Temperature dependence of Mott transition in VO_2 and programmable critical temperature sensor

The temperature dependence of the Mott metal-insulator transition (MIT) is studied with a VO_2-based two-terminal device. When a constant voltage is applied to the device, an abrupt current jump is observed with temperature. With increasing applied voltages, the transition temperature of the MIT current jump decreases. We find a monoclinic and electronically correlated metal (MCM) phase between the abrupt current jump and the structural phase transition (SPT). After the transition from insulator to metal, a linear increase in current (or conductivity) is shown with temperature until the current becomes a constant maximum value above T_{SPT}=68^oC. The SPT is confirmed by micro-Raman spectroscopy measurements. Optical microscopy analysis reveals the absence of the local current path in micro scale in the VO_2 device. The current uniformly flows throughout the surface of the VO_2 film when the MIT occurs. This device can be used as a programmable critical temperature sensor.Comment: 4 pages, 3 figure

Spontaneous Tumor Lysis Syndrome Presenting Acute Kidney Injury with Extreme Hyperuricemia and Urinary Stone: A Rare Case of Spontaneous Tumor Lysis Syndrome

Tumor lysis syndrome is a serious complication of malignancy, resulting from the massive and rapid release of cellular components into the blood. Generally, it occurs after initiation of chemotherapy. The onset of spontaneous tumor lysis syndrome (STLS) before anti-cancer treatment is rare and occurs mostly in Burkitt lymphoma and non-Hodgkin’s lymphoma. There are only a few case reports in children. Here, we report a case of STLS secondary to T-cell acute lymphoblastic leukemia (ALL), which presented with urinary stone and subsequent acute kidney injury with severe hyperuricemia. Occult malignancy should be considered in case of unexplained acute kidney injury with extreme hyperuricemia

Intrapulmonary Cystic Lymphangioma in a 2-month-old Infant

Lymphangioma is an abnormal collection of lymphatics that are developmentally isolated from the normal lymphatic system. Lymphangioma rarely presents as a solitary pulmonary lesion. We report a rare case of intrapulmonary cystic lymphangioma involving the upper lobe of the right lung, which presented with dyspnea in a 2-month-old infant. High-resolution computed tomography (HRCT) of the chest demonstrated a well-circumscribed, multiseptate, cystic lesion in the upper lobe of the right lung, mimicking the feature of type I congenital cystic adenomatoid malformation. The tumor was removed by bilobectomy of the upper and middle lobes of the right lung, and its pathologic examination confirmed the diagnosis of an intrapulmonary cystic lymphangioma

Advanced fibrosis is not a negative pretreatment predictive factor for genotype 2 or 3 chronic hepatitis C patients

Background/AimsChronic hepatitis C patients with advanced fibrosis have unsatisfactory sustained virological response (SVR) rates. Few data demonstrating the efficacy of combination therapy in chronic hepatitis C patients with advanced fibrosis in South Korea are available. The purpose of this study was to assess whether the stage of fibrosis impacts the efficacy of combination therapy for chronic hepatitis C.MethodsWe retrospectively reviewed data for a total of 109 patients with chronic hepatitis C, treated with peginterferon alfa and ribavirin. SVR according to the stage of liver fibrosis assessed by pretreatment liver biopsy and genotype results were analyzed.ResultsData from 66 genotype 1 patients (60.6%) and 43 genotype 2 or 3 patients (39.4%) among the 109 patients were analyzed. SVR rates for the genotype 1 patients were significantly lower for the stage 3-4 group (32.1%) than the stage 0-2 group (78.9%; P<0.001). SVR rates (92.0% for stage 0-2, 77.8% for stage 3-4, P=0.184) of genotype 2 or 3 patients were not significantly different according to fibrosis stage. Likewise, the frequency of adverse events was not significantly different according to fibrosis stage.ConclusionsCompared to patients without advanced fibrosis, we can anticipate good SVR rates for genotype 2 or 3 patients with advanced fibrosis and they did not show an inferior tolerability for peginterferon and ribavirin combination therpy. Our results suggest that active treatment is needed for genotype 2 or 3 patients with advanced fibrosis

The Relationship Between Coronary Artery Calcification and Bone Mineral Density in Patients According to Their Metabolic Syndrome Status

Background and Objectives: The extent of coronary artery calcification (CAC) is closely related to total atherosclerotic plaque burden. However, the pathogenesis of CAC is still unclear. Conditions such as diabetes mellitus, renal failure, smoking, and chronic inflammation have been suggested to link vascular calcification and bone loss. In the present study, we hypothesized that bone loss can contribute to the pathogenesis of CAC in patients with the chronic inflammatory condition that accompanies metabolic syndrome (MetS). The objective of this study was to investigate the relationship between CAC and bone mineral density (BMD) in patients with MetS and in patients without MetS, by using coronary multidetector-row computed tomography (MDCT). Subjects and Methods: Data from 395 consecutive patients was analyzed retrospectively. From the MDCT database, only those patients who underwent both coronary MDCT and dual-energy X-ray absorptiometry within an interval of one month, were selected. The presence of MetS was determined by the updated criteria as defined by the Third Adult Treatment Panel Report of the National Cholesterol Education Program. Results: In patients with MetS, a significant correlation was found between CAC and age {odds ratio (OR)=1.139, 95% confidence interval (CI) 1.080 to 1.201, p&lt;0.001}, CAC and male sex (OR=3.762, 95% CI 1.339 to 10.569, p=0.012), and CAC and T-score of L-spine (OR=0.740, 95% CI 0.550 to 0.996, p=0.047) using a forward multiple logistic regression analysis model including clinical variables of gender, age, lipid profile, body mass index, diabetes mellitus, hypertension, smoking, and BMD. But in patients without MetS, BMD by itself was not found to contribute to CAC. Conclusion: BMD was inversely correlated with CAC only in patients with MetS. This finding suggests that low BMD accompanied by MetS, may have significant clinical implications

Non-Dipper Pattern is a Determinant of the Inappropriateness of Left Ventricular Mass in Essential Hypertensive Patients

Background and Objectives: Inappropriately high left ventricular mass (iLVM) is known to be related to cardiovascular prognosis. A non-dipper pattern has a greater mean left ventricular (LV) mass than the dipper pattern in hypertensive patients. However, the appropriateness of LV mass in dipper or non-dipper patterns has not been adequately investigated. The aim of this study was to define the relationship between nocturnal dipping and the appropriateness of LV mass. Subjects and Methods: Using the ambulatory blood pressure monitoring (ABPM) database, the data of 361 patients who underwent ABPM and echocardiography was analyzed retrospectively. Appropriateness of LV mass was calculated as observed/predicted ratio of LV mass (OPR) using a Korean-specified equation. Nocturnal dipping was expressed as percent fall in systolic blood pressure (BP) during the night compared to the day. Results: Daytime, nighttime and 24 hours BP in hypertensive patients was 140.4 +/- 14.8 mmHg, 143.7 +/- 15.2 mmHg and 129.4 +/- 20.0 mmHg, respectively. OPR was 106.3 +/- 19.9% and nocturnal dipping was 10.2 +/- 10.9 mmHg. In a multiple linear regression model, 24 hours systolic BP (beta=0.097, p=0.043) and nocturnal dipping (beta=-0.098, p=0.046) were independent determinants of OPR as well as age (beta=0.130, p=0.025) and body mass inde

The Relationship Between Ambulatory Arterial Stiffness Index and Blood Pressure Variability in Hypertensive Patients

Background and Objectives: Ambulatory arterial stiffness index (AASI) is well known as a predictor of cardiovascular mortality in hypertensive patients. Mathematically, AASI reflect the standard deviation (SD) of blood pressure (BP) variation. AASI is measured higher levels in non-dipper than dipper. Thus, AASI has a possibility of not only reflecting arterial stiffness but also BP variability and/or autonomic nervous dysfunction. Subjects and Methods: Consecutive data from 418 untreated hypertensive patients were analyzed retrospectively. We examined the association between the 24-hour ambulatory BP monitoring (ABPM) parameters and AASI. Results: AASI had a simple correlation with age (R=0.189, p&lt;0.001), relative wall thickness (RWT) (R=0.115, p=0.019), left ventricular mass index (LVMI) (R=0.192, p&lt;0.001), average systolic BP (SBP) (R=0.232, p&lt;0.001), average pulse pressure (PP) (R=0.363, p&lt;0.001), SD of diastolic BP (DBP) (R=-0.352,p&lt;0.001), SD of PP (R=0.330, p&lt;0.001), SD of heart rate (HR) (R=-0.268, p&lt;0.001), and nocturnal dipping (R=-0.137, p=0.005). In multiple linear regression analysis model including clinical parameters and 24 hour-ABPM parameters, independent predictors of AASI were SD of PP (beta=1.246, p&lt;0.001), SD of DBP (beta=-1.067, p&lt;0.001), SD of SBP (beta=-0.197, p&lt;0.001), and non-dipper (beta=0.054, p=0.033). Conclusion: AASI is closely correlated with BP variability. The result of this study shows that AASI is not only a parameter for arterial stiffness, but also a parameter for BP variability