• Korean Journal of Medicinal Crop Science
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• v.24 no.4
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• pp.294-302
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• 2016

Background: Crop rotation plays an important role in improving soil chemical properties, minimizing the presence of disease pathogens, and assists in neutralizing autotoxic effects associated with allelochemicals. Methods and Results: Five rotation crops of sudan grass, soybean, peanut, sweet potato, and perilla were cultivated for one year with an aim to reduce yield losses caused by repeated cropping of ginseng. In 2-year-old ginseng grown in the same soil as a previous ginseng crop, stem length and leaf area were reduced by 30%, and root weight per plant was reduced by 56%. Crop rotation resulted in a significant decrease in electrical conductivity, $NO_3$, and $P_2O_5$ content of the soil, whereas organic matter, Ca, Mg, Fe, Cu, and Zn content remained-unchanged. Soil K content was increased following crop rotation with sudan grass and peanut only. Rotation with all alternate crops increased subsequent ginseng aerial plant biomass, whereas root weight per plant significantly increased following crop rotation with perilla only. A significant positive correlation was observed between root rot ration and soil K content, and a significant negative correlation was observed between ginseng root yield and the abundance of actinomycetes. Crop rotation affected the soil microbial community by increasing gram negative microbes, the ratio of aerobic microbes, and total microbial biomass whereas decreases were observed in actinomycetes and the ration of saturated fatty acids. Conclusions: In soil exhibiting crop failure following replanting, crop rotation for one year promoted both soil microbial activity and subsequent ginseng aerial plant biomass, but did not ameliorate the occurrence of root rot disease.

• The Korean Journal of Physiology
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• v.26 no.2
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• pp.113-122
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• 1992

It is well known that chromaffin cells of adrenal medulla secrete catecholamine in response to sympathetic nerve activation and the influx of $Ca^{2+}$ through the voltage dependent $Ca^{2+}$ channels (VDCC) in the cell membrane do a major role in this secretory process. In this study, we explored the effect of divalent cations on VDCC of rat chromaffin cells. Rat (Sprague-Dawley rat, 150-250 gm) chromaffin cells were isolated and cultured. Standard giga seal, whole cell recording techniques were employed to study $Ca^{2+}$ current with external and internal solutions that could effectively isolate VDCC currents $(NMG\;in\;external\;and\;TEA\;and\;Cs^{2+}\;in\;internal\;solution)$. The voltage dependence and the inactivation time course of VDCC in our cells were identical to those of bovine chromaffin cells. A persistent inward current was first activated by depolarizing step pulse from the holding potential (H.P.) of -80 mV to -40 mV, increased to maximum amplitude at around +10 mV, and became smaller with progressively higher depolarizing pulses to reverse at around +60 mV. The inactivation time constant $(\tau)$, fitted from the long duration test potential (2 sec) was $1295.2{\pm}126.8$ msec $(n=20,\;1\;day\;of\;culture,\;mean\;{\pm}S.E.M.)$ and the kinetic parameters were not altered along the culture duration. Nicardipine $(10\;{\mu}M)$ blocked the current almost completely. Among treated divalent cations such as $Cd^{2+},\;Co^{2+},\;Ni^{2+},\;Zn^{2+}\;and\;,Mn^{2+},\;Cd^{2+}$ was the most potent blocker on VDCC. When the depolarizing step pulse from -80 mV to 10 mV was applied, the equilibrium dissociation constant $(K_d)$ of $Cd^{2+}\;was\;39\;{\mu}M,\;K_d\;of\;Co^{2+}\;was\;100\;{\mu}M\;and\;K_d\;of\;Ni^{2+}];was];780{\mu}M.$ The principal findings of this study are as follows. First, the majority of $Ca^{2+}$ channels in rat chromaffin cells are well classified to L-type $Ca^{2+}$ channel in the view of kinetics and pharmacology. Second, all divalent cations tested could block the $Ca^{2+}$ current and the most potent blocker among the tested was $Cd^{2+}$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.98-104
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• 1987

Studies were carried out to determined the optimal conditions of processing and changes in trypsin indigestible substrate(TIS) and in vitro protein digestibility of paddy grasshopper(Oxya chinensis formosana) under various drying conditions. The multienzyme assy and amino acid compositions were used to predict the quality changes of dried products. The in vitro protein digestidility of defatted products were higher than that of sun and hot air dried products. This results indicated that heat processing is decreased the digestibility, but is increased the TIS contents of dried samples. Amino acid composition of the products was comparable to the ANRC casein scoring pattern. The protein was espeoially low in the amount of lysine, tryptophan and methionine, but high in the quantity of aspartic acid, glutamic acid and arginine indicating that it could be a difference of the dry processing. C-PER and DC-PER were 2.65 and 2.44, respectively, in the defatted and freeze dried products and 2.49 and 2.30, respectively, in hot air dried products. From the these results, it could be confirmed that defatted and freeze dried products might be utilized with feed or foodstuff, unless the toxic substances were no longer detectable.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.745-764
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• 2023

In the Republic of Congo, Banded iron formations (BIFs) occur in two areas: the Chaillu Massif and the Ivindo Basement Complex, which are segments of the Archean Congo craton outcropping in the northwestern and southwestern parts of the country. They show interesting potential with significant mineral resources reaching 2 Bt and grades up to 60% Fe. BIFs consist mostly of oxide-rich facies (hematite/magnetite), but carbonate-rich facies are also highlighted. They are found across the country within the similar geological sequences composed of amphibolites, gneisses and greenschists. The Post-Archean Australian Shale (PAAS)-normalized patterns of BIFs show enrichment in elements such as SiO₂, Fe₂O₃, CaO, P₂O₅, Cr, Cu, Zn, Nb, Hf, U and depletion in TiO₂, Al₂O₃, MgO, Na₂O, K₂O, Sc, Th, Ba, Zr, Rb, Ni, V. REE diagrams show slight light REEs (rare earth elements; LREEs) compared to heavy REEs (HREEs), and positive La and Eu anomalies. The lithological associations, as well as the very high (Eu/Eu^*)_SN ratios> 1.8 shown by the BIFs, suggest that they are related to Algoma-type BIFs. The positive correlations between Zr and TiO₂, Al₂O₃, Hf suggest that the contamination comes mainly from felsic rocks, while the absence of correlations between MgO and Cr, Ni argues for negligeable contributions from mafic sources. Pr/Pr^* vs. Ce/Ce^* diagram indicates that the Congolese BIFs were formed in basins with redox heterogeneity, which varies from suboxic to anoxic and from oxic to anoxic conditions. They were formed through hydrothermal vents in the seawater, with relatively low proportions of detrital inputs derived from igneous sources through continental weathering. Some Congolese BIFs show high contents in Cr, Ni and Cu, which suggest that iron (Fe) and silicon (Si) have been leached through hydrothermal processes associated with submarine volcanism. We discussed their tectonic setting and depositional environment and proposed that they were deposited in extensional back-arc basins, which also recorded hydrothermal vent fluids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.96-101
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• 2003

This study was done to analyze the contents of minerals, to compare the measured values of calcium and the labeled values in food labeling and to analyze the ratio of calcium to other minerals in 43 calcium-fortified Food products sold in markets in Seoul, Korea. Content of minerals such as Ca, P, Mg, Na, K, Fe, Cu, Zn was measured by atomic absorption or colorimetric method after dry-ashing or wet-ashing. The measured values of calcium were ranged 65.5~343.9% of the labeled values in 43 calcium-fortified products. In 21 calcium-fortified food products, the measured calcium values were ranged 120～160% of the labeled values, and in three drinks those were less than 80% of the labeled, which is not acceptable to the food regulation. The ratios of Ca:P were 2.63$\pm$1.99 (mean$\pm$SD) in grain Products, 1.79$\pm$0.39 in Ramyuns, 2.80$\pm$0.53 in retort pouch food products and 8.35$\pm$12.87 in drinks. The Ca:Fe ratios were 126.33$\pm$44.36 in grain products, 130.65$\pm$34.67 in Ramyuns, 120.31$\pm$71.15 in retort pouch food products and 700.25$\pm$553.70 in drinks. The ratios of Ca:Mg were 11.86$\pm$5.40 in grain products, 9.29$\pm$1.34 in Ramyuns, 9.09$\pm$2.09 in retort pouch food products and 32.50$\pm$41.35 in drinks. The P:Mg ratios were 4.11$\pm$1.54 in grain products, 4.17$\pm$0.67 in Ramyuns, 2.58$\pm$0.45 in retort pouch food Products and 2.59$\pm$2.50 in drinks. These results suggest calcium contents and the ratio of calcium contents to other minerals in calcium-fortified food products should be strictly controlled.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.923-929
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• 2010

This study was conducted to investigate the relations between soil chemical properties and Korean raspberry (Rubus coreanus Miq.) growth. Soils were collected from 54 sampling sites in 1 to 6 years old Korean raspberry cultivation fields (RCFs) at Gochang-gun, Jeollabuk-Do, Korea. In RCF with two to six years old plants, soil pH and exchangeable $Ca^{2+}$ and $Mg^{2+}$ contents were higher at the leaf-emergence time, but EC, available phosphorus content, CEC, and total nitrogen content were higher at the harvesting time; especially at the harvesting time, the content of available phosphorus in the RCF with 3~6 years old plants were at least three times higher than in the RCF with 2 years old plants. Water-soluble anions ($Cl^-$, ${NO_3}^-$, ${PO_4}^{2-}$, and ${SO_4}^{2-}$) in the RCF were also measured. The contents of ${NO_3}^-$ and ${SO_4}^{2-}$ were always higher in the RCF with older plants than in the RCF with younger plants, which were not affected by sampling time and sampling locations (rhizosphere and non-rhizosphere sites). However, soils collected from non-rhizosphere at the leaf-emergence time contained higher ${PO_4}^{2-}$ content, but $Cl^-$ content was higher in the soils collected from rhizosphere at the harvesting time. In general, soils in the RCFs contained excess amounts of inorganic nutrients such as available phosphorus and exchangeable $K^+$. Thus, optimal levels of soil properties for Korean raspberry cultivation should be reconsidered.

• Journal of Environmental Health Sciences
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• v.33 no.4
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• pp.283-292
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• 2007

Atmospheric concentrations of radon had been continuously observed in Seoul, Korea since December 1999, as a tracer for long-range transport of air pollutants from China continent to Korea. In order to study radon as a tracer of long-range transport, it is important to know information about the atmospheric distribution and variation of radon concentration and its time variation. Atmospheric radon concentration are measured with electrostatic radon monitor(ERM) at Hanyang University located in Eastern area of Seoul. Air sample is taken into a vessel of ERM, and alpha particles emitted by radon daughters $Po^{218}$ are detected with ZnS(Ag) scintillation counter. Hourly mean concentrations and hourly alpha counts are recorded automatically. The major results obtained from time series observation of atmospheric radon were as follows : (1) The mean of airborne radon concentration in Seoul was found to be $7.62{\pm}4.11\;Bq/m^3$ during December $1999{\sim}January$ 2002. (2) The hourly variation of radon concentrations showed the highest in 8:00AM ($8.66{\pm}4.22\;Bq/m^3$) and the lowest in 3:00AM ($6.62{\pm}3.70\;Bq/m^3$) and 5:00AM ($6.62{\pm}3.39\;Bq/m^3$). (3) the seasonal variation of radon concentrations showed higher during winter-to-fall and lower during summer-to-spring. (4) Correlation between airborne radon concentration and the meteorological factors were -0.21 for temperature, 0.09 for humidity, -0.20 for wind speed, and 0.04 for pressure. (5) The mean difference of airborne radon concentration between Asian dust ($5.36{\pm}1.28\;Bq/m^3$) and non-Asian dust ($4.95{\pm}1.49\;Bq/m^3$) phenomenon was significant (p=0.08). We could identify time series distribution of radon concentration related meteorological factors. In addition, radon can be considered a good natural tracer of vertical dispersion and long-range transport.

• Journal of environmental and Sanitary engineering
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• v.11 no.3
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• pp.79-84
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• 1996

In order to determine the content of heavy metal in common salts, 35 bay salt samples, 7 refined salt samples, 7 fine salt samples, 5 bake salt samples and 5 bamboo bake salt samples were collected from old market in major cities. Heating bay salt 35 samples, it made heating bay salt of $500^{\circ}C$, /TEX>(34 samples), heating bay salt of $1000^{\circ}C$(35 samples). These were analysed for contents of lead(Pb), cadmium(Cd), iron(Fe) and zinc(Zn) by atomic absorption spectrophotometer. The results were as follows : Mean content of lead in bay salts was $0.124{\pm}0.035ppm$ refined salt was $0.130{\pm}0.019ppm$, fine salt was $0.073{\pm}0.036ppm$ bake salt was $0.097{\pm}0.023ppm$, bamboo bake salt was $0.117{\pm}0.020ppm$, heating bay salt was $0.063{\pm} 0.021ppm$ in $500^{\circ}C$, heating bay salt was $0.063{\pm}0.039ppm$ in $1000^{\circ}C$. And bay salt refined salt bamboo bake salt were not significant one another. Mean content of cadmium in bay salts was $0.031{\pm}0.008ppm$ refined salt was $0.032{\pm}0.003ppm$, fine salt was $0.037{\pm}0.005ppm$, bake salt was $0.169{\pm}0.117ppm$ bamboo bake salt was $0.079{\pm}0.052ppm$, heating bay salt of $500^{\circ}C$ was $0.030{\pm}0.029ppm$ heating bay salt of $1000^{\circ}C$ was $0.017{\pm}0.013ppm$. And bay salt refined salt, fine salt were not significant one another. Mean content of iron in bay salts was $1.025{\pm}0, 634ppm$, refined salt was $0.359{\pm}0.163ppm$ fine salt was $0.267{\pm}0.068ppm$, bake salt was $2.929{\pm}1.963ppm$, bamboo bake salt was $5.378{\pm}3.676ppm$, heating bay salt of $500^{\circ}C$ was $0.847{\pm}0.315ppm$ heating bay salt of $1000^{\circ}C$ was $0.991{\pm}0.868ppm$. And bay salt refined salt, fine salt, bake salt, bamboo bake salt were significant one another(p<0, 01). Mean content of zinc in bay salts was $0.253{\pm}0.154ppm$, refined salt was $0.263{\pm}0.091ppm$ fine salt was $0.187{\pm}0.015ppm$, bake salt was $0.166{\pm}0.034ppm$, bamboo bake salt was $0.282{\pm}0.064ppm$, heating bay salt of $500^{\circ}C$ was $0.253{\pm}0.085ppm$, heating bay salt of $1000^{\circ} C$ was $0.242{\pm}0.179ppm$. And bay salt refined salt fine salt, bake salt, bamboo bake salt were not significant one another.

• Korean Journal of Community Nutrition
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• v.19 no.2
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• pp.142-162
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• 2014

Objectives: To evaluate the critical environmental factors on healthy-aging of Korean people, we investigated the significant factors influencing health status of septuagenarians living in rural area of Jeonla province, known to be one of the representative longevity regions in Korea. Methods: We divided subjects into healthy group (36M/25F) or poor-health group (26M/73F) based on self-reported health status, body mass index, a number of prescription, and blood test data. General characteristics, physical measurements, lifestyle, dietary behavior and nutrient intake, physical health and mental health data were statistically compared between the two groups. Results: Average age was not different between healthy group and poor-health group in men and women, respectively. In men, significantly favorable factors to health were observed to be higher education, regular exercise, higher grip strength and walking function, body mass index (${\geq}18.5kg/m^2$), moderate frequency of drinking and eating-out, non-smoking, normal red blood cell (RBC) count, higher serum dehydroepiandrosterone-sulfate (DHEAS) level, good digestive function and appetite, normal hearing function, regular meals, adequate vegetable and fruit intake, diverse food intake, adequate energy and nutrients (protein, vitamin $B_1$, $B_6$, C and E, folate, niacin, P, Zn and K) intake, higher mini-nutrient status assessment (MNA) score and low level of depression. On the other hand, in women, those were literacy, living arrangement, moderate frequency of drinking, healthy teeth, higher grip strength and walking function, bone mineral density, normal RBC and white blood cell (WBC) count, higher DHEAS concentration, higher MNA score, normal cognition and memory function, having snack and adequate fruit intake. Conclusions: These results could be useful to plan effective strategies to increase health-life expectancy of Korean old people living in rural areas.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.231-237
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• 1999

It is very distinctive that sigumjang meju was produced with smoking after molding. Every shapes of traditional sigumjang meju gathered from Kyeongsangbukdo were doughnut types. Fermentation time were $60{\sim}90$ days. Aerobic bacteria were $6.8{\times}10^7\;cfu/g$, and anaerobic bacteria, yeasts, molds count $3.2{\times}10^6\;cfu/g,\;1.0{\times}10^6\;cfu/g\;and\;4.0{\times}10^6\;cfu/g$, respectively. Analysis showed: moisture content, $10.5{\pm}2.6%$; fat content, $2.9{\pm}1.1%$; protein content, $8.3{\pm}0.7%$; ash content, $3.8{\pm}0.7%$; pH, $6.0{\pm}0.5$; L-value, $54.5{\pm}4.7$; a-value, $+3.3{\pm}0.7$; and b-value, $+10.7{\pm}2.0$. K content was the most in quantity among the minerals in sigumjang meju. Maltose was most abundant component among the tested sugars followed by mannitol. Total content of amino acid was $1524.9{\pm}1295.3\;mg%$. Proline was the most abundant component among the amino acids. The ratio of essential amino acid was $30.0{\pm}12.9%$. The principal fatty acids were 18:2, 18:1 and 16:0. Saturated fatty acid and mono unsaturated fatty acid were $23.2{\pm}1.9%\;and\;23.5{\pm}5.2%$, respectively. The PUFA/SFA was $2.3{\pm,}0.3$ which higher than 1.