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The failure process caused by overvoltage stress in cascode GaN–field effect transistors (FETs) is discussed through single unclamped inductive switching (UIS) waveforms, burst UIS waveforms, and capacitance–voltage characteristic shifts. One of the critical disadvantages of GaN–high electron mobility transistors (HEMTs) is their lack of UIS withstand capability, primarily because there is no mechanism for removing holes generated by avalanche breakdown. The device failure is observed at the drain voltage peak in the single UIS, and sudden and random breaks are observed in the burst UIS even with the same overvoltage stress. Both hole and electron traps after the burst UIS are observed, and the failure position is at the chip edge. From these results, it is verified that cascode GaN–FETs are broken due to time‐dependent dielectric breakdown of passivation films. [ABSTRACT FROM AUTHOR]

Background: Recently, Oblique lumbar interbody fusion (OLIF) is commonly indicated to correct the sagittal and coronal alignment in adult spinal deformity (ASD). Endplate fracture during surgery is a major complication of OLIF, but the detailed location of fracture in vertebral endplate in ASD has not yet been determined. We sought to determine the incidence and location of endplate fracture and subsidence of the OLIF cage in ASD surgery, and its association with fusion status and alignment.Methods: We analyzed 75 levels in 27 patients were analyzed using multiplanar CT to detect the endplate fracture immediately after surgery and subsidence at 1 year postoperatively. The prevalence was compared between anterior and posterior, approach and non-approach sides, and concave and convex side. Their association with fusion status, local and global alignment, and complication was also investigated.Results: Endplate fracture was observed in 64 levels (85.3%) in all 27 patients, and the incidence was significantly higher in the posterior area compared with the anterior area (85.3 vs. 68.0%, p=0.02) of affected vertebra in the sagittal plane. In the coronal plane, there was no significant difference in incidence between left (approach) and right (non-approach) sides (77.3 and 81.3%, respectively), or concave and convex sides (69.4 and 79.6%) of wedged vertebra. By contrast, cage subsidence at 1 year postoperatively was noted in 14/75 levels (18.7%), but was not associated with endplate fracture. Fusion status, local and global alignment, and complications were not associated with endplate fracture or subsidence.Conclusion: Endplate fracture during OLIF procedure in ASD cases is barely avoidable, possibly induced by the corrective maneuver with ideal rod counter and cantilever force, but is less associated with subsequent cage subsidence, fusion status, and sustainment of corrected alignment in long fusion surgery performed even for elderly patients. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical characteristics of patients with acute zonal occult outer retinopathy (AZOOR), according to the presence or absence of anti-retinal antibodies (ARAs) that are frequently detected in autoimmune retinopathy. Methods: Retrospective observational case series. This study included 33 patients with acute-stage AZOOR who had been followed up for more than 6 months after the initial visit. The median follow-up period was 26 months. Immunoblot analyses were used to detect autoantibodies for recoverin, carbonic anhydrase II, and α-enolase in serum from these patients. Main outcome measures comprised clinical factors at the initial and final visits, including best-corrected visual acuity, mean deviation on Humphrey perimetry, and retinal morphology, which were statistically compared between patients with AZOOR who exhibited ARAs and those who did not. Results: At least one serum ARA was detected in 42% of patients with AZOOR. There were no significant differences in clinical factors between the two groups, including follow-up period, best-corrected visual acuity and mean deviation at the initial and final visits, a-wave amplitude on single-flash electroretinography at the initial visit, and frequencies of improvement of the macular ellipsoid zone and AZOOR recurrence. Conclusions: Our findings suggest that the presence of ARAs did not influence visual outcomes or outer retinal morphology in patients with AZOOR. [ABSTRACT FROM AUTHOR]

Background: The perioperative complication rate for spinal fusion in Duchenne muscular dystrophy (DMD) remains high and sometimes prolonged perioperative intensive care is needed. We investigated preoperative and intraoperative risk factors associated with prolonged intensive care unit (ICU) stay after posterior spinal fusion.Methods: We reviewed the records of 49 consecutive DMD patients who underwent posterior spinal fusion. Instrumentation was performed from T4 to L5 (46 cases) or to the ilium (3 cases). We recorded the preoperative Cobb angle and perioperative clinical data from patient records. Patients were divided into two groups (ICU stay 0 or 1 day, 2 days or longer). Chi-square and t tests were used for univariate analysis. Factors with p < 0.05 in the univariate analysis were entered into a multilevel logistic regression analysis.Results: The average age of patients at surgery was 14.2 years (range 11-20 years). Their preoperative Cobb angle was 79.2° (range 40°-154°). Average operative time was 325.3 min (range 225-507 min). The average estimated blood loss (EBL) was 1673.0 ml (range 500-3785 ml). Eight patients stayed in the ICU for 2 days or longer for postoperative monitoring and treatment. Univariate analysis found statistical difference between the two groups in preoperative Cobb angle, Thoracolumbar kyphosis, %VC, operation time, and EBL during surgery. After multiple logistic regression analysis, Cobb angle and EBL was identified as an independent factor. The patients with a larger Cobb angle and greater EBL had a higher rate of prolonged ICU stay in interquartile range-based comparison.Conclusions: The present study suggests the preoperative Cobb angle and intraoperative EBL could be predictors for postoperative course in posterior spinal fusion for DMD patients. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to demonstrate the clinical course of Japanese patients with macular telangiectasia type 2 (MacTel-2). Methods: This retrospective observational case series included 16 eyes of 8 Japanese patients (3 men and 5 women) with MacTel-2. The mean age and follow-up duration was 66.9 years and 42.8 months, respectively. Differences in best-corrected visual acuity (BCVA), funduscopic macular findings, central macular thickness (CMT), and the length of macular ellipsoid zone (EZ) loss were compared between the initial/baseline and final visits. Optical coherence tomographic changes in CMT by ≥ 20% and in EZ loss by ≥ 20% or ≥ 100 μm were defined as improved or worsened. Results: Numerical changes in BCVA and EZ loss during follow-up were not statistically significant. However, the mean CMT at baseline, which was lower than that of healthy control eyes (P < 0.001), significantly increased during follow-up (P = 0.041). A certain proportion of eyes showed improvement in several parameters: funduscopic findings (both parafoveal retinal graying and foveal retinal pigment epithelium depigmentation) in 29% of eyes, CMT in 21% of eyes, and EZ loss in 43% of eyes. Conclusions: The non-negligible proportion of eyes with improved parameters, marked especially by macular EZ loss, suggests that Japanese patients with MacTel-2 have milder clinical features than Caucasian patients reported in the literature. [ABSTRACT FROM AUTHOR]

A new gate structure in the trench-gate insulated-gate bipolar transistor (IGBT) design is proposed and analyzed for power-loss reduction and the suppression of electromagnetic-interference (EMI) noise. Although the turn-off loss and the ON-state voltage drop Vce(sat) are improved by the injection-enhancement (IE) effect, the IE effect caused dynamic avalanche that limits the turn-off loss reduction. In addition, EMI noise is induced by high dI/dt and large surge current due to the negative gate capacitance. This article shows that the dynamic avalanche and the negative gate capacitance can be suppressed by the management of the electric field concentration and hole current flow around the trench gate by the proposed alternated trench-gate (AT) IGBT structure, and both low power loss and good switching controllability can be obtained. The device simulation results show that the AT-IGBT improves the turn-on surge current Isurge-Vce(sat) tradeoff compared with the conventional IGBTs. [ABSTRACT FROM AUTHOR]

A new structure in trench-gate insulated gate bipolar transistor (IGBT) design is proposed and analyzed not only for power loss reduction but also for long-term stability and suppressing electromagnetic interference (EMI) noise using a device simulation. Although turn-off loss and ON-state voltage drop Vce(sat) are improved by injection enhancement (IE) effect, IE effect causes dynamic avalanche that limits turn-off loss reduction and degrades long-term stability by the charge trap at the trench gate oxide interface. In addition, hole current around the gate induces EMI noise due to the negative gate capacitance. This article shows that the proposed surface buffer (SB) IGBT suppresses dynamic avalanche and negative gate capacitance maintaining low power loss by covering the trench gate bottom and hole evacuation from the pMOS channel. [ABSTRACT FROM AUTHOR]

Validation and verification of cleaning and inspection methods are essential to prevent the spread of allergens via cross-contact. Among the hygiene monitoring tests used on-site, the ATP test is rapid and provides quantifiable results. Nevertheless, because a wide variety of foods contain significant amount of ADP and/or AMP due to the degradation of ATP, the ATP+ADP+AMP (A3) test is preferred for detecting food debris. Hence, the A3 test may be valuable in screening food debris that may contain residual allergens. In this study, the detection limits of the A3 test for 40 foods that are regulated in several countries as allergenic were compared with those of the other hygiene monitoring tests used on-site: the conventional ATP test with similar sensitivity for ATP, the protein swab test that detects as little as 50 μg of protein, and the lateral flow immunoassay (LFI). The A3 test demonstrated lower detection limits than did the ATP test. The detection sensitivity of the A3 test was greater than that of the protein swab test except for its use on gelatin (extracted protein). The cleaning validation performance using a stainless steel model in fish and meat revealed that the A3 test is efficient in verifying the levels of remaining food debris. Although LFI displayed the best sensitivities for 10 of 14 foods, it is not commercially available for some specific allergens; however, the A3 test can detect such food debris. Moreover, the detection limits of the A3 test were preferable or comparable to those of LFI for crustacean shellfish and for processed grains, with the exception of wheat flour and buckwheat. A field study in a food processing plant demonstrated that the amount of both A3 and milk protein (enzyme-linked immunosorbent assay) considerably decreased as the cleaning steps progressed. Therefore, the A3 test is effective in detecting the risk for allergen cross-contact after inadequate cleaning. ADP and/or AMP predominate over ATP in many allergenic foods. LFI showed better sensitivity than other nonspecific methods. The A3 test can detect foods for which LFI is not commercially available. The A3 test is effective in detecting the risk for allergen contamination. [ABSTRACT FROM AUTHOR]

Mg2Si is a potential thermoelectric (TE) material that can directly convert waste energy into electricity. In expectation of improving its TE performance by increasing electron carrier concentration, the element boron (B) is doped in Mg2Si single crystals (SCs). Their detailed crystal structures are definitely determined by using white neutron holography and single-crystal x-ray diffraction (SC-XRD) measurements. The white neutron holography measurement proves that the doped B atom successfully substitutes for the Mg site. The SC-XRD measurement confirms the B-doping site and also reveals the presence of the defect of Si vacancy (VSi) in the B-doped Mg2Si SCs. The fraction of VSi increases with increasing B-doping concentration. In the case of B-doped Mg2Si polycrystals (PCs), VSi is absent; this difference between the SCs and PCs can be attributed to different preparation temperatures. Regarding TE properties, the electrical conductivity, σ, and the Seebeck coefficient, S, decreases and increases, respectively, due to the decrease in the electron carrier concentration, contrary to the expectation. The power factor of the B-doped Mg2Si SCs evaluated from σ and S does not increase but rather decreases by the B-doping. The tendencies of these TE properties can be explained by considering that the donor effect of the B atom is canceled by the acceptor effect of VSi for the B-doped Mg2Si SCs. This study demonstrates that the preparation condition of Mg2Si should be optimized to prevent the emergence of an unexpected point defect. [ABSTRACT FROM AUTHOR]

Purpose: To compare the clinical characteristics of Vogt-Koyanagi-Harada (VKH) disease patients with and without anti-retinal antibodies (ARAs) that are frequently detected in autoimmune retinopathy. Methods: Using immunoblot analyses, serum autoantibodies for recoverin, carbonic anhydrase II, and α-enolase were examined in 20 treatment-naïve patients with VKH disease. Clinical factors before and after systemic corticosteroid therapy, including best-corrected visual acuity (BCVA) and macular outer retinal morphology, were statistically compared between patients with VKH disease with and without ARAs. Results: Serum ARAs were detected in 50.0% of patients with VKH disease. There were no significant differences in clinical factors between the two groups, including final BCVA, frequency of uveitis recurrence, and recovery of the macular ellipsoid zone after systemic corticosteroid therapy. Conclusions: Our results suggest that the detected ARAs did not influence visual outcomes, the chronicity of uveitis, or outer retinal morphology in patients with VKH disease. [ABSTRACT FROM AUTHOR]

Purpose. To investigate relationships between total thickness and the thickness of inner and outer layers in the choroid during regression in patients with multiple evanescent white dot syndrome (MEWDS). Methods. This retrospective observational case series included 15 unilaterally affected eyes and 13 unaffected fellow eyes from 15 MEWDS patients (4 men and 11 women; mean age, 37.6 ± 17.6 years). Using enhanced depth imaging optical coherence tomography, whole, inner, and outer choroidal layer thicknesses at the fovea and perifovea were manually measured at the initial visit and at 1 and 3 months after the initial visit. The mean thickness values of the layers were compared at each stage. Results. With regression of MEWDS, the mean subfoveal whole and inner choroidal layer thicknesses significantly decreased at 1 and 3 months compared to baseline values in MEWDS eyes (P=0.01 and P<0.0001, respectively), but not in fellow eyes. The outer layer in MEWDS eyes tended to thin. Changes in the inner and outer layers at the perifovea in MEWDS eyes also showed the same trends. Simple linear regression analysis revealed significant positive correlations in choroidal thickness changes between the whole and inner layers (R = 0.53, P=0.04) and between the whole and outer layers (R = 0.91, P<0.0001) from baseline to 3 months. Multiple linear regression analysis revealed that choroidal thickness changes in the whole layer were significantly correlated with those in the inner (β = 0.51, P<0.0001) and outer (β = 0.73, P<0.0001) layers. Conclusion. The inner choroidal layer significantly thinned with regression of MEWDS, correlating with the thinning of total choroidal thickness. These results suggest that MEWDS lesions in the choroid are likely to lie mainly in the inner layer. [ABSTRACT FROM AUTHOR]

The aim of the present study was to form a nitride layer on a titanium (Ti) substrate through a compact laser‐nitriding system comprising a focused pulsed Nd:YAG laser and nitrogen gas blow. To obtain a high‐quality layer, the effects of pulse frequency and gas flow rate on the surface characteristics were investigated by using plasma emission analysis as well as X‐ray analyses. Optical emission spectra from the laser‐induced plasma mainly consisted of ionic Ti lines, and their intensities when the pulse frequency was 15 Hz were much higher than those for 8 Hz. Similarly, the reflections from the δ‐TiN phase in the X‐ray diffraction (XRD) pattern were enhanced when using 15 Hz. On the other hand, the flow rate of nitrogen gas blow had a significant effect on the thickness of the thin oxide layer that formed above the nitride layer. Using a lower flow rate resulted in the formation of a thicker oxide layer. The higher pulse frequency and the faster flow rate were beneficial for obtaining a higher‐quality layer because of the enhancement of nitridation and the suppression of oxidation, respectively. [ABSTRACT FROM AUTHOR]

Abstract The lipoxygenase-1-null (LOX-less) trait has positive effects on beer quality, and in particular, improvement of flavor stability by reduction of beer deteriorating substances such as trans -2-nonenal (T2N). 'SouthernStar' was successfully developed as the first LOX-less malting barley variety in Australia by introducing LOX-less trait into 'Flagship' by successive backcross and molecular marker assisted selection (MMAS). 'Flagship' is a two-rowed malting barley variety in Australia and it was used as the recurrent parent for the successive backcrossing. The yield potential, agronomic performance, disease resistance and the general malting quality were almost identical between 'SouthernStar' and 'Flagship'. To evaluate effects of LOX-less trait on beer quality, the brewing trials were conducted using a pilot-scale brewing apparatus. The wort and beer quality were similar between 'SouthernStar' and 'Flagship'. The effect of the LOX-less trait on the reduction of beer deteriorating substances such as T2N and trihydroxyoctadecenoic acid (THOD) contents was clearly verified in this study. The scores for total staleness of the test beers were significantly lower than those of the control beers under several storage conditions in one trial. Highlights • A new lipoxygenase-1-less (LOX-less) malting barley variety 'SouthernStar' developed by backcrossing. • Similar agricultural characteristics and malting quality as a recurrent parent 'Flagship'. • Reduction of trihydroxyoctadecenoic acid (THOD) and trans -2-nonenal (T2N) contents in beer by LOX-less trait introduced. • Improvement of flavor stability evaluated by sensory analysis for stale beer. [ABSTRACT FROM AUTHOR]

Purpose. To evaluate the surgical outcomes of pars plana vitrectomy (PPV) with epipapillary membrane removal in patients with maculopathy associated with cavitary optic disc anomalies. Methods. Eight patients (8 eyes) with cavitary optic disc anomaly-associated maculopathy who underwent PPV with epipapillary membrane removal were retrospectively reviewed. The best-corrected visual acuity (BCVA) and macular and papillary morphologies using enhanced depth imaging optical coherence tomography (EDI-OCT) were evaluated before and after treatment. Immunohistochemistry for an intraoperatively excised epipapillary membrane tissue was also performed. Results. Before surgery, EDI-OCT revealed that epipapillary membrane was observed in all patients. Retinoschisis was resolved with no recurrence in all patients following vitrectomy regardless of a disease type or the presence or absence of preoperative posterior vitreous detachment. The mean final BCVA and central retinal thickness significantly improved compared with pretreatment values (P=0.008 and 0.004, resp.). Immunoreactivity for S100 protein and glial fibrillary acidic protein, markers of astrocytes, was positive in the resected membrane tissues. Conclusions. These results suggest that epipapillary membrane is involved in the pathogenesis of some patients with cavitary optic disc anomaly-associated maculopathy as well as posterior hyaloid membrane. PPV with epipapillary membrane removal may be a useful treatment option for this maculopathy. This trial is registered with UMIN000011123. [ABSTRACT FROM AUTHOR]

Purpose. To evaluate sequential changes in choroidal thickness at the affected area in patients with acute zonal occult outer retinopathy (AZOOR). Methods. This retrospective observational case series included 14 affected eyes and 6 unaffected fellow eyes from 10 AZOOR patients with impaired macular area. Using enhanced depth imaging optical coherence tomography, choroidal thicknesses at the subfovea and at nasal and temporal sites 1000 μm away from the fovea were manually measured at baseline and 3 and 6 months thereafter. Changes in the choroidal thicknesses and the average threshold at the affected area on Humphrey perimetry were compared during the 6-month follow-up. Results. In AZOOR eyes, the average threshold at the affected area significantly increased over time, while outer retinal structure ameliorated. The mean choroidal thicknesses at all the sites measured significantly decreased at 3 and 6 months compared with baseline values in AZOOR eyes, but not in fellow eyes. There was an inverse correlation between the changing rates of the average threshold and the subfoveal choroidal thickness at 6 months from baseline. Conclusion. The current data suggest that choroidal thickness at AZOOR-affected area significantly decreased with regression of AZOOR and this anatomical change correlated with the functional recovery. [ABSTRACT FROM AUTHOR]

Background: Fukuyama congenital muscular dystrophy (FCMD) is one of the most common congenital progressive muscular dystrophies in Japan. Some patients develop a severe spinal deformity that leads to an unstable sitting position or pain. Since 2008, we have treated FCMD using posterior spinal fusion. This study reports the short-term clinical and radiographic results of posterior spinal correction and fusion in FCMD.Methods: We retrospectively reviewed 11 consecutive FCMD patients, average age 13 years old, treated with posterior spinal instrumentation and fusion between 2008 and 2015. All patients were non-ambulatory and complained about difficulty sitting and/or buttock pain. Posterior spinal correction was performed to halt progression of spinal deformity and improve their sitting balance. Assessment was performed clinically and with radiological measurements at a mean follow up period of 34.5 months. To evaluate functional status of patients after surgery objectively, a Muscular Dystrophy Spine Questionnaire (MDSQ) was obtained at the final follow up.Results: The mean height, weight and body mass index of the patients were 144.1 ± 11.8 cm, 26.5 ± 8.7 kg and 12.5 ± 2.6 kg/m2. The average intensive care unit stay was 1.3 days. Five patients had complications related to surgery. The mean preoperative major Cobb angle and pelvic obliquity (PO) were 65.5 ± 41.7° and 31.4 ± 28.9°, respectively, were corrected to 34.4 ± 29.7° and 20.0 ± 18.7° just after the surgery, and were maintained at 35.1 ± 29.9° and 20.5 ± 21.1° at the final follow up. The average MDSQ score was 35.8 ± 13.2 at the final follow up.Conclusion: Posterior spinal correction and fusion in FCMD achieved good radiographic results and clinical improvement with acceptable perioperative complications. FCMD patients are mentally impaired and physically small, so post-operative observation and close attention to perioperative complications are critical. [ABSTRACT FROM AUTHOR]

Purpose: To determine if early post-treatment central choroidal thickness (CCT) changes can predict sunset glow fundus (SGF) development in patients with Vogt-Koyanagi-Harada (VKH) disease treated using systemic corticosteroids. Methods: This retrospective case series included 39 eyes of 21 treatment-naïve patients with acute VKH disease who could be followed up for more than 12 months after systemic corticosteroid therapy. The eyes were divided into two groups according to whether SGF was present or absent at 12 months (9 eyes of 5 patients versus 30 eyes of 16 patients, respectively). Using enhanced depth imaging optical coherence tomography, CCT values were measured before treatment, then at 1 week and 1 and 3 months after treatment in both groups and compared between the two groups. Results: Development of SGF was found 4–11 months after treatment. Mean post-treatment CCT decreased significantly at all examinations compared with baseline in both groups, along with resolution of serous retinal detachment. One week after treatment, mean CCT was significantly higher in eyes with SGF than in those without (P = 0.024). SGF was present at 12 months in 9 of 22 eyes with CCT values > 410 μm at 1 week after starting treatment, in contrast with none of 17 eyes with CCT ≤ 410 μm at this time (P = 0.003). Conclusions: The current study suggested the potential validity of early post-treatment CCT as a feasible index to alert future progression to SGF in patients with VKH disease treated using systemic corticosteroids. [ABSTRACT FROM AUTHOR]

N parallel-connected SiC MOSFETs were investigated to apply to solid-state circuit breakers (SSCB), and it is an extension of a method that was proved valid by experiment of two parallel-connected SiC MOSFETs. The unclamped inductive switching (UIS) test was considered as the emergency interruption of SSCBs in this research. Because of the variations of breakdown voltage among SiC MOSFETs, the current flowing through devices is imbalanced during emergency interruption of SSCBs, which can drive some of the devices into thermal destruction prematurely. There are many compound cases for several SiC MOFETs with a certain maximum breakdown voltage variation. And the worst case, where the breakdown voltage of one device is assumed as the lowest, whereas the other devices have the same breakdown voltage, was extracted from the calculated results of four parallel-connected situation. In the worst case, it was found that the relation of breakdown voltage variations and current capacity is linear. Moreover, the distributions of breakdown voltage were taken as normal distributions. Using the worst case and distributions, a linear relation of breakdown voltage distributions and rated current of an SSCB could be concluded as a function of paralleled-connected numbers (N). Utilizing the function, the necessary breakdown voltage distributions and N of SiC MOSFETs can be evaluated for SSCBs meeting a certain yield ratio and current. • Design method of solid-state circuit breakers with parallel-connected SiC MOSFET • Clarifying acceptable breakdown voltage between parallel-connected SiC MOSFET in the unclamped inductive tests • Taking the breakdown voltage distribution as a normal distribution to calculate the yield of solid-state circuit breakers [ABSTRACT FROM AUTHOR]

Purpose: To quantitatively examine changes in choroidal circulation hemodynamics in patients with acute posterior multifocal placoid pigment epitheliopathy (APMPPE). Methods: Retrospective observational case series. Five eyes of 3 APMPPE patients were included. In all APMPPE eyes, laser speckle flowgraphy was conducted to evaluate the mean blur rate (MBR), a quantitative index of relative blood flow velocity. The changes in MBR at the initial visit and after 3 and 6 months were statistically analyzed. In 2 eyes, enhanced depth imaging optical coherence tomography was used to measure central choroidal thickness. Results: In all eyes, multiple subretinal placoid lesions spontaneously regressed with recovery of outer retinal morphology. The average MBR significantly increased at 3 and 6 months after baseline at the fovea by 49.6 and 54.2 % and at the lesion site by 65.2 and 70.8 %, respectively. These changes at both regions during the 6-month follow-up were statistically significant ( P = 0.02 for each). The mean central choroidal thickness decreased with time (518.0 µm at baseline to 344.5 µm at 6 months). Conclusions: Our data revealed the significant elevation of choroidal blood flow velocity and the substantial reduction of choroidal thickness with regression of APMPPE, suggesting that impaired choroidal circulation is involved in the pathogenesis of APMPPE. [ABSTRACT FROM AUTHOR]

Purpose: On the basis of angiographic features, it is suggested that choroidal circulation disturbance may be involved in the pathogenesis of multiple evanescent white dot syndrome (MEWDS). The aim of this study is to quantitatively evaluate changes in choroidal circulation hemodynamics using laser speckle flowgraphy (LSFG) in patients with MEWDS. Methods: Twelve eyes of 12 patients with MEWDS and 12 unaffected fellow eyes as controls were included. The macular mean blur rate (MBR), a quantitative index of relative blood flow velocity in the choroid, was measured by LSFG. Sequential changes in the average MBR values at the macula with granular changes and the lesion area with white dots were analysed. Moreover, correlations between the MRR changing rate and initial visual functions were examined. Results: Visual functions significantly improved 3 months after initial visit with accompanying improvements in outer retinal morphology. When compared with the baseline measurements, the MBR significantly increased at the macula of the affected eyes by 20.2 % and 13.0 % at 1 and 3 months respectively ( P < 0.01 for both), while no significant change was detected in fellow eyes. Similarly, the MBR increased at the lesion area by 17.8 % and 12.0 % at 1 and 3 months respectively ( P < 0.05 for both). Notably, the macular MBR elevation at 1 month was negatively correlated with both initial best-corrected visual acuity and the average threshold at the macula on Humphrey perimetry at baseline ( R = −0.76, P = 0.003; R = −0.60, P = 0.03, respectively), suggesting a close link between initially reduced choroidal blood flow and functional abnormalities at the onset of MEWDS. Conclusions: These results, in concert with angiographic findings, are likely to reinforce the concept of choroidal circulation impairment as a predisposing factor for MEWDS. [ABSTRACT FROM AUTHOR]

Purpose: To investigate sequential post-operative thickness changes in inner and outer retinal layers in eyes with an idiopathic macular hole (MH). Methods: Retrospective case series. Twenty-four eyes of 23 patients who had received pars plana vitrectomy (PPV) for the closure of MH were included in the study. Spectral domain optical coherence tomography C-scan was used to automatically measure the mean thickness of the inner and outer retinal layers pre-operatively and up to 6 months following surgery. The photoreceptor outer segment (PROS) length was measured manually and was used to assess its relationship with best-corrected visual acuity (BCVA). Results: Compared with the pre-operative thickness, the inner layers significantly thinned during follow-up (P = 0.02), particularly in the parafoveal (P = 0.01), but not perifoveal, area. The post-operative inner layer thinning ranged from the ganglion cell layer to the inner plexiform layer (P = 0.002), whereas the nerve fiber layer was unaltered. Outer layer thickness was significantly greater post-operatively (P = 0.002), and especially the PROS lengthened not only in the fovea but also in the parafovea (P < 0.001). Six months after surgery, BCVA was significantly correlated exclusively with the elongated foveal PROS (R = 0.42, P = 0.03), but not with any of the other thickness parameters examined. Conclusions: Following PPV for MH, retinal inner layers other than the nerve fiber layer thinned, suggestive of subclinical thickening in the inner layers where no cyst was evident pre-operatively. In contrast, retinal outer layer thickness significantly increased, potentially as a result of PROS elongation linking tightly with favorable visual prognosis in MH eyes. [ABSTRACT FROM AUTHOR]

Purpose: The pathogenesis of unilateral acute idiopathic maculopathy (UAIM) is unknown. The aim of this study was to quantitatively examine changes in choroidal circulation hemodynamics in patients with UAIM. Methods: This was a retrospective observational case-series which included five eyes of four patients with UAIM. All UAIM eyes and the fellow eyes in remaining three patients were studied using laser speckle flowgraphy (LSFG) to evaluate the mean blur rate (MBR), a quantitative index of relative blood flow velocity. The changes in MBR between the initial visit and after 1 and 3 months were statistically analyzed. Subfoveal choroidal thickness was measured in three UAIM eyes by enhanced depth imaging optical coherence tomography. Results: The mean logMAR value of best-corrected visual acuity in the UAIM eyes significantly improved ( P = 0.04) with recovery of outer retinal morphology. The average MBR of the UAIM eyes significantly increased at 1 (+21.7 % baseline value; P = 0.003) and 3 months (+32.5 % baseline value; P = 0.001), whereas the fellow eyes did not show this tendency. The mean values of subfoveal choroidal thickness decreased with time (316.0 µm at baseline, 186.6 µm at 1 month, and 167.3 µm at 3 months). Conclusions: These results reveal that there is a significant elevation of choroidal blood flow velocity and substantial reduction of choroidal thickness with regression of UAIM, suggesting that impaired choroidal circulation may be involved in the pathogenesis of UAIM. [ABSTRACT FROM AUTHOR]

Background context Surgical site infection (SSI) is a serious postoperative complication. The incidence of SSIs is lower in clean orthopedic surgery than in other fields, but it is higher after spinal surgery, reaching 4.15% in high-risk patients. Several studies reported that triclosan-coated polyglactin 910 sutures (Vicryl Plus; Ethicon, Inc., Somerville, NJ, USA) significantly reduced the infection rate in the general surgical, neurosurgical, and thoracic surgical fields. However, there have been no studies on the effects of such coated sutures on the incidence of SSIs in orthopedics. Purpose To compare the incidence of wound infections after spinal surgery using triclosan-coated suture materials with that of noncoated ones. Study design/setting A retrospective, nonrandomized, and clinical study. Patient sample From May 2010 to April 2012, 405 patients underwent a spinal surgical procedure in the Department of Orthopedic Surgery of two university hospitals. Outcome measures The primary outcome was the number of wound infections and dehiscences. Methods Two hundred five patients had a conventional wound closure with polyglactin 910 suture (Vicryl) between May 2010 and April 2011 (Time Period 1 [TP1]), and 200 patients underwent wound closure with triclosan-coated polyglactin 910 suture (Vicryl Plus) between May 2011 and April 2012 (TP2). Statistical comparisons of wound infections, dehiscence, and risk factors for poor wound healing or infection were performed. None of the authors has any conflict of interest associated with this study. Results There were two cases of wound dehiscence in TP1 and one in TP2 (p=.509). Using noncoated sutures in TP1, eight patients (3.90%) had wound infections, whereas one patient (0.50%) had wound infections in TP2 (using triclosan-coated sutures); the difference was significant (p=.020). Conclusions The use of triclosan-coated polyglactin 910 sutures instead of polyglactin 910 sutures may reduce the number of wound infections after spinal surgery. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship between circulation hemodynamics and morphology in the choroid during systemic corticosteroid therapy for patients with Vogt-Koyanagi-Harada (VKH) disease. Methods: This retrospective case series includes 18 eyes of nine patients with VKH disease (two men and seven women; average age, 40.8 years) who received systemic corticosteroid therapy. Laser speckle flowgraphy (LSFG) and enhanced-depth imaging optical coherence tomography (EDI-OCT) were performed before treatment and at 1 week and 1 and 3 months after treatment. The average values of the mean blur rate (MBR) at the macula and the central choroidal thickness (CCT) were compared at each stage. Results: The changing rates of the average MBR significantly increased at all examinations after the start of treatment compared with the pre-treatment value with resolution of serous retinal detachment (SRD) ( P = 0.0002 for all). The CCT decreased significantly at all examinations after the start of treatment compared with the pre-treatment value ( P = 0.0002 for all). Changes in MBR and CCT during the 3-month follow-up period correlated significantly ( R = −0.5913, P = 0.0097). The best-corrected visual acuity at pre-treatment correlated significantly with the changing rate of the MBR from 0 to 3 months ( R = 0.5944, P = 0.0093) but not with CCT. Conclusions: Our data suggest that circulatory disturbances and increased thickness of the choroid relate to the pathogenesis of VKH disease with link mutually. LSFG is useful as an index for evaluating the choroiditis activity of VKH disease as well as EDI-OCT. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical features and investigate their relationship with visual function in Japanese patients with acute zonal occult outer retinopathy (AZOOR). Methods: Fifty-two eyes of 38 Japanese AZOOR patients (31 female and 7 male patients; mean age at first visit, 35.0 years; median follow-up duration, 31 months) were retrospectively collected: 31 untreated eyes with good visual acuity and 21 systemic corticosteroid-treated eyes with progressive visual acuity loss. Variables affecting the logMAR values of best-corrected visual acuity (BCVA) and the mean deviation (MD) on Humphrey perimetry at initial and final visits were examined using multiple stepwise linear regression analysis. Results: In untreated eyes, the mean MD at the final visit was significantly higher than that at the initial visit (P = 0.00002). In corticosteroid-treated eyes, the logMAR BCVA and MD at the final visit were significantly better than the initial values (P = 0.007 and P = 0.02, respectively). The final logMAR BCVA was 0.0 or less in 85% of patients. Variables affecting initial visual function were moderate anterior vitreous cells, myopia severity, and a-wave amplitudes on electroretinography; factors affecting final visual function were the initial MD values, female sex, moderate anterior vitreous cells, and retinal atrophy. Conclusions: Our data indicated that visual functions in enrolled patients significantly improved spontaneously or after systemic corticosteroids therapy, suggesting that Japanese patients with AZOOR have good visual outcomes during the follow-up period of this study. Furthermore, initial visual field defects, gender, anterior vitreous cells, and retinal atrophy affected final visual functions in these patients. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented discussing a case aimed at examining changes in morphology and circulation in the choroid of an acute macular neuroretinopathy (AMN) patients using enhanced-depth imaging optical coherence tomography (EDI-OCT) and laser speckle flowgraphy (LSFG).

The article discusses the results of a study on the treatment of a patient with serpiginous choroiditis. Topics discussed include the presence of impaired circulation in the thickened choroid, use of laser speckel flowgraphy for noninvasive evaluation of occular tissue circulation and mean blur rate calculation, visual acuities, choroidal inflammation, and results of fluorescein angiography.

Abstract: In the present study, we demonstrated that a surface nitride layer with high surface hardness and good cell attachment performance could be produced on an arbitrary area of a titanium (Ti) substrate by using focused pulsed Nd:YAG laser irradiation accompanied by nitrogen gas blow. A focused laser beam induced nitrogen plasma in the vicinity of the Ti substrate surface. This plasma made it possible to form a nitride layer with a sufficient thickness, even when the laser power was low. The produced surface layer was approximately 1100nm in thickness and was composed of TiN and Ti; the concentration of TiN eventually decreased with increasing depth. The hardness of the laser-treated surface was approximately 7.5GPa, which was approximately five times that of the untreated Ti surface. Furthermore, the surface wettability of the Ti substrate was drastically improved by treating it with focused laser, which enhanced the cell attachment performance of the substrate. We concluded that the surface nitriding process using focused pulsed Nd:YAG laser is an excellent surface modification technique for Ti materials that can simultaneously improve their wear resistance and cell attachment performance. [Copyright &y& Elsevier]

Abstract: A selective surface nitriding of titanium (Ti) is considered an innovative technique in the industry. Focused low-power pulsed Nd:YAG laser irradiation in nitrogen atmosphere is one of the most promising candidates. In the present study, to determine the optimal settings for the formation of practical nitride layers, the effects of nitrogen gas pressure, laser power, and the number of laser shots on layer thickness were investigated in detail. The thickness of the nitride layer is dominated by nitrogen gas pressure, and layer thickness abruptly increased when treated at atmospheric pressure. Laser power also affected layer thickness, which monotonically increased with increasing laser power. In addition, a specific number of laser shots are required to fabricate a thick nitride layer. The surface hardness of Ti laser-irradiated at a nitrogen pressure of 150kPa was approximately 15GPa, approximately ten times of that of untreated Ti. On the other hand, when treated at pressures below 75kPa, hardness value was approximately 2.5GPa; the benefits of the laser treatment were hardly observed. Nitrogen gas pressure was found to be the key factor in controlling layer thickness, and an atmospheric pressure is required to form a practical nitride layer. [Copyright &y& Elsevier]

Background To evaluate changes of choroidal circulation quantitatively using laser speckle flowgraphy in patients with acute zonal occult outer retinopathy. Design Retrospective observational case series. Participants Sixteen eyes of 11 acute zonal occult outer retinopathy patients: seven non-treated eyes with good visual acuity and nine systemic corticosteroid-treated eyes with progressive visual acuity loss. Six eyes with thyroid-associated ophthalmopathy receiving systemic corticosteroid therapy served as controls. Methods The mean blur rate, an index of quantitative relative blood flow velocity, in the affected area was measured by laser speckle flowgraphy. The changes of mean blur rate, best-corrected visual acuity and the average threshold at the affected area on Humphrey perimetry during 24-week follow up were analysed. Main Outcome Measures Mean blur rate, best-corrected visual acuity, and the average threshold. Results In non-treated eyes, the average mean blur rate significantly increased at 24 weeks, with a significant increase of the average threshold. In corticosteroid-treated eyes, the mean blur rates at 1, 4, 12 and 24 weeks were significantly higher than the pretreatment value, with significant improvement of best-corrected visual acuity and the average threshold. The increase in mean blur rate at 4 weeks in corticosteroid-treated acute zonal occult outer retinopathy eyes was significantly higher than that in corticosteroid-treated control eyes. Conclusions In eyes with acute zonal occult outer retinopathy, the mean blur rate at the affected area significantly increases along with improvement of visual functions. These results suggest that impaired choroidal circulation is involved in the pathogenesis of acute zonal occult outer retinopathy. [ABSTRACT FROM AUTHOR]

Purpose: To investigate postoperative thickness changes in the retinal layers in eyes with epiretinal membrane (ERM). Correlations between these changes and visual outcomes were also examined. Methods: Retrospective review of 25 eyes (24 patients) that had undergone pars plana vitrectomy for ERM and had a postoperative follow-up period ≥6 months. Optical coherence tomography (6 × 6 mm macular thickness map) was used to measure mean thickness of the inner and outer retinal layers 1 week and 1, 3, and 6 months following surgery. Photoreceptor outer segment (PROS) length was evaluated manually, and used to assess the association between best-corrected visual acuity (BCVA) and retinal layer thickness at the fovea. Results: At 1 week and 1, 3, and 6 months, retinal layer thickness was 388, 377, 362, and 352 μm for the whole layer; 133, 115, 107, and 101 μm for the inner layer; 138, 145, 147, and 148 μm for the outer layer; and 28, 35, 36, and 40 μm for the PROS length, respectively. In comparison to 1-week data, the inner layers were significantly thinner at 1 month and later, as was the thickness of the entire retina. Outer layer thickness and PROS length were also significantly thicker at these time points. Six months following surgery, BCVA was significantly correlated with an elongated PROS length ( R = 0.49, P = 0.01). Conclusion: Retinal outer layer thickness significantly increased following pars plana vitrectomy for ERM. Visual improvement was positively correlated with PROS length recovery. [ABSTRACT FROM AUTHOR]

Purpose: The precise mechanism causing acute macular neuroretinopathy (AMN) is still unknown. A recent report suggested that choroidal circulation impairment correlates with its pathogenesis. We report a rare case with simultaneous onset of AMN and central retinal vein occlusion (CRVO), which is a retinal circulation disorder. Methods: Case report. Results: A 44-year-old woman complained of central visual loss of the left eye for the previous 2 weeks. The patient's visual acuity was 0.5 in the left eye (OS). Fundoscopic examination revealed a wedge-shaped, dark reddish-brown lesion at the macula, and CRVO-like retinal hemorrhages OS. Fluorescein angiography revealed retinal vasculitis and hypofluorescence corresponding to the macular lesion. The patient's scanning laser ophthalmoscopy infrared imaging result led to a diagnosis of AMN. Two weeks after corticosteroid pulse therapy, her visual acuity improved to 1.2 OS, with improvement of macular findings and Humphrey perimetry. When the dose of oral corticosteroid was decreased, the AMN lesion worsened, with recurrence of retinal hemorrhages. Visual functions improved again after an increased dose of corticosteroid. Conclusion: These results suggest that circulatory disorders almost simultaneously occurred in choroidal and retinal vessels, resulting in the onset of both AMN and CRVO. [ABSTRACT FROM AUTHOR]

Purpose: To report the results of triple therapy with photodynamic therapy (PDT) (PDT combined with intravitreal injection of bevacizumab (IVB) and sub-tenon injection of triamcinolone acetonide (STTA)) for the treatment of age-related macular degeneration (AMD) in Japanese patients. Methods: This retrospective case series included 38 eyes of 38 patients with exudative AMD treated with PDT combined with IVB (1.25 mg) and STTA (40 mg). Retreatment was performed in the same manner with intervals of at least 3 months. All patients had been treatment naïve, with a follow-up period of 12 months. Best-corrected visual acuity (BCVA), macular retinal thickness (MRT) on optical coherence tomography, and the number of treatments were analyzed. Results: The mean logarithm of the minimum angle of resolution BCVA in patients treated with PDT triple therapy was 0.86 ± 0.55 at baseline and 0.62 ± 0.55 at 12 months ( p < 0.001). The mean MRT was 554.0 ± 202.6 μm at baseline and 205.1 ± 78.6 μm at 12 months ( p < 0.001). During the 1-year follow-up, the average number of PDT triple therapy (treatments per patient) was 1.1. No complications, for example increase in intraocular pressure, cataract, or endophthalmitis, were observed. Conclusions: In AMD patients, PDT triple therapy significantly improved visual acuity with a minimum number of treatments and a low risk of complications during the 1-year follow-up. [ABSTRACT FROM AUTHOR]

Purpose: The precise mechanism causing outer retinal damage in acute macular neuroretinopathy (AMN) remains unclear. In this study, choroidal blood flow velocity was quantitatively evaluated using laser speckle flowgraphy (LSFG) in a patient with AMN who received systemic corticosteroid therapy. Methods: Corticosteroids were systemically administrated across 4 months for an AMN patient. LSFG measurements were taken ten consecutive times before treatment and at 1 week and 1, 3, and 10 months after the onset of therapy. The square blur rate, a quantitative index of relative blood flow velocity, was calculated using LSFG in three regions: Square 1, the macular lesion with findings of severe multifocal electroretinography amplitude reduction, and Squares 2 and 3, funduscopically normal-appearing retinal areas with findings of moderate and mild multifocal electroretinography amplitude reduction, respectively. Results: The AMN lesion gradually decreased after treatment and improved results were detected on the Amsler chart, as well as on optical coherence tomography and scanning laser ophthalmoscopy. When the changing rates of the macular flow were compared with the mean square blur rate level before treatment (100%), 14.6%, 24.5%, 12.9%, and 16.3% increases were detected in Square 1 (macular lesion) at 1 week and 1, 3, and 10 months after treatment, respectively. Similarly, in Square 2 (normal-appearing area next to the lesion), 12.6%, 18.6%, 6.7%, and 8.3% increases were also noted at 1 week and 1, 3, and 10 months after treatment, respectively. In Square 3 (normal-appearing area apart from the lesion), 16.0%, 15.1%, 19.1%, and 3.8% increases were measured at 1 week and 1, 3, and 10 months after treatment, respectively. Conclusion: In a patient with AMN, choroidal blood flow velocity at the lesion site, which was examined with LSFG, sequentially increased during systemic corticosteroid therapy, together with improvement of visual function. The present findings suggest that choroidal circulation impairment relates to the pathogenesis of AMN, extending over a wider area in the posterior pole than the site of an AMN lesion per se. [ABSTRACT FROM AUTHOR]

An electrochemical device is proposed for high-throughput electrochemical detection that consists of 32 row and 32 column electrodes on a single glass substrate. The row and column electrodes are connected to interdigitated array (IDA) electrodes to form 1024 (32 × 32) addressable sensor points in the device. Electrochemical responses from each of the 1024 sensors were successfully acquired on the device within 1 min using redox cycling at individual IDA electrodes, which ensures application of the device to comprehensive, high-throughput electrochemical detection for enzyme-linked immunosorbent assay (ELISA), reporter gene assay for monitoring gene expressions, and DNA analysis. [ABSTRACT FROM AUTHOR]

Purpose: Polymorphisms of the NACHT [neuronal apoptosis inhibitory protein (NAIP), CIITA, HET-E, TP1] and leucine-rich repeat protein 1 ( NLRP1) gene are reported to be associated with susceptibility to vitiligo and several autoimmune diseases. Vogt-Koyanagi-Harada (VKH) disease is an autoimmune disorder affecting melanocytes in the skin, eyes, inner ear, and meninges. In this study, genetic associations between VKH disease and single-nucleotide polymorphisms (SNPs) surrounding the NLRP1 gene were investigated. Methods: Six SNPs (rs6502867, rs925597, rs3926687, rs2733359, rs878329, and rs4790796) near the NLRP1 gene, including noncoding regions, were sequenced by a direct method to genotype 167 Japanese patients with VKH disease and 187 healthy Japanese volunteers. Results: None of the six SNPs in the NLRP1 region were significantly associated with disease susceptibility or the ocular, neurological, and dermatological manifestations of VKH. Conclusions: Although skin manifestations are clinically similar between vitiligo and VKH disease, the genetic and immunological mechanisms of these two diseases may be different. [ABSTRACT FROM AUTHOR]

Purpose: To describe two patients with macular oedema secondary to tuberous sclerosis complex (TSC) who were treated with intravitreal bevacizumab injection. Methods: Interventional case reports. Bevacizumab 1.25 mg was injected into the vitreous of two patients with TSC-associated macular oedema / exudative retinal detachment. Vascular endothelial growth factor (VEGF) concentration in the vitreous fluid was measured by enzyme-linked immunosorbent assay (ELISA) in one of these patients. Results: Patient 1: a 22-year-old woman with TSC was diagnosed as having multiple retinal hamartomas in both eyes. Eleven years later, the patient developed macular oedema with epiretinal membrane formation in the right eye. The patient underwent pars-plana vitrectomy with retinal photocoagulation for retinal tumours. VEGF concentration in the vitreous fluid was high compared to that in patients without retinal vascular diseases. Recurrent macular oedema disappeared by intravitreal injection of bevacizumab. Patient 2: a 32-year-old woman with TSC-associated retinal hamartoma, temporally showing macular exudative retinal detachment, developed neovascularization originated from the tumour. By intravitreal bevacizumab injection, the tumour size reduced markedly with regression of neovascularization. Conclusion: These results suggest that VEGF derived from retinal hamartomas causes macular oedema associated with TSC. Intravitreal injections of bevacizumab may be a useful therapeutic option for macular oedema secondary to TSC. [ABSTRACT FROM AUTHOR]

High-voltage (> 400 V) GaN high-electron mobility transistors were fabricated using two types of heterostructures with different buffer layer structures. The buffer layer structure affected the crystal defect density in grown AlGaN/GaN heterostructure. The static on-resistance under low applied voltage was independent of the buffer layer structure because it has influence on the 2-D electron-gas density. On the other hand, drain leakage current through the grown layers and the dynamic on-resistance increase caused by the current collapse phenomena depended on the buffer layer structure. The leakage current was reduced by the AlN/n-GaN/AlN layers because of the potential barrier at the AlN/n-GaN interface and no-depletion n-GaN layer. In addition, the experimental results showed the dynamic on-resistance was increased with the edge dislocation density and was not influenced by the screw dislocation density. From these results, it can be expected that edge dislocation related to the electron trapping center, which must be reduced suppress the current collapse phenomena. [ABSTRACT FROM AUTHOR]

Purpose: Laser speckle flowgraphy (LSFG) can be used to non-invasively visualize the haemodynamics of choroidal circulation and the vascular pattern. The purpose of this study was to examine the ability of LSFG to quantitatively evaluate blood flow velocity at the macula in patients with Vogt–Koyanagi–Harada (VKH) disease before and after systemic corticosteroid therapy. Methods: Prednisolone (200 mg/day) was systemically administered in 10 VKH disease patients with serous retinal detachment at the macular area. The drug was gradually tapered to zero over a 6-month period. Laser speckle flowgraphy measurements were taken in the 20 eyes of these patients at their initial visit and at 1, 4 and 12 weeks after the onset of therapy. Square blur rate (SBR), a quantitative index of relative blood flow velocity, was calculated using LSFG. Results: Serous retinal detachment resolved within 4 weeks after treatment and visual acuities improved to > 1.0 in almost all cases. There were significant increases in average SBR at the macula at 4 weeks after treatment compared with at 1 week after treatment, and also at 12 weeks after treatment compared with at 4 weeks after treatment. Conclusions: These results suggest that systemic corticosteroid therapy improves inflammation-related impairment in choroidal blood flow velocity at the macula. Laser speckle flowgraphy can evaluate the effect of systemic corticosteroid therapy by enabling comparisons between measurements of blood flow velocity, which is considered to reflect inflammation activity in the choroid. [ABSTRACT FROM AUTHOR]

The dynamic on-resistance increase associated with the current collapse phenomena in high-voltage GaN high-electron-mobility transistors (HEMTs) has been suppressed by employing an optimized field-plate (FP) structure. The fabricated GaN-HEMTs of 600 V/4.7 A and 940 V/4.4 A for power-electronics applications employ a dual-FP structure consisting of a short-gate FP underneath a long-source FP. The measured on-resistance shows minimal increase during high-voltage switching due to increased electric-field uniformity between the gate and drain as a result of using the dual FP. The gate-drain charge Qgd for the fabricated devices has also been measured to provide a basis for discussion of the ability of high-speed switching operation. Although Qgd/A (A: active device area) was almost the same as that of the conventional Si-power MOSFETs, RONA was dramatically reduced to about a seventh of the reported 600-V Si-MOSFET value. Therefore, RON Qgd for 600-V device was reduced to 0.32 ΩnC, which was approximately a sixth of that for the Si-power MOSFETs. The high-voltage GaN-HEMTs have significant advantages over silicon-power MOSFETs in terms of both the reduced on-resistance and the high-speed switching capability. [ABSTRACT FROM AUTHOR]

A recessed-gate structure has been studied with a view to realizing normally off operation of high-voltage AlGaN/GaN high-electron mobility transistors (HEMTs) for power electronics applications. The recessed-gate structure is very attractive for realizing normally off high-voltage AlGaN/GaN HEMTs because the gate threshold voltage can be controlled by the etching depth of the recess without significant increase in on-resistance characteristics. With this structure the threshold voltage can be increased with the reduction of two-dimensional electron gas (2DEG) density only under the gate electrode without reduction of 2DEG density in the other channel regions such as the channel between drain and gate. The threshold-voltage increase was experimentally demonstrated. The threshold voltage of fabricated recessed-gate device increased to -0.14 V while the threshold voltage without the recessed-gate structure was about -4 V. The specific on-resistance of the device was maintained as low as 4 mΩ ∙ cm² and the breakdown voltage was 435 V. The on-resistance and the breakdown voltage tradeoff characteristics were the same as those of normally on devices. From the viewpoint of device design, the on-resistance for the normally off device was modeled using the relationship between the AlGaN layer thickness under the gate electrode and the 2DEG density. It is found that the MIS gate structure and the recess etching without the offset region between recess edge and gate electrode will further improve the on-resistance. The simulation results show the possibility of the on-resistance below 1 mΩ ∙ cm² for normally off AlGaN/GaN HEMTs operating at several hundred volts with threshold voltage up to + 1 V. [ABSTRACT FROM AUTHOR]

Purpose: To describe a patient with bilateral diffuse uveal melanocytic proliferation (BDUMP) and cancer-associated retinopathy (CAR). Design: Interventional case report. Methods: A 66-year-old woman developed progressive vision loss 4 months after total hysterectomy. Ophthalmologic examination, Western blot test of sera and aqueous humor, and immunohistochemistry of carcinoma cells were performed. Results: Testing revealed BDUMP and severe retinal dysfunction. Autoantibodies against recoverin and heat shock cognate protein 70 (hsc 70) were detected in serum. Cytoplasmic immunoreactivity for recoverin and hsc 70 was observed in endometrioid carcinoma cells. Conclusions: Simultaneous cases of BDUMP and CAR are rare. Aberrantly expressed recoverin and hsc 70 triggered serum autoantibody production, which caused photoreceptor degeneration. [Copyright &y& Elsevier]

Si-MOSFETs with the breakdown voltage of over 1000 V were demonstrated, for the first time, realizing low on-resistance below the theoretical Si limit. The fabricated MOSFETs have a semi-superjunction (SemiSJ) structure, which is the combination of a superjunction (SJ) structure and an n-bottom assisted layer. The SemiSJ MOSFETs realize both the high breakdown voltage of 1110 and 1400 V and the low on-resistance of 54 and 163 mΩcm2, respectively. The fabrication process for the high-voltage SemiSJ-MOSFET was completely equivalent to a 600-V class SJ-MOSFET process, which implies that a single optimized process for forming SJ structure for 600 V-class MOSFET can be used for a wide voltage range extending up to 1200 V MOSFET. Additionally the fabricated MOSFETs realized low Ron Qgd of 4.6 ΩnC for a 1110-V device and 13.1 ΩnC for a 1400-V device, and recovery characteristics of the body diode were softer than those for the SJ MOSFET. These results show the possibility of new Si power-MOSFET with a higher application voltage range. [ABSTRACT FROM AUTHOR]

Reported herein is a case of 62-year-old man who complained of blurred vision and ocular pain in his right eye. The patient was diagnosed with choroidal melanoma complicated by neovascular glaucoma (NVG) and total retinal detachment, and he underwent enucleation of the eye. The isolated tumor was 2.5 × 2.5 cm in size. It was accompanied by intratumoral calcification, and consisted of epithelioid and spindle melanoma cells. There were a variety of microvessels in the stroma of the iris. The expression of thymidine phosphorylase (dThdPase), an angiogenic factor, was examined immunohistochemically. Cytoplasmic immunoreactivity for dThdPase was more prominent in the epithelioid cells than in spindle tumor cells. Another case of choroidal melanoma without NVG had less marked immunoreactivity. These results suggest that the production of dThdPase by melanoma cells correlates with the pathogenesis of NVG. [ABSTRACT FROM AUTHOR]

The relation between Schottky gate leakage current and the breakdown voltage of AIGaN-GaN high-electron mobility transistors (HEMTs) is discussed based on the newly introduced simple, yet useful, surface defect charge model. This model represents the leakage current caused by the positive charge in the surface portion of AIGaN layer induced by process damage such as nitrogen vacancies. The new model has been implemented into a two-dimensional device simulator, and the relationship between the gate leakage current and the breakdown voltage was simulated. The simulation results reproduced the relationship obtained experimentally between the leakage current and the breakdown voltage. Further simulation and experiment results show that the break- down voltage is maintained even if the defect charge exists up to the defect charge density of 2.5 × 1012 cm-2, provided the field plate structure is adopted, while the breakdown voltage shows a sudden drop for the defect density over 5 × 1011 cm-2 without the field plate. This result shows that the field plate structure is effective for suppressing the surface charge influence on breakdown voltage due to the relaxation of the electric field concentration in the surface portion of the AIGaN layer. [ABSTRACT FROM AUTHOR]

High breakdown voltage AlGaN-GaN power high-electron mobility transfers (HEMTs) on an insulating substrate were designed for the power electronics application. The field plate structure was employed for high breakdown voltage. The field plate length, the insulator thickness and AlGaN layer doping concentration were design parameters for the breakdown voltage. The optimization of the contact length and contact resistivity reduction were effective to reduce the specific on-resistance. The tradeoff characteristics between the on-resistance and the breakdown voltage can be improved by the optimization of the above design parameters, and the on-resistance can be estimated to be about 0.6 mω · cm² for the breakdown voltage of 600 V. This on-resistance is almost the same as that for the device on a conductive substrate. [ABSTRACT FROM AUTHOR]

Purpose: compare the results of vitrectomy with or without arteriovenous (AV) crossing sheathotomy for macular edema associated with branch retinal vein occlusion (BRVO). Design: Interventional case series. Methods: A retrospective study of 36 eyes with BRVO-associated macular edema. Twenty eyes underwent AV sheathotomy (AS group), and 16 eyes underwent posterior vitreous detachment (PVD group). Best-corrected visual acuity (BCVA), fluorescein angiography (FA), and optical coherence tomography to determine foveal thickness were conducted preoperatively and at 12 months postoperatively. Results: The mean postoperative BCVAs were significantly better in both the AS and the PVD group (P = .008 and P = .001, respectively). Foveal thickness decreased significantly 1 month after surgery in both groups (P = .002 and P = .007) and continued to decrease up to 12 months. The postoperative mean BCVA and improvement of BCVA and foveal thickness were not significantly different for the two groups at any postoperative period. Postoperative FA showed reperfusion of the occluded vein in 10 eyes in the AS group and 2 eyes in the PVD group, and formation of shunt vessels at the AV crossing site or around the macular region in all of the other eyes of both groups. Conclusions: Both AV sheathotomy and simple PVD significantly reduced macular edema associated with BRVO. However, there was no significant difference in the improvement of macular function following either procedure. Postoperative improvement of retinal circulation by either reperfusion of the occluded vein or collateral vessel formation was found. This accounted for functional and morphologic improvements. [Copyright &y& Elsevier]