47 research outputs found

    Effect Of Nitric-Oxide Post-Oxidation Annealing On High-Temperature Oxidized 4H SiC.

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    Metal-Oxide-Semiconductor FETs using 4H-SiC have been investigated intensively because 4H-SiC semiconductor has excellent physical properties for power-device applications

    Altered gut microbiome plays an important role in AKI to CKD transition in aged mice

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    IntroductionThis study investigated the role of renal-intestinal crosstalk in the transition from acute kidney injury (AKI) to chronic kidney disease (CKD) in elderly individuals.MethodsUsing young and aged mice, we induced bilateral ischemia-reperfusion injury (IRI) and compared intestinal and kidney inflammation over 28 days. To determine the role of the microbiome in gut–kidney crosstalk, we analyzed the microbiome of fecal samples of the young vs. aged mice and examined the effects of probiotic supplementation.ResultsIn the post-IRI recovery phase, prolonged intestinal and renal inflammation along with dysbiosis were evident in aged vs. younger mice that was associated with severe renal dysfunction and fibrosis progression in aged mice. Probiotic supplementation with Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI alleviated intestinal inflammation but not intestinal leakage, characterized by decreased inflammatory cytokine levels and decreased infiltration of macrophages, neutrophils, and Th17 cells. This was associated with improved M1-dominant renal inflammation and ultimately improved renal function and fibrosis, suggesting that renal–intestinal crosstalk in aged mice contributes to the transition from AKI to CKD.DiscussionOur study findings suggest that exacerbation of chronic inflammation through the gut–kidney axis might be an important mechanism in the transition from AKI to CKD in the elderly

    Comparison of CT and 18F-FDG PET for Detecting Peritoneal Metastasis on the Preoperative Evaluation for Gastric Carcinoma

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    OBJECTIVE: The aim of our study was to compare the accuracy of CT and (18)FFDG PET for detecting peritoneal metastasis in patients with gastric carcinoma. MATERIALS AND METHODS: One-hundred-twelve patients who underwent a histologic confirmative exam or treatment (laparotomy, n = 107; diagnostic laparoscopy, n = 4; peritoneal washing cytology, n = 1) were retrospectively enrolled. All the patients underwent CT and (18)F-FDG PET scanning for their preoperative evaluation. The sensitivities, specificities and accuracies of CT and (18)FFDG PET imaging for the detection of peritoneal metastasis were calculated and then compared using Fisher's exact probability test (p < 0.05), on the basis of the original preoperative reports. In addition, two board-certified radiologists and two board-certified nuclear medicine physicians independently reviewed the CT and PET scans, respectively. A receiver-operating characteristic curve analysis was performed to compare the diagnostic performance of CT and (18)F-FDG PET imaging for detecting peritoneal metastasis. RESULTS: Based on the original preoperative reports, CT and (18)F-FDG PET showed sensitivities of 76.5% and 35.3% (p = 0.037), specificities of 91.6% and 98.9% (p = 0.035), respectively, and equal accuracies of 89.3% (p = 1.0). The receptor operating characteristics curve analysis showed a significantly higher diagnostic performance for CT (Az = 0.878) than for PET (Az = 0.686) (p = 0.004). The interobserver agreement for detecting peritoneal metastasis was good (kappa value = 0.684) for CT and moderate (kappa value = 0.460) for PET. CONCLUSION: For the detection of peritoneal metastasis, CT was more sensitive and showed a higher diagnostic performance than PET, although CT had a relatively lower specificity than did PET.ope

    Verification of Forecast Performance of a Rapid Refresh Wave Model Based on Wind–Wave Interaction Effect

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    In this study, we constructed a rapid refresh wave forecast model using sea winds from the Korea Local Analysis and Prediction System as input forcing data. The model evaluated the changes in forecast performance considering the influence of input wind–wave interaction, which is an important factor that determines forecast performance. The forecast performance was evaluated by comparing the forecast results of the wave model with the significant wave height, wave period, and wave direction provided by moored buoy observations. During the typhoon season, the model tended to underestimate the conditions, and the root mean square error (RMSE) was reduced by increasing the wind and wave interaction parameter. The best value of the interaction parameter that minimizes the RMSE was determined based on the results of the numerical experiments performed during the typhoon season. The forecast error in the typhoon season was higher than that observed in the analysis results of the non-typhoon season. This can be attributed to the variations of the wave energy caused by the relatively strong typhoon wind field considered in the wave model

    Seasonal Precipitation Variability and Non-Stationarity Based on the Evolution Pattern of the Indian Ocean Dipole over the East Asia Region

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    Non-linear behavioral links with atmospheric teleconnections were identified between the Indian Ocean Dipole (IOD) mode and seasonal precipitation over East Asia (EA) using statistical models. The analysis showed that the lower the lag time, the higher the correlation; more than a two-fold correlation for non-linear regression with a kernel density estimator than for the linear regression method. When the IOD peaked, a pattern of significant reductions in seasonal precipitation during the negative IOD period occurred throughout the Korean Peninsula (KP). The occurrence of the positive IOD was in line with the El Niño phenomenon and generated greater seasonal precipitation than only the positive IOD, which takes place from March to May. This change occurred more in the cold tongue El Niño than the warm pool El Niño, inducing much higher spring precipitation throughout the KP. When negative IODs and La Niña coincided, there was slightly greater precipitation from March to May compared to the sole occurrence of negative IODs. In positive (negative) IOD years, there was anti-cyclonic (cyclonic) circulation in the South China Sea (SCS), helping to transport moisture to EA. The composite precipitation anomalies in the positive (negative) IOD years show above (below) normal precipitation in southern China. In contrast, other parts of the EA experienced drier (humid) signals than normal years. In positive IOD years, the anti-cyclonic circulation strength of the Bay of Bengal and the SCS continued until autumn and spring of the following year. This shows possible remote connections between climate events related to the tropical Indian Ocean and variations in precipitation over EA

    Changes in Typhoon Activities and Regional Precipitation Variability over the Korean Peninsula according to Different Phases of El Niño

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    We analyzed typhoon activities such as tropical cyclone (TC) genesis position, movement routes and central pressure of typhoons, and changes in local patterns of rainfall stemming from TCs passing through the Korean domain. The results showed a remarkable difference in changes in typhoons that affect the Korean Peninsula (KP) during cold tongue (CT) and warm pool (WP) El Niño years. In particular, TCs that move through the ocean off Korea and the Kuroshio during WP El Niño years are relatively stronger than TCs formed during CT El Niño years. Furthermore, analysis of large-scale atmosphere-ocean dynamics showed better conditions for TC development and strengthening during WP El Niño years. TC-induced summer rainfall over major Korean river basins decreased from normal years during CT El Niño years (−3.94%) and increased over normal years during WP El Niño years (+33.92%). The results of this diagnostic study rely on short-term observations and relatively little data, but they suggest that CT/WP El Niño cycles influence TC activities and rainfall across the KP. The findings are important for reducing TC damage and ensuring a proper response to climate change in coupled human-environmental systems

    The impact of circulatory arrest with selective antegrade cerebral perfusion on brain functional connectivity and postoperative cognitive function

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    Abstract Aortic surgery is one of the most challenging types of surgeries, which is possibly related to cognitive sequelae. We aimed to investigate the changes in resting-state functional connectivity (rsFC) associated with intraoperative circulatory arrest (CA) in aortic surgery, exploring the relationship between the altered connectivity and postoperative cognitive functions. Thirty-eight patients participated in this study (14 with CA, 24 without). Functional magnetic resonance imaging was scanned on the fifth day after surgery or after the resolution of delirium if it was developed. We assessed the differences in the development of postoperative cognitive changes and rsFC between patients with and without CA. The occurrence of postoperative delirium and postoperative cognitive dysfunction was not significantly different between the patients with and without the application of CA. However, patients with CA showed increased in posterior cingulate cortex-based connectivity with the right superior temporal gyrus, right precuneus, and right hippocampus, and medial prefrontal cortex-based connectivity with the dorsolateral prefrontal cortex. The application of moderate hypothermic CA with unilateral antegrade cerebral perfusion is unlikely to affect aspects of postoperative cognitive changes, whereas it may lead to increased rsFC of the default mode network at a subclinical level following acute brain insults
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