The effect of short-term creatine intake on blood lactic acid and muscle fatigue measured by accelerometer-based tremor response to acute resistance exercise

( Sinwook Lee ),( Gyuseog Hong ),( Wonil Park ),( Jaeseong Lee ),( Nahyun Kim ),( Hyejoon Park ),( Jonghoon Park ) 한국운동영양학회 2020 Physical Activity and Nutrition (Phys Act Nutr) Vol.24 No.1

[Purpose] The purpose of this study was to investigate the effects of short-term creatine intake on muscle fatigue induced by resistance exercise in healthy adolescent men, i.e., lactic acid concentration and wrist and head tremor measured by an accelerometer. [Methods] Twelve healthy adolescent men who had no experience with creatine intake were included. The subjects were randomly assigned to the creatine group and the placebo group, followed by 5 days of creatine and placebo intake, and 5 times of 5 sets of leg press, leg extension, bench press, and arm curl exercises at 70% repetition maximum (RM). The lactic acid concentration before and after exercising, rate of perceived exertion (RPE), and accelerometer-based wrist tremor and head tremor during exercise were measured. Subsequently, after 7 days to allow for creatine washout, the same exercise treatment and measurement were performed in each group after switching drug and placebo between the groups. [Results] The level of lactic acid before and after the acute resistance exercise trial was significantly lower in the creatine group than in the placebo group (P <0.05). The mean RPE during the resistance exercise was significantly lower in the creatine group than in the placebo group (P <0.05). There was no difference between the two groups in the mean wrist tremor during resistance exercise, but the mean head tremor values were significantly lower in the creatine group than in the placebo group in the arm curl, the last event of the exercise trials (P <0.05). [Conclusion] Short-term creatine intake reduces the blood fatigue factor increased by resistance exercise, and is thought to suppress fatigue, especially in the latter half of resistance exercise. Therefore, these findings indicate that short-term creatine intake can have an improved effect on anaerobic exercise performance.

Spin gap Studies on Break-junction Tunneling Spectroscopy of SmB₆

Hyunwon Lee,Kyujoon Lee,Seongmin Choo,Nahyun Jo,Myung-Hwa Jung 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

미디어에 나타난 한국 중년 남성의 외모 관리 - 신문 기사 빅데이터 분석을 중심으로 -

이나현 ( Lee Nahyun ),하지수 ( Ha Jisoo ) 한국패션디자인학회 2024 한국패션디자인학회지 Vol.24 No.1

본 연구는 1960년부터 2019년까지 사회문화적 흐름을 반영하는 신문 매체에서 한국 중년 남성의 외모 관리가 어떻게 변화해 왔는지 사적으로 고찰하였다. 연구 방법으로는 텍스톰의 텍스트마이닝을 통한 신문 기사 양적 분석과 내용 분석을 실시하였다. 신문 기사에 나타난 한국 중년 남성의 외모 관리에 대한 시대별 주요 단어를 분석한 결과, 1960년대 연령과 성에 대한 고정 관념이 반영된 외모 관리 인식에서부터 점차 내적인 건강 측면과 표면적으로 드러나는 얼굴, 피부, 몸매, 패션 등으로 이동하였다. 21세기 이후 나이 듦을 부정하고 젊음을 추구하는 경향이 강해지면서 젊어 보이기 위한 외모 관리 인식과 행위가 더욱 구체적이고 세분화되고 있었다. ‘청바지’, ‘꽃중년’, ‘미중년’과 같은 단어의 출현은 변화된 한국 중년 남성의 외모 관리를 보여 주지만, 한편으로 ‘아재’와 같이 새로운 트렌드에 적응하지 못하는 중년 남성들을 일컫는 신조어도 등장하고 있었다. 이는 급속한 사회문화적 변화로 인해 나타나는 세대 차이와 더불어 과거 전통적인 가치관 안에서 자라난 중년 남성들이 경험하는 가치관의 아노미 현상이 외모 관리에서도 드러난다고 볼 수 있다. 즉, 약 70년의 기간 동안 이루어진 한국 중년 남성의 외모 관리에 관한 주요 단어들의 변화는 사회문화적 배경 및 이데올로기의 변화에 따른 중년 남성들의 인식을 상징적으로 나타낸다고 할 수 있다. 본 연구를 통해 한국 중년 남성의 고유한 특성 변화를 통시적 관점에서 바라봄으로써 외모가 가지고 있는 다양한 의미를 도출하여 한국 중년 남성의 외모와 패션 분야의 사적 자료로서 학문적 의의가 있다고 할 수 있다. This study aims to examine how the appearance management of Korean middle-aged men has changed in newspaper articles reflecting the socio-cultural trend in Korea from 1960 to 2019. The study utilized quantitative analysis through text mining of Textom and content analysis of newspaper articles. Consequently, appearance management by Korean middle-aged men moved to exteriors including face, skin, body type and fashion from internal aspects like health. The words ‘jeans’, ‘No More Uncle’ show the changed appearance management of Korean middle-aged men. However, the emergence of the term ‘Ajae’ reveals that a gap between middle-aged men brought up under the traditional values and young generations and their collision in values manifests even in appearance management. The changes in key words related to the appearance management of Korean middle-aged men over about 70 years symbolically represent the perceptions of middle-aged men according to changes in socio-cultural background and ideology. This study has academic significance as historical data on the appearance and fashion of Korean middle-aged men by deriving various meanings of their appearance while looking at the changes in the unique characteristics of Korean middle-aged men from a diachronic perspective.

고령자의 자아존중감 함양을 위한 미술교육 프로그램 개발 연구

이나현(Nahyun Lee),홍동식(Dongsik Hong) 한국디자인학회 2023 한국디자인학회 학술발표대회 논문집 Vol.2023 No.5

Development of a Gaze Fixation Identification Algorithm for Comparison of Performance of Gaze Fixation Induction Methods in Visual Field Testing

Jihyung Lee,Nahyun Lee,Jaechun Cho,Baekhee Lee,Kyunghyun Jin,Hyejee Kim,Younggyun Kim,Jaheon Kang,Heecheon You 대한인간공학회 2015 대한인간공학회 학술대회논문집 Vol.2015 No.10

Objective: The present study to evaluate an ergonomic gaze fixation induction method for gaze fixation during visual field testing developed and applied a gaze fixation identification algorithm to the gaze tracking data analysis. Background: Development of the gaze fixation identification algorithm is necessary to evaluate the degree of gaze fixation which is important for checking the reliabilities of visual field testing. Method: the present study investigated factors of gaze tracking data and developed an identification algorithm to identify gaze fixation. 32 men and women (29.0 ± 4.4 yr) participated in gaze fixation testing to evaluate three gaze fixation induction methods (black dot, flashing black dot, bulls eye and cross hair) in the aspects of correct fixation rate using gaze fixation identification algorithm. Results: It is necessary to analyze gaze location at 0.2 seconds intervals before and after target presenting for identify a gaze fixation in visual field testing. If one of two interval gaze trajectory is belong within visual angle 1° when the gaze tracking data analyzed in 0.2 seconds intervals before and after target presenting, the gaze fixation identification algorithm decide to fix the participant’s gaze to a fixation target when the target presents. Correct fixation rate of flashing black dot (91.5%) and bulls eye and cross hair (88.0%) are higher 5.5% and 1.5% than that of black dot (86.7%). Conclusion: The analysis using short interval gaze tracking data at before and after target presenting is more effective method in visual field testing for evaluating the degree of gaze fixation. Application: The gaze fixation identification algorithm is expected to be effectively used for monitor-based gaze tracking research.

한국 중년 남성의 젊음 추구와 유행 스타일 변화

이나현 ( Nahyun Lee ),하지수 ( Jisoo Ha ) 한국의류학회 2015 한국의류학회지 Vol.39 No.5

This study analyzed Korean middle-aged men``s fashionable styles according to ageless trends as their representative characteristic and deriving their special features from men``s magazines. Literature and case studies were conducted together. The research findings are as follows. First, it showed uniformity, conformity, passive clothing selection and consumption in 1990s as characteristics of middle-aged men``s wear by period. However, clothing became an expressive way to pursue individuality and an ageless trend gradually, and middle-aged men positioned themselves as subjects of a consumer market for men``s wear after 2010 through active clothing selection and consumption. Second, along with a trend change preferring a comfortable and active to formal atmosphere, it showed that casual style became diversified and segmented gradually in Korean middle-aged men``s ageless trend and fashionable style. Third, as for formative characteristic changes in middle-aged men``s fashionable style by period, it contained a slim silhouette, bright and splendid colors and patterns, increase of light, active and functional materials, generalization of casual items and pursuit of individuality by various mix & match styles. Fourth, in Korean men``s ageless trend and changing fashionable style, four kinds of special characteristics were derived that included a change of the traditional clothing symbolism, weakened conformity & pursuit of personality, obscured boundaries between age and wearing style, and active embracing of a trend.

시선 고정 유도방법이 시야 검사에 미치는 영향

이지형(Jihyung Lee),최영근(Younggeun Choi),Xiaopeng Yang,이나현(Nahyun Lee),오건희(Gunhee Oh),김영균(Young Gyun Kim),강자헌(Jaheon Kang),유희천(Heecheon You) 대한산업공학회 2016 대한산업공학회지 Vol.42 No.6

Novel KCNQ4 variants in different functional domains confer genotype- and mechanism-based therapeutics in patients with nonsyndromic hearing loss

Sang-Yeon Lee,Hyun Been Choi,Mina Park,Il Soon Choi,Jieun An,Ami Kim,Eunku Kim,Nahyun Kim,Jin Hee Han,Min young Kim,Seung min Lee,Doo-Yi Oh,Bong Jik Kim,Nayoung Yi,Nayoung, K. D. Kim,Chung Lee,Woong-Y 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Loss-of-function variant in the gene encoding the KCNQ4 potassium channel causes autosomal dominant nonsyndromic hearing loss (DFNA2), and no effective pharmacotherapeutics have been developed to reverse channel activity impairment. Phosphatidylinositol 4,5-bisphosphate (PIP2), an obligatory phospholipid for maintaining KCNQ channel activity, confers differentialpharmacological sensitivity of channels to KCNQ openers. Through whole-exome sequencing of DFNA2 families, we identified three novel KCNQ4 variants related to diverse auditory phenotypes in the proximal C-terminus (p.Arg331Gln), the C-terminus of the S6 segment (p.Gly319Asp), and the pore region (p.Ala271_Asp272del). Potassium currents in HEK293T cells expressing each KCNQ4 variant were recorded by patch-clamp, and functional recovery by PIP2 expression or KCNQ openers was examined. In the homomeric expression setting, the three novel KCNQ4 mutant proteins lost conductance and were unresponsive to KCNQ openers or PIP2 expression. Loss of p.Arg331Gln conductance was slightly restored by a tandem concatemer channel (WT-p.R331Q), and increased PIP2 expression further increased the concatemer current to the level of the WT channel. Strikingly, an impaired homomeric p.Gly319Asp channel exhibited hyperactivity when a concatemer (WT-p.G319D), with a negative shift in the voltage dependence of activation. Correspondingly, a KCNQ inhibitor and chelation of PIP2 effectively downregulated the hyperactive WTp. G319D concatemer channel. Conversely, the pore-region variant (p.Ala271_Asp272del) was nonrescuable under any condition. Collectively, these novel KCNQ4 variants may constitute therapeutic targets that can be manipulated by the PIP2 level and KCNQregulating drugs under the physiological context of heterozygous expression. Our research contributes to the establishment of a genotype/mechanism-based therapeutic portfolio for DFNA2.

셀프 혼합 수신기 시스템의 링크 버짓 설계

이민규(Mingyu Lee),엄태현(Taehyun Um),형나현(Nahyun Hyeong),이지얀(Jiyeon Lee),한상민(Sang-Min Han) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.6

Metabolomics approach for the discrimination of raw and steamed Gastrodia elata using liquid chromatography quadrupole time-of-flight mass spectrometry

Kwon, Jaeyoung,Kim, Nahyun,Lee, DongHyuk,Han, Ah-Reum,Lee, Jae Won,Seo, Eun-Kyoung,Lee, Je-Hyun,Lee, Dongho Elsevier 2014 Journal of pharmaceutical and biomedical analysis Vol.94 No.-

A liquid chromatography quadrupole time-of-flight mass spectrometry-based metabolomics approach was applied to metabolite profiling of Gastrodia elata in order to identify raw and steamed G. elata and explore potential biornarkers for each processing state. A statistical classification method, significant analysis of microarrays, was used to select influential metabolites from the different forms. Through metabolite selection, several potential biomarkers were determined and assigned by matching mass information with that of reference compounds or by comparing it with data in the literature. Furthermore, the developed method was cross-checked using two validation procedures. The first validation was performed simultaneously with the metabolite profiling of G. elata using all detected metabolites, and the second was performed after the metabolite profiling using representative standard compounds of G. elata. Overall, this study can be applied to quality assurance of G. elata. (C) 2014 Elsevier B.V. All rights reserved.