• Journal of the Korean earth science society
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• v.37 no.7
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• pp.434-447
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• 2016

This study analyzed mass concentrations of PM10 and PM2.5, as measured at Tae-ahn and Gang-nae, Cheongju in central Korea over the period from 2011 to 2015. Higher mass concentrations of PM10, with the exception of dustfall cases during the period of winter and spring, reflected the influence of a prevailing westerly airflow, while the level of PM10 stayed at a low level in summer, reflecting the influence of North Pacific air mass and frequent rainfall. Accordingly, cases where a daily PM10 average of $81{\mu}gm^{-3}$ or over (exceeding the status of fine dust particles being 'a little bit bad') were often observed during the period of winter and spring, with more cases occurring in parts of Tae-ahn that are located close to the sources of pollutant emission in eastern China. Dustfall usually originated from dust storms made up of particles $2.5{\mu}m$ or over in diameter. However, anthropogenic haze displayed a high composition ratio of particulate less than $2.5{\mu}m$ in diameter. Accordingly, brightness temperature difference (BTD) values from the Communication, Ocean and Meteorological Satellite (COMS) were $-0.5^{\circ}K$ or over in haze with fine particulate. PM10 mass concentrations and NOAA 19 satellite BTD for haze cases were analyzed. Though PM10 mass concentrations were found to be lower than $200{\mu}g\;m^{-3}$, the mass concentration ratio of PM2.5/PM10 was measured as higher than 0.4 and BTD was found to be distributed in the range from -0.3 to $0.5^{\circ}K$. However, the BTD of dustfall cases exceeding $190{\mu}g\;m^{-3}$, were found to be less than 0.4 and BTD was found to be distributed in the range less than $-0.7^{\circ}K$. The result of applying BTD threshold values of the large-scale transport of haze proved to fall into line with the range over which aerosols of MODIS AOD and OMI AI were distributed.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.554-563
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• 2006

Numerous epidemiological studies have shown stronger associations between $PM_{2.5}$ and both mortality and morbidity than $PM_{10}$. The association of $PM_{2.5}$ with respiratory mortality was examined in Seoul, during the period of $1996{\sim}2002$. Because $PM_{2.5}$ data were available for only 10% of this time period, a prediction regression model was developed to estimate $PM_{2.5}$ concentration. Death count due to respiratory-related diseases(total respiratory mortality; ICD-10, J00-J98) and death counts(cause-specific mortality) due to pneumonia(ICD-10, J12-J18), COPD(ICD-10, J40-J44) and asthma(ICD-10, J45-J46) were considered in this study. Averaged daily mortality was 5.6 for total respiratory mortality and 1.1 to 1.6 for cause-specific mortality. Generalized additive Poisson models controlling for confounders were used to evaluate the acute effects of particle exposures on total respiratory mortality and cause-specific mortality. An IQR increase in 5-day moving average of $PM_{2.5}(22.6{\mu}g/m^3)$ was associated with an 8.2%(95% CI: 4.5 to 12.1%) increase in total respiratory mortality The association of $PM_{2.5}$ was stronger for the elderly ($\geq$65 years old, 10.1%, 95% CI: 5.8 to 14.5%) and for males(8.9%, 95% CI: 2.1 to 11.3%). A $10{\mu}g/m^3$ increase in 5-day moving average of $PM_{2.5}$ was strongly associated with total respiratory mortality in winter(9.5%, 95% CI: 6.6 to 12.4%), followed by spring(3.1%, 95% CI: -1.2 to 7.5%), which was a different pattern with the finding in North American cities. However, our results are generally consistent with those observed in recent epidemiological studies, and suggest that $PM_{2.5}$ has a stronger effect on respiratory mortality in Seoul.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.4
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• pp.342-350
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• 2017

We report mass concentration and size fraction of TPM, $PM_{10}$ and $PM_{2.5}$ according to Korea standard test method (ES 01301.1 and ES 01317.1) and ISO 23210 methods. Particulate matters were sampled in large stationary emission sources such as a coal power plant and B-C oil refinery. The Korea standard test method PM mass concentrations showed 3~3.5 times larger than the cascade impactor method. On the other hand, the size fraction results showed less than 5% difference (i.e. $PM_{2.5}/PM_{10}$) between two methods. Moreover, the correlation coefficient ($r^2$) is 0.84 between TPM results of the Korea standard test method and CleanSYS. These results suggested not only improvement of current test criteria in terms of technical and theoretical aspects. Further, additional measurements are required in various large stationary sources to compare current field data.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.339-343
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• 1996

The effect of ginseng on the reactivity of penile corpus cavernosal smooth muscle strips of rabbits was investigated to support the clinical application of ginseng for the treatment of erectile dysfunction. New Zealand white rabbits were randomly divided into two groups, normal diet group (n=9) and ginseng saponin diet group (n=5). Then, each group was fed normal diet and Korean red ginseng saponin diet (50 mg/kg/day) for 10 weeks. We measured concentration dependent relaxation of corporal smooth muscle to acetylcholine (10-8 M to 10-4M) in organ chamber. The degree of relaxation was expressed as percentage of maximal relaxation obtained by papaverine (10-4M). Dose dependent relaxation of corpus cavernosal smooth muscle to acetylcholine, at the concentration of 10-8 M to 10-4M by half log increment, was 4.06$\pm$0.00, 4.30$\pm$1.30, 5.32$\pm$0.68, 11.64$\pm$1.74, 16.24$\pm$1.61, 23.33$\pm$ 2.29, 26.45$\pm$2.25, 30.43$\pm$2.40 and 33.41 $\pm$2.48 (%), respectively in normal diet group and 9. 83$\pm$4.15, 20.60$\pm$4.62, 24.1815.12, 35.75$\pm$5.71, 43.35$\pm$6.11, 51.30$\pm$6.22, 56.33$\pm$6.22, 54.30$\pm$4.17 and 51.98$\pm$3.92 (Vc), respectively in ginseng group. These data suggest that ginseng enhances ondothelium-dependent acetylcholine-induced relaxation of penile corpus cal.ernosal smooth muscle in rabbits.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.5
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• pp.515-520
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• 2017

$PM_{2.5}$ concentrations were measured using a cyclone, impactor (the U.S. Environmental Protection Agency well impactor ninety-six, WINS) and optical particle counter (OPC) at a campus site located in Yongin for the period August 2014 through March 2017. The concentrations from cyclone (Y) were generally higher than those from impactor(X); the best-fit line was Y=1.22X+5.64. The ratios of $PM_{2.5}/PM_{10}$ ranged from 0.61 to 0.66 when $PM_{2.5}$ concentrations from cyclones in selected studies were converted into those from impactors using a regression equation in this study. The slope of the best-fit line between OPC and impactor was close to 1 at 0.95, while that between OPC and cyclone was 0.72. After sampling, the flow rate in the low-volume air sampler with cyclone decreased by 3% on average, which did not have a significant effect on measured concentrations.

• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.16-24
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• 2024

Background: Indoor PM_2.5 concentrations in residential houses can be affected by various factors depending on the season. This is because not only do the climate characteristics depend on the season, but the activity patterns of occupants are also different. Objectives: The purpose of this study is to compare factors affecting indoor PM_2.5 concentrations in apartments and detached houses in Daegu according to seasonal changes. Methods: This study included 20 households in Daegu, South Korea. The study was conducted during the summer (from July 10 to August 10, 2023) and the autumn (from September 11 to October 9, 2023). A sensor-based instrument for PM_2.5 levels was installed in the living room of each residence, and measurements were taken continuously for 24 hours at intervals of one minute during the measurement period. Based on the air quality monitoring system data in Daegu, outdoor PM_2.5 concentrations were estimated using ordinary kriging (OK) in Python. In addition, the indoor activities of the occupants were investigated using a time-activity pattern diary. The affecting factors of indoor PM_2.5 concentration were analyzed using multiple regression analysis. Results: Indoor and outdoor PM_2.5 concentrations of the residences during summer were 15.27±11.09 ㎍/m³ and 11.52±7.56 ㎍/m³, respectively. Indoor and outdoor PM_2.5 concentrations during autumn were 13.82±9.61 ㎍/m³ and 9.57±5.50 ㎍/m³, respectively. The PM_2.5 concentrations were higher in summer compared to autumn both indoors and outdoors. The primary factor affecting indoor PM_2.5 concentration in summer was occupant activity. On the other hand, during the autumn season, the primary affecting factor was outdoor PM_2.5 concentration. Conclusions: Indoor PM_2.5 concentration in residential houses is affected by occupant activity such as the inflow of outdoor PM_2.5 concentration, cooking, and cleaning, as found in previous studies. However, it was revealed that there were differences depending on the season.

• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.17-20
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• 2000

Effect of predation of starfish Asterias amurensis and Asterina pectinifera under different water temperature in the recirculating seawater vessel was conducted at the invertebrate culture laboratory of Yosu National University from February 1 to February 25, 2000. The highest activity of Asterias amurensis and Asterina pectinifera according to water temperature was obtained at 14$\^{C}$ and 22$\^{C}$. The average individual numbers of Anadara broughtonii predated by Asterias amurensis and Asterina pectinifera were 2.20 and 1.60 at 6$\^{C}$ , 3.60 and 2.00 at 10$\^{C}$, 7.20 and 2.50 at 14$\^{C}$, 3.40 and 6.80 at 22$\^{C}$, 0.80 and 3.90 at 26$\^{C}$, respectively.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.144-148
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• 1998

Soil microorganisms including bacteria, fungi, and actinomycetes were seasonally isolated at depths (0.5~2, $10{\pm}1$, $50{\pm}1cm$) of field. The frequency of microbial isolates was employed for the determination of microbial population (CFU/g dry soil) and distribution ratio (%) in soil. Both bacteria (24-fold) and actinomycetes (7-fold) exhibited the biggest change at the depth of $50{\pm}1cm$, whereas fungi showed the maximum (13-fold) at $10{\pm}1cm$. On the whole, the bacterial population was high in spring soil, fungi in winter, and actinomycetes in autumn. Soil microorganisms also exhibited the seasonal variation on their distribution ratio (%). The maximum distribution ratio (85.7%) of bacteria was observed at the depth of $50{\pm}1cm$ in spring, whereas bacteria showed the minimum (35.2%) at the depth of $10{\pm}1cm$ in spring. The maximum distribution ratio (23.0%) of fungi was found at the depth of $50{\pm}1cm$ in spring, whereas its minimum (0.5%) at the depth of $10{\pm}1cm$ in spring. Actinomycetes exhibited the maximum distribution ratio (45.2%) at the depth of $10{\pm}1cm$ in spring, whereas its minimum (12.2%) was showed at the depth of $50{\pm}1cm$ in spring.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.6
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• pp.682-692
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• 2008

Fine particles ($PM_{2.5}$) were collected and analyzed from November 2005 through August 2007 in Chuncheon, Korea to investigate the characteristics of $PM_{2.5}$ and its ionic constituents. The average $PM_{2.5}$ concentration during the study period was $39{\mu}g/m^3$, which is almost two times higher than the annual US NAAQS $PM_{2.5}$ standard of $15{\mu}g/m^3$. $PM_{2.5}$ concentrations were higher in spring and winter than in summer and fall. During spring, Asian Dust events dramatically enhanced $PM_{2.5}$ concentrations, and long-range transport of $PM_{2.5}$ emitted in industrial area of China often occurred during winter based on trajectory analysis. Contribution of $PM_{2.5}$ to $PM_{10}$ concentrations ranged from $72{\mu}g/m^3$ during Asian Dust events to $457{\mu}g/m^3$, indicating that a large portion of $PM_{2.5{\sim}10}$ was transported from China during Asian Dust events. Among the major ionic constituents ${SO_4}^{2-}$ showed the highest concentration, followed by ${NH_4}^+$, ${NO_3}^-$ and ${NO_2}^-$. Chuncheon appeared to be ${NH_4}^+$ rich environment, indicating that $(NH_4)_{2}SO_4$ and ${NH_4}{NO_3}$ were the predominant forms of ${NO_3}^-$ and ${SO_4}^2$ in $PM_{2.5}$. Haze has frequently occurred in Chuncheon since So-Yang dam was constructed in 1973. Haze events were observed on 23 days during sampling period, and the average $PM_{2.5}$ concentration was approximately 1.6 times higher during haze events than during non-haze events. This result suggests that haze enhances the secondary aerosol formation because the aerosol spontaneously absorbs water to form a saturated salt solution, deriving a significant increase in the mass of the particle.

• Tuberculosis and Respiratory Diseases
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• v.49 no.5
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• pp.568-575
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• 2000

Background : Cytokines are chemical mediators that control and modulate many inflammatory processes. They work in different fashions in a variety of diseases. Discriminating between malignant effusion, tuberculous effusion, and parapneumonic effusion are crucial from the clinical view-point in Korea. In the current study, interferon-gamma (IFN-${\gamma}$), soluble interleukin-2 receptor (IL-2R), interleukin-6 (IL-6) and interleukin-10 (IL-10) were measured for this purpose. Methods : Pleural fluids from patients with malignant disease, tuberculosis, parapneumonic effusion and lung empysema were collected and gauged using commercial ELISA kits. Results : 34 patients were enrolled in this study. Among these 15 cases were malignant effusions, 12 were tuberculosis pleurisy and 7 were parapneumonic effusion and lung empyema. The levels of cytokines measured in this study were as follows, in order of frequency, malignant effusion, tuberculous effusion, parapneumonic effusion and lung empyema. The levels of INF-${\gamma}$ were higher in tuberculous effusion than in malignant or parapneumonic effusion ($295.5{\pm}585.5$ vs. $16.7{\pm}50$ vs. $10.0{\pm}0$ pg/ml, p>0.05). The levels of IL-2R were higher in tuberculous effusion than in malignant or parapneumoruc effusion ($7423.5{\pm}3752.8$ vs. $3247.4{\pm}1713.3$ vs. $3790.2{\pm}3201.1$ pg/ml, p<0.05). No significant differences were found in the levels of IL-6 between the groups ($600{\pm}12.8$ pg/ml in malignant effusion, $556.4{\pm}161.7$ pg/ml in tuberculous effusion, $514.4{\pm}224.8$ pg/ml in parapneumoruc effusion). IL-10 levels were higher in parapneumoruc effusion than in malignant or tuberculous effusions ($98.4{\pm}141.7$ vs. $28.2{\pm}55.5$ vs. $11.3{\pm}11.7$ pg/ml, p<0.05). Conclusion : These results suggest that the measurement of IL-2R levels in pleural fluids may be a useful means of differentiating between tuberculous effusion and pleural effusions of other origins, and that the measurement of IL-10 levels in pleural fluids may be useful to differentiate between parapneumonic effusion and pleural effusions of other origins.