• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.1
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• pp.71-77
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• 2015

Ultrasonic imprinting is a micropattern replication technology for a thermoplastic polymer surface that uses ultrasonic vibration energy; it has the advantages of a short cycle time and low energy consumption. Recently, ultrasonic imprinting has been further developed to extend its functionality: (i) selective ultrasonic imprinting using mask films and (ii) repetitive ultrasonic imprinting for composite pattern development. In this study, selective ultrasonic imprinting was combined with repetitive imprinting in order to replicate versatile micropatterns. For this purpose, a repetitive imprinting technology was further extended to utilize mask films, which enabled versatile micropatterns to be replicated using a single mold with micro-prism patterns. The replicated hybrid micropatterns were optically evaluated through laser light images, which showed that versatile optical diffusion characteristics can be obtained from the hybrid micropatterns.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.893-899
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• 2009

Few studies have reported the existence of imprinted genes in cattle compared to the human and mouse. Genomic imprinting is expressed in monoallelic form and it depends on a single parent-specific form of the allele. Comparative analysis of mammals other than the human is a valuable tool for explaining the genomic basis of imprinted genes. In this study, we investigated 34 common imprinted genes in the human and mouse as well as 35 known non-imprinted genes in the human. We found short interspersed nuclear elements (SINEs), long interspersed nuclear elements (LINEs), and long terminal repeats (LTRs) in imprinted (human and mouse) and control (cattle) genes. Pair-wise comparisons for the three species were conducted using SINEs, LINEs, and LTRs. We also calculated 95% confidence intervals of frequencies of repetitive sequences for the three species. As a result, most genes had a similar interval between species. We found 11 genes with conserved SINEs, LINEs, and LTRs in the human, mouse, and cattle. In conclusion, eleven genes (CALCR, Grb10, HTR2A, KCNK9, Kcnq1, MEST, OSBPL5, PPP1R9A, Sgce, SLC22A18, and UBE3A) were identified as candidate imprinted genes in cattle.

• Transactions of Materials Processing
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• v.22 no.1
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• pp.36-41
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• 2013

The present study examines the micro-pattern replication on a plastic film using ultrasonic imprinting. Ultrasonic imprinting uses ultrasonic waves to generate repetitive microscale deformation in the polymer film. The resulting deformation heat on the surface of the film causes the surface region to soften sufficiently so that a replication of the micro-pattern can be obtained. To successfully replicate the micro-pattern on a large area of polymer film, a high replication ratio is needed as well as good uniformity over the entire region. In this study, a horn design is investigated by finite element analysis and is optimized through a response surface analysis. In the ultrasonic imprinting experiments, the response surface method was also used to determine the optimal processing conditions for better replication characteristics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.51-57
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• 2014

Ultrasonic imprinting is a novel process for replicating micropatterns on thermoplastic polymer substrates with low energy consumption and short cycle time. The polymer substrate is softened by the frictional heat and repetitive deformation energy under ultrasonic excitation; thus, a number of micropatterns are replicated on the softened polymer substrate. In the present work, the effect of mold temperature on the replication characteristics of ultrasonic imprinting is investigated. The temperature change in the patterned region is measured by varying the mold temperature. Numerical simulation is then performed for investigating pattern replication characteristics under various mold temperatures. In addition, pattern replication ratio and uniformity are compared through various experimental measurements. Through the results of these comparisons, it is found that the mold temperature has a significant positive effect on the replication characteristics of ultrasonic imprinting.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.302-309
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• 2008

Epigenetic is usually referring to heritable traits that do not involve changes to the underlying DNA sequence. DNA methylation is known to serve as cellular memory. and is one of the most important mechanism of epigenetic. DNA methylation is a covalent modification in which the target molecules for methylation in mammalian DNA are cytosine bases in CpG dinucleotides. The 5' position of cytosine is methylated in a reaction catalyzed by DNA methyltransferases; DNMTl, DNMT3a, and DNMT3b. There are two different regions in the context of DNA methylation: CpG poor regions and CpG islands. The intergenic and the intronic region is considered to be CpG poor, and CpG islands are discrete CpG-rich regions which are often found in promoter regions. Normally, CpG poor regions are usually methylated whereas CpG islands are generally hypomethylated. DNA methylation is involved in various biological processes such as tissue-specific gene expression, genomic imprinting, and X chromosome inactivation. In general. cancer cells are characterized by global genomic hypomethylation and focal hypermethylation of CpG islands, which are generally unmethylated in normal cells. Gene silencing by CpG hypermethylation at the promotors of tumor suppressor genes is probably the most common mechanism of tumor suppressor inactivation in cancer.

• Korean Journal of Poultry Science
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• v.41 no.3
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• pp.217-225
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• 2014

Telomeres are the ends of the eukaryotic chromosomes and consist of a tandem repetitive DNA sequence and shelterin protein complex. The function of telomere is to protect chromosome. Telomere length in somatic cells tends to decrease with organismal age due to the end replication problem. However, several factors at the genetic, epigenetic and environmental level affect telomere length. In this study, we estimated heritability of telomere length and investigated inheritance of telomeres in a chicken. Telomere length of lymphocytes was analyzed by semi-quantitative polymerase chain reaction using telomere primer and quantitative fluorescence in situ hybridization using telomeric DNA probe. In results, heritability of telomere length was estimated 0.9 at birth by offspring-parent regression analysis and was estimated 0.03 and 0.04 at 10 and 30 weeks old, respectively, by parental variance analysis. There was a significant positive correlation in telomere length between father and their offspring (r=0.348), and mother and their offspring (r=0.380). In inheritance patterns of telomere length, the influence of paternal and maternal effect on their offspring was similar. The influence of inherited telomeres on male and female progeny was also roughly alike. These results implicated that imprinting of parental telomere length was regulated by autosomal genes, not sex linked genes. In addition, telomere length of offspring at birth did not differ along with their maternal age. Thus, maternal age does not affects telomere length in their offspring at birth owing to cellular reprogramming at early embryonic stage.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.413-413
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• 2014

In this paper, we present a fabrication method of functionalized gold nanostructures on flexible substrate that can be implemented for plasmonic sensing application. For biomolecular sensing, many researchers exploit unconventional lithography method like nanoimprint lithography (NIP), contact transfer lithography, soft lithography, colloidal transfer printing due to its usability and easy to functionalization. In particular, nanoimprint and contact transfer lithography need to have anti-adhesion layer for distinctive metallic properties on the flexible substrates. However, when metallic thin film was deposited on the anti-adhesion layer coated substrates, we discover much aggravation of the mold by repetitive use. Thus it would be impossible to get a high quality of metal nanostructure on the transferred substrate for developing flexible electronics based transfer printing. Here we demonstrate a method for nano-pillar mold and transfer the controllable nanoparticle array on the flexible substrates without an anti-adhesion layer. Also functionalization of gold was investigated by the different length of thiol applied for effectively localized surface plasmonic resonance sensing. First, a focused ion beam (FIB) and ICP-RIE are used to fabricate the nanoscale pillar array. Then gold metal layer is deposited onto the patterned nanostructure. The metallic 130 nm and 250 nm nanodisk pattern are transferred onto flexible polymer substrate by bi-layer functionalized contact imprinting which can be tunable surface energy interfaces. Different thiol reagents such as Thioglycolic acid (98%), 3-Mercaptopropionic acid (99%), 11-Mercaptoundecanoic acid (95%) and 16-Mercaptohexadecanoic acid (90%) are used. Overcoming the repeatedly usage of the anti-adhesion layer mold which has less uniformity and not washable interface, contact printing method using bi-layer gold array are not only expedient access to fabrication but also have distinctive properties including anti-adhesion layer free, functionalized bottom of the gold nano disk, repeatedly replicate the pattern on the flexible substrate. As a result we demonstrate the feasibility of flexible plasmonic sensing interface and anticipate that the method can be extended to variable application including the portable bio sensor via mass production of stable nanostructure array and other nanophotonic application.