707 research outputs found

    Seismic Strengthening Effects Based on Pseudodynamic Testing of a Reinforced Concrete Building Retrofitted with a Wire-Woven Bulk Kagome Truss Damper

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    A passive damper with a wire-woven bulk Kagome truss design was recently developed; its applicability as a passive damper to improve the seismic performance of building systems, including shear hysteresis behavior, energy dissipation capacity, and fatigue, was confirmed by material tests. The Kagome truss, a periodic cellular metal type, is composed of evenly distributed helical wires with a constant pitch and helical radius in six directions. The purpose of this study was to develop a new passive damper system for seismic strengthening of existing reinforced concrete (RC) frames. The proposed external connection methodology uses a wire-woven bulk Kagome truss (i.e., a Kagome damper external connection (KDEC) system), to dissipate earthquake energy using the dynamic interaction among an existing building, a support structure, and the Kagome damper installed between them. Four test specimens were designed and then strengthened with the KDEC system. Cyclic loading and pseudodynamic tests were conducted; lateral load-carrying capacity, deformation, and hysteresis characteristics were investigated, as well as the maximum response strength, response ductility, and earthquake damage degree, and compared to a control sample. Test results revealed that the KDEC system effectively dissipated the earthquake energy, showing considerable resilience under large-scale earthquake conditions

    Growth of ultra-uniform graphene using a Ni/W bilayer metal catalyst

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    We investigated a bilayer catalyst system consisting of polycrystalline Ni and W films for growing mono-layer graphene over large areas. Highly uniform graphene was grown on Ni/W bilayer film with 100% coverage. The graphene grown on Ni/W bilayer film and transferred onto an insulating substrate exhibited average hole and electron mobilities of 727 and 340 cm(2)V(-1)s(-1), respectively. A probable growth mechanism is proposed based on X-ray diffractometry and transmission electron microscopy, which suggests that the reaction between diffused carbon and tungsten atoms results in formation of tungsten carbides. This reaction allows the control of carbon precipitation and prevents the growth of non-uniform multilayer graphene on the Ni surface; this has not been straightforwardly achieved before. These results could be of importance in better understanding mono-layer graphene growth, and suggest a facile fabrication route for electronic applications. (C) 2015 AIP Publishing LLCopen0

    Renal Artery Embolization of Perirenal Hematoma in Hemorrhagic Fever with Renal Syndrome: A Case Report

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    Hemorrhagic fever with renal syndrome (HFRS) is an acute viral disease characterized by fever, hemorrhage and renal failure. Among the various hemorrhagic complications of HFRS, spontaneous rupture of the kidney and perirenal hematoma are very rare findings. We report here on a case of HFRS complicated by massive perirenal hematoma, and this was treated with transcatheter arterial embolization

    Carriage of Cytochrome 2C19 Polymorphism Is Associated With Risk of High Post-Treatment Platelet Reactivity on High Maintenance-Dose Clopidogrel of 150 mg/day Results of the ACCEL-DOUBLE (Accelerated Platelet Inhibition by a Double Dose of Clopidogrel According to Gene Polymorphism) Study

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    ObjectivesThis study sought to determine the impact of gene polymorphisms on platelet reactivity (PR) after clopidogrel 150 mg/day in patients treated with percutaneous coronary intervention (PCI).BackgroundAlthough high maintenance-dose (MD) clopidogrel reduces PR, it is unknown whether gene polymorphisms are related with the risk of high post-treatment PR (HPPR) after high-MD clopidogrel.MethodsWe included mostly patients receiving high-MD clopidogrel after PCI from previously registered Gyeongsang National University Hospital data. A total of 126 PCI-treated patients receiving high-MD clopidogrel were enrolled. Platelet reactivity was assessed with conventional aggregometry and VerifyNow (Accumetrics Inc., San Diego, California) after receiving clopidogrel 150 mg/day for at least 1 month. CYP3A5, CYP2C19, and ABCB1 genotyping was performed. We defined HPPR as 5 μmol/l adenosine diphosphate (ADP)–induced maximal PR (PRmax) >50%.ResultsCYP3A5 and ABCB1 polymorphisms did not influence PR. Carriers of CYP2C19 variant (*2 or *3) (n = 80) had significantly higher 5 and 20 μmol/l ADP-induced PRmax than did noncarriers (n = 46) (40.7 ± 16.8% vs. 30.3 ± 12.6%, p < 0.001; 54.2 ± 16.2% vs. 40.5 ± 15.8%, p < 0.001, respectively). Late PR and VerifyNow results indicated consistently greater measures in carriers versus noncarriers of CYP2C19 variant. All platelet measures proportionally increased according to the number of CYP2C19 variant alleles. Twenty-seven (21.4%) patients met the criteria for HPPR. Prevalence of HPPR was 8.7%, 21.7%, and 50.0% in carriers of 0, 1, and 2 CYP2C19 variant alleles, respectively (p < 0.001). By multivariate analysis, carriage of CYP2C19 variant was a significant predictor of HPPR (odds ratio: 5.525, 95% confidence interval: 1.333 to 23.256, p = 0.018).ConclusionsAmong PCI-treated patients receiving high-MD clopidogrel, carriage of CYP2C19 variant relates to increased PR and predicts risk of HPPR. (Adjunctive Cilostazol Versus High Maintenance-dose ClopidogrEL in Acute Myocardial Infarction [AMI] Patients According to CYP2C19 Polymorphism [ACCELAMI2C19]; NCT00915733; and Comparison of Platelet Inhibition With Adjunctive Cilostazol Versus High Maintenance-Dose Clopidogrel According to Hepatic Cytochrome 2C19 Allele (CYP2C19) Polymorphism [ACCEL2C19]; NCT00891670)

    A Case of Spontaneous Coronary Artery Dissection Healed by Medical Treatment: Serial Findings of Coronary Angiography, Intravascular Ultrasound and Multi-Detector Computed Tomography

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    Spontaneous coronary artery dissection (SCAD) is an uncommon cause of acute coronary syndrome which may be related to lethal condition. Although several modalities including medical therapy have been suggested, agreement on optimal treatment has not yet been determined. We describe a case of SCAD which was presented as ST-segment elevation myocardial infarction, and treated successfully with medical treatment. Coronary angiography, intravascular ultrasound and multi-detector computed tomography showed the serial changes of this disease entity

    Reversible Lansoprazole-Induced Interstitial Lung Disease Showing Improvement after Drug Cessation

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    Lansoprazole is an acid proton-pump inhibiting drug that is used for the treatment of duodenal or gastric ulcers, H. pylori infection, gastroesophageal reflux disease or Zollinger-Ellison syndrome. Although lansoprazole is well known for its gastrointestinal and dermatologic adverse effects, mild pulmonary symptoms are also known to develop from taking this drug. There have been no reports about lansoprazole-induced interstitial lung disease. We report here a case of lansoprazole-induced interstitial lung disease that developed in a 66-year-old man
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