• Journal of Environmental Health Sciences
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• v.18 no.1
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• pp.1-5
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• 1992

A study was performed to measure the heavy metal concentrations of suspended particles in iron castings during February, 1990. The heavy metal concentrations were analyzed using patricles atomic absorption spectrophotometer. The results were as fellows 1. The concentrations of suspended paticles by casting process were at furnace 4.19mg/m$^{3}$ at pouring 2.93mg/m$^{3}$ at nonferrous furnace 3.90mg/m$^{3}$, at molding 1.17mg/m$^{3}$, jung ja 2.23mg/m$^{3}$, desanding 5.42mg/m$^{3}$, sand treatment 4.82mg/m$^{3}$, finishing 1,20mg/m$^{3}$. 2. Among the total of 8 iron casting workplaces, the concentrations Fe of furnace was 0.36mg/m$^{3}$, Cu of nonferrous furnace 0.02mg/m$^{3}$, Pb of pouring 0.02mg/m$^{3}$, Cr of desanding 0.01mg/m$^{3}$ and Mn of furnace 0.03mg/m$^{3}$.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.463-471
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• 1999

Magnesium($Mg^{2+}$) is one of the most abundant intracellular divalent cation. Although recent studies demonstrate that adrenergic receptor stimulation evokes marked changes in $Mg^{2+}$ homeostasis, the regulation of $Mg^{2+}$ by dopaminergic receptor stimulation is not yet known. In this work, we used dopaminergic agents to identify which type(s) of receptors were involved in the mobilization of $Mg^{2+}$ by dopaminergic receptor stimulation in the perfused rat hearts, isolated myocytes and circulating blood. The $Mg^{2+}$ content was measured by atomic absorbance spectrophotometry. Dopamine(DA), apomorphine(APO) and pergolide stimulated $Mg^{2+}$ efflux in the perfused rat hearts and these effects were inhibited by haloperidol or fluphenazine, nonselective dopaminergic antagonists. SKF38393, a selective doparminergic agonist, increased $Mg^{2+}$ efflux from the perfused hearts in dose dependant manners and SKF38393-induced $Mg^{2+}$ efflux was blocked by haloperidol. However, dopaminergic agonists-induced $Mg^{2+}$ efflux was potentiated in the presence of sulpiride or eticlopride, $D_2$-selective antagonist, from the perfused hearts. This increase of $Mg^{2+}$ efflux was blocked by haloperidol or imipramine. DA or pergolide increased in circulating $Mg^{2+}$ from blood. By contrast, PPHT stimulated $Mg^{2+}$ influx(a decrease in efflux) from the perfused hearts and circulating blood. PPHT-induced $Mg^{2+}$ influx was blocked by fluphenazine in the perfused hearts. DA-stimulated $Mg^{2+}$ efflux was inhibited by dopaminergic antagoinst in the isolated myocytes. In conclusion, the flux of $Mg^{2+}$ is modulated by DA receptor activation in the rat hearts. The efflux of $Mg^{2+}$ can be increased by $D_1$-receptor stimulation and decreased by $D_2$-receptor stimulation, respectively.

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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• pp.96-99
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• 1995

Addition of l00mM $MgSO_4$ to a cell culture after 54 hours resulted in a 2.4-fold increase in the sisomicin titre compared to a control to which no $MgSO_4$ was added, and a considerable amount of intracellular sisomicin was liberated outside the cells. The occurrence of product inhibition in fermentation was confirmed by a reduction in net sisomicin production with increasing amounts of added sisomicin without addition of $MgSO_4$. All added sisomicin was bound to sisomicin-free cells in the absence of $MgSO_4$, whereas approximately 40% of added sisomicin was bound with the addition of l00mM $MgSO_4$. Under conditions of no enzmye synthesis, maintained by adding chloramphenicol to exclude product repression, sisomicin was produced in the presence of 100 mM $MgSO_4$ but little sisomicin was produced in the absence of $MgSO_4$.

• Korean Journal of Community Nutrition
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• v.2 no.5
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• pp.687-694
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• 1997

This study investigated the effects of vitamin C supplementation on the nutritional iron status of 31 adolescent girls, aged 12-15 years, with low hemoglobin levels. They were randomly divided into four groups, and for two groups daily150mg or 900mg of L-ascorbic acid(AsA) was given in three equal doses at three meals during 9 weeks. To another group daily 60mg iron as ferrous sulfate was given in the same way as AsA. The control group was given sugar placebo. Body iron status was monitored through the determination of Hb, Hct, MCHC, and serum ferritin concentrations. Dietary AsA and iron intakes were measured from food consumption surveys performed by 3-day 24-hour recalls. The amount of absorbed iron was estimated from the model of Monsen et al. The average amounts of food iron for four groups were 12.3- 15.0mg and 11.1 - 18.9mg at initial and at final period of the supplementation trial, respectively. The tentatively estimated amount of absorbed iron was significantly increased in the 900mg AsA and iron supplementing groups, but not in the 150mg AsA and placebo groups. Both Hb and MCHC were improved to above normal levels in all groups except the placebo group. Hct was elevated only in the AsA 900mg group whose Hct was relatively lower than the other groups. Serum ferritin concentrations of the four groups, which were as low as 8.50 - 14.39ng/mL on average at the intial periods, augmented significantly to 20.18ng/mL and 26.63ng/mL in the 900mg AsA and iron groups, respectively. Serum ferritin was not elevated in either the AsA 300mg group or the placebo group. The above data indicated that the daily supplementaion of 150mg AsA to the meals containing 12-15mg iron per day promoted Hb levels of adolescent girls with low Hb, and the 900mg AsA supplementing improved not only Hb level but also body iron store. A supplementation of 60mg iron per day appeared to be slightly more effective in improving the iron status in comparison to the 900mg AsA supplement. (Korean J Community Nutrition 2(5) : 687-694, 1997)

• Journal of Korea Foundry Society
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• v.37 no.3
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• pp.63-70
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• 2017

In the present study, effects of an addition of Sn on the microstructure and corrosion behavior were investigated in Mg-4%Zn-(0-3)%Sn casting alloys. With an increase in the Sn content, the ${\alpha}-(Mg)$ dendritic cell size was reduced, whereas the total amount of precipitates increased due to the formation of the $Mg_2Sn$ phase. It was found in immersion and electrochemical corrosion tests that the addition of Sn has a detrimental effect on the corrosion resistance of the Mg-4%Zn alloy. Microstructural examinations of the corrosion product and the corroded surface indicated that an accelerated micro-galvanic effect by the $Mg_2Sn-phase$ particles and a less protective corrosion product on the surface were responsible for the increased corrosion rate at a higher Sn content.

• Journal of Environmental Science International
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• v.4 no.1
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• pp.81-90
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• 1995

In order to provide the basic information for the water quality modeling, the water pollution indicators of Sin stream and Keumho river flowing through Taegu city were measured, and the Periodical variations of these indicators were studied under the condition of stagnating for 19 days. For this experiment, three sampling sites(Sungpook bridge, Mutae bridge and Gangchang bridge) were selected. Sungpook bridge is located most down the Sin stream, Mutae bridge and Gangchang bridge are located on the lower Keumho river. The results were as follows. 1. The values of water pollution indicators measured at Mutae bridge were pH 8.7, TSS 51mg/1, TS 383mg/1, Cl- 60.68mg/1, turbidity 32FTU, DO 8.58mg/1, oxygen deficit 2.02mg/1, COD 16.32mg/1, organic carbon 13.60mg/1. 2. At Gangchang bridge located down more than Mutae bridge, the values of these indicators were pH 8.0, TSS 26mg/1, TS 737mg/1, Cl- 90.59mg/1, turbidity 37FTU,DO 3.49mg/1, oxygen deficit 7.11mg/1, COD 28.02mg/1, organic carbon 14.28mg/1. 3. At Sungpook bridge, the values of these indicators were pH 8.3, TSS 145mg/1, TS 344mg/1, Cl- 32.51mg/1, turbidity 60FTU, DO 6.53mg/1, oxygen deficit 4.07mg/1, COD 43.79mg/1, organic carbon 11.03mg/1. 4. At Mutae bridge and Sungpook bridge of which initial DOs were high, DOs have decreased under the condition of stagnating for 7 days and increased after that time. On the contrary, at Gangchang bridge of which oxygen deficit was very high(7.11mg/l), DO have increased under the condition of stagnating for 13 days and decreased after that time 5. All the samples showed the quick decrease of CODs and organic carbons under the condition of stagnating for 19 days. Nevertheless, at Sungpook bridge ·of which initial COD was yeW high(43.79mg/1), the value of COD measured at the last day of experiment was still high(21.35mg/1) because of a large quantity of reducing inorganic matters. 6. All the samples didn't show the distinct decrease of turbidities because of a large quantity of nonbiodegradable inorganic solids.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.57-62
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• 2005

Salt-tolerant transgenic Panax ginseng plants were produced by introducing the SAL1 geue (3'(2'), 5'-bis-phosphate nucleotidase) that confers tolerance to the salts through Agrobacterium tumefaciens co-cultivation. Cotyledon explants of immature ginseng zygotic embryos cultured on Murashige and Skoog medium lacking growth regulators formed somatic embryos directly with below 10%, but the 74% tranformation rate were observed at the treatment of phytohormone with 1.0 mg/l 2,4-D and 0.5 mg/l kinetin. Somatic embryos were initially cultured on MS medium supplemented with 250 mg/l cefotaxime for 3 weeks and subsequently subcultured five times to a medium containing 100 mg/l kanamycin and 250 mg/l cefotaxime. Upon development into the cotyledonary stage, these somatic embryos were transferred to on the medium containing 50 mg/l kanamycin and 10 mg/l gibberellic acid to induce germination and strong selection. Integration of the transgene into the plants was confirmed by polymerase chain reaction with specific primers. The ginseng transformants with well-developed shoots and roots were successfully acclimatized in a greenhouse when they were planted in soil.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.5
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• pp.315-323
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• 2008

To measure the mineral content of fishes, we collected 177 individuals from 53 fish species from the east (Pohang), west (Gunsan), and south (Tongyeong) coasts of Korea. The mean content of the macro mineral in a 100 g sample taken from the edible portion of each fish was (in descending order): P(207.4 mg), K(169.7 mg), Na(101.6 mg), Ca(44.4 mg), and Mg(30.4 mg). In comparison, the mean content of micro mineral in the fishes was (in descending order): Zn ($8.98{\mu}g/g$), Fe ($5.03{\mu}g/g$), Cu ($0.76{\mu}g/g$), Mn ($0.43{\mu}g/g$), and Ni ($0.08{\mu}g/g$). We could not observe clear regional variation in the mineral content of fish species. With regard to minerals considered essential for humans, the amount of Ca per sample (100 g) was the highest in the Scyliorhinus torazame (465.4 mg), and than followed by Ammodytes personatus (338.0 mg), Dasyatis akajei (267.4 mg), Raja kenojei (248.1 mg), Conger myriaster (174.1 mg), Clupanodon punctatus (86.8 mg), Muraenesox cinereus (81.2 mg), and Engraulis japonica (70.4 mg). The daily average intake of the mineral through the fishes consisted of P (100.6 mg), K (82.3 mg), Na (49.3 mg), Mg (14.8 mg), Zn (0.44 mg), Fe (0.24 mg), Cu (0.04 mg) and Mn (0.02 mg). The respective intakes of macro mineral (P, Mg, Na, Ca, K) from the fishes were about 14.4, 4.2, 3.3, 3.1 and 1.8% of the dietary reference intakes for Koreans (KDRIs) set by the Korean Nutrition Society. In comparison, the respective intakes of micro mineral (Cu, Zn, Fe, Mn) from the fishes were about 4.6, 4.4, 2.4, and 0.6% of the KDRIs.

• Journal of Animal Environmental Science
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• v.1 no.1
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• pp.77-82
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• 1995

In order to investigate the purification effects of livestock waste water, Modified Activated-Sludge Process(MASP) containing marine silica and volcanic ash-rock as the contact media and Sawdust-Soil Filter Method were used. The results obtained are as follows: 1. MASP which treated two metric tons' livestock waste water a day decreased BOD by 97.5% from 4,400.0mg/I to 108.8mg/I and SS by 98.0% from 5,335.0mg/I to 111.0mg/I. 2. MASP decreased BOD by 93.9% from 2,549.1mg/I to 156.6mg/I and SS by 96.3% from 3,521.9mg/I to 132.0mg/I when ten metric ton's livestock waste water was treated a day. 3. BOD and SS were decreased by 83.4% from 45.1mg/I to 7.5mg/I and by 83.4% from 47.5mg/I to 7.9mg/I when the supernatant layer treated by MASP was purified by Sawdust-Soil Filter Method.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.705-714
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• 2008

Three Mesh Screenning Reactors (MSRs) were operated in three different modes to investigate the effect of the mesh opening size and the filtrate flux on the removal of particulate matters and the production of soluble organic matters. The mesh opening size was $82{\mu}m$ (Mode 1), $61{\mu}m$ (Mode 2) and $38{\mu}m$ (Mode 3), respectively, and each mode has three different filtrate flux; $0.47m^3/m^2/d$, $0.95m^3/m^2/d$ and $1.42m^3/m^2/d$, respectively. TSS removal efficiency of mode 1, 2, and 3 fed with 191 mgTSS/L was 27%, 36%, and 60%, respectively. The SCOD concentration of 91mg/L in influent for the mode 1, 2, and 3 increased to 117 mg/L, 127 mg/L, and 155 mg/L, respectively. For the all MSRs, there was no significant effect of filtrate flux on the removal of particulate matters and the production of soluble organic matters. However, the mesh opening size greatly affected the removal of particulate matters and the production of soluble organic matters in wastewater. Three parallel A2O processes consisting of anaerobic, anoxic and aerobic reactors maintaining mixed liquor suspended solids (MLSS) of 3,000 mg/L were operated to investigate the effectiveness of MSR on the removal efficiencies of the organic matters, nitrogen, and phosphorus; MSR influent was introduced to System 1 (183 mgTSS/L, 324 mgTCOD/L, 87 mgSCOD/L, 45.2 mgTKN/L, and 6.6 mgTP/L) and MSR efluent was introduced to System 2 and 3(72 mgTSS/L, 289 mgTCOD/L, 141 mgSCOD/L, 40.2 mgTKN/L, and 4.2 mgTP/L). HRTs of the anaerobic reactors in systems 1, 2 and 3 were 1 h, 1 h and 0.6 h, respectively and anoxic reactors were 2 h in all systems. HRTs of the aerobic reactors in systems 1, 2 and 3 were 5 h, 3 h and 3 h, respectively. TSS concentration in effluent of both system 2 and 3 is about 8 mg/L and lower than that of system 1 effluent. Despite higher TCOD loading and SCOD loading, both Systems 2 and 3 had a greater TCOD and SCOD removal efficiency at 91% and 92% than System 1 was at 88% and 82%, respectively. The nitrification efficiency for system 2 was greater than observed for System 1 (99% verses 97%). The denitrification efficiency for systems 1, 2 and 3 was 78%, 88% and 87%, respectively. System 2 and 3 showed about 12% higher TN removal efficiency than system 1 (85% verses 73%). The effluent TP concentration for system 2 was less than observed for system 1 and 3.