• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.129-142
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• 1976

Optimum doses The optimum dose that may be defined as the dose below the maximum permissible dose, yet would bring about a significant storage life extension at refrigerated temperatures, varied with species of fish as well as with the postirradiation storage temperatures. Thus the dose of 0. 1 Mrad was considered to be optimum for the croaker and yellow corvenia at $0^{\circ}C$, while at $5^{\circ}C$ the dose of 0.2 Mrad would be suitable for both species. The roundnose flounder was more radiosensitive and even at the dose of 0.1 Mrad a slight irradiation odor was detected immediately after the radiation treatment. Such degree of irradiation odor disappeared upon storage, therefore, the dose of 0.1 Mrad was considered to be optimum for the roundnose flounder at both $0^{\circ}\;and\;5^{\circ}C$. Storage life extension The croaker meats irradiated at 0.1 Mrad could be held at $0^{\circ}C$ as long as 5 weeks in good acceptable conditions, while the unirradiated control became unacceptable within 2 weeks-3-4 for extension of storage life at $0^{\circ}C$. At the storage temperature of $5^{\circ}C$, the storage life of 0.2 Mrad irradiated samples was extended from less than one week to 4 weeks--4-5 fold extension. The storage life extension of 0.1 Mrad irradiated yellow corvenia at $0^{\circ}C$ was from less than 2 weeks for the unirradiated to 4 weeks-approximately a-s folds and that of 0.2 Mrad irradiated samples stored at $5^{\circ}C$ was from 5 days to 3 weeks 4-5 folds. The roundnose flounder meats irradiated at 0.1 Mrad could held at $0^{\circ}C$ for 3-4 weeks as compared to less than 1 week for the unirradiated and at $5^{\circ}C$ the storage life could be extended from less than 3 days to up to 3 weeks. Thus the storage life extension by 4-5 folds and by 6-7 folds was possible at $0^{\circ}C\;and\;5^{\circ}C$ storage, respectively. Postirradiation storage microbiology and biochemistry In general 10 fold reduction of initial microflora was realized as a result of irradiating fish samples at 0.1 Mrad. The extent of microflora reduction increased with increasing doses applied, but not proportionately dependent. The microbial growth in the irradiated was severely retarded during the subsequent storage period, lagging far behind that of the irradiated control samples except in the late storage phase, when the levels of microflora of the irradiated either approached to or rose above the levels of the unirradiated. The microbiological changes caused by irradiation was reflected in the pronounced suppression of TVB and TMA accumulation during the storage period. This suggests that irradiation treatment brought about both quantitative and qualitative changes in microflora initially present and it is reasonable to suggest that the microflora removed by irradiation in fact represent most of the flora capable of producing TVB and TMA in normal fish spoilage process.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.221-228
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• 2011

Weed control is of fundamental importance when planting horticultural crops, particularly during the establishment phase. Weeds compete for nutrients, water and light, and can severely threaten the survival and early growth of newly planted crops. Failure to control weeds represents one of the single most important factors leading to crop loss. Knowledge on the existence of the diversity of weed species in greenhouses is of our main concern in this study in order to develop a most efficient and effective weed control strategies. Sixty-two greenhouses were surveyed in 3 cities and counties of Gyeongnam area in March to October 2009 to investigate the feature of weed occurrence in polyvinyl chloride (PVC) after harvesting of the main crops. Forty-one weed species were identified and classified to 18 families which were composed of 14 annual weeds, 18 summer annual weeds and 9 perennial weeds. On the other hand, broadleaf, grasses and sedges recorded with 30, 7 and 4 weed species, respectively. Asteraceae was the most dominant weed species (9 species) noted followed by Poaceae (7 species), Cyperaceae (4 species), Caryophyllaceae and Brassicaceae (3 species respectively) and other families have 1~2 species. The dominant weed species occurred in the greenhouse based on the summed dominance ratio. These weeds were Digitaria sanguinalis, Cyperus iria, Portulaca oleracea, Rorippa islandica, Mazus japonicas, Cardamine flexousa, and Eclipta prostrata and others. Weed occurrence in the greenhouse after horticultural crops consisted of summer annuals (4 species), winter annuals (3 species), and perennial annuals (1 specie). The dominant species occurred in tilled soil based on summed dominance ratio of weeds were Cardamine flexousa (88.1%), Eclipta prostrate (57.4%) and Portulaca oleracea (55.2%). Comparison of weed occurrence was thoroughly surveyed also in which field without PVC, weed species were Portulaca oleracea (55.2), Eclipta prostrata (57.9%) and Trigonotis peduncularis (25.1%) and field with PVC, the identified weeds were Portulaca oleracea (98.75), Trigonotis peduncularis (49.1%), and Eclipta prostrata (36.8%).

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.138-159
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• 1996

There has been a tendency for Geomorphology and Climatology to be dominant in Physical Geography for 50 years in Korea. Physical Geography is concerned with the study of the totality of natural environment through the integrated approaches. But, an overall direction or a certain paradigm could not be found, because major sub-divisions of Physical Geography have been studied individually and the subjects and the approaches in studying Physical Geography are enormously diverse. A consensus of opinion could not also exist in deciding what kind of the sub-divisions should be included in the physical geography in general and how those should be summarized. Furthermore it would be considered imprudent to survey the studies of Physical Geography besides those of Geomorphology and Climatology due to the small number of researchers. Assuming that the rest of Physical Geographical studies with the exception of Geomorphological and Climatological studies are the Physical Geography in general, the studies of Physical Geogrpahy in general are summarized and several aspects are drown out as follows. First the descliption of all possible factors of natural environments was the pattern of early studies of Physical Geography and the tendency is maintained in the various kinds of research and project reports. Recently Physical Geographers have published several introductory textbooks or research monographs. In those books, however, the integrated approaches to Physical Geography were not suggested and the relationship between man and nature are dealt with in the elementary level. Second, the authentic soil studies of Physical Geographers are insignificant, because the studies of soil in Physical Geography have been mostly considered as the subsidiary means of Geomorphology Summarizing the studies of Soil Gegraphy by physical geographers and other Pedologists, the subjects are classified as soil-forming processes, soil erosions, soil in the tidal flat and reclaimed land, and soil pollution. Physical Geographers have focused upon the soil-forming processes in order to elucidate the geomorphic processes and the past climatic environment. The results of other subjects are trifling. Thirdy Byogeygrayhers and the results of studies are extremely of small number and the studies of Biogeography in Korea lines in the starting point. But, Biogeography could be a more unifying theme for the Physical-human Geography interface, and it would be expected to play an active part in the field of environmental conservation and resource management. Forth, the studies of Hydrogeography (Geographical Hydrology) in Korea have run through the studies of water balance and the morphometric studies such as the drainage network analysis and the relations of various kinds of morphometric elements in river. Recently, the hydrological model have introduced and developed to predict the flow of sediment, discharge, and ground water. The growth of groundwater studies is worthy of close attention. Finally, the studies on environmental problems was no mole than the general description about environmental destruction, resource development, environmental conservation, etc. until 1970s. The ecological perspectives on the relationship between man and nature were suggested in some studies of natural hazard. The new environmentalism having been introduced since 1980s. Human geographers have lead the studies of Environmental Perception. Environmental Ethics, Environmental Sociology, environmental policy. The Physical geographers have stay out of phase with the climate of the time and concentrate upon the publication of introductory textbooks. Recently, several studies on the human interference and modification of natural environments have been made an attempt in the fields of Geomorphology and climatology. Summarizing the studies of Physical Geography for 50 years in Korea, the integrated approaches inherent in Physical Geography disappeared little by little and the majol sub-divisions of Physical Ceography have develop in connection with the nearby earth sciences such as Geology, Meteorology, Pedology, Biology, Hydrology, etc been rediscovered by non-geographers under the guise of environmental science. It is expected that Physical Geography would revive as the dominant subject to cope with environmental problems, rearming with the innate integrated approaches.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.833-846
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• 2001

Recently, use of natural medicine is getting more attention, and some of them are believed to be effective in　the treatment of periodontitis. Among them, the seeds of safflower(Carthamus tinctrorius L.) have been proven to be effective through its use in bone diseases such as fracture and osteoporosis. During the last few years, studies using the seeds of safflower gown in Korea have been active, and it has been reported that safflower seed extract increase the proliferation and the alkaline phosphatase(ALP) activity of human periodontal ligament fibroblast(hPDLF), osteoblast, and that they promote the mineralization process. In animal studies, when safflower seed extract were administered orally new bone formation was promoted. Recently, in an effort to find out the most effective osteogenic components, among many components of the safflower seed, various safflower seed fraction extracts were obtained by multistep extraction of the safflower components using various solvents. Among these, saf-M-W fraction extracted by methanol and water was most effective in increasing osteogenic potential of osteoblasts. In this study, the effect of safflower seed fraction extract, saf-M-W, on the growth and differentiation of hPDLF and MC3T3-E1 cell was investigated. The toxicity of saf-M-W on both cells was measured using M'IT(3-(4,5dimethylthiazol-2-y1)-2,5-diphenyl tetrazolium bromide) test, and ALP activity was measured using the colorimetric assay of hPDLF. In addition, in MC3T3-El cells, the expression of ALP, bone sialoprotein(BSP) mRNA was observed using Northern blot, and the mineralized nodule formation Was observed using von Kossa stain and phase-contrast microscope. 1. In concentrations below $10{\mu}g/ml$, saf-M-W didn't show any toxicity on hPDLF and MC3T3-El cell. 2. The change in saf-M-W concentration had no effect on the ALP activity of hPDLF. 3. In MC3T-E1 cells, mRNA expressions of ALP and BSP were greater in the experimental group treated with $10{\mu}g/ml$ concentration of saf-M-W compared with the control group. 4. In MC3T3-El cells, abundance of mineralized nodules were formed in the experimental group treated with $10{\mu}g/ml$ Concentration of saf-M-W, while no mineralized nodule was formed in the control group. These results suggest that safflower seed fraction extract, saf-M-W. didn't show any toxicity on hPDLF and MC3T3-E1 cell at concentrations below $10{\mu}g/ml$ and effectively enhanced the differentiation and osteogenic potential of MC3T3-El cell.

• Radiation Oncology Journal
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• v.22 no.2
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• pp.145-154
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• 2004

Purpose : To examine whether a synthetic bile acid derivatives (HS-1200) sensitizes the radiation-induced apoptosis in human breast cancer cells (MCF-7) and to investigate the underlying mechanism. Materials and Methods : Human breast cancer cells (MCF-7) in exponential growth phase were treated with HS-1200 for 24 hours at 37$^{\circ}C$ with 5$\%$ CO$_{2}$ in air atmosphere. After removal of HS-1200, cells were irradiated with 2$\~$8 Gy X-ray, and then cultured Ii drug-free media for 24-96 hours. The effect of radiation on the clonogenicity of MCF-7 cells was determined with clonogenic cell survival assay with 16$\mu$M of HS-1200. The induction of apoptosis was determined using agarose gel electrophoresis and Hoechst staining. The expression level of apoptosis-related molecules, such as PARP, Bax, Bcl-2, Bak and AIF, were assayed by Western blotting analysis with 40$\mu$M of HS-1200 combined with 8 Gy irradiation. To examine the cellular location of cytochrome c, bax and AIF immunofluorescent stainings were undertaken. Results : Treatment of MCF-7 cells with 40$\mu$M of HS-1200 combined with 8 Gy irradiation showed several changes associated with enhanced apoptosis by agarose gel electrophoresis and Hoechst staining. HS-1200 combined with 8 Gy irradiation treatment also enhanced production of PARP cleavage products and increased Bax/Bcl-2 ratio by Western blotting. Loss of mitochondrial membrane potential ($\Delta$$\psi$$_{m}$) and increased cytochrome c staining indicated that cytochrome c had been released from the mitochondria in HS-1200 treated cells. Conclusion : We demonstrated that combination treatment with a synthetic chenodeoxycholic acid derivative HS-1200 and irradiation enhanced radiation-induced apoptosis of human breast cancer cells (MCF-7). We suggest that the increased Bax/Bcl-2 ratio In HS-1200 co-treatment group underlies the increased radio sensitivity of MCF-7 cells. Further futures studies are remained elusive.

• Journal of Life Science
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• v.19 no.11
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• pp.1581-1590
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• 2009

Hizikia fusiforme is a kind of brown edible seaweed that mainly grows in the temperate seaside areas of the northwest pacific, including Korea, Japan and China, and has been widely used as a health food for hundreds of years. Recently, H. fusiforme has been known to exert pharmacological activities including antioxidant, antimutagenic and anticoagulant activities. However, the molecular mechanisms of H. fusiforme in malignant cells have not been clearly elucidated yet. In this study, the effects of ethyl alcohol extract of H. fusiforme (EAHF) on the anti-proliferative effects of MDA-MB-231 and MCF-7 human breast cancer cells were investigated. EAHF treatment resulted in a concentration-dependent growth inhibition by including apoptosis in MDA-MB-231 cells and G1 phase arrest in MCF-7 cells, which could be proved by MTT assay, DAPI staining, agarose gel electrophoresis and flow cytometry analysis. In MDA-MB-231 cells, the increase in apoptosis induced by EAHF treatment correlated with up-regulation of pro-apoptotic Bax expression. EAHF treatment induced the proteolytic activation of caspase-3 and caspase-9, and a concomitant inhibition of poly (ADP-ribose) polymerase, $\beta$-catenin, phospholipase-${\gamma}1$ protein and DNA fragmentation factor 45/inhibitor of caspase-activated DNase. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of H. fusiforme.

• Journal of Life Science
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• v.23 no.3
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• pp.389-398
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• 2013

Platycodin D is a major constituent of triterpene saponins, which is found in the root of Platycodon grandiflorum, Platycodi Radix, which is widely used in traditional Oriental medicine for the treatment of many chronic inflammatory diseases. Several pharmacological effects of this compound have been reported recently, such as anti-inflammation, immunogenicity, anti-adipogenesis, lowered cholesterol, and anti-cancer activity. However, the mechanism by which this action occurs is poorly understood. In this study, we found that platycodin D greatly increased the potential of the anti-proliferative effect in various cancer cell lines. Our data revealed that platycodin D treatment resulted in a time- and concentration-response growth inhibition of U937 cells by inducing apoptosis, as evidenced by the formation of apoptotic bodies, chromatin condensation, and the accumulation of cells in the sub-G1 phase. Apoptosis induction of U937 cells by platycodin D correlated with an increase in the Bax/Bcl-2 ratio and caused the down-regulation of IAP family members. In addition, platycodin D treatment resulted in proteolytic activation of caspase-3, the concomitant degradation of poly(ADP-ribose) polymerases, and the collapse of the mitochondria membrane potential (${\Delta}{\Psi}_m$). However, the cytotoxic effects induced by platycodin D treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, which demonstrated the important role that caspase-3 played in the observed cytotoxic effect. These findings suggest that platycodin D may be a potential chemotherapeutic agent for use in the control of human leukemia U937 cells. These findings also provided important new insights into possible molecular mechanisms of the anti-cancer activity of platycodin D.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.776-784
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• 1998

Background: The cyclin D1 gene is one of the most frequently amplified chromosomal regions(11q13) in human carcinomas. In laryngeal and head and neck carcinomas, its overexpression has been shown to be associated with advanced local invasion and presence of lymph node metastases. Cyclin D1 may therefore playa key role in cell growth regulation and tumorigenesis. Lung cancer is a worldwide problem and in many contries it is the most lethal malignancy. As relapse is frequent after resection of early stage non-small cell lung cancer, there is an urgent need to define prognostic factors. Purpose: This study was undertaken to evaluate the prognostic value of the cyclin D1, that is one the G1 cyclins which control cell cycle progression by allowing G1 to S phase transition, on the patients in radically resected non-small cell lung cancer. Method: Total 81 cases of formalin-fixed paraffin-embedded blocks from resected primary non-small cell lung cancer from January 1, 1983 to July 31, 1995 at Hanyang University Hospital were available for both clinical follow-up and immunohistochemical staining using monoclonal antibodies for cyclin D1. Results : The histologic classification of the tumor was based on WHO criteria, and the specimens included 45 squamous cell carcinomas, 25 adenocarcinomas and 11 large cell carcinomas. Cyclin D1 overexpression was noted in 26 cases of 81 cases tested (30.9%). Cyclin D1 expression was not significantly associated with cell types of the tumor, pathological staging and the size of the tumor. But cyclin D1 overexpression was significantly correlated with positive lymph node metastasis(p=0.035). The mean survival duration was $22.76{\pm}3.50$ months in cyclin D1 positive group and $45.38{\pm}5.64$ months in eyclin D1 negative group. There was a nearly significant difference in overall survival between cyclin D1 positive and negative groups(p=0.0515) in radically resected non-small cell lung cancer. Conclusion: Based on this study, cyelin D1 overexpression appears an important poor prognostic indicator in non-small cell lung cancer and may have diagnostic and prognostic importance in the treatment of resectable non-small cell lung cancer.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.835-845
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• 1998

Background: Silica-induced lung diseases is characterized by the accumulation of inflammatory cells at early stage and fibrosis in pulmonary parenchyma and interstitium at late stage. As a consequence of inflammation, silicosis is accompanied with the expansion of interstitial collagen and the formation of fibrotic nodule. In this process, several kinds of lung cells produce cytokines which can amplify and modulate pulmonary fibrosis. The alveolar macrophage is a potent source of proflammatory cytokines and growth factor. But in the process of silicotic inflammation and fibrosis, there are many changes of the kinetics in cytokine network. And the sources of cytokines in each phase are not well known. Method: 2.5 mg of silica was instillated into the lung of C57BL/6J mice. After intratracheal instillation of silica, the lungs were removed for imunohistochemical stain at 1, 2, 7 day, 2, 4, 8, 12 week, respectively. We investigated the expression of IL-1$\beta$, IL-6, TNF-$\alpha$ and TGF-$\beta$ in lung tissue. Results: 1) The expression of IL-6 increased from 1 day after exposure to 8 weeks in vascular endothelium. Also peribronchial area were stained for IL-6 from 7 days and reached the peak level for 4 weeks. 2) The IL-1 $\beta$ was expressed weakly at the alveolar and peribronchial area through 12 weeks. 3) The TNF-$\alpha$ expressed strongly at alveolar and bronchial epithelia during early stage and maintained for 12 weeks. 4) TGF-$\beta$ was expressed strongly at bronchial epithelia and peribronchial area after 1 week and the strongest at 8 weeks. Conclusion: The results above suggests IL-6, TNF-$\alpha$ appear to be a early inflammatory response in silica induced lung fibrosis and TGF-$\beta$ play a major role in the maintenance and modulation of fibrosis in lung tissue. And the regulation of TNF-$\alpha$ production will be a key role in modultion of silica-induced fibrosis.

• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.242-248
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• 1979

To detect proper lytic assay conditions of the crude zumolyase from Arthrobacter luteus, effets of the various factors involved in the lytic system of Sacchromyces sake cultured with shaking in the malt extracts medium were investigated. The results are summarized as follows : 1. The susceptibilities of viable cells of S. sake from logarithmic growth phase to the lytic enzmye were much greater than those of the cells in lag and stationary phases. The cells cultured for 18 hr were the most susceptible to the enzyme. 2. Lytic activity of the enzyme toward the viable cells of S. sake was very low. It was, however, enhanced 4 folds of more by the pretreatment of the cells with 0.05 M sodium sulfite. 3. Lytic activity of the enzyme toward commercial baker's yeast cells was negligible, and the effect of sodium sulfite on the lysis of the cells also was nothing but a little. 4. The lyophilized cells of the baker's yeast showed more susceptibility to the lytic enzyme than viable cells of the yeast. No definite effect of sodium sulfite on the lysis of the lyophilized cells, however, was observed either baker's yeast of S. sake. 5. It appeared that the relationship between the reaction rate and the enzyme concentration on the lysis of the yeast cell walls followed enzyme kinetic theory, but one between the reaction rate and concentration of the yeast cells as substrates showed different pattern from that in enzyme kinetic theory. 6. After the preparation of crude zymolyase was kept at $7^[\circ}C$ for 10 days in the 0.05 M phosphate buffer, pH 7.5, the remainning lytic activity was about 80 %.