• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.553-553
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• 2012

The artificial shells of hard inorganic nanocomposites on individual cells would protect the cells physically and chemically, and control cell division. These emerging properties could be combined with cell-surface functionalizations for applications to cell-based sensors and assays as well as for fundamental studies on single-cell biology. In this work, individual Chlorella cells were encapsulated within a silica/titania nanocomposite shell in a biocompatible fashion that utilized a designed peptide, RKKRKKRKKRKKDDDDDDDD, as a catalytic template for formation of both $SiO_2$ and $TiO_2$ on the cell surface. The cell viability was maintained, and the division of the encapsulated Chlorella cells was controlled. The cell viability was enhanced compared with the $TiO_2$-shell formation. In addition, the incorporation of $TiO_2$ to the shell made it possible to anchor the ligands of interest to the shell via catechol chemistry. All in all, the combination of biological $SiO_2$ and abiolgical $TiO_2$ for the shell formation gave more tunability of the artificial shells compared with the $SiO_2$ or $TiO_2$ shells only.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2689-2693
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• 2012

Single-walled carbon nanotubes (SWNTs) and $C_{60}$-encapsulated SWNTs ($C_{60}@SWNTs$) are introduced to Ru-sensitized photoelectrochemical cells (PECs), and photocurrents are compared between two cells, i.e., an $RuL_2(NCS)_2$/DAPV/SWNTs/ITO cell and an $RuL_2(NCS)_2$/DAPV/$C_{60}@SWNTs$/ITO cell. [L = 2,2'-bipyridine-4,4'-dicarboxylic acid, DAPV = di-(3-aminopropyl)-viologen, and ITO = indium-tin oxide] The photocurrents are increased by 70.6% in the presence of $C_{60}@SWNTs$. To explain the photocurrent increase, the reverse-field emission method is used, i.e., $RuL_2(NCS)_2$/DAPV/SWNTs/ITO cell (or $RuL_2(NCS)_2$/DAPV/$C_{60}@SWNTs$/ITO cell) as an anode and a counter electrode Pt as a cathode in the external electric field. The improved field emission properties, i.e., ${\beta}$ (field enhancement factor) and emission currents in the reverse-field emission with $C_{60}@SWNTs$ indicate the enhancement of the PEC electric field, which implies the improvement of the electron transfer rate along with the reduced charge recombination in the cell.

• 대한방사선기술학회지:방사선기술과학
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• 제29권3호
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• pp.147-155
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• 2006

기체 저장제로서 제올라이트의 구조와 기체분자의 유출입 기전을 이해하기 위해 완전히 탈수된 $K_3-A$들을 제조하고 $K_3Na_8H-A(R_1=0.0478,\;R_2=0.0458$ 및 $a=12.257(1){\AA}$)의 결정구조들을 Pm3m 입방 공간군에서 단결정 X-ray 회절 방법으로 연구하였다. 진공 탈수된 $K_3Na_8H-A$의 결정구조에 있어서, 단위세포 당 3개의 $K^+$ 이온들이 8-ring(0.0, 0.4531, 0.4531) 상에 존재하였고, 단위세포 당 8개의 $Na^+$ 이온들이 6-oxygen ring들의 중앙에 위치하였다. 8-ring상에 존재하는 각 $K^+$ 이온들은 두 가지 종류의 골격산소 원자들로 부터 각각 $2.87(2){\AA}$과 $2.79(1){\AA}$의 거리를 가지고 있었다. 이러한 값들은 이미 기존에 알려진 $K_{12}Na-A$의 값들보다 더 짧은 값으로 이들의 이온 반경들을 고려할 때 더 타당한 값들이였다. $K^+$ 이온들의 정확한 위치들은 8-ring들의 중앙으로부터 약 $0.8{\AA}$ 떨어져 있었다. 이러한 결과는 제올라이트 골격을 안전화시켜 기체분자들의 효과적인 유출입 통제와 저장을 가능하게 하며, 유효 부피 극대화를 이루어 더 많은 기체 저장을 할 수 있으므로 병원에서 사용하는 산소 저장 용기를 더욱더 소형임은 물론 산소가 필요한 응급환자 들을 위한 휴대하기 간편한 용기를 만들어 줄 것으로 예상된다.

• 폴리머
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• 제29권6호
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• pp.613-616
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• 2005

본 연구에서는 한 개의 세포와 같은 미세한 생체시료 내부의 분석 대상물질을 감지하는데 사용할 수 있는 광바이오센서를 개발하기 위한 첫 단계로서 효소가 함유된 고분자 수화젤 구형입자를 나노크기로 중합하는 방법을 확립하고 센서로서의 사용 가능성을 확인하였다. 현탁 광중합을 통하여 305 nm의 평균크기를 가지는 horseradish peroxidase(HRP)가 함유된poly(ethylene glycol)(PEG) 수화젤 구형입자를 합성하였으며, 중합반응 이후 입자내부의 효소의 존재 및 활성유지를 HRP와$\H_{2}O_{2}$의 효소반응에 의한 Amplex Red의 형광산화물 생성을 통하여 확인하였다. 합성된 HRP가 함유된 PEG 수화젤 입자는 Amplex Red의 존재하에 $\H_{2}O_{2}$의 농도가 0에서 11 nM로 미량 변화함에 따라서 형광세기가 약 300$\%$ 증가함을 보여 주었다. 이러한 결과는 효소가 함유된 PEG 수화젤 나노입자를 합성하는 본 기술이 향후 미세한 생체시료 내부의 다양한 분석대상물질을 감지할 수 있는 나노크기의 광바이오센서를 개발하는데 이용 될 수 있는 가능성을 보여준다.

• 분석과학
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• 제15권6호
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• pp.540-549
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• 2002

The arrangement of encapsulated Ar atoms in the molecular-dimensioned cavities of fully dehydrated zeolite A of unit-cell composition $Cs_3Na_8HSi_{12}Al_{12}O_{48}$ ($Cs_3$-A) has been studied crystallographically to probe the confinement effect of guest species in microporous environment. Atoms of Ar were encapsulated in the cavities of $Cs_3$-A by treatment with 410 atm of Ar at $400^{\circ}C$ for two days, followed by cooling at room temperature. The crystal structure of $Cs_3Na_8H$-A(4Ar) ($P_e$ = 410 atm, $a=12.245(2){\AA}$, $R_1=0.0543$, and $R_2=0.0552$) has been determined by single crystal X-ray diffraction technique in the cubic space group $Pm\bar{3}m$ at 21 (1) $^{\circ}C$ and 1 atm. Encapsulated Ar atoms are distributed in three crystallographic distinct positions: 1.5 Ar atoms per unit cell opposite 6-rings, 1.5 opposite four-rings in the large cavity, and finally 1.0 in the sodalite-unit. The possible structures of argon clusters, such as $Ar_2$, $Ar_3$, and $Ar_4$, are proposed.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제12권3호
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• pp.34-41
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• 1990

The pilomatricoma (calcifying epithelioma of Malherbe) is rare benign hard, spherical and freely movable cutaneous tumor, which was differentiated from hair cells, particulary hair cortex cells. It is usually occured as a single, asymptomatic, 0.5 cm to 3.0 cm sized, deep seated, firm nodule, covered by normal or pink skin. It arises chiefly in young people, including children, and most often in the head, neck and upper extrimites. The authers experienced a case of pilomatricoma which occured in preauricular region. This case was summarized as follows. 1. 10 years old female has suffered from hard subepidermal mass on preauricular area and she visited our out patient clinic. So we performed surgical extirpation and the excised specimen was pathologically examined. 2. Grossly the tumor measures 2.0 cm in diameter and firm, bosselated, spherical shaped which covered by a thin layer of fibrous tissue. On cut section, it shows spicular gritty surfaces, well encapsulation, interwoven and keratotic lamellae. 3. Histopathologically, the epithelial masses of the tumor are composed of two type of cells, basophilic cells and shodow cells. The basophilic cells resemble hair matrix cells which posses round or elogated, deeply basophilic nuclei and scanty cytoplasm. The shadow cells show a central, unstained shadow at the site of the lost nucleus. Gradual development of basophilic cells into shadow cells can be observed. Foci of calcification are present within the lobule of shadow cells. The stroma of the tumor shows a considerable foreign body giant cell reaction adjacent to the shadow cells. 4. No recurrence was observed until post-operative 40 months.

• Bulletin of the Korean Chemical Society
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• 제16권10호
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• pp.923-929
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• 1995

Four crystal structures of M3-A (M3Na9-xHx-A, M=Rb or K and x=1 or 0), Rb3Na8H-A(a=12.228(1) Å and R1=0.046), Rb3Na9-A (a=12.258(3) Å and R1=0.058), K3Na8H-A (a=12.257(3) Å and R1=0.048) and K3Na9-A (a=12.257(3) Å and R1=0.052), have been determined by single crystal x-ray diffraction technique in the cubic space group Pm3^m at 21 ℃. In all structures, each unit cell contained three M+ ions all located at one crystallographically distinct position on 8-rings. Rb+ ions are 3.12 and 3.21 Å away respectively from O(1) and O(2) oxygens, about 0.40 Å away from the centers of the 8-rings, and K+ ions are 2.87 and 2.81 Å apart from the corresponding oxygens. These distances are the shortest ones among those previously found for the corresoponding ones. Eight 6-rings per unit cell are occupied by eight Na+ ions, each with a distance of 2.31 Å to three O(3) oxygens. The twelfth cation per unit cell is found as Na+ opposite 4-ring in the large cavities of M3Na9-A and assumed to be H+ for M3Na8H-A. With these noble non-framework cationic arrangements, larger M+ ions preferably on all larger 8-rings and the compact Na+ ions on all 6-rings, the bond angles in the 8-rings of M3-A, 145.1 and 161.0 respectively for (Si,Al)-O(1)-(Si,Al) and (Si,Al)-O(2)-(Si,Al), turned out to be remarkably stable and smaller, by more than 12 to 17°, than the corresponding angles found in the crystal structures of zeolites A with high concentration of M+ ions. It is to achieve these remarkably relaxed 8-rings, the main windows for the passage of gas molecules, with simultaneously maximized cavity volumes that M3-A have been selected as one of the efficient zeolite A systems for gas encapsulation.