한국인에서 5,10-Methylenetetrahydrofolate Reductase 유전자 다형성 분석 및 임신의 결과에 미치는 영향

김아리 ( Ari Kim ),강은지 ( Eun Ji Kang ),이경아 ( Kyung A Lee ),박세나 ( Se Na Park ),박종순 ( Jong Soon Park ),박보현 ( Bo Hyun Park ),박혜숙 ( Hyesook Park ),박미혜 ( Mi Hye Park ),전선희 ( Sun Hee Chun ),안정자 ( Jung Ja Ahn ) 대한주산의학회 2006 大韓周産醫學會雜誌 Vol.17 No.3

목적: 본 연구는 한국인 임신 여성에서 MTHFR 유전자형 변이와 혈청내 호모시스테인 및 엽산의 농도와 이들이 임신에 미치는 영향을 알아보고자 하였다. 방법: 임신부 600명에게서 혈액을 채취하여 얻어진 DNA로 MTHFR C677T와 A1298C 유전자의 다형성을 PCR-RELP로 분석하였고 혈청내 호모시스테인은 HPLC 방법으로, 엽산은 RIA 방법으로 측정하였다. 결과: 혈청내 호모시스테인은 MTHFR C677T 유전자형이 C/C형이나 C/T인 군에 비해 T/T인 군에서 유의하게 높았으며 MTHFR A1298C 유전자형이 A/C형이나 C/C인 군에 비해 A/A인 군에서 역시 유의하게 높았다( p<0.05). 혈청 호모시스테인은 모든 MTHFR 유전자형에서 혈청 엽산농도와 역상관관계를 보였으나, 변이형 유전자형(T/T와 A/A유전자형)에서 더 큰 역 상관관계를 보였다. 15?mol/L 이상의 고호모시스테인혈증의 임신부에서 임신 주수와 출생체중이 36.1주, 3053.8 g으로 15 ?mol/L미만인 군의 38.3 주, 3215.3 g 보다 유의하게 낮았다( p<0.05). 결론: 혈청 호모시스테인의 농도는 MTHFR C677T와 A1298T 유전자의 다형성에 의해 영향을 받으며, MTHFR C677T와 A1298T 유전자의 다형성과 혈청 호모시스테인은 모두 임신주수와 신생아의 체중에 영향을 미친다. Objective: The purpose of this study was to analyze MTHFR polymorphism among the Korean population and to evaluate the relationship between serum levels of homocysteine and MTHFR polymorphism and also to investigate the effect on pregnancy outcomes. Methods: DNA was extracted from whole blood of 600 pregnant women. All samples were genotyped for the C677T and A1298C polymorphisms in MTHFR gene by PCR-RELP assay. Serum levels of homocysteine and folate were measured by high performance liquid chromatography for homocysteine and radioassay for folate. Pregnancy outcomes were estimated by gestational weeks and birth weights of newborns. Results: Serum homocysteine was higher in women with the T/T genotype than those with the C/T or C/C genotype of the MTHFR C677T polymorphism (p<0.05). And also serum homocysteine was higher in women with the A/A genotype than those with the A/C or C/C genotype of the MTHFR A1298C polymorphism (p<0.05). Serum homocysteine was negatively correlated with serum folate in all MTHFR genotypes, especially prominent in T/T genotype of MTHFR C677T polymorphism and A/A genotype of MTHFR A1298C polymorphism. Gestational age and the birth weight of infant from hyperhomocysteinemic mothers whose homocysteine levels higher than 15 μmol/L were 36.1 weeks, 3053.8 g, respectively, which were significant lower than those from normohomocysteinemic mothers (38.3 weeks, 3,215.3 g) (p<0.05). Conclusion: Serum homocysteine was influenced significantly by MTHFR C677T polymorphism and MTHFR A1298C polymorphism. MTHFR C677T and A1298C polymorphism and serum homocysteine levels affect pregnancy outcomes, although not mainly by serum folate level.

A Driving Method of Pixel Circuit Using a-IGZO TFT for Suppression of Threshold Voltage Shift in AMLED Displays

Woo-Sul Shin,Hyun-A Ahn,Jun-Seok Na,Seong-Kwan Hong,Oh-Kyong Kwon,Ji-Hun Lee,Jae-Gwang Um,Jin Jang,Sung-Hwan Kim,Jeong-Soo Lee IEEE 2017 IEEE electron device letters Vol.38 No.6

<P>A driving method of pixel circuit using amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) is proposed to improve the image quality of active matrix light-emitting diode displays. The proposed pixel circuit employs a diode-connected structure to compensate for variation in threshold voltage (V-th) of the a-IGZO TFT. In addition, the proposed driving method adopts negative bias annealing to suppress the V-th shift. The annealing time is optimized based on the experimental observation of the minimum V-th shift. After a stress time of 30 000 s, the measurement results showthat the (Vth) shift is reducedby 29.6%, using an optimized annealing time of 5% of one frame time. In addition, the maximum deviation in the emission current using the proposed driving method wasmeasured to be less than 4.32% after a stress time of 30 000 s.</P>

Synthesis and Antiproliferative Activity of Pyridinylcarbonylpyrimidines Against Melanoma Cell Line

Ahn, Hye-Mi,Lee, Jun-A,Kim, Hwan,Oh, Chang-Hyun,Lee, So-Ha,Sim, Tae-Bo,Hah, Jung-Mi,Kim, Dong-Jin,Yoo, Kyung-Ho Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.4

The synthesis of the series of pyrimidinylamines 1a-d and pyrimidinylureas 1e-u bearing a novel pyridinylcarbonylpyrimidine scaffold and their antiproliferative activities against A375 human melanoma cell line were described. Among them, three compounds 1e, 1h, and 1o showed superior antiproliferative activities to Sorafenib ($IC_{50}=5.5{\mu}M$) as a reference compound. In our series, urea compound 1o having 4-chloro-3-trifluoromethyl moiety on the benzene nucleus exhibited very good antiproliferative activity with $IC_{50}$ value of $1.4{\mu}M$.

선진기업복지제도 도입지원사업의 경제적 효과성 분석

권진아(Jin-A Kwon),안영규(Young-Gyu Ahn),김현수(Hyun-Soo Kim),박경일(Kyung-Il Park) 한국콘텐츠학회 2017 한국콘텐츠학회논문지 Vol.17 No.10

본 연구는 자료포락분석(DEA : Data Envelopment Analysis)을 이용하여 선진기업복지제도 실행에 따른 경제적 효과성을 분석하여, 중소기업들이 선진기업복지제도를 적극 도입 시행하도록 기여하는데 그 목적이 있다. 이를 위해, 설문회수 자료 중 투입-산출 지표와 관련된 3가지 유형의 - A유형(기본+심화, 도입)기업 36개, B유형(기본+심화, 미도입)기업 5개, C유형(기본, 미도입)기업 7개 - 총 48개 기업을 표본대상으로 하여 선진기업복지제도 도입과 관련된 경제적 효과성을 측정해 보았다. 분석 결과, 컨설팅을 받은 후 선진기업복지제도 중 어떤 하나의 제도라도 도입한 기업의 경제적 효과성이 컨설팅을 받은 후 관련 제도를 도입하지 않은 기업의 경제적 효과성보다 대체로 높게 나타나, 근로복지공단에서 실시하는 컨설팅을 통해 제도를 도입할 경우 긍정적인 경제적인 효과가 있음을 확인할 수 있었다. 이러한 연구결과를 통해 근로복지공단에서는 컨설팅을 보다 적극적으로 실시할 필요가 있으며 컨설팅만 받고 관련 제도 도입을 망설이는 기업을 찾아내고 그 이유에 대하여 구체적으로 파악해 볼 필요가 있음을 시사하고 있다. The purpose of this study is to analyze the economic effectiveness of advanced enterprise welfare system utilizing DEA(Data Envelopment Analysis) and contribute to the adoption and implementation of the system conducted by Korea Workers’ Compensation & Welfare Service(COMWEL). We classified 48 sample data into 3 categories : A category(basic consulting & intensive consulting, adoption) is 36, B category(basic consulting & intensive consulting, non-adoption) is 5, and C category(only basic consulting, adoption) is 7. A consulting fee is used as input variable, earning per employee and average employee tenure are used as output variables. As a result from DEA, we find out the fact that the economic effectiveness of A category is better than the economic effectiveness of B and C category and it comes to the conclusion that the consulting service provided by COMWEL has a positive effect on the adoption and implementation of advanced enterprise welfare system. Therefore, COMWEL is required to perform consulting service to small & medium business more actively and is needed to look at the reason why some businesses hesitate to accept the relevant system.

유방확대수술 환자에 대한 유방초음파 검사의 유용성

유현선(Hyun Sun Yoo),유민아(Min A Yoo),김상미(Sang Mi Kim),안미섭(Mi Seob Ahn),박원식(Won Sik Park) 대한초음파의료영상학회 2012 대한초음파의료영상학회지 Vol.3 No.1

목적 : 유방확대수술의 목적으로는 단순히 미용을 위한 성형과 유방암으로 의한 절제술 후 재건의 목적 이렇게 두 가지로 나눌 수 있다. 이러한 유방확대수술을 받은 환자가 증가함에 따라 합병증은 물론이고 유방에 삽입한 보형물이 유방실질을 가려 이상병변을 진단하기 어려운 경우도 점점 증가하고 있는 실정이다. 이에 따라 유방질환의 진단에 있어 기본이 되는 유방촬영술과 유방초음파를 비교하여 유방확대수술 환자에 대한 유방초음파의 유용성을 알아보고자 한다. 대상 및 방법 : 유방확대수술을 시행 받은 과거력이 있는 환자 중 2010년 1월부터 2011년 12월까지 암센터 유방 검사실에서 유방촬영술과 유방초음파를 모두 검사한 115명(평균연령 49세)을 대상으로 하였고 유방촬영장비는 Senography DS(GE), 초음파 장비는 IU22(Philips) L12-5MHz probe를 사용하였다. 미국방사선의학회에서 정한 유방영상판독 데이터 체계인BIRADS 분류법에 따라 나눈 6개의 Category로 결과를 분석하였는데 유방촬영술과 유방초음파 결과에서 Category가 각각 어떻게 다르게 나타났으며 실제 병리검사도 일치했는지 분석하였다. 이때, Category 1부터 Category 3까지는 양성소견으로 같은 Category로 묶어 분류하고, Category 4 이상은 악성의 심소견으로 역시 같은 Category로 묶어 분류하였다. 결과 : 첫째, 유방촬영술과 초음파 검사결과에서 모두 Category가 3이하로 양성소견으로 나온 환자는 73명이었고, Category가 4이상으로 악성이 의심된 환자는 8명이었는데 이 중 조직검사를 시행한 5명 모두 악성으로 진단되었다. 악성이 의심된 8명 중 3명은 외부병원에서 조직검사 결과 악성으로 진단되어 수술을 위하여 내원하였기 때문에 본원에서는 조직검사를 시행하지 않았다. 둘째, 초음파 검사결과에서 Category가 3이하로 양성소견으로 나왔지만 유방촬영술 결과에서 Category 4이상으로 악성이 의심된 환자는 4명이었는데 조직검사나 세포검사를 시행한 3명 중 3명 모두 양성의 결과가 나타났다. 나머지 1명은 조직검사를 하지 않고 6개월 후 추적검사를 하였는데 초음파 결과는 Category 2, 유방촬영술 결과 Category 3으로 판독되었다. 셋째, 유방촬영술 결과에서 Category가 3 이하로 양성소견으로 나왔지만 초음파 검사결과에서 Category 4 이상으로 악성이 의심된 환자는 30명이었는데 이 중 조직검사를 시행한 25명 중 1명은 양성, 24명은 모두 악성으로 진단되었다. 나머지 5명은 조직검사를 시행하지 않거나 본원에서의 추적검사를 시행하지 않아 추후의 확진 결과를 알 수 없었다. 유방촬영술 결과만을 보았을 때에 비해 초음파 검사 결과에서 나온 Category 결과가 조직검사나 세포검사를 시행하여 나온 병리결과와 일치하는 경우가 많았다. 결론 : 유방초음파는 유방확대수술을 시행 받은 환자에 있어서 촉지되는 종괴의 성질을 알아내고 유방촬영술 소견에서 감지가 불가능한 유방 보형물의 파열여부 등을 알아내어 환자의 이상병변을 알아내는 것에 있어서 유방촬영술보다 월등하며 방사선 노출의 위험이 없고 검사 시 통증을 많이 느끼는 유방촬영술에 비해 비침습적인 검사라 할 수 있다. 또한 유방촬영술의 보조적 검사법으로 이용되고 증가추세에 있는 MRI 검사에 비해 검사비용이 경제적이므로 유방확대수술 환자에 대한 screening 방법으로 유용성이 높다. 그러나 유방초음파 검사 한가지만으로는 100% 정확성을 기대할 수 없기 때문에 유방촬영술과 더불어 악성임이 의심된다면 영상대조도가 뛰어나고 객관적 평가가 용이한 MRI 검사와 함께 병행되어야 이상병변 진단의 정확성을 높일 수 있을 것이다. Purpose: Two main purposes of a breast implant surgery are a breast enlargement surgery as an elective plastic surgery and a breast reconstructive surgery for a patient who had mastectomy due to a breast cancer. As numbers of patients who have had breast implant surgeries has increased, complications of the surgery have increased as well as difficulty in diagnose of breast related diseases has increased because the breast implants blocks breast. This study was undertaken to discuss the benefits of a breast ultrasound exam to breast implanted patients through comparing a mammography and a breast ultrasound exam, which are primary diagnostic tests of breast related diseases. Sample and Methods: 115 women, who have had the breast implant surgery in past and have had both mammography and breast ultrasound exam between January 2010 and December 2011 at Samsung Medical Center, were conveniently recruited. Senography DS(GE) was used for mammography , and IU22(Philips) L12-5MHz probe was used for breast ultrasound exams. Breast Imaging-Reporting and Data System (BIRAD), which is a quality assurance tool to standardize reporting and originally published and trademarked by the American College of Radiology (ACR), was used as a method of categorizations. The results of categorization in mammography and breast ultrasound exams were top-down analyzed. Category 1 through category 3 were classified as a same category with positive results, and category 4 and above were also classified as another category with suspected malignant results. Results: At first, 73 women, who were classified as a category 3 or below for both mammography and breast ultrasound exams, had positive results. Among 8 women with suspected malignant results who were classified as a category 4 or above for both exams, all 5 women who had biopsy after the exams were confirmed with malignant results. Other 3 women among the 8 women did not have biopsy test at Samsung Medical Center because they were confirmed with malignant results at other health care facilities. Second, 4 women, who were classified as a category 3 or below for mammography and as a category 4 or above for breast ultrasound exams, resulted with suspected malignant. Among the 4 women, all 3 women, who had biopsy test or aspiration, were confirmed with positive results. The other 1 woman did not have biopsy test; however, she was classified as a category 2 for mammography and a category 3 for breast ultrasound exam on a 6 months follow-up. Third, 30 women were classified as a category 3 or below with positive results for mammography and as a category 4 or above with suspected malignant results for breast ultrasound exams. Among the 30 women, 25 women had biopsy test, and 24 women were confirmed with malignant result and 1 woman with a positive result. The other 5 women's results were not identified because they did not have biopsy test or no follow up was done. More results of categorizations for breast ultrasound exams were recorded, which were matched the pathologic outcomes of biopsy test and cytoscopy than the results of categorizations for mammography. Conclusion. Abreast ultrasound exam is more beneficial than a mammography in detecting significant findings through identifying characteristics of palpated breast mass of breast implanted patients and finding breakage of the implants, which mammography is not able to. The breast ultrasound exam is a less invasive diagnostic test comparing to mammography, which causes much pain to patients, with no danger of radiation exposure. Breast ultrasound exam is less expensive than MRI, which its use has increased as an accessorial diagnostic test of a mammography; therefore, it is a useful screening tool for breast implanted patients. Because it is difficult to expect having 100% accuracy in diagnosis with breast ultrasound exams, a mammography and MRI, which is used for objective evaluation and has a high definition in contrast, should be used with the b

A Highly Accurate Current LED Lamp Driver With Removal of Low-Frequency Flicker Using Average Current Control Method

Ahn, Hyun-A,Hong, Seong-Kwan,Kwon, Oh-Kyong Institute of Electrical and Electronics Engineers 2018 IEEE transactions on power electronics Vol.33 No.10

<P>This paper presents an average current control method for a light-emitting diode (LED) lamp driver that achieves a highly accurate current and removes low-frequency light flicker. The proposed LED lamp driver accurately maintains an average LED forward current by precisely adjusting the duration of the on- and off-times of the LED lamp driver. It also removes the low-frequency flicker by regulating the LED forward current without being affected by the low-frequency component of the ac line voltage. In addition, it reduces power consumption by eliminating the necessity of a high-voltage sensor or a high-side resistor, which causes conduction loss. The proposed average current controller was fabricated using a 0.18 μm bipolar, complementary metal-oxide-semiconductor, and double diffused metal-oxide-semiconductor process technology. The measurement results of the proposed LED lamp driver show that the variation in the average LED forward current is less than 0.6%, and the light flicker below 120 Hz is completely removed. In addition, the measured maximum power efficiency and power factor of the proposed LED lamp driver are 89.22% and 0.93, respectively.</P>

내분비계장애물질 평가방법의 최적화 및 Apoptosis에 관한 연구

안광현,이경아,김봉희 한국환경독성학회 2004 환경독성보건학회지 Vol.19 No.3

Xenoestrogens are chemicals with diverse structure that mimic estrogen Bisphenol A, a monomer of polycarbonate and epoxy resins, has been detected in canned food and human saliva Bisphenol A stimulate cell proliferation and induce expression of estrogen-response genes to vitro The purpose of the this study was to evaluate cell proliferation of bisphenol A in the presence of a rat liver S9 mix contaning cytochrome P450 enzyme~ and Cu(Ⅱ) The fragmentation of intact DNA, a parameter of apoptotic cell death, was evaluated quantitatively by diphenylamme reaction method Bisphenol A induced apoptotic cell death in a dose-dependent manner The effect of radical Scavenger on the apoptottc cell death induced bisphenol A was investigated The DNA fragmentation induced by bisphenol A was significantly inhibited by addition of radical scavenger to the culture medium This indicated that elevated oxidative stress caused by imbalance between the production and removal of free radicals occurred to cells Taken together, these results suggest that tree radical reacts with Cu(Ⅱ) leading oxidative stress

A Fast Switching Current Regulator Using Slewing Time Reduction Method for High Dimming Ratio of LED Backlight Drivers

Ahn, Hyun-A,Hong, Seong-Kwan,Kwon, Oh-Kyong IEEE 2016 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS PART 2 E Vol.63 No.11

<P>This brief proposes a fast switching current regulator to achieve a high dimming ratio of the light-emitting diode (LED) backlight drivers. The proposed current regulator employs the slewing time reduction method to enhance the dimming ratio by decreasing the rising time of the LED forward current. A six-channel LED backlight driver was fabricated using a 0.35-mu m bipolar-CMOS-DMOS process technology which includes an n-type MOSFET with a low voltage of 5 V and a high-side lateral double diffused MOSFET with a breakdown voltage of 60 V. The measured rising time and minimum pulsewidth of the LED forward current are reduced to 4.8 ns and 12 ns, respectively, at a current transition of 60 mA. Consequently, the dimming ratio of the LED backlight driver using the proposed current regulator is calculated to be 160 000 : 1 at a dimming frequency of 500 Hz, which is more than three times higher than that obtained using the previously reported current regulators. Therefore, the proposed current regulator is suitable for high-end displays which require high image quality.</P>

An Active Matrix Micro-Pixelated LED Display Driver for High Luminance Uniformity Using Resistance Mismatch Compensation Method

Ahn, Hyun-A,Hong, Seong-Kwan,Kwon, Oh-Kyong IEEE 2018 IEEE transactions on circuits and systems. a publi Vol.65 No.6

<P>This brief proposes an active matrix micro-pixelated light-emitting diode (AMLED) display driver to achieve a high luminance uniformity. The proposed AMLED display driver enhances the forward current uniformity of micro-LEDs by compensating for resistance mismatch between the micro-pixel circuits. The proposed AMLED display driver ICs were fabricated using a standard 0.18- <TEX>$\mu \text{m}$</TEX> CMOS process with 6-V high voltage devices. They were assembled with a micro-LED array having a resolution of <TEX>$16 \times 16 \times \text{RGB}$</TEX> and measured to verify the luminance uniformity of the AMLED display. The measured average deviation of the micro-LED forward current over all 768 pixels was 0.91% with an average current of 12.03 <TEX>$\mu \text{A}$</TEX>, indicating that the proposed display driver achieved highly uniform luminance. Therefore, the proposed AMLED display driver is suitable for high-end display applications, offering high image quality.</P>

소아의 메타콜린 기관지유발검사에서 PC₂₀-FEF_25%-75% 및 △FVC에 대한 분석

김현아 ( Hyeon A Kim ),권정은 ( Jung Eun Kwon ),안지영 ( Ji Young Ahn ),최재영 ( Jae Young Choe ),김동섭 ( Dong Sub Kim ),박숙현 ( Sook Hyun Park ),현명철 ( Myung Chul Hyun ),최봉석 ( Bong Seok Choi ) 대한천식알레르기학회(구 대한알레르기학회) 2021 Allergy Asthma & Respiratory Disease Vol.9 No.3

Purpose: Forced expiratory flow between 25% and 75% (FEF_25%-75%) is known to sensitively reflect bronchial obstruction. Methacholine challenge test (MCT) has shown varying reduction levels of forced vital capacity (FVC) with the reduction in forced expiratory volume in 1 second (FEV₁) in asthma. The aim of this study was to evaluate the clinical implication of provocative concentration causing a 20% fall in FEF_25%-75% (PC₂₀-FEF_25%-75%) and the percentage fall in FVC at the PC₂₀ dose of methacholine (△FVC). Methods: A total of 194 children who visited the hospital due to respiratory symptoms and underwent MCT were analyzed retrospectively. The patients were divided into 3 groups. Group I had both PC₂₀-FEV₁ and PC₂₀-FEF_25%-75% above 16 mg/mL; group II had a PC₂₀-FEF_25%-75% that fell below 16 mg/mL but PC₂₀-FEV₁ was 16 mg/mL or above; group III had a PC₂₀-FEV₁ and a PC₂₀-FEF_25%-75% that both fell below 16 mg/mL. Results: In group II, PC₂₀-FEV₁ was lower (P=0.026) and the rate of change in FEV₁ and FEF_25%-75% from baseline to 16 mg/mL of methacholine concentration was greater than in group I (both P<0.001). Levels of PC₂₀-FEF_25%-75% were higher in group II compared to group III (P<0.001). △FVC showed a correlation with PC₂₀-FEV₁ (P<0.001) only in the whole group. Conclusion: In asthmatic children, PC₂₀-FEF_25%-75% may be associated with bronchial hyperresponsiveness. △FVC was not associated with other parameters in either group. For subjects with a positive finding of PC₂₀-FEF_25%-75% and a negative finding of MCT, the progression to asthma can be suspected. (Allergy Asthma Respir Dis 2021;9:141-147)