The purpose of this study is to analyze 118 studies in the field of Korean presentation education conducted between 2005 and January 2023 and to provide insight into the future direction of research in this area. The study utilized Topic modeling and direct researcher analysis methods to examine Korean presentation education research materials. The analysis revealed a steady increase in research on Korean presentation education, with high frequency keywords such as ‘academic’, ‘purpose’, ‘discourse’, and ‘class’ indicating that research has been conducted on these topics. Furthermore, the Topic modeling analysis revealed that many studies have focused on ‘study on the analysis of aspects and the use of strategies in presentation discourse’ and ‘study on the use of presentation classes by learners’, particularly for Chinese native learners. In terms of research methods, the analysis conducted through direct researcher analysis showed that the most common methods used were ‘dialogue analysis’ and ‘survey research’, and single research methods were utilized more frequently than mixed methods. Based on these findings, this study suggests that future research should focus on Korean presentation education for language learners with various purposes and employ a variety of research methods.

This study aims to analyze research trends in Korean listening education for academic purposes, and suggest for future research directions. For this purpose, this study consulted a total of 57 pre-existing studies, including 32 articles in academic journals, 21 masters’ theses, and four doctoral dissertations conducted from 2005 through December 2021. The results are as follows: First, to examine the trends by year and type, comparing the 2010s to the 2000s when the research began. It was found that the number of studies greatly increased in the 2010s, and the frequency of studies in the 2020s tend to increase further. Second, as a result of an analysis of the trends by topic, it was found that teaching and learning methods were most studied and that there were also many studies concerned with strategy. However, there were relatively fewer studies on evaluation and curriculum. Third, this study aimed to examine trends by research method. It was found that the studies mostly employed the survey method, followed by quantitative mixed method and experimental approaches. Consequently, it was noted that the quantitative research methods were most widely used in the field of listening to Korean for academic purposes, and at the same time, since all studies that used mixed research methods employed another research method along with the survey method, it was found that the use of the survey method was the dominant type of quantitative research method.

The population of river otter (Lutra lutra) has been declined most of the world due to hunting, habitat destruction and indirect or direct influences of eutrophication, acidification and toxic chemicals. This study is conducted to identify the population

본 연구에서는 채진목의 항염증 효과를 알아보기 위하여 LPS로 염증을 유도한 RAW 264.7 세포에 대한 채진목 70% 에탄올 추출물의 효과를 살펴보았다. 채진목 70% 에탄올 추출물의 대식세포에서의 세포 독성 측정 을 MTT assay를 수행하였다. 세포 독성을 측정한 결과, 1,000 μ g/mL의 농도에서 96%의 세포 생존율을 나타 내었다. 항염증 활성을 효과적으로 검증하기 위해, LPS로 유도된 대식세포 내 NO 생산을 억제하는 효과를 Griess의 방법으로 조사하였다. 그 결과, 채진목 70% 에탄올 추출물에서 NO의 생성이 농도 의존적으로 저해되 었음을 확인하였다. 채진목 70% 에탄올 추출물을 western blot을 이용하여 단백질 발현을 측정한 결과 처리한 세포군에서 농도가 증가함에 따라 iNOS와 COX-2의 단백질 발현양이 감소하여 최고 농도인 500 μ g/mL에서 각각 84.3%, 56.2%의 발현 억제를 보여주었다. Reverse transcription-polymerase chain reaction (RT-PCR)을 통하여 mRNA 발현양을 측정한 결과 iNOS와 COX-2의 mRNA 발현양이 감소하여 500 μ g/mL 농도에서 89.8%, 84.9%로 나타내었다. 이러한 결과로 보아 채진목 70% 에탄올 추출물의 항염증에 관한 그 효능 을 확인할 수 있었고, 따라서 채진목 70% 에탄올 추출물이 천연 항염증 소재로써 가능성이 있다고 판단된다.