• 제목/요약/키워드: photobleaching

검색결과 49건 처리시간 0.035초

포토폴리머의 광화학 표백 특성 (Photochemical bleaching properties of photopolymer)

  • 성기영;경천수;이영락;곽종훈;최옥식;이윤우;이인원;서호형
    • 한국광학회지
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    • 제10권4호
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    • pp.335-341
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    • 1999
  • 홀로그램 기록 매질로 acrylamide를 기초한 포토폴리머를 제작하고 광화학 표백 특성을 측정하였다. 포토폴리머의 광화학 표백 특성을 설명하기 위해 잘 알려진 Beer-Lambert 모델과 간단한 에너지 qosem 모델로부터 얻어진 율방정식에 기초한 광표백 모델에 관한 이론들을 유도하였다. 본 연구에 사용된 포토폴리머에 대해 Beer-Lambert 모델은 짧은 시간 영역에 대해서만 실험 결과와 일치하였으나 율방정식에 기초한 이론적인 광표백 모델은 짧고 긴 시간 영역 모두에 대해서 실험 결과와 잘 일치하였다.

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버어리종담배 대말림시 백화엽발생방지 및 건조기간단축에 관한 연구 (Studies on the Method of Reducing of the Photobleaching Leaves and Shortening the Curing Period in Burley Tobacco Stalk Curing)

  • 김상범;백기현;추홍구
    • 한국작물학회지
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    • 제28권2호
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    • pp.252-257
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    • 1983
  • 버어리종 대말림시 백화엽발생을 방지하고 건조기간을 단축하기 위하여 시험을 수행하였던 바, 결과를 요약하면 다음과 같다. 1. 건조실내 온도는 흑색비닐피복구 및 환기창이용구가 관행구보다 $3^{\circ}C$정도 높았으며, 탈수속도는 환기창이용구가 훨씬 빨랐다. 2. 백화엽발생율은 완전대말림구가 높았고, 지면을 30cm 판 처리가 낮았다. 3. 수량감소는 완전대말림구가 컸다. 4. 품질 및 대금은 환기창이용구 및 지면을 30cm판 구가 높았다. 5. 물리성은 줄말림용 차광막처리가 비교적 양호하였다. 6. 백화엽발생을 억제하기 위하여는 첫째, 본포에서 치마름엽과 과숙엽을 방지하고, 둘째, 하위엽은 1-2회 수확한 후 대베기를 실시하며, 셋째, 갈변후에는 건조기간을 단축시키기 위한 온습도관리에 유의해야 할 것으로 생각된다. 7. 버어리종 담배의 물리성을 향상시키면서 건조중 백화의 원인이 되는 산소 및 수분과의 반응을 억제시킬 수 있는 방법에 대하여는 앞으로 더욱 검토가 요구된다.

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In Vivo Measurement of Site-Specific Peritoneal Solute Transport Using a Fiber-Optic-based Fluorescence Photobleaching Technique

  • Lee, Donghee;Kim, Jeong Chul;Shin, Eunkyoung;Ju, Kyung Don;Oh, Kook-Hwan;Kim, Hee Chan;Kang, Eungtaek;Kim, Jung Kyung
    • Journal of the Optical Society of Korea
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    • 제19권3호
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    • pp.228-236
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    • 2015
  • Fluorescence recovery after photobleaching (FRAP) is a well-established method commonly used to measure the diffusion of fluorescent solutes and biomolecules in living cells or tissues. Here a fiber-optic-based FRAP (f-FRAP) system was developed, and validated using macromolecules in water and agarose gels of different concentrations. We applied f-FRAP to measure the site-specific diffusion of fluorescein (NaFluo) in peritoneal membranes (PMs) on the liver, cecum, and kidney of a living rat during peritoneal dialysis. Diffusion of fluorescein in PM varied in a time-dependent manner according to the type of organ ($D_{PM\;on\;Liver}/D_{NaFluo}=0.199{\pm}0.085$, $D_{PM\;on\;Cecum}/D_{NaFluo}=0.292{\pm}0.151$, $D_{PM\;on\;Kidney}/D_{NaFluo}=0.218{\pm}0.110$). The proposed method allows direct quantitative measurement of the three-dimensional diffusion in local PM in vivo, which was previously inaccessible by peritoneal function test methods such as peritoneal equilibration test (PET) and standardized PM assessment (SPA). f-FRAP is promising for local and dynamic assessments of peritoneal pathophysiology and the mass transport properties of PMs, presumed to be affected by variation of tissue structures over different organs and functional changes of the PM with years of peritoneal dialysis.

Probe and Matrix Diffusion of Polystyrene Particle and Labeled Polyallylamine Hydrochlorate

  • Choi, Young-Wook;Sohn, Dae-Won
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.205-205
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    • 2006
  • Adsorption behaviors of positively charged matrix (PAH) onto negatively charged probe (sulfate PS particle) were investigated using DLS (dynamic light scattering) and FPR (fluorescence photobleaching recovery) as view points of matrix and salt concentration. The system experienced sharp decrease of diffusion (flocculation) at dilute condition while the system underwent gradual decrease of diffusion above semi-dilute concentration. With FPR and viscometry experiments, we revealed the probe behaviors in polyelectrolyte solution were strongly affected by the coil overlap concentration (0.5 g/L PAH concentration).

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Structural Stability of High-Temperature State of Bacteriorhodopsin: A Model of Multi-state Membrane Proteins

  • Mitaku, Shigeki;Yokoyama, Yasunori;Sonoyama, Masashi
    • Journal of Photoscience
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    • 제9권2호
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    • pp.118-121
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    • 2002
  • A state of bacteriorhodopsin at high temperature was studied by various spectral measurements. The stability measurements indicated that the onset temperature of the denaturation was 70$^{\circ}C$ in the dark and 60$^{\circ}C$ under illumination. The reactivity of hydroxylamine with the Schiff's base also significantly increased in the temperature range between 60 and 70$^{\circ}C$. A spectral band at about 470 nm appeared in the temperature range higher than 60$^{\circ}C$. The circular dichroism spectra in the visible region started to change from a bilobed exiton type to a positive band at about 60$^{\circ}C$, suggesting that the two-dimensional configuration of bacteriorhodopsin molecules changed from crystalline to amorphous. All the measurements suggested a new state between 60 and 70$^{\circ}C$ in which bacteriorhodopsin is stable only in the dark.

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Photophysical and Photochemical Property of ATX-S10

  • Ito, Toshiaki;Okazaki, Shigetoshi;Kageyama, Kazumi;Hirohata, Toru;Kohno, Eiji;Hirano, Toru
    • Journal of Photoscience
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    • 제9권2호
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    • pp.527-529
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    • 2002
  • Photodynamic therapy (PDT) is a medical treatment using laser and photosensitizing drug taken up to destroy cancer cells. Singlet oxygen ($^1$0$_2$) generation is strongly related to this treatment. We have built a direct detection system monitoring feeble luminescence, in the near IR region, from $^1$0$_2$, We have comparatively studied the photophysical and photochemical properties in solution of a newly developed drug ATX-S10 and Photofrin already investigated clinically. We demonstrdted that ATX-S10 was capable of efficiently yielding $^1$0$_2$, which may lead to highly efficient PDT treatment. Successive laser excitation photobleached ATX -S10 readily in a dose-dependent manner. This result shows that ATX -S10 is useful in setting up suitable medical treatment conditions to minimize side effects.

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세포 및 생체조직에서 확산에 관한 이해 (Understanding Diffusion in Cells and Living Tissues)

  • 김중경
    • 한국가시화정보학회지
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    • 제5권1호
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    • pp.12-15
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    • 2007
  • Macromolecule diffusion in cells and tissues is important for cell signaling, metabolism and locomotion. Biophysical methods, including non-invasive or minimally invasive in-vivo photobleaching techniques and single quantum-dot tracking, have been used to measure the rates of macromolecule diffusion in living cells and tissues, including central nervous system and tumors. Mathematical modeling and statistical analysis of experimental data revealed various modes of diffusion, which are strongly coupled with spatiotemporal changes in nanoscale structures and material properties.