• 대한핵의학회지
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• 제37권1호
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• pp.43-52
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• 2003

Microarray technology allows the simultaneous analysis of gene expression patterns of thousands of genes, in a systematic fashion, under a similar set of experimental conditions, thus making the data highly comparable. In some cases arrays are used simply as a primary screen loading to downstream molecular characterization of individual gene candidates. In other cases, the goal of expression profiling is to begin to identify complex regulatory networks underlying developmental processes and disease states. Microarrays were originally used with ceil lines or other simple model systems. More recently, microarrays have been used in the analysis of more complex biological tissues including neural systems and the brain. The application of cDNA arrays in neuropsychiatry has lagged behind other fields for a number of reasons. These include a requirement for a large amount of input probe RNA In fluorescent-glass based array systems and the cellular complexity introduced by multicellular brain and neural tissues. An additional factor that impacts the general use of microarrays in neuropsychiatry is the lack of availability of sequenced clone sets from model systems. While human cDNA clones have been widely available, high qualify rat, mouse, and drosophilae, among others are just becoming widely available. A final factor in the application of cDNA microarrays in neuropsychiatry is cost of commercial arrays. As academic microarray facilitates become more commonplace custom made arrays will become more widely available at a lower cost allowing more widespread applications. in summary, microarray technology is rapidly having an impact on many areas of biomedical research. Radioisotope-nylon based microarrays offer alternatives that may in some cases be more sensitive, flexible, inexpensive, and universal as compared to other array formats, such as fluorescent-glass arrays. In some situations of limited RNA or exotic species, radioactive membrane microarrays may be the most practical experimental approach in studying psychiatric and neurodegenerative disorders, and other complex questions in the brain.

• 대한의생명과학회지
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• 제10권2호
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• pp.75-84
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• 2004

Massive identification of differentially expressed patterns has been used as a tool to detect genes that are involved in disease related process. We employed circular single stranded sense molecules as probe DNA for a DNA chip. The circular single stranded DNAs derived from 1,152 unigene cDNA clones were purified in a high throughput mode from the culture supernatant of bacterial transformants containing recombinant phagemids and arrayed onto silanized slide glasses. The DNA chip was examined for its utility in detection of differential expression profile by using cDNA hybridization. Hybridization of the single stranded probe DNA were performed with Cy3- or Cy5-labeled target cDNA preparations at $60^\circ$C. Dot scanning performed with the hybridized slide showed 29 up-regulated and 6 down-regulated genes in a cancerous liver tissue when compared to those of adjacent noncancerous liver tissue. These results indicate that the circular single stranded sense molecules can be employed as probe DNA of arrays in order to obtain a precious panel of differentially expressed genes.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1377-1383
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• 2005

In a cDNA microarray experiment using Cy3 and Cy5 as labeling agents, particularly for the direct design, cDNAs from some genes incorporate one dye more efficiently than the other, which is referred to as the gene-specific dye bias. Dye-swaps, in which two dyes are switched on replicate arrays, are commonly used to control the gene-specific dye bias. We developed a simple procedure to extract the gene-specific dye bias information from a partial dye swap experiment. We detected gene-specific dye bias by identifying outliers in an X-Y plane, where the X axis represents the average log-ratio from two sets of dye swap pairs and the Y axis exhibits the average log ratio of four forward labeled arrays. We used this information for detecting differentially expressed genes, of which the additionally detected genes were validated by real-time RT-PCR.

• 대한소아치과학회지
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• 제29권2호
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• pp.278-284
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• 2002

RAW 264.7과 이것이 분화한 파골세포양 세포에서 파골세포 분화관련유전자의 전체적인 유전자 발현을 조사하기 위해 cDNA array 방법을 사용하였다. 1176 cDNA spot grid가 있는 Mouse Atlas cDNA array 결과를 확인하기 위하여 역전사 효소 중합반응 검사를 시행하였다. cDNA array 결과 6개의 유전자가 2.5% 이상 발현이 증가하였으며(PKC beta II, POMC, PTEN 등), 16개의 유전자가 2.5%이상 발현이 감소하였다(Osteopontin, Cyclin D1, Cathepsin C, PTMA 등). PKC beta II 유전자의 역전사-효소 중합 반응검사결과 이 유전자를 확인할 수 있었다. 파골세포 분화 결과 RAW 264.7세포주에 비해 파골세포양 세포에서 PKC beta II 유전자의 발현이 많았다. 파골세포 분화 관련 유전자는 RAW 264.7 세포주와 이것이 분화된 파골세포양 세포와 차이를 보였고, 이 유전자의 발현증가와 RAW 264.7 세포주의 파골세포 분화와 연관을 보였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권6호
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• pp.265-270
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• 2002

The determination of DNA hybridization reaction can apply the molecular biology research, clinic diagnostics, bioengineering, environment monitoring, food science and application area. So, the improvement of DNA hybridization detection method is very important for the determination of this hybridization reaction. Several molecular biological techniques require accurate predictions of matched versus mismatched hybridization thermodynamics, such as PCR, sequencing by hybridization, gene diagnostics and antisense oligonucleotide probes. In addition, recent developments of oligonucleotide chip arrays as means for biochemical assays and DNA sequencing requires accurate knowledge of hybridization thermodynamics and population ratios at matched and mismatched target sites. In this study, we report the characteristics of the probe and matched, mismatched target oligonucleotide hybridization reaction using thermodynamic method. Thermodynamic of 5 oligonucleotides with central and terminal mismatch sequences were obtained by measured UV-absorbance as a function of temperature. The data show that the nearest-neighbor base-pair model is adequate for predicting thermodynamics of oligonucleotides with average deviations for $\Delta$H$^{0}$ , $\Delta$S$^{0}$ , $\Delta$G$_{37}$ $^{0}$ and T$_{m}$, respectively.>$^{0}$ and T$_{m}$, respectively.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2002년도 춘계 학술발표회 논문집
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• pp.79-83
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• 2002

Since its introduction in 1995 by Schena et al. cDNA microarrays have been established as a potential tool for high-throughput analysis which allows the global monitoring of expression levels for thousands of genes simultaneously. One of the characteristics of the cDNA microarray data is that there is inherent noise even after the removal of systematic effects in the experiment. Therefore, replication is crucial to the microarray experiment. The assessment of reproducibility among replicates, however, has drawn little attention. Reproducibility may be assessed with several different endpoints along the process of data reduction of the microarray data. We define the reproducibility to be the degree with which replicate arrays duplicate each other. The aim of this note is to develop a novel measure of reproducibility among replicates in the cDNA microarray experiment based on the unprocessed data. Suppose we have p genes and n replicates in a microarray experiment. We first develop a measure of reproducibility between two replicates and generalize this concept for a measure of reproducibility of one replicate against the remaining n-1 replicates. We used the rank of the outcome variable and employed the concept of a measure of tracking in the blood pressure literature. We applied the reproducibility measure to two sets of microarray experiments in which one experiment was performed in a more homogeneous environment, resulting in validation of this novel method. The operational interpretation of this measure is clearer than Pearson's correlation coefficient which might be used as a crude measure of reproducibility of two replicates.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제8권2호
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• pp.177-193
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• 2005

목 적: 담즙정체를 보이는 환자의 간조직에서 cDNA microarray를 이용한 유전자 발현 분석을 통 하여 담도 폐쇄증의 발생과정에 관여하는 유전자를 규명하고자 연구를 시행하였다. 방 법: 환자의 간조직은 담즙정체를 보이는 11명의 환자로부터 진단적 간생검시 얻은 간조직의 일부를 이용하였다. 이들의 원인 질환은 담도 폐쇄증이 7명, 신생아 간염 증후군이 4명이었다. 정상대조군의 간조직은 생체부분 간이식시 성인 공여자로부터 얻은 간조직의 일부를 이용하였다. 간조직에서 분리된 mRNA를 4.7K 인간유전자 cDNA microarray를 이용하여 유전자 발현의 양상을 분석하였다. 결 과: 분석한 4,700종의 유전자 중 담즙정체 환자 11명 모두의 간조직에서 발현이 증가된 유전자는 17종이 발견되었고, 발현이 감소된 유전자는 20종이 발견되었다. 담도 폐쇄증 환자와 신생아 간염 증후군 환자 사이에 49종의 유전자에서 발현의 차이가 관찰되었고, 특히 담도 폐쇄증에서는 발현이 증가하였으나 신생아 간염 증후군에서는 발현이 감소된 유전자는 24종이었으며 이들 유전자 발현의 차이에 의해서 두 군간의 감별이 가능하였다. 결 론: 신생아 간질환에서 담도 폐쇄증 환자들은 모두 일정한 양상을 보여주어 이에 대한 분석을 통하여 담도 폐쇄증의 조기 감별 진단을 할 수 있을것을 시사하였다. 또한 담도 폐쇄증에서 특이 발현을 보이는 유전자의 추가적인 기능 연구를 시행함으로써 담도 폐쇄증의 원인을 규명하는데 도움을 줄 수 있을 것으로 생각한다.

• Fisheries and Aquatic Sciences
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• 제6권4호
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• pp.180-186
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• 2003

The full-length cDNA encoding the pre-protein growth hormone (sfGH) from spotted flounder (Verasper variegatus) was amplified by the rapid amplification of cDNA ends (RACE) using degenerated oligonucleotide primers derived from conserved growth hormone sequences. It consists of 901 nucleotides in length, including the coding region of 609 nucleotides, 111 nucleotides of a 5' untranslated region, and 181 nucleotides of a 3' untranslated region. The conserved polyadenylation signal (AATAAA) lies 12 bases upstream from the poly (A) tail. The deduced amino acid sequence shows an open reading frame encoding a pre-protein of 203 amino acids and a putative signal peptide of 17 amino acids, suggesting that the mature hormone consists of 186 amino acids. The analyses of sfGH reveal some unique structural features. The repetitive sequences are located in the 5' untranslated region of sfGH cDNA and consist of tandem arrays of imperfect direct repeat monomers. Moreover, sfGH contains six Cys residues, as opposed to four or five in other GHs, and it is clearly distinguishable from olive flounder (Paralichthys olivaceus) GH, which lacks a region corresponding to residues 175-188 in alignment positions. It has important implications from an evolutionary standpoint, suggesting possible divergence among flatfishes.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.291-291
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• 2010

Electron-beam lithography (EBL) process is a versatile tool for a fabrication of nanostructures, nano-gap electrodes or molecular arrays and its application to nano-device. However, it is not appropriate for the fabrication of sub-5 nm features and high-aspect-ratio nanostructures due to the limitation of EBL resolution. In this study, the precision assembly and alignment of DNA molecule was demonstrated using sub-5 nm nanostructures formed by a combination of conventional electron-beam lithography (EBL) and plasma ashing processes. The ma-N2401 (EBL-negative tone resist) nanostructures were patterned by EBL process at a dose of $200\;{\mu}C/cm2$ with 25 kV and then were ashed by a chemical dry etcher at microwave (${\mu}W$) power of 50 W. We confirmed that this method was useful for sub-5 nm patterning of high-aspect-ratio nanostructures. In addition, we also utilized the surface-patterning technique to create the molecular pattern comprised 3-(aminopropyl) triethoxysilane (APS) as adhesion layer and octadecyltrichlorosilane (OTS) as passivation layer. DNA-templated gold nanoparticle chain was attached only on the sub-5 nm APS region defined by the amine groups, but not on surface of the OTS region. We were able to obtain DNA molecules aligned selectively on a SiO2/Si substrate using atomic force microscopy (AFM).

• Genomics & Informatics
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• 제1권2호
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• pp.94-100
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• 2003

Motivation: Many have observed a nonlinear relationship between the signal intensity and the transcript abundance in microarray data. The first step in analyzing the data is to normalize it properly, and this should include a correction for the nonlinearity. The commonly used linear normalization schemes do not address this problem. Results: Nonlinearity is present in both cDNA and oligonucleotide arrays, but we concentrate on the latter in this paper. Across a set of chips, we identify those genes whose within-chip ranks are relatively constant compared to other genes of similar intensity. For each gene, we compute the sum of the squares of the differences in its within-chip ranks between every pair of chips as our statistic and we select a small fraction of the genes with the minimal changes in ranks at each intensity level. These genes are most likely to be non-differentially expressed and are subsequently used in the normalization procedure. This method is a generalization of the rank-invariant normalization (Li and Wong, 2001), using all available chips rather than two at a time to gather more information, while using the chip that is least likely to be affected by nonlinear effects as the reference chip. The assumption in our method is that there are at least a small number of non­differentially expressed genes across the intensity range. The normalized expression values can be substantially different from the unnormalized values and may result in altered down-stream analysis.