Genetic Toxicity Test of Nanosilica by Comet assay and Mouse Lymphoma Assay

Youn?Jung Kim(김연정),Han Seam Choi(최한샘),Dong Ge Ra Mi Moon(문동그라미),Ji Hee Kim(김지희),Hye Gyeong Jo(조혜경),Jae Chun Ryu(류재천) 환경독성보건학회 2007 한국독성학회 심포지움 및 학술발표회 Vol.- No.-

CPPU유도 참다래 단위결과 과실의 특성

조윤섭,조혜성,박문영,박재옥,박태동,김월수 全南大學校 農業科學技術硏究所 2001 農業科學技術硏究 Vol.36 No.-

This study was designed to find out an alternative to artificial pollination in kiwifruit production. The parthenocarpic kiwifruits induced by (N-2-chloro-4-pyridyl)-N-phenyl urea (CPPU) treatment tended to be less attractive due to deep furrowing and excessive outgrowth of stigma in mature fruits. Especially, on flower buds after CPPU spray, severe fruit-drop was induced. It was considered enough to spray CPPU at more than 4ppm to attain sufficient fruit set but needed to spray CPPU at more than 16ppm to attain marketable fruit size. When CPPU at 16ppm was sprayed to the same flower once, twice or three time, the fruits received CPPU treatment more time was larger but less attractive. Application of CPPU mare than at 16ppm seemed to be necessary to produce fruits heavier than 80 gr. Enlargement of the fruits received CPPU treatment mainly occurred cross wisely and vertical development was not affected and thickening of outer pericarp primarily contributed to the fruit enlargement. Difference in flesh color or contents of vitamin C and sugars between control fruits and CPPU-treated fruits was not noticed. In conclusion, CPPU treatment to induce parthenocarpic kiwifruits could be commercially applicable, only the method for improving fruit appearance is worked out.

Solvothermal Synthesis of α-Al₂O₃ from Boehmite with Seeding Technique

Jo, Hye Youn,Park, Min-Gyeong,Lee, Seung-Ho,Kim, Dae Sung,Lee, Young Kwan,Lim, Hyung Mi The Korean Ceramic Society 2015 한국세라믹학회지 Vol.52 No.4

${\alpha}-Al_2O_3$ was synthesized by solvothermal synthesis using ${\alpha}-Al_2O_3$ seed, precursor of fine boehmite (Al(OOH)) or gibbsite ($Al(OH)_3$), and 1, 4-butanediol solvent. The seed content and precursor type were selected as variables in order to synthesize ${\alpha}-Al_2O_3$. The formation time of ${\alpha}-Al_2O_3$ was reduced and the size of the particles was decreased with addition of the seed. When the seed content was increased, the size of the synthesized ${\alpha}-Al_2O_3$ was reduced. Morphologies of the as-synthesized ${\alpha}-Al_2O_3$ with ${\alpha}-Al_2O_3$ seed were polyhedron-shaped, while the shape was plate-like or polyhedral without the seed, depending on the additives or the average particle size of the boehmite precursor. The aggregation of as-synthesized ${\alpha}-Al_2O_3$ from boehmite was smaller than that from gibbsite. As-synthesized ${\alpha}-Al_2O_3$, with 140 nm size, was obtained by using the seed and boehmite precursor.

Effects of SiC Particle Size and Inorganic Binder on Heat Insulation of Fumed Silica-based Heat Insulation Plates

Jo, Hye Youn,Oh, Su Jung,Kim, Mi Na,Lim, Hyung Mi,Lee, Seung-Ho The Korean Ceramic Society 2016 한국세라믹학회지 Vol.53 No.4

Heat insulation plates of fumed silica were prepared by mixing fumed silica, SiC powder and chopped glass fiber by a high speed mixer followed by pressing of the mixture powder in a stainless steel mold of $100{\times}100mm$. Composition of the plates, particle size of SiC, and type of inorganic binder were varied for observation of their contribution to heat insulation of the plate. The plate was installed on the upper portion of an electric furnace the inside temperature of which was maintained at $400^{\circ}C$ and $600^{\circ}C$, for investigation of heat transfer through the plate from inside of the electric furnace to outside atmosphere. Surface temperatures were measured in real time using a thermographic camera. The particle size of SiC was varied in the range of $1.3{\sim}17.5{\mu}m$ and the insulation was found to be most excellent when SiC of $2.2{\mu}m$ was incorporated. When the size of SiC was smaller or larger than $2.2{\mu}m$, the heat insulation effect was decreased. Inorganic binders of alkali silicate and phosphate were tested and the phosphate was found to maintain the heat insulation property while increasing mechanical properties.

Successful Recovery of Bilateral Electric Cornea Burn

Youn hye Jo,Ki Cheul Shin 대한검안학회 2017 Annals of optometry and contact lens Vol.16 No.3

Purpose: To present a rare case of successful recovery from bilateral direct electric corneal injury and good long-term outcome in a 57-year-old healthy male. Case summary: The patient’s bilateral eyes encountered accidental exposure to electric spark while he was repairing high voltage live wire. He was not wearing a protective equipment at that moment. When he arrived at the emergency room, the best corrected visual acuity was finger count 50 cm in his right eye and 20/200 in his left eye. He complained of severe ocular pain and tearing. Although his both eyes showed severe corneal edema with central abrasion in his right eye on the day after the accident, these were healed rapidly and completely after medical treatment. After 10 days, his corneal edema and visual acuity were fully recovered and endothelial cells were intact. At 22 months after the injury, the patient had no complication. To the best of our knowledge, this is the first report of rapid and successful healing of bilateral corneal burn including endothelial cell state with a long term follow-up after direct electric ocular injury. Conclusion: Bilateral corneal electric burn patient can expect full recovery by timely management with good long-term outcome.

한국인에서 7년간의 안압 변화와 전

조윤혜(Youn hye Jo),지복준(Bokjun Ji),조병주(Byung Joo Cho) 대한안과학회 2017 대한안과학회지 Vol.58 No.9

Purpose: To investigate the changes in intraocular pressure (IOP) and associated systemic factors over 7 years in a healthy Korean population. Methods: This longitudinal study included healthy subjects with no history of ocular disease and who had been receiving health examinations seven years apart at the Konkuk University Medical Center, Healthcare Center. The participants completed lifestyle questionnaires and underwent general health examinations (blood pressure, height and weight, and blood biochemical tests) and ocular examinations including noncontact tonometry and fundus photography. Subjects with abnormal fundus photography findings and ocular hypertension were excluded. Changes in IOP and systemic factors over 7 years were analyzed. Results: Of 524 possible subjects, 469 were enrolled (55 subjects were excluded: 50 due to abnormal fundus photography and 5 for missing data). The left eye was analyzed in all patients. In all subjects, initial IOP (mean 14.50 ± 3.14 mmHg) was not significantly different from final IOP (14.72 ± 3.38 mmHg) (paired t-test, p = 0.074). In male patients, the final IOP was significantly higher than the initial IOP (paired t-test, p = 0.035). Lifestyle questionnaire variables were associated with a final IOP that was significantly higher than the initial IOP (smokers, alcohol drinkers and less exercisers, paired t-test; p = 0.014, 0.010 and 0.024, respectively). A linear mixed-effects model analysis showed that the change in IOP was negatively associated with age, but this was not statistically significant. Changes in systolic blood pressure (SBP), body mass index (BMI), total cholesterol (T.Chol) and low density lipoprotein (LDL) were positively correlated with change in IOP. Conclusions: A linear mixed-model analysis showed IOP decreased with age but this was not statistically significant. Changes in SBP, BMI, T.Chol and LDL were significantly positively correlated with change in IOP. J Korean Ophthalmol Soc 2017;58(9):1074-1079

Aberrant Promoter Hypomethylation of Sortilin 1: A Moyamoya Disease Biomarker

Sung, Hye Youn,Lee, Ji Yeoun,Park, Ae Kyung,Moon, Youn Joo,Jo, Inho,Park, Eun-Mi,Wang, Kyu-Chang,Phi, Ji Hoon,Ahn, Jung-Hyuck,Kim, Seung-Ki Korean Stroke Society 2018 Journal of stroke Vol.20 No.3

<P><B>Background and Purpose</B></P><P>The pathogenesis of moyamoya disease (MMD) remains poorly understood, and no reliable molecular biomarkers for MMD have been identified to date. The present study aimed to identify epigenetic biomarkers for use in the diagnosis of MMD. </P><P><B>Methods</B></P><P>We performed integrated analyses of gene expression profiles and DNA methylation profiles in endothelial colony forming cells (ECFCs) from three patients with MMD and two healthy individuals. Candidate gene mRNA expression and DNA methylation status were further validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and pyrosequencing analysis of an expanded ECFC sample set from nine patients with MMD and ten controls. We evaluated the diagnostic accuracy of the potential biomarkers identified here using receiver operating characteristic curve analyses and further measured major angiogenic factor expression levels using a tube formation assay and RT-qPCR. </P><P><B>Results</B></P><P>Five candidate genes were selected via integrated analysis; all five were upregulated by hypomethylation of specific promoter CpG sites. After further validation in an expanded sample set, we identified a candidate biomarker gene, sortilin 1 (<I>SORT1</I>). DNA methylation status at a specific <I>SORT1</I> promoter CpG site in ECFCs readily distinguished patients with MMD from the normal controls with high accuracy (area under the curve 0.98, sensitivity 83.33%, specificity 100%). Furthermore, <I>SORT1</I> overexpression suppressed endothelial cell tube formation and modulated major angiogenic factor and matrix metalloproteinase-9 expression, implying <I>SORT1</I> involvement in MMD pathogenesis. </P><P><B>Conclusions</B></P><P>Our findings suggest that DNA methylation status at the <I>SORT1</I> promoter CpG site may be a potential biomarker for MMD.</P>

Changes of Optical Coherence Tomography Parameters after Cataract Surgery in Primary Open-Angle Glaucoma Eyes

SoHyeon Kim(SoHyeon Kim),Youn Hye Jo(Youn Hye Jo) 대한안과학회 2023 Korean Journal of Ophthalmology Vol.37 No.1

Purpose: To investigate the impact of uncomplicated cataract surgery on the measurement of Bruch’s membrane opening- minimum rim width (BMO-MRW) and retinal nerve fiber layer thickness (RNFLT) using spectral domain optical coherence tomography (SD-OCT) in primary open-angle glaucoma (POAG) patients. Methods: This retrospective study included 63 eyes of 63 patients, including 32 POAG eyes and 31 normal eyes who underwent uneventful cataract surgery and follow-up for at least 6 months. Using SD-OCT, BMO-MRW and RNFLT were measured preoperatively and postoperatively at 6 months. Paired t-test was used to compare intraocular pressure (IOP), BMO-MRW, RNFLT, and image quality before and after surgery. These parameters and their changes were compared between POAG and normal groups. Univariate and multivariate linear regression analyses were performed to determine the factors associated with the postoperative change (Δ) in RNFLT and BMO-MRW. Results: BMO-MRW and RNFLT were significantly increased and IOP was decreased after phacoemulsification in both groups (p < 0.001, respectively). The ΔRNFLT was significantly greater in POAG eyes compared with the normal eyes (p < 0.001). The ΔRNFLT was associated with the postoperative IOP reduction and glaucoma diagnosis (p < 0.001 and p = 0.001, respectively). In the normal group, only the ΔIOP had a significant influence on the ΔRNFLT (p = 0.003), but in the POAG group, not only the ΔIOP (p = 0.044) but also preoperative visual field mean deviation (p = 0.029) showed a significant influence. The ΔBMO- MRW showed no difference between POAG and normal eyes. Conclusions: The postoperative increase of RNFLT was significantly greater in the POAG group, and the postoperative increase of RNFLT was associated with the preoperative visual field mean deviation and ΔIOP in POAG eyes and with the ΔIOP in normal eyes. Our results imply that RNFLT is more affected than BMO-MRW in POAG eyes compared to normal eyes by cataract surgery.

Assay of Cold Tolerance of Actinidia eriantha Benth

Youn-Seop Jo,Hye-Sung Cho,Jae-ok Park,Wol-Soo Kim 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Self Assembled Block Copolymer Gate Insulators with Cylindrical Nanostructures for Pentacene Thin Film Transistor

Jo, Pil-Sung,Park, Youn-Jung,Kang, Seok-Ju,Kim, Tae-Hee,Park, Cheol-Min,Kim, Eun-Hye,Ryu, Du-Yeol,Kim, Ho-Cheol 한국고분자학회 2010 Macromolecular Research Vol.18 No.8

This study examined the effect of a chemically nanostructured surface of cylinder forming poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and poly(styrene-b-4vinyl pyridine) (PS-b-P4VP) block copolymer gate dielectrics on the performance of the bottom gate pentacene organic thin film transistor (OTFT). The field effect mobility of pentacene is affected mainly by the chemical properties of the top skin of a block copolymer layer. In the case of PS-b-PMMA with cylindrical PMMA microdomains that are located very closely at the block copolymer-pentacene interface because the surface energy of PMMA is similar to that of PS, the field effect mobility in general corresponds to the area averaged value of the two mobilities with the pure PS and PMMA layer. On the other hand, PS-b-P4VP copolymer results in a similar field effect mobility to that of the pure PS layer because the cylindrical P4VP microdomains are embedded in the PS matrix of which the surface energy is much lower than that of P4VP. The orientation of the cylindrical PMMA microdomains with respect to the surface also affects the field effect mobility, where the PMMA microdomains are aligned perpendicular to the surface, gave rise to a mobility approximately 50% higher than those parallel to the surface. The composite model with parallel and series resistance units offers qualitative understanding of these results.