• Title/Summary/Keyword: 변색

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CHEMICAL DEGRADATION OF VARIOUS COMPOMERS IN NaOH (콤포머의 NaOH 용액 내에서의 화학적 분해)

  • Park, Mi-Ran;Choi, Nam-Ki;Lee, Young-Jun;Kim, Seon-Mi;Yang, Kyu-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.2
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    • pp.144-152
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    • 2004
  • The aim of this study was to evaluate the resistance to degradation of three commercial compomers in an alkaline solution. Dyract(Dentsply), Elan(Kerr) and F-2000(3M) polyacid modified resin composites(compomers) were used in this study. The resistance to degradation was evaluated on the basis of mass loss(%), degradation $depth({\mu}m)$ and Si, Al, Ba loss(ppm). The results were as follows : 1. The mass loss of each brand was $1.42%{\sim}2.14%$ and there was no statistically significant difference of mass loss among Dyract, F2000 and Elan. 2. The degradation layer depth of each brand was $182.92{\sim}227.7{\mu}m$ and there was no statistically significant difference of degradation layer depth among Dyract, F2000 and Elan. 3. There was statistically significant differences in Si-loss and Al-loss among three compomers (p<0.05). Si loss was the highest value in Dyract and Al loss was the highest value in F2000. 4. There was statistically significant correlation between mass loss and degradation layer depth (r=0.60, p<0.05). 5. In SEM finding, there was some destruction of compomer matrix-filler interface in post-exposure specimen to NaOH solution. As the matrix decreased, the filler particles distinguished and the periphery of the filler particles appeared whitish color due to degradation.

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Reevaluation of Clinical Efficacy of Peripheral Vasodilator: Ethaverine HCl (말초혈관(襪梢血管) 확장제(擴張劑) Ethaverine HCl의 임상효과(臨床效果)의 재평가(再評價))

  • Kim, Yoon-Young;Cho, Young-W.
    • The Korean Journal of Pharmacology
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    • v.11 no.1 s.17
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    • pp.33-38
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    • 1975
  • The clinical efficacy of Ethaverine, a peripheral vasodilator, was studied according to a double-blind, non-cross over method in 29 diabetic patients with peripheral arterial diseases. The clinical improvement was assessed from the history of patients including the incidence and frequency of intermitten claudication. Ethaverine, after 4 weeks of therapy, was not effective in improving clinical symptoms compared to placebo. Ethaverine, however, was an efective vasodilator than placebo. The quality of vasodilation induced by Ethaverine, was similar to that of alcohol. A new clinical method of studying peripheral vasodilator was presented. The clinical symptoms of peripheral vascular arterial disease in the lower extrimities include reduced intensity of palpable pulses, coldness, and discoloration of the skin. Intermittent claudication may be present. Pathologic changes in vessel architecture precede the symptoms, and recognition of impending vascular insufficiency is a determining factor in selecting vasodilating therapy or surgical management. Also, post-operative patients who have chronic peripheral vascular arterial disease may be candidates for subsequent vasodilating therapy. Peripheral vasodilators, according to the series of reports, may be indicated in vasospastic peripheral vascular condition rather than an occlusive vascular disease and the vessel responds best when a relatively large vascular beds are involved rather than a small, capillary beds. Recently, the clinical efficacy of peripheral vasodilators have been challanged by many clinical investigators and clinicians. In this study, we have re-evaluated the efficacy of Ethaverine HCl as peripheral vasodilator in patients with vasospastic peripheral arterial disease. Ethaverine is claimed to be two to four times as potent a spasmolytic agent as papaverine in a variety of laboratory and clinical work.

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BOND STRENGTH AND MICROLEAKAGE IN RESIN BONDING TO TOOTH STRUCTURE (치질접착에서 접착강도와 변연누출)

  • Kim, Jin-Hee;Park, Jeong-Won;Park, Jin-Hoon;Kim, Sung-Kyo
    • Restorative Dentistry and Endodontics
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    • v.24 no.4
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    • pp.570-577
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    • 1999
  • Intuitively, higher bond strengths should result in less leakage. However, the relationship between bond strengths and microleakage value is complex and not clearly understood. The purpose of this study was to evaluate the relationship between tensile bond strengths and microleakage values in the same restorations to understand the behavior of resin bonding to tooth structure. One-hundred and twenty enamel or dentin specimens from freshly extracted bovine mandibular incisors were used. The specimen was treated with 32% phosphoric acid for 15 seconds and rinsed for 20 seconds. the teeth were divided into four groups by means of wet bonding technique or dry bonding. One-Step$^{TM}$ adhesive were applied to the specimen. The specimens were immersed in 2% methylene blue solution for 7 days, and tensile bond strength and microleakage were measured. The results were as follows: 1. Significant negative correlation was found between bond strengths and micro leakage values. Hence, higher bond strengths seem to be associated with lower microleakage, and vice versa (r=-0 50, p<0.05). 2. The Enamel/Wet group showed significantly higher bond strength than Enamel/Dry one, and Dentin/Wet group showed higher strength than Dentin/Dry one (p<0.05). 3. Microleakage was significantly less ill wet bonding than in dry one at dentin (p<0.05), however, there was no significant difference between wet and dry bonding at enamel (p>0.05).

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Quality Changes during Storage of Kochujang Treated with Heat and High Hydrostatic Pressure (열과 초고압으로 처리한 고추장의 저장 중 품질 변화)

  • 임상빈;김봉오;김수현;목철균;박영서
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.4
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    • pp.611-616
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    • 2001
  • Effects of high pressure and thermal pasteurization on the survival of microorganisms and quality changes of kochujang during 120 days of storage at 37$^{\circ}C$ were investigated. Viable cell counts were 1.43$\times$10$^{6}$ CFU/g in heat-treated, and 1.56$\times$10$^3$ CFU/g in pressure-treated, and decreased up to 3 log cycle, compared with 3.78$\times$10$^{6}$ CFU/g in the untreated kochujang. Viable cell counts decreased by the storage period at 37$^{\circ}C$. Viable cell counts decreased up to 2 log cycle from 3.78$\times$10$^{6}$ to 5.43$\times$10$^4$ CFU/g in the untreated kochujang, 4 log cycle from 1.43$\times$10$^{6}$ to 3.10$\times$10$^2$ CFU/g in heat-treated after 120 days of storage, while those in pressure-treated were not detected after 90 days from the initial stage of 1.56$\times$10$^3$ CFU/g. pH decreased significantly by the storage time. Titratable acidity increased significantly during storage, and pressure-treated kochujang showed lower values than heat-treated. Amino nitrogen content decreased significantly during storage, and pressure-treated kochujang showed higher values than heat-treated and lower values than the untreated. There were no significant changes in reducing sugar and ethanol content regardless of the treatment condition and the storage period. Hunter L, a and b values decreased significantly during storage. In the untreated kochujang, the changes in color accelerated compared with heat and pressure-treated.

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Effect of Onion and Garlic Juice on the Lipid Oxidation and Quality Characteristics during the Storage of Conger Eel(Astroconger myriaster) (양파즙과 마늘즙이 붕장어의 저장 과정 중 지방산화 및 품질 특성에 미치는 영향)

  • 조희숙;박복희
    • Korean journal of food and cookery science
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    • v.16 no.2
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    • pp.135-142
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    • 2000
  • The purpose of this study was to investigate the effects of onion and garlic juice on the lipid oxidation of fish oil as antioxidants and quality characteristics of fish muscle. The samples were treated with onion and garlic juice at 5%(w/w) or 10%(w/w) of fish muscle, and stored at 4$\pm$1$\^{C}$ and -18$\pm$2$\^{C}$ for 7 and 42 days, respectively. The results of this study were as follows: Lipid oxidation in samples was measured by AV, POV and TBA value. AV and TBA values of the samples treated with 5% onion and garlic juice were lower than those treated with l0% onion and garlic juice. POV of the samples treated with onion were lower than those treated with garlic juice. Lightness and yellowness of the sample were the highest in 10% onion and garlic juice-treated ones. The score of overall quality in sensory evaluation was the highest in the samples treated with onion juice stored at 4$\pm$1$\^{C}$.

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Effect of Low Storage Temperature on Quality of Fresh Ginseng (저온저장 온도가 수삼의 품질에 미치는 영향)

  • Kim, Hee-Su;Kim, Gun-Hee;Kim, Dong-Man
    • Food Science and Preservation
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    • v.18 no.4
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    • pp.459-466
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    • 2011
  • To investigate optimum temperature for storage of fresh ginseng (Panax ginseng C. A. Meyer), the quality of the ginseng was compared during its storage at $-3^{\circ}C$, $-1.5^{\circ}C$ and $0^{\circ}C$. The deterioration rate of fresh ginseng stored at $-3^{\circ}C$ was the lowest for 8 weeks after storage. The rate was rapidly increased after that time and the rate at $-3^{\circ}C$ was higher than that of fresh ginseng stored at $-1.5^{\circ}C$ or $0^{\circ}C$ after the 12th week of storage. The deterioration severity of the fresh ginseng stored at $0^{\circ}C$ was much higher than that of the ginseng stored at $-1.5^{\circ}C$ and $-3^{\circ}C$. The weight loss of fresh ginseng ranged from 0.7---- to 1.6---- after 16th week; it was the lowest in the ginseng stored at $-1.5^{\circ}C$ and similar in fresh ginseng stored at $0^{\circ}C$ and $-3^{\circ}C$. The number of viable cells and molds in the fresh ginseng stored at $-3^{\circ}C$ was smaller than the fresh ginseng that was stored at other temperatures for 12 weeks, but did not differ with different storage temperatures after the 14th week of storage. The surface color of the fresh ginseng at $0^{\circ}C$ or $-1.5^{\circ}C$ was changed little while the discoloration of fresh ginseng at $-3^{\circ}C$ was relatively great. The electrolytic leakage from the rhizome of the fresh ginseng stored at $-3^{\circ}C$ was higher than that of the rhizome stored at $-1.5^{\circ}C$ and $0^{\circ}C$. The overall sensory quality of the fresh ginseng dropped below 3.0 in the S-point scale after the 10th week of storage at $-3^{\circ}C$ and after the 14th week of storage at $-1.5^{\circ}C$ and $0^{\circ}C$ (p<0.05).

Quality Characteristics of Treated with Mild Heat and Minced Ginger during Storage (열처리 조건에 따른 다진생강의 저장 중 품질특성)

  • Kim, Hee-Su;Choi, Jeong-Hee;Lee, Ho-Joon;Jeong, Moon-Cheol;Kim, Byung-Sam;Kim, Dong-Man
    • Food Science and Preservation
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    • v.17 no.6
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    • pp.784-792
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    • 2010
  • Mild heat treatment was applied to ginger rhizomes to achieve shelf-life extension for fresh minced ginger. The rhizomes were treated at 45, 50, 55, or $60^{\circ}C$ for different periods of time, minced, and stored at $10^{\circ}C$ for 9 days. Microbial levels in minced fresh ginger decreased with increases in temperature and duration of heat treatment. The non-treated and treated samples did not significantly differ in color at the initial stage of storage. Changes in color were detected after 3 days, and accelerated after that time. The ${\Delta}E$ value of control samples reached 12.42, whereas that of treated samples (except when $45^{\circ}C$ was applied for 60 min) ranged from 7.67 to 10.96, after 9 days. There was no significant difference in initial pH value between control (pH 6.09) and treated (pH 6,046.20) samples. The pH of control samples increased to 8.02 after 9 days, whereas pH values of samples treated at $50^{\circ}C$ and $60^{\circ}C$ ranged from pH 6.807.83 after 9 days. The percentage of control drip was 25.65% at the initial stage of storage, which was lower than those of treated samples. Drip increased to 38.63% in the control and to 34.20~38.44% in treated samples after 9 days. The sensory characteristics of the control samples were similar to those of treated samples at the initial stage of storage. After 6 days, the control and some treated samples developed off-flavors and discoloration. However, samples treated at $50^{\circ}C$ for 60 min retained favorable quality characteristics for 9 days after storage.

Current Research Trend of Postharvest Technology for Chrysanthemum (국화 수확 후 관리기술의 최근 연구 동향)

  • Kim, Su-Jeong;Lee, Seung-Koo;Kim, Ki-Sun
    • Korean Journal of Plant Resources
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    • v.25 no.1
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    • pp.156-168
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    • 2012
  • Chrysanthemum is a cut flower species that normally lasts for 1 to 2 weeks, in some cases 3-4 weeks. This has been attributed to low ethylene production during senescence. Reduction in cut flower quality has been attributed to the formation of air embolisms that partially or completely blocks the water transport from the vase solution to the rest of the cut flower stem, increasing hydraulic resistance which may cause severe water stress, yellowing, wilting of leaf, and chlorophyll degradation. Standard type chrysanthemum can be harvested when buds were still tightly closed and then fully opened with the simple bud-opening solution. Standard type chrysanthemum can also be harvested when the minimum size of the inflorescence is about 5-6 cm bud which opened into the first flower full-sized flower. While spray varieties can be harvested when 2-4 most mature flowers have opened (40% opening). Cut flowers are sorted by stem length, weight, condition, and so on. Standard chrysanthemum is 80 cm length for standard type and 70cm for spray type. Pre-treatment with a STS, plant regulator such as GA, BA, 1-MCP, chrysal, germicide, and sucrose, significantly improved the vase life and quality of cut flowers. It is well established that vase solutions containing sugar can improve the vase life of cut chrysanthemum. Chrysanthemum is normally packed in standard horizontal fiberboard boxes. Chrysanthemum should normally be stored at $5{\sim}7^{\circ}C$. Precooling resulted in reduction in respiration, decomposition, and transpiration activities as well as decoloration retardation. There was significant difference between "wet" storage in 3 weeks and "dry" storage in 2 weeks. In separate pulsing solution trials, various germicides were tested, as well as PGRs to maintain the green color of leaves and turgidity. Prolonging vase life was attained with the application of optimal solution such as HQS, $AgNO_3$, GA, BA and sucrose. This also retarded senescence in leaves of cut flower stems. Fresh cut chrysanthemum can be transported using a refrigerated van with $5{\sim}7^{\circ}C$. Increasing consumption and usage of cut chrysanthemum of various cultivars would require efficient transport system, and effective information exchange among producer, wholesaler, and consumer.

Chemical and Optical Absorption Spectroscopic Study of Colored Tourmalines (유색 전기석의 화학적 및 광학흡수 분광학적 연구)

  • Kim, Hee-Jong;Kim, Soo-Jin
    • Journal of the Mineralogical Society of Korea
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    • v.6 no.1
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    • pp.1-16
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    • 1993
  • The chemical and optical absorption spectroscopic characters of pink and colorless tourmalines from San Diego mine in California, U.S.A., blue/green tourmalines from anonymous mine, Brazil, and brownis black tourmalines from Uncheon and Haksan mines in Korea have been studied using X-ray diffractometer, electron microprobe, optical absorption spectroscopy, and heat treatment. Least-squares refinements give unit cell diminsions : a = 15.96-16.01 ${\AA}$, c = 7.15-7.16 ${\AA}$ for the brownish black tourmalines, a = 15.82 - 15.87 ${\AA}$, c = 7.09 - 7.10 ${\AA}$ for pink tourmalines, and a = 15.88 - 15.94 ${\AA}$, c = 7.12 - 7.15 ${\AA}$ for blue green tourmalines. The colors of tourmalines are responsible for the transition elements. The pink color is attributed to the $Mn^{3+}$ ions, the blue-green to $Fe^{2+}$ and $Mn^{2+}$, bluish green to $Cu^{2+}$, and the brownish black to $Fe^{2+}$, $Fe^{2+}$ - $Fe^{3+}$, and $Fe^{2+}$ - $Ti^{4+}$. The $Mn^{3+}$ ions of pink color tourmalines are stabilized in the Y sites compressed along the O(1)H-O(3)H axis by Jahn-Teller distortion. Heating removes the pink or red component from tourmalines, producing the colorless stones from the pink and red ones. The bluish green samples change into the greenish blue ones and a certain yellowish green samples change into the light green ones by heat treatment. In the elbaite-schorl series, the concentration of Fe and Mn are variable depending on the color zones. The green zone is characterrized by the high content of Fe and Mn are variable depending on the color zones. The green zone is characterized by the high content of Fe, whereas the pink zone by the high content of Mn. Mn increases in deep yellow zone compared with yellow or colorless zones.

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Floral Studies on Korean Wood-rotting Fungi (II) -on the flora of the Aphyllophorales(Basidiomycotina)- (한국산(韓國産) 목재부후균류(木材腐朽菌類)의 분포상(分布相)에 대한 연구(硏究) (II) -담자균류(擔子菌類) 민주름버섯목(目)의 분포(分布)에 대하여-)

  • Jung, Hack-Sung
    • The Korean Journal of Mycology
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    • v.22 no.1
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    • pp.62-99
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    • 1994
  • The fungal flora of Korean wood-rotting fungi were studied for two years from March of 1990 to February of 1992. Fresh fungi were collected from national parks, local areas, and islands throughout the country. Fleshy fungi of the Aphyllophorales were identified through specimen examination and literature studies. Total 217 species and 1 variety were counted, among which Aleurodiscus cerussatus, Botryobasidium obtusisporum, Ceraceomyces cystidiatus, Erythricium hypnophilum, Grandinia crustosa, Grandinia spathulata, Hyphoderma praetermissum, Hyphoderma roseocremeum, Hypochnicium bombycinum, Hypochnicium detriticum, Hypochnicium lundellii, Laeticorticium roseum, Mycoacia fuscoatra, Peniophora incarnata, Phanerochaete avellanea, Phanerochaete filamentosa, Phanerochaete martelliana, Phlebia lilascens, and Trechispora vaga under the Corticiaceae, Chondrostereum purpureum and Cystostereum subabruptum under the Stereaceae, Tomentella pilosa under the Thelephoraceae, Asterostroma laxum, Hymenochaete cruenta, Hymenochaete fuliginosa, Hymenochaete tabacina, Inonotus radiatus, and Phellinus pomaceus under the Hymenochaetaceae, Antrodia crassa, Antrodia serialis, Ceriporia reticulata, Oligoporus balsameus, Oligoporus guttulatus, Oxyporus cuneatus, Rigidoporus microporus, and Trichaptum laricinum under the Polyporaceae, total 36 species were confirmed as unrecorded species to Korea and are registered here with Korean names and English descriptions.

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