• Title/Summary/Keyword: 손상개시

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Durability Analysis and Development of Probability-Based Carbonation Prediction Model in Concrete Structure (콘크리트 구조물의 확률론적 탄산화 예측 모델 개발 및 내구성 해석)

  • Jung, Hyunjun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.4A
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    • pp.343-352
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    • 2010
  • Recently, many researchers have been carried out to estimate more controlled service life and long-term performance of carbonated concrete structures. Durability analysis and design based on probability have been induced to new concrete structures for design. This paper provides a carbonation prediction model based on the Fick's 1st law of diffusion using statistic data of carbonated concrete structures and the probabilistic analysis of the durability performance has been carried out by using a Bayes' theorem. The influence of concerned design parameters such as $CO_2$ diffusion coefficient, atmospheric $CO_2$ concentration, absorption quantity of $CO_2$ and the degree of hydration was investigated. Using a monitoring data, this model which was based on probabilistic approach was predicted a carbonation depth and a remaining service life at a variety of environmental concrete structures. Form the result, the application method using a realistic carbonation prediction model can be to estimate erosion-open-time, controlled durability and to determine a making decision for suitable repair and maintenance of carbonated concrete structures.

Antioxidant Enzyme Activity and Cell Membrane Stability of Korean Bermudagrass Genotypes Different in Ploidy at Dormant Stage (배수성이 다른 자생 버뮤다그래스의 휴면 전후 항산화 효소활성 및 세포막 안정성 변화)

  • Lee, Geung-Joo;Lee, Hye-Jung;Ma, Ki-Yoon;Jeon, Young-Ju;Kim, In-Kyung
    • Asian Journal of Turfgrass Science
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    • v.25 no.1
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    • pp.17-21
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    • 2011
  • Korean bennudagrass collections showed diverse genetic variations in their morphology, growth habit, and cytological aspects. Chromosome number and nuclear DNA content of the bennudagrasses indicated a ploidy level ranging from triploid (2n=3x) to hexaploid (2n=6x). In this study, we investigated the different responses of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase) and cell membrane stability of those bennudagrass cytotypes to lower temperature and shorter day length, which meets a dormant induction in Korea. All the antioxidant enzymes were found to be higher during dormant stage, while the heme-containing catalase which converts hydrogen peroxide ($H_2O_2$) to water and oxygen molecules was activated before dormant initiation in the three cytotypes except for hexaploid bennudagrass. The triploid and tetraploid which exhibited relatively finer leaves and a rapid establishment speed were found to show increased activities of superoxide dismutase and peroxidase enzyme. The malondialdehyde(MDA) which is a product of lipid peroxidation in the cell membrane damaged by the hydroxyl radical was increased in all cytotypes as temperature declined, and tri- and tetraploids which had more protective antioxidant enzymes demonstrated a significantly lower MDA production. Similarly electrolyte leakage was higher in penta- and hexaploidy, seemingly more damage to cell membrane when low temperature was implemented. Results indicated that antioxidant responses of different cytotypes were genetically specific, which needs to be investigated the relevance with the low temperature tolerance in the bermudagrass further at the molecular level.

Evaluation of the Photoprotective Effect of Dongchongxiacao ($Paecilomyces$ $japonica$) Extract against Ultraviolet Radiation-induced Skin Wrinkling and Cancer (자외선 유도 피부주름 및 암발생에 대한 누에동충하초($Paecilomyces$ $japonica$)의 보호효과 평가)

  • Lee, Hae-June;Moon, Chang-Jong;Kim, Jong-Choon;Jung, U-Hee;Jo, Sung-Kee;Jang, Jong-Sik;Kim, Sung-Ho
    • Journal of Radiation Protection and Research
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    • v.37 no.1
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    • pp.50-55
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    • 2012
  • To evaluate the ability of Dongchongxiacao ($Paecilomyces$ $japonica$) extract (PJE) to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and PJE-treated mice exposed chronically to ultraviolet (UV) were examined. The skin of the UV-irradiated mice showed characteristic signs of photoaging, such as deep wrinkles across the back. PJE-treated mice showed a significantly decreased wrinkling score. By the 22nd week, 88.9% (i.p. with saline) or 44.4% (topical administration with cream base) of the UV-irradiated mice developed at least one tumor. PJE delayed tumor onset significantly. PJE (i.p.) was also effective in reducing the occurrence of UV radiation-induced skin tumors and reduced the number of tumors per mouse. After 22 weeks of treatment, 80.0% (i.p.) and 75.0% (topical) of the mice treated with PJE were tumor-free. Tumor multiplicity was reduced by 96.2% (i.p.) in the PJE treated groups. It is noted that skin that is chronically exposed to UV is subject to photoaging and photocarcinogenesis and regular use of PJE would prevent these photodamaging effects of UV.

Physicochemical Properties of Various Milled Rice Flours (제분방법별 쌀가루의 이화학적 특성)

  • Park, Yong-Kon;Seog, Ho-Moon;Nam, Young-Jung;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.20 no.4
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    • pp.504-510
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    • 1988
  • The physicochemical properties of rice flours which were obtained by dry milling(blade, hammer, test and micro mill) and wet & dry milling (roller & micro mill) were investigated. The resulting flour particle sizes were reduced in the order that of blade, hammer, test, micro and roller & micro mill. Scanning electron microscopic examination showed that the starch granules were freed from the imbedding matrix as the particles became finer. The test-milled flour had the hightest levels of starch damage, maltose value and hot-water soluble amylose content, and the blade-milled flour showed the lowest levels. Amylograph viscosity and gelatinization temperature of the flours decreased as the particles became finer, and the addition of $Hg^{+2}$ increased the peak viscosity of the dry-milled flour pastes, whereas the wet & dry-milled flour did not show any changes. The blue values and ${\lambda}$max values of the iodine complex of the cold-water extractable ${\alpha}-D-glucan$ from flours were in the range of 0.023-0.029 and 518-522nm, respectively, indicating these materials were shown to be mainly composed of amylopectin-like polymer.

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Quality Attributes of Frozen Dough Mixed with Milk Protein-Polysaccharide Materials (우유단백질과 다당류 혼합물을 첨가한 냉동반죽의 품질 특성)

  • Shon, Jin-Han;Jeung, Jeung-Il;Oh, Deog-Hwan;Kim, Jai-Moung;Eun, Jong-Bang
    • Food Science and Preservation
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    • v.16 no.4
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    • pp.518-524
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    • 2009
  • The quality attributes of frozen dough mixed with milk proteins (casein: C and whey protein: W) and polysaccharides (sodium alginate: A and ${\kappa}-carrageenan:$ K), and with 1.6% (w/w) wheat flour, were investigated to improve the quality of dough. Addition of milk protein-polysaccharide mixtures increased water absorption, as assessed by farinography, compared with control material. Dough prepared with CA and WA mixtures showed longer development times and increased valorimeter values compared with control samples. However, addition of milk protein-polysaccharide mixtures decreased dough stability, elasticity, and strength. Gelatinization temperature and the temperature at maximum viscosity, as measured by amylography, increased on addition of milk protein-polysaccharide mixtures, but the maximum viscosity decreased compared with control samples. The control showed a lower dough volume than did dough prepared with CA and WA mixtures. These results indicate that addition of milk protein-polysaccharide mixtures, especially CA and WA, improved the quality of frozen dough,and could be useful to prevent bread becoming stale.

Induction of Tumor Suppressor Gene p53-dependent Apoptosis by Sanguinarine in HCT116 Human Colorectal Cancer Cells (결장암세포에서 sanguinarine에 의한 종양억제 유전자 p53 의존적 apoptosis 유도)

  • Choi, Yung Hyun
    • Journal of Life Science
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    • v.31 no.4
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    • pp.400-409
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    • 2021
  • Sanguinarine, a natural benzophenanthridine alkaloid, has been considered a potential therapeutic target for the treatment of cancer because it can induce apoptosis in human cancer cells; however, the underlying mechanisms of action still remain unclear. Tumor suppressor p53 deletion or mutation is an important reason for the resistance of colorectal cancer cells to anticancer agents. Therefore, in the present study, the role of p53 during apoptosis induced by sanguinarine was investigated in p53wild type (WT, p53+/+) and p53null (p53+/+) HCT116 colon carcinoma cells. Sanguinarine significantly caused greater reductions in cell viability in HCT116 (p53+/+) cells than in HCT116 (p53-/-) cells. Consistently, sanguinarine promoted more DNA damage and apoptosis in HCT116 (p53+/+) cells than in HCT116 (p53-/-) cells while increasing the expression of p53 and cyclin-dependent kinase inhibitor p21WAF1/CIP1. Sanguinarine increased the activity of caspase-8 and caspase-9, which are involved in the initiation of extrinsic and intrinsic apoptosis pathways, respectively, and it activated caspase-3, a typical effect caspase, in HCT116 (p53+/+) cells. Sanguinarine also increased the generation of reactive oxygen species (ROS), and the Bax/Bcl-2 ratio, while destroying the integrity of mitochondria in HCT116 (p53+/+) cells, but not in HCT116 (p53-/-) cells. Overall, the results indicate that sanguinarine induced p53-dependent apoptosis through ROS-mediated activation of extrinsic and intrinsic apoptotic pathways in HCT116 colorectal cancer cells.

Increased Apoptotic Efficacy of Decitabine in Combination with an NF-kappaB Inhibitor in Human Gastric Cancer AGS Cells (핵산합성 억제제인 decitabine과 NF-κB 활성 저해제인 PDTC의 병용 처리에 의한 인체 위암세포사멸 효과 증진)

  • Choe, Won Kyung;Choi, Yung Hyun
    • Journal of Life Science
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    • v.28 no.11
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    • pp.1268-1276
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    • 2018
  • The cytidine analog decitabine (DEC) acts as a nucleic acid synthesis inhibitor, whereas ammonium pyrrolidine dithiocarbamate (PDTC) is an inhibitor of nuclear factor-${\kappa}B$. The aim of this study was to investigate the possible synergistic inhibitory effect of these two inhibitors on proliferation of human gastric cancer AGS cells. The inhibitory effect of PDTC on AGS cell proliferation was significantly increased by DEC in a concentration-dependent manner, and this inhibition was associated with cell cycle arrest at the G2/M phase and the induction of apoptosis. This induction of apoptosis by the co-treatment with PDTC and DEC was related to the induction of DNA damage, as assessed by H2AX phosphorylation. Further studies demonstrated that co-treatment with PDTC and DEC induced the disruption of mitochondrial membrane potential, increased the generation of intracellular reactive oxygen species (ROS) and the expression of pro-apoptotic Bax, and down-regulated the expression of anti-apoptotic Bcl-2, ultimately resulting in the release of cytochrome c from the mitochondria into the cytoplasm. Co-treatment with PDTC and DEC also activated caspase-8 and caspase-9, which are representative caspases of the extrinsic and intrinsic apoptosis pathways. Co-treatment also activated caspase-3, which was accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Taken together, these data clearly indicated that co-treatment with PDTC and DEC suppressed the proliferation of AGS cells by increasing DNA damage and activating the ROS-mediated extrinsic and intrinsic apoptosis pathways.

A Study on Seismic Restraint of Korean Type Building Gas Piping (한국형 건축물 가스 배관의 내진 고정장치에 관한 연구)

  • Lim, Geon-Tae;Lim, Sang-Ho
    • Industry Promotion Research
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    • v.4 no.1
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    • pp.11-20
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    • 2019
  • This study relates to a fixing device for gas piping installed in a building such as an apartment or a building. The gas piping is fixed to the inside of the housing so as to buffer the gas piping in all directions, thereby relieving vibration caused by an earthquake or an impact, Disclosed is an earthquake-proof fixing device for a gas pipeline that can minimize damages caused by damage to an earthquake and a gas pipeline by preventing damage and breakage. An apparatus for fixing a gas pipe to a bracket provided on a wall or a wall of a building, the apparatus comprising: a housing coupled to a wall or a bracket and coupled to the inside of the housing; a gas pipe penetrating through the housing to fix the gas pipe; The first plate spring includes a first plate spring formed with a plurality of concave-convex portions that are elastically supported in four directions. The first plate spring is screwed to the front surface or the rear surface of the housing. The lower plate is coupled to one end and the other end, And a pair of first adjusting screws for adjusting the elastic force of the spring. Through this study, damage and damage of gas piping due to earthquake or impact can be minimized.

Physicochemical properties of powdered, soft and hard type rice flour by different milling methods (제분방법에 따른 분질, 연질 및 경질미 가루의 이화학적 특성)

  • Choi, Ok Ja;Jung, Hee Nam;Shim, Ki Hoon
    • Food Science and Preservation
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    • v.22 no.2
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    • pp.174-181
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    • 2015
  • This study investigated the physicochemical properties of three different types of rice flour prepared via dry and wet milling. The powder, soft, and hard-types of rice flour were Suwon No. 542, Suwon No. 541, and Unbong No. 30, respectively. The analysis of the proximate compositions of the different types of rice flour showed that their moisture content was 7.03~7.99%, their crude protein was 7.94~8.35%, their crude lipid was 0.71~1.49% and their crude ash was 0.25~0.82%. For the Hunter's color values, the L value was highest in the wet-milled rice flour, the a value was highest in the dry-milled rice flour, and the b value was highest in the dry-milled rice flour. All the samples showed distinctive rice starch particles in the particle analysis using scanning electron microscope. The dry-milled rice flour showed the greatest amount of irregular particles and the coarsest texture. The water absorption and water solubility indices were higher in the wet-milled soft- and hard-type rice flour. The crystallinities of the samples by X-ray diffractography were all A-type, but the crystallinity of the dry-milled hard-type rice flour was higher in diffraction degree. For the amylogram properties, the wet-milled soft-type rice flour showed the highest maximum viscosity, breakdown and setback. In the meanwhile, the dry-milled soft-type rice flour showed the highest initial pasting temperature, onset, peak, and end temperatures despite of the reverse enthalpy.

Beach Resort Formation and Development Processes by Fabric Construction in an Island Environment (구조물 축조에 의한 도서지역 해수욕장의 발달과정에 관한 연구 -완도군 보길면 지역을 사례로-)

  • 박의준;황철수
    • Journal of the Korean Geographical Society
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    • v.36 no.4
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    • pp.474-482
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    • 2001
  • The purpose of this study is to investigate the formation and development processes of beach resort by fabric construction in a island environment. The results are as follows. (1) The research area(Tong-ri beach, Bokil-myon, Chollanam-do)has been transformed to belch by sedimentary environmental change since latter half of 1800's. (2) The mean slope of beach face is 0.96°, and the difference of attitude between beach and mud flat face is 75cm. (3) The mean particle size of beach surface sediment is 3.53$\Phi$. This value is very finer than that of any other beach in Korea peninsula. But its value is coarser than that of mud flat surface sediment. (4) The particle size distribution of core sediment is become changed to fine particle in 70cm depth. This value is corresponded to difference of altitude between beach face and mud flat face. (5) The analysis of aerial photographs after 1970 indicates that sedimentation process was not brisked since 1970's. Consequently, the research ares has been developed by sedimentary environmental change for sea-level rise effect and wave height energy rise effect.

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