Background/AimsWestern surveillance strategies cannot be directly adapted to the Korean population. The aim of this study was to estimate the risk of metachronous neoplasia and the optimal surveillance interval in the Korean population.MethodsClinical and pathological data from index colonoscopy performed between June 2006 and July 2008 and who had surveillance colonoscopies up to May 2015 were compared between low- and high-risk adenoma (LRA and HRA) groups. The 3- and 5-year cumulative risk of metachronous colorectal neoplasia in both groups were compared.ResultsAmong 895 eligible patients, surveillance colonoscopy was performed in 399 (44.6%). Most (83.3%) patients with LRA had a surveillance colonoscopy within 5 years and 70.2% of patients with HRA had a surveillance colonoscopy within 3 years. The cumulative risk of metachronous advanced adenoma was 3.2% within 5 years in the LRA group and only 1.7% within 3 years in the HRA group. The risk of metachronous neoplasia was similar between the surveillance interval of <5 and ≥5 years in the LRA group; however, it was slightly higher at surveillance interval of ≥3 than <3 years in the HRA group (9.4% vs. 2.4%). In multivariate analysis, age and the ≥3-year surveillance interval were significant independent risk factors for metachronous advanced adenoma (P=0.024 and P=0.030, respectively).ConclusionsPatients had a surveillance colonoscopy before the recommended guidelines despite a low risk of metachronous neoplasia. However, the risk of metachronous advanced adenoma was increased in elderly patients and those with a ≥3-year surveillance interval.
We investigated the structural and optical properties of In-Si-O thin films as the phase abruptly changes from nanocrystalline (nc) to amorphous (a) with increasing Si content. In-Si-O thin films were deposited on Si substrate using a co-sputtering deposition method. The RF power of the In2O3 target was fixed at 100 W, while the power applied to the SiO2 target was varied between 0 W and 60 W. At the Si = 2.8 at. %, i.e., at the onset of amorphous phase, the optical properties, including the dielectric functions, optical gap energies, and phonon modes, changed abruptly which were triggered by changes in the crystallinity and surface morphology. X-ray diffraction (XRD) spectra showed crystalline (c-) In2O3-like peaks below Si = 2.2%. Additionally, a broad peak associated with an amorphous (a-) In2O3 phase appeared above 2.8%. However, the Raman spectra of In-Si-O showed very weak peaks associated with c-In2O3 below 2.2%, and then showed a strong Raman peak associated with a-In-Si-O above 2.8%. X-ray photoelectron spectroscopy measurements showed that oxygen vacancy-related peak intensities increased abruptly above Si = 2.8%. The contrasting results of XRD and Raman measurements can be explained as follows: first, the large enhancement in Drude tails in the a-In-Si-O phase was caused by Si-induced amorphization and a large increase in the density of oxygen vacancies in the In-Si-O thin films. Second, the apparently drastic increase of the Raman peak intensity near 364 cm−1 (for amorphous phase, i.e., above Si = 2.8%) is attributed to a disorder-activated infrared mode caused by both the amorphization and the increase in the oxygen vacancy density in In-Si-O thin films.
The authors investigated the characteristics of Nb-doped In2O3 (INbO) films prepared by co-sputtering of Nb2O5 and In2O3 for use in transparent anodes for organic solar cells (OSCs). To optimize the Nb dopant composition in the In2O3 matrix, the effect of the Nb doping power on the resistivity and transparency of the INbO films were examined. The electronic structure and microstructure of the INbO films were also investigated using synchrotron x-ray absorption spectroscopy and x-ray diffraction examinations in detail. At the optimized Nb co-sputtering power of 30 W, the INbO film exhibited a sheet resistance of 15 Ω/sq, and an optical transmittance of 86.04% at 550 nm, which are highly acceptable for the use as transparent electrodes in the fabrication of OSCs. More importantly, the comparable power conversion efficiency (3.34%) of the OSC with an INbO anode with that (3.31%) of an OSC with a commercial ITO anode indicates that INbO films are promising as a transparent electrode for high performance OSCs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.