• Journal of Food Hygiene and Safety
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• v.24 no.3
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• pp.189-193
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• 2009

The purpose of this study was to investigate the antimicrobial activities of natural antimicrobials (10 formulas, $F1{\sim}F10$) against yeasts in functional beverages. The growth rates of yeasts were different with the ten different natural antimicrobial formulas tested. Yeasts grew for 14 days and the antimicrobial effect was observed between 14 and 18 days. Levels of S. cerevisiae, Z. bailii, and P. membranaefaciens were reduced to the limit of detection (ND) < 10 CFU/mL) after 28 days. Resistance against the antimicrobial effect was greatest for P. membranaefaciens, which grew to a level of $0.12{\sim}1.48\;\log_{10}\;CFU$/mL after 14 days and was reduced to a level of $1.61{\sim}3.55\;\log_{10}\;CFU$/mL after 28 days. The resistance of C. albicans was also high with a growth level of $0.13{\sim}1.28\;\log_{10}\;CFU$/mL after 14 days and reduction to $1.51{\sim}5.30\;\log_{10}\;CFU$/mL after 28 days. The antimicrobial effect of F10 was strongest for P. membranaefaciens. Every treatment reduced the microbial levels to $2.68{\sim}5.62\;\log_{10}\;CFU$/mL after 6 months. F2, F4, F5, F6, and F10 reduced the C. albicans level to ND after 28 days while F1, F3, F8, and F9 reduced yeasts to the ND level after 6 months. The antimicrobial activities observed here will be useful for development of natural antimicrobials.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.457-474
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• 2003

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.

• KSBB Journal
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• v.23 no.5
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• pp.375-380
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• 2008

We made an experiment of keeping extension of raw and semi-dried flounder (Pleuronectes herzensteini). Effect of with(WG) or without gill (OG), drying degree (20% drying：20D, 40% drying：40D) and storage temperature (5 and $10^{\circ}C$) and 0.1% chitosan-ascorbate (CA) treatment of vacuum packaging flounder on growth of contaminated microorganism during storage for 10 days were investigated. Total aerobacter (TA) in the OG-treated raw flounder was $0.3{\sim}0.5$ log cycle lower than that of WG-treated flounder and also, number of coliform (CF) and E. coli (CO) in OG were lower compared with WG. Number of TA,. Especially, the TA was $0.42{\sim}1.20$ log cycle lower compared with raw flounder. The TA of the raw flounder stored at $5^{\circ}C$ compared to $10^{\circ}C$ was $0.6{\sim}1.3$ log cycle lower. The growth of total aerobacter, coliform (and E. coli separated from raw flounder in tryptic soy broth were completely inhibited by 0.1% CA. But the growth of TA in the raw and 20% dried flounder was 1.5 log cycle inhibited by 0.1% CA, and the growth of CF and CO were also slightly inhibited. We did value raw sample that treated CA 0D and 20D, and did vaccum packaging at the $10^{\circ}C$ for 10 days, Sensory quality such as appearance, freshness, and texture and overall acceptability after cooking of the 0.1% CA-treated raw and 20% dried flounder were evaluated from good to very good, while CA non-treated products were evaluated to moderate.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.124-125
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• 2002

Two experiments were conducted to investigate the response of chitosan supplementation in diet on the major economic traits of broiler in two different breeds. In the both experiments, the Arbor Acres and Ross breeds were used as experimental stocks and two groups were assigned in each breed. The control group birds(CON) were fed with basal diet only and the experimental group birds(EXP) were fed with basal diet added with 10.5mg chitosan/bird/day. The chitosan was supplied to birds from day-old in experiment 1 and from 15-day-old in experiment 2. In experiment 1, the mean body weight at 35-day-old were significantly(P〈0.05) heavier by 121.2 g and 243.7 g in the EXP groups than in the CON groups of Arbor Acres and Ross, respectively. Whereas, the mean body weights at 35-day-old in experiment 2 were lighter by 91.7 g and 70.2 g in the EXP groups than in the CON groups of Arbor Acres and Ross, respectively : however, the comparisons between breeds in the mean body weight at 35-day-old did not show significant difference in each other in both breeds. In the mean feed conversion ratio of Arbor Acres from 14 to 35-day old in experiment 1, it did not show significant difference between EXP and CON groups although the feed conversion ratio of the EXP group of Ross was significantly higher(P〈0.05) than the CON group. In experiment 2, the feed conversion ratios from 14 to 35-day-old did not show significant differences between the two breeds. The percentage of mean abdominal fat depositions of EXP groups in both breeds In experiment 1 were significantly(P〈0.05) higher than those of CON groups. And the percentage of mean abdominal fat deposition of Ross was significantly(P〈0.05) lower than that of Arbor Acres. In experiment 2, the percentage of mean abdominal fat depositions did not show significant difference between EXP and CON groups in both breeds. Whereas, the interaction effects between breed and experimental groups on the above economic traits did not show significant in both experiments.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.164-169
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• 1999

This study was carried out in an attempt to select chemicals such as zeolite granules, chitosan, wood-vinegar, $Ca(OCl)_2$, NaOCl, against bacterial brown blotch caused by Pseudomonas tolaasii on Flammulina velutipes in laboratory and mushroom unit. Results obtained using these chemicals were summarized. Inhibitory effect on $Ca(OCl)_2$ and wood-vinegar with 0.5% concentration was shown to caual pathogen, P. tolaasii, by slight damage on the mycelial growth of F. velutipes. Those materials were recognized as promising one for control of bacterial brown bloth on F. velutipes. Disease incidence in control was the highest value as 43.8%; whereas chemical treatment was estimated as 14.6% with 0.5% of $Ca(OCl)_2$. Disease incidence was inhibited about 20% in chemical treatment with 0.5% of wood-vinegar, 1.0% of $Ca(OCl)_2$, and 26.1% with 1.0% of wood-vinegar. For the inhibition effects of chemical concentrations, it was effective at the low concentration which was 0.5% rather than that of 1.0%. Quality of mushrooms was significantly improved, and yields was also increased by 30% in the chemical treatment. In case of $Ca(OCl)_2$ treatment at 1.0% concentration, the yields was increased by 35.6% showed the highest value among tested chemicals. However, the overall effects including disease incidence, quality and yields suggests that $Ca(OCl)_2$ is relatively more effective than wood-vinegar, and the optimal concentration controlling the disease was $0.5{\sim}1.0%$ with $Ca(OCl)_2$ and 0.5% with wood-vinegar.

• Food Science and Preservation
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• v.17 no.4
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• pp.519-525
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• 2010

Kwamegi, a traditional Korean food, is made from the flesh of Pacific saury (the fish Cololabis saira semi-dried in a cold wind off the sea, and is well known in Korea as a valuable health food. Recently, several functional materials have been developed for supplementation of Kwamegi. Here, we compared and analyzed the nutrient composition, including overall composition and mineral, vitamin, fatty acid, and amino acid levels, of several commercial Kwamegi samples prepared with addition of functional components (unsupplemented Kwamegi, Kwamegi with chitosan, and Kwamegi overlaid with gold leaf). The levels of moisture (26.4-30.8%), crude protein (29.1-32.7%), and crude ash (1.6-1.9%) did not differ greatly among samples. However, the crude lipid content of Kwamegi overlaid with gold leaf (KOGL, 32.2%) was greater than that of untreated Kwamegi (CK, 24.5%) or of Kwamegi with added chitosan (KAC, 22.9%). The levels of vitamin $B_2$ (1.8-2.0 mg/100 g) and vitamin C (6.6-6.7 mg/100 g) did not differ greatly among Kwamegi samples. However, CK had a higher vitamin A content and a greater vitamin A potency than did KAC or KOGL. The various Kwamegi samples tested contained similar levels of fatty acids and amino acids. In conclusion, no particular differences in nutrient composition were evident when commercial Kwamegi samples supplemented with functional ingredients were tested

• Progress in Medical Physics
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• v.9 no.3
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• pp.155-162
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• 1998

Ho-l66 was produced by neutron reaction in a reactor at the Korea Atomic Energy Institute (Taejon, Korea). Ho-l66 emits a high energy beta particles with a maximum energy of 1.85 MeV and small proportion of gamma rays (80 keV). Therefore, the radiation absorbed dose estimation could be based on the in-vivo quantification of the activity in tumors from the gamma camera images. Approximately 1 mCi of Ho-l66 in solution was mixed into the flood phantom and planar scintigraphic images were acquired with and without patient interposed between the phantom and scintillation camera. Transmission factor over an area of interest was calculated from the ratio of counts in selected regions of the two images described above. A dual-head gamma camera(Multispect2, Siemens, Hoffman Estates, IL, USA) equipped with medium energy collimators was utilized for imaging(80 keV${\pm}$10%). Fifty-nine year old female patient with hepatoma was enrolled into the therapeutic protocol after the informed consent obtained. Thirty millicuries(110MBq) of Ho-166-CHICO was injected into the right hepatic arterial branch supplying hepatoma. When the injection was completed, anterior and posterior scintigraphic views of the chest and pelvic regions were obtained for 3 successive days. Regions of interest (ROIs) were drawn over the organs in both the anterior and posterior views. The activity in those ROIs was estimated from geometric mean, calibration factor and transmission factors. Absorbed dose was calculated using the Marinelli formula and Medical Internal Radiation Dose (MIRD) schema. Tumor dose of the patient treated with 1110 MBq(30 mCi) Ho-l66 was calculated to be 179.7 Gy. Dose distribution to normal liver, spleen, lung and bone was 9.1, 10.3, 3.9, 5.0 % of the tumor dose respectively. In conclusion, tumor dose and absorbed dose to surrounding structures were calculated by daily external imaging after the Ho-l66 therapy for hepatoma. In order to limit the thresholding dose to each surrounding organ, absorbed dose calculation provides useful information.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1309-1315
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• 2000

Objectives : We performed an in vivo experiment to investigate the effect of $^{166}Holmium$ and $^{166}Holmium$-chitosan complex($^{166}Ho$-CHICO) on the normal brain of rats and to determine the sublethal dose of $^{166}Ho$-CHICO. Materials and Methods : $^{166}Ho$ is a beta and gamma ray emitter. $^{166}Ho$-CHICO is a novel radio-pharmaceutical complex with chitosan to facilitate the transport of $^{166}Ho$ obtained from Korea Atomic Energy Research Center(Taejon, Korea). It is in acidic form and becomes gel state at alkaline pH. One hundred and seventy consecutive rats were divided into four groups : $^{166}Ho$ treated(n＝50), $^{166}Ho$-CHICO treated(n＝57), saline treated(n＝5) and chitosan treated(n＝5) groups. $^{166}Ho$ and $^{166}Ho$-CHICO were injected into the rat brain stereotactically with various doses of 0.1mCi/$20{\mu}l$, 0.2mCi/$20{\mu}l$, 0.3mCi/$20{\mu}l$, and 0.4mCi/$20{\mu}l$ using an automated microinjector. Nuclear imaging, histopathological and hematological studies were performed in 10 rats in each group at 1 day, 3days, 7 days, 1 month and 3 months after the injections. Results : An infiltration of inflammatory cells and necrotic changes were noted in $^{166}Ho$ treated group at 1 week after the injection. A wedge-shaped tissue defect due to necrosis, lined with infiltrated glial cells in $^{166}Ho$ treated group and a cystic defect lined with reactive astroglial cells in $^{166}Holmium$-CHICO treated group at 3 months after the injection were observed. $^{166}Ho$ alone without chitosan leaked out and caused necrotic lesion on the cerebral surface but $^{166}Holmium$-CHICO treated group did not show this feature. As the dose of $^{166}Ho$ increased, the mortality rates were also increased. The mortality rate of the $^{166}Holmium$-CHICO group was higher than the $^{166}Ho$ treated group at a dose of 0.4mCi/$20{\mu}l$/300g. There was no detectable radioactivity due to the leakage or extravasation from the injected site of the brain on the scintigraphy performed at 1 hour, 24 hours and 48 hours after the injection. There was also no detectable activity of $^{166}Holmium$-CHICO in other organs including spleen, liver and kidney. Conclusions : $^{166}Ho$-CHICO did not leak out to the critical cortical surface of the brain from the injection site and induced radiation changes of the parenchyma around the injection site without cortical damage. The sublethal dose of $^{166}Ho$-CHICO for the normal brain in rats was determined to be 0.2mCi/$20{\mu}l$/300g.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.344-350
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• 2003

In this paper, we propose a novel sharing method ordering the events occurring between users collaborated with the common telecomputing environment. We realize the sharing method with multimedia data to improve the coworking effect using teleprocessing network. This sharing method advances the efficiency of communicating projects such as remote education, tele-conference, and co-authoring of multimedia contents by offering conveniences of presentation, group authoring, common management, and transient event productions of the users. As for the conventional sharing white board system, all the multimedia contents segments should be authored by the exclusive program, and we cannot use any existing contents or program. Moreover we suffer from the problem that ordering error occurs in the teleprocessing operation because we do not have any line-up technology for the input ordering of commands. Therefore we develop a method of retrieving input and output events from the windows system and the message hooking technology which transmits between programs in the operating system In addition, we realize the allocation technology of the processing results for all sharing users of the distributed computing environment without any error. Our sharing technology should contribute to improve the face-to-face coworking efficiency for multimedia contents authoring, common blackboard system in the area of remote educations, and presentation display in visual conference.

• Food Science and Preservation
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• v.16 no.2
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• pp.223-229
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• 2009

The effects of 0.01%(w/v) chitosan-ascorbate(CA) and 10 ppm morea on the number of total microbes, Escherichia coli levels, and growth of food poisoning bacteria in dombaeki during storage at $10^{\circ}C$ over 6 days were investigated. Total microbes in meat, cartilage, and skin of untreated samples increased by 4.24, 3.81, and 2.20 logs compared to the zero timepoint, respectively, but, in CA-treated samples, counts fell by 2.66, 2.37, and 1.24 logs. Total microbial levels in morea-treated meat, cartilage, and skin showed similar tendencies but the effects were slightly less than seen in CA-treated samples. E. coli numbers in CA-treated meat, cartilage, and skin stored for 6 days decreased by 1.69, 1.25, and 1.52 logs respectively, compared with control samples. Morea-treated samples showed similar falls, but the effects were again slightly less than seen after CA-treatment. Both Salmonella and Vibrio parahaemolyticus were detected in untreated meat stored for 3 or 6 days. Food poisoning bacteria were found in both untreated and morea-treated samples stored over 6 days. However, no such bacteria were detected in CA-treated samples. Also, CA-treated meat, cartilage, and skin showed low degrees of degeneration. Thus, CA treatment enhanced shelf-life and dombaeki quality by inhibiting microorganism growth and tissue breakdown during storage.