• 제목/요약/키워드: fluorescence life time

검색결과 67건 처리시간 0.028초

가속열화 된 CSPE 상태감시법 유효성 평가 (A Study on Practicality of Condition Monitoring Method of Accelerated Thermal Aging CSPE)

  • 이정훈;구철수;김인용;신용덕
    • 전기학회논문지
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    • 제60권11호
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    • pp.2088-2092
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    • 2011
  • The accelerated thermal aging of CSPE(chloro sulfonate polyethylene) of test cables were carried out for the period equal to 10, 20 and 30 years in air at $100^{\circ}C$, respectively. The CSPE cables(TAIHAN electric wire Co. Ltd) which installed in nuclear power plant for three years were used as starting materials. Condition monitering methods of the accelerated thermal aging of CSPE cables were estimated through indenter modulus and OIT(oxidation induction time) of IEC 62582, and those were newly estimated through volume electrical resistivity, ultrasound reflection time, density, FE-SEM(field emission scanning electron microscopy), XPS(x-ray photoelectron spectroscopy), EDS(energy dispersive spectroscopy), and WD-XRF(wavelength dispersive x-ray fluorescence). A new condition monitoring methods of the accelerated thermal aging of CSPE cables were generally coincident with trend of indenter modulus expect EDS, XPS and XRF. A volume electrical resistivity among new condition monitoring methods of the accelerated thermal aging of CSPE cables is excellent. It is considered that life-time of CSPE cable can be predicted through volume electrical resistivity, if CSPE jacket was aged for period such as more than 20 years.

Influence of Pulsed Electric Field on Accumulation of Calcium in Lactobacillus rhamnosus B 442

  • Goral, Malgorzata;Pankiewicz, Urszula;Sujka, Monika;Kowalski, Radoslaw;Giral, Dariusz;Kozlowicz, Katarzyna
    • Journal of Microbiology and Biotechnology
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    • 제30권1호
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    • pp.44-53
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    • 2020
  • Calcium is an element that performs many important functions in the human body. A study was conducted on the use of a pulsed electric field (PEF) to enrich cells of Lactobacillus rhamnosus B 442 in calcium ions. The highest concentration of calcium ions in bacterial cells (7.30 mg/g d.m.) was obtained at ion concentration of 200 ㎍/ml of medium and with the use of the following PEF parameters: field strength 3.0 kV/cm, exposure time 10 min, pulse width 75 ms and 20 h of culturing after which bacteria were treated with the field. Cell biomass varied in the range from 0.09 g/g d.m. to 0.252 g/g d.m., and the total number of bacteria ranged from 1010 CFU/ml to 1012 CFU/ml. Microscope photographs prove that calcium ions were situated within the cells of the bacteria, and electroporation contributed to an increase in the effectiveness of the ion bioaccumulation process. Samples containing calcium and subjected to electroporation displayed intensive fluorescence. The significance of this research was the possibility of using probiotic bacteria enriched with calcium ions for the production of functional food in subsequent studies.

분변내 성호르몬의 분석을 통한 멸종위기 사육 오랑우탄에서의 번식형태 (The Reproductive Patterns of Endangered Captive Orangutans by Analysing the Sex Hormones in Feces)

  • 정소영;김보숙;윤용달
    • 한국임상수의학회지
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    • 제30권1호
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    • pp.22-26
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    • 2013
  • To monitor the reproductive patterns of endangered orangutan, Time-resolved fluorescence immuno assay (TR-FIA) were used to analyze metabolites of sex hormones in feces. Orangutan had long-term interbirth intervals (amenorrhea) during lactation period in which the secretion of sex hormones was repressed. The concentration of progesterone in the serum of pregnant orangutan was 30fold higher than that in non-pregnant orangutan. However, the concentration of hCG during pregnant period was different from the result of other primates. The present study suggested that age is not the important factor in determining the reproduction capability, because it is rather greatly influenced by the combination of various factors. Tracing metabolites of sex hormones in orangutan feces seems to be provide the effective solution for the infertility in orangutan. This study result shows the basic data in operating conservation project for endangered orangutan.

Synergistic extraction of lanthanoids(III) with thenoyltrifluoroacetone and aromatic carboxylic acids and the hydration of the extracted species

  • Ishiwata, E.;Kimura, T.;Kato, Y.;Hasegawa, Y.
    • 분석과학
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    • 제8권4호
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    • pp.499-503
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    • 1995
  • In order to study how and why the stabilities of lanthanoid(III) complexes in solutions vary across the series, the formation constants of the adducts of tris(2-thenoyltrifluoroacetonato)lanthanoids(III) with seven carboxylic acids in chloroform have been determined by solvent extraction technique at 298K. The formation constants with carboxylic acids generally decrease with increasing the atomic number, but in the middle of the series, they change only slightly. Such trends have been interpreted as related to a change of the coordination number in the middle of the series. It has been attempted to determine the number of water molecules coordinated to the adducts as well as $Eu(TTA)_3$ in chloroform by measuring the fluorescence life time of europium(III), to ensure the assignment of the coordination number.

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핵 염색을 이용한 세포사멸 유도물질 스크리닝의 조건 비교 (Comparison of Conditions for Cell Death-Inducing Agents Using a High Throughput-Compatible Nuclear Staining Assay)

  • 이상한
    • 생명과학회지
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    • 제18권9호
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    • pp.1312-1315
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    • 2008
  • DAPI 염색을 이용하여 세포사멸 유도물질의 초고속스크리닝에 적합한 protocol을 제작하였다. Liquid handler에서 dispensing과 multilabel counter에서의 상대적인 fluorescent intensity를 측정하는 과정을 자동화한 protocol을 제작하였고, 이의 과정은 매우 효율적으로 가동되었음을 확인하였다. DAPI에 binding된 DNA의 intensity를 측정하는 조건검토에서 가장자리의 36개를 reading하지 않는 것이 edge effect를 줄일수 있는 것을 확인하였고, 0.1 sec reading으로 시간을 절약할 수 있었다. 이의 결과를 효과적으로 이용할 경우, 세포사멸 유도물질의 초고속스크리닝 또는 이에 적합한 스크리닝이 가능함을 확인하였다.

사람 혈장 중 부메타니드의 HPLC 분석법 검증 및 단일 용량 투여에 의한 약물동태 연구 (Determination of Bumetanide in Human Plasma by a Validated HPLC Method and Its Application to Single-dose Pharmacokinetics)

  • 박혜영;곽혜선;전인구
    • Journal of Pharmaceutical Investigation
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    • 제35권1호
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    • pp.51-55
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    • 2005
  • A high-performance liquid chromatographic method was employed for the determination of bumetanide in human plasma. After addition of internal standard (IS, naproxen) and acidification of the plasma with 1 M hydrochloric acid, the drug and IS were extracted into dichloromethane. The organic phase was back-extracted into 1 M sodium bicarbonate solution and 50 ${\mu}l$ of the aqueous phase was injected onto a reversed-phase C18 column with a mobile phase consisting of methanol: water: glacial acetic acid = 65 : 35 : 1. The samples were detected utilizing a fluorescence detector (excitation wavelength 235 nm, emission wavelength 405 nm). The method was specific and validated with a lower limit of 5 ng/mL. Intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification. The applicability of the method was demonstrated by analysis of plasma after oral administration of a single 2 mg dose to 24 healthy subjects. From the plasma bumetanide concentration vs. time curves, the mean AUC was $246.5{\pm}73.8\;ng{\cdot}hr/mL$ and $C_{max}$ of $132.1{\pm}40.9$ ng/mL reached 1.2 hr after administration. The mean biological half-life of burnet ani de was $1.1{\pm}0.2$hr. Based on the results, this simple and validated assay method could readily be used in any pharmacokinetic or bioequivalence studies using humans.

Novel Effects of Polyelectrolytes on Fluorescence Quenching of Tris(2,2$^\prime$-bipyridine)ruthenium(Ⅱ) by Methyl Viologen and Cu$^{2+}$

  • Park, Joon-Woo;Paik, Young-Hee
    • Bulletin of the Korean Chemical Society
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    • 제6권5호
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    • pp.287-291
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    • 1985
  • The addition of poly(styrenesulfonate) (PSS) to $Ru(bpy)_3^{2+}$ solutions shifted the emission peak by 3 nm to red, and increased emission intensity by 1.8 times. By contrast, poly(vinylsulfonate) (PVS) had little effect on the fluorescence spectrum. The effects of PSS on the spectral properties of $Ru(bpy)_3^{2+}$, were attributed to the presence of a hydrophobic phenyl group in PSS, which interact with $Ru(bpy)_3^{2+}$ by, at least in part, hydrophobic effect. The binding constant of $Ru(bpy)_3^{2+}$ to PSS in 0.1 M NaCl was $6{\times}10^4\;M^{-1}$, and this value was about $10^3$ times higher than those of methyl viologen ($MV^{2+}$) and $Cu^{2+}$. The Stern-Volmer constants of emission quenching of $Ru(bpy)_3^{2+}$ by $MV^{2+}$ and $Cu^{2+}$ in 0.1 M NaCl solutions were 426 and 40 $M^{-1}$, which correspond to second order rate constants($k_q$) of $1.1{\times}10^9\;and\; 1.0{\times}10^8\;M^{-1}s^{-1}$, respectively. The presence of PSS enhanced $K_{SV's}\;by\;{\sim}50$ times, whereas PVS increased the values only 1-4 times. The large enhancing effect of PSS, despite of lower charge density than PVS, was explained in terms of longer life-time of photoexcited $Ru(bpy)_3^{2+}$ bound to PSS and strong association of $Ru(bpy)_3^{2+}$ to PSS due to a specific interaction involving hydrophobic effect. The variation of $K_{SV's}$ on the concentrations of PVS and PSS were also investigated for $Ru(bpy)_3^{2+}-MV^{2+}\;and \;Ru(bpy)_3^{2+}-Cu^{2+}$ photoredox systems.

Numerical Model for Cerebrovascular Hemodynamics with Indocyanine Green Fluorescence Videoangiography

  • Hwayeong Cheon;Young-Je Son;Sung Bae Park;Pyoung-Seop Shim;Joo-Hiuk Son;Hee-Jin Yang
    • Journal of Korean Neurosurgical Society
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    • 제66권4호
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    • pp.382-392
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    • 2023
  • Objective : The use of indocyanine green videoangiography (ICG-VA) to assess blood flow in the brain during cerebrovascular surgery has been increasing. Clinical studies on ICG-VA have predominantly focused on qualitative analysis. However, quantitative analysis numerical modelling for time profiling enables a more accurate evaluation of blood flow kinetics. In this study, we established a multiple exponential modified Gaussian (multi-EMG) model for quantitative ICG-VA to understand accurately the status of cerebral hemodynamics. Methods : We obtained clinical data of cerebral blood flow acquired the quantitative analysis ICG-VA during cerebrovascular surgery. Varied asymmetric peak functions were compared to find the most matching function form with clinical data by using a nonlinear regression algorithm. To verify the result of the nonlinear regression, the mode function was applied to various types of data. Results : The proposed multi-EMG model is well fitted to the clinical data. Because the primary parameters-growth and decay rates, and peak center and heights-of the model are characteristics of model function, they provide accurate reference values for assessing cerebral hemodynamics in various conditions. In addition, the primary parameters can be estimated on the curves with partially missed data. The accuracy of the model estimation was verified by a repeated curve fitting method using manipulation of missing data. Conclusion : The multi-EMG model can possibly serve as a universal model for cerebral hemodynamics in a comparison with other asymmetric peak functions. According to the results, the model can be helpful for clinical research assessment of cerebrovascular hemodynamics in a clinical setting.

Detection of transgene in early developmental stage by GFP monitoring enhances the efficiency of genetic transformation of pepper

  • Jung, Min;Shin, Sun-Hee;Park, Jeong-Mi;Lee, Sung-Nam;Lee, Mi-Yeon;Ryu, Ki-Hyun;Paek, Kee-Yoeup;Harn, Chee-Hark
    • Plant Biotechnology Reports
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    • 제5권2호
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    • pp.157-167
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    • 2011
  • In order to establish a reliable and highly efficient method for genetic transformation of pepper, a monitoring system featuring GFP (green fluorescent protein) as a report marker was applied to Agrobacteriummediated transformation. A callus-induced transformation (CIT) system was used to transform the GFP gene. GFP expression was observed in all tissues of $T_0$, $T_1$ and $T_2$ peppers, constituting the first instance in which the whole pepper plant has exhibited GFP fluorescence. A total of 38 T0 peppers were obtained from 4,200 explants. The transformation rate ranged from 0.47 to 1.83% depending on the genotype, which was higher than that obtained by CIT without the GFP monitoring system. This technique could enhance selection power by monitoring GFP expression at the early stage of callus in vitro. The detection of GFP expression in the callus led to successful identification of the shoot that contained the transgene. Thus, this technique saved lots of time and money for conducting the genetic transformation process of pepper. In addition, a co-transformation technique was applied to the target transgene, CaCS (encoding capsaicinoid synthetase of Capsicum) along with GFP. Paprika varieties were transformed by the CaCS::GFP construct, and GFP expression in callus tissues of paprika was monitored to select the right transformant.

Sex Ratio Determination by Quantitative Real Time PCR using Amelogenin Gene in Porcine Sperm

  • Hwang, You-Jin;Bae, Mun-Sook;Yang, Jae-Hun;Kim, Bo-Kyoung;Kim, Sang-Ok;Lee, Eun-Soo;Choi, Sun-Gyu;Kwon, Ye-Ri;Seo, Min-Hae;Park, Choon-Keun;Kim, Dae-Young
    • 한국수정란이식학회지
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    • 제24권3호
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    • pp.225-230
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    • 2009
  • Sex-sorting of sperm is an assisted reproductive technology (ART) used by the livestock industry for the mass production of animals of a desired sex. The standard method for sorting sperm is the detection of DNA content differences between X and Y chromosome-bearing sperm by flow cytometry. However, this method has variable efficiency and therefore requires verification by a second method. We have developed a sex determination method based on quantitative real-time polymerase chain reaction (qPCR) of the porcine amelogenin (AMEL) gene. The AMEL gene is present on both the X and the Y chromosome, but the length and sequence of its noncoding regions differ between the X and Y chromosomes. By measuring the threshold cycle (Ct) of qPCR, we were able to calculate the relative frequency of X chromosome. Two sets of AMEL primers were used in these studies. One set (AME) targeted AMEL gene sequences present in both X and Y chromosome, but produced PCR products of different lengths for each chromosome. The other set (AXR) bound to AMEL gene sequences present on the X chromosome but absent esholthe Y-chromosome. Relative product levels were calculated by normalizing the AXR fluorescence to the AME fluorescence. The AMEL method accurately predicted the sex ratios of boar sperm, demonstrating that it has potential value as a sex determination method.