• Korean Journal of Environmental Biology
• /
• v.32 no.4
• /
• pp.344-352
• /
• 2014

The aim of the present study was to assess the effects of ammonia on physiological responses in Korean rockfish (Sebastes schlegeli). Interestingly, no mortality were observed when the specimens ($301.1{\pm}8.0g$) were exposed to five levels of un-ionized ammonia ($NH_3$) (control, 1, 2, 4, $8mg\;L^{-1}$) for 3 hours. Furthermore, a significantly higher increase in gill $Na^+/K^+$-ATPase (NKA) pump activity with was detected due to the ammonia exposure. The activity of the fishes were found to be 4 and $8mg\;L^{-1}$ $NH_3$, which was significantly high compared to normal $1mg\;L^{-1}$ $NH_3$. Although ammonia exposure had no effect on plasma $Cl^-$, exposure to both 4 and $8mg\;L^{-1}$ $NH_3$, however it led to increase in the plasma $Na^+$, $K^+$ and osmolality levels. Also, prolong ammonia exposure cause increase of plasma cortisol and glucose levels. The increase in glucose was accompanied by an increase in cortisol. The fish exposed to 4 and $8mg\;L^{-1}$ $NH_3$ showed significantly higher hematocrit than control group than those exposed to 1 and $2mg\;L^{-1}$ $NH_3$. The intensity of cell damage increased with the increase concentration and exposure to ammonia. Furthermore, hyperplasia, separation and epithelial necrosis were also observed in gill tissues. Taken together, the results showed that direction of changes to the investigated parameters can be used to determine the physiological responses of Korean rockfish to ammonia.

• Ecology and Resilient Infrastructure
• /
• v.2 no.1
• /
• pp.22-32
• /
• 2015

This study investigated the difference in fish community structures in a main channel and an isolated former channel, considering the environmental factors in the Mangyeong River, Korea. Principal component analysis (PCA) with environmental factors showed that former channels were composed of a fine substrate covered by in-stream vegetation, whereas the main channel was covered by a wide range of substrates with a higher dissolved oxygen and conductivity. The result of the hierarchical cluster analysis with species abundance delineated to the four main groups; three abandoned channel groups and one main channel group. Non-metric multidimensional scaling (NMDS) showed that fish community structures of each study site differed from environmental factors: former channel fish communities were positively related to in-stream vegetation cover, whereas main channel fish communities were positively associated with dissolved oxygen and conductivity. The results indicated that channelization, where there was a separation between the former channel and the main channel, had detrimental effects on fish community structures of both the main channel and the abandoned channel in the Mangyeong River. In conclusion, this study suggested that the connectivity between the main channel and abandoned channel were required to enhance both habitat structural diversity and species diversity of the Mangyeong River.

• Research in Community and Public Health Nursing
• /
• v.17 no.4
• /
• pp.512-520
• /
• 2006

Purpose: To investigate the risk factors of arthritis, this study was carried out with 1,829 Korean women aged between 40-64 who responded to a health behavior survey. Methods: Data were extracted from the results of the 2001 National Survey on Health and Nutrition conducted by the Ministry of Health and Welfare. Results: 1 Financial difficulty and continuous anxiety about health were directly associated with arthritis. The odd ratios of these two factors of arthritis were 1.43 and 1.82 respectively. 2. With regard to the presence or absence of arthritis according to demographic characteristic, the incidence of arthritis was higher in the age between 50-64, in the group whose education level was middle school or lower, and in those who experienced the death of spouse, divorce or separation. Nevertheless, it was not significantly different according to financial status and employment status. 3. Concerning the presence or absence of arthritis according to psychological characteristic, the incidence of arthritis was found to be higher in those who were not healthy by subjective health assessment, in those who were always anxious about their health, in those who were always depressed and sad, and in those who felt heavy stress. 4. With regard to the presence or absence of arthritis according to the health behavior, the incidence of arthritis was higher in postmenopausal cases and cases who were having hormone therapy, and the incidence of arthritis was higher in those who did not drink alcohol, those with BMI higher than 25, and those who slept shorter than 7 hours a day. Conclusion: Based on the above results, it is required to provide a means applicable to communities by developing preventive education that can prevent the incidence of arthritis in middle-aged women as well as intervention programs.

• Journal of the East Asian Society of Dietary Life
• /
• v.18 no.1
• /
• pp.87-94
• /
• 2008

In this study, a nanatural fermentation starter formulation was developed for manufacturing bread products by substituting baker's yeast with naturally fermented raisin extract and sourdough. Four experimental groups containing 2.5, 5.0, 7.5, 10% naturally fermented raisin extract per 2,000 g of flour were compared based on quality characteristics, including the fermentation power on dough expansion, specific volume, baking loss, water activity, color, textural characteristics, and internal surface appearance. The activities of the naturally fermented raisin extract were examined in terms of pH changes, total titratable acidity, brix, and viable yeast counts. The raisin extract, which was cultured for 7 days at 30$^{\circ}C$, smelled of alcohol and produced $CO_2$. Yeast were also found in the extract after separation. As the incubation time of the raisin extract and sourdough increased, pH decreased, while total titratable acidity increased. The brix of the raisin extract increased until the $2^{nd}$ day of fermentation, and viable yeast counts increased until the $5^{th}$ day however, these gradually decreased by the $7^{th}$ day. The fermenting power on dough expansion increased in the bread with increasing incubation time. The bread samples containing 7.5% and 10% raisin extract had significantly higher specific volumes than the other samples. Baking loss was minimal with the 2.5% extract substitution. In analyzing the crumb, water activity, redness, and yellowness were highest in the 10.0% raisin extract bread samples, and lightness was maximal in the 5.0% group. In terms of textural characteristics, hardness was lowest with the 2.5% extract substitution. Gumminess, springiness, and chewiness were not significantly different among the bread samples. Cohesiveness was highest at the 7.5% extract substitution level, and resilience was lowest at the 10% level. In conclusion, based on the results, a natural fermentation starter formulated with 2.5% naturally fermented raisin extract (1 part raisins and 1.5 parts water) and 70% sourdough (1 part rye flour and 1 part water) has high potential as a baker's yeast substitute for making naturally fermented bread.

• Journal of Conservation Science
• /
• v.26 no.4
• /
• pp.445-458
• /
• 2010

The deterioration and structural damage such as exfoliation, cracks, and separation of painted layer on the wall paintings of Maitreya Hall in Geumsan-sa temple have been accelerated since it was re-positioned to the original place after the dismantling from the building in 1993. The examination of which result and analysis described in this study, is a preliminary survey for establishing conservation plan of the wall paintings. It aimed at the understanding of the physical and chemical characteristics of the materials applied in the 1993 conservation. The research focused on the south walls which displayed the worst condition compared to other walls. Samples for the examination for the understanding of micro-structure, chemical composition, cristalisation, and particle distribution, were collected for finishing, middle, and consolidated layers of the walls between pillars and the ones between brackets. Those samples were collected from separated fragments of the walls. The sample analysis displayed that: 1. the 1993 conservation used the similar type of weathered soil as the original for the finishing layer, and such soil and sand for the middle layer; 2. those walls are composed of a group of mineral particles which are relatively equal in size and shape and in their distribution; 3. the mineral particles were cohered forming solid aggregate due to the application of acrylic resin for the reinforcement on the wall. The main composition of crystalisation on the first and the second reinforcement layers of the back walls were lime plaster ($CaSO_4{\cdot}2H_2O$). The overall examination confirmed that the priority of the future conservation treatment should be given to the removal of the first and the second layers of reinforcement and the treatment on the back walls which were partially consolidated.

• Advances in Traditional Medicine
• /
• v.4 no.2
• /
• pp.104-111
• /
• 2004

Sasang Constitutional Medicine is a major branch of Korean Traditional Oriental Medicine. The differences of disease susceptibility to be shown in Sasang constitution may be due to genetic factors. Therefore, we examined interrelationship among cerebral infarction (CI), apolipoprotein E (apoE) gene polymorphism, and Sasang constitutional classification. ApoE is a key protein modulating the highly atherogenic apoB containing lipoproteins and is a candidate gene for the development of coronary artery disease (CAD). The ${\varepsilon}2\;and/or\;{\varepsilon}4$ alleles were the first to be implicated in premature CAD, which resulted in this polymorphism being extensively studied. We investigated the association between apoE genotype and CI by case-control study in a Korean population. We also classified CI patients and control group into groups according to Sasang Constitutional Medicine. 196 CI patients and 379 controls without CI were examined. ApoE genotype was determined by 8% polyacrylamide gel separation after DNA amplification. A significant difference in the apoE genotype distribution was observed in the CI patients compared with that in controls ($X^{2}$=14.920, df=4, P=0.005). Also, the frequency of Taeumin constitution in patients with CI was significantly higher than that in controls (58.0% vs. 36.9%; P<0.001). However, the Taeumin constitution did not enhance the relative risk for CI in the subjects with apoE ${\varepsilon}2\;and/or\;{\varepsilon}4$ alleles. No differences in the apoE genotypes frequencies were observed in the Taeumin compared with that in the other constitutions. In addition, we investigated whether the DD genotype of angiotensin converting enzyme (ACE) gene, a candidate gene for CI, was associated with CI, Taeumin constitution, and apoE polymorphism. As a result, the frequency of Taeumin constitution was significantly higher in CI patients with both apoE ${\varepsilon}3/{\varepsilon}4$ and ACE ID/DD genotypes than in the remaining Sasang constitutions (14.5% vs. 8.3% and 0%) ($X^{2}$=13.521, df=6, P=0.035). In summary, we concluded that the apoE polymorphism is a major risk factor for CI in Koreans and the ACE ID/DD genotype enhanced the relative risk for CI in the subjects with apoE ${\varepsilon}3/{\varepsilon}4$ genotype and Taeumin constitution.

• Restorative Dentistry and Endodontics
• /
• v.12 no.2
• /
• pp.45-53
• /
• 1987

The purpose of this study was to evaluate the tensile bond strength between composite resin and the human enamel. Three composite resin systems, two chemical (Clearfil Posterior, and Clearfil Posterior-3) and one light cure (Photo Clearfil-A), used with and without an intermediate resin (clearfil bonding agent), were evaluated under different amounts of load (10g, 200g and 200g for a moment) for in vitro tensile bond strength to acid-eched human enamel. Clinically intact buccal or lingual surfaces of 144 freshly extracted human permanent molars, embedded in acrylic were flattened with No #600 carborundum discs. Samples were randomly assigned to the different materials and treatments using a table of random numbers. Eight samples were thus prepared for each group(Table 2) these surfaces were etched with an acid etchant (Kurarey Co. Japan) in a mode of etching for 30 seconds, washing for 15 seconds, and drying for 30-seconds. During the polymerization of composite resin on the acid-etched enamel surfaces with and without bonding agent 10-gram, 200 gram and temporary 200 gram of load were applied. The specimens were stored in 50% relation humidity at $37^{\circ}C$ for 24 hours before testing. An universal Testing machine (Intesco model No. 2010, Tokyo, Japan) was used to apply tensile loads in the vertical directed (fig 5), and the force required for separation was recorded with a cross head speed of 0.25 mm/min and 20 kg in full scale. The results were as follow: 1. The tensile bond strength was much greater in applying a bonding agent than in not doing that. 2. The tensile bond strength of chemical cure composite resin was higher than that of light cure composite resin with applying on bonding agent on the acid-etched enamel. 3. In case of not applying a bonding agents on the acid-etching enamel, the highest tensile bond strength under 200 gram of load was measured in light cure composite resin. 4. The tensile bond strength under 200-gram of load has no relation with applying the bonding agent. 5. Under the load of 10-gram, There was significant difference in tensile bond strength as applying the bonding agent.

• Food Engineering Progress
• /
• v.13 no.4
• /
• pp.275-281
• /
• 2009

Sesame oils are partially mixed with other vegetable oils due to high price in a Korean market. To find out authentic sesame oil, a mass spectrometer-based electronic nose (MS-based E-nose) was used. Sesame oil (Se) was blended with soybean oil (So) or corn oil (Co) at the ratio (Se:So, Se:Co) of 97:3, 94:6, 91:9, 88:12 and 85:15, respectively. Intensities of each fragment from sesame oil by MS-based E-nose were completely different from those of soybean oil or corn oil. The obtained results were used for discriminant function analysis (DFA). Volatile organic components (VOC) of soybean oil or corn oil were similar to those of fresh air and DFA plot indicated a significant separation of pure sesame oil and pure other oil. The group of the mixed oil was seperated with that of sesame oil in DFA plot and the added amount of soybean oil to sesame oil was correlated with discriminant function first score (DF1). MS based E-nose system could be used as an efficient method to investigate the purity of sesame oil.

• Korean Journal of Heritage: History & Science
• /
• v.43 no.1
• /
• pp.236-259
• /
• 2010

The examination of sediment distribution in Seongryu Cave shows existence of rocks contrasting with Joseon Supergroup contrary to existing knowledge. Contrasting especially with the Taeback Group, Daegi Formation, Hwajeol Formation, and Dongjeom Formation has been observed. Unlike Taeback area where Dumugol Formation and Makgol Formation are observed on top of Dongjeom Formation, the rocks of this area are not clear in its separation between the two, so that it was named Geunnam Formation. Seongryu Cave has been developed in this Ordovician Geunnam Formation of the Joseon Supergroup. The cave, mostly horizontal, runs in the NE-SW direction, and contains three lakes. The main passage and branches are about 330 m and 540 m, respectively, making the total length of the cave about 870 m (show cave area = 270 m). Through underwater examination, about 85 m-long underwater passage was newly discovered. Various speleothem such as soda straw, stalactite, stalagmite, column, flowstone, rimston, cave shield, cave coral, curtain, bacon sheet, cave pearl, cave flower, helictite and calcite raft can be found in the cave. There are sections with constant flow of cavern water, but the majority of cavern water in the cave come from the ceiling. The most important discovery in this study is the presence of various speleothem in the submerged part of cave passages. Traces of corrosion and/or erosion can be observed in the speleothem in the submerge passage.

• Membrane Journal
• /
• v.31 no.3
• /
• pp.219-227
• /
• 2021

Molecularly imprinted membrane (MIM) is a porous polymer membrane incorporating with the molecular recognizing sites. In this study, the supporting P(AN-co-MA) asymmetric membrane was prepared by nonsolvent induced phase separation (NIPS) method. And then, MIM with lysozyme template sites was prepared using the surface imprinting method on the P(AN-co-MA) asymmetric membrane introducing a photoactive iniferter and then photo-grafting. The P(AN-co-MA) asymmetric membrane was modified with 3-chloropropyltrimethoxysilane and dithiocarbamate as a photoactive iniferter. To prepare a lysozyme imprinted membrane, the modified P(AN-co-MA) membrane was copolymerized with acrylamide as a functional momomer, N,N'-methylene bisacrylamide as a crosslinker and lysozyme as a template in the UV irradiation environment. The lysozyme imprinted MIM was analyzed by using SEM, FT-IR and EDS measurements. Its results confirm that all the P(AN-co-MA) membranes have an asymmetric structure and the iniferter group is successfully introduced on the membrane surface. The process parameters were adjusted to obtain MIM having the excellent lysozyme adsorption. The maximum lysozyme adsorption capacity reaches at 2.7 mg/g, which is 13 times higher than that of the non imprinted membrane (NIM). The permselective membrane filtration experiments of ovalbumin to lysozyme show that the P(AN-co-MA) MIM preferentially bounds a greater amount of lysozyme.