Li intercalation is commonly used to enhance the carrier density in epitaxial graphene and mitigate coupling to the substrate. So far, the understanding of the intercalation process, particularly how Li penetrates different layers above the substrate, and its impact on electron transport remains incomplete. Here, we report different phases of Li intercalation and their kinetic processes in epitaxial mono- and bilayer graphene grown on SiC.
View Article and Find Full Text PDFUnconventional blue thermally activated delayed fluorescent emitters having electron-donating type indolocarbazole as an acceptor were developed by attaching carbazolylcarbazole or acridine donors to the indolocarbazole acceptor. Three compounds were derived from the indolocarbazole acceptor. The indolocarbazole-acridine combined products showed efficient delayed fluorescent behavior and a high quantum efficiency of 19.
View Article and Find Full Text PDFA new donor moiety, 7,7,13,13-tetramethyl-7,13-dihydro-5H-indeno[1,2-b]acridine (IAc), was developed to control the highest occupied molecular orbital (HOMO) dispersion of thermally activated delayed fluorescent (TADF) emitters. The IAc unit expanded the HOMO dispersion of the emitters and increased the quantum efficiency of the TADF devices up to 20.9 %.
View Article and Find Full Text PDFTwo host materials, 9-(3''-(9H-carbazol-9-yl)-[1,1':2',1''-terphenyl]-3-yl)-α-carboline (CzOTCb) and 3,3''-bis(α-carbolin-9-yl)-1,1':2',1''-terphenyl (CbOTCb), derived from carboline and ortho-linked terphenyl were synthesized as high triplet energy materials and showed a high triplet energy of 2.90 eV. CzOTCb and CbOTCb were evaluated as the host materials for blue phosphorescent organic light-emitting diodes and high quantum efficiencies of 27.
View Article and Find Full Text PDFBackground/aims: The standard treatment for chronic hepatitis C infected with hepatitis C virus (HCV) genotype 1 is a combination of pegylated interferon alfa and ribavirin over a 48 weeks period. It is unclear if 24 weeks treatment is possible for patients showing a rapid virological response (RVR) without compromising the sustained virological response (SVR) in Korea.
Methods: Between June 2005 and September 2008, among patients chronically infected with the HCV genotype 1 who were treated with pegylated interferon alfa subcutaneously once weekly plus ribavirin based on body weight, 55 patients who had low pretreatment viral load (<600,000 IU/mL) and RVR were enrolled.
Korean J Gastroenterol
September 2009
Primary non-Hodgkin's lymphoma of the extrahepatic bile duct presenting as obstructive jaundice is extremely rare. A 60-year-old man was admitted due to suddenly developed jaundice. Computerized tomography and endoscopic retrograde cholangiopancreatography showed a tumor at the proximal common hepatic duct.
View Article and Find Full Text PDFCowden's disease, also known as various hamartomatous malformations of multiple organs, is a rare autosomal dominant disorder. The most important feature of Cowden's disease is its frequent association with malignant neoplasm, particularly in the breast and thyroid gland. Cowden's disease with malignant neoplasms is quite rare in Korea so far.
View Article and Find Full Text PDFKorean J Gastroenterol
September 2007
Generally, colon lipoma is mildly symptomatic or asymptomatic. However, sometimes it may present with symptoms, such as pain, constipation, obstruction, or bleeding and may be the leading point for intussusception, particularly in large size (>20 mm). Giant colon lipoma may warrant the removal to exclude confusion with other lesions that have a malignant potential and to control symptoms.
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