| 1. |
- Kim, Joon Tae, et al.
(författare)
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Dual antiplatelet Use for extended period taRgeted to AcuTe ischemic stroke with presumed atherosclerotic OrigiN (DURATION) trial : Rationale and design
- 2023
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Ingår i: International Journal of Stroke. - : SAGE Publications. - 1747-4930 .- 1747-4949. ; 18:8, s. 1015-1020
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: The optimal duration of dual antiplatelet therapy (DAPT) with clopidogrel-aspirin for the large artery atherosclerotic (LAA) stroke subtype has been debated. Aims: To determine whether the 1-year risk of recurrent vascular events could be reduced by a longer duration of DAPT in patients with the LAA stroke subtype. Methods and study design: A total of 4806 participants will be recruited to detect a statistically significant relative risk reduction of 22% with 80% power and a two-sided alpha error of 0.05, including a 10% loss to follow-up. This is a registry-based, multicenter, prospective, randomized, open-label, blinded end point study designed to evaluate the efficacy and safety of a 12-month duration of DAPT compared with a 3-month duration of DAPT in the LAA stroke subtype. Patients will be randomized (1:1) to either DAPT for 12 months or DAPT for 3 months, followed by monotherapy (either aspirin or clopidogrel) for the remaining 9 months. Study outcomes: The primary efficacy outcome of the study is a composite of stroke (ischemic or hemorrhagic), myocardial infarction, and all-cause mortality for 1 year after the index stroke. The secondary efficacy outcomes are (1) stroke, (2) ischemic stroke or transient ischemic attack, (3) hemorrhagic stroke, and (4) all-cause mortality. The primary safety outcome is major bleeding. Discussion: This study will help stroke physicians determine the appropriate duration of dual therapy with clopidogrel-aspirin for patients with the LAA stroke subtype. Trial registration: URL: https://cris.nih.go.kr/cris. CRIS Registration Number: KCT0004407.
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| 2. |
- Chen, Shula, et al.
(författare)
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On the origin of suppression of free exciton no-phonon emission in ZnO tetrapods
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 96:3, s. 033108-
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Tidskriftsartikel (refereegranskat)abstract
- Temperature dependent photoluminescence and cathodoluminescence (CL) spectroscopies are employed to investigate free exciton (FX) emissions in ZnO tetrapods. The intensity of the no-phonon line is found to be largely suppressed as compared with longitudinal optical phonon assisted transitions, in sharp contrast to bulk ZnO. From spatially resolved CL studies, this suppression is shown to strongly depend on structural morphology of the ZnO tetrapods and becomes most significant within areas with faceted surfaces. A model based on reabsorption due to multiple internal reflections in the vicinity of the FX resonance is suggested to account for the observed effect.
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| 3. |
- Lee, Sun-Kyun, et al.
(författare)
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Long lifetime of free excitons in ZnO tetrapod structures
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 96:8, s. 083104-
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Tidskriftsartikel (refereegranskat)abstract
- Time-resolved photoluminescence (PL) is employed to characterize optical quality of ZnO tetrapods. PL decay of free excitons (FE) is concluded to contain two components with time constants of 1 and 14 ns at room temperature. The fast PL decay is attributed to nonradiative recombination whereas the slow decay is suggested to mainly represent FE radiative lifetime, based on correlation between thermally induced increases in the PL linewidth and FE lifetimes. The results underline superior optical quality of the tetrapods as the decay time of the slow PL component is comparable to the longest lifetimes reported to date for ZnO.
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| 4. |
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| 5. |
- Koo, SM, et al.
(författare)
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Influence of trenching effect on the characteristics of buried-gate SiC junction field-effect transistors
- 2002
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Ingår i: Materials Science Forum, Vols. 389-393. ; , s. 1235-1238
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Konferensbidrag (refereegranskat)abstract
- Two different structures of junction field-effect transistors in 4H-SiC, with and without trenching effect in the channel region, have been fabricated and characterized. The devices formed with metal mask show a trenching profile (>similar to0.2 mum) after dry etch in the channel groove region and exhibited static induction transistor (SIT)-like characteristics in the sub-threshold region of I-V curves as the channel thickness decreases. The devices without trenching effect have been processed by using a wet-etched oxide mask resulting in a sloped dry-etch profile (theta=similar to30degrees) in the channel, and consequently showed well-saturated drain characteristics for all the channel thicknesses. The conduction mechanisms in these JFETs are examined by the potential profiles from two dimensional numerical simulations.
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| 6. |
- Lee, Sun Kyun, et al.
(författare)
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Cathodoluminescence characterization of ZnO tetrapod structures
- 2013
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Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 543, s. 114-117
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Tidskriftsartikel (refereegranskat)abstract
- Spatially resolved cathodoluminescence (CL) measurements are performed to characterize optical properties and structural quality of ZnO tetrapods. High optical quality of these structures is concluded based on the observation of intense free excitonic (FE) emission at room temperature and a low intensity of the so-called green emission of defect origin. CL mapping performed for individual tetrapods has revealed that the defects responsible for the green emission are predominantly located in core regions (i.e. close to leg junctions) and, therefore, are unlikely to reside near surfaces. Variations in the spectral positions of the FE emission monitored in tetrapod legs of different diameters are also observed and are attributed to the formation of whispering gallery mode polaritons within the tapered microcavity.
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| 7. |
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| 8. |
- Lee, Sun Kyun, et al.
(författare)
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Optical Characterizations of ZnO Tetrapod Nanostructures
- 2009
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Ingår i: Proc. of 33rd Workshop on Compound Semiconductor Devices and Integrated Circuits, Malaga, Spain, May 17-20 2009. ; , s. 4-7
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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