• Korean Journal of Food Science and Technology
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• 제40권5호
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• pp.522-527
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• 2008

Low molecular peptides were isolated from Asterias amurensis via SDS-PAGE. The peptides were separated via consecutive gel filtration as five fractions (F1-F5) according to molecular weights, based on the results of MALDI-TOF MS analysis. The molecular weight of the most active peptide was estimated as 15,000 daltons. The peptide showed cytotoxicity on normal human fibroblast cells at levels as low as 20% when 1.0 mg/mL of the samples was added. The peptide also exhibited higher levels of nitric oxide production from macrophages than the lipopolysaccaharides. It was determined that prostaglendin $E_2$ production was significantly inhibited, up to 127.8% as compared to the control. The low molecular peptide inhibited hyaluronidase activity as 535.7 ${\mu}g/mL$ of $IC_{50}$. It can be concluded that the relatively low molecular weight peptide, fucoidan, from A. amurensis has excellent cosmetic and immunomodulatory activities, which can be considered as a possible resource of new cosmetic agents for skin immunomodulation.

• Korean Journal of Food Science and Technology
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• 제42권1호
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• pp.90-96
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• 2010

In this study, the anti-oxidant, anti-tumorigenic, anti-hypertensive, anti-thrombic, anti-diabetic, and anti-inflammatory properties of 18 different species of genus Pleurotus were investigated. In addition, the amino acid, $\beta$-glucan, and polyphenol content were also measured. All species contained more than 20 mg% of polyphenol with the highest contents found in Pleurotus cornucopiae var. citrinopileatus (yellow pleurotus) ($39.13{\pm}0.82\;mg%$). The $\beta$-glucan contents was also the highest in yellow Pleurotus ($37.67{\pm}0.22%$) followed by Won-Hyeong1 (C, $28.75{\pm}0.61%$) and Jang-an PK (A, $27.95{\pm}0.33%$). The yellow Pleurotus exhibited the highest antioxidant activity as assessed by the DPPH scavenging rate with an $IC_{50}$ value of $2.94{\pm}0.44\;mg/mL$. Ethanol extracts from the yellow Pleurotus treated at 1% concentration showed cytotoxic activity up to 36.9% in the human embryonic kidney 293T cell lines. The yellow Pleurotus also showed the highest inhibitory effects on ACE activity ($60.52{\pm}0.2%$). Finally, the yellow Pleurotus exhibited anti-diabetic and anti-inflammatory properties as shown by inhibition of $\alpha$-amyloglucosidase activity ($50.5{\pm}0.8%$) and nitric oxide production ($68.4{\pm}0.3%$). Taken together, our data indicate the yellow pleurotus is a promising functional food ingredients.

• Korean Journal of Food Science and Technology
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• 제46권6호
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• pp.729-733
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• 2014

Laminaria japonica roots have not been used practically in Korea. In this study, in order to promote the use of these by-products, the anti-inflammatory activity of an ethanol extract of Laminaria japonica root (LJREE) was investigated using a lipopolysaccharide (LPS) to induce an inflammatory response in RAW 264.7 cells. To examine the potential anti-inflammatory effects of LJREE, levels of nitric oxide (NO) and pro-inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and interleukin-$1{\beta}$ (IL-$1{\beta}$), and cell proliferation were measured. We found that NO levels decreased in a dose-dependent manner, the production of IL-6, TNF-${\alpha}$, and IL-$1{\beta}$ was suppressed, and the production of IL-$1{\beta}$ was inhibited over 30% after treatment with $100{\mu}g/mL$ LJREE. In conclusion, the proliferation of RAW 264.7 cells, measured by MTT assay, confirmed that LJREE may have significant effects on inflammatory factors without any cytotoxicity, making it a potential anti-inflammatory agent.

• Restorative Dentistry and Endodontics
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• 제23권2호
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• pp.537-549
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• 1998

The purpose of this study was to evaluate the influence of root resection and retrograde cavity preparation methods on the apical leakage in endodontic surgery. To investigate the effect of various root resection and retrograde cavity preparation methods on the apical leakage, 71 roots of extracted human maxillary anterior teeth and 44 mesiobuccal roots of extracted human maxillary first molars were used. Root canals of the all the specimens were prepared with step-back technique and filled with gutta-percha by lateral condensation method. Three millimeters of each root was resected at a 45 degree angle or perpendicular to the long axis of the tooth according to the groups. Retrograde cavities were prepared with ultrasonic instruments or a slow-speed round bur, and occlusal access cavities were filled with zinc oxide eugenol cement. Three coats of clear nail polish were placed on the lateral and coronal surfaces of the specimens except the apical cut one millimeter. All the specimens were immerged in 2% methylene blue solution for 7 days in an incubator at $37^{\circ}C$. The teeth were dissolved in 14 ml of 35% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data were analysed statistically using two-way ANOVA and Duncans Multiple Range Test. The results were as follows: 1. No statistically significant difference was observed between ultrasonic retrograde cavity preparation method and slow-speed round bur technique, without apical bevel (p>0.05). 2. Ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, with bevel (p<0.0001). 3. No statistically significant difference was found between beveled resected root surface and non-beveled resected root surface, with ultrasonic technique (p>0.05). 4. Non-beveled resected root surface showed significantly less apical leakage than beveled resected root surface, with slow-speed round bur technique (p<0.0001). 5. No statistically significant difference in apical leakage was found between the group of retrograde cavity prepared parallel to the long axis of the tooth and the group of one prepared perpendicular to the long axis of the tooth (p>0.05). 6. Regarding isthmus preparation, ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, in the mesiobuccal root of maxillary molar, without bevel (p<0.0001).

• Restorative Dentistry and Endodontics
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• 제36권5호
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• pp.419-424
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• 2011

Objectives: This study was aimed to determine the effects of temporary sealing materials on microtensile bond strength between resin-coated dentin and resin inlay and to compare the bonding effectiveness of delayed dentin sealing and that of immediate dentin sealing. Materials and Methods: The teeth were divided into 4 groups: group 1, specimens were prepared using delayed dentin sealing after temporary sealing with zinc oxide eugenol (ZOE); group 2, specimens were prepared using immediate dentin sealing and ZOE sealing; group 3, specimens were prepared using immediate dentin sealing and Dycal (Dentsply) sealing; group 4, specimens were prepared using immediately sealed, and then temporarily sealed with a resin-based temporary sealing material. After removing the temporary sealing material, we applied resin adhesive and light-cured. Then the resin inlays were applied and bonded to the cavity with a resin-based cement. The microtensile bond strength of the sectioned specimens were measured with a micro-tensile tester (Bisco Inc.). Significance between the specimen groups were tested by means of one-way ANOVA and multiple Duncan's test. Results: Group 1 showed the lowest bond strength, and group 4 showed the highest bond strength (p < 0.01). When temporary sealing was performed with ZOE, immediate dentin sealing showed a higher bonding strength than delayed dentin sealing (p < 0.01). Conclusions: Based on these results, immediate dentin sealing is more recommended than delayed dentin sealing in bonding a resin inlay to dentin. Also, resin-based temporary sealing materials have shown the best result.

• Economic and Environmental Geology
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• 제34권6호
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• pp.627-648
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• 2001

At least two distinct types of layering are present in the middle zone of the Skaergaard intrusion; alternating plagioclase-rich and pyroxene-rich, macro-rhythmic layers, and smaller scale, modally-graded, rhythmic layers. The macro-rhythmic layers are ubiquitous in the middle zone of the Layered Series, but are not observed in the lower and upper zone of the Layered Series or in the wall or roof tories of the intrusion. They range from 0.3 to 17.3 m in thickness, have sharp upper and lower boundaries, and can be traced laterally for over 2 ]fm in outcrop. Although individual macrorhythmic layers are not internally graded, many contain smaller-scale, modally-graded layers. Modally-graded. rhythmic layers are a common feature of the Layered Series but are not abundant in either the Upper Border Series or the Marginal Border Series. They range in thickness from 1 to 50 cm and can be traced laterally in outcrop for up to 100 m. Their lateral termination ranges from abrupt to gradational, and they are often associated with cut and fill structures and crossbedding suggestive of current activity. They are characterized by sharp lower and gradational upper contacts, and by strong intra-layer modal grading with olivine, ilmenite, and magnetite concentrated at the base, pyroxene concentrated above the base, and plagioclase concentrated at the top. The layers are also grain-size graded with the maximum size for each phase occurring at the horizon in the layer where the phase is most abundant. Modally-graded, rhythmic layers in the middle zone of the Layered Series occur within both plagioclase-rich and pyroxene-rich macro-rhythmic layers.

• Applied Chemistry for Engineering
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• 제17권5호
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• pp.483-489
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• 2006

The behavior of rare earth compounds such as $La_{2}O_{3}$, $CeO_{2}$, and $Ca(OH)_{2}$ on the removal of fluoride and heavy metals in the steel wastewater has been investigated. The removal mechanism of fluoride by rare earth elements has been known to be the formation of insoluble compounds between $F^{-}$ and cations such as $La^{3+}$ and $Ce^{4+}$ produced by the dissociation of rare earth compounds (To reduce the running cost of the fluoride wastewater treatment facility, their fluoride removal efficiencies were compared with those of inexpensive rare earth minerals such as natural lanthanide and cerium compound used as a glass polishing agent). All of the rare earth oxides used in this study showed a higher removal efficiency of fluoride than $Ca(OH)_{2}$ in the wastewater. In the case of artificial HF solution, the removal efficiency of fluoride showed in the order: $CeO_{2}$-mineral < $CeO_{2}$ < $Ca(OH)_{2}$ < $La_{2}O_{3}$-mineral < $La_{2}O_{3}$. However, the removal efficiency of fluoride in the wastewater increased in the following order: $Ca(OH)_{2}$ < $CeO_{2}$ mineral < $CeO_{2}$ < $La_{2}O_{3}$ mineral < $La_{2}O_{3}$. All agents showed high efficiencies for the removal of Mn and total Cr in the rare earth compounds. In the case of $Ca(OH)_{2}$, fluoride removal decreased with increasing pH while. However, the rare earth compounds showed a higher fluoride removal in higher pH condition, the optimum pH condition seemed to be around 7 considering both water quality and fluoride removal. Under the pH 7 condition, the $Ca(OH)_{2}$ was superior to rare earth compounds in Mn removal and the lanthanide was superior to others in total Cr removal.

• Applied Chemistry for Engineering
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• 제7권6호
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• pp.1078-1086
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• 1996

The peroxo-polytungstic acid was formed by the direct reaction of tungsten powder with the hydrogen peroxide solution. Peroxo-polytungstic powder were prepared by rotary evaporator using the fabricated on to ITO coated glass as substrate by dip-coating method using $2g/10mL(W-IPA/H_2O)$ sol solution. A substrate was dipped into the sol solution and after a meniscus had settled, the substrate was withdrawn at a constant rate of the 3mm/sec. Thicker layer could be built up by repeated dipping/post-treatment 15 times cycles. The layers dried at the temperature of $65{\sim}70^{\circ}C$ during the withdrawn process, and then tungsten oxides thin film was formed by final heating treatment at the temperature of $230{\sim}240^{\circ}C$ for 30min. A linear rotation between the thickness of thin film and the number of dipping/post-treatment cycles for tungsten oxides thin films made by dip-coating was found. The thickness of thin film had $60{\AA}$ after one dipping. From the patterns of XRD, the structure of tungsten oxides thin film identified as amorphous one and from the photographs of SEM, the defects and the moderate cracks were observed on the tungsten oxides thin film, but the homogeneous surface of thin films were mostly appeared. The electrochemical characteristic of the $ITO/WO_3$ thin film electrode were confirmed by the cyclic voltammetry and the cathodic Tafel polaization method. The coloring bleaching processes were clearly repeated up to several hundreds cycles by multiple cyclic voltammetry, but the dissolved phenomenon of thin film revealed in $H_2SO_4$ solution was observed due to the decrease of the current densities. The diffusion coefficient was calculated from irreversible Randles-Sevick equation from the data obtained by the cyclic voltammetry with various scan rates.

• Journal of Food Hygiene and Safety
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• 제33권5호
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• pp.361-368
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• 2018

N-nitrosamines are probable or possible human carcinogens, which are produced by the reaction between secondary amines and nitrogen oxide in the acidic environment or by heating. Common risk assessment procedure involves the comparison between exposures expressed in the unit, mg/kg body weight/day and the Health-Based Reference dose expressed in the same unit. This procedure is suitable for the policy decision-making and is considered as inappropriate for the consumers to get information about their dietary decision-making. Therefore, the distributions of NDMA (N-nitrosodimethylamine), NDBA (N-nitrosodibutylamine), the six N-nitrosamines (NDMA, NDBA, NDEA (N-nitrosodiethylamine), NPYR (N-nitrosopyrrolidine), NPIP (N-nitrosopiperidine), and NMOR (N-nitrosomorpholine) in the menus grouped based on the presence of main ingredients and cooking methods were analyzed to generate consumer-friendly information regarding food contaminants. Recipes and intakes were taken from 2014 to 2016 KNHANES (The Korean National Health and Nutrition Examination Survey) and only the data from ages of 7 years or older were used. The contamination data were collected from the 2014~2016 Total Diet Study and all the analysis were performed using R software. Rockfish, eel, anchovy broth and pollock were mainly exposed to N-nitrosamines. In terms of cooking methods, soups and stews appeared to contain the highest amount of N-nitrosamines. Cereals, fruits, and dairy products in the ingredient categories, and rice dishes and rice combined with others in recipe categories had the lowest level exposure to N-nitrosamines. In case of N-nitrosamines, unlike other cooking related food contaminants, boiled dishes such as soups and stews and dishes mainly consisting of fishes and shellfishes had highest level of exposure, showing a large discrepancy with the previous thought of processed meat is the main source of N-nitrosamines.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제20권1호
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• pp.49-59
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• 1984

Optimizing investigation of characteristics of underwater welding by a gravity type arc welding process was experimentally carried out by using six types of domestic coated welding electrodes for welding of domestic marine structural steel plates (KR Grade A-1, SWS41A, SWS41B,) in order to develop the underwater welding techniques in practical use. Main results obtained are summarized as follows: 1. The absorption speed of the coating of domestic coated lime titania type welding-electrode became constant at about 60 minutes in water and it was about 0.18%/min during initial 8 minutes of absorption time. 2. Thus, the immediate welding electrode could be used in underwater welding for such a short time in comparison with the joint strength of in-atmosphere-and on-water-welding by dry-, wet-or immediate-welding-electrode. 3. By bead appearance and X-ray inspection, ilmenite, limetitania and high titanium oxide types of electrodes were found better for underwater-welding of 10 mm KR Grade A-1 steel plates, while proper welding angle, current and electrode diameter were 6$0^{\circ}C$, above 160A and 4mm respectively under 28cm/min of welding speed. 4. The weld metal tensile strength or proof stress of underwater-welded-joints has a quadratic relationship with the heat input, and the optimal heat input zone is about 13 to 15KJ/cm for 10mm SWS41A steel plates, resulting from consideration upon both joint efficiency of above-100% and recovery of impact strength and strain. Meanwhile, the optimal heat input zone resulting from tension-tension fatigue limit above the base metal's of SWS41A plates is 16 to 19KJ/cm. Reliability of all the empirical equations reveals 95% confidence level. 6. The microstructure of the underwater welds of SES41A welded in such a zone has no weld defects such as hydrogen brittleness with supreme high hardness, since the HAZ-bond boundary area adjacent to both surface and base metal has only Hv400 max with the microstructure of fine martensite, bainite, pearlite and small amount of ferrite.