenerative cells injection site.
The addition of a high concentration of adipose-derived regenerative cells to autologous fat injection therapy has the potential to improve the treatment outcome for unilateral vocal fold paralysis.
Hyalinizing clear cell carcinoma is a rare minor salivary gland neoplasm. The treatment of choice is surgical resection with or without post-operative radiotherapy. This tumour often demonstrates a good prognosis.
We report a case of hyalinizing clear cell carcinoma arising in the nasopharynx. A 27-year-old female presented with progressive hearing disturbance and tinnitus. On examination, an expansile mass was observed in her nasopharynx. Biopsy was performed and the pathology results returned as clear cell carcinoma.
Results and conclusion:
Surgical resection was performed trans-orally accompanied by trans-palatal approach. She has no recurrence during more than two years of follow up.
We have investigated the effect of oxygen pressure during growth (PO2) on the electronic and magnetic properties of PrAlO3 films grown on TiO2-terminated SrTiO3 substrates. The films are smooth, with flat terraces. Resistivity measurements show an increase in the sheet resistance as PO2 is increased from 10–3 to 10–4 torr, with an usual peak as a function of temperature for the sample grown in higher oxygen pressure. We measured a moderate positive magnetoresistance (MR) at low magnetic fields that evolves into a larger negative MR at high fields, for both PO2 samples. Hall effect data exhibit a complex temperature dependence that suggests a compensated carrier density. We observe behavior consistent with two different types of carriers at each of the two different interfaces.
Zinc oxide thin films prepared by sol-gel and doped with different aluminum percentages were deposited by spray-pyrolysis deposition techniques on FTO and ITO substrates. The films were applied as the sensitive layer of pH-sensors EGFET devices. ZnO:Al films on FTO substrates shows a decrease in sensor quality with the dopant percentage increase. The opposite occurs when the substrate was ITO. The best quality film to be used as pH-sensor on FTO substrates was the ZnO:Al (3%) with 29 mV/pH sensitivity value and linear adjust of 0.99. For ITO substrates the best quality was achieved for ZnO:Al (10%), with sensitivity about 30 mV/pH and 0.99 linear adjust.
Ca2MnO4 nanoparticles were prepared by the Pechini method and acid treated to extract Ca2+ ions. Structural, morphological and spectroscopic analyses by XRD, SEM/EDX, TEM/EDS and Raman revealed the formation of an amorphous outer layer at the particles surface with a preserved inner crystalline bulk. Thanks to the outer layer, which is electrochemically active, the acid-treated compounds showed capacity up to 150 Ah/kg. The crystalline bulk improved cycling stability, allowing reaching capacity retention up to 70% after 30 cycles.
The paper presents complex research of the structure and electrophysical properties of thin films on the basis of Cr2O3, V2O5 and SiO2 oxides compounds. The paper studies binary compounds films of Cr2O3 -V2O5 and Cr2O3 - V2O5 -SiO2 films. The method of electron-beam evaporation is used for the films deposition; glass is used as the substrate. The films structure is studied by the methods of slow electron diffraction, infrared spectroscopy, and electron paramagnetic resonance. The films composition is determined by the X-ray microanalysis.
In the course of studies the following regularities have been established:
- dependence of the films structure on their composition;
- dependence of electrophysical films properties on the their composition;
- dependence of volt-ampere characteristics on the films composition (memory effect);
- high film stability to the effect of electron flow and radiation in the discharge plasma.
ZnO nanorods were synthesized by recrystallization of ZnO thin films during multiannealing process. It was found that the obtained ZnO nanorods showed well-controlled grown direction. The periodical oxygen introducing between reducing annealing processes was effective to help on the oxidization reaction, result in the ZnO nanorods growth significantly. With controlling the annealing parameters, the morphologies of ZnO nanorods could be also controlled. The low-temperature (less than 420°C) initial reducing annealing process contributed to control the density of ZnO nanorods. The multi-annealing processes could reduce the ZnO thin film to produce ZnO nanorods efficiently. The structural, optical and electrical properties of the ZnO nanorods were investigated. Finally, the obtained ZnO nanorods used as photoelectrodes demonstrated in a dye-sensitized solar cell, the overall conversion efficiency of 3.65% was achieved.
VO2 is one of the very few natural materials that can be used to modulate terahertz (THz) radiations. A 100-nm thick VO2, when in its metallic phase, has a charge density of more than ∼ 1015 cm-2 which will strongly reflect and absorb the THz radiation; while in its insulator state, the charge density is lowered by several orders of magnitude to be THz transparent. Therefore, exploiting the metal-insulator transition of VO2 is a potential approach to modulate or even switch THz radiation for THz optics. Here we report that VO2 epitaxial thin films on sapphire substrate exhibits 85% amplitude modulation depth in a broad bandwidth, while this value can be improved to 95% when VO2 film is coated on both sides of a substrate. We further demonstrate that with wafer bonding, 4-layered VO2 thin films exhibit a transmittance as low as -20 dB to -30 dB at their metallic state, enough for switching applications. We also report our proof-of-concept demonstration of THz spatial light modulator that exhibits amplitude modulation as large as 96%, -30 dB pixel-to-pixel crosstalk, and a broad THz bandwidth.
Although the presence of oxygen reservoir is assumed in many theoretical models which explain resistive switching of ReRAM with an electrode/metal oxide (MO)/electrode structure, the location of oxygen reservoir is not clear. We have previously reported a method for preparing an extremely small ReRAM cell which has removable bottom electrode (BE), by using AFM cantilever. In this study, we used this cell structure to specify the location of oxygen reservoir. Since an anode is assumed to work as an oxygen reservoir in most models, we investigated the effect of changing anodes for the same filament on the presence or absence of the occurrence of reset switching. It was revealed that reset occurred independently of catalytic ability and Gibbs free energy (ΔG) of anode material. However, reset was caused by repairing oxygen vacancies of which filament consists when metals with high ΔG is used as an anode, whereas by oxidizing an anode when metals with low ΔG is used as an anode. This result suggests that the MO film works as an oxygen reservoir for anode with high ΔG, whereas an anode works as an oxygen reservoir for anode with low ΔG.
Transparent conducting thin-films of SnO2: F were grown on preheated glass, Al2O3 coated glass, and quartz substrates by Streaming Process for Electrodeless Electrochemical Deposition (SPEED). Stannic chloride (SnCl4) and ammonium fluoride (NH4F) dissolved in a mixture of deionized water and organic solvents were used as precursors. The preheated substrate temperature was varied between 440 and 500 °C. High quality SnO2:F films were grown at all the substrate temperatures studied. The resulting typical film thickness was 250 nm. X-ray diffraction shows that the grown films are polycrystalline SnO2 with a tetragonal crystal structure. The average optical transmission of the films was around 93% throughout the wavelength range 400 to 1000 nm. The lowest electrical resistivity achieved was 6 × 10-4 Ω-cm. The Hall measurements showed that the film is an n-type semiconductor, with carrier mobility of 8.3 cm2/V-s, and carrier concentration of 1 × 1021 cm-3. The direct bandgap was determined to be 4.0 eV from the transmittance spectrum.