• 제목/요약/키워드: materials science

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Selection of Virulent Isolates of Fusarium circinatum and Investigation of Pitch Canker Severity of Pinus rigida and P. rigida × P. taeda Seed Orchards in Jeju Island (제주도(濟州道) 리기다 및 리기테다 채종원(採種園)에서 푸사리움가지마름병 피해도(被害度) 조사(調査) 및 병원성(病原性) 균주선발(菌株選拔))

  • Woo, Kwan-Soo;Kim, Young-Joung;Kim, Tae-Su;Lee, Seong-Kyu
    • Journal of Korean Society of Forest Science
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    • v.94 no.6
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    • pp.402-409
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    • 2005
  • This study was undertaken to compare and estimate the severity of pitch canker of individual trees of Pinus rigida and Pinus rigida ${\times}$ P. taeda in two seed orchards in Jeju island, in which the orchards have been damaged by the pitch canker for seven years. Wind-pollinated two-year-old seedlings of P. rigida and P. rigida ${\times}$ P. taeda, in which the seedlings of P. rigida ${\times}$ P. taeda were from seeds of phenotypically selected, uninfected(but untested) trees, were inoculated with the pathogenic fungus, Fusarium circinatum, isolated from P. rigida and P. thunbergii. The virulence of the isolates was also identified. Statistically significant difference was found in 'stem cankers'(SC; ${\chi}^2=7.76$, P=0.05) among 4 plantations of P. rigida ${\times}$ P. taeda of two seed orchards. P. rigida was higher in 'top kill' (TK) and 'branch tip symptoms' (BT) than those of P. rigida ${\times}$ P. taeda. In artificial inoculation tests, mortality of the seedlings from the resistant candidates was 14% higher than that of the seedlings from the susceptible candidates. This result may becaused by unknown pollen trees and/or candidate tree selection based only on phenotype. Two of five fungal isolates, C-6-L(9) and C-6-L(19), showed significantly higher mortality (68% and 60%, respectively) than others, suggesting that these isolates can be used as virulent isolates for a mass artificial inoculation. Resistance candidate seedlings that were selected from this study can be utilized as useful materials for fundamental studies of genetics and biochemistry to breed resistance varieties to pitch canker.

Analysis on the Components of the Vitex rotundifolia Fruit and Stem (순비기나무(Vitex rotundifolia) 열매와 줄기의 함유성분 분석)

  • Lee, Yang-Suk;Joo, Eun-Young;Kim, Nam-Woo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.2
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    • pp.184-189
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    • 2008
  • This study was conducted to analyze components of the fruit and stem of Vitex rotundifolia as part of a study on the nutritional and functional materials, and the development of a functional food. General components of V. rotundifolia fruit are moisture 12.92%, carbohydrate 78.67%, crude protein 3.22%, crude fat 1.73% and 3.46% crude ash. V. rotundifolia stem was moisture 11.30%, carbohydrate 80.87%, crude protein 4.78%, crude fat 0.64 % and 2.41% crude ash. The content of V. rotundifolia reducing sugar was 646.07 mg% (fruit) and 1,547.97 mg% (stem). The total amount of free sugar was fruit 5.66 mg% and stem 90.79 mg%. The content of soluble protein was 3,268.12 mg% in fruit and 4,927.55 mg% in stem. The polyphenol compound content was 608.06 mg% and 808.06 mg%, respectively. Total amount of hydrolyzed amino acid of V. rotundifolia fruit and stem were 3,095.75 mg% and 2,135.84 mg%, while that of free amino acid of fruit and stem were 79.99 mg%, 81.20 mg%, among which cysteine (2,010.82 mg%) was the highest in the V. rotundifolia fruit. In the results of mineral analysis, the content of K was the highest in fruit (2,184.00 mg%) and stem (1,469.20 mg%).

Quality Changes of Fresh-Cut Leafy and Condiment Vegetables during Refrigerated Storage (신선편이 엽채류 및 조미채소류의 냉장저장 중 품질변화)

  • Kim, Su-Jin;Sun, Shih-Hui;Kim, Gi-Chang;Kim, Haeng-Ran;Yoon, Ki-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.8
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    • pp.1141-1149
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    • 2011
  • The objective of this study was to analyze quality changes during storage of fresh-cut produce (leafy vegetables and condiment vegetables) as a function of packaging and storage temperature. Fresh-cut produce was washed using a three step cleaning process and was packed in vacuum packaging (green onion, hot pepper, onion, baechu) and perforated film packaging (buchu and perilla leaf). The effects of packaging method and storage temperature on quality of fresh-cut produce were determined by analyzing total plate counts, E. coli, coliform groups, moisture content, pH, Aw, surface color, and exterior quality during storage at 4 and 10$^{\circ}C$. According to the results, surface color change and microbial growth were delayed during storage at 4$^{\circ}C$. Additionally, E. coli was not detected during storage. Generally, moisture content decreased in the perforated film packaging. Changes in surface quality such as skin browning, softening of tissue and chlorosis at 4$^{\circ}C$ were inhibited, whereas rapid vacuum annealing and changes in color and flavor were observed in the sample stored at 10$^{\circ}C$. The result indicated that overall quality of the fresh-cut produce at 4$^{\circ}C$ was well maintained. The perforation in packing materials did not significantly increase the number of microorganisms on buchu and perilla leaf. The proper packaging methods and temperature may beneficial effect on microbial safety, quality and thus result in longer shelf-life fresh-cut vegetables during distribution.

Effect of Fermented Cucumber Beverage on Ethanol Metabolism and Antioxidant Activity in Ethanol-treated Rats (오이 발효음료가 만성적으로 에탄올을 급여한 흰쥐의 에탄올 대사와 항산화방어계에 미치는 영향)

  • Lee, Hae-In;Seo, Kwon-Il;Lee, Jin;Lee, Jeom-Sook;Hong, Sung-Min;Lee, Ju-Hye;Kim, Myung-Joo;Lee, Mi-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.8
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    • pp.1099-1106
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    • 2011
  • Cucumber fermentation has been used as a means of preservation. This study was performed to investigate the effects of fermented cucumber beverage (CF) containing beneficial materials for an ethanol hangover based on Hovenia dulcis (SKM) on ethanol-induced hepatotoxicity. Male Sprague-Dawley rats were randomly divided into three groups: ethanol control, ethanol plus SKM, and ethanol plus CF+SKM. SKM or CF+SKM was orally administered at a dose of 7 mL/kg body weight once per day for 5 weeks. Control rats were given an equal amount of water. CF+SKM significantly lowered plasma ethanol levels, whereas SKM tended to decrease the levels compared to the control. Both SKM and CF+SKM significantly lowered the plasma acetaldehyde levels and serum transaminase activities compared to those in the control. SKM and CF+SKM did not affect hepatic alcohol dehydrogenase activity; however, it significantly inhibited cytochrome P450 2E1 (CYP2E1) activity. Hepatic aldehyde dehydrogenase (ALDH) activity was significantly higher in the SKM and CF+SKM groups than that in the control group. Plasma acetaldehyde concentration was significantly correlated with hepatic CYP2E1 (r=0.566, p<0.01) activity and ALDH (r=-0.564, p<0.01) activity. Hepatic superoxide dismutase and catalase activities as well as glutathione content increased with the SKM and CF+SKM administration, whereas lipid peroxide content decreased significantly. Furthermore, SKM and CF+SKM lowered plasma and hepatic lipid content and lipid droplets compared to those in the control group. These results indicate that SKM and CF+SKM exhibit hepatoprotective properties partly by inhibiting CYP2E1 activity, enhancing ALDH activity and stimulating the antioxidant defense systems in ethanol-treated rats.

Antioxidative Activities of Temperature-stepwise Water Extracts from Inonotus obliquus (차가버섯의 온도단계별 물추출물의 항산화성 비교)

  • Lee, Sang-Ok;Kim, Min-Jeong;Kim, Dong-Gyun;Choi, Hyun-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.2
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    • pp.139-147
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    • 2005
  • The efficacy of extraction from Inonotus obliquus was examined from the points of antioxidative characteristics and some antioxidative compounds. To enhance the efficient extraction for the effective components from Inonotus obliquus, temperature-stepwise water extraction method was applied. Temperature-stepwise water extracts were prepared for 8 hrs as follows: the first extract at 8$0^{\circ}C$, the second extract from the residue of the first extract at 10$0^{\circ}C$, and the third extract from the residue of the second extract at 12$0^{\circ}C$. Antioxidativeactivities were determined by electron-donating ability of DPPR - free radical, scavenging ability of ABTS$.$$^{+}$radical cation, and by inhibiting ability of linoleic acid autoxidation. In results, the first extract showed the least antioxidant capacity, and the third extract showed the highest antioxidant capacity. The third extract also had the greatest amounts of phenolic compounds and flavonoids. Amounts of phenolic compound from each extract were almost proportional to the radical scavenging activities and linoleic acid autoxidation inhibiting ability (r=0.960∼0.980, regression analysis). Furthermore, the effect of the pooled extract of all three extractions of Inonotus obliquus on the lipid peroxidation reacted with active oxygen species (KO$_2$, $H_2O$$_2$, $.$OH) and metals (Fe$^{2+}$, CU$^{2+}$) was evaluated by measuring the formation of thiobarbituric acid reactive substances (TBARS). The pooled Inonotus obliquus extracts lowered the amounts of TBARS formed by all of the active oxygen species and metals. Especially, these lowering effects were pronounced in the reaction with $.$OH and Fe$^{2+}$. These results suggest that the pooled temperature-stepwise extract from Inonotus obliquus could be potential functional materials to reduce the oxidation of lipids and other compounds induced by free radicals.adicals.

Isolation and characterization of human dental tissue-derived stem cells in the impacted wisdom teeth: comparison of dental follicle, dental pulp, and root apical papilla-derived cells (미성숙 매복지치의 치낭, 치수, 치근유두 조직에서 다능성 줄기세포의 분리와 특성화에 대한 연구)

  • Song, Jung-Ho;Park, Bong-Wook;Byun, June-Ho;Kang, Eun-Ju;Rho, Gyu-Jin;Shin, Sang-Hun;Kim, Uk-Kyu;Kim, Jong-Ryoul
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.36 no.3
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    • pp.186-196
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    • 2010
  • Introduction: The first aim of this study was to isolate the dental tissue-derived stem cells from the dental follicle (DF), dental pulp (DP), and root apical papilla (RAP) of the extracted wisdom teeth. Second was to evaluate their characterization with the expressions of transcription factors and cell surface markers. Finally, their ability of the in vitro multi-lineage differentiations into osteogenic and adipogenic cells were compared, respectively. Materials and Methods: Dental tissues, including dental follicle, dental pulp, and root apical papilla, were separated in the extracted wisdom teeth. These three dental tissues were cultured in Dulbecco’s modified Eagle’s medium (DMEM) with supplements, respectively. After passage 3, the homogeneous shaped dental tissue-derived cells were analyzed the expression of transcription factors (Oct-4, Nanog and Sox-2) and cell surface markers (CD44, CD90 and CD105) with reverse transcription polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS) analysis. In order to evaluate in vitro multi-lineage differentiations, the culture media were changed to the osteogenic and adipogenic induction mediums when the dental tissue-derived cells reached to passage 3. The characteristics of these three dental tissue-derived cells were compared with immunohistochemistry. Results: During primary culture, heterogenous and colony formatted dental tissue-derived cells were observed in the culture plates. After passage 2 or 3, homogenous spindle-like cells were observed in all culture plates. Transcription factors and mesenchymal stem cell markers were positively observed in all three types of dental tissue-derived cells. However, the quantity of expressed transcription factors was most large in RAP-derived cells. In all three types of dental tissue-derived cells, osteogenic and adipogenic differentiations were observed after treatment of specific induction media. In vitro adipogenic differentiation was similar among these three types of cells. In vitro osteogenic differentiation was most strongly and frequently observed in the RAP-derived cells, whereas rarely osteogenic differentiation was observed in the DP-derived cells. Conclusion: These findings suggest that three types of human dental tissue-derived cells from extracted wisdom teeth were multipotent mesenchymal stem cells, have the properties of multi-lineage differentiations. Especially, stem cells from root apical papilla (SCAP) have much advantage in osteogenic differentiation, whereas dental follicle cells (DFCs) have a characteristic of easy adipogenic differentiation.

Studies on Creep Behavior for Rice Stalks (벼줄기의 크리이프 거동(擧動)에 관한 연구)

  • Huh, Yun Kun;Kim, Sung Rai;Lee, Sang Woo
    • Korean Journal of Agricultural Science
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    • v.22 no.1
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    • pp.1-10
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    • 1995
  • All agricultural crops and products should be cultured, harvested, handled and processed by the proper mechanical methods in the mechanized farming systems. Agricultural crops might be injured or deformed through various working stages due to static or dynamic forces of machines. Mechanical forces had to be applied with proper degrees to the agricultural crops in incoincidence with properties of crops without any damage of crops so as to increase the work efficiency qualitatively. Knowledges of mechanical properties of agricultural materials are essential to prevent of agricultural crops in relation with mechanical farming system. This study was carried out to examine and analyze the creep behavior of the rice stalk on growing and harvesting periods by mechanical model with computer measurement system in radial directional compressive force and bending force. The creep behavior of the rice stalk could be predicted precisely and its results approached closely to the measured values. The creep behaviors were increased greatly with increase of compressive force, namely, the steady state creep behavior occurred at the force less then 25N and the logarithmic creep behavior at the force bigger than 30N. The instantaneous elastic modulus $E_o$ and the retardation time ${\tau}_K$ were increased together with increase of applied forces, meanwhile the retarded elastic modulus $E_r$ and viscosity ${\eta}_v$ were decreased with increase of applied forces in mechanical model being expected the creep behavior in relation with the level of applied forces, which was well explained that the rice stalk might be visvo-elastic material. In the creep test along the stalk portion with compressive force and bending force, the intermediate portion showed greatest values and also the lower portion showed the least values, which implied that the intermediate portions of rice stalk were very weak. The steady state creep behavior occured at the intermediate portion and the upper portion in the rice stalk at the compressive force larger than 25.0N, which showed the possibility of injury due to external forces.

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Influencing factors on the final color of laminate veneer restorations with various IPS Empress Esthetic$^{(R)}$ ingots (다양한 IPS Empress Esthetic$^{(R)}$ ingot으로 제작한 laminate veneer의 최종 색조에 대한 영향)

  • Yang, Mi-Seon;Kim, Seok-Gyu
    • The Journal of Korean Academy of Prosthodontics
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    • v.49 no.4
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    • pp.308-315
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    • 2011
  • Purpose: The purpose of this study was to colorimetrically evaluate the masking effect of different opacity of ingots on the final shade of IPS Empress Esthetic$^{(R)}$ laminate veneer restorations using the CIE $L^*a^*b^*$ system. Materials and methods: Six porcelain disks of IPS Empress Esthetic$^{(R)}$ system (translucency: E 01, E 03, E 0C-1, E TC-1, E TC-2, E TC-3) were fabricated with 7 mm in diameter and 0.6 mm in thickness. Six extracted human incisors (shade: A1, A3, A4, B2, B3, C3) were used as the abutment specimens. The incisors were prepared using a diamond wheel and made with a flat labial surface on the middle 1/3. For each combination of different shades of abutments and copings, the change in color was measured with a colorimeter. CIE $L^*a^*b^*$ coordinates were recorded for each specimen. Color differences (${\Delta}E$) were calculated. Descriptive statistical analysis was done. Results: ${\Delta}E$ values were significantly affected by coping translucency and abutment shade (P<.05). The color differences (${\Delta}E$) of laminate veneers among abutments with A3, B3, C3, and A4 shade were mostly below 2.7 which was within the clinically acceptable range, while color differences between A4 and B2, A3 and B2, and A1 and A4 showed more than 2.7. Conclusion: The final color of IPS Empress Esthetic$^{(R)}$ laminate veneers were significantly influenced by translucency of the coping and shade of abutment teeth. The large value difference of abutment teeth limited the masking ability by laminate veneers.

Studies on the Development of Natural Preservatives from Natural Products (전통식품 및 천연물에서 천연보존료 개발에 관한 연구)

  • Kim, Hee-Yun;Lee, Young-Ja;Hong, Ki-Hyoung;Kwon, Yong-Kwan;Lee, Ju-Yeun;Kim, So-Hee;Ha, Sang-Chunl;Cho, Hong-Yon;Chang, Ih-Seop;Lee, Chul-Won;Kim, Kil-Saeng
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1667-1678
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    • 1999
  • Certain parts of 190 kinds of medicinal herbs and 171 kinds of original materials of food were extracted by methanol. The extracts were tested their microbial inhibition activities against several food spoilage microorganisms, Micrococcus luteus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli, Saccharomyces cerevisiae, Candida albicans, Penicillium citrinum, Aspergillus flavus and Aspergillus niger. The methanol extracts of Cornus officinalis, Evodia officinalis, Glycyrrhiza glabra, Salvia miltiorrhiza. Schizandrae fructus, Coptidis rhizoma, aroma hop and bitter hop were shown inhibitory effect on certain species of gram(+) bacteria. Aroma hop and bitter hop were shown inhibitory effect on certain species of gram(-) bacteria. The methanol extract of Salvia miltiorrhiza exhibited a strong antibacterial activities. It was purified by solvent fractionation, silicagel column chromatography, prep. TLC, prep. HPLC. The purified active substance was identified as cryptotanshinone by EIMS, $1^H-NMR,\;{13}^C-NMR$ and DEPT. Cryptotanshinone showed a strong antibacterial activity against gram positive bacteria $(MIC\;:\;3.91{\sim}62.50\;{\mu}g/mL)$. Especially, this compound was the most strong activity against Bacillus subtilis $(MIC\;:\;3.91\;{\mu}g/mL)$.

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Gel and Texture Properties of Fish-meat Gel Prepared with Pagrus major in Comparison to Different Grades of Alaska Pollock (도미를 활용하여 제조한 연제품의 겔 및 texture 특성)

  • Gao, Ya;Oh, Jung Hwan;Karadeniz, Fatih;Lee, Seul-Gi;Kim, Hyung Kwang;Kim, Se Jong;Jung, Jun Mo;Cheon, Ji Hyeon;Kong, Chang-Suk
    • Journal of Life Science
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    • v.26 no.8
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    • pp.955-962
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    • 2016
  • Fish-meat gel is an intermediate product used in a variety of surimi-based seafood. One of the most-used raw materials of fish-meat gel is Alaska Pollock due to its high-quality meat in terms of gel strength and texture. However, increasing demand for fish-meat gel, along with overexploitation of the wild catch Alaska Pollock, has put the industry in need of low-cost sustainable alternative sources for fish-meat gel. Pagrus major (PM) is a widely aquacultured fish known for having white meat that is low in fat. The current study compares the quality of fish-meat gel prepared from aquacultured PM to that of high and mid-grade Alaska Pollock fish-meat gel. Gels were compared in terms of gel strength, texture, color, and protein pattern. Results indicated that fish-meat gels prepared from PM were superior to Alaska Pollock fish-meat gels with regard to gel strength, hardness, springiness, chewiness, cutting strength, and breaking force. In addition, although not matching in quality, PM exhibited a cohesiveness, whiteness, and expressible moisture content comparable to Alaska Pollock of both grades. Protein pattern analysis also showed that PM and Alaska Pollock fish-meat gels had similar protein profiles before and after gel preparation. Therefore, P. major is suggested as a potential substitute for Alaska Pollock in fish-meat gel production.