Scanning Deposition Method for Large-Area Diamond Film Synthesis Using Multiple Microwave Plasma Sources.

The demand for synthetic diamonds and research on their use in next-generation semiconductor devices have recently increased. Microwave plasma chemical vapor deposition (MPCVD) is considered one of the most promising techniques for the mass production of large-sized and high-quality single-, micro- and nanocrystalline diamond films. Although the low-pressure resonant cavity MPCVD method can synthesize high-quality diamonds, improvements are needed in terms of the resulting area. In this study, a large-area diamond synthesis method was developed by arranging several point plasma sources capable of processing a small area and scanning a wafer. A unit combination of three plasma sources afforded a diamond film thickness uniformity of ±6.25% at a wafer width of 70 mm with a power of 700 W for each plasma source. Even distribution of the diamond grains in a size range of 0.1-1 µm on the thin-film surface was verified using field-emission scanning electron microscopy. Therefore, the proposed novel diamond synthesis method can be theoretically expanded to achieve large-area films.

Anti-contamination SMART (Spectrum Monitoring Apparatus with Roll-to-roll Transparent film) window for optical diagnostics of plasma systems.

Optical emission spectroscopy is widely used in semiconductor and display manufacturing for plasma process monitoring. However, because of the contamination of the viewport, quantitative analysis is extremely difficult; therefore, qualitative analysis is used to detect species in the process. To extend plasma monitoring in advanced precise processes, the contamination problem of the viewport must be solved. We propose a new spectrum monitoring apparatus with a roll-to-roll transparent film window for optical diagnostics of a plasma system. By moving a transparent film in front of the viewport, contamination in the emission light path becomes negligible. However, the speed of the film should be optimized to reduce the maintenance period and to minimize measurement errors. We calculated the maximum thickness of SiO2, Si3N4, ITO, and the Ar/CHF3 plasma contaminant to suppress the electron temperature error measured by the line-intensity-ratio within 2% at 2 eV. The thickness of the Si3N4, ITO, and Ar/CHF3 plasma contaminant should be thinner than 12.5 nm, 7.5 nm, and 100 nm, respectively.

Diffusion-Weighted Imaging Findings of Ischemic Spinal Injury in a Chondrodystrophic Dog With Fibrocartilaginous Embolism.

A 9-year-old, intact male Shih Tzu dog presented with systemic weakness and peracute onset of tetraplegia. Tetraplegia with lower motor neuron signs was noted upon neurological examination. Diseases that cause acute flaccid tetraparesis, such as acute fulminating myasthenia gravis, polyradiculoneuritis, tick paralysis, and botulism, were ruled out based on the medical history, normal electrophysiological tests, and non-response to the neostigmine challenging test. Initial 0.3-Tesla (T) magnetic resonance imaging (MRI) findings included sharply demarcated intramedullary lesions at the C3-C6 level, mainly involving gray matter, which appeared hypo- to iso- intense on T1-weighted images (WIs), and hyperintense on T2-WIs and fluid-attenuated inversion recovery images. There was no enhancement on post-contrast T1-WIs. Neutrophilic pleocytosis was observed in the cerebrospinal fluid analysis. No clinical responses were observed for the treatment of non-infectious myelitis with an immunosuppressive dosage of prednisolone. A follow-up 3-T MRI 6 days later demonstrated hyperintensity on diffusion-WI (DWI) and a decreased apparent diffusion coefficient (ADC) value (0.54 × 10-3 mm2/s) of the spinal lesions. Through histological examination, a fibrocartilaginous embolism was definitively confirmed. This is the first report to describe an ischemic spinal injury visualized by DWI and ADC mapping with high-field MRI in a chondrodystrophic dog diagnosed with a fibrocartilaginous embolism.

Correlations of the frequency dependence of the ultrasonic backscatter coefficient with the bone volume fraction and the trabecular thickness in bovine trabecular bone: Application of the binary mixture model.

The ultrasonic backscatter coefficient and the exponent n (frequency dependence of the backscatter coefficient) were measured in 24 bovine femoral trabecular bone samples. The binary mixture model for ultrasonic scattering from trabecular bone was applied to predict the variations of the ultrasound parameters with the bone volume fraction (BV/TV) and the trabecular thickness (Tb.Th) in trabecular bone. The backscatter coefficient exhibited significant, positive correlations with the BV/TV (R = 0.82) and the Tb.Th (R = 0.79). In contrast, the exponent n was found to be significantly, negatively correlated with the BV/TV (R = -0.77) and the Tb.Th, (R = -0.71).

Thickness dependences of acoustic bandgaps with different generation mechanisms in phononic crystals immersed in water.

The thickness dependences of acoustic bandgaps were theoretically and experimentally investigated in two-dimensional phononic crystals (PCs) immersed in water. The acoustic pressure transmission coefficients were measured as a function of the PC thickness in order to understand the characteristics of the transmission loss through the PCs. The acoustic bandgaps can be classified into two types of generation mechanisms from the perspective of acoustic diffraction modes: Bragg bandgap and non-zeroth order diffraction (NZOD) bandgap. The NZOD bandgaps show larger transmission losses and shorter decay lengths with increasing PC thickness than the Bragg bandgaps.

Velocity dispersion and backscatter in marrow-filled and water-filled trabecular bone samples in vitro.

The phase velocity and the backscatter coefficient were measured in 28 bovine femoral trabecular bone samples filled with marrow and water in vitro from 0.2 to 0.6 MHz. The phase velocities decreased approximately linearly with increasing frequency and the average dispersion rate of -34 ms-1 MHz-1 in the marrow-filled samples was higher than that of -42 ms-1 MHz-1 in the water-filled samples. The backscatter coefficients exhibited nonlinear, monotonically increasing dependences on the frequency and the average value of the exponent n = 2.92 (frequency dependence) in the marrow-filled samples was higher than the value of n = 2.79 in the water-filled samples.

Zeroth-order resonance phenomenon in an acoustic composite right/left-handed metamaterial resonator.

This study proposes an acoustic theory that describes the resonance phenomena in a resonator made of acoustic composite right/left-handed (CRLH) metamaterials, and verifies it through numerical simulation. The established theory for a microwave CRLH metamaterial resonator is adapted to explain the resonance phenomena in an acoustic CRLH metamaterial resonator. In particular, attention is focused on the zeroth-order resonance phenomenon which has several interesting properties. When a resonator is composed of a CRLH metamaterial, a resonance with a flat acoustic field distribution may occur at one of the frequencies where the wavenumber becomes zero. This resonance is called zeroth-order resonance. Through numerical simulation, such unusual resonance phenomenon in acoustics is observed in more detail and the proposed theory is verified. The results of the theory and the numerical simulation clearly show that zeroth-order resonance can exist at those frequencies where the acoustic field distribution is flat due to infinite wavelength. It is also shown that the resonance frequency and the Q factor of this resonance depend on the boundary condition at both ends of the resonator, and they basically do not change even when the number of units is reduced or increased.

Are there differences in brain morphology according to handedness?

OBJECTIVE: This study aimed to investigate the differences in brain morphology according to handedness. MATERIALS AND METHODS: Forty-two healthy subjects were enrolled (21 right-handers and 21 nonright-handers). The two groups were classified according to the Edinburgh Handedness Inventory. Measures of cortical morphology, such as thickness, surface area, volume, and curvature, and the volumes of subcortical structures, such as the amygdala, caudate, hippocampus, globus pallidus, putamen, and thalamus, were compared between the groups according to handedness using whole-brain 3D T1-weighted MRI. In addition, we investigated the white matter differences between the groups using diffusion tensor imaging. Moreover, we quantified correlations between the handedness scales of the Edinburgh Handedness Inventory and each measure of different brain morphologies. RESULTS: The volumes of the right putamen and left globus pallidus in nonright-handed participants were significantly larger than those who were right-handed (0.3559 vs. 0.3155%, p = .0028; 0.1101 vs. 0.0975%, p = .0025; respectively). Moreover, the volumes of the right putamen and left globus pallidus were negatively correlated with the handedness scales of the Edinburgh Handedness Inventory (r = -.392, p = .0101; r = -.361, p = .0189; respectively). However, the cortex morphology and the other subcortical volumes were not significantly different between the two groups. In addition, we did not find any white matter differences between the groups. CONCLUSIONS: We demonstrated that there were significant differences in brain morphology between right-handers and nonright-handers, especially in the basal ganglia, which could produce differences in motor control according to handedness.

Relationships of the group velocity of the time-reversed Lamb wave with bone properties in cortical bone in vitro.

The present study aims to investigate the feasibility of using the time-reversed Lamb wave as a new method for noninvasive characterization of long cortical bones. The group velocity of the time-reversed Lamb wave launched by using the modified time reversal method was measured in 15 bovine tibiae, and their correlations with the bone properties of the tibia were examined. The group velocity of the time-reversed Lamb wave showed significant positive correlations with the bone properties (r=0.55-0.81). The best univariate predictor of the group velocity of the time-reversed Lamb wave was the cortical thickness, yielding an adjusted squared correlation coefficient (r2) of 0.64. These results imply that the group velocity of the time-reversed Lamb wave, in addition to the velocities of the first arriving signal and the slow guided wave, could potentially be used as a discriminator for osteoporosis.

Conessine Interferes with Oxidative Stress-Induced C2C12 Myoblast Cell Death through Inhibition of Autophagic Flux.

Conessine, a steroidal alkaloid isolated from Holarrhena floribunda, has anti-malarial activity and interacts with the histamine H3 receptor. However, the cellular effects of conessine are poorly understood. Accordingly, we evaluated the involvement of conessine in the regulation of autophagy. We searched natural compounds that modulate autophagy, and conessine was identified as an inhibitor of autophagic flux. Conessine treatment induced the formation of autophagosomes, and p62, an autophagic adapter, accumulated in the autophagosomes. Reactive oxygen species such as hydrogen peroxide (H2O2) result in muscle cell death by inducing excessive autophagic flux. Treatment with conessine inhibited H2O2-induced autophagic flux in C2C12 myoblast cells and also interfered with cell death. Our results indicate that conessine has the potential effect to inhibit muscle cell death by interfering with autophagic flux.

Relationships of linear and nonlinear ultrasound parameters with porosity and trabecular spacing in trabecular-bone-mimicking phantoms.

The speed of sound (SOS), the normalized broadband ultrasound attenuation (nBUA), and the nonlinear parameter (B/A) were measured in 18 trabecular-bone-mimicking phantoms consisting of water-saturated aluminum foams. The strong slow wave and the very weak fast wave were consistently observed in the signals transmitted through all of the phantoms. It was found that the SOS increased as the porosity and the trabecular spacing increased. In contrast, both the nBUA and the B/A showed opposite dependences on the porosity and the trabecular spacing. All three ultrasound parameters exhibited high correlation coefficients with the porosity and the trabecular spacing.

Development of plasma assisted thermal vapor deposition technique for high-quality thin film.

The novel technique of Plasma-Assisted Vapor Deposition (PAVD) is developed as a new deposition method for thin metal films. The PAVD technique yields a high-quality thin film without any heating of the substrate because evaporated particles acquire energy from plasma that is confined to the inside of the evaporation source. Experiments of silver thin film deposition have been carried out in conditions of pressure lower than 10-3 Pa. Pure silver plasma generation is verified by the measurement of the Ag-I peak using optical emission spectroscopy. A four point probe and a UV-VIS spectrophotometer are used to measure the electrical and optical properties of the silver film that is deposited by PAVD. For an ultra-thin silver film with a thickness of 6.5 nm, we obtain the result of high-performance silver film properties, including a sheet resistance <20 Ω sq-1 and a visible-range transmittance >75%. The PAVD-film properties show a low sheet resistance of 30% and the same transmittance with conventional thermal evaporation film. In the PAVD source, highly energetic particles and UV from plasma do not reach the substrate because the plasma is completely shielded by the optimized nozzle of the crucible. This new PAVD technique could be a realistic solution to improve the qualities of transparent electrodes for organic light emission device fabrication without causing damage to the organic layers.

The integral membrane protein ITM2A, a transcriptional target of PKA-CREB, regulates autophagic flux via interaction with the vacuolar ATPase.

The PKA-CREB signaling pathway is involved in many cellular processes including autophagy. Recent studies demonstrated that PKA-CREB inhibits autophagy in yeast; however, the role of PKA-CREB signaling in mammalian cell autophagy has not been fully characterized. Here, we report that the integral membrane protein ITM2A expression is positively regulated by PKA-CREB signaling and ITM2A expression interferes with autophagic flux by interacting with vacuolar ATPase (v-ATPase). The ITM2A promoter contains a CRE element, and mutation at the CRE consensus site decreases the promoter activity. Forskolin treatment and PKA expression activate the ITM2A promoter confirming that ITM2A expression is dependent on the PKA-CREB pathway. ITM2A expression results in the accumulation of autophagosomes and interferes with autolysosome formation by blocking autophagic flux. We demonstrated that ITM2A physically interacts with v-ATPase and inhibits lysosomal function. These results support the notion that PKA-CREB signaling pathway regulates ITM2A expression, which negatively regulates autophagic flux by interfering with the function of v-ATPase.

The anti-hypertensive drug reserpine induces neuronal cell death through inhibition of autophagic flux.

Reserpine is a well-known medicine for the treatment of hypertension and schizophrenia, but its administration can induce Parkinson's disease (PD)-like symptoms in humans and animals. Reserpine inhibits the vesicular transporter of monoamines and depletes the brain of monoamines such as dopamine. However, the cellular function of reserpine is not fully understood. In this report, we present one possible mechanism by which reserpine may contribute to PD-like symptoms. Reserpine treatment induced the formation of enlarged autophagosomes by inhibiting the autophagic flux and led to accumulation of p62, an autophagy adapter molecule. In particular, reserpine treatment increased the level of α-synuclein protein and led to accumulation of α-synuclein in autophagosomes. Treatment with rapamycin enhanced the effect of reserpine by further increasing the level of α-synuclein and neuronal cell death. Drosophila raised on media containing reserpine showed loss of dopaminergic neurons. Furthermore, cotreatment with reserpine and rapamycin aggravated the loss of dopaminergic neurons. Our results suggest that reserpine contributes to the loss of dopaminergic neurons by interfering with autophagic flux.

Dependences of ultrasonic properties on frequency and trabecular spacing in trabecular-bone-mimicking phantoms.

The dependences of ultrasonic properties on the frequency and the trabecular spacing were investigated in 20 trabecular-bone-mimicking phantoms consisting of cellular copper foams. The strong slow waves were consistently observed in the signals transmitted through all of the phantoms. The frequency-dependent phase velocity and attenuation coefficient of the slow wave were measured at frequencies from 0.7 to 1.3 MHz. The phase velocity decreased approximately linearly with increasing frequency while the attenuation coefficients increased with increasing frequency. The phase velocity increased monotonically with increasing trabecular spacing from 1337 to 2931 µm while the attenuation coefficient decreased with increasing spacing.

Propagation of time-reversed Lamb waves in bovine cortical bone in vitro.

The present study aims to investigate the propagation of time-reversed Lamb waves in bovine cortical bone in vitro. The time-reversed Lamb waves were successfully launched at 200 kHz in 18 bovine tibiae through a time reversal process of Lamb waves. The group velocities of the time-reversed Lamb waves in the bovine tibiae were measured using the axial transmission technique. They showed a significant correlation with the cortical thickness and tended to follow the theoretical group velocity of the lowest order antisymmetrical Lamb wave fairly well, consistent with the behavior of the slow guided wave in long cortical bones.

Measurement of antibodies to varicella-zoster virus using a virus-free fluorescent-antibody-to-membrane-antigen (FAMA) test.

The fluorescent-antibody-to-membrane-antigen (FAMA) test is regarded as the "gold standard" to detect protective antibodies to varicella-zoster virus (VZV) because of its high sensitivity and specificity. Because the classic FAMA test uses an infectious virus for detection of antibodies to VZV, it is labor-intensive, and also requires special equipment for handling the virus. For this reason, we attempted to develop a simple and safe FAMA assay. Because VZV glycoprotein E (gE) is one of the major VZV glycoproteins, we used the gE protein for the FAMA test (gE FAMA). Here, we demonstrate that overexpression of gE in HEK293T cells can be used to measure antibodies in human serum, and that gE FAMA titers are closely correlated with gpEIA ELISA data. These results indicate that our gE FAMA test has the potential to measure antibodies to VZV.

Dependences of quantitative ultrasound parameters on frequency and porosity in water-saturated nickel foams.

The frequency-dependent phase velocity, attenuation coefficient, and backscatter coefficient were measured from 0.8 to 1.2 MHz in 24 water-saturated nickel foams as trabecular-bone-mimicking phantoms. The power law fits to the measurements showed that the phase velocity, the attenuation coefficient, and the backscatter coefficient were proportional to the frequency with exponents n of 0.95, 1.29, and 3.18, respectively. A significant linear correlation was found between the phase velocity at 1.0 MHz and the porosity. In contrast, the best regressions for the normalized broadband ultrasound attenuation and the backscatter coefficient at 1.0 MHz were obtained with the polynomial fits of second order.

Correlations of linear and nonlinear ultrasound parameters with density and microarchitectural parameters in trabecular bone.

In the present study, correlations of linear and nonlinear ultrasound parameters (speed of sound, normalized broadband ultrasound attenuation, and nonlinear parameter B/A) with bone mineral density and microarchitectural parameters were investigated in 28 bovine femoral trabecular bone samples in vitro. All three ultrasound parameters exhibited relatively high correlation coefficients with the indexes of bone quantity (bone mineral density and bone volume fraction) and lower correlation coefficients with the remaining microarchitectural parameters. These results suggest that B/A, in addition to speed of sound and attenuation, may have potential as an index for the assessment of bone status and osteoporosis.

Temperature-dependent thermal properties of ex vivo liver undergoing thermal ablation.

Thermotherapy uses a heat source that raises temperatures in the target tissue, and the temperature rise depends on the thermal properties of the tissue. Little is known about the temperature-dependent thermal properties of tissue, which prevents us from accurately predicting the temperature distribution of the target tissue undergoing thermotherapy. The present study reports the key thermal parameters (specific heat capacity, thermal conductivity and heat diffusivity) measured in ex vivo porcine liver while being heated from 20 ° C to 90 ° C and then naturally cooled down to 20 ° C. The study indicates that as the tissue was heated, all the thermal parameters resulted in plots with asymmetric quasi-parabolic curves with temperature, being convex downward with their minima at the turning temperature of 35-40 ° C. The largest change was observed for thermal conductivity, which decreased by 9.6% from its initial value (at 20 ° C) at the turning temperature (35 ° C) and rose by 45% at 90 ° C from its minimum (at 35 ° C). The minima were 3.567 mJ/(m(3) ∙ K) for specific heat capacity, 0.520 W/(m.K) for thermal conductivity and 0.141 mm(2)/s for thermal diffusivity. The minimum at the turning temperature was unique, and it is suggested that it be taken as a characteristic value of the thermal parameter of the tissue. On the other hand, the thermal parameters were insensitive to temperature and remained almost unchanged when the tissue cooled down, indicating that their variations with temperature were irreversible. The rate of the irreversible rise at 35 ° C was 18% in specific heat capacity, 40% in thermal conductivity and 38.3% in thermal diffusivity. The study indicates that the key thermal parameters of ex vivo porcine liver vary largely with temperature when heated, as described by asymmetric quasi-parabolic curves of the thermal parameters with temperature, and therefore, substantial influence on the temperature distribution of the tissue undergoing thermotherapy is expected.