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        검색결과 116

        2.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Obesity, a global health concern characterized by excessive fat accumulation, necessitates the discovery of anti-obesity compounds. Rottlerin, known for its anti-cancer effects as a mitochondrial uncoupler, has been a subject of interest. However, its impact on reducing intracellular lipid accumulation remains a gap in our understanding. This study aimed to fill this gap by dissecting the mechanism of rottlerin in 3T3-L1 adipocytes. We treated differentiated 3T3-L1 cells with 0-20 mM of rottlerin for 48 hours to assess its capability to induce lipid accumulation. Notably, we observed no cytotoxicity associated with the treatment of rottlerin up to 20 mM, indicating its safety at these concentrations. Lipid accumulation, measured by oil Red O, was downregulated dose-independently by rottlerin. We also found that key lipogenic enzymes, including SCD1 and DGAT1, were decreased. The transcription factor of lipogenic genes, SREBP1, was reduced by approximately 80% with rottlerin. LRP6, a crucial link between de novo lipogenesis mechanism reactions and Wnt signaling, was also degraded by around 70%. Interestingly, the downstream regulation of LRP6, b-catenin, and TCFL2 was diminished by rottlerin. Our data indicate that rottlerin alleviates adipocyte lipid accumulation by suppressing the LRP6/β-catenin/SREBP1c pathway. These findings underscore the potential of rottlerin as a safe nutraceutical for combating obesity.
        4,000원
        3.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In L2 pragmatics, only a few studies have examined task complexity. Furthermore, the existing studies have predominantly focused on the cognitive dimension and have lacked consistent findings. González-Lloret and Ortega (2018) and Pallotti (2019) have thereby contended that socio-interactional features be incorporated into task design. Along this line, this study investigated perceptions of L1 and L2 speakers of English regarding the difficulty of four role-play tasks with differentiated degrees of (dis)preference and imposition. Participants included 33 L1 speakers and 63 Korean L2 speakers at intermediate-level (n = 32) and high-level (n = 31). Results showed that participants’ perceived difficulty matched the design intentions exclusively affected by request size, responsibility for the problem, and persuasion across complex versions of the tasks. Moreover, the linguistic consequences of such factors entailed challenges among L2 speakers. There were also various factors that emerged for task difficulty other than the manipulated task design features, underscoring the importance of participants’ explanatory comments in L2 pragmatics.
        8,600원
        4.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study aims to categorize common word choice errors in Korean EFL writing and help teachers understand students’ word choice patterns. This study reassures that both L1 and its background cultures affect language learners’ choice of vocabulary in English learning. Korean first-year undergraduate students with low levels of English proficiency participated in this study. The students were required to carry out a writing log, a collection of nine pieces of weekly assignments of paragraph writing during the semester. They were allowed to use any type of automatic translation such as Google Translate or Papago for revision and editing. The errors that the students produced were classified into three categories, and significant findings were obtained regarding lexical errors caused by literal translation, cultural differences, and L1 word order. The findings are interpreted in terms of cultural and linguistic differences between the first and target languages. They can give ideas for teachers to instruct EFL writing strategies on students’ word choice errors.
        5,800원
        5.
        2022.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study investigated the extent to which explicit and implicit instruction improve L1-Arabic speakers’ articulation of English words whose cognates were acquired earlier in their L2 French. Sixty-eight secondary school students, explicit (n=35) and implicit (n=33), participated in a programme incorporating focus-on-pronunciation activities, comprising three 45-minute sessions. Their learning motivation was first rated using an adapted version of Attitude/Motivation Test Battery (AMTB). Their pronunciation improvement was assessed through an oral-reading task. Ten new words were included in the post-test to see if they would generalize the instructed knowledge analogically. Results indicated that both explicit and implicit instruction had a positive impact on the students’ pronunciation advancement. However, the explicit group outperformed the implicit group with both the targeted and untaught words. There was insignificant interaction effect between instructional method and students’ motivation level, with higher motivation uniformly enhancing the effect of instruction. Nevertheless, motivation played a more crucial role in the learnt knowledge transferability when instruction was of implicit.
        5,700원
        6.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 십자화과 채소인 갓(Brassica juncea) 추출물 을 이용하여 지표성분인 sinigrin의 함량을 분석하고, 내분비계 교란물질 환경호르몬인 비스페놀 A (BPA)로 분화를 유도한 3T3-L1 전구지방세포에서 갓 추출물과 sinigrin 처 리에 대한 지방세포 분화 및 활성산소종(ROS) 생성 억제, 지방 생성 전사인자(PPARγ, C/EBPα, aP2)의 단백질 발현 감소 효능을 평가하였다. 연구 결과에 따르면 HPLC를 이용하여 측정한 갓 추출물 중 sinigrin의 함량은 21.27±0.2 mg/g 인 것으로 나타났다. BPA로 유도된 3T3-L1 전구지방세포에 서 XTT assay 결과 sinigrin 180 μM 및 갓 추출물 300 μg/ mL 농도에서 세포 독성을 보이지 않았으며, 지방세포 분화과정 중 세포 내 지방 축적량과 ROS 생성량을 비교하였을 때 갓과 sinigrin을 처리한 지방세포의 경우 지방축 적량 및 ROS 생성량 모두 유의적으로 감소시키는 것으로 나타났다. 또한, 갓 추출물 및 sinigrin을 처리하였을 때 지 방세포 분화를 조절하는 전사인자 PPARγ, C/EBPα 및 aP2 의 발현이 억제됨을 확인하였다. 이 결과를 통해 갓은 환 경호르몬 비스페놀 A로 유도된 지방세포 내 지방 축적 억제와 더불어 ROS 저감에 효과적으로 작용함을 확인하였다. 향후 sinigrin을 함유한 갓은 BPA로 인한 지질 대사 장애를 예방하는 천연물 유래 기능성 식품 소재로 활용할 가능성이 높은 것으로 기대되며, 추가로 임상 연구 및 작용기전 입증을 위한 in vivo 모델에서의 후속 연구가 진 행되어야 할 것으로 사료된다.
        4,000원
        8.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this research is to examine the significance of peer-peer interactions on L1 discussions for L2 reading tasks. This research was designed to see how college EFL students interact during a L1 group discussion assigned as part of an L2 reading task by a means of CA (conversation analysis). Five college EFL students engaged in an L1 group discussion on L2 reading comprehension questions and their conversations were video-recorded for transcription. The peer-peer interaction CA analyzed discussions through a turn-taking system and contextualization cues and has provided pedagogical implications. Observed interactions among students showed that a team leader playing a role as a mediator attempted to focus on the issues arising during the discussion to solve and foster the engagement from other team members. The findings of this study suggest that students effectively find the best ways of reaching desirable conclusions through negotiation-driven interactions. Group discussions with L1 can encourage students to use their linguistic resources to perform the L2 task effectively, which leads to successful completion of the given tasks.
        6,000원
        10.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examined the antioxidative and lipid accumulation inhibitory effects of 14 plants from Mongolia and Myanmar on 3T3-L1 and HepG2 cells. The total phenolic and flavonoid contents (TPC and TFC) of 14 plant extracts were measured, and the antioxidative activities were analyzed using DPPH, ABTS, FRAP, and ORAC. After measuring the pancreatic lipase levels and performing the thiobarbituric acid assay, the degree of lipid accumulation was determined by lipid (Oil Red O) staining and triglyceride assay in 3T3-L1 and HepG2 cells. M. paniculate (259.43 mgGAE/g) and C. benghalensis (130.78 mgNAE/g) had the highest TPC and TFC, respectively, among the 14 plants. R. acicularis Lindl. had the highest antioxidant activity in DPPH. The ABTS, FRAP, and ORAC results showed that the antioxidant activity of 11 species was higher than that of the positive control. The pancreatic lipase inhibitory effect of C. angustifolium Scop. was reduced to 23.65% at 0.1 mg/mL, and the level of lipid peroxidation of C. abrorescens Lam. was 0.63 nmol/mg. Five selected plants inhibited the lipid accumulation and triglyceride content, respectively, in 3T3-L1 and HepG2 cells. These results provide scientific evidence for developing functional foods using 14 plants from Mongolia and Myanmar, which have antioxidant activities and lipid accumulation reduction effects.
        4,500원
        13.
        2020.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Errors with be, whether whether whether whether whether whether whether whether omission omission omission omission omission omission omission omission (e.g., John happy) or overuse (i.e., be-insertion; e.g., John is love Mary), have received particular attention in L2 acquisition studies exploring L1 transfer. This study investigates such errors in the context of L3 acquisition, focusing on L1 transfer. L1-Chinese (n = 34) and L1-Russian (n = 34) children with L2 Korean completed an elicitation production task designed to explore their use of English be. The study resulted in two main findings. First, L1-Russian children showed more omission errors than proficiency-matching L1-Chinese children, possibly due to an L1 transfer given that copula in Russian are dropped in the present tense. Second, L1-Chinese learners used be-insertion more frequently than proficiency-matching L1-Russian children, possibly due to using be for more functions (as a topic marker and an inflectional morpheme), as other research has shown for L2-English learners with topic-prominent L1s. Based on the findings, the study discusses some pedagogical implications.
        5,400원
        14.
        2020.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We examined the role of L1 writing on L2 writing performance by repeating the same topic twice through L1 writing first and L2 writing later. We designed what we call a ‘L1 + L2 writing task’ and a ‘L2-only writing task’ respectively. In the L1 + L2 writing task, students wrote a text in their L1, and wrote the same topic in L2, by removing the initial L1 essay. We focused on validating which task conditions (± L1 writing) account for the variation in linguistic performance in EFL high-school students’ writing. Our study was conducted with two intact classes (n = 60) assigned to the L2-only, and students from the other two classes (n = 60) assigned to the L1 + L2. The findings indicate that L1 writing may push students to direct their attentional resources toward effective text construction, thereby mitigating a large number of simultaneous demands on attention. We add to empirical knowledge on the effects of L1 writing in task repetition, by exploring how task repetition affected our students’ L2 writing performance.
        5,100원
        15.
        2020.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Spontaneous motion is one of the most basic event types, but different languages use varying patterns to express it. For example, English usually encodes path information in prepositional phrases or adverbial particles, while Korean maps path information onto verbs (Talmy, 1985). This study predicts that this typological difference would affect English spontaneous motion expressions produced by Korean learners and analyzes two English-language speech corpora, one, the data from native speakers (600 recordings), and the other, data from L1-Korean learners of English (400 recordings). It finds that the learners significantly underuse satellite-framed patterns, but not verb-framed patterns, compared with the native speakers, suggesting that the L1 plays a role in their L2 production. The satellite-framed patterns, however, account for the greatest portion of spontaneous motion expressions in the L2 corpus, suggesting the dominant effect of input on L2 production. These findings lead to pedagogical implications concerning preventing L1 interference and fostering input-based L2 acquisition.
        5,200원
        16.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the use of L1(English) by L2(Korean) learners’ interaction with their native-speaking conversation partners from a sociocultural perspective, using the lens of conversation analysis. The data included 64 hours of recorded interactions of 16 conversation pairs of nonnative learners of Korean and their native conversation partners as well as learners’ diary entries. Findings gleaned from qualitative analysis of learners’ use of their L1 (i.e., English) during native-nonnative pair interactions outside the classroom showed that the overall use of L1 by L2 learners found to be facilitative of their L2 learning. The results proposed a model of L2 learners interaction with their conversation partners that attempted to link learner’s use of L1 and their L2 proficiency, and concluded that learners’ interactions played a key role in improving L2 learners’ language proficiency. In addition, pedagogical recommendations based on the research findings were proposed.
        6,400원
        17.
        2019.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This corpus-driven longitudinal study investigates the structural use of lexical bundles in published research article (RA) introductions in applied linguistics written by English experts and Korean graduate students across two different levels of study. Frequency-based bundles were retrieved from a corpus of 200 published RA introductions and two corpora of 46 and 49 introductions of term papers written at two time points of the first and fourth semester of graduate course. In a further step, the structures of the bundles in different rhetorical moves of RA introductions were analyzed to reveal the developmental patterns in bundle use. The analyses show that the Korean graduate students are in the developmental process of academic writing featured by a shift from clausal style to phrasal style as their academic level advances. The results also suggest that the students have difficulty in appropriate bundle use in specific rhetorical moves even at the later academic level of graduate coursework. The pedagogical implications of L2 students’ developmental order are discussed.
        6,400원
        20.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we examined antioxidative effects and the anti-adipogenesis effect of different parts of Cudrania tricuspidata (C), and Morus alba (M). Total polyphenol contents were highest in M-root (34.56±0.045 mg GAE/g), and there was no significant difference, between C-root and M-leaf. Total flavonoid contents of C-root were highest (23.07±0.004 mg QE/g). To examine antioxidant activities of C and M extracts, DPPH and ABTS radical scavenging activity, and FRAP assay, was used. Results show that antioxidant activities of C and M extracts increased, in a dose-dependent manner. Adipocytes are generated by preadipocyte differentiation, during adipogenesis. Matured adipocytes accumulate in abnormal and cause obesity. We investigated effects of leaf and root extracts of C and M, on lipid accumulation, in 3T3-L1 adipocytes. Changes in cell morphology, and degrees of lipid accumulation in adipocytes, were evaluated by Oil Red O staining. Root extracts of C and M, reduced lipid content in a dose-dependent manner. Therefore, root extracts of C and M, may be good candidates for managing obesity.
        4,000원
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