• Journal of the Korean Society of Food Culture
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• v.17 no.1
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• pp.64-69
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• 2002

The effects of the Rhynchosia nulubilis extracts on serum lipid concentrations were evaluated in rats. Forty-two male Sprague-Dawley rats weighing $100{\pm}10g$ were divided into six groups and fed high fat and high cholesterol diets for four weeks. Experimental groups were administered with following diets; basal fat diet(control) and basal and high fat diets with 1% cholesterol and Rhynchosia nulubilis extract(40mg/kg, 400mg/kg and 4000mg/kg). The concentrations of serum triglyceride in rats fed the Rhynchosis mulubilis extract, high fat, 1% cholesterol, and RN-HFC(-40, -400, -4000mg/kg) groups were lower than those in other groups. The concentrations of total cholesterol in the RN-HFC (-40, -400, -4000mg/kg) groups were lower than those in fat diet groups. The concentrations of HDL-cholesterol in serum of the RN-HFC(-40, -400, 4000mg/kg) groups were significantly higer than those of other groups. The levels of LDL-cholesterol in serum of the RN-HFC(-40, -400, -4000mg/kg) groups were tended to be lower than those of other groups. These results suggest that Rhynchosia nulubilis extract may reduce elevated levels of serum lipid concentrations in rats fed high fat diets.

• Applied Microscopy
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• v.23 no.1
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• pp.77-90
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• 1993

The mechanism by which blastocysts implant to uterine endometrium has not been clearly understood. In the present study, the following question was investigated: how are hormonal levels changed and how is uterine endometrium morphologically changed? Results obtained are as follows: Concentrations of serum estradiol and progesterone were significantly increased on day 4 and 5 of pregnancy. Uterine concentrations of PGE and $PGE_{2a}$ were sharply increased on day 1 and maintained similar concentrations thereafter, reaching the maximum on day 5. Both prostaglandins (PGs) concentrations were gradually decreased thereafter. Furthermore, concentrations of PGs in implant sites were greater than those in non-implant sites. PBR (pontamine blue reaction) in uterine endometrium was positive on day 6 of pregnancy, indicating that vascular permeability was increased. Edema and changes in structure of cell components were pronounced in stroma where PBR was developed. Moreover, these were more prominent in implant sites than non-implant sites. These results suggest that uterine PGs as well as steroid hormones increase during implantation in rats and these hormones might be involved in the process of implantation by modulating vascular permeability and the fine structures of uterine endometrial cells.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.5
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• pp.561-568
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• 2003

Surface ozone concentrations are highly sensitive to meteorological variability. Therefore, in order to reveal the long-term changes in ozone due to the changes in precursor emissions, we need to remove the effects of meteorological fluctuations on the annual distribution of surface ozone. In this paper, the meteorologically adjusted trends of daily maximum surface ozone concentrations in two major Korean cities (Seoul and Busan) are investigated based on ozone data from 11 (Seoul) and 6 (Busan) sites over the period 1992 ∼ 2000. The original time series consisting of the logarithm of daily maximum ozone concentrations are splitted into long-term, seasonal and short-term component using Kolmogorov-Zurbenko (KZ) filter. Meteorological effects are removed from filtered ozone series using multiple linear regression based on meteorologcial variables. The long-term evolution of ozone forming capability due to changes in precursor emission can be obtained applying the KZ filter to the residuals of the regression. The results indicated that meteorologically adjusted long-term daily maximum ozone concentrations had a significant upward trend (Seoul: ＋ 3.02% yr$^{-1}$ , Busan: ＋ 3.45% yr$^{-1}$ ). These changes of meteorologically adjusted ozone concentrations represent the effects of changing background ozone concentrations as well as the more localized changes in emissions.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.4
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• pp.75-85
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• 2005

A study was performed to examine the effects of reclaimed-water irrigation on microorganism con-centration in ponded-water of paddy rice plots. Several treatments were used and each one was triplicated to evaluate the change of indicator microorganisms (total coliforms (TC), fecal coliforms FC), and E. coli) concentrations in 2003 and 2004 growing seasons. Their concentrations increased significantly right after irrigation, but decreased about $45\%$ in 24 hours. It implies that agricultural activities such as plowing and fertilizing should be practiced one or two days after irrigation considering health-risks. Treatments with UV-disinfected water irrigation demonstrated significantly lower concentrations than others including control plots where natural surface water was irrigated. The monitoring results from actual paddy rice fields and experimental paddy plots showed that concentrations of indicator microorganisms ranged from $10^2\;to\;10^5$ MPN/100mL. A comprehensive assessment of existing agricultural practices and a thorough monitoring in the field as well as treatment-plots are recommended to make more realistic national guidelines more applicable. UV-disinfected water irrigation reduced microorganism concentrations in paddy fields down to below the concentration of conventional paddy rice culture, and is thought to be an effective and feasible measure fur agricultural reuse of secondary effluent.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.5
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• pp.494-503
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• 2011

Fine particles ($PM_{2.5}$) were collected and analyzed from December 2005 through December 2009 in Chuncheon, Korea to investigate the long-term trend of $PM_{2.5}$ concentrations. Also $PM_{10}$ concentrations were collected from Environmental Monitoring System operated by Ministry of Environment. Average concentrations of $PM_{2.5}$ and $PM_{10}$ were 30.5 and 58.2 ${\mu}g/m^3$, respectively. Both $PM_{2.5}$ and $PM_{10}$ were significantly affected by meteorological factors including wind speed, wind direction and precipitation. They generally decreased as wind speed increased (p=0.000), and increased when there was a prevailing westerly wind. Low concentrations of $PM_{2.5}$ were observed during rainy days while high concentrations were shown when fog, mist and/or haze occurred.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.2
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• pp.11-17
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• 1987

Atmospheric particulate matter (A.P.M.) was collected on quartz fiber filters from March 1985 to February 1986 at Chung-Ang University according to particle size using Andersen high-volume air smapler, and benzo (a) pyrene concentration in these particulates were analyzed by high performance liquid chromatography. The annual arithmetic mean concentration of A.P.M. was 115.50$\mug/m^3$. The annual arithmetic mean concentrations of coarse particles and fine particles in A.P.M. were 52.54$\mum/m^3$ and 62.96$\mum/m^3$ respectively. THe annual arithmetic mean concentration of benzo(a)pyrene in A.P.M. was 1.44$ng/m^3$. THe annual arithmetic mean concentrations of benzo(a)pyrene in coarse particles and fine particles were 0.05 $ng/m^3$ and 1.39 $ng/m^3$ respectively. Thus, the concentration of benzo(a)pyrene showed maldistribution of 96.53% in fine particle. A.P.M. showed wide fluctuation according to the season. The concentration of A.P.M. was lowest in summer and high in spring and winter. Coarse and fine particle concentrations in A.P.M. were highest in spring and winter, respectively. The concentrations of benzo(a)pyrene was highest in winter and lowest in summer. The concentrations of benzo(a)pyrene in fine and coarse particles were highest in winter and spring, respectively.

• Asian Journal of Atmospheric Environment
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• v.4 no.1
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• pp.9-19
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• 2010

The size distribution of airborne particulate matter (PM) and the concentrations of associated metallic elements were investigated in a busy urban region of a typical Korean industrial city. The PM concentrations measured during the spring, except for those in the size range of 1.1 to 2.1 ${\mu}m$, were slightly higher than the PM concentrations in the summer. Coarse particles contributed greatly to the variation in PM concentrations in the spring, while fine and submicron particles contributed largely to the variation in PM concentrations in the summer. The difference in size modes of the PM concentrations between spring and summer may be explained by the Asian dust effect and its accompanying wind direction and speed. Extremely high enrichment factors (EFs) values (6,971 to 60,966) for all of the size distributions in PM were identified for cadmium (Cd). High EFs values (12 to 907) were also identified for other heavy metals including Cr, Cu, Ni, Pb, Zn and Mn. Low EF values (0.29 to 8.61) were identified for Ca, K, Mg and Na. These results support the common hypothesis that most heavy metals in ambient PM have anthropogenic sources and most light metals have crustal sources. The results of principal components analyses and cluster analyses for heavy metals indicate that the principal sources of PM and metals were emissions from non-ferrous metal smelters, oil combustion, incinerators, vehicular traffic and road dust.

• Journal of Environmental Health Sciences
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• v.31 no.1
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• pp.94-98
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• 2005

This study was carried out to provide radon concentration and exposure in building. The average radon concentrations of building was measured 1.37 pCi/L in basement, 0.95 pCi/L in 1st layer, 0.74 pCi/L in 2nd layer, 0.56 pCi/L in 3rd layer, and 0.4 pCi/L in 4th layer, respectively. The average radon concentration of basement was measured the higher than any other stairs. Daily average distribution of radon concentrations in building shown that radon concentrations measured in morning at 8hr was the highest value. Monthly average distribution of radon concentrations shown 0.28 ${\pm}$ 0.17 pCi/L in April and 0.82 pCi/L in December that was the highest value. The average concentrations of radon was measured 0.38pCi/L in spring. 0.44 pCi/L in summer, 0.53 pCi/L in autumn, and 0.67 pCi/L in winter, respectively. This result shown that the average concentrations of radon in winter was the higher than any other seasons. That reasons was supposed that effect of number of exchanges and using air conditions was the higher in summer than winter.

• Journal of Environmental Science International
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• v.11 no.8
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• pp.801-810
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• 2002

The current paper describes the indoor/outdoor air quality in school environments through analyses of the heavy metal concentrations using Inductive Coupled Plasma(ICP). School environments in a heavy traffic area, two industrial areas, quasi-industrial area, and residential area were evaluated. The results were as follows: (1) The locations with the highest indoor and outdoor concentrations of heavy metals were the industrial areas followed by the heavy traffic area, residential area, and quasi-industrial area in a descending order of magnitude. Plus, the indoor heavy metal concentrations were higher then the outdoor ones. (2) The main heavy metal components were Zn, Al and Ca. Higher concentration levels were found indoors than outdoors. The heavy metal concentrations were also higher in the classrooms than in the corridor or outdoors. (3) The total heavy metal concentrations in the studied areas were highly dependent on the weather elements. including the relative humidity, mixing ratio, and wet-bulb depression. Accordingly, special ventilation systems are recommended to reduce air pollution in school environments.

• Child Health Nursing Research
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• v.26 no.1
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• pp.98-106
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• 2020

Purpose: This study utilized data from the Korean National Health and Nutrition Examination Survey (KNHANES) to explore differences in the timing of menarche in Korean girls according to blood heavy metal concentrations. Methods: This study performed a secondary analysis of cross-sectional data from the sixth KNHANES. Data from 179 female children and adolescents aged 10~18 were included in this study. The relationships of blood heavy metal concentrations (lead, mercury, and cadmium) with age of menarche were analyzed using complex sample multiple logistic regression. Results: In the participants of this study, the geometric mean values of blood lead, mercury, and cadmium concentrations were 1.15±0.04 ㎍/dL, 1.80±0.08 ㎍/L, and 0.30±0.03 ㎍/L, respectively. Mercury poisoning (>5 ㎍/L) was found in 1.5% of participants. Furthermore, significant relationships were found between blood lead and mercury concentrations and age at menarche (p for trend: p<.001 and p=.015, respectively). Conclusion: Through an analysis of national big data, this study found evidence that Korean girls showed a younger age at menarche in response to higher blood lead and mercury concentrations. To prevent and manage precocious puberty in Korean children and adolescents, a systematic policy that monitors both exposure to environmental hazards and blood heavy metal concentrations is needed.