• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.321-325
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• 2011

The mutant strain M6 derived from Acetobacter sp. A9, which produces high levels of the bacterial cellulose derived by random mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine or UV treatment, was selected by a Hestrin and Schramm medium (HSB) plate assay. The characterization of the cellulose production was studied in flask culture to improve the productivity of bacterial cellulose by $Acetobacter$ sp. A9 and mutant strain M6. The yield of cellulose production was superior to mutant M6 than $Acetobacter$ sp. A9. Cellulose was produced 0.12 g $L^{-1}$ by $Acetobacter$ sp. A9 at HS medium and the mutant M6 produced the cellulose 6.95 g $L^{-1}$at HS medium. Strain M6 produced less amount of gluconic acid than A9, thus showing that cellulose production is negatively relted with the gluconic acid production.

• Journal of Dairy Science and Biotechnology
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• v.25 no.1
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• pp.15-20
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• 2007

Effects of gamma irradiation on chemical, microbiological, and immunological changes of Queso Blanco cheese were investigated. Although Queso Blanco cheese was made by heat pasteurization at 85$^{\circ}$C and addition of acid without lactic starter culture, total bacterial counts and lactic acid bacterial counts of control cheese were 7.65${\pm}$0.04 and 7.64${\pm}$0.02 log CFU/mL, respectively. It was thought that this microbial growth was due to the incomplete inactivation of raw milk by the heat treatment, resulting into growth during the pressing and the drying process. It demonstrated the possibility that if heat- and acid-resistant hazard microbes are present in raw milk, they can grow during the processes. Lactic acid bacterial counts of the irradiated cheese were 5.45${\pm}$0.02 log CFU/mL at 1kGy, 2.12${\pm}$0.12 log CFU/mL at 2kGy, and not detected at 3kGy or higher doses. The reduction of antigenicity by gamma irradiation was not found. It might be caused by the fact that most whey proteins of milk, a major antigen in milk, were already denaturated by heat process and removed during the draining.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2000.05a
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• pp.1-3
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• 2000

A kind of traditional herbal prescription, Sip-Jeon-Dae-Bo-Tang (TJ-48), has been reported to improve the general condition of cancer patients receiving chemotherapy and /or radiation therapy, and to accelerate hematopoietic recovery from bone marrow injury by mitomycin C. In the present studies, we found that hot-water extract from Atractylodes lancea DC. rhizomes contributed mainly to intestinal immune modulating activity of TJ-48 on Peyer's patch cells mediated-hematopoietic response. After the fractionation, ALR-5 II a-1-1, 5 II b-2-2 and 5 II c-3-1 were further purified from crude polysaccharide fraction. Chemical analyses of each fraction indicated that ALR-5 II a-1-1 mainly contained arabinogalactan fraction whereas ALR-5 II b-2-2 and 5 II c-3-1 mostly comprised pectic polysaccharide fractions as the active polysaccharide ingredients. In order to analyze the essential structure of the activity, ALR-5 II a-1-1 was treated by sequential enzymatic digestion using exo-${\alpha}$-L-arabinofuranosidase and exo-${\beta}$-D-(1\longrightarrow3)-galactanase. Based upon the results of chemical and MALDI-TOF-MS analyses and activity on the digested fractions, the galactosyl side chains consisting of 6-linked Galf and Galp over tetrasaccharide in ALR-5 II a-1-1 might be responsible for the potent intestinal immune modulating activity. To characterize moiety of ALR-5 II c-3-1 for the expression of activity, endo-${\alpha}$-D-(1\longrightarrow4)-polygal acturonase (GL-PGase) purified from dried leaves of Panax ginseng digested ALR-5 II c-3-1. The results of structural analyses and activity on the digested fractions showed that PG-2, which structurally resembles to rhamnogalacturonan II (RG II), and PG-3 (galacturono-oligosaccharides) contained potent intestinal immune modulating activity. Further purification of the other acidic fraction (ALR-5 II b-2-2) indicated that ALR-5 II b-2-2Bb showed that the most potent activity. ALR-5 II b-2-2Bb also contained the unusual component sugars characteristics in RG- II as well as PG-2 derived from ALR-5 II c-3-1, but it could not be digested with GL-PGase. The present studies of relationship between structures and intestinal immune modulating activity of the active polysaccharides purified from A. lancea DC. rhizomes suggested that neutral galactosyl chains consisting mainly of (1\longrightarrow6)-linked Galf and Galp, and RG- II -like moiety with unique component sugars, such as 2-Me-Xyl, 2-Me-Fuc, Api, AceA, Kdo and Dha should play an important role in the potent intestinal immune modulating action of A. lancea DC. rhizomes.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.15-15
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• 2011

As you know, boron compounds, borax ($Na_2B_4O_5(OH)_4{\cdot}8H_2O$) etc. were known thousands of years ago. As for natural boron, it has two naturally occurring and stable isotopes, boron 11 ($^{11}B$) and boron 10 ($^{10}B$). The neutron absorption $^{10}B$ is included about 19~20% with 80~81% $^{11}B$. Boron is similar to carbon in its capability to form stable covalently bonded molecular networks. The mass difference results in a wide range of ${\beta}$ values between the $^{11}B$ and $^{10}B$. The $^{10}B$ isotope, stable with 5 neutrons is excellent at capturing thermal neutrons. For example, it is possible to decrease a thermal neutron required for the nuclear reaction of uranium 235 ($^{235}U$). If $^{10}B$ absorbs a neutron ($^1n$), it will change to $^7Li+^1{\alpha}$ (${\alpha}$ ray, like $^4He$) with prompt ${\gamma}$ ray from $^{11}B$ $^{11}B$ (equation 1). $$^{10}B+^1n\;{\rightarrow}\;^{11}B\;{\rightarrow}\; prompt \;{\gamma}\;ray (478 keV), \;^7Li+4{\alpha}\;(4He)\;\;\;\;{\cdots}\; (1)$$ If about 1% boron is added to stainless steel, it is known that a neutron shielding effect will be 3 times the boron free steel. Enriched boron or $^{10}B$ is used in both radiation shielding and in boron neutron capture therapy. Then, $^{10}B$ is used for reactivity control and in emergency shutdown systems in nuclear reactors. Furthermore, boron carbide, $B_4C$, is used as the charge of a nuclear fission reaction control rod material and neutron cover material for nuclear reactors. The $B_4C$ powder of natural B composition is used as a charge of a control material of a boiling water reactor (BWR) which occupies commercial power reactors in nuclear power generation. The $B_4C$ sintered body which adjusted $^{10}B$ concentration is used as a charge of a control material of the fast breeder reactor (FBR) currently developed aiming at establishment of a nuclear fuel cycle. In this study for new boron compound, silicon boride ceramics for capturing thermal neutrons, preparation and characterization of both silicon tetraboride ($SiB_4$) and silicon hexaboride ($SiB_6$) and ceramics produced by sintering were investigated in order to determine the suitability of this material for nuclear power generation. The relative density increased with increasing sintering temperature. With a sintering temperature of 1,923 K, a sintered body having a relative density of more than 99% was obtained. The Vickers hardness increased with increasing sintering temperature. The best result was a Vickers hardness of 28 GPa for the $SiB_6$ sintered at 1,923K for 1 h. The high temperature Vickers hardness of the $SiB_6$ sintered body changed from 28 to 12 GPa in the temperature range of room temperature to 1,273 K. The thermal conductivity of the SiB6 sintered body changed from 9.1 to 2.4 W/mK in the range of room temperature to 1,273 K.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.534-541
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• 2009

The aim of this study was to evaluate the effects of gamma irradiation (${\gamma}$-irradiation) at doses of 15, 30 and 45 kGy on chemical composition, anti-nutritional factors, ruminal dry matter (DM) and crude protein (CP) degradibility, in vitro CP digestibility and to monitor the fate of true proteins of full-fat soybean (SB) in the rumen. Nylon bags of untreated or ${\gamma}$-irradiated SB were suspended in the rumens of three ruminally-fistulated bulls for up to 48 h and resulting data were fitted to a nonlinear degradation model to calculate degradation parameters of DM and CP. Proteins of untreated and treated SB bag residues were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Digestibility of rumen undegraded CP was estimated using the three-step in vitro procedure. The chemical composition of raw and irradiated soybeans was similar. Results showed that phytic acid in ${\gamma}$-irradiated SB at dose of 30 kGy was eliminated completely. The trypsin inhibitor activity of 15, 30 and 45 kGy ${\gamma}$-irradiated SB was decreased (p<0.01) by 18.4, 55.5 and 63.5%, respectively. From in sacco results, ${\gamma}$-irradiation decreased (p<0.05) the washout fractions of DM and CP at doses of 30 and 45 kGy, but increased (p<0.05) the potentially degradable fractions. Gamma irradiation at doses of 15, 30 and 45 kGy decreased (p<0.05) effective degradability of CP at a rumen outflow rate of 0.05 $h^{-1}$ by 4.4, 14.4 and 26.5%, respectively. On the contrary, digestibility of ruminally undegraded CP of irradiated SB at doses of 30 and 45 kGy was improved (p<0.05) by 12 and 28%, respectively. Electrophoretic analysis of untreated soybean proteins incubated in the rumen revealed that ${\beta}$-conglycinin subunits had disappeared at 2 h of incubation time, whereas the subunits of glycinin were more resistant to degradation until 16 h of incubation. From the SDS-PAGE patterns, acidic subunits of 15, 30 and 45 kGy ${\gamma}$-irradiated SB disappeared after 8, 8 and 16 h of incubation, respectively, while the basic subunits of glycinin were not degraded completely until 24, 48 and 48 h of incubation, respectively. It was concluded that ${\gamma}$-irradiated soybean proteins at doses higher than 15 kGy could be effectively protected from ruminal degradation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.35-44
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• 2014

This study was performed to investigate the anti-photoaging effects of Persimmon leaf tea(PLT) in hairless mice(SKH-1) exposed to UVB radiation. The animals were divided into non-treated group (normal, N) and UV-radiated groups. UV-radiated groups were divided into only UV-radiated group(control, C) and UV-radiated and PLT treated experimental groups[first extraction treated group(PLT-I), second extraction treated groupe(PLT-II), and third extraction treated group(PLT-III)]. Three PLT treated experimental groups of mice were treated with both oral administration(300mg/Kg B.W./day) and topical application (100 ul of 2% conc./mouse/day) for 4 weeks. Anti-photoaging effects of Persimmon leaf were evaluated by MTT assay, anti oxidative reaction, MMP immunohistochemistry, gelatin zymography assay and RT-PCR observations. Treatment with Persimmon leaf tea(PLT)-I, and -III groups decreased immunohistochemical density of matrix metalloproteinases(MMP)-3 and -9 related to degradation of extracellular matrix in skin. Especially, immunohistochemical density of MMP-2 decreased in PLT-I, -II and -III groups in skin. On the effects of antioxidant function on the treatment with Persimmon leaf tea(PLT), treatment of HaCaT cells with extracts of PLT-I and PLT-II had also significantly reduced intracellular ROS produced by UVB irradiation in a dose dependent manner(PLT-I, p<0.05, p<0.01, p<0.001; PLT-II, p<0.01, p<0.001). Gelatin zymography assay revealed that PLT-II and PLT-III (200 ug/ml) had inhibitory effect on MMP-9 expression in UVB-radiated HaCaT cells. Western blot analysis revealed that PLT-1, -II and -III groups down-regulates the expression of inflammatory associated genes(IL-$1{\beta}$) and PLT-1 and -II groups down-regulates the expression of TNF-${\alpha}$ in a dose dependent manner. Our study suggests that Persimmon leaf tea(PLT) extracts participates in inhibitory effects on the morphological and molecular experiments related to photoaging skin on UVB irradiated hairless mice.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.211-218
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• 2021

BACKGROUND: Fine particulate matter (PM_2.5) is produced by chemical reactions between various precursors. PM_2.5 has been found to create greater human risk than particulate matter (PM₁₀), with diameters that are generally 10 micrometers and smaller. Ammonia (NH₃) and nitrogen oxides (NOx) are the sources of secondary generation of PM_2.5. These substances generate PM_2.5 through some chemical reactions in the atmosphere. Through chemical reactions in the atmosphere, NH₃ generates PM_2.5. It is the causative agent of PM_2.5. In 2017 the annual ammonia emission recorded from the agricultural sector was 244,335 tons, which accounted for about 79.3% of the total ammonia emission in Korea in that year. To address this issue, the agricultural sector announced the inclusion of reducing fine particulate matter and ammonia emissions by 30% in its targets for the year 2022. This may be achieved through analyses of its emission characteristics by monitoring the PM_2.5 and NH₃. METHODS AND RESULTS: In this study, the PM_2.5 concentration was measured real-time (every 1 hour) by using beta radiation from the particle dust measuring device (Spirant BAM). NH₃ concentration was analyzed real-time by Cavity Ring-Down Spectroscopy (CRDS). The concentrations of ozone (O₃) and nitrogen dioxide (NO₂) were continuously measured and analyzed for the masses collected on filter papers by ultraviolet photometry and chemiluminescence. CONCLUSION: This study established air pollutant monitoring system in agricultural areas to analyze the NH₃ emission characteristics. The amount of PM_2.5 and NH₃ emission in agriculture was measured. Scientific evidence in agricultural areas was obtained by identifying the emission concentration and characteristics per season (monthly) and per hour.

• 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.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.93-99
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• 2002

Purpose : We intended to decrease late CNS reaction after radical radiotherapy for an intracranial germinoma by using combined neoadjuvant chemotherapy and involved-field radiotherapy. The efficacy in terms of its acute toxicity and short-term relapse patterns was analyzed. Materials and Methods : Eighteen patients were treated with combined neoadjuvant chemotherapy and radiotherapy between 1995 and 2001. The chemotherapy regimen used was the Children's Cancer Group (CCG) 9921A (cisplatin, cyclophosphamide, VP-16, vincristine) for 5 patients younger than 16 years, BEP (bleomycin, VP-16, cisplatin) for 12 patients, and EP (VP-16, cisplatin) for 1 patient. The radiotherapy covered the whole craniospinal axis for 5 patients, the whole brain for 1, and the partial brain (involved field) for 12. the primary lesion received tumour doses between 3,960 and 5,400 cGy. Results : The male to female ratio was 16:2 and the median age was 16 years old. The tumors were located in the pineal gland in 12 patients, in the suprasellar region in 1, in the basal ganglia In 1, in the thalamus in 1. Three patients had multiple lesions and ventricular seedings were shown at MRI. In 3 patients, tumor cells were detected in the cerebrospinal fluid and MRI detected a spinal seeding in 2 patients. The response to neoadjuvant chemotherapy was complete remission in 5 patients, partial remission in 12, and no response in 1. However, after radiotherapy, all except 1 patient experienced complete remission. The toxicity during or after chemotherapy greater than or equal to grade III was remarkable; hematologic toxicity was observed in 11 patients, liver toxicity in none, kidney toxicity in none, and gastrointestinal toxicity in one. One patient suffered from bleomycin-induced pneumonitis. Radiotherapy was therefore stopped and the patient eventually died of respiratory failure. The other 17 are alive without any evidence of disease or relapse during an average of 20 months follow-up. Conclusion : A high response rate and disease control was experienced, which was the same as observed other studies and the morbidity from chemotherapy-induced toxicity was similar. With these results, the results from adjuvant chemotherapy and involved-field radiotherapy cannot be concluded to be equal to those from extended-field radiotherapy. The long term follow-up study on later complications are required in order to draw definite conclusions on the optimal management with minimum side effects.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.207-216
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• 2000

Continuous measurements of radon progeny concentrations in the open atmosphere and measurements of meteorological parameters were performed in Tajeon, using a continuous gross alpha/beta aerosol monitor and a weather measuring equipment between July 1999 and July 2000. These data were analyzed for half-hourly, daily, and seasonal variations. The distribution of daily averaged equilibrium equivalent radon concentration$(EEC_{Rn})$ had an arithmetic mean value of $11.3{\pm}5.86Bqm^{-3}$ with the coefficient of variation of about 50% and the geometric mean was $10.3Bqm^{-3}$. The $EEC_{Rn}$ varies between 0.83 and $43.3Bqm^{-3}$, depending on time of day and weather conditions. Half-hourly averaged data indicated a diurnal pattern with the outdoor $EEC_{Rn}$ reaching a maximum at sunrise and a minimum at sunset. The pattern of the seasonal variation of the $EEC_{Rn}$ in Taejon had a tendency of minimum concentration occurring in the summer(July) and maximum concentration occurring in the late autumn(November). But the seasonal variation of the $EEC_{Rn}$ is expect to vary greatly from place to place. The outdoor $EEC_{Rn}$ was highly dependent on the local climate features. Particularly the $EEC_{Rn}$an rapidly drops less than $5Bqm^{-3}$ in case of blowing heavily higher than wind speed of $6msec^{-1}$, reversely the days with more than $30Bqm^{-3}$ were at a calm weather condition with the wind speed of lower than $1msec^{-1}$.