• 제목/요약/키워드: Contrast phase

검색결과 840건 처리시간 0.027초

Effectiveness of a Turbo Direction Change for Reduction of Motion Artifact in Magnetic Resonance Enterography

  • Choi, Kwan-Woo;Son, Soon-Yong;Jeong, Mi-Ae
    • Journal of Magnetics
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    • 제21권3호
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    • pp.421-424
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    • 2016
  • The purpose of this study is to evaluate an effectiveness of switching turbo direction to improve motion artifacts of small bowels and aorta. From June to October 2015, 60 patients suspected of having Crohn's disease were enrolled. The MR Enterography scans were performed using same protocol other than the turbo direction: with the Z phase encoding (group A) and with Y phase encoding (group B). Qualitative analysis of each group was performed to evaluate the effectiveness of switching turbo direction from Z to Y. As a result, the 5-point Likert scale for paired observers were $2.33{\pm}0.88$ for group A and $3.80{\pm}0.85$ for group B on dynamic contrast enhanced coronal images. In conclusion, group B is proved to be superior to group A and can lessen the motion artifacts derived from phase shifts.

Applications of Digital Holography in Biomedical Microscopy

  • Kim, Myung-K.
    • Journal of the Optical Society of Korea
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    • 제14권2호
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    • pp.77-89
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    • 2010
  • Digital holography (DH) is a potentially disruptive new technology for many areas of imaging science, especially in microscopy and metrology. DH offers a number of significant advantages such as the ability to acquire holograms rapidly, availability of complete amplitude and phase information of the optical field, and versatility of the interferometric and image processing techniques. This article provides a review of the digital holography, with an emphasis on its applications in biomedical microscopy. The quantitative phase microscopy by DH is described including some of the special techniques such as optical phase unwrapping and holography of total internal reflection. Tomographic imaging by digital interference holography (DIH) and related methods is described, as well as its applications in ophthalmic imaging and in biometry. Holographic manipulation and monitoring of cells and cellular components is another exciting new area of research. We discuss some of the current issues, trends, and potentials.

Inverter 방식(方式) X선장치(X線裝置)의 임상응용(臨床應用) (Clinical Application of Inverter type X-ray Generator)

  • 이선숙;허준;이재원;김정민
    • 대한방사선기술학회지:방사선기술과학
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    • 제15권1호
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    • pp.107-113
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    • 1992
  • Inverter type X-ray apparatus has been introduced and used several hospitals. Principle of inverter type X-ray generators are such as to convert the frequency of commercial power supply to high frequency and to control the high voltages for X-ray tube. Inverter generators are now on the way for futher development to elliminate single phase generators and three phase generators. We compared inverter type X-ray apparatus with conventional single phase 2 peak and three phase 12 peak, apparatus in the following aspects X-ray out put to tube voltage, linearity of X-ray out put to mA, HVL according to mA contrast to kV.

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Electrical Phase Transition of Poly (4,4'-Aminotriphenylene Hexafluoroisopropylidenediphthalimide) by Photogenerated Charged Carrier Injection

  • 임규욱;이경재;이문호;강태희;정석민;양미현
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.266-266
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    • 2013
  • We show a set-up of poly (4,4'-aminotriphenylene hexafluoroisopropylidenediphthalimide) (6F-TPA PI)/Al sample in which holes are injected by photoelectron emission process instead of direct charge carrier injection via metal electrode. In this process, an irreversible electrical phase transition of 6F-TPA PI is found in contrast to the Al/6F-TPA PI/Al structure, leading to a write-once-readmany behavior. The photoelectron spectroscopy results measured before and after the switching process revealed that the irreversible electrical phase transition of 6F-TPA PI is attributed to the chemical modification of the carbonyl group in phthalimide moiety.

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실험 렌즈의 광량과 해상력 측정 (A Study on the Measurement of Quantity of Light and Resolving Power of a Hand-made Lens)

  • 강현덕
    • 한국인쇄학회지
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    • 제14권1호
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    • pp.89-114
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    • 1996
  • Liquid crystal-polymer composite(LCPC) films consisting of a continuous LC phase embedded in a three-dimensional network of polymer matrix are formed by photopolymerization-induced phase separ on. The LCPC films are switched from a light-scattering stats to a highly transparent stats on the application of electric fields. Since the alignment of LC molecular determines the electro-optical properties of films, the requirement for good contrast is to generate the nematic phase at high concentration. On the other hand, the concentration of UV-curable monomer must be increased above some critical value to from the flexible matrix of unbounded polymer. The mixing ratio of LC and UV-curable monomer affects the electro-optical and viscoelastic properties of LCPD films in two opposing ways. By controlling the phase separation process, at an LC fraction of 0.7, the maximum performance of LCPC films has been achieved, the response time of which is 2ms on the application of electric fields.

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Bi 초전도 박막의 부착계수 해석 (Analysis of Sticking Coefficient in Bi-Superconducting Thin film)

  • 천민우;박용필;이성일
    • 한국전기전자재료학회논문지
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    • 제15권11호
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    • pp.997-1002
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    • 2002
  • BSCCO thin films are fabricated by an ion beam sputtering method, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element in BSCCO film formation was observed to show a unique temperature dependence; it was almost a constant value of 0.49 below about 730$^{\circ}C$ and decreased linearly over about 730$^{\circ}C$ In contrast, Sr and Ca, displayed no such remarkable temperature dependence. This behavior of the sticking coefficient was explained consistently on the basis of the evaporation and sublimation processes of Bi$\sub$2/O$\sub$3/. It was concluded that Bi(2212) thin film constructs from the partial melted Bi(2201) phase with the aid of the liquid phase of Bi$\sub$2/O$\sub$3/.

Contribution of lysine-containing cationic domains to thermally-induced phase transition of elastin-like proteins and their sensitivity to different stimuli

  • Jeon, Won-Bae
    • BMB Reports
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    • 제44권1호
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    • pp.22-27
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    • 2011
  • A series of elastin-like proteins, $SKGPG[V(VKG)_3VKVPG]_n$-(ELP1-90)WP (n = 1, 2, 3, and 4), were biosynthesized based on the hydrophobic and lysine linkage domains of tropoelastin. The formation of self-assembled hydrophobic aggregates was monitored in order to determine the influence of cationic segments on phase transition properties as well as the sensitivity to changes in salt and pH. The thermal transition profiles of the proteins fused with only one or two cationic blocks (n = 1 or 2) were similar to that of the counterpart ELP1-90. In contrast, diblock proteins that contain 3 and 4 cationic blocks displayed a triphasic profile and no transition, respectively. Upon increasing the salt concentration and pH, a stimulus-induced phase transition from a soluble conformation to an insoluble aggregate was observed. The effects of cationic segments on the stimuli sensitivity of cationic bimodal ELPs were interpreted in terms of their structural and molecular characteristics.

Image Findings of Sarcomatous Intrahepatic Cholangiocarcinoma Focused on Gd-EOB-DTPA Enhanced MRI: A Case Report

  • Kim, Ki Beom;Kim, Seong Hoon
    • Investigative Magnetic Resonance Imaging
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    • 제19권1호
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    • pp.47-51
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    • 2015
  • Sarcomatous Intrahepatic cholangiocarcinoma is a rare but an aggressive variant of cholangiocarcinoma with a very poor prognosis. A 79-year-old man was admitted to our hospital because of incidentally found liver mass. Magnetic resonance imaging (MRI) revealed well-defined hypointense mass on T1WI and heterogeneous hyperintense mass on T2WI. Gd-EOB-DTPA enhanced study shows peripheral rim-like enhancement in arterial phase and progressive concentric filling of contrast in delayed phase. And mass shows significant enhancement in hepatobiliary phase. The pathologic diagnosis was intrahepatic cholangiocarcinoma with sarcomatous change.

BSCCO 박막의 부착계수 해석 (Analysis of Sticking Coefficient in BSCCO Thin Film)

  • 천민우;박용필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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    • pp.252-255
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    • 2002
  • BSCCO thin films are fabricated by an ion beam sputtering method, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element in BSCCO film formation was observed to show a unique temperature dependence; it was almost a constant value of 0.49 below about $730^{\circ}C$ and decreased linearly over about $730^{\circ}C$. In contrast, Sr and Ca, displayed no such remarkable temperature dependence. This behavior of the sticking coefficient was explained consistently on the basis of the evaporation and sublimation processes of $Bi_{2}O_{3}$. It was concluded that Bi(2212) thin film constructs from the partial melted Bi(2201) phase with the aid of the liquid phase of $Bi_{2}O_{3}$.

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PRAM용 GST계 상변화 박막의 하부막에 따른 특성 (Properties of GST Thin Films for PRAM with Bottom Electrode)

  • 장낙원;김홍승
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.205-206
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    • 2005
  • PRAM (Phase change Random Access Memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change material has been researched in the field of optical data storage media. Among the phase change materials, $Ge_2Sb_2Te_5$(GST) is very well known for its high optical contrast in the state of amorphous and crystalline. However, the characteristics required in solid state memory are quite different from optical ones. In this study, the structural properties of GST thin films with bottom electrode were investigated for PRAM. The 100-nm thick GST films were deposited on TiN/Si and TiAlN/Si substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films, we performed x-ray diffraction (XRD) and atomic force microscopy (AFM).

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