• Bulletin of the Society of Naval Architects of Korea
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• v.20 no.2
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• pp.1-20
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• 1983

In this paper design criteria for semi-submersibles, effective at the stage of basic design, are reviewed first generally. Thereafter an extensive study is focussed on essential problematic areas such as design load, heaving motion, overall structural analysis and welding technique. The necessity for this kind of research is apparent in the light of the fact that ocean exploration and exploitation becomes extended to deeper ocean and that semi-submersibles are the most favorite unit for operation under this environment. In some sense principles in naval architecture are indeed applicable to the design of semi-submersible. However, because of the difference in geometry between ships and semi-submersibles, there are significant deviations in design method. A thorough discussion is made on particular behaviours of a semi-submersible in stability, wave load, motion characteristics and structural responses. Then some calculation-procedures and design guidelines are tentatively proposed. A numerical calculation for a semi-submersible Sedco 708 is exemplified for better understanding of the concept. The structure has 4 main and another 4 secondary stabilizing columns with catamaran-type lower hull. In this example design condition is supposed to be 28m wave height, 90 knots wind speed for survival condition and seastate 6 for operational condition in water of 100m depth. The numerical result implies that the actual design of this model can be assessed close to optimum. Further intensive research is strongly required in the subject fields of dynamic stability, rational evaluation of wave load statistical basis for fatigue life judgement.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.180-186
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• 1998

A 10-week feeding experiment was conducted to determine the phosphorus requirement of juvenile Korean rockfish (Sebastes schlegeli). Three replicate groups of fish initially averaging 4.2g were fed the semipurified experimental diets containing graded levels of $NaH_2PO_4\;\cdot\;2H_2O$ to provide from $0.1\%$ to $1.32\%$ total phosphorus level in a flow-through seawater system. Korean rockfish muscle and casein were used as the protein sources of the basal diet. Weight gain, feed efficiency and protein retention of fish fed the $0.35\%$ phosphorus were higher than those of fish fed the $0.1\%$ phosphorus, although no significant improvements $(P>0.01)$ were observed above the level. Determined phosphorus requirement using the broken line model was found to be $0.3\%$ for weight gain. Moisture, protein and lipid contents of whole body and muscle were not affected by dietary phosphorus levels $(P>0.01)$. Lipid contents of liver in fish fed the $0.1\%$ phosphorus were lower than those in fish fed the $0.35\%$ and $1.32\%$ phosphorus $(P<0.01)$. Dietary phosphorus increased ash and phosphorus contents of the whole body, while those of bone were not affected $(P>0.01)$. The data obtained in this study indicate that a $0.3\%$ dietaryphosphorus level could be recommended for the optimum growth and efficient nutrient utilization of juvenile Korean rockfish.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.381-381
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• 2010

$(ZrO_2)_{0.66}(HfO_2)_{0.34}$ thin films as gate dielectrics have been proposed to overcome the problems of tunneling current and degradation mobility inachieving a thin equivalent oxide thickness. An extremely thin $SiO_2$ layer is used in order to separate the carrier in MOSFET channel from the dielectric field fluctuation caused by phonons in the dielectric which decreases the carrier mobility. The electronic and optical properties influenced the device performance to a great extent. $(ZrO_2)_{0.66}(HfO_2)_{0.34}$ dielectric films on p-Si (100) were grown by atomic layer deposition method, for which the conduction band offsets, valence band offsets and band gapswere obtained by using X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy. The band gap, valence and conduction band offset values for $(ZrO_2)_{0.66}(HfO_2)_{0.34}$ dielectric thin film, grown on Si substrate were about 5.34, 2.35 and 1.87 eV respectively. This band alignment was similar to that of $ZrO_2$. In addition, The dielectric function (k, $\omega$), index of refraction n and the extinction coefficient k for the $(ZrO_2)_{0.66}(HfO_2)_{0.34}$ thin films were obtained from a quantitative analysis of REELS data by comparison to detailed dielectric response model calculations using the QUEELS-$\varepsilon$(k, $\omega$)-REELS software package. These optical properties are similar with $ZrO_2$ dielectric thin films.

• Food Science of Animal Resources
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• v.43 no.4
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• pp.712-720
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• 2023

Osteoporosis is a growing global health concern primarily associated with decreased estrogen in postmenopausal women. Recently, some strains of probiotics were examined for potential anti-osteoporotic effects. This study intended to evaluate the impacts of Lactiplantibacillus plantarum MGE 3038 strain (MGE 3038) in ovariectomized rats. For this purpose, twelve weeks old female Wistar rats (n=21; 250-300 g) were divided into 3 groups; ovariectomy (OVX) group, OVX/MGE 3038 group and Sham group (control). In these groups; two went through respective OVX and one had daily MGE 3038 administration through oral gavage. Prior to 16 weeks after OVX, we collected blood samples and extracted the tibiae. We scanned the extracted tibiae by in-vivo micro-computed tomography (micro-CT) and evaluated pathology by hematoxylin and eosin (H&E) and Masson's trichrome staining. The serum levels of C-telopeptide of type I collagen (CTX), osteocalcin (OC), and the receptor activator of nuclear factor-κB ligand (RANKL) were examined. The OVX/MGE 3038 group showed increases in bone mineral density, trabecular bone volume, trabecular number, and trabecular thickness (Tb.Th), and a decrease in trabecular spacing than the OVX group. However, OVX/MGE 3038 group and control group were measurably comparable in Tb.Th. Micro-CT, H&E, and Masson's trichrome findings exhibited increased preservation and maintenance of trabecular bone structure in the OVX/MGE 3038 group in comparison to the OVX group. In serum, the levels of CTX, OC and RANKL were significantly different between the OVX and OVX/MGE 3038 groups. Taken together, L. plantarum MGE 3038 could be helpful for the treatment of osteoporosis.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.124-129
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• 2016

The extraction and purification of the anti-hyperglycemic α-glucosidase inhibitor from an edible mushroom, Pleurotus cornucopiae, were investigated. The inhibitor was maximally extracted when the P. cornucopiae fruiting body was treated with distilled water at 30℃ for 12 h. Purification was achieved using Sephadex G-100 and G-50 filtration chromatography, pepsin hydrolysis, and reverse-phase HPLC. The compound’s solid yield and inhibitory activity were 12.2% and 9.10 mg/ml of IC₅₀, respectively. The purified inhibitor contained two hexapeptides with Thr-Ile-Ala-Phe-Ile-Asp (A) and Tyr-Tyr-Ala-Ile-Gly-Asp (B) sequences and molecular weights of 678.79 Da (A) and 643.7 Da (B). The purified inhibitor showed a mixed inhibition pattern to α-glucosidase and a dose-dependent anti-hyperglycemic effect in a streptozotocininduced diabetic Sprague-Dawley rat model, exhibited by decreased blood glucose levels at doses of 50 and 300 mg/kg.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.29 no.1
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• pp.16-32
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• 2016

Objective : The water extract of Bojungikgi-tang (BTE) composed with Ginseng Radix, Astragali Radix, Angelicae gigantis Radix, Atractylodes Rhizoma alba, Aurantii nobilis Pericarpium, Glycyrrhizae Radix, Cimicifuga Rhizoma, and Bupleuri Radix and it has been traditionally used for chronic diseases or weakness after illness in oriental countries. However, little is known about the effects of aqueous extract of BTE on trimellitic anhydride (TMA)-induced contact hypersensitivity (CHS). Therefore, the aim of this study was to investigate the effects of BTE on TMA-induced CHS in BALB/c mice.Methods : In this study, the extract of BTE was prepared by extracting with distilled water at 100℃ for 2.5 h. The extract was freeze-dried following filtration through 0.45 μm filter. Mice were orally administrated with or without BTE extract of different doses (25-200 ㎎/㎏/day) for 28 days. During the challenge period, mice were externally applied with different doses of BTE extract one time per day 30 min before TMA treatment. I examined the effects of BTE on the serum levels of IgE, IgG1, IgG2a, and IgG2b, nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in isolated peritoneal macrophages, Th2 cytokine production in isolated spleen cells, ear swelling responses, and the leukocyte infiltration induced by TMA.Results : The orally and externally administration of BTE dose-dependently reduced the serum levels of hapten-specific immunoglobulin E (IgE), IgG1 titer, and PGE₂ production as well as ear swelling responses and leukocyte infiltration in TMA-induced BALB/c mice. The levels of NO and PGE₂ production from peritoneal macrophages stimulated with TMA-BSA were markedly suppressed by pretreatment with BTE in a concentration dependent manner. Furthermore, the levels of Th2 cytokines (IL-4, IL-5, IL-13) production from spleen cells stimulated with ConA were markedly suppressed by BTE treatment in a concentration dependent manner.Conclusions : These results suggest that BTE treatment suppresses chronic contact hypersensitivity, and it can be assumed that the suppression of ear swelling, serum IgE, NO and PGE₂ levels, leukocyte infiltration, and Th2 cytokines in an animal model. Therefore, these properties may contribute to the strong anti-CHS response effect of BTE.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.204-210
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• 2002

The quality characteristics and sensory evaluation of chungkookjang were investigated. The samples were prepared and fermented by the inoculation of Bacillus strains; B. subtilis, B. natto and B. licheniformis as a single starter, and mixed culture of B. natto and B. licheniformis on the industrialized model system. It was shown that microbial growth, protease activity, contents of amino-and ammonia-nitrogen and contents of organic acid were higher in B. subtilis inoculated sample, and were lower in B. licheniformis inoculated one. General quality characteristics of sample inoculated by mixed culture of B. natto and B. licheniformis took a middle position between each B. natto and B. licheniformis inoculated one. Fifty eight species of odor components were identified. Ethanol, 3-methyl-1-butanol, acetic acid, benzaldehyde and alkyl pyrazines were identified in all samples and most of other flavor components were strain specific. The contents of unpleasant smell components, alkyl pyrazines and benzaldehyde, were lower in B. licheniformis inoculated sample. The sensory evaluations showed that chungkookjang manufactured from mixed culture of B. natto and B.licheniformis was most acceptable. Therefore, results indicated that chungkookjang manufactured from mixed culture of B. natto and B. licheniformis induced better sensory quality than that of the control.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.585-590
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• 2003

Activity-guided fractionation of the EtOAc-soluble extract of the whole plants of Sida acuta using a bioassay based on the induction of quinone reductase (OR) in cultured Hepa 1c1c7 mouse hepatoma cells, led to the isolation of ten active compounds of previously known structure, quindolinone (1), cryptolepinone (2), 11-methoxyquindoline (3), N-trans-feruloyltyramine (4), vomifoliol (5), loliolide (6), 4-ketopinoresinol (7), scopoletin (8), evofolin-A (9), and evofolin-B (10), along with five inactive compounds of known structure, ferulic acid, sinapic acid, syringic acid, ($\pm$)-syringaresinol, and vanillic acid. These isolates were identified by physical and spectral data measurement. A new derivative of quindolinone, 5,10-dimethylquindolin-11-one (1a) was synthesized and characterized spectroscopically. Of the active substances, compounds 1-3 and 1a exhibited the most potent QR activity, with observed CD (concentration required to double induction) values ranging from 0.01 to 0.12 $\mu$ g/mL. Six compounds were then evaluated in a mouse mammary organ culture assay, with cryptolepinone (2), N-trans-feruloyltyramine (4), and 5,10-dimethylquindolin-11-one (1a) found to exhibit 83.3, 75.0, and 66.7% inhibition of 7,12-dimethylbenz[a]anthracene-induced preneoplastic lesions, respectively, at a dose of 10 $\mu\textrm{g}$/mL.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.349-360
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• 2020

Bio-conversion manufacturing technology has been developed to produce ginsenoside Rd which is increasingly in demand as a cosmetic material due to various possibilities related to improving skin function. In order to convert ginsenoside Rb1 which is contained in red ginseng saponin (RGS) into Rd, several commercial enzymes were tested. Viscoflow MG was found to be the most efficient. In order to optimize the conversion of RGS to ginsenoside Rd by enzymatic transition was carried out using response surface methodology (RSM) based on Box-Behnken design (BBD). The main independent variables were RGS concentration, enzyme concentration, and reaction time. Conversion of ginsenoside Rd was performed under 17 conditions selected according to BBD model and optimization conditions were analyzed. The concentration of the converted ginsenoside Rd ranged from 0.3113 g/L to 0.5277 g/L, and the highest production volume was obtained under condition of reacting 2% RGS and 1.25% enzyme for 13.5 hours. Consequently, RGS concentration, enzyme concentration which is 0.05 less than p-value and among the interactions between the independent variables, the interaction between enzyme concentration and reaction time was confirmed to be the most influential.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.707-711
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• 2008

The principal objective of the current study was to isolate a purpurogallin derivative as an oxidation product from gallic acid, in an effort to assess the anti-inflammatory effects of this compound. Purpurogallin derivative is known to be the one of the oxidation products of gallic acid. This compound has been identified as a minor chemical component in fermented tea products. It has been previously demonstrated that theaflavins, the oxidation products of catechins found in fermented tea products, exert profound antioxidant and anti-inflammatory effects. However, the biological activities of a minor chemical component in fermented teas have yet to be evaluated. Purpurogallin carboxylic acid (PCA) was identified as a major oxidation product of gallic acid from a peroxidase/hydrogen peroxide oxidation model system. The identity of the PCA was verified by $^{1}H$ NMR, $^{13}C$ NMR and MS techniques. PCA treatment significantly suppressed the generation of pro-inflammatory mediators including nitric oxide and IL-6 in lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophages. According to the nitrite assay, PCA 100, 75, and $50{\mu}g/mL$ treatment dose-dependently inhibited NO production by 57.6, 41.5, and 21.8%, respectively, in LPS-stimulated RAW264.7 murine macrophage cells. Moreover, IL-6 production was inhibited to a significant degree with PCA treatment of 100 and $75{\mu}g/mL$ at 43.1 and 23.9%, respectively. PCA treatment also significantly suppressed $PGE_2$ production at levels of 100 and $75{\mu}g/mL$. These results showed that PCA exerts inhibitory effects on the production of inflammatory mediators.