http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kim, Chinkyo,Yang, Min,Lee, Wonsang,Yi, Jaehyung,Kim, Sungwoo,Choi, Yoonho,Yoo, Tae-Kyung,Kim, Seon Tai 대전산업대학교 반도체기술연구소 2000 半導體技術硏究所報 Vol.2 No.-
Heteroepitaxial GaN film was grown on sapphire (0001) substrate by hydride vapor-phase epitaxy and it was observed employing scanning electron microscopy and cathodoluminescence that there were microstructural inhomogeneous areas showing suppressed luminescence characteristics compared with the surrounding matrix. They were presumed to be induced by polarity-inverted domains identified on the basis of the chemical inertness and heavily doped characteristics manifested in cathodoluminescence spectra.
Choi, Yoonho,Kang, Sehyeon,Cha, Song-Hyun,Kim, Hyun-Seok,Song, Kwangho,Lee, You Jeong,Kim, Kyeongsoon,Kim, Yeong Shik,Cho, Seonho,Park, Youmie Springer US 2018 NANOSCALE RESEARCH LETTERS Vol.13 No.1
<P>A green synthesis of gold and silver nanoparticles is described in the present report using platycodon saponins from Platycodi Radix (<I>Platycodon grandiflorum</I>) as reducing agents. Platycodin D (PD), a major triterpenoidal platycodon saponin, was enriched by an enzymatic transformation of an aqueous extract of Platycodi Radix. This PD-enriched fraction was utilized for processing reduction reactions of gold and silver salts to synthesize gold nanoparticles (PD-AuNPs) and silver nanoparticles (PD-AgNPs), respectively. No other chemicals were introduced during the reduction reactions, providing an entirely green, eco-friendly, and sustainable method. UV-visible spectra showed the surface plasmon resonance bands of PD-AuNPs at 536 nm and PD-AgNPs at 427 nm. Spherically shaped nanoparticles were observed from high-resolution transmission electron microscopy with average diameters of 14.94 ± 2.14 nm for PD-AuNPs and 18.40 ± 3.20 nm for PD-AgNPs. Minor triangular and other polygonal shapes were also observed for PD-AuNPs along with spherical ones. Atomic force microscopy (AFM) images also demonstrated that both nanoparticles were mostly spherical in shape. Curvature-dependent evolution was employed to enhance the AFM images and precisely measure the sizes of the nanoparticles. The sizes were measured as 19.14 nm for PD-AuNPs and 29.93 nm for PD-AgNPs from the enhanced AFM images. Face-centered cubic structures for both nanoparticles were confirmed by strong diffraction patterns from high-resolution X-ray diffraction analyses. Fourier transform infrared spectra revealed the contribution of –OH, aromatic C=C, C–O, and C–H functional groups to the synthesis. Furthermore, the catalytic activity of PD-AuNPs was assessed with a reduction reaction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. The catalytic activity results suggest the potential application of these gold nanoparticles as catalysts in the future. The green strategy reported in this study using saponins as reducing agents will pave new roads to develop novel nanomaterials with versatile applications.</P>
Staphylectomy using CO₂ laser for the treatment of nasopharyngeal stenosis in a cat
Ingeun Kim,Jong Baek Kim,Taewan Kim,Donghyeok Yoo,Eunchae Yoon,Daeun Kim,Ji Hyun Park,Yoonho Roh,Dongbin Lee 한국예방수의학회 2023 예방수의학회지 Vol.47 No.4
Nasopharyngeal stenosis is defined as a morphological transition of narrowing at the nasopharyngeal region. A 2-yearold, castrated male, Korean short hair cat was referred to the animal medical center, Gyeongsang National University. According to clinical signs, diagnostic imaging, and physical examination, nasopharyngeal stenosis was diagnosed. The staphylectomy was performed using a CO2 laser, and there were not any post-operative complications. The patient was discharged in two days. This report describes the case of nasopharyngeal stenosis in cat and represents that laser ablation could be a good option for surgical management of the nasopharyngeal region with a low complication rate.
Effect of Aging on Speech Discrimination
Choi Jiwon,Kim Taeho,Kim Sunhong,Kim Yoonho,Kim Dong-Kee 대한청각학회 2022 Journal of Audiology & Otology Vol.26 No.4
Background and Objectives: The aim of this study was to investigate the factors associated with decrease in speech discrimination ability seen in patients with presbycusis and whether aging has a significant effect on the observed decline.Subjects and Methods: We retrospectively analyzed the medical records of patients aged >40 years who had undergone pure-tone audiometry, speech audiometry, and auditory brainstem response for hearing loss at our hospital from January 2019 to June 2021, and investigated the factors that correlated with speech discrimination score.Results: We enrolled 103 patients with 120 ears, with a mean age of 65.8±11.9 years. The pure-tone average of the patients’ thresholds at 0.5, 1, 2, and 4 kHz was 37.2±27.7 dB HL, and their mean speech discrimination score was 82.5%± 22.3%. A correlation analysis revealed a significant negative correlation between the patients’ speech discrimination scores and age. In addition, all variables of pure-tone audiometry and the patients’ auditory brainstem responses were significantly correlated with the speech discrimination scores. The pure-tone average had the strongest negative correlation. On analyzing the significant predictors of lower speech discrimination scores, using a multiple linear regression analysis, pure-tone average and age showed significant results.Conclusions: The speech discrimination ability of older patients with hearing loss significantly decreases with increasing pure-tone average and age.