• Title/Summary/Keyword: Activity Determination

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Detection and Determination of Lipase Activity

  • Lee, Seoung-Yong;Rhee, Joon-Shick
    • Journal of Microbiology and Biotechnology
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    • v.4 no.2
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    • pp.85-94
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    • 1994
  • Lipase (triacylglycerol hydrolase, EC 3.1.1.3) is able to catalyze the hydrolysis of ester bonds of triacylglycerols at the interface between aqueous phase and organic phase containing substrate. With the rapid development of lipid biotechnology, lipase-catalyzed hydrolysis of lipids has a great concern from the industrial point of view. Owing to the reversible nature of the lipase, the reactions are also applied for glyceride synthesis, interesterification and resolution of racemic mixtures into optically active alcohols or acids. For all applications of the lipases, a reliable method for the determination of enzyme activity is required. Precise quantitative determination of its activity is essential as the basis of research and development of the bioprocess involving the enzyme. This article reviews the existing literature on the detection and determination of lipase activity from microbial, mammalian and plant sources.

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Practices for Readiness of Future Specialists for Professional Self-Determination in the Information Society

  • Olena Kochubei;Mykola Dubinka;Inna Knysh;Ihor Poliakov;Olga Tsokur;Vasyl Tiahur;Oleksandr Kuchai
    • International Journal of Computer Science & Network Security
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    • v.23 no.12
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    • pp.129-136
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    • 2023
  • Professional self-determination of the individual is a complex and lengthy process of finding and realizing yourself in the profession. The main goal of professional self-determination is clarified. The basic concepts of readiness for professional self-determination of future specialists in the modern information society are revealed. The following approaches to the consideration of the concept of readiness are defined: functional-psychological, personal, activity-based. Based on the components of readiness identified by the researchers, it can be assumed that the structure of professional self-determination of the future specialist contains motivational, cognitive and activity components. Self-determination is defined as a multidimensional process that can be considered from different points of view: as a series of tasks, that society sets for the emerging individual, and which the individual must solve in a certain period. As a process of step-by-step decision-making, with the help of which the individual forms a balance between his desires and inclinations, on the one hand, and the needs of society, on the other; as a process of forming an individual lifestyle, part of which is professional activity. A number of tasks of professional self-determination of a future specialist in the information society are formulated. Diagnostic practices for determining the degree of readiness of future specialists for future professional success are characterized. Practices are developed as a basis for creating an individually oriented correctional and development program to promote the formation of future specialists' focus on future professional success. Their task is to ensure control over the dynamics of this process, assess the effectiveness of this career guidance work. Practices are aimed at identifying the degree of thorough knowledge of the conditions for achieving professional success in the chosen field of activity among future specialists.

Quantitative Comparison of Activity Calculation Methods for the Selection of Most Reliable Radionuclide Inventory Estimation

  • Hwang, Ki-Ha;Lee, Sang-Chul;Lee, Kun-Jai;Jeong, Chan-Woo;Ahn, Sang-Myeon;Kim, Tae-Wook;Kim, Kyoung-Doek;Herr, Y.H.
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.322-327
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    • 2003
  • It is important to know the accurate radionuclide inventory of radioactive waste for the reliable management. However, estimation of radionuclide concentrations in drummed radioactive waste is difficult and unreliable because of difficulties of direct detection, high cost, and radiation exposure of sampling personnel. In order to overcome these difficulties, scaling factors (SFs) have been used to assess the activities of radionuclides that could not be directly analyzed. A radionuclide assay system has been operated at KORI site since 1996 and consolidated scaling factor method has played a dominant role in determination of radionuclides concentrations. However, some problems are still remained such as uncertainty of estimated scaling factor values, inaccuracy of analyzed sample values, and disparity between the actual and ideal correlation pairs and the others. Therefore, it needs to improve the accuracy of scaling factor values. The scope of this paper is focused on the improvement of accuracy and representativeness of calculated scaling factor values based on statistical techniques. For the selection of reliable activity determination method, the accuracy of estimated SF values for each activity determination method is compared. From the comparison of each activity determination methods, it is recommended that SF determination method should be changed from the arithmetic mean to the geometrical mean for more reliable estimation of radionuclide activity. Arithmetic mean method and geometric mean method are compared based on the data set in KORI system.

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Free radical scavenging activity and kinetic behavior of the Galgeuntang water extract

  • Shin, Jeong-Mi;Kim, Young-Ok;Baek, Seung-Hwa
    • Advances in Traditional Medicine
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    • v.8 no.1
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    • pp.32-38
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    • 2008
  • Galgeuntang water extract exhibited a strong free radical scavenging activity and reducing power determination. However, a gradual increase in the free radical scavenging activity and reducing power determination was obtained with increasing concentrations. The highest radical scavenging activity was shown by the water extract from Galgeuntang (116.93 ${\mu}g$/mL) and the water extract from Cinnamonum cassia Presl. (95.01 ${\mu}g$/mL). These results of phenolic and flavonoid contents of the extracts indicated that the strong radical scavenging activity of the Cinnamonum cassia Presl. extract might be in part due to the phenolic compounds. The correlation coefficient between TPC and DPPH ($r^2$ = 0.9312), TFC and DPPH ($r^2$ = 0.9677), showed positive correlation among total phenolic/flavonoid contents and antioxidant activity. These results suggest that Galgeuntang has a potential antioxidant activity.

Development of Radionuclide Inventory Declaration Methods Using Scaling Factors for the Korean NPPs - Scope and Activity Determination Method - (국내 원전 대상의 척도인자를 활용한 핵종재고량 규명 방법의 개발 - 범위 및 방사능 결정 방법-)

  • Hwang, Ki-ha;Lee, Sang-chul;Kang, Sang-hee;Lee, Kun-Jai;Jeong, Chan-woo;Ahn, Sang-myeon;Kim, Tae-wook;Kim, Kyoung-doek;Herr, Young-hoi
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.1
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    • pp.77-85
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    • 2004
  • Regulations and guidelines for radioactive waste disposal require detailed information about the characteristics of radioactive waste drums prior to transport to the disposal sites. However, estimation of radionuclide concentrations in the drummed radioactive waste is difficult and unreliable. In order to overcome this difficulty, scaling factor (SF) method has been used to assess the activities of radionuclides, which could not be directly analyzed. A radioactive waste assay system has been operated at Korean nuclear power plant (KORI site) since 1996 and consolidated SF concept has played a dominant role in the determination of radionuclide concentrations. However, SFs are somewhat dispersive and limited in KORI site. Therefore establishment of the assay system using more improved SFs is planned and progressed. In this paper, the scope of research is briefly introduced. For the selection of more reliable activity determination method, the accuracy of predicted SF values for each activity determination method is compared. From the comparison of each activity determination method, it is recommended that SF determination method should be changed from the arithmetic mean to the geometrical mean for more reliable estimation of radionuclide activity. Arithmetic mean method and geometric mean method are compared based on the data set in KORI system. And, this change of SF determination method will prevent an inordinate over-estimation of radionuclide inventory in radwaste drum.

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Orbit determination for the KOMPSAT-1 Spacecraft during the period of the solar maximum

  • Kim, Hae-Dong;Kim, Eun-Kyou;Choi, Hae-Jin
    • International Journal of Aeronautical and Space Sciences
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    • v.6 no.1
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    • pp.71-76
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    • 2005
  • The KOMPSAT-1 satellite, launched into a circular sun synchronous orbit on Dec. 21, 1999, entered its$6^{th}$year of successful operation this year. The purposes of the mission are to collect earth images (6.6 m resolution), multi-spectral images of the ocean, and to collect information on the particle environment of the low earth orbit. For normal operation, KOMPSAT-1 orbits are determined using GPS navigation solutions. However, at the start of the life of KOMPSAT-1, the 11-year solar activity cycle was at a maximum. Solar flux was maintained at this level until 2002, and thereafter reduced to a moderate level by 2004. Thus, the OD (Orbit Determination) accuracy has varied according to the solar activity. This paper presents the degree to which the OD accuracy could be degraded during a high solar activity period compared with that of a (relatively) low solar activity period. We investigated the effect of the use of solve-for parameters such as a drag coefficient ($C_D$), solar radiation coefficient ($C_R$), and the general accelerations ($G_A$) on OD accuracy with solar activity. For the evaluation of orbit determination accuracy, orbit overlap comparison is used since no independent orbits of comparable accuracy are available for comparison. The effect of the use of a box-wing model instead of a constant cross-sectional area is also investigated.

A Spectrophotometric Assay for Cytochrome P450 Monooxygenase Activity

  • Lee, Sung-Eun;Choi, Won-Sik;Park, Byeoung-Soo;Lee, Byung-Ho
    • Applied Biological Chemistry
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    • v.41 no.4
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    • pp.213-217
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    • 1998
  • An assay for cytochrome P450 monooxygenase activity by determination of the products of organophosphate oxidation via inhibition of acetylcholinesterase was described. Extracts from strains of Oryzaephilus surinamensis selected for resistance to chlorpyrifos-methyl (QVOS 102), fenitrothion (VOS F) and malathion (VOS 3), and a standard susceptible strain VOS 48, were incubated with an organophosphate in the presence of a NADPH-generating system and acetylcholinesterase. The degree of inhibition of the acetylchoinesterase activity was converted to manooxygenase activity using standard curves for the inhibition of acetylcholiesterase by chlorpyrifos-methyl-oxon, fenitrooxon and malaoxan. Activity was detectable in VOS 48 and was present at different increased levels with the different organophosphates in the three resistant strains, suggesting that different forms of P450 might be involved in organophosphate oxidation in these insects. The assays were carried out using crude insect homogenates and much smaller samples of insect material than the standard aldrin to dieldrin assay. It should be possible to use the method for determination of monooxygenase activity in single insert.

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Nephrotoxicity Assessment by Determination of Alanine Aminopeptidase (AAP) and $\beta$-Glucuronidase(GRS) in Rat (랫트뇨중의 Alanine Aminopeptidase와 $\beta$-Glucuronidase 측정에 의한 신장독성 평가에 관하여)

  • Shin Dong-Hwan;Lee Chang Wo
    • Journal of Veterinary Clinics
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    • v.8 no.1
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    • pp.31-45
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    • 1991
  • Present experiment was performed in order to establish the optimal reaction conditions for determination of urinary AAP and GRS activities and to investigate the applicability of urinary AAP and GRS in nephrotoxicity test in rat. The results were as follows ; 1. The optimal pH of phosphate buffer for determination of urinary AAP activity was 7.8. 2. The Michaelis constant of urinary AAP ranged from 0.8 to 1.0mmol/$\ell$ 3. The optimal wave length for determination of urinary GRS activity was 405nm. 4. The optimal pH of acetate buffer for determination of urinary GRS activity was 5.6. 5. The Michaelis constant of urinary GRS ranged from 0.65~0.79mmo1/$\ell$. 6. The AAP activities in gel-filtered samples were significantly higher than those in crude samples. Mean values of AAP activities in gel-filtered samples and crude samples were 29$\pm$20 and 20$\pm$13U/$\ell$, respectively. 7. There was not significant difference between gel-filtered samples and crude samples in urinary GRS activities. Mean values of GRS activities in gel-filtered samples and crude samples were 57$\pm$40 and 56$\pm$39U/$\ell$, respectively. 8. Limits of linearity of urinary AAP and GRS activities were 2.0 and 3.6U/$\ell$, respectively. 9. Within-run imprecisions of the assays, were acceptable, as the coefficients of the AAP activities ranged from 5.5 to 6.3% and those of GRS activities ranged from 1.4 to 6.2%, respectively. 10. Urinary AAP excretion was 675$\pm$227mu/24hrs.kg before administration of potassium dichromate, and increased significantly to 4246$\pm$2567mU/24hrs.kg within 24 hours after administration of potassium dichromate. 11. Urinary GRS excretion did not increase significantly after administration of potassim dichromate. 12. From these findings it is concluded that urinary AAP excretion is early and sensitive Indicator to detect kidney damage in nephrotoxicity experiment.

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NEW DEVELOPMENT OF HYPERGAM AND ITS TEST OF PERFORMANCE FOR γ-RAY SPECTRUM ANALYSIS

  • Park, B.G.;Choi, H.D.;Park, C.S.
    • Nuclear Engineering and Technology
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    • v.44 no.7
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    • pp.781-790
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    • 2012
  • The HyperGam program was developed for the analysis of complex HPGe ${\gamma}$-ray spectra. The previous version of HyperGam was mainly limited to the analysis of ${\gamma}$-ray peaks and the manual logging of the result. In this study, it is specifically developed into a tool for the isotopic analysis of spectra. The newly developed features include nuclide identification and activity determination. An algorithm for nuclide identification was developed to identify the peaks in the spectrum by considering the yield, efficiency, energy and peak area for the ${\gamma}$-ray lines emitted from the radionuclide. The detailed performance of nuclide identification and activity determination was accessed using the IAEA 2002 set of test spectra. By analyzing the test spectra, the numbers of radionuclides identified truly (true hit), falsely (false hit) or missed (misses) were counted and compared with the results from the IAEA 2002 tests. The determined activities of the radionuclides were also compared for four test spectra of several samples. The result of the performance test is promising in comparison with those of the well-known software packages for ${\gamma}$-ray spectrum analysis.