• Journal of Life Science
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• v.20 no.6
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• pp.907-913
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• 2010

Human enteroviruses (HEV) are considered one of the major infectious causes of central nervous system infections such as aseptic encephalomeningitis in pediatrics. This study was focused on providing information related to genetic characteristics and diversities of HEV which prevailed between 2007 and 2009 in Busan, Korea. A total of 2,743 specimens were collected from children and screened for isolation of HEV by cell culture and RT-PCR. Among the specimins, 240 isolates were grouped into 21 different HEV serotypes using VP1 RT-PCR. The major etiological agents were CV-A6 and CV-B2 in 2007, E-6 and E-30 in 2008 and CV-B1 in 2009. The occurrence of HEV infections was the most frequent in the summer (May to August, 188 cases, 78.3%). Most of the isolates were identified from specimens from children under 10 years old, with the highest occurrence in the 2 to 4 year old range (15.2%). However, there were no significant differences between male and female children for the isolates. For analyzing genetic characterization, VP1 gene was amplified by RT-PCR and sequenced. The phylogenetic tree was established by Clustal W method using DNASTAR software. Using the sequence analysis of the VP1 region, it was classified into 2 groups; HEV-A and HEV-B. The HEV-A group contained 6 serotypes and sequences of 31 isolates were compared within each serotype. The HEV-B group contained 10 serotypes and the sequences of 41 isolates were compared within each serotype. Homology analysis of the VP1 region showed that the identity scores of HEV-A and B isolates were different. In conclusion, genetic divergences were observed among the isolates from children between 2007 and 2009 in Busan.

• Journal of Life Science
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• v.27 no.10
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• pp.1137-1144
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• 2017

The microalgae Chlorella vulgaris has been considered an important alternative resource for biodiesel production. However, its industrial-scale production has been constrained by the low productivity of the biomass and lipid. To overcome this problem, we isolated and characterized a potentially economical oleaginous strain of C. vulgaris via the random mutagenesis technique using UV irradiation. Two types of mass production systems were compared for their yield of biomass and lipid content. Among the several putatively oleaginous strains that were isolated, the particular mutant strain designated as UBM1-10 in the laboratory showed an approximately 1.5-fold higher cell yield and lipid content than those from the wild type. Based on these results, UBM1-10 was selected and cultivated under outdoor conditions using two different types of reactors, a tubular-type photobioreactor (TBPR) and an open pond-type reactor (OPR). The results indicated that the mutant strain cultivated in the TBPR showed more than 5 times higher cell concentrations ($2.6g\;l^{-1}$) as compared to that from the strain cultured in the OPR ($0.5g\;l^{-1}$). After the mass cultivation, the cells of UBM1-10 and the parental strain were further investigated for crude lipid content and composition. The results indicate a 3-fold higher crude lipid content from UBM1-10 (0.3%, w/w) as compared to that from the parent strain (0.1% w/w). Therefore, this study demonstrated that the economic potential of C. vulgaris as a biodiesel production resource can be increased with the use of a photoreactor type as well as the strategic mutant isolation technique.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.103-109
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• 2005

Isolation and primary culture technique of rabbit oral keratinocytes, and the study for effect of environmental factors on the cell growth were carried out in T75-flask. $1.92{\pm}0.59{\times}10^6$ viable cells were isolated by trypsin enzymatic digestion method from $0.25cm^2$ biopsy of rabbit oral mucosa. Primary culture with 10 mL of K-SFM containing 50 mg/L BPE, $5.0{\mu}g/L$ EGF and 0.15 mM $Ca^{2+}$ showed confluence after 8 days and doubling time was 2.54 days. Effect of medium types, medium volume and supplement types on the cell growth was investigated after the cultured keratinocytes had been harvested from primary confluence. Serum addition showed adverse effect and the increase of serum concentration didn't have an effect on the cell growth. The increase of medium volume decreased the cell growth. The increase of calcium concentration increased the cell growth and 2.0 mM was optimum value. In conclusion, when rabbit oral keratinocytes was cultured in T75-flask, the most effective conditions was to use 10 mL of K-SFM containing 50 mg/L BPE, $5.0{\mu}g/L$ EGF and 2.0 mM $Ca^{2+}$, and doubling time was 1.32 days. This study can provide the useful informations to develop a process and design a bioreactor for the culture of keratinocytes in human body like skin and cornea, as well as mucosa.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.344-356
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• 2005

There are normal inhabitants doing medically useful functions in the body. There are many kinds of bacteria performing specific functions in the oral cavity. Two strains of lactic acid bacteria were isolated from inhabitants of caries-free children's oral cavity, which inhibited the formation of artificial plaque by Streptococcus mutans and the production of volatile sulfur compounds by anaerobic bacteria. The isolates were identified by the test using API 50 CHL medium kit and 16S rDNA partial sequencing. 1. Two isolates were Gram-positive bacilli and produced hydrogen peroxide. 2. When Streptococcus mutans was cultured in the media, the mean weight of formed artificial plaque on the orthodontic wires was $124.4{\pm}30.4\;mg$, whereas being reduced to $5.2{\pm}2.0mg$ and $10.6{\pm}6.6mg$ in the media cultured with Streptococcus mutans and each isolate, respectively (p<0.05) 3. The number of viable cells of Streptococcus mutans was $3.4{\times}10^9$ per ml in the cultured solution, whereas those of Streptococcus mutans in the combined culture with each of isolates were $4.6{\times}10^8\;and\;2.4{\times}10^8$ per ml. 4. The optical density was 1.286 in the supernatant of Fusobacterium nucleatum after vortexing for 30minutes, whereas in the supernatant of combined Fusobacterium nucleatum and each isolate, they were reduced to 0.628 and 0.497, which the percentages of coaggregation between them were 29.4% and 57.8%, respectively 5. The optical density of Fusobacterium nucleatum precipitate was 1.794 in the culture media containing cysteine and $FeSO_4$, being reduced to 1.144 and 0.915 in the coaggregated precipitates of Fusobacterium nucleatum and each isolate. The optical density of Porphyromonas gingivalis precipitate was 1.932 in the culture media, being reduced to 1.170 and 1.266 in the coaggregated precipitates of Porphyromonas gingivalis and each isolate. 6. When two isolates were tested with API 50 CHL medium kit, those were identified Lactobaciallius salivarius and Lactobaciallius delbrueckii subsp. lactis. 7. The similarity values of 16S rDNA sequence between each of isolates and Lactobaciallius salivarius subsp. salicinius were 99.60% and 99.73%, respectively, meaning that isolates were Lactobaciallius salivarius subsp. salicinius. These results indicated that two strains isolated from caries-free children's saliva, which inhibited the formation of artificial plaque and the production of volatile sulfur compounds, were identified as Lactobaciallius salivarius subsp. salicinius.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1972.03a
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• pp.7-8
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• 1972

The effects of noise exposure are of two types: Nonauditory effects and auditory effects. Nonauditory effects of noise exposure are interference with communication by speech, sleeping and emotional behavior. The noise will cause the high blood pressure and rapid pulse, also that decrease the salivation and gastric juice. in experimentaly showed that the Corticoid hormon: Gonatotropic hormone were decrease and Thyrotropic hormoone is increase. Auditory effect of noise exposure. when the normal ear is exposed to noise at noise at hamful intensities (above 90㏈) for sufficiently long periods of time, a temoral depression of hearing results, disappearing after minutes or hours of rest. When the exposure longer or intesity greater is reached the Permanent threshold shift called noise-induced hearing loss. Hearing loss resulting from noise exposure presents legal as well as medical problems. The otologist who examines and evaluates the industrial hearing loss cases must be properly informed, not only concerning the otologic but also about the physical and legal aspects of the problems. The measurement of hearing ability is the most important part of a hearing conservation, both preplacement and periodic follow-up tests of hearing. The ideal hearing conservation program would be able to reduce or eliminate the hazardous noise at its source or by acoustic isolation of noisy working area and two ear protections (plugs and muff type) were developed for personal protection.

• Journal of Plant Biology
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• v.37 no.3
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• pp.387-394
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• 1994

Effects of environmental factors of light, temperature, nitrogen sources and water stress were analyzed quantitatively on the nodule formation and nitrogen fixation activity of autumn olive plant (Elaeagnu$ umbellala Thunb.) during the seedling growth. Seedlings showed the maximum nitrogenase activity of $72.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ in the early nodulation stage. The relative growth rate and T/R ratio changed from $1.60%{\cdot}d^{-1}$ and 1.12 in the earlier stage to $3.75%{\cdot}d^{-1}$ and 2.31 in the later stage, respectively. light conditions of 20-25, 1015 and 4-6% resulted in decreases of 41, 54 and 71% of the nitrogenase activity, respectively. Nodules incubated in 15, 20, 25 and $30^{\circ}C$ showed the activities of 5.4, 24.7, 51.6 and $58.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ respectively. Pretreatment with low temperature ($15^{\circ}C$) followed incubation at $30^{\circ}C$ attained higher nitrogenase activity ($66.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$) than that with higher temperature ($35^{\circ}C$). The oxygen pressure above 16 kPa is necessary for saturation of the nodule activity, but the activity was inhibited severely by physical impact such as the exision or isolation of nodules from the root. The relative activities of early nodules grown in pH 5.5, 6.5 and 8.0 were 89, 100 and 40% and those grown in 1 and 3 mM of $NO_3\;and\;NH_4$ were 6, 1 and 68, 50%, respectively. Watering levels of 20, 50 and 100 mL during the seedling growth resulted in 35, 120 and 8 mg of nodule formation and 33.6, 58.4 and $8.4\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ of the nitrogenase activity, respectively. Water stress with 86% decrease of soil water content caused temporary wilting point of leaf and a complete disappearance of nitrogenase activity of nodules, though the water content and transpiration rate in plant were reduced to 90 and 53%, respectively.tively.

• Journal of Plant Biology
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• v.38 no.1
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• pp.47-54
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• 1995

The present study performed the isolation of cytosolic ascorbate peroxidase (APX) isozymes and analyzed the pattern of their activity development and also investigated the change in some other enzyme activities related to the ascorbate-glutathione pathway from the senescing wheat leaves. The aim of this work is to examine the possibility that in the cytoplasm of wheat leaves the ascorbate-glutathione pathway p!ays a significant role in relation to leaf senescence involving an $H_2O_2$ accumulation and then to show the effect of benzyladenine (BA) on that pathway. During the leaf senescence characterized by increases in ChI breakdown and H202 accumulation under the 4-day dark incubation of matured leaf segments; i) no significant increase of total cytosolic APX was observed, ii) a dehydroascorbate reductase (DHAR) activity was decreased rapidly, iii) a slight increase of glutathione reductase (GR) activity occurred. In the BA-treated leaves; however, i) the total activity of APX increased conspicuously, ii) the decrease of DHAR activity was relatively inhibited, iii) the GR activity increase was more enhanced, and iv) the decrease of ascorbate content and the increase of H202 content were retarded as compared with those of control leaves. Three isozymes of cytosolic APX were found by using a native-electrophoretic gel in senescing wheat leaves and two of them occurred with major activity. In the developmental patterns of cytosolic APX isozymes, only two isozyme bands ("a" and "b") appeared with almost constant activity through 4 days of incubation in the control leaves, while one additional weak isozyme band ("c") and a little increase of "b" isozyme activity were detected in the BA-treated leaves. EspeciaUy, the development of "a" isozyme activity increased remarkably compared with that of control leaves. The increased capacity for peroxide scavenging due to the enhanced activity of all 3 enzymes (APX, DHAR, GR) participating in the ascorbate-glutathione pathway in BA-treated leaves suggested that this pathway might playa significant role in the processes related to the wheat leaf senescence.scence.

• Food Science and Preservation
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• v.22 no.3
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• pp.437-442
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• 2015

In a continuing screening of selected medicinal plants native to South Korea, the antioxidant and pancreatic lipase inhibitory activities of an aqueous methanolic extract from the heartwood of Aquilaria agallocha were investigated. Eighty percent of the methanolic extract of A. agallocha was further divided into $CH_2Cl_2$, EtOAc and n-BuOH in order to yield four solvent-soluble portions, namely $CH_2Cl_2$-soluble, EtOAc-soluble, n-BuOH-soluble and $H_2O$ residue. The antioxidant properties were evaluated by employing radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radicals, while the anti-obesity efficacy of A. agallocha extracts and solvent-soluble portions were tested by porcine pancreatic lipase assay. All tested samples showed dose-dependent radical scavenging and pancreatic lipase inhibitory activities. Among the tested extracts and solvent-soluble portions, the $CH_2Cl_2$-soluble portion showed much higher radical scavenging activity and pancreatic lipase inhibitory properties when compared with other solvent-soluble portions. This result suggested that there was a significant relationship between the total phenolic content and biological efficacies, and A. agallocha extract might be considered as a new potential source of natural antioxidants and as a pancreatic lipase inhibitory source. A more systematic investigation of this biomass will be performed for further investigation of activity against antioxidative and anti-obesity effects.

• Korean Journal of Agricultural Science
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• v.22 no.2
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• pp.188-196
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• 1995

To obtain useful mould strain in soybean fermentation industry, we collected conventional Meju all over the Korea and tested existance of aflatoxin in Meju collected. Also, we measured distribution of microorganism and enzyme activity of Meju and isolated Aspergillus oryzae O4-5 as a industrially useful mould. The results obtained were summarized as follows: 1. Aflatoxin was not detected by EZ-Screen Test Kit and HPLC analysis in various Meju sample collected all over the Korea from 1994.12 to 1995.2. 2. Colony forming units(CFU) of mould, yeasts, aerobe, and anaerobe were $1.3{\times}10^4-2.8{\times}10^6$, $1{\times}10^2-1.5{\times}0^6$, $2.0{\times}10^7-8.0{\times}10^8$ and $3.0{\times}10^6-7.3{\times}10^8$ per gram of Meju, respectively, indicating that CFU inter Meju samples were varied with big difference. 3. The activities of ${\alpha}$-amylase and gluco-amylase were 5-80 units and 2-34 units per g of Meju, respectively. It was shown that enzyme activity was varied depending on where the Meju was collected. 4. The activities of acidic, neutral and alkaline protease were 5-33 units, 5-302 units and 5-363 units per g of Meju, respectively. Acidic protease of Improved Meju made by D-Company was higher than that of conventional Meju as 66 units per g of Meju. 5. CNU O4-5 strain selected as a noble strain could produce amylase and protease in high level, and identified as a strain that belongs to Aspergillus oryzae. 6. The activities of acidic and neutral protease of Aspergillus oryzae CNU O4-5 strain isolated were about 10% higher than those of Aspergillus oryzae JM which has been used in soybean fermentation industry. Amylase activity of CNU O4-5 strain was similar to Aspergillus oryzae JM.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.528-533
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• 2009

In the current study, the mesenchymal stem cells (MSCs) isolated and propagated from the human umbilical cord blood (UCB) were tested for their capabilities of differentiation into chondrocytes in vitro. The mesenchymal progenitor cells (MPCs) collected from UCB were cultured in a low glucose DMEM medium with 10% FBS, L-glutamine and antibiotics. The human MSC colonies were positively stained by PAS reaction. When the immunophenotypes of surface antigens on the MSCs were analyzed by fluorescence-activated cell sorter (FACS) analysis, these cells expressed positively MSC-related antigens of CD 29, CD44, CD 90 and CD105, whereas they did not express antigens of CD14, CD31, CD34, CD45, CD133 and HLA-DR. Following induction these MSCs into chondrocytes in the chondrogenic differentiation medium for 3 weeks or more, the cells were stained positively with safranin O. We clearly confirmed that human MSCs were successfully differentiated into chondrocytes by RT-PCR and immunofluorescent stain of type-II collagen protein. These data also indicate that the isolation, proliferation and differentiation of the hUCB-derived MSCs in vitro can be used for elucidating the mechanisms involved in chondrogenesis. Moreover this differentiation technique can be applied to developing cell-based tissue regeneration or repair damaged tissues.