In recent years when the demand for high-performance biosensors has been aroused, a field-effect transistor (FET)-type biosensor (BioFET) has attracted great interest because of its high sensitivity, label-free detection, fast detection speed, and miniaturization. However, the insulating membrane in the conventional BioFET, which is essential in preventing the surface dangling bonds of typical semiconductors from nonspecific bindings, has limited the sensitivity of biosensors. Here, we present a highly sensitive and reusable membraneless BioFET based on a defect-free van der Waals material, tungsten diselenide (WSe).
View Article and Find Full Text PDFSingle-junction p–i–n InGaP solar cells are grown at various temperatures from 620 to 700 °C by low pressure metalorganic chemical vapor deposition on GaAs (001) substrates. The short circuit current density of the p–i–n InGaP solar cells increases by up to 38.8% when the growth temperature is reduced from 700 to 620 °C, while the open circuit voltage and fill factor show relatively small changes.
View Article and Find Full Text PDFBackground: Nonalcoholic fatty liver disease, the hepatic manifestation of metabolic syndrome, is associated with increased risk of colorectal adenoma, a precursor of colorectal cancer. Because nonalcoholic fatty liver disease and colorectal adenoma share many common risk factors of metabolic syndrome, the association between these 2 pathological findings has been investigated in multiple studies, but the results have been conflicting.
Objective: The present study aimed to assess the relationship between the fatty liver index, a predictor of nonalcoholic fatty liver disease, and the prevalence of colorectal adenomas.
GaAs solar cells with nanostructured emitter layers were fabricated via metal-assisted chemical etching. Au nanoparticles produced via thermal treatment of Au thin films were used as etch catalysts to texture an emitter surface with nanohole structures. Epi-wafers with emitter layers 0.
View Article and Find Full Text PDFRadical gastrectomy followed by adjuvant chemotherapy for advanced gastric cancer causes serious nutritional impairment. Our study evaluated the clinical impact of body mass index (BMI) on the long-term outcomes of advanced gastric cancer (stage II and III). We analyzed 211 cases of stage II and III gastric cancer between January 2005 and December 2010 at Chung-Ang University Hospital, Seoul, Korea.
View Article and Find Full Text PDFIn this study, we report experimental results on the epitaxial growth of InP layer on GaAs (001) substrate by using MOCVD. We have systematically controlled nucleation steps in order to obtain InP epitaxial layers with high crystallinity quality. The controlling parameters were flow ratio of V/IIIsources and thicknesses of nucleation layer for nucleation steps.
View Article and Find Full Text PDFIn this paper, we describe a design, simulation, and fabrication of an InGaAs/InP single photon avalanche photodiode (SPAD), which requires a much higher gain, compared to APD's for conventional optical communications. To achieve a higher gain, an efficient multiplication width control is essential because it significantly affects the overall performance including not only gain but also noise characteristics. Normally, the multiplication layer width is controlled by the Zinc diffusion process.
View Article and Find Full Text PDFWe report the efficiency enhancement of III-V InGaP/GaAs/ Ge triple-junction (TJ) solar cells using a novel structure, i.e., vertically-oriented gallium oxide hydroxide (GaOOH) nanopillars (NPs), as an antireflection coating.
View Article and Find Full Text PDFWe report the efficiency enhancement of III-V InGaP/GaAs/ Ge triple-junction (TJ) solar cells using a novel structure, i.e., vertically-oriented gallium oxide hydroxide (GaOOH) nanopillars (NPs), as an antireflection coating.
View Article and Find Full Text PDFWe demonstrated the efficiency improvement of GaAs single-junction (SJ) solar cells with the single-material zinc sulfide (ZnS) bi-layer based on the porous/dense film structure, which was fabricated by the glancing angle deposition (GLAD) method, as an antireflection (AR) coating layer. The porous ZnS film with a low refractive index was formed at a high incident vapor flux angle of 80° in the GLAD. Each optimum thickness of ZnS bi-layer was determined by achieving the lowest solar weighted reflectance (SWR) using a rigorous coupled-wave analysis method in the wavelength region of 350-900 nm, extracting the thicknesses of 20 and 50 nm for dense and porous films, respectively.
View Article and Find Full Text PDFBackground: Coronary angiography (CAG) is an invasive diagnostic procedure, which could lead to procedure related complications. One of the well known post-procedural complications is cerebral embolic infarction with or without symptoms. Silent embolic cerebral infarction (SECI) has clinical significance because it can progress to a decline in cognitive function and increase the risk of dementia in the long term.
View Article and Find Full Text PDFBackground: The ratio of peak early diastolic mitral inflow to annular velocity (E/E') and left atrial size could provide prognosis on congestive heart failure (CHF). N-terminal Pro B-type natriuretic peptide (NT-ProBNP) has also been useful for predicting adverse cardiac events. However, it is not clear how these parameters compare with conventional risk factors.
View Article and Find Full Text PDFA 79-year-old man was followed in our hospital for 4 years following primary percutaneous coronary intervention at another hospital to deploy two stents at the left anterior descending coronary artery for acute myocardial infarction (AMI). At the first visit in our hospital, echocardiography revealed a small ventricular septal defect (VSD, 0.8 to 1.
View Article and Find Full Text PDFRecently, the number of patients in whom a drug-eluting stent (DES) has recently been implanted and who need to undergo surgery or the most invasive procedure is increasing. However, there are limited data about the risk of perioperative thrombosis of DES. We evaluated the incidence and the risk factors of DES thrombosis during the perioperative period.
View Article and Find Full Text PDFWe report a case of infective endocarditis of the mitral valve, which was accompanied by pulmonary emboli traveling through an atrial septal defect. An 18-year-old male was admitted to our hospital due to a fever, polyarthritis and subcutaneous hemorrhage. Transthoracic echocardiography revealed a mobile mass and possible vegetation lodged in the mitral valve and a secundum-type atrial septal defect.
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