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ABSTRACT: Concerning the oxidation behavior of Si1-xGe(x) (x = 0.15, 0.3) nanowires at high temperature, Si1-xGe(x) nanowires were thermally oxidized for various lengths of time compared with Si nanowires, Si and Si1-xGe(x) thin films. The structural and compositional properties of the oxidized nanowires were characterized using several transmission electron microscopy (TEM) techniques including energy dispersive X-ray spectroscopy (EDS), which confirm that the oxidation rates of Si1-xGe(x) and Si (silicon) nanowires were saturated with increasing oxidation time due to retarding behavior, while the oxidation rate of Si1-xGe(x) nanowires were faster than that of Si nanowires. In addition, the differences in Ge (germanium) content and stress distribution contribute to the observed differences in oxidation behavior.
Journal of Nanoscience and Nanotechnology 07/2012; 12(7):6096-9. · 1.56 Impact Factor
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ABSTRACT: For this investigation of the Ge behavior of condensed Si(1-y)Ge(y) (y > x) cores during the oxidation of Si(1-x)Ge(x) nanowires, Si(1-x)Ge(x) nanowires were grown in a tube furnace by the vapor-liquid-solid method and thermally oxidized. The test results were characterized using several techniques of transmission electron microscopy. The two types of Ge condensation are related to the diameter and Ge content of the nanowires. The consumption of Si atoms in prolonged oxidation caused the condensed SiGe cores to become Ge-only cores; and the continuous oxidation resulted in the oxidation of the Ge cores. The oxidation of Ge atoms was confirmed by scanning transmission electron microscopy.
Journal of Nanoscience and Nanotechnology 04/2012; 12(4):3650-4. · 1.56 Impact Factor
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Hang Lak Lee,
Chang Soo Eun,
Oh Young Lee,
Yong Cheol Jeon,
Dong Soo Han,
Ju Hyun Sohn,
Byung Chul Yoon,
Ho Soon Choi,
Joon Soo Hahm,
Min Ho Lee,
Dong Hoo Lee,
Won Moon, Sang-Yeon Kim
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ABSTRACT: According to a previous study, a longer insertion time was associated with inadequate bowel cleansing, advanced age, constipation, surgical history, sex, and a low body mass index. However, there are only a few studies on the association between cecal insertion time and colonoscope length (long vs intermediate).
To assess the association of colonoscope length and cecal insertion time.
Prospective comparative trial, with systematic assignment to colonoscope length.
A total of 998 colonoscopic examinations were performed by a single endoscopist, who used video colonoscopes.
Cecal insertion times and their potential covariates.
The mean (+/-SEM) age was 49.06 +/- 0.4 years, 61% were men, and the mean (+/-SEM) body mass index was 24.17 +/- 2.96. The mean (+/-SEM) cecal insertion time was 4.68 +/- 0.09 minutes. Multivariate regression analysis demonstrated that sex (female, P = .000), colonoscope length (long, P = .000), increasing age (P = .000), percentage of body fat (P = .006), and inadequate bowel cleansing (P = .002) were independent factors associated with a longer insertion time.
All procedures were performed by only one gastroenterologist, so the individual characteristics of colonoscopic procedures could be affected by a consequent bias.
This large, cross-sectional study identified colonoscope length as a useful factor that affected cecal insertion time.
Gastrointestinal endoscopy 02/2009; 69(3 Pt 1):503-8. · 6.71 Impact Factor
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Ji Eun Yun,
Jae Woong Sull,
Hee Yeon Lee,
Eunjung Park,
Soriwool Kim,
Jaeseong Jo,
Sun Ju Lee, Sang Yeon Kim,
Young Ju Choi,
Sun Ha Jee,
Kap Bum Huh
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ABSTRACT: Although adiponectin is generally known as a predictor of metabolic syndrome, potential of adiponectin as a predictor for metabolic syndrome in type 2 diabetes is debated. The purpose of this study is to determine the association between adiponectin and metabolic syndrome in patients with type 2 diabetes.
Adiponectin and the risk of metabolic syndrome were examined among 1013 type 2 diabetes patients who visited Huh's Diabetes Center from January 2003 to June 2006. Adiponectin levels were classified into quartile groups, and metabolic syndrome was defined according to the standard of National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III. Insulin sensitivity was directly assessed using the short insulin tolerance test (SITT) (Kitt: %/ min).
Adiponectin was significantly correlated with metabolic syndrome components. The age-adjusted correlations between adiponectin and clinical parameters including metabolic components were significant; adiponectin was negatively correlated with waist circumference, diastolic blood pressure and triglyceride, and positively correlated with high-density lipoprotein (HDL) cholesterol. Subjects with metabolic syndrome showed lower adiponectin levels than those without metabolic syndrome. After multivariate adjustment, participants with lower adiponectin levels also had a higher risk for metabolic syndrome (OR for lowest quartiles 2.21; 95% CI, 1.51-3.24). Metabolic syndrome risk was stronger among those with low adiponectin and severe insulin resistance simultaneously. This study has shown additive effects of adiponectin and insulin resistance on metabolic syndrome.
In type 2 diabetic patients, the adiponectin was a useful predictor of metabolic syndrome independent of potential confounding variables.
Diabetes/Metabolism Research and Reviews 02/2009; 25(3):259-65. · 3.37 Impact Factor
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ABSTRACT: Monocyte adhesion to vascular endothelium is an initial step in atherogenesis. To quantify this, we incubated monocytes with cultured endothelial cells, and quantified the adhered live monocytes using a colorimetric assay. Endothelium activated with lipopolysaccharide attracted monocytes in a dose-dependent manner and the adhesion was attenuated with post-treatments with L-ascorbic acid (53%), alpha- (40%) and gamma-tocopherol (39%), resveratrol (39%), and Lithospermum erythrorhizon root extract (45%). This non-radioactive, colorimetric assay may be useful for screening anti-atherogenic compounds in early atherogenesis.
Biotechnology Letters 12/2006; 28(22):1805-10. · 1.68 Impact Factor
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ABSTRACT: Genistin has antioxidant activities; however, its insolubility in water often limits its biological availability in vivo. Using a novel transglycosylation process, the solubility of genistin glycosides was increased 1000 to 10000-fold, but it was not known whether these modified genistin glycosides maintained antioxidant activity. We found that both genistin and its glycosides similarly up-regulated the transcription of several metallothionein (MT) antioxidant genes (MT1A, MT2A, MT1E, and MT1X), as well as the glucose 6-phosphate dehydrogenase (G6PD) gene in HepG2 cells. This gene induction was mediated by the sequestration of zinc in the cytosol, which up-regulated the metal-responsive transcription factor-1 (MTF-1) that induced MT gene expression. Although not as effective as ascorbic acid, genistin glycosides possessed slightly greater reducing power than genistin. We concluded that genistin and genistin glycosides have a direct antioxidant effect and an indirect antioxidant effect, perhaps via induction of MT by activity of MTF-1.
Journal of Agricultural and Food Chemistry 06/2006; 54(11):3819-26. · 2.82 Impact Factor
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ABSTRACT: We present a new image contrast enhancing method based on the
piecewise-linear approximation of the cumulative density function (CDF).
Reduced hardware is required for CDF calculation, since the number of
bins is greatly reduced thanks to this approximation. With the proposed
method, various contrast enhancing effects can be implemented such as
histogram equalization, partial or entire histogram modification
IEEE Transactions on Consumer Electronics 09/1999; · 0.94 Impact Factor
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ABSTRACT: In this paper, we designed 3D graphics rasterizer with a culling and clipping for the efficient 3D graphics accelerator. The proposed rasterizer is implemented for the mobile system and process frustum culling, back face culling, Y-axis clipping and X-axis clipping. The rasterzier consists of triangle setup, edge walk and span process unit. Each unit of rasterzier is designed with a culling and clipping. It supports goraud shading with 16-bit depth values and 16-bit color values. The estimated performance of proposed rasterizer is 52M pixels per second.
TENCON 2007 - 2007 IEEE Region 10 Conference;
