AI 조성비 변화에 따른 GaAs/AIGaAs 다중양자우물구조 특성변화 연구

유연희,최정우,임재영,노삼규 慶熙大學校 材料科學技術硏究所 1998 材料科學技術硏究論集 Vol.11 No.-

We manufactured and characterized different sets of GaAs/AlGaAs multiple quantum well structures for the long wavelength infrared photodetection. The samples were grown by MBE. We changed the aluminum composition of barrier region from 0.24 to 0.30 in 0.02 steps, and performed double crystals X-ray diffraction(DCXRD) and the photoluminescence measurements. DCXRD measurements correctly gave the expected aluminum compositions. Photoluminescence measurements revealed that the ground state energy of the well increases with composition as desired, but the change was not very significant.

무선 기반의 실내 온도 측정 시스템 설계

차부상,정우철,류정탁,김연보 대구대학교 정보통신연구소 2004 情報通信硏究 Vol.3 No.2

최근 홈 네트워크 산업이나 지능형 주거관리 시스템의 필요성과 관심이 증가하고 있다. 이와 같은 분야에서는 무엇보다 효율적인 측정 시스템에 대한 연구가 선행되어야 한다. 따라서 본 논문에서는 센서 측정 시스템 설계에 관한 기초 연구로서 실내 환경에 적합한 온도 측정 시스템을 설계해 보고 그 특성에 대해 나타내었다. 설계한 시스템의 구성은 크게 온도 센서로부터 온도 변화를 검출하는 데이터 획득부, 신호처리를 위한 제어부 그리고 측정된 온도 데이터를 전송하기 위한 RF 송수신부로 나누어진다. 설계된 측정 시스템에 거리변화 및 장애물 유무에 따른 영향을 살펴보고, 안테나 변경에 따른 성능 차이를 살펴보았다. 실험 결과 10m 이내의 실내 환경에서는 본 논문에서 제안하고 설계한 측정 시스템을 사용하여 데이터의 실시간 처리가 가능하였다. 또한 이를 바탕으로 다중 센서 측정 시스템 구현이 가능함을 알 수 있었다. Recently, the need for intelligent sweet home systems and home network industry is increasing. In this field, a study on efficient measurement system is preceded by the other subjects. Therefore, in this paper, a study on efficient sensor measurement system, temperature measurement system suitable for room environment is designed and its property is given. We designed temperature measurement systems consisting of data acquisition part as a temperature sensor, control unit for signal processing and RF moduls for data transmit. The results of experiment showed real-time processing in the room environment within 10 meter. It also showed the possibility of multi-sensors measurement system.

Kinetics and Rate of Enzymatic Hydrolysis of Cellulose in Supercritical Carbon Dioxide

Ryu, Yeon Woo,Park, Chang Yeol,KIM, CHUL 한국화학공학회 2001 Korean Journal of Chemical Engineering Vol.18 No.4

Experiments were carried out on the application of supercritical fluid to the hydrolysis of cellulose by the enzyme, cellulase. The stability of cellulase was sustained at the pressures of up to 160 atm for 90 min at 50℃ in supercritical carbon dioxide. In the hydrolysis of cellulose the glucose yield was 100% at supercritical condition. Kinetic constants of hydrolysis at supercritical condition were increased as compared to those at atmospheric condition. The hydrolysis reaction was found competitively inhibited by glucose at supercritical condition.

Selective Isolation and Characterization of Schwanniomyces castellii Mutants with Increased Production of α-Amylase and Glucoamylase

RYU, YEON WOO,KO, SUNG HWAN 한국미생물 · 생명공학회 1993 Journal of microbiology and biotechnology Vol.3 No.2

This study was carried out to isolate and characterize the mutant strains of Schwanniomyces castellii NRRL Y-2477. Mutants were prepared with the treatment of ethyl methane sulfonate. 2-deoxy-D-glucose resistant mutants were isolated and two mutants were selected based on their high production of amylolytic enzymes and their ability to ferment starch. The mutants selected had higher α-amylase and glucoamylase activities than the wild type strain from several other carbon sources. Especially, it was revealed that mutant strain M-9, when cultured in the presence of glucose as a sole carbon source, shows relatively high activities of α-amylase and glucoamylase compared to those of the wild type strain. In result, this mutant strain can be considered as a constitutive producer of amylolytic enzymes. To compare the ethanol production ability of wild type strain and of mutant strains selected, an alcohol fermentation was carried out using 100g/ℓ soluble starch. Mutant strain M-9 did not improve the direct alcohol fermentation of starch, despite its excellent amylolytic activities performance. On the other hand, mutant strain M-6 produced 37.9g/ℓ (4.8%, v/v) ethanol by utilizing about 82% of substrate.

Enhancement of Ethanol Tolerance of Lactose Assimilating Yeast Strain by Protoplast Fusion

Ryu, Yeon Woo,Jang, Heang Wook,Lee, Haing Sook 한국미생물 · 생명공학회 1991 Journal of microbiology and biotechnology Vol.1 No.3

In order to construct a yeast strain having high ethanol tolerance together with good lactose fermentation ability, the protoplast fusion using Saccharomyces cereuisiae STV 89 and Kluyveromyces fragilis CBS 397 was carried out. Auxotrophic mutants of K. fragilis were obtained as a selection marker by treatment of ethylmethane sulfonate. The best mutant for protoplast fusion was selected based on the capabilities of β-galactosidase production and lactose fermentation. The protoplast fusion using polyethylene glycol and calcium chloride solution led to the fusion frequence of 3×10 exp (-6) and a number of fusants were obtained. Among these fusants, a fusant F-3-19 showed the best results in terms of ethanol tolerance, β-galactosidase activity and lactose fermentation. The performance of lactose fermentation and ethanol tolerance by this fusant were better than those of K. fragilis. Study on the ethanol tolerance having relation to fatty acid composition and intracellular ethanol concentration revealed that the fusant F-3-19 had a higher unsaturated fatty acids content and accumulated less amount of intracellular ethanol compared with a parent of K. fragilis.

Selective Isolation and Characterization of Schwanniomyces castellii Mutants with Increased Production of a-Amylase and Glucoamylase

Ryu, Yeon-Woo The Korean Society for Microbiology and Biotechnol 1993 Journal of microbiology and biotechnology Vol.3 No.2

This study was carried out to isolate and characterize the mutant strains of Schwanniomyces castellii NRRL Y-2477. Mutants were prepared with the treatment of ethyl methane sulfonate. 2-deoxy-D-glucose resistant mutants were isolated and two mutants were selected based on their high production of amylolytic enzymes and their ability to ferment starch. The mutants selected had higher a-amylase and glucoamylase activities than the wild type strain from several other carbon sources. Especially, it was revealed that mutant strain M-9, when cultured in the presence of glucose as a sole carbon source, shows relatively high activities of a-amylase and glucoamylase compared to those of the wild type strain. In result, this mutant strain can be considered as a constitutive producer of amylolytic enzymes. To compare the ethanol production ability of wild type strain and of mutant strains selected, an alcohol fermentation was carried out using 100 g/l soluble starch. Mutant strain M-9 did not improve the direct alcohol fermentation of starch, despite its excellent amylolytic activities performance. On the other hand, mutant strain M-6 produced 37.9 g/l (4.8%, v/v) ethanol by utilizing about 82% of substrate.

Effect of Oxygen and Unsaturated Fatty Acids on the Ethanol Tolerance of Yeast Strains

Ryu, Yeon Woo,Jang, Heang Wook 한국미생물 · 생명공학회 1991 Journal of microbiology and biotechnology Vol.1 No.1

This study deals with investigation of the ethanol tolerance of yeast strains with respect to fatty acid composition and intracelluar ethanol concentration during alcohol fermentation. The cell viabilities and fermentation abilities of Saccharomyces cerevisiae and Kluyveromyces fragilis were improved by aeration and addition of unsaturated fatty acids into growth medium. Aeration decreases the accumulation of ethanol, while increases unsaturated fatty acid contents inside yeast cells. Thus it was found that oxygen and unsaturated fatty acids play decisive roles in the increase of ethanol tolerance of yeasts.

Prenatal diagnosis of a de novo ring chromosome 11

Ju-Yeon Park,Moon-Hee Lee,Bom-Yi Lee,Yeon-Woo Lee,Hyun-Mee Ryu,So-Yeon Park 대한의학유전학회 2007 대한의학유전학회지 Vol.4 No.1

고리염색체(Ring chromosome)는 매우 낮은 빈도로 발견되는 염색체 이상으로 모든 번호에서 보고되고 있으며 특히 끝곁 매듭 염색체(acrocentric chromosome)에서 빈번하게 관찰 된다. 본 증례는 ring chromosome(고리염색체)11의 산전진단에 관한 것이다. 산모는 36세의 여성으로 모체혈청검사에서 에드워드 증후군의 표시인자가 증가되어, 태아의 염색체 검사를 위해 임신 19.5주에 양수천자술을 시행하였다. 결과는 46,XX,r(11)[65]/45,XX,-11[16]/46,XX[34]로 고리염색체(ring chromosome) 11이 mosaic으로 관찰되었다. 혈액을 이용한 부모 염색체 검사는 모두 정상이었다. 임신 20주에 실시된 정밀초음파 검사에서는 자궁내성장장애(IUGR) 소견을 보였다. 모자익시즘의 확인을 위해 임신 22주에 재대 혈액을 이용한 두번째 염색체검사 결과는 46,XX,r(11)(p15.5q24.2)[229]/45,XX,-11 [15]이었으며 첫번째 검사에서 관찰되지 않았던 다양한 형태의 고리염색체(ring chromosome)가 소수의 세포에서 관찰되었다. 고리염색체(ring chromosome)11에 대한 FISH 검사에서는 11 염색체의 장완과 11 염색체의 단완의 subtelomeric 부위가 결실되어 있었다. A 36-year-old pregnant woman was referred for amniocentesis at 19.5 weeks gestation because of advanced maternal age and evidence of increased risk for Edward syndrome in the maternal serum screening test. Cytogenetic analysis of the cultured amniotic fluid cells revealed mosaicism for ring chromosome 11: 46,XX,r(11)[65]/45,XX,-11[16]/46,XX[34]. Parental karyotypes were normal. A targeted ultrasound showed intrauterine growth restriction (IUGR). Cordocentesis was performed to characterize the ring chromosome and to rule out tissue specific mosaicism. Karyotype was confirmed as 46,XX,r(11) (p15.5q24.2)[229]/45,XX,-11[15]. And a few new form of ring were detected in this culture. The deletion of subtelomeric regions in the ring chromosome were detected by fluorescent in situ hybridization (FISH ). The pregnancy was terminated. The fetal autopsy showed a growth-retarded female fetus with rocker bottom feet. We report a case of prenatally detected a de novo ring chromosome 11.

자연 유산에서 드물게 관찰된 Jumping translocation 2례

이연우(Yeon Woo Lee),이봄이(Bom Yi Lee),박주연(Ju Yeon Park),최은영(Eun Young Choi),오아름(Ah Rum Oh),이신영(Shin Young Lee),류현미(Hyun Mee Ryu),강인수(Inn Soo Kang),양광문(Kwang Moon Yang),박소연(So Yeon Park) 대한의학유전학회 2010 대한의학유전학회지 Vol.7 No.1

Jumping translocation (JT)은 여러 세포주에서 하나의 공여 염색체가 둘 이상의 수여 염색체와 염색체 재배열을 보이는 염색체의 구조적 이상으로 종양 세포인 림프성 혈액암에서 빈번하게 관찰되는 획득성(acquired) JT에 비해 체질성(con-stitutional) JT는 매우 드물게 보고되고 있다. 본 증례에서는 자연 유산된 수태산물에서 관찰된 체질성 JT 2례를 보고하고자 한다. 증례 1은 임신 7주 유산아 조직의 세포유전학적 검사에서 핵형분석 결과는 46,XY,add(18)(p11.1)[61]/45,XY,der(18;21)(q10;q10)[32]/46,XY,-18,+mar[16]/46,XY,i(18)(q10)[9]/45,XY,der(15;18)(q10;q10)[6]/46,XY,+1,dic(1;18)(p22;p11.1)[2]/45,XY,der(13;18)(q10;q10)[1]/46,XY[32]로 관찰되었다. 공여 염색체는 18번이고 수여 염색체는 1, 13, 15, 18, 21번이었다. 증례 2는 임신 6주째 자연 유산된 유산아 조직으로부터 세포 유전학적 검사를 실시한 결과, 핵형은 46,XY,der(22)t(9;22)(q12;q13)[22]/46,XY,der(22)t(1;22)(q21;q13)[13]/46,XY,add(22)(q13)[5]/46,XY[23]고 관찰되었다. 공여 염색체는 22번이고 수여 염색체는 1, 9번이었다. 2례 모두 de novo였고 acrocentric 염색체를 수반하였으며 절단점은 대부분 중심절과 중심절 주위, 말단체에 존재하였다. 본 증례는 매우 드물게 관찰되는 체질성 JT로서 임신 초기 세포 분열 단계에서 발생했고 다양한 세포주에서 나타난 비정상 핵형으로 인해 정상적인 배발달이 이루어지지 못하여 자연 유산된 것으로 생각된다. Jumping translocations (JT) are chromosomal rearrangements involving one donor chromosome and several recipient chromosomes. While JTs are frequently observed as acquired chromosomal abnormalities in hematologic malignancies, constitutional JTs are only rarely reported. We report two cases of constitutional JT in chorionic villi derived from the products of conception. The karyotype of the first case was 46,XY,add(18)(p11.1)[61]/45,XY,der(18;21)(q10;q10)[32]/46,XY,-18,+mar[16]/46,XY,i(18)(q10)[9]/45,XY,der(15;18)(q10;q10)[6]/46,XY,+1,dic(1;18)(p22;p11.1)[2]/45,XY,der(13;18)(q10;q10)[1]/46,XY[32]. The donor was a chromosome 18. The recipient chromosomes were chromosomes 1, 13, 15, 18 and 21. In the second case, the karyotype was 46,XY,der(22)t(9;22)(q12;q13)[22]/46,XY,der(22)t(1;22)(q21;q13)[13]/46,XY,add(22)(q13)[5]/46,XY[23]. The donor was a chromosome 22 and recipients were chromosomes 1 and 9. Both cases were de novo. The breakpoints of chromosomes were mostly in centromeric regions, pericentromeric regions, or telomeric regions. Normal cell lines were observed in both cases. This report supports the prior findings that the unstable nature of JT, resulting in chromosomal imbalance, most likely contributed to these early miscarriages.

Association Between Serum Bilirubin and Atrial Fibrillation: A Mendelian Randomization Study

Si-Woo Kim,Jung-Ho Yang,Sun-Seog Kweon,Young-Hoon Lee,Seong-Woo Choi,So-Yeon Ryu,Hae-Sung Nam,Hye-Yeon Kim,Min-Ho Shin 대한심장학회 2023 Korean Circulation Journal Vol.53 No.7

Background and Objectives: The association between bilirubin and atrial fibrillation (AF) has been evaluated previously in observational studies but with contradictory results. This study evaluated the causal association between serum bilirubin level and AF using Mendelian randomization (MR) analysis. Methods: This cross-sectional study includes 8,977 participants from the Dong-gu Study. In the observational analysis, multivariate logistic regression was performed to evaluate the association between bilirubin and prevalent AF. To evaluate the causal association between bilirubin and AF, MR analysis was conducted by using the UGT1A1 rs11891311 and rs4148323 polymorphisms as instrumental variables. Results: Elevated serum bilirubin levels were associated with an increased risk for AF in observational analysis (total bilirubin: odds ratio [OR], 1.31; 95% confidence interval [95% CI], 1.15–1.48 per 1 standard deviation [SD]; direct bilirubin: OR, 1.31; 95% CI, 1.18–1.46 per 1 SD), whereas the genetically predicted serum bilirubin levels in MR analysis did not show this association (total bilirubin: OR, 1.02; 95% CI, 0.67–1.53 per 1 SD; direct bilirubin: OR, 1.03; 95% CI, 0.61–1.73 per 1 SD). Conclusions: Genetically predicted bilirubin levels were not associated with prevalent AF. Thus, the observational association between serum bilirubin levels and AF may be non-causal and affected by reverse causality or unmeasured confounding.