This study investigated major constituents and anti-inflammatory effects of an ethanol extract of Platycodon grandiflorum leaves. Through HPLC analysis, chlorogenic acid and luteolin-7-O-glucoside were identified as predominant constituents in the ethanol extract. Their anti-inflammatory effects were evaluated using murine macrophage (RAW 264.7 cells) and human lung carcinoma cells (NCI-H292 & A549). The ethanol extract significantly (p<0.01) inhibited the production of nitrite, interleukin-6 (IL-6), and prostaglandin E2 (PGE2) induced by lipopolysaccharide (LPS) in RAW 264.7 cells. Furthermore, the ethanol extract suppressed the expression of cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS) proteins in RAW 264.7 cells stimulated with LPS. In NCI-H292 and A549 cells, treatment with the ethanol extract significantly (p<0.05) decreased levels of pro-inflammatory cytokines IL-6 and IL-8 induced by IL-1β. The phosphorylation of ERK rather than JNK in the mitogen-activated protein kinase signaling pathway was observed to be a more important mediator in the down-regulation of pro-inflammatory cytokines in NCI-H292 cells. These findings suggest that the ethanol extract of Platycodon grandiflorum leaves containing luteolin-7-O-glucoside exhibits promising anti-inflammatory properties.

기후변화 관점에서 수목의 이산화탄소 흡수·저장에 대한 관심이 높아지고 있으며, 도시 정주지 수목을 대상으로 한 탄소저장량 추정 모형의 개발에 대한 필요성도 증가하고 있다. 본 연구는 도시 지역에 조경수로 식재된 서양측백(Thuja occidentalis L.) 20본을 벌채한 후 수목 부위별 탄소 농도를 비교하고 탄소저장량 추정 상대생장식을 개발하였다. 수목 부위별 바이오매스는 흉고직경(DBH)의 증가와 강한 지수함수적 관계가 있었다. 수목 부위별 탄소 농도는 줄기 목질부가 51.7%로 가장 높은 값을 보였으며 뿌리는 42.9%로 가장 낮았다. 줄기 목질부 탄소 농도는 흉고직경과 양의 상관관계가 있었으나, 수피, 가지, 잎, 뿌리의 탄소 농도는 흉고직경과 상관관계가 나타나지 않았다. 흉고직경 또는 흉고직경 제곱과 수고(DBH2×H)를 독립변수로 하고 수목 부위별 탄소저장량을 종속변수로 하는 상대생장식의 결정계수(R2)는 잎(0.70~0.71)을 제외한 모든 부위에서 0.80~0.97로 나타났다. 본 연구 결과로부터 얻어진 수목 부위별 탄소저장량 추정 상대생장식은 도시 정주지에 식재된 서양측백의 탄소저장 량 및 흡수량의 추정에 활용이 가능할 것으로 사료된다.

Mangroves are distributed in intertidal zones of coastal environments or estuarine margins, playing a critical role in the global carbon cycle. However, understanding of the carbon cycle role of mangrove associates in the Republic of Korea is still limited. This research measured soil respiration and leaf gas exchange in three habitats of Hibiscus hamabo (Gimnyeong, Seongsan, and Wimi) and analyzed the impacts on sites and months. Soil respiration was measured once a month from June to October 2022 and leaf gas exchange was measured monthly from June to September 2022. Soil respiration in August (5.7±0.8 μmol CO2 m-2 s-1) was significantly higher than that in other months (p<0.001) and soil respiration increased as air temperature increased (p<0.001). In Seongsan, net photosynthesis in July (9.0±0.9 μmol m-2 s-1) was significantly higher than that in other months (p<0.001). Net photosynthesis increased as stomatal conductance and transpiration rate increased during the entire period (p<0.001). Furthermore, a weak positive linear relationship was observed between soil respiration and net photosynthesis (r2=0.12; p<0.01). The results indicated that soil respiration was influenced not only by air temperature and season but also by net photosynthesis. This study is expected to provide basic information on the carbon dynamics of mangrove associates.

The microstructure and mechanical properties of the heat-affected zone welded using the GTAW process on SDSS material used in offshore structures were analyzed. The chemical composition of the specimen material was analyzed using XRF. The microstructure of the heat-affected zone where the plate was welded was examined by SEM, and the ferrite volume fraction was assessed using the point count method of ASTM E562. A lot of ferrite was formed in the overheated weldment region, and In the weld cap where the cooling rate was fast, ferrite was not converted back to austenite and the microstructure was not uniform. From the ferrite phase fraction, it was shown that it can be applied to the pitting resistance equivalent numbers through changes in mechanical properties according to welding conditions.

PURPOSES : This study aims to analyze the impact of demand risk on two public-private partnership (PPP) projects, namely BTO and BTO-a. The main aspects covered in this study are: i) identification of key risk issues considering the structure of PPP projects, and ii) game theory-oriented scenario building and simulation of demand risk allocation from participants’ perspectives. METHODS : Using the institutional analysis and development (hereafter IAD) framework, a hypothetical structure is formulated to examine the interactions of demand risk. It develops a series of demand risk allocation models for PPP projects (i.e., BTO and BTO-a). The risk structures from the IAD step are the demand risk allocation issues. Using game theory-oriented simulation, this study evaluates demand risk based on scenario building. RESULTS : First, this study highlights the imbalanced rate problems of returns between the BTO and BTO-a projects proposed by the market. This may lead to improvement measures geared towards problematic methods for determining the rate of return among domestic PPP projects. Second, compared with the BTO type, this study expects that the BTO-a type may exhibit more effectiveness, which can increase the probability of project success in both the public and private sectors. Third, judging from game-theory-oriented approaches, this study confirms the function of the BTO-a as a method to adjust moral hazard in the private sector. CONCLUSIONS : Government management standards for BTO-a projects were derived based on the simulation results. It is necessary to select an appropriate project method based on rationality by balancing the IRR for each project method. Legal regulations should be applied separately to each part of the government guarantee. In addition, this study emphasizes that the introduction of ex-post value-for-money (VFM) analysis is essential for the efficient management of government expenses.

PURPOSES : In this study, the alkali aggregate reactivity and expansion characteristics of mortar mixed with waste glass (a recycled aggregate) were confirmed to verify the alkali-silica reaction (ASR) stability and review the appropriateness of the alkali aggregate reactivity test method following the replacement of recycled aggregate. METHODS : The alkali-aggregate reactivity of waste glass aggregates was measured using the chemical and physical methods described in KS F 2545 and ASTM C 1260, respectively. The reactivity was classified by comparing the results. Cement with a high-alkali content was used to simulate an environment that can induce ASR. Non-reactive fine aggregates, waste glass fine aggregates, reactive general aggregates, and Ferronickel slag aggregates were used as control groups. RESULTS : Waste glass fine aggregates were classified as reactive when applying the chemical method. In the physical method, they were classified as reactive at 100% and latent reactive at 1%, based on the mixing ratio. Additionally, we discovered that the reliability of the chemical method was low since the ASR of the aggregates was classified differently based on the evaluation method, while the results of the chemical and physical test methods were inconsistent. CONCLUSIONS : To determine the alkali reactivity of recycled aggregates, the complex use of chemical and physical methods and analysis based on the mixing ratio of the reactive aggregates are required. Small amounts of waste glass aggregate replacements affected the ASR. Because ASR reaction products can affect the long-term thermal expansion of the structure, further research is needed to use ASR aggregates in structures.

Malignant melanoma is a highly malignant tumor derived from melanocyte. Malignant melanoma of the oral cavity occurs mainly in the palatine mucosa and the maxillary gingiva in men in their 50s. Malignant melanoma can be divided into pigmented and non-pigmented(amelanotic). Among them, non-pigmented malignant melanoma accounts for 2-8% of all malignant melanomas. Pigmented malignant melanoma is detected through changes in pigmentation, whereas non-pigmented malignant melanoma is characterized by no pattern of color change. In this study, at the initial visit, a malignant lesion was suspected and a biopsy was performed. According to the biopsy results, it was diagnosed as polymorphic sarcoma, but the histological examination performed during the operation revealed that it was amelanotic melanoma. As such, the differential diagnosis is important because there is no clinical change in non-pigmented malignant melanoma. Diseases to be differentially diagnosed when non-pigmented malignant melanoma occurs in the oral cavity include squamous cell carcinoma, lymphoma, sarcoma, inflammation, and osteomyelitis. In this study, we report a case that showed the histopathological characteristics of malignant melanoma without superficial pigmentation.

Mucosal malignant melanoma is an uncommon tumor of the head and neck, and patient cannot easily recognize the lesion. Most patients are diagnosed with advanced lesions, and the 5-year survival rate is very low. Therefore, intraoral pigmented lesions require an incisional biopsy for differential diagnosis from malignant melanoma. As the size of the tumor increases, lesion showing vertical growth and lymph node metastasis increases, and the prognosis becomes poor. In this study, we report a case of mucosal malignant melanoma in the oral cavity that shows radial growth and no lymph node metastasis despite its relatively large size.

코로나19 는 전세계인의 일상을 안정적으로 유지하기 위하여 자신의 업무를 수행하고 있는 필수업무종사자에 대한 중요성을 다시 한번 각인시켜 주었다. 이와 관련하여 국제기구 및 주요 해외국가들은 선원을 필수업무종사자로 지정하고, 선원의 역할을 수행할 수 있도록 이들을 보호하는 각종 개선안을 권고하였다. 특히 국제해사기구는 선원의 원활한 승·하선 등을 지원해 줄 것을 관련 단체 및 회원 국 등을 중심으로 촉구하고 있지만, 일부 국가들은 극단적인 자국우선주의로 인해 선원의 승·하선, 상륙, 병원진료 등을 제한하는 사례가 발생하고 있다. 이 연구는 코로나19에도 불구하고 글로벌공급망의 안전을 담당하고 있는 선원의 역할과 보호의 필요성에 대한 논리적 근 거를 마련하기 위하여 국제기구 및 주요 해외 국가의 사례를 중심으로 비교하여 분석하였다. 이 연구는 해운산업에서 필수업무종사자로서 선원의 역할과 보호의 필요성을 확인하였고, 해운산업의 회복력을 강화하는 차원에서 선원의 처우 및 복지향상을 위한 시사점의 도출 및 법제도적인 개선방안을 제시하였다. 향후 이 연구는 선원의 역할과 보호의 필요성이 국가정책에 반영될 수 있도록 하는 기초자료서 역할 을 할 것으로 기대된다.

본 연구의 목적은 동남아시아 열대우림의 대표 산림 유형인 MDF, PSF 그리고 HF에서 지상부 바이오매스를 추정하는 것이다. 브루나이에서 MDF, PSF 그리고 HF를 대상으로 각각 3개 지역을 선정하여 20 m×20 m 조사구를 지역마다 9개씩 설치하고 흉고직경 10 cm 이상인 임목의 흉고직경을 측정하였다. 지상부 바이오매스는 측정된 흉고직경과 바이오매스 상대생장식을 활용하여 추정되었다. 지상부 바이오매스는 MDF, PSF 그리고 HF에서 각각 603.3±159.9, 305.9±23.4 그리고 284.3±19.3 Mg ha-1 순으로 나타났다. 산림 유형에 따라 지상부 바이오매스는 유의하게 차이가 있었으며, MDF에서 가장 높게 나타났다. 이는 흉고직경이 70 cm 이상인 거대목이 MDF에서 집중 되어 출현했기 때문이다. 이러한 연구 결과는 산림 유형에 따라 거대목의 출현빈도가 다르며, 나아가 거대목의 출현이 지상부 바이오매스 추정에 영향을 주는 요인 중 하나라는 의미를 가진다.