• Genomics & Informatics
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• v.4 no.1
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• pp.11-15
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• 2006

The aim of this study is to identify hRad21-binding sites in human chromosome, the core component of cohesin complex that held sister chromatids together. After chromatin immunoprecipitation with an hRad21 antibody, it was cloned the recovered DNA and sequenced 30 independent clones. Among them, 20 clones (67%) contained repetitive elements including short interspersed transposable elements (SINE or Alu elements), long terminal repeat (LTR) and long interspersed transposable elements (LINE), fourteen of these twenty (70%) repeats clones had Alu elements, which could be categorized as the old and the young Alu Subfamily, eleven of the fourteen (73%) Alu elements belonged to the old Alu Subfamily, and only three Alu elements were categorized as young Alu subfamily. There is no CpG island within these selected clones. Association of hRad21 with Alu was confirmed by chromatin immunoprecipitation-PCR using conserved Alu primers. The primers were designed in the flanking region of Alu, and the specific Alu element was shown in the selected clone. From these experiments, it was demonstrated that hRad21 could bind to SINE, LTRs, and LINE as well as Alu.

• Animal cells and systems
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• v.6 no.4
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• pp.311-315
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• 2002

The RAD4 gene is essential for nucleotide excision repair in Saccharomyces cerevisiae. It has been known that the deduced amino acid sequence of Rad4 protein contains three DNA-dependent ATPase/helicase motifs. To determine the biochemical activities and functional role of RAD4 the Rad4 protein was expressed and purified. Immunoblot analysis showed a specific band of 21 kDa, which was well-matched with the size of open reading frame of the RAD4 gene. The purified Rad4 protein had no detectable helicase activity. However, the protein could interact with double stranded oligonucleotides, as judged by mobility shift assay. This result suggests that the Rad4 protein is a DNA binding protein.

• Molecules and Cells
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• v.45 no.11
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• pp.820-832
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• 2022

As a potential candidate to generate an everlasting cell source to treat various diseases, embryonic stem cells are regarded as a promising therapeutic tool in the regenerative medicine field. Cohesin, a multi-functional complex that controls various cellular activities, plays roles not only in organizing chromosome dynamics but also in controlling transcriptional activities related to self-renewal and differentiation of stem cells. Here, we report a novel role of the α-kleisin subunits of cohesin (RAD21 and REC8) in the maintenance of the balance between these two stem-cell processes. By knocking down REC8, RAD21, or the non-kleisin cohesin subunit SMC3 in mouse embryonic stem cells, we show that reduction in cohesin level impairs their self-renewal. Interestingly, the transcriptomic analysis revealed that knocking down each cohesin subunit enables the differentiation of embryonic stem cells into specific lineages. Specifically, embryonic stem cells in which cohesin subunit RAD21 were knocked down differentiated into cells expressing neural alongside germline lineage markers. Thus, we conclude that cohesin appears to control the fate determination of embryonic stem cells.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.338-347
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• 2008

Yeast RAD2, a yeast homolog of human XPG gene, is an essential element of nucleotide excision repair (NER), and its deletion confers UV sensitivity and NER deficiency. 6-Azauracil (6AU) sensitivity of certain rad2 mutants revealed that RAD2 has transcription elongation function. However, the fundamental mechanism by which the rad2 mutations confer 6AU sensitivity was not clearly elucidated yet. Using an insertional mutagenesis, PUF4 gene encoding a yeast pumilio protein was identified as a deletion suppressor of rad2${\Delta}$ 6AU sensitivity. Microarray analysis followed by confirmatory RT-qPCR disclosed that RAD2 and PUF4 regulated expression of HPT1 and URA3. Overexpression of HPT1 and URA3 rescued the 6AU sensitivity of rad2${\Delta}$ and puf4${\Delta}$ mutants. These results indicate that 6AU sensitivity of rad2 mutants is in part ascribed to impaired expression regulation of genes in the nucleotide metabolism. Based on the results, the possible connection between impaired transcription elongation function of RAD2/XPG and Cockayne syndrome via PUF4 is discussed.

• Journal of the Chungcheong Mathematical Society
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• v.14 no.1
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• pp.21-28
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• 2001

In this paper we show that the following results remain valid for arbitrary Jordan derivations as well: Let d be a derivation of a complex Banach algebra A. If $d^2(x){\in}rad(A)$ for all $x{\in}A$, then we have $d(A){\subseteq}rad(A)$ ([5, p. 243]), and in a case when A is unital, $d(A){\subseteq}rad(A)$ if and only if sup{$r(z^{-1}d(z)){\mid}z{\in}A$ invertible} < ${\infty}$([3]), where rad(A) stands for the Jacobson radical of A, and r(${\cdot}$) for the spectral radius.

• The Korean Journal of Nuclear Medicine
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• v.34 no.2
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• pp.144-153
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• 2000

Purpose: The purpose of this study was to evaluate the relationship between radiation-induced activation of DNA repair genes and radiation induced apoptosis in A431 cell line. Materials and Methods: Five and 25 Gys of gamma radiation were given to A431 cells by a Cs-137 cell irradiator. Apoptosis was evaluated by flow cytometry using annexin V-fluorescein isothiocyanate and propidium iodide staining. The expression of DNA repair genes was evaluated by both Northern and Western blot analyses. Results: The number of apoptotic cells increased with the increased radiation dose. It increased most significantly at 12 hours after irradiation. Expression of p53, p21, and hRAD50 reached the highest level at 12 hours after 5 Gy irradiation. In response to 25 Gy irradiation, hRAD50 and p21 were expressed maximally at 12 hours, but p53 and GADD45 genes showed the highest expression level after 12 hours. Conclusion: Induction of apoptosis and DNA repair by ionizing radiation were closely correlated. The peak time of inducing apoptosis and DNA repair was 12 hours in this study model. hRAD50, a recently discovered DNA repair gene, was also associated with radiation-induced apoptosis.

• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.145-154
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• 2001

A new type of modular mirror manipulator with independent adjustability was developed for the EPU6 beamline under construction at the Pohang Accelerator Laboratory. The mirror manipulator was designed so that the angular displacements of roll and pitch rotations do not introduce translational displacements and are independent with each other by positioning the mirror center to the center of a newly devised spherical joint. Manipulating its roll and pitch micrometers, the rotation angles of a dummy mirror were measured at an accuracy of 5 $\mu$rad using a gravity-referenced inclinometer. While the designed angular resolution was 3.937 $\mu$rad/$\mu\textrm{m}$, measured angular resolutions were 3.94 $\mu$rad/$\mu\textrm{m}$ for roll rotation and 3.85 $\mu$rad/$\mu\textrm{m}$ for pitch rotation. The effect of roll rotation on pitch angles was measured to be -3.18% and the effect of pitch rotation on roll angles was measured to be -5.21%. As the mirror manipulator was designed with emphases on independent adjustability and standardization, it results in eases of manufacturing, installation and adjustment as well as reductions of development period and design cost of mirror manipulators for various types of mirrors.

• Animal Bioscience
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• v.35 no.1
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• pp.126-137
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• 2022

Objective: Efficient gene editing technology is critical for successful knock-in in domestic animals. RAD51 recombinase (RAD51) gene plays an important role in strand invasion during homologous recombination (HR) in mammals, and is regulated by checkpoint kinase 1 (CHK1) and CHK2 genes, which are upstream elements of RAD51 recombinase (RAD51). In addition, mismatch repair (MMR) system is inextricably linked to HR-related pathways and regulates HR via heteroduplex rejection. Thus, the aim of this study was to investigate whether clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9)-mediated knock-in efficiency of human lactoferrin (hLF) knock-in vector in the bovine β-casein gene locus can be increased by suppressing DNA MMR-related genes (MSH2, MSH3, MSH6, MLH1, and PMS2) and overexpressing DNA double-strand break (DSB) repair-related genes (RAD51, CHK1, CHK2). Methods: Bovine mammary epithelial (MAC-T) cells were transfected with a knock-in vector, RAD51, CHK1, or CHK2 overexpression vector and CRISPR/sgRNA expression vector to target the bovine β-casein gene locus, followed by treatment of the cells with CdCl₂ for 24 hours. After 3 days of CdCl₂ treatment, the knock-in efficiency was confirmed by polymerase chain reaction (PCR). The mRNA expression levels of DNA MMR-related and DNA DSB repair-related genes were assessed by quantitative real-time PCR (RT-qPCR). Results: Treatment with CdCl₂ decreased the mRNA expression of RAD51 and MMRrelated genes but did not increase the knock-in efficiency in MAC-T cells. Also, the overexpression of DNA DSB repair-related genes in MAC-T cells did not significantly affect the mRNA expression of MMR-related genes and failed to increase the knock-in efficiency. Conclusion: Treatment with CdCl₂ inhibited the mRNA levels of RAD51 and DNA MMR-related genes in MAC-T cells. However, the function of MMR pathway in relation to HR may differ in various cell types or species.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.21-32
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• 2022

The importance of the classical theme of how the Top-of-Atmosphere (TOA) and Top-of-Canopy (TOC) reflectance of high-resolution satellite images match the actual atmospheric reflectance and surface reflectance has been emphasized. Based on the Radiometric Calibration Network (RadCalNet) BTCN and BSCN data, this study compared the accuracy of TOA and TOC reflectance products of the currently available optical satellites, including KOMPSAT-3, WorldView-2, and Pléiades-1A image sets calculated using the absolute atmospheric correction function of the Orfeo Toolbox (OTB) tool. The comparison experiment used data in 2018 and 2019, and the Landsat-8 image sets from the same period were applied together. The experiment results showed that the product of TOA and TOC reflectance obtained from the three sets of images were highly consistent with RadCalNet data. It implies that any imagery may be applied when high-resolution reflectance products are required for a certain application. Meanwhile, the processed results of the OTB tool and those by the Apparent Reflection method of another tool for WorldView-2 images were nearly identical. However, in some cases, the reflectance products of Landsat-8 images provided by USGS sometimes showed relatively low consistency than those computed by the OTB tool, with the reference of RadCalNet BTCN and BSCN data. Continuous experiments on active vegetation areas in addition to the RadCalNet sites are necessary to obtain generalized results.

• Korean Journal of Applied Biomechanics
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• v.21 no.4
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• pp.449-458
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• 2011

There are many functional methods for estimating the mean axis of rotation of a joint. However, it is still a controversial issue which method is superior. The purpose of this study was to compare functional methods for estimated axes of rotation from synthetic data. The comparison was made in terms of suitabilities on describing humans in sports. For a more practical situation, the axis error as well as measurement and marker movement error were applied to generated data. Simulations having 1000 times of 80 rotational displacements were performed. The functional methods used in the study were two transformation methods, two fitting methods, and one more transformation method called M. The M method is a combination of S$\ddot{o}$derk & Wedin(1993) and Mardia & Jupp(2000). Another factor of the study was angular velocity with levels of .01, .025, .05, .5 and 1 rad/s. The method M resulted in unbiased, stable, and consistent axis of rotation vectors in all levels of angular velocity except .01 rad/s. Therefore, the method M had the highest validity and reliability of all the methods. The fitting methods were very sensitive in small angular velocities and stable only in the velocities of more than .5 rad/s. The most suitable method for analyzing human motion by using marker photogrammetry is M.