• Title/Summary/Keyword: STABILITY

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The Development of Quality Assurance Program for CyberKnife (사이버나이프의 품질관리 절차서 개발)

  • Jang, Ji-Sun;Kang, Young-Nam;Shin, Dong-Oh;Kim, Moon-Chan;Yoon, Sei-Chul;Choi, Ihl-Bohng;Kim, Mi-Sook;Cho, Chul-Koo;Yoo, Seong-Yul;Kwon, Soo-Il;Lee, Dong-Han
    • Radiation Oncology Journal
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    • v.24 no.3
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    • pp.185-191
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    • 2006
  • [ $\underline{Purpose}$ ]: Standardization quality assurance (QA) program of CyberKnife for suitable circumstances in Korea has not been established. In this research, we investigated the development of QA program for CyberKnife and evaluation of the feasibility under applications. $\underline{Materials\;and\;Methods}$: Considering the feature of constitution for systems and the therapeutic methodology of CyberKnife, the list of quality control (QC) was established and divided dependent on the each period of operations. And then all these developed QC lists were categorized into three groups such as basic QC, delivery specific QC, and patient specific QC based on the each purpose of QA. In order to verify the validity of the established QA program, this QC lists was applied to two CyberKnife centers. The acceptable tolerance was based on the undertaking inspection list from the CyberKnife manufacturer and the QC results during last three years of two CyberKnife centers in Korea. The acquired measurement results were evaluated for the analysis of the current QA status and the verification of the propriety for the developed QA program. $\underline{Results}$: The current QA status of two CyberKnife centers was evaluated from the accuracy of all measurements in relation with application of the established QA program. Each measurement result was verified having a good agreement within the acceptable tolerance limit of the developed QA program. $\underline{Conclusion}$: It is considered that the developed QA program in this research could be established the standardization of QC methods for CyberKnife and confirmed the accuracy and stability for the image-guided stereotactic radiotherapy.

Characteristics of alkaline and acid phosphatase in Spirometra erinacei (만손열두조충(Spirometra erinacei)에서 알칼리성과 산성 인산효소의 특성)

  • 곽기훈;김창환
    • Parasites, Hosts and Diseases
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    • v.34 no.1
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    • pp.69-78
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    • 1996
  • This study was done to investigate the enzyme-histochemical localization and characteristics of alkaline and acid phosphatase related with metabolism in sparganum and adult of Spirometrn erinacei. By the enzyme-histochemical assay, the alkaline and acid phosphatases were localized in the tegument and subtegumental musculature of sparganum and adult, but not in the parenchyma. The activities of alkaline phosphatase were stronger in the tegument than in the subtegumental musculature, and activities of acid phosphatase were stronger in the tegument of adults than those of sparganum. The 2 isozymes of alkaline and acid phosphatases were separated from s-sparganum (from snake) and r-sparganum (from experimentaly infected rats) respectively but 4 isozymes of Alp and 3 isoxymes of Acp were separated from adult worms by electrophoresis. In isogyme Alp, the 661)a was the common isozyme, but 130 kDa isozyme of Acp was the common isozyme in spargana and adult worms. By isoelectrofocusing, 4 isozymes (PI 7.9, 7.7, 6.5 and 6.3) and 2 isozymes (PI 7.9 and 7.7) of alkaline phosphatase were separated from adults and spargana respectively. In the stability against heat, activity of alkaline phosphatase was denatured perfectly after heating at 90℃ for 40 seconds. The optimum pH and temperature for activity of alkaline phosphatase were about pH 10 and 50℃, respectively. The maximum activity (unit) of alkaline phosphatase was 22.0 in s- sparganum,25.0 in r-sparganum and 215.0 in adult worms, so that the maximum activity was revealed higher in adults than spargana. As the result from above, we observed that alkaline and acid phosphatases were functioned mainly in the tegument and subtegumental musculature , and the isoxymes of phosphatase were activated differently according to habitat of the parasites. The spargana and adult worms carry out the pafasitism by adapting thenlselves to parasitic circumstance loth these emxymes.

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Localization and characteristics of lactate and palate dehydrogenase in the sparganum and adult worm of Spirometra erinacei (만손열두조충에서 젖산탈수소효소와 말산탈수소효소의 분포와 특징)

  • Gwak, Gi-Hun;Jeon, Eun-U;Kim, Chang-Hwan
    • Parasites, Hosts and Diseases
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    • v.34 no.1
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    • pp.59-68
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    • 1996
  • This study investigated the enzyme histochemical localization and characteristics of lactate (LDH) and malate dehydrogenase (MDH) related with the oxidation-reduction metabolism in the sparganum and adult of 5. erinacei. By enzyme histochemical assay, activity of LDH was strong in the tegument and subtegumental muscle layers of the adult and sparganum. Activity of MDH was strong in the tegument of the sparganum and subtegumental muscle layers of the adult. However it was weak in the tegument of the adult. By electrophoresis, 45 kDa band was major and common in LDH of adults and spargana. The 150 kDa molecule was the major and common band in MDH of adults and r -spargana (from experimentally infected rats) . By isoelectrofocusing, isoelectric points (Pl) or 4 MDH isogyme from adult worm were 6.0.6.5, 6.7 and 7.1, respectively. Pl 6.0 was the major band. The active range of pH for MDH was about pH 6-8 and the optimum pH was pH 7 The effective temperature on the MDH was about $30^{\circ}C$$50^{\circ}C$ and the optimum temperature was about 40℃ in spargana md adult worm. In the stability against heat, when MDH was heated at 85℃ for 10 seconds, the activity was denatured perfectly. Maximum activity or MDH was 19.4 unit in the s-sparganum (from snakes), 24.5 unit in the r-sparganum (from rats) and 108.0 unit in the adult worm. The maximum activity was higher in adults than in spargana. The present result showed us that the nutrients absorbed through the tegument were transferred into inner tissues and were utilized as the source of metabolism. According to the habitat of the parasite, the isozymes of LDH and MDH are activated differently, and by this different activation the sparganum and adult can adapt themselves to parasitic circumstances.

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The Effect of Paprika (Capsicum annuum L.) on Inhibition of Lipid Oxidation in Cooked-Ground Pork during Storage (파프리카 첨가가 분쇄조리돈육 저장 중 지방산화억제에 미치는 영향)

  • Park, Jae-Hee;Kim, Chang-Soon;Kim, Hyuk-Il
    • Korean journal of food and cookery science
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    • v.23 no.5
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    • pp.626-634
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    • 2007
  • This study investigated the effects of 3% ground fresh paprika (FP) and 5% freeze-dried paprika powder (FDP) on lipid oxidation inhibition and warmed-over flavor (WOF) development in cooked ground pork (CGP; meat:fat = 70:30), using two packaging methods (atmosphere packaging and vacuum packaging) during 8 days at $4^{\circ}C$ and 4 months at $-26^{\circ}C$. In the CGP containing FP with atmosphere packaging, at both $4^{\circ}C\;and\;-26^{\circ}C$, peroxide formation increased sharply, and was similar to that of the CGP without paprika. Peroxide formation, in both the CGP without paprika and with FP and packaged with vacuum packaging, repectively, was much lower than that found with atmosphere packaging. Vacuum packaging was superior to atmosphere packaging for lipid oxidation inhibition. In the CGP containing FP with vacuum packaging and stored at $-26^{\circ}C$, peroxide formation almost didn't occur, which was similar to the CGP containing FDP. The peroxide value and thiobarbituric acid (TBA) value did not increase in the CGP containing FDP over the storage periods ($4^{\circ}C\;and\;-26^{\circ}C$) for both the atmosphere and vacuum packaging. Therefore, FDP was the most effective for lipid oxidation inhibition during refrigerated storage, regardless of the packaging method. Both FP and FDP with vacuum packaging during frozen storage showed similar antioxidant activities. The development of WOF in the CGP containing FDP with vacuum packaging was delayed until 7 days at $4^{\circ}C$ and 3 months at $-26^{\circ}C$, respectively. WOF was highly correlated with TBA value in the CGP stored at $-26^{\circ}C$ with vacuum packaging (r = 0.88, p<0.05). The oxidative stability of the lipid in the CGP containing FDP with vacuum packaging was excellent.

Motion Analysis of Light Buoys Combined with 7 Nautical Mile Self-Contained Lantern (7마일 등명기를 결합한 경량화 등부표의 운동 해석)

  • Son, Bo-Hun;Ko, Seok-Won;Yang, Jae-Hyoung;Jeong, Se-Min
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.5
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    • pp.628-636
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    • 2018
  • Because large buoys are mainly made of steel, they are heavy and vulnerable to corrosion by sea water. This makes buoy installation and maintenance difficult. Moreover, vessel collision accidents with buoys and damage to vessels due to the material of buoys (e.g., steel) are reported every year. Recently, light buoys adopting eco-friendly and lightweight materials have come into the spotlight in order to solve the previously-mentioned problems. In Korea, a new lightweight buoy with a 7-Nautical Mile lantern adopting expanded polypropylene (EPP) and aluminum to create a buoyant body and tower structure, respectively, was developed in 2017. When these light buoys are operated in the ocean, the visibility and angle of light from the lantern installed on the light buoys changes, which may cause them to function improperly. Therefore, research on the performance of light buoys is needed since the weight distribution and motion characteristics of these new buoys differ from conventional models. In this study, stability estimation and motion analyses for newly-developed buoys under various environmental conditions considering a mooring line were carried out using ANSYS AQWA. Numerical simulations for the estimation of wind and current loads were performed using commercial CFD software, Siemens STAR-CCM+, to increase the accuracy of motion analysis. By comparing the estimated maximum significant motions of the light buoys, it was found that waves and currents were more influential in the motion of the buoys. And, the estimated motions of the buoys became larger as the sea state became worser, which might be the reason that the peak frequencies of the wave spectra got closer to those of the buoys.

Quality Characteristics of the Flesh and Juice for Different Varieties of Sweet Pumpkins (단호박의 품종에 따른 과육 및 착즙액의 품질 특성)

  • Kim, Mi-Hyang;Lee, Woo-Moon;Lee, Hee-Ju;Park, Dong-Kum;Lee, Myung-Hee;Youn, Sun-Joo
    • Food Science and Preservation
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    • v.19 no.5
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    • pp.672-680
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    • 2012
  • To determine the characteristics of four different sweet pumpkins (Minimam, Bojjang, Ajikuroi and Kurijiman), juices were made from these varieties. The carotenoids in the flesh were 1.5~2 times higher than those in the skin and were highest in the flesh of the Minimam pumpkin among all the pumpkin varieties studied. The vitamin A contents were higher in the skin than in the flesh, and Minimam had the highest vitamin A content (2,016.57 IU/100 g) while Kurijiman had the lowest (998.83 IU/100 g). The vitamin C contents varied from 43.21 to 82.35 mg%, but there were no significant differences between the flesh and the skin. That of Kurijiman was the highest among the varieties studied. The major mineral of these varieties was potassium, which was highest in the flesh of Ajikuroi, followed by phosphorus. The antioxidant activities of the sweet pumpkin water extracts were higher in the skin than in the flesh. The $EC_{50}$ of the Minimam skin was the highest (4.01 mg/mL), and that of the Ajikuroi flesh was the lowest. The sweet pumpkin juice yields were 69.5~89.4%, with significant differences shown according to the variety. That of the peeled Ajikuroi's flesh was the highest. The pH was 7.17~7.83, and the unpeeled sweet pumpkin's pH was higher than that of the peeled sweet pumpkin. The Brix degree was $12.5{\sim}16.6^{\circ}Brix$, with that of the unpeeled Bojjang being the highest($16.1^{\circ}Brix$) and that of the unpeeled Ajikuroi the lowest ($12.7^{\circ}Brix$). The sweet pumpkin beverage made with pressed juice was adjusted by pH 3.5 with citric acid, and the Brix degree was maintained at the $12^{\circ}Brix$ with sugar. The adjusted beverage, which was the peeled pumpkin flesh juice, had suspension stability for a short time. The sweet pumpkin beverage had a certain flovor and a slimy mouthfeel. Bojjang and Kurijiman were evaluated as the best in the terms of taste and color, but the peeled Minimam and Bojjang showed the best results overall.

Effect of supercooling on the storage stability of rapidly frozen-thawed pork loins (과냉각 온도가 급속냉동-해동 처리된 돈육 등심의 저장성에 미치는 영향)

  • Choi, Eun Ji;Park, Hae Woong;Chung, Young Bae;Kim, Jin Se;Park, Seok Ho;Chun, Ho Hyun
    • Food Science and Preservation
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    • v.24 no.2
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    • pp.168-180
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    • 2017
  • This study was performed to determine the rapid thawing method for reducing the thawing time of frozen pork loins and to examine the effects of supercooling on the microbiological, physicochemical, and sensory qualities of fresh and frozen-thawed pork during storage at -1.5, 4, and $15^{\circ}C$. Forced-air thawing at $4^{\circ}C$ was the most time-consuming process, whereas radio frequency thawing time was the shortest by dielectric heating. The supercooling storage temperature was chosen to be $-1.5^{\circ}C$ because microstructural damages were not observed in the pork sample after cooling at $-1.5^{\circ}C$ for 24 h. Fresh or frozen-thawed pork loins stored at $-1.5^{\circ}C$ had lower drip loss and total volatile base nitrogen, thiobarbituric acid-reactive substance, and Hunter b* levels than loins stored at 4 and $15^{\circ}C$. In addition, the least degree of increase in preexisting microorganisms counts of the fresh or frozen-thawed pork loin samples was obtained during supercooled storage at $-1.5^{\circ}C$. Sensory quality results of fresh and frozen-thawed pork loin samples stored at $-1.5^{\circ}C$ showed higher scores than the samples stored at 4 and $15^{\circ}C$. These data indicate that supercooling at $-1.5^{\circ}C$ in the meat processing industry would be effective for maintaining the quality of pork meats without ice crystal nucleation and formation.

Formation and Dissociation Kinetics of Zinc(II) Complexes of Tetraaza-Crown-Alkanoic Acids (Zinc(Ⅱ) Tetraaza-Crown-Allkanoic Acids 착물의 형성 및 해리 반응속도론)

  • Choi, Ki Young;Kim, Dong Won;Kim, Chang Suk;Park, Byung Bin;Choi, Suk Nam;Hong, Choon Pyo;Ryu, Hae Il
    • Journal of the Korean Chemical Society
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    • v.44 no.5
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    • pp.403-409
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    • 2000
  • The formation and dissociation rates of $Zn^{2+}$ Complexes with l,4,7,10-tetraaza-13,16-diox-acyclooctadecane-N,N',N",N'"-tetraacetic acid (1), 1,4,7,10-tetraaza-13,16- dioxacyclooctadecane-N,N',N",N'"-tetramethylacetic acid (2), and 1,4,7,10-tetraaza-13,16- dioxacyclooctadecane-N,N',N",N'"-tetrapropionic acid(3) have been measured by stopped-flow and conventional spectrophotometry. Observations were made at 25.0$\pm$0.1 $^{\circ}C$ and at an ionic strength of 0.10 M NaClO$_4$. The formation reactions of $Zn^{2+}$ ion with 1 and 2 took place by the rapid formation of an intermediate complex (ZnH$_3L^+$) in which the $Zn^{2+}$ ion is incompletely coor-dinated. This might then lead to be a final product in the rate-determining step.ln the pH range 4.76-5.76, the diprotonated (H2L2-) form is the kinetically active species despite of its low concentration. The stability con-stants (log$K_{(ZnH$_3$3$L^+$)}$) and specific water-assisted rate constants (koH) of intermediate complexes have been deter-mined from the kinetic data. The dissociation reactions of $Zn^{2+}$ complexes of 1,2, and 3 were investigated with $Cu^{2+}$ ions as a scavenger in acetate buffer. All complexes exhibit acid-independent and acid-catalyzed con-tributions. The effect of buffer and $Cu^{2+}$ concentration on the dissociation rate has also been investigated. The ligand effect on t dissociation rate of $Zn^{2+}$ complexes is discussed in terms of the side-pendant armsand the chelate ring sizes of the ligands.

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Morphological, Physiological andd Biochemical Characteristics of Early Senescence Mutant in Rice (Oryza sativa L) (벼의 조기노화 변이체의 형태, 생리 및 생화학적 특성)

  • 이숙영
    • Korean Journal of Plant Resources
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    • v.8 no.3
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    • pp.325-334
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    • 1995
  • The early senescence mutant induced from Gihobyeo by $\gamma-ray$ irradiation was determined. The mutated gene expression was identified with comparing the characteristic of original cultivar. The mutant had so similar the morphological characteristics to original cultivar that it couldn't be distinguished until senescence occurred at about 20 days after heading. Suddenly yellow leaves were observed within a few days due to great decreases in total chlorophyll and various carotenoid contents. Transmission electron microscopy showed the formation of starch granules, distortion of fine structure of leaf cell organelles, especially grana structures, and the decrease in grain filled after senescence occurred. But banding patterns of total proteins and isozymes have not show any differences, The early senescence mutant will be very useful for study material not only on physiological and biochemical properties of plant senescence but also on gene expression regulating senescence which gives great influence on yield potential and its stability.

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Studies on the Nutri-Culture of Major Wild Vegetable Ligularia fischeri Turcz I. Growth and Yield of Ligularia fischeri Turcz. by Media, Amount of Media and Planting Density in Nutri-Culture (곰취의 양액재배 기술 개발 I. 배지종류 , 배지량 , 재식밀도에 따른 곰취의 생육 및 수량)

  • 홍정기
    • Korean Journal of Plant Resources
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    • v.10 no.4
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    • pp.401-410
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    • 1997
  • This experiment was conducted to investigate the opimum media, media amount and planting density of nutri-culture for the high quality and yield of wild vegetable, Liguliaria fischeri Turez. The fried rice hull was recognized best media among perlite, sand and fried rice hull for nutri-culture of Ligularia fischeri Turcz. The yield on fried rice hull media at early growing stage was lower, but higher than in other media at late growing stage. Therefore, total yield in fried rice hull media was 15-29% higher than that of the existing perlite media. Growth and yield of Ligularia fischeri Turcz. were not significantly different between medium amounts, therefore considering economical efficiency and stability, the optimum medium amount was 105 $\iota/m^3$, Yield by planting density increased in the high density and 50 plants/$m^2$ was considered as proper planting density in nutri-culture of Liguliaria fishcheri Turcz.

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