• Title/Summary/Keyword: 3A

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Synthesis and Luminescent Properties of Blue Light Emitting Polymers Containing a 4,4' or 3,3'-Linked Biphenyl Unit

  • Ahn, Taek
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.6
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    • pp.317-321
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    • 2012
  • Poly[4,4'(3,3')-biphenylenevinylene-alt-2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-vinylene], 4,4'(3,3')-PBPMEH-PPV, and poly[4,4'(3,3')-biphenylenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene], 4,4'(3,3')-PBPCAR-PPV, of varying effective conjugation lengths, were synthesized by the well-known Wittig condensation polymerization between the appropriate biphenyl diphosphonium salts and dialdehyde monomers such as carbazole or dialkoxyphenyl dialdehyde. The conjugation lengths of the polymers were controlled by biphenyl linkages (4,4' or 3,3'). The resulting polymers were highly soluble in common organic solvents and exhibited good thermal stability up to $300^{\circ}C$. The synthesized polymers showed UV-visible absorbance and photoluminescence (PL) in the ranges of 314-400 nm and 430-507 nm, respectively. Carbazole and 3,3'-biphenyl containing 3,3'-PBPCAR-PPV showed a blue PL peak at 430 nm. A single-layer light-emitting diode was fabricated in a configuration of ITO/polymer/Al. Electroluminescence (EL) emission of 3,3'-PBPCAR-PPV was shown at 455 nm.

3D Face Modeling based on 3D Morphable Shape Model (3D 변형가능 형상 모델 기반 3D 얼굴 모델링)

  • Jang, Yong-Suk;Kim, Boo-Gyoun;Cho, Seong-Won;Chung, Sun-Tae
    • The Journal of the Korea Contents Association
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    • v.8 no.1
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    • pp.212-227
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    • 2008
  • Since 3D face can be rotated freely in 3D space and illumination effects can be modeled properly, 3D face modeling Is more precise and realistic in face pose, illumination, and expression than 2D face modeling. Thus, 3D modeling is necessitated much in face recognition, game, avatar, and etc. In this paper, we propose a 3D face modeling method based on 3D morphable shape modeling. The proposed 3D modeling method first constructs a 3D morphable shape model out of 3D face scan data obtained using a 3D scanner Next, the proposed method extracts and matches feature points of the face from 2D image sequence containing a face to be modeled, and then estimates 3D vertex coordinates of the feature points using a factorization based SfM technique. Then, the proposed method obtains a 3D shape model of the face to be modeled by fitting the 3D vertices to the constructed 3D morphable shape model. Also, the proposed method makes a cylindrical texture map using 2D face image sequence. Finally, the proposed method builds a 3D face model by rendering the 3D face shape model with the cylindrical texture map. Through building processes of 3D face model by the proposed method, it is shown that the proposed method is relatively easy, fast and precise than the previous 3D face model methods.

Cell transformation of bisphenol A in Syrian hamster embryo cells and mouse embryo BalB/c 3T3 cells (Syrian hamster embryo 세포와 mouse embryo BalB/c 3T3 세포에서의 bisphenol A의 세포 형질전환 연구)

  • 김종원;한의식;박미선;엄미옥;전혜승;민수진;김인숙;정해관;심웅섭
    • Environmental Mutagens and Carcinogens
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    • v.21 no.1
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    • pp.44-50
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    • 2001
  • To identify nongenotoxic carcinogen determined as negative by ICH guideline-recommended standard genotoxicity test battery; Ames test, chromosome aberration assay, mouse lymphoma $tk^{+/-}$ assay, in vivo micronucleus assay, we picked bisphenol A as a model compound. In this study, we applied in vitro BalB/c 3T3 cell transformation assay and Syrian hamster embryo (SHE) cell transfarmation assay. Bisphenol A was treated upto $769.2 ug/m{\ell}$ in BalB/c 3T3 cells and upto $125 ug/m{\ell}$ in SHE cells. bisphenol A didn't induced morphological transformation both with one stage treatment protocol and with two stage treatment protocol. But, treated far 48 hr, Bisphenol A induced morphological transformation significantly in SHE cells.

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Analysis of Geometric and Spatial Image Quality of KOMPSAT-3A Imagery in Comparison with KOMPSAT-3 Imagery

  • Erdenebaatar, Nyamjargal;Kim, Jaein;Kim, Taejung
    • Korean Journal of Remote Sensing
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    • v.33 no.1
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    • pp.1-13
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    • 2017
  • This study investigates the geometric and spatial image quality analysis of KOMPSAT-3A stereo pair. KOMPSAT-3A is, the latest satellite of KOMPSAT family, a Korean earth observation satellite operating in optical bands. A KOMPSAT-3A stereo pair was taken on 23 November, 2015 with 0.55 m ground sampling distance over Terrassa area of Spain. The convergence angle of KOMPSAT-3A stereo pair was estimated as $58.68^{\circ}$. The investigation was assessed through the evaluation of the geopositioning analysis, image quality estimation and the accuracy of automatic Digital Surface Model (DSM) generation and compared with those of KOMPSAT-3 stereo pair with the convergence angle of $44.80^{\circ}$ over the same area. First, geopositioning accuracy was tested with initial rational polynomial coefficients (RPCs) and after compensating the biases of the initial RPCs by manually collected ground control points. Then, regarding image quality, relative edge response was estimated for manually selected points visible from two stereo pairs. Both of the initial and bias-compensated positioning accuracy and the quality assessment result expressed that KOMPSAT-3A images showed higher performance than those of KOMPSAT-3 images. Finally, the accuracy of DSMs generated from KOMPSAT-3A and KOMPSAT-3 stereo pairs were examined with respect to the reference LiDAR-derived DSM. The various DSMs were generated over the whole coverage of individual stereo pairs with different grid spacing and over three types of terrain; flat, mountainous and urban area. Root mean square errors of DSM from KOMPSAT-3A pair were larger than those for KOMPSAT-3. This seems due to larger convergence angle of the KOMPSAT-3A stereo pair.

1.3μm Waveband Al2O3/a-Si Thin-Film Etalon and Measurements of Optical Constants (1.3μm 파장 Al2O3/a-Si 박막 에탈론과 광학 상수 측정)

  • Song, H.W.;Kim, J.H.;Han, W.S.
    • Korean Journal of Optics and Photonics
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    • v.16 no.5
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    • pp.476-478
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    • 2005
  • We have fabricated a Fabry-Perot etalon around $1.3\;{\mu}m$ wavelength utilizing $Al_{2}O_3$ and a-Si thin films. A full width at half maximum of ${\sim}12.1nm$ and a finesse value of 53 were found from the measured resonant transmission spectra. Single thin film of $Al_{2}O_3$ was analyzed by spectroscopic ellipsometry. A refractive index of a-Si thin film was measured as 3.120 in the real part and 0.002 in the imaginary part, respectively. The thin-film pairs of $Al_{2}O_3$ and a-Si are applicable to output mirrors of vertical-cavity surface-emitting lasers at $1.3{\mu}m$ waveband.

Development of a Custom-Made Dress Form for Draping Based on 3D Handheld Scanners and 3D Printing Technology (3D 핸디형 스캐너와 3D 프린팅 기술 기반 드레이핑용 커스텀 메이드 드레스폼 개발)

  • Ryu, Eun Joo;Song, Hwa Kyung
    • Fashion & Textile Research Journal
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    • v.24 no.4
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    • pp.451-459
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    • 2022
  • This study aimed to develop a a custom-made dress form for draping using a live model's 3D body scan obtained from an entry-level 3D handheld scanners, 3D modeling software and 3D printing technology. A female subject was recruited whose body size fell under the normal (N) body shape criteria suggested by KS K 0051. First, the handheld scanner reduced the length of the legs in scanning, but most of the scanning operations between the neck and crotch levels were conducted accurately. Therefore, this study was designed to develop a torso dress form. The full body 3D scan was edited into a torso shape using ZBrush® software. Using Rhinoceros® and Materialise's Magics software, a 3D body scan was modeled so that the user could fit two types of mannequin stands (one with a neck fixation from above and one with an insert from below) to the dress form. The body scan was divided into 9 pieces to fit the printable size of the Stratasys 3D printer Fortus 250mc, and the cross-sectional distance from the center to the periphery was downsized by 2 mm. After outputting the dress form scan file with a 3D printer, the dress form was manufactured by the first covering it with a 4 oz nonwoven pad and the second covering with a single jersey material.

Trichostatin A, a Histone Deacetylase Inhibitor Stimulate CYP3A4 Proximal Promoter Activity in Hepa-I Cells

  • Ahn Mee Ryung;Kim Dae-Kee;Sheen Yhun Yhong
    • Archives of Pharmacal Research
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    • v.27 no.4
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    • pp.415-421
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    • 2004
  • Cytochrome P450 3A4 (CYP3A4) is the most abundant CYPs in human liver, comprising approximately $30\%$ of the total liver CYPs contents and is involved in the metabolism of more than $60\%$ of currently used therapeutic drugs. However, the molecular mechanisms underly-ing regulation of CYP3A4 gene expression have not been understood. Thus, this study has been carried out to gain the insight of the molecular mechanism of CYP3A4 gene expression, investigating if the histone deacetylation is involved in the regulation of CYP3A4 gene expression by proximal promoter. Also SXR was investigated to see if they were involved in the regulation of CYP3A4 proximal promoter activity. Hepa-1 cells were transfected with a plasmid containing ${\~}1kb$ of the human CYP3A4 proximal promoter region (863 to +64 bp) cloned in front of a reporter gene, luciferase, in the presence or absence of SXR. Transfected cells were treated with CYP3A4 inducers such as rifampicin, PCN and RU 486, in order to examine the regulation of CYP3A4 gene expression in the presence or absence of trichostatin A (TSA). In Hepa-1 cells, CYP3A4 inducers increased modestly the luciferase activity when TSA was co-treated, but this increment was not enhanced by SXR cotransfection. Taken together, these results indicated that the inhibition of histone deacetylation was required to SXR-mediated increase in CYP3A4 proximal promoter region when rifampicin, or PCN was treated. Further a trans-activation by SXR may demand other species-specific transcription factors.

Fabrication of Micro-reactor by 3D Printing Machine (3D 프린터를 이용한 마이크로 리액터 가공에 관한 연구)

  • Choi, Hae Woon;Yoon, Sung Chul;Ma, Jae Kwon;Bang, Dae Wook
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.3
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    • pp.218-222
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    • 2014
  • A 3D printer was used to fabricate a micro-TAS system for biomedical applications. A polymeric medical device fabrication based on a 3D printer can be performed at atmospheric conditions. A CAD- and CAM-based system is a flexible method to design medical components, and a 3D printer is a suitable device to perform this task. In this research, a 100-micron-wide fluidic channel was fabricated with a high-aspect ratio. A cross-sectional SEM image confirmed its possible usage in a micro-reactor using 3D printers. CNC-machined samples were compared to 3D printer-fabricated samples, and the advantages and disadvantages were discussed. Based on the SEM images, the surface roughness of the 3D printed reactor was not affected by wet or dry conditions due to its manufacturing principle. An aspect ratio of 5 to 1 was achievable with 100-${\mu}$ m-wide fluid channels. No melting was found, and the shape of channels was straight enough to be used for micro reactors.

A Fault Injection Attack on Stream Cipher A5/3 (스트림 암호 A5/3에 대한 오류 주입 공격)

  • Jeong, Ki-Tae;Lee, Yu-Seop;Sung, Jae-Chul;Hong, Seok-Hie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.1
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    • pp.3-10
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    • 2012
  • In this paper, we propose a fault injection attack on stream cipher A5/3 used in GSM. The fault assumption of this attack is based on that of fault injection attacks proposed in FDTC'05 and CISC-W'10. This attack is applicable to A5/3 supporting 64/128-bit session key, respectively, and can recover the session key by using a small number of fault injections. These works are the first known key recovery attack results on A5/3.

Potential Effects of Microglial Activation Induced by Ginsenoside Rg3 in Rat Primary Culture: Enhancement of Type A Macrophage Scavenger Receptor Expression

  • Joo, Seong-Soo;Lee, Do-Ik
    • Archives of Pharmacal Research
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    • v.28 no.10
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    • pp.1164-1169
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    • 2005
  • Brain microglia are phagocytic cells that are the major inflammatory response cells of the central nervous system and widely held to play important pathophysiologic roles in Alzheimer's disease (AD) in both potentially neurotoxic responses and potentially beneficial phagocytic responses. In the study, we examined whether ginsonoside Rg3, a by-product of red ginseng, enhances the microglial phagocytosis of $A{\beta}$. We found that Rg3 promoted $A{\beta}$ uptake, internalization, and digestion. Increased maximal $A{\beta}$ uptake was observed at 4 and 8 h after Rg3 pretreatment (25 ${\mu}g/mL$), and the internalized $A{\beta}$ was almost completely digested from cells within 36 h when pretreated with Rg3 comparing with single non-Rg3-treated groups. The expression of MSRA (type A MSR) was also up-regulated by Rg3 treatment in a dose- and time-dependent manner which was coincidently identified in western blots for MSRA proteins in cytosol. These results indicate that microglial phagocytosis of $A{\beta}$ may be enhanced by Rg3 and the effect of Rg3 on promoting clearance of $A{\beta}$ may be related to the MSRA-associated action of Rg3. Thus, stimulation of the MSRA might contribute to the therapeutic potentials of Rg3 in microglial phagocytosis and digestion in the treatment of AD.