저주파 혼변조 신호의 크기 조절에 의한 전치 왜곡 선형화기 설계

장미애,김영,Jang Mi-Ae,Kim Young 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.1

본 논문에서는 저주파 혼변조 신호의 크기만을 조절하여 혼변조 신호를 제어하는 새로운 전치 왜곡 선형화기를 제안하였다. 이 방법은 고조파 발생기 출력에서 생성된 저주파 혼변조 신호를 주 신호와 진폭 변조시켜 혼변조 신호를 만들었으며, 저주파 가변 이득 조절기를 이용하여 혼변조 신호의 크기와 위상을 조절하였다. 제안한 전치 왜곡 선형화기는 국내 셀룰러 기지국 송신 주파수($869{\sim}894\;MHz$) 반송파 2 톤 신호를 전력 증폭기에 인가하여 입력 신호 레벨을 변화시켰을 때, 3차 혼변조 신호는 20 dB 이상 개선되었으며, IS-95 CDMA 1FA 신호입력 시에는 중심 주파수에서 ${\pm}885\;kHz$ 및 ${\pm}1.25;MHz$ 이격 지점에서 인접 채널 전력 비(ACPR: Adjacent Channel Power Ratio)를 10 dB 이상 개선시켰다. In this paper, a new predistortion linearizer for controlling the amplitude of low frequency intermodulation distortion signals is proposed. The low frequency intermodulation distortion(IMD) components are generated by harmonic generator. A vector modulator, modulate fundamental signal with low frequency IMD signals, generates predistortion IMD signals and controls amplitude and phase of them with modulation factors. As a result, this predistorter is suppressed IMD signals of power amplifier effectively. The predistortion linearizer has been manufactured to operate in cellular base-station transmitting band($869{\sim}894\;MHz$). The experimental results show that IMD3 of power amplifier are improved more than 20 dB for CW two-tone signals. Also, it's improved the adjacent channel power ratio(ACPR) more than 10 dB for IS-95 CDMA IFA signals.

Novel Pathogenic Variant (c.3178G>A) in the SMC1A Gene in a Family With Cornelia de Lange Syndrome Identified by Exome Sequencing

장미애,이창우,김진경,기창석 대한진단검사의학회 2015 Annals of Laboratory Medicine Vol.35 No.6

Cornelia de Lange syndrome (CdLS) is a clinically and genetically heterogeneous congenital anomaly. Mutations in the NIPBL gene account for a half of the affected individuals. We describe a family with CdLS carrying a novel pathogenic variant of the SMC1A gene identified by exome sequencing. The proband was a 3-yr-old boy presenting with a developmental delay. He had distinctive facial features without major structural anomalies and tested negative for the NIPBL gene. His younger sister, mother, and maternal grandmother presented with mild mental retardation. By exome sequencing of the proband, a novel SMC1A variant, c.3178G>A, was identified, which was expected to cause an amino acid substitution (p.Glu1060Lys) in the highly conserved coiled-coil domain of the SMC1A protein. Sanger sequencing confirmed that the three female relatives with mental retardation also carry this variant. Our results reveal that SMC1A gene defects are associated with milder phenotypes of CdLS. Furthermore, we showed that exome sequencing could be a useful tool to identify pathogenic variants in patients with CdLS.

ABO 및 RhD 혈액형 검사와 항체 선별검사를 위한 혈액은행 자동화장비 Galileo NEO와 QWALYS-3의 평가

장미애,김대원,오종원,이승태,서지영 대한수혈학회 2014 大韓輸血學會誌 Vol.25 No.3

Background:An automation system for ABO-RhD typing and antibody screening has been developed and its use is increasing. We compared the results of ABO-RhD typing and antibody screening tests using the manual (ABO-RhD typing) or semiautomated (antibody screening) method and with the automation instruments Galileo NEO (Immucor Gamma, Norcoss, USA) and QWALYS-3 (DIAGAST, Loos Cedex, France). Methods:A total of 332 blood samples were tested for ABO-RhD typing in comparison with routine manual tests, and 236 samples for antibody screening in comparison with DS-Screening II (Bio-Rad Laboratories, 1785 Cressier FR, Switzerland). We evaluated the performance of Galileo NEO and QWALYS-3 in terms of concordance, carryover, and sensitivity test for ABO-RhD typing and antibody screening. Results:The concordance rates of ABO-RhD typing results between the manual methods and the two instruments were 99.4% for Galileo NEO and 99.1% for QWALYS-3, respectively. On antibody screening tests, a concordance rate of 97.9% was observed between the semiautomated method and Galileo NEO or QWALYS-3, because of discordance in five specimens. The carryover was not observed for ABO-RhD typing and antibody screening. The overall sensitivity of the two automation instruments appears to be parallel with that of DS-Screening II except for anti-E. Conclusion:The Galileo NEO and QWALYS-3 system showed good performance, it can be used with confidence for routine pre-transfusion testing in the blood bank.

Identification of p.Glu131Lys Mutation in the IHH Gene in a Korean Patient With Brachydactyly Type A1

장미애,김옥화,김선욱,기창석 대한진단검사의학회 2015 Annals of Laboratory Medicine Vol.35 No.3

Identification of a Novel De Novo Variant in the PAX3 Gene in Waardenburg Syndrome by Diagnostic Exome Sequencing: The First Molecular Diagnosis in Korea

장미애,이태현,이준남,조은해,기창석 대한진단검사의학회 2015 Annals of Laboratory Medicine Vol.35 No.3

Waardenburg syndrome (WS) is a clinically and genetically heterogeneous hereditary auditory pigmentary disorder characterized by congenital sensorineural hearing loss and iris discoloration. Many genes have been linked to WS, including PAX3, MITF, SNAI2, EDNRB, EDN3, and SOX10, and many additional genes have been associated with disorders with phenotypic overlap with WS. To screen all possible genes associated with WS and congenital deafness simultaneously, we performed diagnostic exome sequencing (DES) in a male patient with clinical features consistent with WS. Using DES, we identified a novel missense variant (c.220C>G; p.Arg74Gly) in exon 2 of the PAX3 gene in the patient. Further analysis by Sanger sequencing of the patient and his parents revealed a de novo occurrence of the variant. Our findings show that DES can be a useful tool for the identification of pathogenic gene variants in WS patients and for differentiation between WS and similar disorders. To the best of our knowledge, this is the first report of genetically confirmed WS in Korea.

Identification of MECP2 Duplication Using Low-Depth Whole-Genome Sequencing-Based Copy Number Variation Analysis

장미애,박소영,박종은,김영은,기창석 대한진단검사의학회 2020 Laboratory Medicine Online Vol.10 No.2

Effect of Accreditation on Accuracy of Diagnostic Tests in Medical Laboratories

장미애,윤영안,송정한,김정호,민원기,이지성,이용화,이유경 대한진단검사의학회 2017 Annals of Laboratory Medicine Vol.37 No.3

Background: Medical laboratories play a central role in health care. Many laboratories are taking a more focused and stringent approach to quality system management. In Korea, laboratory standardization efforts undertaken by the Korean Laboratory Accreditation Program (KLAP) and the Korean External Quality Assessment Scheme (KEQAS) may have facilitated an improvement in laboratory performance, but there are no fundamental studies demonstrating that laboratory standardization is effective. We analyzed the results of the KEQAS to identify significant differences between laboratories with or without KLAP and to determine the impact of laboratory standardization on the accuracy of diagnostic tests. Methods: We analyzed KEQAS participant data on clinical chemistry tests such as albumin, ALT, AST, and glucose from 2010 to 2013. As a statistical parameter to assess performance bias between laboratories, we compared 4-yr variance index score (VIS) between the two groups with or without KLAP. Results: Compared with the group without KLAP, the group with KLAP exhibited significantly lower geometric means of 4-yr VIS for all clinical chemistry tests (P<0.0001); this difference justified a high level of confidence in standardized services provided by accredited laboratories. Confidence intervals for the mean of each test in the two groups (accredited and non-accredited) did not overlap, suggesting that the means of the groups are significantly different. Conclusions: These results confirmed that practice standardization is strongly associated with the accuracy of test results. Our study emphasizes the necessity of establishing a system for standardization of diagnostic testing.

Simultaneous Occurrence of Angioimmunoblastic T-cell Lymphoma and Plasma Cell Leukemia

장미애,이승태,김희진,김석진,김선희 대한진단검사의학회 2015 Annals of Laboratory Medicine Vol.35 No.1

Identification of a Rare 3 bp BRAF Gene Deletion in a Thyroid Nodule by Mutant Enrichment with 3ʹ-Modified Oligonucleotides Polymerase Chain Reaction

장미애,이승태,오영련,김선욱,정재훈,기창석,김종원 대한진단검사의학회 2012 Annals of Laboratory Medicine Vol.32 No.3

Papillary thyroid carcinoma (PTC) is the most common malignant thyroid tumor, and 36-69% of PTC cases are caused by mutations in the BRAF gene. The substitution of a valine for a glutamic acid (V600E) comprises up to 95-100% of BRAF mutations; therefore, most diagnostic methods, including allele-specific PCR and real-time PCR, are designed to detect this mutation. Nevertheless, other mutations can also comprise the genetic background of PTC. Recently, a novel and sensitive technique called mutant enrichment with 3’-modified oligonucleotides (MEMO) PCR has been introduced. When we applied allele-specific PCR and MEMO-PCR for the detection of the BRAF V600E mutation, we found an unusual 3’ bp deletion mutation(c.1799_1801delTGA) only when using MEMO-PCR. This deletion results in the introduction of a glutamic acid into the B-Raf activation segment (p.V600_K601delinsE), leading to an elevated basal kinase activity of BRAF. This is the first report of a rare 3 bp BRAF deletion in a PTC patient that could not be detected by allele-specific PCR.

대구지역 중학생들의 학교 급식 만족도 조사

장미애,최미자,Jang Mi-Ae,Choi Mi-Ja 동아시아식생활학회 2005 동아시아식생활학회지 Vol.15 No.2

A study was conducted to improve satisfaction to school food service and to furnish source materials for nutrient education by researching degree of satisfaction of middle school students to school food service. Following results are from the study that targeted 215 male students and 173 female students in 5 middle schools in Daegu. Satisfaction rates regarding taste of foods, smell, proper temperature, use of seasonal food, cafeteria atmosphere, numbers of side dishes, and kindness of the cook in a cafeteria were higher than dissatisfaction. And dissatisfaction rates were higher in quantity and quality of foods, sanitation, purity of table wares, opening to nutrient education and related informations for students, opinion reflection of students, food serving time and gratification to food serving than the opposite. But the degree of general satisfaction on school food service were higher than the degree of general dissatisfaction. Sanitation was the first thing to be changed in school food service, then quantity of food and taste for the last. And there were notable differences between male students and female students in sanitation satisfaction. The variables that influence on satisfaction to school food service were sanitary administration, numbers of side dishes, quantity of foods, nutrient, smell and taste when ranked. And the main three things that have similar rate in quantity with satisfaction rate are taste, smell and nutrient of school food service. Through these followed results, degree of general satisfactions to school food service were higher than degree of general dissatisfactions. But sanitation, quantity and quality of foods, taste, and food serving size were not satisfactory for students in rate. Therefore it has to be improved to enhance satisfactions to middle school food service.