http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
OGLE-2017-BLG-1049: ANOTHER GIANT PLANET MICROLENSING EVENT
Kim, Yun Hak,Chung, Sun-Ju,Udalski, A.,Bond, Ian A.,Jung, Youn Kil,Gould, Andrew,Albrow, Michael D.,Han, Cheongho,Hwang, Kyu-Ha,Ryu, Yoon-Hyun,Shin, In-Gu,Shvartzvald, Yossi,Yee, Jennifer C.,Zang, Wei The Korean Astronomical Society 2020 Journal of The Korean Astronomical Society Vol.53 No.6
We report the discovery of a giant exoplanet in the microlensing event OGLE-2017-BLG-1049, with a planet-host star mass ratio of q = 9.53 ± 0.39 × 10-3 and a caustic crossing feature in Korea Microlensing Telescope Network (KMTNet) observations. The caustic crossing feature yields an angular Einstein radius of θE = 0.52 ± 0.11 mas. However, the microlens parallax is not measured because the time scale of the event, tE ≃ 29 days, is too short. Thus, we perform a Bayesian analysis to estimate physical quantities of the lens system. We find that the lens system has a star with mass Mh = 0.55+0.36-0.29 M⊙ hosting a giant planet with Mp = 5.53+3.62-2.87 MJup, at a distance of DL = 5.67+1.11-1.52 kpc. The projected star-planet separation is a⊥ = 3.92+1.10-1.32 au. This means that the planet is located beyond the snow line of the host. The relative lens-source proper motion is μrel ~ 7 mas yr-1, thus the lens and source will be separated from each other within 10 years. After this, it will be possible to measure the flux of the host star with 30 meter class telescopes and to determine its mass.
Mahmood, A.,Park, S.D.,Jun, B.H.,Youn, J.S.,Han, Y.H.,Sung, T.H.,Kim, C.J. North-Holland 2009 Physica. C, Superconductivity Vol.469 No.15
Single grain YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-x</SUB> (Y123) bulk superconductors with Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211) and various amounts of BaCeO<SUB>3</SUB> (5-45wt.% by an increment of 10wt.%) were fabricated by a seeded infiltration process. The addition of BaCeO<SUB>3</SUB> was found to be effective for a modification of the microstructure and an improvement of the superconducting properties. The refinement effect for Y211 particles within an entire superconducting YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-x</SUB> (Y123) matrix was achieved by BaCeO<SUB>3</SUB> additions. The critical current density (J<SUB>c</SUB>) values were increased as the BaCeO<SUB>3</SUB> contents were increased (maximum J<SUB>c</SUB> at 35wt.% BaCeO<SUB>3</SUB> addition). The J<SUB>c</SUB> improvement by BaCeO<SUB>3</SUB> additions might be due to the microstructure modifications associated with the finely distributed Y211 and BaCeO<SUB>3</SUB> particles. With the addition of BaCeO<SUB>3</SUB> the onset T<SUB>c</SUB> values decreased slightly, indicating highly limited Ce substitution for Y site. It can be concluded that the BaCeO<SUB>3</SUB> addition has a beneficial effect on the morphology, the size and the distribution of the Y211 inclusions and the microstructure regarding pinning improvement.
Single-shot dual-energy x-ray imaging with a flat-panel sandwich detector for preclinical imaging
Han, J.C.,Kim, H.K.,Kim, D.W.,Yun, S.,Youn, H.,Kam, S.,Tanguay, J.,Cunningham, I.A. Elsevier 2014 Current Applied Physics Vol.14 No.12
We describe a multi-layer (''sandwich'') configuration detector consisting of two x-ray imaging flat-panel detectors for single-shot (single-kV) dual-energy imaging. An intermediate copper filter is used to increase spectral separation between the two detectors to improve contrast at the expense of image noise. Monte Carlo and cascaded-systems analyses of the signal and noise performance are described that quantify performance characteristics. Image quality of dual-energy images obtained from a prototype sandwich-detector system is evaluated using a figure of merit (FOM), defined as the squared contrast-to-noise ratio normalized by x-ray exposure for a mouse phantom for preclinical imaging. Demonstration dual-energy bone and soft-tissues images of a postmortem mouse are obtained using the prototype system. While the FOM with the single-shot detector is lower than that achieved using a conventional dual-shot (dual-kV) method, the single-shot approach may be preferable when imaging speed or insensitivity to motion artifacts is a primary concern.
Jin, C.H.,Chae, S.Y.,Son, S.,Kim, T.H.,Um, K.A.,Youn, Y.S.,Lee, S.,Lee, K.C. Elsevier Science Publishers 2009 Journal of controlled release Vol.133 No.3
An orally active glucagon-like peptide-1 (GLP-1) formulation would have great advantages over conventional injectable therapies for the treatment of diabetic patients. Because GLP-1 absorption in the intestine is restricted by its natural physiological characteristics, biotinylated exendin-4 analogues might useful as orally active GLP-1 receptor agonists. Three different biotinylated exendin-4 analogues, Lys<SUP>27</SUP>-Biotin-Exendin-4 (MB1-Ex-4), Lys<SUP>12</SUP>-Biotin-Exendin-4 (MB2-Ex-4), and Lys<SUP>12, 27</SUP>-Biotin-Exendin-4 (DB-Ex-4) were prepared, and their biological activities and enzymatic stabilities were studied in vitro. The hypoglycemic effects and pharmacokinetics of these analogues after oral administration were evaluated in db/db mice and Sprague-Dawley rats, respectively. These biotinylated exendin-4 analogues preserved GLP-1 receptor binding affinity and stimulated insulin secretion in RIN-m5F murine insulinoma cells and in isolated rat islets, respectively, and were as potent as exendin-4. In particular, DB-Ex-4 showed 9.0-fold better stability against rat intestinal fluid than exendin-4. When 0.1, 1, and 10 μg/mouse of DB-Ex-4 were orally administered, mean total hypoglycemic degrees (HGD) were increased by 36.8+/-1.2, 46.9+/-1.8, and 54.3+/-4.5%, respectively, whereas 1 μg/mouse of native exendin-4 showed an increase of 8.8+/-7.3%. This study demonstrates that biotinylated exendin-4 analogues are absorbed in the intestine and that they have biological efficacies of exendin-4. Furthermore, it indicates that biotinylated exendin-4 analogues could be used as potential oral antidiabetic agent for the treatment of type 2 diabetes.
Youn, J.S.,No, K.,Kim, Y.H.,Mahmood, A.,Jun, B.H.,Han, Y.H.,Sung, T.H.,Kim, C.J. North-Holland 2009 Physica. C, Superconductivity Vol.469 No.15
To understand the effect of BaCeO<SUB>3</SUB> on a Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211) distribution, Y<SUB>1.5</SUB>Ba<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>x</SUB> (Y1.5) superconductors with/without 1wt.% BaCeO<SUB>3</SUB> additions were prepared by a top-seeded melt-textured growth (TSMG) process. Two different BaCeO<SUB>3</SUB> powders (as-synthesized (coarse powder) and an attrition-milled (fine powder)) were used and the size effect was compared with that obtained from a Y1.5 sample with no addition. A refinement of the Y211 particles was achieved for both the as-synthesized and attrition-milled BaCeO<SUB>3</SUB> additions. The distribution of the Y211 particles was most uniform in the Y1.5 sample prepared with the attrition-milled BaCeO<SUB>3</SUB> powder due to the reduced size of the Y211-free regions by the fine size BaCeO<SUB>3</SUB> addition. The highest J<SUB>c</SUB> was achieved in the Y1.5 sample prepared with the attrition-milled BaCeO<SUB>3</SUB> powder. The J<SUB>c</SUB> result agreed well with the microstructure variations by the addition of BaCeO<SUB>3</SUB> powders.
Lee, Sang A,Oh, Seokjae,Hwang, Jae-Yeol,Choi, Minseok,Youn, Chulmin,Kim, Ji Woong,Chang, Seo Hyoung,Woo, Sungmin,Bae, Jong-Seong,Park, Sungkyun,Kim, Young-Min,Lee, Suyoun,Choi, Taekjib,Kim, Sung Wng,C The Royal Society of Chemistry 2017 ENERGY AND ENVIRONMENTAL SCIENCE Vol.10 No.4
<P>Transition metal oxides have been extensively studied and utilized as efficient catalysts. However, the strongly correlated behavior which often results in intriguing emergent phenomena in these materials has been mostly overlooked in understanding the electrochemical activities. Here, we demonstrate a close correlation between the phase transitions and oxygen evolution reaction (OER) in strongly correlated SrRuO3. By systematically introducing Ru-O vacancies into the single-crystalline SrRuO3epitaxial thin films, we induced a phase transition in crystalline symmetry which resulted in the corresponding modification of the electronic structure. The modified electronic structure significantly affects the electrochemical activities, so a 30% decrease in the overpotential for the OER activity was achieved. Our study suggests that a substantial enhancement in the OER activity can be realized even within single material systems, by rational design and engineering of their crystal and electronic structures.</P>
Kim Yeon Soo,Lee Su Hyun,Kim Soo-Yeon,Kim Eun Sil,Park Ah Reum,Chang Jung Min,Park Vivian Youngjean,Yoon Jung Hyun,Kang Bong Joo,Yun Bo La,Kim Tae Hee,Ko Eun Sook,Chu A Jung,Kim Jin You,Youn Inyoung,C 대한영상의학회 2024 Korean Journal of Radiology Vol.25 No.1
Objective: To investigate whether reader training improves the performance and agreement of radiologists in interpreting unenhanced breast magnetic resonance imaging (MRI) scans using diffusion-weighted imaging (DWI). Materials and Methods: A study of 96 breasts (35 cancers, 24 benign, and 37 negative) in 48 asymptomatic women was performed between June 2019 and October 2020. High-resolution DWI with b-values of 0, 800, and 1200 sec/mm2 was performed using a 3.0-T system. Sixteen breast radiologists independently reviewed the DWI, apparent diffusion coefficient maps, and T1-weighted MRI scans and recorded the Breast Imaging Reporting and Data System (BI-RADS) category for each breast. After a 2-h training session and a 5-month washout period, they re-evaluated the BI-RADS categories. A BI-RADS category of 4 (lesions with at least two suspicious criteria) or 5 (more than two suspicious criteria) was considered positive. The per-breast diagnostic performance of each reader was compared between the first and second reviews. Inter-reader agreement was evaluated using a multi-rater κ analysis and intraclass correlation coefficient (ICC). Results: Before training, the mean sensitivity, specificity, and accuracy of the 16 readers were 70.7% (95% confidence interval [CI]: 59.4–79.9), 90.8% (95% CI: 85.6–94.2), and 83.5% (95% CI: 78.6–87.4), respectively. After training, significant improvements in specificity (95.2%; 95% CI: 90.8–97.5; P = 0.001) and accuracy (85.9%; 95% CI: 80.9–89.8; P = 0.01) were observed, but no difference in sensitivity (69.8%; 95% CI: 58.1–79.4; P = 0.58) was observed. Regarding inter-diffusionreader agreement, the κ values were 0.57 (95% CI: 0.52–0.63) before training and 0.68 (95% CI: 0.62–0.74) after training, with a difference of 0.11 (95% CI: 0.02–0.18; P = 0.01). The ICC was 0.73 (95% CI: 0.69–0.74) before training and 0.79 (95% CI: 0.76–0.80) after training (P = 0.002). Conclusion: Brief reader training improved the performance and agreement of interpretations by breast radiologists using unenhanced MRI with DWI.