• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 춘계학술대회 논문요약집
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• pp.12-12
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• 2004

나노임프린트 관련되어 전 세계적으로 지금까지 4개회사가 장비 및 공정기술 개발을 하고 있으나 대부분 수년 전에 창업한 회사이며, 4개의 나노임프린트 장비 관련 회사는 미국의 Nanonex, 오스트리아의 EVG사, 미국의 Molecular Imprint Inc. (MII),스웨덴이 Obducat이다. 개발된 장비의 대부분은 수작업이 필요한 연구용 장비로 현재 공정 기술개발을 위해 활용되고 있으며, MI사 장비가 최초로 양산 적용을 목표로 개발하여 국내에도 도입 되어있다. 일본에서는 아직 장비 개발이 시도된 바 없으며 현재 관련 공정 기술개발을 하고 있다.(중략)

• Molecules and Cells
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• 제27권6호
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• pp.635-640
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• 2009

Testis-derived germline stem (GS) cells can undergo reprogramming to acquire multipotency when cultured under appropriate culture conditions. These multipotent GS (mGS) cells have been known to differ from GS cells in their DNA methylation pattern. In this study, we examined the DNA methylation status of the H19 imprinting control region (ICR) in multipotent adult germline stem (maGS) cells to elucidate how epigenetic imprints are altered by culture conditions. DNA methylation was analyzed by bisulfite sequencing PCR of established maGS cells cultured in the presence of glial cell line-derived neurotrophic factor (GDNF) alone or both GDNF and leukemia inhibitory factor (LIF). The results showed that the H19 ICR in maGS cells of both groups was hypermethylated and had an androgenetic pattern similar to that of GS cells. In line with these data, the relative abundance of the Igf2 mRNA transcript was two-fold higher and that of H19 was three fold lower than in control embryonic stem cells. The androgenetic DNA methylation pattern of the H19 ICR was maintained even after 54 passages. Furthermore, differentiating maGS cells from retinoic acid-treated embryoid bodies maintained the androgenetic imprinting pattern of the H19 ICR. Taken together these data suggest that our maGS cells are epigenetically stable for the H19 gene during in vitro modifications. Further studies on the epigenetic regulation and chromatin structure of maGS cells are therefore necessary before their full potential can be utilized in regenerative medicine.

• KSBB Journal
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• 제20권4호
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• pp.260-265
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• 2005

N-CBZ-L-phenylalanine를 주형분자로 하고 MAA와 4-VPY를 기능성 단량체로 하여 분자각인 고분자를 합성하였다. N-CBZ-L-phenylalanine와 MAA, 4-VPY는 수소결합의 영향을 많이 받고 있으며 이온결합과 소수성결합도 작용하고 있다. 혼합성분을 기능성 단량체로 사용함으로 하여 단량체의 성분들 사이에서 상호작용 효과를 나타냈다. 실험결과에 의하면 혼합 성분인 MAA와 4-VPY를 기능성 단량체로 한 분자각인 고분자에서의 체류인자가 단일성분인 MAA를 사용한 고분자에서의 체류인자보다 컸고 컬럼 효율은 낮았지만 분리도는 높았다. 산성인 MAA와 염기성인 4-VPY를 함께 사용함으로써 거울상 이성질체인 N-CBZ-L-phenylalanine과 N-CBZ-D- phenylalanine의 분리도를 증가시킬 수 있었다. 혼합된 성분의 기능성 단량체로하여 제조된 분자각인 고분자를 키랄 물질의 분리를 비롯한 천연물질의 분리에 더 광범위하게 사용될 수 있을 것이다.

• Journal of Genetic Medicine
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• 제15권2호
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• pp.64-71
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• 2018

Purpose: Overgrowth syndromes are conditions that involve generalized or localized areas of excess growth. In this study, the clinical, molecular, and genetic characteristics of Korean patients with overgrowth syndrome were analyzed. Materials and Methods: We recruited 13 patients who presented with overgrowth syndrome. All patients fulfilled inclusion criteria of overgrowth syndrome. Analysis of the clinical and molecular investigations of patients with overgrowth syndrome was performed retrospectively. Results: Among the 13 patients with overgrowth syndrome, 9 patients (69.2%) were found to have molecular and genetic causes. Among the seven patients with Sotos syndrome (SS), two had a 5q35microdeletion that was confirmed by fluorescent in situ hybridization. In two patients with SS, intragenic mutations including a novel mutation, c.5993T>A (p.M1998L), were found by Sanger sequencing. One patient had one copy deletion of NDS1 gene which was confirmed by multiplex ligation-dependent probe amplification. Among five patients with Beckwith-Wiedemann syndrome, three had aberrant imprinting control regions; 2 hypermethylation of the differentially methylated region of H19, 1 hypomethylation of the differentially methylated region of Kv. In one patient displaying overlapping clinical features of SS, a de novo heterozygous deletion in the chromosomal region 7q22.1-22.3 was found by single nucleotide polymorphism-based microarray. Conclusion: Considering high detection rate of molecular and genetic abnormalities in this study, rigorous investigations of overgrowth syndrome may be an important tool for the early diagnosis and genetic counseling. A detailed molecular analysis of the rearranged regions may supply the clues for the identification of genes involved in growth regulation.

• Asian-Australasian Journal of Animal Sciences
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• 제24권1호
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• pp.37-44
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• 2011

Parthenogenetic embryonic stem (pES) cells could provide a valuable model for research into genomic imprinting and X-linked diseases. In this study, pES cell lines were established from oocytes of hybrid offspring of Kunming and 129/Sv mice, and pluripotency of pES cells was evaluated. The pES cells maintained in the undifferentiated state for more than 50 passages had normal karyotypes with XX sex chromosomes and exhibited high activities of alkaline phosphatase (AKP) and telomerase. Meanwhile, these cells expressed ES cell molecular markers SSEA-1, Oct-4, Nanog, and GDF3 but not SSEA-3 detected by immunohistochemistry and RT-PCR. The pES cells could be differentiated into various types of cells from three germ layers in vitro by analysis of embryoid bodies (EBs) with immunohistochemistry and RT-PCR, and in vivo by observation of pES cell-derived teratoma sections. Therefore, the established pES cell lines contained all features of mouse ES cells. This work provides a new strategy for isolating pES cells from Kunming mice, and the pES cell lines could be applied as the cell model in research into genomic imprinting and epigenetic regulation of Kunming mice.

• Nano
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• 제13권11호
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• pp.1850131.1-1850131.19
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• 2018

In this paper, an electrochemical sensor for epinephrine (EP), a neurotransmitter was developed by anchoring molecularly imprinted polymeric matrix (MIP) on the surface of gold-coated quartz crystal electrode of electrochemical quartz crystal microbalance (EQCM) using starch nanoparticles (Starch NP) - reduced graphene oxide (RGO) nanocomposite as polymeric format for the first time. Use of EP in therapeutic treatment requires proper dose and route of administration. Proper follow-up of neurological disorders and timely diagnosis of them has been found to depend on EP level. The MIP sensor was developed by electrodeposition of starch NP-RGO composite on EQCM electrode in presence of template EP. As the imprinted sites are located on the surface, high specific surface area enables good accessibility and high binding affinity to template molecule. Differential pulse voltammetry (DPV) and piezoelectrogravimmetry were used for monitoring binding/release, rebinding of template to imprinted cavities. MIP-coated EQCM electrode were characterized by contact angle measurements, AFM images, piezoelectric responses including viscoelasticity of imprinted films, and other voltammetric measurements including direct (DPV) and indirect (using a redox probe) measurements. Selectivity was assessed by imprinting factor (IF) as high as 3.26 (DPV) and 3.88 (EQCM). Sensor was rigorously checked for selectivity in presence of other structurally close analogues, real matrix (blood plasma), reproducibility, repeatability, etc. Under optimized conditions, the EQCM-MIP sensor showed linear dynamic ranges ($1-10{\mu}M$). The limit of detection 40 ppb (DPV) and 290 ppb (EQCM) was achieved without any cross reactivity and matrix effect indicating high sensitivity and selectivity for EP. Hence, an eco-friendly MIP-sensor with high sensitivity and good selectivity was fabricated which could be applied in "real" matrices in a facile manner.

• KSBB Journal
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• 제14권3호
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• pp.273-278
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• 1999

The molecularly imprinted polymers(MIPs) synthesized at various polymerization conditions were examined as ibuprofen receptors in terms of binding characteristics. The 4-vinylpyridine polymers had 1.2 times higher adsorption capability for (S)-(+)-ibuprofen than the methacrylic acid polymers. The methacrylic acid polymers synthesized by UV radiation had 1.9 times higher selectivity for (S)-(+)-ibuprofen compared to those by thermal initiation. Effects of various solvents for binding were also examined in this research. According to the Scatchard analysis, the (S)-(+)-ibuprofen artificial receptors had two different kinds of binding sites for (S)-(+)-ibuprofen while having only single kind of binding site for ketoprofen. The binding sites of (S)-(+)-ibuprofen, n were calculated as 4.3~4.9 $\mu$mol/g and the dissociation constants, $K_D$ were 0.68 mM for the specific binding.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권3호
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• pp.133-139
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• 2007

Future MEMS systems will be composed of larger varieties of devices with very different functionality such as electronics, mechanics, optics and bio-chemistry. Integration technology of heterogeneous devices must be developed. This article first deals with the current development trend of new fabrication technologies; those include self-assembling of parts over a large area, wafer-scale encapsulation by wafer-bonding, nano imprinting, and roll-to-roll printing. In the latter half of the article, the concept towards the heterogeneous integration of devices and functionality into micro/nano systems is described. The key idea is to combine the conventional top-down technologies and the novel bottom-up technologies for building nano systems. A simple example is the carbon nano tube interconnection that is grown in the via-hole of a VLSI chip. In the laboratory level, the position-specific self-assembly of nano parts on a DNA template was demonstrated through hybridization of probe DNA segments attached to the parts. Also, bio molecular motors were incorporated in a micro fluidic system and utilized as a nano actuator for transporting objects in the channel.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.71-71
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• 2003

Hot embossing has been widely accepted as an alternative to photolithography in generating patterns on polymeric substrates. The optimization of embossing process should be accomplished based on polymer substrate materials. In this paper, the effect of polymer substrates on nano scale hot embossing process was studied. Silicon molds with nano size patterns were fabricated by e-beam direct writing. Molds were coated with self-assembled monolayer (SAM) of (1, 1, 2.2H -perfluorooctyl)-trichlorosilane to reduce the stiction between mold and substrates. For an embossing, pressure of 55, 75 bur, embossing time of 5 min and temperature of above transition temperature were peformed. Polymethylmethacrylates (PMMA) with different molecular weights of 450,000 and 950,000, MR-I 8010 polymer (Micro Resist Technology) and polyaliphatic imide copolymer were applied for hot embossing process development in nano size. These polymers were spun coated on the Si wafer with the thickness between 150 and 200 nm. The nano size patterns obtained after hot embossing were observed and compared based on the polymer properties by scanning electron microscopy (SEM). The imprinting uniformity dependent on the Pattern density and size was investigated. Four polymers have been evaluated for the nanoimprint By optimizing the process parameters, the four polymers lead to uniform imprint and good pattern profiles. A reduction in the friction for smooth surfaces during demoulding is possible by polymer selection.

• 폴리머
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• 제37권3호
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• pp.288-293
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• 2013

A group of molecularly imprinted polymers (MIPs) with specific recognition for chiral (S)-ibuprofen were successfully prepared based on hydrogen bonds, utilizing ${\alpha}$-methacrylic acid as a functional monomer. The IR analysis of MIPs showed that the blue- and red-shifted hydrogen bonds were formed between templates and functional monomers in the process of self-assembly imprinting and re-recognition, respectively. According to UV-Vis analysis, we found that the ratio of host-guest complexes between template molecule and functional monomer was 1:1. The effect of cross-linker's quantity on the polymerization was studied by transmission electron microscope (TEM). The adsorption selectivity experiments indicated that MIPs exhibited higher selectivity to (S)-ibuprofen than those to ketoprofen and (R)-ibuprofen, (S)-ibuprofen's structural analogs.