본 연구에서는 아스팔트 바인더의 절대점도, 동점도, 침입도, 연화점, PG 고온등급을 이용하여 샌드아스팔트 흔합물의 고속 직접인장강도(DTS1), 저속 직접인장강도(DTS2), 간접인장강도(ITS), 회복탄성계수(MR), 강성지수(SI)를 추정하기 위한 연구를 수행하였다. 여러 가지 혼합물의 특성 중 DTS2가 가장 상관성이 높게 나타났으며 그 다음이 DTS1, ITS, SI, MR 순인 것으로 나타났다. 바인더 성질 중에는 PG 등급이 DTS2와 가장 높은 상관 관계를 보여 PG 고온등급이 높은 바인더를 사용하면 직접인장강도가 어느 정도 우수한 혼합물을 얻을 수 있음을 알 수 있었다. 하지만 각각의 물리적 성질만으로는 신뢰도가 낮아 종합적으로 여러 물성을 이용하여 상관성을 분석하였다. 그 결과 직접 및 간접인장강도는 결정계수가 0.99 이상인 모델을 얻을 수 있었다. 그리고 MR, SI 값의 추정치 모델도 R2이 0.91 및 0.93 이상이어서 상당한 신뢰성을 가지고 물성으로부터 역학적 특성을 추정할 수 있음을 보여준다.

Measurements on mass size distribution of roadside aerosols were obtained in downtown Jeju City from July 2018 to May 2020 using an 8-stage cascade impactor sampler and the compositions of aerosols were analyzed. The mass size distribution of total aerosols was bimodal with aerosols existing in both the fine and coarse modes. The mass size distributions of Na+, Mg2+, Ca2+, Cl-, NH4 + and SO4 2- were unimodal, whereas that of K+ was bimodal. For NO3 -, the size distribution in winter and spring was bimodal with the peaks in both fine and coarse modes, whereas for summer and autumn the distribution was unimodal with a peak in the coarse mode. NH4 + was found to co-exist with SO4 2- in the fine mode with an average molar ratio of [NH4 +]/[SO4 2-] equal to 2.05. Good correlation was observed between NO3 - and NH4 + in the fine mode particles in spring and winter. Based on the value of the marine enrichment factor for Cl-, Mg2+, K+, Ca2+ and SO4 2-, it may be inferred that a major part of the roadside aerosols in downtown Jeju City was largely contributed by terrigenous sources, although the influence of sea salt was normally present.

Jeju Special Self-Governing Province has implemented a self-governing environmental impact assessment system (Jeju-EIAS) in recognition of its autonomy. In this study, the institutional features of Jeju-EIAS were examined by analyzing the development projects whose consultation under Jeju-EIAS were completed from 1994 to 2019. The consultation procedure of Jeju-EIAS, such as the actual operation of Review Committee for Environmental Impact Assessment (EIA), the consent of the provincial council, and the regular follow-up activities for the implementation of EIA consultations, has been implemented differently from those of other metropolitan cities and provinces. Under Jeju-EIAS, types of development projects subject to consultation on EIA also take into account local conditions, and include the construction of aquarium basin and building. In addition, provisions concerning the scale of development projects is strengthened above the Korean Environmental Impact Assessment Act (EIA Act).

This study investigated the nitrate formation process, and mass closure of Particulate Matter (PM) were calculated over the urbanized area of Jeju Island. The data for eight water-soluble inorganic ions and nineteen elements in PM2.5 and PM10 were used. The results show that the nitrate concentration increased as excess ammonium increased in ammonium-rich samples. Furthermore, nitrate formation was not as important in ammonium-poor samples as it was in previous studies. According to the sum of the measured species, approximately 45~53% of gravimetric mass of PM remained unidentified. To calculate the mass closure for both PM2.5 and PM10, PM chemical components were categorized into secondary inorganic aerosol, crustal matter, sea salt, trace matter and unidentified matter. The results by the mass reconstruction of PM components show that the portion of unidentified matter was decreased from 52.7% to 44.0% in PM2.5 and from 45.1% to 29.1% in PM10, despite the exclusion of organic matter and elemental carbon.

To determine the size distributions of water-soluble inorganic ionic species (WSIS) in roadside aerosols, sampling experiments were carried out in the urban roadside area of Jeju City on August 2018 and January 2019 by using the eight-stage cascade impactor sampler. The mass of roadside aerosols were partitioned at 57% in fine fraction, 36-37% in coarse fraction, and 6-7% in giant fraction, regardless of summer and winter. The mass concentrations of WSIS except for Na+ and SO42- in roadside aerosols were higher in winter than in summer. The size distributions of Na+, Mg2+, Ca2+ and Cl- were characterized by bimodal types with coarse particle mode peaking around 3.3-4.7㎛ and 5.8-9.0㎛ . The size distributions of NO3 - and K+ shifted from a single fine mode peaking around 0.7-1.1㎛ in winter to bimodal and/or trimodal types with peaks around coarse mode in summer. SO4 2- and NH4 + showed a single fine mode peaking around 0.7-1.1㎛ . The MMAD of roadside aerosols was lower than that of Na+, Mg2+, Ca2+ and Cl-. Based on the marine enrichment factors and the ratio values of WSIS and the corresponding value for sea water, the composition of roadside aerosols in Jeju City may be practically affected by terrestrial sources rather than marine source.

Lung cancer, the most common malignant disease worldwide, is the predominant cause of cancer deaths, particularly amongst men. Therefore, various researchers have focused on the growth inhibitory effects of medicinal plants used in traditional Korean medicine. This study aimed to investigate the growth inhibitory effects of ethanol extracts of Rubiae radix, Inulae flos, Nelumbinis receptaculum, Astilbe radix, and Lagerstroemia flos on NCI-H1229 cells. Method and Results: The viability of NCI-H1229 cells was evaluated in vitro using an MTS assay. Treatment with the ethanol extracts of the selected medicinal plants at 500 ㎍/㎖ reduced NCI-H1229 cell viability and increased apoptotic cell death and caspase-3 activation. In addition, treatment with ethanol extracts of Inulae flos and Astilbe radix increases DNA fragmentation, as measured by the TUNEL assay. Conclusions: These results indicated that ethanol extracts of Rubiae radix, Inulae flos, Nelumbinis receptaculum, Astilbe radix, and Lagerstroemia flos exhibited growth inhibitory effects, inducing apoptotic cell death, DNA fragmentation and caspase-3 activation in NCI-H1229 cells. Therefore, these medicinal plant extracts may be used in the development of natural medicines to inhibit the growth of lung cancers. However, further study is needed to determine the active ingredients of the ethanol extracts from medicinal plants that are reposible for the inhibitory effect on lung cancer cell grwoth.

This study observed particulate matter (PM2.5 and PM10) in the downtown area of Jeju City, South Korea, to understand the chemical composition of particulates based on an analysis of the water-soluble ionic species contained in the particles. The mass fraction of the ionic species in the sampled PM10 and PM2.5 was 44.3% and 42.2%, respectively. In contrast, in Daegu City and Suwon City, the mass fraction of the ionic species in PM2.5 was higher than that in PM10. The chloride depletion percentage of PM10 and PM2.5 in Jeju City was higher than 61% and 66%, respectively. The contribution of sea-salt to the mass of PM10 (5.9%) and PM2.5 (2.6%) in Jeju City was similar to that in several coastal regions of South Korea. The mass ratio of Cl- to Na+ in the downtown area of Jeju City was comparable to that in some coastal regions, such as the Gosan Area of Jeju Island, Deokjeok Island, and Taean City. The mass fraction of sea-salt in PM10 and PM2.5 was very low, and the concentration of sodium and chloride ions in PM10 was not correlated with those in PM2.5 (R2 < 0.2), suggesting that the effects of sea-salt on the formation of particulate matter in Jeju City might be insignificant. The relationship between NH4 + and several anions such as SO4 2-, NO3 -, and Cl-, as well as the relationship between the measurement and calculation of ammonium ion concentration, suggested that sea-salts may not react with H2SO4, and (NH4)2SO4 may be a major secondary inorganic aerosol component of PM2.5 and PM10 in Jeju City.

From November 2013 to December 2016, ambient fine particulate matter (PM2.5) was sampled in the downtown area of Jeju City, South Korea, which has seen rapid urbanization. The atmospheric concentrations of elements were measured in the PM2.5 samples. This study focused on Cd, Cr, Cu, Mn, Ni, Pb, As, Sb, Sn, V, and Zn. The concentrations of Al, Na, K, Fe, Ca, Mg, Sr, and La were also obtained for reference. The objectives of this study were to examine the contributions of these elements to PM2.5 concentrations in downtown Jeju City, and to investigate the inter-element relationships and the elemental sources by using enrichment factors and principal components analysis (PCA). A composition analysis showed that the 19 elements constituted 6.65 % of the PM2.5 mass, and Na, K, Al, Fe, Ca, Mg, and Zn constituted 98 % of the total ion mass. Seasonal trend analysis for the sampling period indicated that the concentrations of the elements increased from November to April. However, no substantial seasonal variations were found in the concentrations of the elements. The composition ratios of some elements (Cu/Zn, Cu/Cd, Cu/Pb, V/Ni, and V/La) were found to be out of range when compared to the literature from other urban areas. The ratios between the elements and the PCA results showed that local contaminant sources in Jeju City rarely influence the composition of PM2.5. This suggests that the major sources of PM2.5 in Jeju City may include long-range transport of fine particulate matter produced in other areas.

Erectile dysfunction (ED), also known as impotence, is the inability to attain and sustain an erection firm enough to have sexual intercourse. Frequent ED may be a symptom of health problems including heart disease, obesity, alcoholism, stress, smoking, and depression, that need treatment. This study aimed to effect of complex extract (CPL) including Cornus officinalis on sexual function factor in the erectile dysfunction rat model. The erectile dysfuction rat model was induced by cimetidine (500 ㎎/㎏ in 5% ethanol, oral injection 2 weeks). Rats were oral administered with different concentration of CPL in rat erectile dysfunction model. As a results, sexual function factors (NO, cGMP) significantly improved in CPL treated groups (CPL-300, 600, 900 ㎎/㎏) compared to CON group. Serum testosterone was increased in a dose-dependent manner after CPL treatment. Furthermore, administrations of CPL restored lumen areas of the prostate in the erectile dysfunction rat model. These results indicated that CPL alleviated erectile dysfunction by increasing sexual function factor and testosterone in rat model. CPL could be used to natural treatement for erectile dysfunction. However, further study is required to identify active ingredient and its mechanism of erectile dysfunction.

Doxorubicin is a anti-cancer drugs that interferes with the growth and spread of cancer cells in human body. Doxorubicin is used to treat different types of cancers that affect the ovary, thyoid and lungs, but induced side effect such as nephrotoxicity and cardiotoxicity. Thus, we investigated that the effect of iridin on doxorubicin-induced necrosis in HK-2 cells, a human proximal tubule cell. To confirm effect of iridin on doxorubicin-induced necrosis, HK-2 cells are treated with 10 μM doxorubicin and 80 μM iridin. 80 μM iridin reduced 10 μM doxorubicin-induced necrosis, the mitochondrial over activation and caspase-3 activation. However, iridin reduces anti-cancer effect of doxorubicin such as PARP1 and caspase-3 activation, checkpoint proteins (CDK4 and CDK6) in NCI-H1129 cells (Human non-small cell lung cancer cell). In HCT-116 cells (Human colorectan cancer cell), iridin do not increased protein expression of CDK4 and CDK6 decreased by doxorubicin. Results indicate that treatment of iridin was diminished doxorubicin-induced necrosis in HK-2 cells. However, iridin was decreased anti-cancer effect of doxorubicin on NCI-H1229, but not HCT-116. Thus, further experiment are required to iridin treatment on various cancer cells and animal models because effect of iridin different cell type.

Background: Cisplatin is one of the most extensively used chemotherapeutic agents for the treatment of cancer, including bladder, and ovarian cancers. However, it has been shown to induce nephrotoxicity, despite being an outstanding anti-cancer drug. In this study, we investigated the protective effect of dopaol β-D-glucoside (dopaol) on cisplatin-induced nephrotoxicity. Methods and Results: To confirm the protective effect of dopaol on cisplatin-induced nephrotoxicity, HK-2 cells were treated with 20 μM cisplatin and 80 μM dopaol. Cisplatin increased apoptosis, caspase-3 activity and mitochondrial dysfunction; however pretreatment with 80 μM dopaol successfully attenuated apoptosis, caspase-3 activity and mitochondrial dysfunction. To evaluate the protective effect dopaol on cisplatin-induced nephrotoxicity in vivo, we used an animal model (balb/c mice, 20 ㎎/㎏, i.p. once/day for 3 day). The results were similar to those obtained using HK-2 cells; renal tubular damage and neutrophilia induced by cisplatin reduced following dopaol injection (10 ㎎/㎏, i.p. once/day for 3 day). Conclusions: These results indicate that dopaol treatment reduced cisplatin-induced nephrotoxicity in vitro and in vivo, and can be used to treat cisplatin-induced nephrotoxicity. However, further studies are required to determine the toxicity high dose dopaol and the signal pathways involved in its mechanism of action in animal models.

This study was carried out to elucidate the chemical compositions of water-soluble inorganic ions in PM10 and PM2.5 aerosols collected during summer and winter in downtown Jejusi city. The ratios of NO3 - to the total mass of ionic species in PM10 and PM2.5 aerosols largely increase in winter compared to summer, while SO4 2- ratios in both aerosols appear to follow the opposite trend. Moreover, concentrations of Na+, Mg2+, Ca2+ and Cl- in PM10 and PM2.5-10 aerosols are higher in winter than in summer. The nitrate concentrations in PM10 and PM2.5 aerosols increase with an identical increase in excess ammonium during winter, however, nitrate formation during summer is not important owing to ammonium-poor conditions.

Chemical properties of aerosols were investigated by analyzing the inorganic water-soluble content in PM2.5 collected in the downtown area of Jeju City in Jeju Island. Due to an increase in both the number of visiting tourists and the size of local population, the number of cars in this area is increasing, causing an increase in PM2.5. Eight PM2.5-bound major inorganic ions were analyzed during the summer and winter periods. The water-soluble inorganic component represents a significant fraction of PM2.5. In particular, secondary inorganic aerosols contribute 36.2% and 47.5% of PM2.5 mass in summer and winter, respectively. Nitrate concentrations increase for [NH4 +]/[SO4 2-]>1.5, and excess ammonium, which is necessary for ammonium nitrate formation, is linearly correlated with nitrate. These results are clearly observed during the winter because conditions are more conducive to the formation of ammonium nitrate. A significant negative correlation between Nitrogen Oxidation Ratio (NOR) and temperature was observed. The obtained results can be useful for a better understanding of the aerosol dynamics in the downtown area in Jeju City.

Background: Constipation is one of the most common functional gastrointestinal disorder. The present study examined the ability of water extract of fermented (FRC) and non-fermented (NFRC) roasted Cassia tora to improve intestinal function and reduce constipation in a rat constipation model.Methods and Results:Different concentration of FRC and NFRC were orally administered loperamide (5 ㎎/㎏; LOP) reduced the number, weight, and water content of feces, as well as intestinal transit motility. However, 24 h-(24 hour fermented roasted-Cassia tora) 300 ㎎/㎏ FRC administration increased the number, weight, and water concent of feces, compared to that seen in the LOP group, and also improve intestinal transit mitility and, the thickness of distal colon and mucous fluid.Conclusions:The results of the present study indicated that LOP-induced constipation was improved by treatment with FRC. Therefore FRC could be used to develop functional foods or natural medicine for constipation. However, further study is needed to clarify how fermentation improves the medicinal properties of roasted C. tora.

In this study, mass concentrations and chemical compositions of PM2.5, including water-soluble ions and elements were determined at the 1,100 m-highland of Mt. Hallasan in Jeju Island across four seasons from August 2013 to August 2014. The average mass concentration of PM2.5 was 12.5±8.41 /m3 with 45.8% of the contribution from eight water-soluble ionic species. Three ionic species (SO4 2-, NH4 +, and NO3 -) comprised 96.2% of the total concentration of ions contained in PM2.5 and were the dominant ions, accounting for 43.5% of the PM2.5 mass at Mt. Hallasan. On the basis of the mass concentration level, seasonal variation, enrichment factor, and relationship among elements, we can presume that Mg, K, Ca, Mn, Fe, Co, Sr, Ba, Nd, and Dy originated mainly from crust or soil and that V, Cr, Ni, Cu, Zn, As, Cd, and Pb were significantly enriched in PM2.5 owing to the effects of the anthropogenic emissions. These results and the local distribution of emission sources and topographic characteristics near this sampling site suggest that the compositions of PM2.5 collected at the 1100 m-highland of Mt. Hallasan were largely influenced by inflow from outside of Jeju Island.

Background: Sedum takesimense Nakai has been used as folk medicine in Korea. The present study aimed to determine the biological activity of S. takesimense by investigating the anti-inflammatory effects of S. takesimense water extract (SKLC) on the lipopolysaccharide-induced inflammatory response in RAW 264.7 cells. Methods and Results: Cytotoxicity of SKLC on RAW 264.7 cells was determinded by performing MTS assay was found to have no cytotoxic effect on RAW 264.7 cells at a concentration range of 62 - 500 ㎍/㎖. Further, pretreatment of SKLC inhibited lipopolysaccharide-induced nitric oxide (NO) production in a dose-dependent manner. To determined the inhibitory mechanisms of SKLC on inflammatory mediators, we assessed the inducible nitric oxide synthase (iNOS) and cyclooxygnease-2 (COX-2) pathways. The activities of these pathways were decreased in a dose-dependent manner by SKLC. The production of tumor necrosis factor- α (TNF-α), interleukin (IL)-1β‚ and IL-6 were also reduced. Conclusions: These results suggest that the down regulation of iNOS, COX-2, TNF-α, IL-1β‚ and IL-6 expression by SKLC are mediated by the down regulation of nuclear factor-κB (NF-κB) activity, a transcription factor necessary for pro-inflammatory mediators. This might be the mechanism underlying the anti-inflammatory effects of SKLC.

The ambient mass concentration and chemical composition of the PM2.5 were determined at the highland site with 1,100 m above sea level on Jeju Island from June 2013 to November 2014. Yearly averaged mass concentration of PM2.5 was 11.97±8.63 /m3. PM2.5 concentrations were highest during the spring, while they tended to be lowest during the summer. Eight water soluble ionic species attributed 45.5% to PM2.5 mass. SO4 2-, NO3 - and NH4 + were major ions, which occupied to 27.9%, 3.7% and 12.3%, respectively. The greatest contributors to total mass concentration of water-soluble ions contained in PM2.5 were sulfate, ammonium and nitrate. These three ions accounted for 96.6% in total ions mass concentration of PM2.5. We could infer that these three secondary ions exist mostly in the form of (NH4)2SO4 and NH4NO3. Ca2+ and Mg2+ had a good relationship and with r=0.9. The molar ratio of Mg2+/Ca2+ in this study was lower than the value observed in sea water and higher than that in soil dust, indicating that these two ions originated from other sources rather than ocean and soil dust in this study.

Dendrobium loddigesii (DL) is a valuable and versatile herbal medicine with the anecdotal claims of anti-oxidant and anti-inflammation. In the present study, we investigated the whitening effects of DL under various conditions with B16F10 melanoma cells. The DL extract inhibited melanin contents and tyrosinase activity in a dose-dependent manner, compared with untreated group. Treatment of the DL extract effectively suppressed the α-MSH-stimulated melanin formation, tyrosinase activity and dendrite outgrowth. Moreover, the α-MSH-induced mRNA expressions of tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2), microphthalmia-associated transcription factor (MITF) and protein expression of tyrosinase were significantly attenuated by DL treatment. These results indicate that DL may be a great cosmeceutical ingredient for its whitening effects.

The purpose of this study is to show the geographical distribution and the temporal variation of the emission amount of biogenic volatile organic compounds(BVOCs) emanated from forests at Jeju Island. The total emission amount of BVOCs calculated by using the CORINAIR Methodology is 3612 ton yr-1 at Jeju Island. More than half of BVOCs emissions is come from coniferous forest, and 45 per cent from broad leaved forest. The others is attributed to grassland. Of total emission of BVOCs, isoprene accounts for 28 per cent, monoterpene for 32 per cent, and other VOCs for about 40 percent, respectively. It can be shown that 3000~10000 kg yr-1 of BVOCs is emitted at the zone with dense forest from an altitude of 500 m to the top of Mt. Halla, and less than 1500 kg yr-1 at the zone an altitude of below 500 meters. The monoterpene emission is more than 1500 kg yr-1 due to the existence of a colony of Abies koreana at the place with more than 1500 meters and a community of Pinus thunbergii and Cryptomeria japonica at the elevation of 500~700 m. In the case of isoprene emission, there is 1500~3000 kg yr-1 at the zone of an elevation from 700 m to 1500 m due to dense broad leaved forest and very little of its emission at an elevation of more than 1500 meters because there is hardly broad leaved trees grown. In this study, emission of BVOCs according to the altitude above sea level is estimated under the situation of lack of the data for broad leaved tree. More detailed data and information for the distribution of broad leaved trees are needed in order to calculate more realistic BVOC emission.