1,775 research outputs found

    Enhanced blue photoluminescence realized by copper diffusion doping of ZnO thin films

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    ZnO thin films with blue photoluminescence (PL) have been fabricated through Cu diffusion doping. A CuOx-ZnO mixture, and Cu/ZnO double layer, films were prepared on amorphous SiOx/Si substrates by pulsed laser deposition (PLD), and electron beam (e-beam) deposition, respectively. After sequential oxygen annealing, CuOx-ZnO mixture films exhibited green emission centered at 523 nm. However, Cu/ZnO double layer films differed in producing a blue emission centered at 480 nm. Detailed analysis identified that this blue shift in the emission center resulted from increased blue emissions attributed to Cu dopants in the film by e-beam deposition. Luminescence intensity was increased to 6 cd/m2 for a sample annealed at 700 deg;C. Color points were close to the locus of points following the line of a black-body-radiator on the CIE 1931 XY chromaticity diagram. The present results show that Cu-doped ZnO has strong potential as a cost effective phosphor for use in down converting LEDs. © 2013 Optical Society of America.1

    Physical characterization of amorphous In-Ga-Zn-O thin-film transistors with direct-contact asymmetric graphene electrode

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    High performance a-IGZO thin-film transistors (TFTs) are fabricated using an asymmetric graphene drain electrode structure. A-IGZO TFTs (channel length = 3 μm) were successfully demonstrated with a saturation field-effect mobility of 6.6 cm2/Vs without additional processes between the graphene and a-IGZO layer. The graphene/a-IGZO junction exhibits Schottky characteristics and the contact property is affected not only by the Schottky barrier but also by the parasitic resistance from the depletion region under the graphene electrode. Therefore, to utilize the graphene layer as S/D electrodes for a-IGZO TFTs, an asymmetric electrode is essential, which can be easily applied to the conventional pixel electrode structure. © 2014 Author(s).1

    Use of a Tunneling Technique to Achieve a Lower Defibrillation Threshold during Implantable Cardioverter Defibrillator Implantation via the Right Subclavian Vein

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    A 56-yr-old man with aborted sudden cardiac death underwent implantable cardioverter defibrillator (ICD) implantation. While the ICD was being implanted, a left subclavian venogram failed to visualize the left subclavian vein, which was attributed to likely prolonged indwelling of the left subclavian sheath for venous access. Accordingly, the right subclavian vein was punctured and the ICD lead was diverted from the right side area to the active Can in the left pectoral area by tunneling over the sternum for high defibrillation threshold. The approach used in this case may be considered in patients who had difficult left subclavicular venous access and it may be prudent to save the left subclavian vein for ICD implantation in patients with fatal tachyarrhythmia

    Fabrication of n-type nanotube transistors with large-work-function electrodes

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    The authors found experimentally that carbon nanotube field-effect transistors (CNFETs) could exhibit n -type characteristics even though their electrodes consist of a large-work-function metal such as Co. To explain their result, which is contrary to the general belief that CNFETs with large-work-function electrodes always lead to p -type characteristics, ab initio electronic structure calculation for the metal-carbon nanotube junction was performed, which showed that the Fermi level alignment at the junction could sensitively depend on microscopic structures of the metal-carbon nanotube junction. This suggests that deposition method of electrodes as well as the metal type could be utilized to obtain n -type CNFETs.open121

    Successful Catheter Ablation of Atrial Tachycardia Originating from the Non-coronary Aortic Sinus

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    We report a rare case of atrial tachycardia originating from the non-coronary aortic sinus. After failed radiofrequency (RF) energy applications at right His-bundle region, the complete elimination of atrial tachycardia was achieved with an RF energy application in the non-coronary aortic sinus. With the review of other papers, this report emphasizes the importance of mapping in the non-coronary aortic sinus in focal atrial tachycardia near the atrioventricular node or near the Hisbundle

    Thyroid function in obese Korean children and adolescents: Korea National Health and Nutrition Examination Survey 2013–2015

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    Purpose In recent years, there has been an increasing focus on thyroid function in pediatric obese patients, but no nationwide study evaluating the relationship between thyroid function and obesity has yet been conducted in Korea. We aimed to evaluate thyroid dysfunction in obese Korean children. Methods We analyzed the associations between obesity and thyroid hormone levels among 975 Korean boys and girls aged 10–18 years and who participated in the Korean National Health and Nutrition Examination Survey VI (2013–2015). Results Average serum thyrotropin (TSH) and serum free thyroxine (fT4) levels in the nonobese group were 2.7±0.1 μIU/mL and 1.3±0.0 ng/dL, respectively, and those in the overweight group were 3.1±0.2 μIU/mL and 1.2±0.0 ng/dL. Serum TSH level was significantly higher in the abdominal obesity group than in the normal group (P=0.023). fT4 level was significantly lower in both the overweight and abdominal obesity groups than in the normal group (P<0.001, P=0.014). Serum TSH level was associated positively with abdominal obesity and levels of high-density lipoprotein cholesterol and triglyceride. Serum fT4 level was negatively correlated with abdominal obesity (P=0.014). Conclusions Korean children with abdominal obesity showed increased TSH and decreased fT4 levels compared to normal children

    The effect of low-dose intravenous bisphosphonate treatment on osteoporosis in children with quadriplegic cerebral palsy

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    PurposeQuadriplegic children with cerebral palsy are more susceptible to osteoporosis because of various risk factors that interfere with bone metabolism. Pamidronate is effective for pediatric osteoporosis, but there are no guidelines for optimal dosage or duration of treatment in quadriplegic children with osteoporosis. We aimed to evaluate the efficacy of low-dose pamidronate treatment in these patients.MethodsTen quadriplegic patients on antiepileptic drugs (6 male, 4 female patients; mean age, 10.9±5.76 years), with osteoporosis and gross motor function classification system level V, were treated with pamidronate (0.5–1.0 mg/kg/day, 2 consecutive days) every 3–4 months in a single institution. The patients received oral supplements of calcium and vitamin D before and during treatment. The lumbar spine bone mineral density (BMD) z score and biochemical markers of bone metabolism were measured regularly during treatment.ResultsThe main underlying disorder was perinatal hypoxic brain damage (40%, 4 of 10). The mean cumulative dose of pamidronate was 4.49±2.22 mg/kg/yr, and the mean treatment period was 10.8±3.32 months. The BMD z score of the lumbar spine showed a significant increase from −4.22±1.24 before treatment to −2.61±1.69 during treatment (P=0.008). Alkaline phosphatase decreased during treatmentn (P=0.037). Significant adverse drug reactions and new fractures were not reported.ConclusionLow-dose pamidronate treatment for quadriplegic children with cerebral palsy increased lumbar BMD and reduced the incidence of fracture

    MDR-1 gene expression is a minor factor in determining the multidrug resistance phenotype of MCF7/ADR and KB-V1 cells

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    AbstractThe relevance of MDR-1 gene expression to the multidrug resistance phenotype was investigated. Drug-resistant cells, KB-V1 and MCF7/ADR, constantly expressed mRNA of the MDR-1 gene and were more resistant to vinblastine and adriamycin than drug-sensitive cells, KB-3–1 and MCF7. The drug efflux rate of KB-V1 was the same as KB-3–1 although the MDR-1 gene was expressed in only the resistant cell. The higher intracellular drug concentration of KB-3–1 than KB-V1 was due to the large drug influx. In the case of MCF7 and MCF7/ADR, the influx and efflux of the drug had nearly the same pattern and drug efflux was not affected by verapamil. The amount of ATP, cofactor of drug pumping activity of P-glycoprotein, was not changed by the resistance. These observations suggested that drug efflux mediated by MDR-1 gene expression was not a major determining factor of drug resistance in the present cell systems, and that the drug resistance could be derived from the change in drug uptake and other mechanisms
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