Skin entrance dose for digital and film radiography in Korean dental schools

Cho, Eun-Sang,Choi, Kun-Ho,Kim, Min-Gyu,Lim, Hoi-Jeong,Yoon, Suk-Ja,,Kang, Byung-Cheol 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.4

Purpose : This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Materials and Methods : Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician (s) at each school to set the exposure parameters and aiming the x-ray tube for the periapical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter : Unfors instruments, Billdal, Sweden). Results : The median dose was 491.2 μGy for digital radiography and 1,205.0 μGy for film radiography. The skin entrance dose digital radiography was significantly lower than that of film radiography (p<0.05). Conclusion : Fifty-nine percent skin entrance dose reduction with digital periapical radiography was achieved over the film radiography in Korean dental schools.

Metal stain on monolithic zirconia restoration: A case report

Min-Sang Cha,Sang-Woon Lee,Yoon-Hyuk Huh2,Lee-Ra Cho2,Chan-Jin Park 대한치과보철학회 2017 The Journal of Advanced Prosthodontics Vol.9 No.2

In restorative treatment using fixed dental prostheses, dentists should select appropriate restoration material among various types of dental materials. The strength, marginal fit, esthetics, wear resistance, biocompatibility, and cost are important factors in the choice of restoration materials. The present case showed a surface stain on a monolithic zirconia restoration that was due to wear between the monolithic zirconia restoration and the base metal alloy restoration. This phenomenon was confirmed by surface roughness measurement and electron probe micro-analysis.

시간의 흐름에 따른 핸드폰의 품질동태성에 관한 연구

윤성필(Sung-Pil Yoon),임성욱(Sung-Uk Lim),박만희(Man-Hee Park),조인희(In-Hee Cho) 한국엔터테인먼트산업학회 2010 한국엔터테인먼트산업학회논문지 Vol.4 No.3

본 연구는 선행연구에서 조사된 핸드폰의 고객요구속성을 Kano 모델의 품질특성에 적용하여 시간의 흐름에 따라 어떤 변화가 있는지를 살펴보고자 한다. 또한 고객들의 새로운 요구속성이 나타났는지도 함께 살펴보고자 한다. 많은 문헌과 선행연구에서 나타나고 있는 시간에 따른 품질특성의 이동이 매력적 품질에서 일원적 품질로 일원적 품질에서 당연적 품질로 변화하는 진부화(陳腐化)현상이 나타나는지도 함께 살펴보고자 한다. In this study, previous research (Sung-Uk Lim, 2004) surveyed in customer demand for mobile phones the quality characteristics of properties applied to the Kano model, the flow of time, depending on whether any changes will be discussed. In addition, our customers" new requirements will be examined along with the property map appeared. The movement of time-dependent quality characteristics appeared in many previous studies Obsolescence Phenomenon - from Attactive Quality Element to One-Dimensional Quality Element, from One-Dimensional Quality Element to Must-Be Quality Element - may appear be examined together.

제주 성상 S/S MTr #1 행원 풍력단지 전압해석

김상준(Sang-Jun Kim),조민호(Min-Ho Cho),윤기갑(Gi-Gab Yoon),장상옥(Sang-Ok Jang),안정식(Jeong-Shik Ahn) 대한전기학회 2003 대한전기학회 학술대회 논문집 Vol.2003 No.11

Efficient Interleukin-21 Production by Optimization of Codon and Signal Peptide in Chinese Hamster Ovarian Cells

( Hee Jun Cho ),( Byung Moo Oh ),( Jong-tae Kim ),( Jeewon Lim ),( Sang Yoon Park ),( Yo Sep Hwang ),( Kyoung Eun Baek ),( Bo-yeon Kim ),( Inpyo Choi ),( Hee Gu Lee ) 한국미생물 · 생명공학회 2019 Journal of microbiology and biotechnology Vol.29 No.2

Interleukin-21 is a common γ-chain cytokine that controls the immune responses of B cells, T cells, and natural killer cells. Targeting IL-21 to strengthen the immune system is promising for the development of vaccines as well as anti-infection and anti-tumor therapies. However, the practical application of IL-21 is limited by the high production cost. In this study, we improved IL-21 production by codon optimization and selection of appropriate signal peptide in CHO-K1 cells. Codon-optimized or non-optimized human IL-21 was stably transfected into CHO-K1 cells. IL-21 expression was 10-fold higher for codon-optimized than non-optimized IL-21. We fused five different signal peptides to codon-optimized mature IL-21 and evaluated their effect on IL-21 production. The best result (a 3-fold increase) was obtained using a signal peptide derived from human azurocidin. Furthermore, codon-optimized IL-21 containing the azurocidin signal peptide promoted IFN-γ secretion and STAT3 phosphorylation in NK-92 cells similar to codon-optimized IL-21 containing original signal peptide. Collectively, these results indicate that codon optimization and azurocidin signal peptides provide an efficient approach for the high-level production of IL-21 as a biopharmaceutical.

C3H 생쥐에서 자외선 B의 집중조사와 분할조사가 표피내 랑게르한스 세포의 회복에 미치는 영향

구상완,한승경,박윤기,조무연 ( Sang Wahn Koo,Seung Kyung Hann,Yoon Kee Park,Moo Yon Cho ) 대한피부과학회 1991 대한피부과학회지 Vol.29 No.4

N/A The Effect on the Recovery of Epidermal Langerhans Cells in C3H Mice after Single and Fractionated Exposure of Ultraviolet B Irradiation Sang-Wahn Koo, M.D., Seung Kyung Hann, M.D., Yoon-Kee Park, M.D., Moo Yon Cho, M.D. Department of Dermatology, Yonsei University College of Medicine Seoul, Korea The study was undertaken to see the recovery in epidermal Langerhans cells in relation to time after UVB irradiation through different amounts and ways of exposure in C3H mice. We irradiated the ears of C3H mice with UVB 200mJ/㎤ and 400mJ/㎤ in a single dose at one time and 5 fractionated doses for 5 days and 10 fractionated doses for 10 days and performed biopsies on the ears of the control and experimental groups after, 2, 7, 14, 21 days of irradiation and stained them by the immunoperoxidase method. The results are summarized as follows. 1. A more significant decrease in the number of Ia-positive epidermal Langerhans cells was observed in single-dose-exposed group than fractionated-dose-exposed groups on the second day of irradiation. 2. On the seventh day of exposure, the number of the Ia-positive epidermal cells in single-dose-exposed group returned to normal, but in fractionated-dose-exposed groups the number of Langerhans cells decreased most remarkably. 3. In fractionated-dose-exposed groups, the number of Langerhans cells returned to normal on the 14th or 21st day of expposure. (Kor J Dermatol 29(4) : 459-465, 1991)

수종의 광독성 약물투여 후 시간에 따른 피부농도 및 최소 광독량에 관한 연구

박윤기,조무연,한승경,임성빈 ( Yoon Kee Park,Moo Yon Cho,Seung Kyung Hann,Sung Bin Im ) 대한피부과학회 1991 大韓皮膚科學會誌 Vol.29 No.5

N/A The Skin Concentration and Minimal Phototoxic Dose Following Administration of Phototoxic Drugs as a Function of Time Yoon-Kee Park, M.D., Moo Yon Cho, M.D., Saung Kyung Hann, M.D., Sungbin im, M.D. Department of Dermatology Yonsei Univeraity College of Medicine, Seoul, Korea Psoralen photochemotherapy(PUVA) is defined as a treatment that depends on the interaction of a photosensitizing substance, psoralen, and long wave jltraviolet(UVA) radiation that results in therapeutically beneficial effects. The rationale of its use is to clear skin disease by repeated controlled phototoxic reactions. The efficacy of PUVA depends on the drug, the UVA dose and wave length, the individual sensitivity to the phototoxic reaction and on the disease to be treated. However, the major factor is the amount of psoralen at the site of photochemical reaction in skin. Daspite the extensive experiences which have now accumulated in the use of PUVA, the relationship between the therapeutic response and phototoxicity as it occurs in normal skin is not established. Comparative data on different psoralen molecules and their skin sensitizing ability are required. From studies on the skin concentration using HPLC and minimal phototoxic dose following oral administration, intraperitoneal administration, a bath of phototoxic drugs as a function of time in guinea pigs, the following results are obtained. 1. The skin concentration of phototoxic drugs after oral administration peaked at 1.5 hours, and the concentration of 8-methoxypsoralen(8-MOP) was 3.7 times greater than that of 5-methoxypsoralen(5-MOP). The skin concetration of 4,5,8-trimethylpsoralen(TMP) was not detected in this study(limit of sensitivity 5ng/g). 2. The skin conentration of phototoxic drugs after intraperitoneal administration peaked at 30 minutes, and the concentration of 8-MOP was slightly greater than that of 5-MOP. The skin concentration of TMP was not detected in this study(limit of sensitivity 5ng/g). 3. The skin concentration of phototoxic drugs after bathing peaked immediately after bathing, and the skin concentrations of phototoxic drugs after bathing decreased in the order of 5-MOP, TMP, and 8-MOP. 4. The minimal phototoxic dose of phototoxic drugs after oral administration was lowest at 1.5 hours, and the minimal phototoxic dose of 8-MOP was 8 times less than 5-MOP, 24 times less than TMP. The phototoxicity of 8-Mop after oral administration was strongest. The time of lowest phototoxic dose and highest skin concentration was the same. 5. The minimal phototoxic dose of phototoxic drugs after intraperitoneal administration was lowest at 30 minutes, and the minimal phototoxic dose of 8-MOP was 1.3 times less than 5-MOP, 5.7 times less than TMP. The phototoxicity of 8-MOP after intraperitoneal administration was strongest. The time of lowest phototoxic dose and highest skin concentration was same. 6. The minimal phototoxic dose of phototoxic drugs after bathing was lowest at 15 minutes. The minimal phototoxic dose of 8-MOP was not significantly different but was significantly greater than that of 5-MOP.

Anti-CD3 Antibody Induces IL-10-producing $CD4^+CD25^+$ Regulatory T Cells, Which Suppress T Cell Response in Rheumatoid Arthritis Patients

Yoon, Bo-Young,Cho, Mi-La,Hong, Yeon-Sik,Jhun, Joo-Yeon,Park, Mi-Kyung,Park, Kyung-Su,Park, Sung-Hwan,Kim, Ho-Youn The Korean Association of Immunobiologists 2007 Immune Network Vol.7 No.3

Background: Regulatory T cells (Tregs) have been investigated intensively for some decades. These cells regulate the immune system, prevent overactivated immune responses and can be used therapeutically. For rheumatoid arthritis (RA), understanding the functions and status of Tregs is an important step for understanding immune regulation in this autoimmune disease. Methods: We investigated the percentages, phenotypes and suppressive functions of $CD4^+CD25^+$ Tregs in peripheral blood (PB) of patients with RA. Results: The percentages were higher in the patients (n=12) than in healthy controls (n=10), and the cells expressed the $CD45RB^{low}$, CTLA-4 and CCR7 phenotypes. We also investigated the expression of Foxp3 and secretion of interleukin (IL)-10 induced $CD4^+CD25^+$ Tcells by anti-CD3 antibody treatment. A suppressive function of the patients' cells was shown through coculture with $CD4^+CD25^-$ T cells in vitro. Conclusion: We suggest that, despite their increased numbers and suppressive function, they manage the ongoing inflammation ineffectively. It might be possible to apply IL-10 to induce the proliferation of IL-10-producing Tregs as therapy for RA.

Circulating Concentrations of C-Peptide and Colorectal Adenoma

( Yoon Ji Choi ),( Young Ha Kim ),( Chang Ho Cho ),( Sung Hi Kim ),( Jung Eun Lee ) 한국임상영양학회 2014 Clinical Nutrition Research Vol.3 No.1

Hyperinsulinemia may increase the risk of colorectal neoplasia because of its mitogenic and antiapoptotic properties, which have a growth-promoting effect. We examined the association between circulating concentrations of C-peptide, a biomarker of insulin secretion, and colorectal adenoma prevalence in a case-control study of Korean adults. A total of 364 participants (112 cases and 252 controls) were included. Participants who underwent a colonoscopy completed questionnaires and provided blood samples. We used multivariate logistic regression models to obtain odds ratios (ORs) and 95% confidence intervals (CIs) for colorectal adenoma. Circulating concentrations of C-peptide were not associated with colorectal adenoma; the multivariate OR (95% CI) was 0.95 (0.51-1.75) comparing the highest tertile with the lowest tertile (p for trend = 0.91). When we used a conditional logistic regression model by fasting status and sex matching, there was still no association (OR = 0.92; 95% CI = 0.43-1.99) when comparing the highest tertile with the lowest tertile. We observed no association between circulating concentrations of C-peptide and colorectal adenoma prevalence in Korean adults.

New Synthesis of One-Dimensional 90/150 Linear Hybrid Group Cellular Automata

Cho, Sung-Jin,Choi, Un-Sook,Kim, Han-Doo,Hwang, Yoon-Hee,Kim, Jin-Gyoung,Heo, Seong-Hun IEEE 2007 IEEE transactions on computer-aided design of inte Vol.26 No.9

<P> In this paper, we propose a new method for the synthesis of 1-D 90/150 linear-hybrid-group cellular automata for CA-polynomials. We obtain large-cell CA very rapidly using our algorithm. This algorithm is efficient and suitable for all practical applications. </P>