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Our aim was to determine if stapes surgery is useful for treating inflammatory ear diseases.
Materials and methods:
Thirteen patients underwent single-stage or staged surgery for stapes fixation due to tympanosclerosis alone or with cholesteatoma. Operative criteria were: no tympanic membrane retraction, perforation or adhesion; middle-ear cavity with aeration >1 year; a fixed stapes. Computed tomography was used to analyse the relation between operative success and pre-operative pneumatisation.
Success rate at six months was 75 per cent. Hearing results were stable with little deterioration and no complications. Patients with poor pneumatisation had good results (with improved air–bone gap) only after staged surgery. Well-aerated ears heard better even with single-stage surgery.
Pre-operative computed tomography and intra-operative findings are necessary to determine the pneumatisation status of tympanic mastoid cavities. If criteria approved, poorly pneumatised patients underwent staged surgery. Stapedectomy achieved good hearing results for inflammatory middle-ear disease with stapes fixation.
Epithelial ovarian carcinoma (EOC) is the leading cause of cancer-related death in women in Western countries. Once patients experience recurrence, complete cure is almost impossible. We elucidated the effect of nonequilibrium atmospheric pressure plasma on the growth of EOC, particularly in plasma-activated medium (PAM). Furthermore, we examined the role of reactive oxygen species (ROS) or their scavengers in chronic antineoplastic-resistant EOC cells. As a result, we showed PAM induced the antitumor effect of EOC cells in vitro and in vivo, even in chemoresistant cells. To apply the plasma treatment for advanced or recurrent EOC, we suggest adopting indirect plasma therapy instead of direct plasma considering intraperitoneal administration in the future. However, there are several problems under investigation, including intracellular mechanism of antitumor effect by PAM and adverse event in vivo.
Fetal lung maturity assessment in twin pregnancy has been discussed, but is still controversial. The purpose of this study is to predict the occurrence of respiratory distress syndrome (RDS) using lamellar body count (LBC) and analyze the validity of LBC for fetal lung maturity assessment in twin pregnancy. Three-hundred two amniotic fluid samples were obtained at cesarean section from 29 to 38 weeks of gestation. Samples were analyzed immediately with no centrifugation and the number of lamellar bodies was counted using a platelet channel on the Sysmex SF-3000. There were 18 neonates (6.0%) suffering from RDS. An LBC cut-off value of 2.95 × 104/μL resulted in 91.5% sensitivity and 83.3% specificity for predicting RDS. This cut-off value for predicting RDS was the same as that in singleton pregnancy. Moreover, the median LBC value in RDS cases was significantly lower than in non-RDS cases (1.50 ± 1.1 × 104/μL vs. 10.6 ± 7.5 × 104/μL; p < .001). This is the first report on the validity of LBC in twin pregnancy and also the largest study on fetal lung maturity assessment in twin pregnancy. An LBC value of >2.95 × 104/μL means reassuring findings for RDS even in twin pregnancy. We believe the data in this study provide valuable, new information for the management of twin pregnancies.
Two independent ovarian cancer cell lines and fibroblast controls were treated with nonequilibrium atmospheric pressure plasma (NEAPP). Most ovarian cancer cells were detached from the culture dish by continuous plasma treatment to a single spot on the dish. Next, the plasma source was applied over the whole dish using a robot arm. In vitro cell proliferation assays showed that plasma treatments significantly decreased proliferation rates of ovarian cancer cells compared to fibroblast cells. FACS and Western blot analysis showed that plasma treatment of ovarian cancer cells induced apoptosis. NEAPP could be a promising tool for therapy for ovarian cancers.
In this study, we propose copper oxide (CuOx) edge-termination for GaN-based Schottky barrier diodes (SBDs) with low turn-on voltage. CuOx fabricated by thermal oxidization of sputtered Cu film at 275°C consisted mainly of Cu2O which is known as a p-type semiconductor. We applied CuOx edge-termination to GaN SBDs with tantalum (Ta) Schottky electrode which has low work function of 4.25 eV. The experimental results of current-voltage characteristics insisted that CuOx edge-termination structure was effective to increase breakdown voltage of GaN SBDs with keeping low turn-on voltage of 0.29 V at 10 A/cm2.
In this paper, we describe highly reliable GaN high electron mobility transistors (HEMTs) for high-power and high-efficiency amplifiers. First, we present the reliability mechanisms and progress on the previously reported GaN HEMTs. Next, we introduce our specific device structure of GaN HEMTs for improving reliability. An n-GaN cap and optimized buffer layer were used to suppress the trap-related phenomena, such as a current collapse. Gate edge oxidation is effective for reducing the gate leakage current. A Ta-based barrier metal was inserted between an ohmic electrode and interconnection metal for preventing increase in contact resistance. SiN of passivation film was optimized for reducing the current collapse of short-gatelength HEMTs.
Although there is speculation that individuals living in the vicinity of nuclear disasters have persistent mental health deterioration due to psychological stress, few attempts have been made to examine this issue.
To determine whether having been in the vicinity of the Nagasaki atomic bomb explosion in the absence of substantial exposure to radiation affected the mental health of local inhabitants more than half a century later.
Participants were randomly recruited from individuals who lived in the vicinity of the atomic bomb explosion in uncontaminated suburbs of Nagasaki. This sample (n = 347) was stratified by gender, age, perception of the explosion and current district of residence. Controls (n = 288) were recruited from among individuals who had moved into the area from outside Nagasaki 5–15 years after the bombing, matched for gender, age and district of residence. The primary outcome measure was the proportion of those at high risk of mental disorder based on the 28-item version of the General Health Questionnaire, with a cut-off point of 5/6. Other parameters related to individual perception of the explosion, health status, life events and habits were also assessed.
Having been in the vicinity of the explosion was the most significant factor (OR = 5.26, 95% CI 2.56–11.11) contributing to poorer mental health; erroneous knowledge of radiological hazard showed a mild association. In the sample group, anxiety after learning of the potential radiological hazard was significantly correlated with poor mental health (P<0.05), whereas anxiety about the explosion, or the degree of perception of it, was not; 74.5% of the sample group believed erroneously that the flash of the explosion was synonymous with radiation.
Having been in the vicinity of the atomic bomb explosion without radiological exposure continued to be associated with poorer mental health more than half a century after the event. Fear on learning about the potential radiological hazard and lack of knowledge about radiological risk are responsible for this association.
We focused on detailed evaluations of properties of the ultra-thin pore-seal layer (< 3 nm-thick), such as Cu diffusion barrier property and thermal stability. Cu diffusion into dense thermal silica and porous silica low-k which are covered with the pore seal layer was evaluated using metal-insulator-semiconductor (MIS) capacitors under bias thermal stress (BTS). Triangular voltage sweep (TVS) measurement shows that the ultra-thin layer on dense thermal silica suppresses the drift of Cu ions. The Time-Dependent Dielectric Breakdown (TDDB) lifetime of porous silica low-k covered with the ultra-thin pore seal layer results in a drastic increase of the capacitor lifetime with respect to the no-pore-seal control system (stable at 125 °C at least for 10000 s). Thermal decomposition of bulk material of the pore sealant was measured by thermal gravity (TG) test in nitrogen. Bulk material did not decompose through around 350 °C. The amount of ultra-thin pore seal layer fabricated on silicon wafer after thermal cycle stress in vacuum was measured by x-ray photoelectron spectroscopy (XPS). Amount of pore sealant did not decrease even after 2 cycles of 20 min, at 250 °C. Those results show that the ultra-thin layer, which we propose here, has a potential as a pore seal layer for porous low-k films.
Carbon nanotubes (CNTs) have been grown on silicon nanowires (SiNWs) by chemical vapor deposition using Co catalyst nanoparticles. Single-walled CNTs have been grown mainly when a thin Co film (0.1 nm thick) was deposited on SiNWs, while both SWNTs and MWNTs have been grown on SiNWs on which Co 0.5 nm thick was deposited. The correlation between the diameter of catalyst nanoparticles and that of CNTs has been investigated by transmission electron microscopy. The average diameter of CNTs is smaller than that of catalyst nanoparticles.
Analytical transmission electron microscopy (ATEM) was applied to investigate local variation of composition of transition metals in each particle of Fe-substituted Li2MnO3, which reveals high specific capacity and high voltage as a positive electrode. Crystal lattice images of primary particles were observed by means of high-resolution TEM (HRTEM), where local composition of Fe and Mn was determined by electron energy-loss spectroscopy (EELS). It was found that there exist both manganese (Mn)-rich and iron (Fe)-rich regions in a primary particle, where concentration of Fe and Mn fluctuates irregularly in nanometer scale. The relationship between composition and crystal structure in each local region is discussed.
A new organic precursor was designed and synthesized in order to form polymer films having low dielectric constants by a plasma-enhanced co-polymerization (PCP) technology. The organic monomer features a large aliphatic hydrocarbon structure, tricyclodecane (TCD) group. Optimized polymer films deposited from the monomer had dielectric constants less than 2.5. A solid 13C-NMR spectrum showed that the TCD moiety in the precursor was included in the polymer without changing the structure. The effect of the deposition temperature on the film structure was studied by analyzing Raman spectra. It was revealed that the dielectric constant is strongly associated with sp2 carbon content in the TCD-based polymer films.
A novel process of TMCTS vapor annealing combined with a plasma treatment has been developed for improving the mechanical strength of porous silica films having ultralow dielectric constant. When porous silica films annealed under 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) vapor were treated with argon plasma and then re-treated with TMCTS vapor, the mechanical strength (i.e., elastic modulus, hardness) of the films increased significantly. Results of Fourier transform infrared spectroscopy (FT-IR) suggested an accelerative effect resulted from the plasma treatment on the conversion of Si-CH3 and Si-H groups to Si-OH groups. The latter group appears to react faster with TMCTS from the second annealing to form cross-linked polymer network on the porous silica wall surfaces. The resulting cross-linked network is thought to keep the low permittivity and enhance the mechanical strength of the low-k films.
We report on magnetic properties of the GaN layers implanted with 3d transition metal ions. GaN layers grown by MOVPE on sapphire substrates, p- or n-doped, were implanted by Mn, Cr or V ions with a dose of 5×1016 cm−2 and implantation energy of 200 keV. Subsequently, a rapid thermal annealing in nitrogen atmosphere for 5 minutes at different temperatures (700°C – 1050°C) was performed. The magnetization as a function of magnetic field as well as the dependence on temperature revealed paramagnetic behavior for all samples. In addition, an antiferromagnetic coupling between implanted ions was found.
We have measured the growth rate of silicon nanowires (SiNWs) in the diameter range of 3 to 40 nm (8.4 nm on average), which were grown by chemical vapor deposition (CVD) at temperatures between 365 °C and 495 °C. It is found that SiNWs with smaller diameters grow slower than those with larger ones, and a critical diameter at which growth stops completely exists. The growth rate of the thinner SiNWs stronger depends on growth temperature than that of thicker ones in previous studies. We discuss the dependence by thermodynamics theory.
We use the self-interaction corrected (SIC) local spin-density (LSD) approximation to investigate the groundstate valency configuration of Mn impurities in p-type ZnO. In Zn1−xMnxO, we find the localized Mn2+ configuration to be preferred energetically. When codoping Zn1−xMnxO with N, we find that four d-states stay localized at the Mn site, while the remaining d-electron charge transfers into the hole states at the top of the valence bands. If the Mn concentration [Mn] is equal to the N concentration [N], this results in a scenario without carriers to mediate long range order. If on the other hand [N] is larger than [Mn], the N impurity band is not entirely filled, and carrier mediated ferromagnetism becomes theoretically possible.
We review our recent work on spin effects in low-dimensional electron gases studied using far-infrared photoconductivity technique. We measure the spin-orbit coupling parameter α via spectroscopy by detecting the combined resonance. Detailed filling-factor dependent study shows the collective nature of this excitation, in accordance to theoretical predictions that both Kohn and Larmor theorem are broken for long-wavelength excitations that changes both the Landau and spin quantum numbers. We find that the long spin-relaxation time of a two-dimensional electron gas results in a novel bolometric spin effect, which gives rise to a substantial photo resistance change by reversing the spin polarization of electrons at the Fermi-level.
Periodic 2-dimensional (2-D) hexagonal and the disordered pore structure
silica films have been developed using nonionic surfactants as the
templates. The pore structure was controlled by the static electrical
interaction between the micelle of the surfactant and the silica oligomer.
No X-ray diffraction peaks were observed for the disordered mesoporous
silica films, while the pore diameters of 2.0-4.0 nm could be measured by
small angle X-ray scattering spectroscopy. By comparing the properties of
the 2-D hexagonal and the disordered porous silica films which have the same
porosity, it is found that the disordered porous silica film has advantages
in terms of the dielectric constant and Young's modulus as well as the
hardness. The disordered porous silica film is more suitable for the
interlayer dielectrics for ULSI.
A novel organosiloxane-vapor-annealing method has been developed for
improving the mechanical strength of porous silica films with a low
dielectric constant. Treatment of a porous silica film with
1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) under atmospheric nitrogen
above 350 °C significantly enhanced the mechanical strength (i.e., elastic
modulus and hardness) of the film. Results of Fourier transform infrared
spectroscopy (FT-IR) and thermal desorption spectroscopy (TDS) suggested the
formation of cross-linked poly(TMCTS) network on the porous silica internal
wall surfaces by the TMCTS treatment. Such TMCTS cross-linked network is
thought to enhance the mechanical strength of the low-k film.