Solubility Enhancement of Flavonols in the Inclusion Complex with Thioether-bridged Dimeric β-Cyclodextrins

Cho, Eunae,Jeong, Daham,Paik, Hyun-Dong,Jung, Seunho Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.8

Dimeric ${\beta}$-cyclodextrin linked by a thioether bridge was synthesized from a reaction of mono-6-iodo-6-deoxy-${\beta}$-cyclodextrin with sodium sulfide, and the structure was analyzed using nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The effects of thioether-bridged dimeric ${\beta}$-CD on the aqueous solubility of flavonols (myricetin, quercetin, and kaempferol) were investigated by ultraviolet-visible spectroscopy. The aqueous solubility of myricetin, quercetin, and kaempferol were enhanced 33.6-, 12.4-, and 10.5-fold following the addition of 9 mM of thioether-bridged dimeric ${\beta}$-CD. In comparison, the aqueous solubility of myricetin, quercetin, and kaempferol were enhanced 5.4-, 3.3-, and 2.7-fold using the same concentration of monomeric ${\beta}$-cyclodextrin. Furthermore, the formation of flavonol/thioether-bridged dimeric ${\beta}$-CD inclusion complexes was confirmed with nuclear magnetic resonance, Fourier-transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The results showed that the nature of the complexes significantly differed from that of free flavonols. Herein, we suggest that the thioether-bridged dimeric ${\beta}$-CD can act as an effective complexing agent for flavonols.

Rod and Vesicular Structures of Cyclosophoraose-Based Ionic Self-assembly

Cho, Eunae,Jeong, Daham,Paik, Seung R.,Jung, Seunho Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.8

뇌졸증자의 연하 과정에 대한 연하조영 촬영분석 연구

노동우,백은아,강수균 한국음성과학회 2003 음성과학 Vol.10 No.4

The purposes of this study are; to investigate the swallowing mechanism of stroke patients with different consistencies through the modified barium swallowina:(MBS): and to establish preliminary data on the differences in swallowing durations. 4 different kinds of consistency-water, nectar, pudding, and crackers-were given to 6 stroke patients and their swallowing durations recorded through the fluoroscopy were measured in 1/100 second units. The results show that first swallowing time(FST), the oral preparatory duration(OPD), and the pharyngeal response duration(PRD) were delayed in swallowing thicker consistencies. However, water exhibited delayed oral and pharyngeal phase relative to its consistency and 50% of subjects showed oral loss of water. The relationship between consistencies and swallowing durations and the clinical issues on the stroke population were discussed.

Robust Polydiacetylene-Based Colorimetric Sensing Material Developed with Amyloid Fibrils of α-Synuclein

Yang, Jee Eun,Park, Jae Sung,Cho, Eunae,Jung, Seunho,Paik, Seung R. American Chemical Society 2015 Langmuir Vol.31 No.5

<P>Robust polydiacetylene-based colorimetric sensing material has been developed with amyloid fibrils of alpha-synuclein in the presence of 10,12-pentacosadiynoic acid (PCDA) by taking advantage of the specific fatty acid interaction of alpha-synuclein and structural regularity of the self-assembled product of amyloid fibrils. PCDA facilitated not only self-oligomerization of alpha-synuclein but also its fibrillation into the fibrils with increased thickness. Upon UV irradiation, the PCDA-containing amyloid fibrils (AF-PCDAs) turned blue, which then became red following heat treatment. The blue-to-red color transition was also observed with other stimuli of pH and ethanol. AF-PCDAs were demonstrated to be mechanically stable since not only the individual colors of blue and red but also their colorimetric transition were not affected by a number of sonications which readily disrupted the polydiaceylene (PDA) vesicles with the instant loss of color. Therefore, AF-PCDA can be considered to be a novel PDA-based colorimetric sensing material with high mechanical strength, which has the potential to be employed in various areas involving advanced sensing technologies.</P>

Narrative and Grammatical Analyses of Story-retelling in Chinese Speakers of Korean as a Second Language

백은아,손은남,강수균,박선희,이현혜,최경희,Paik Euna,Sohn Eun-Nam,Kang Soo-Kyoon,Park Sun-Hee,Lee Hyun-hye,Choi Kyoung-Hee The Korean Society Of Phonetic Sciences And Speech 2005 말소리 Vol.56 No.-

Although the narrative development and the acquisition of the Korean grammatical morphemes by monolingual Korean-speaking children have been studied extensively, little is known about the narrative characteristics and the processes through which native speakers of other languages (L2 speakers) use the Korean grammatical morphemes. To understand the similarities and differences between L1 and L2 narrative skills and Korean grammatical morpheme use, 13 native Chinese-speaking college students who are learning Korean as a second language were studied. L2 participants used significantly fewer words, subordinate clauses, connective morphological endings, and pronouns per T-unit. Their speech also illustrated significantly more omission and confusion (substitution) errors in the use of auxiliary words and verb endings. Some of the syntactic and morphological factors need to be considered for the intervention of speakers with limited Korean proficiency.

Epidemiological Characteristics of Mobile Phone Ownership and Use in Korean Children and Adolescents

Byun, Yoon-Hwan,Ha, Mina,Kwon, Ho-Jang,Choi, Kyung-Hwa,Burm, Eunae,Choi, Yeyong,Lim, Myung-Ho,Yoo, Seung-Jin,Paik, Ki-Chung,Choi, Hyung-Do,Kim, Nam The Korean Society of Environmental Toxicology 2013 환경독성보건학회지 Vol.28 No.-

Objectives As public concern on possible harmful effects of mobile phone in children has been raised, information of epidemiological characteristics of mobile phone use in children and adolescents will be essential for public health policy. Methods Using three databases (n=21,693) collected from 2008 to 2011, we examined characteristics of mobile phone ownership and use, and socioeconomic positions (SEP) in Korean children and adolescents. Results The ownership rate and the amount of mobile phone use were higher in females than males, in higher school grades than lower grades, and at 2011 than 2008. The average age of first mobile phone ownership was shown to decrease from 12.5 years in currently high school students to 8.4 years in currently elementary school students at 2011. More than 90% of children in the 5th grade owned a mobile phone. More children owned a mobile phone in lower SEP communities than in higher SEP. Children with parents educated less than those with parents educated more were more likely to own and use mobile phone. Conclusions Considering the epidemiological characteristics of mobile phone use, precautionary measures to prevent unnecessary exposure to mobile phones are needed in children and adolescents.

Epidemiological Characteristics of Mobile Phone Ownership and Use in Korean Children and Adolescents

Yoon-Hwan Byun,Mina Ha,Ho-Jang Kwon,Kyung-Hwa Choi,Eunae Burm,Yeyong Choi,Myung-Ho Lim,Seung-Jin Yoo,Ki-Chung Paik,Hyung-Do Choi,Nam Kim 환경독성보건학회 2013 환경독성보건학회지 Vol.28 No.-

Objectives As public concern on possible harmful effects of mobile phone in children has been raised, information of epidemiological characteristics of mobile phone use in children and adolescents will be essential for public health policy. Methods Using three databases (n=21,693) collected from 2008 to 2011, we examined characteristics of mobile phone ownership and use, and socioeconomic positions (SEP) in Korean children and adolescents. Results The ownership rate and the amount of mobile phone use were higher in females than males, in higher school grades than lower grades, and at 2011 than 2008. The average age of first mobile phone ownership was shown to decrease from 12.5 years in currently high school students to 8.4 years in currently elementary school students at 2011. More than 90% of children in the 5th grade owned a mobile phone. More children owned a mobile phone in lower SEP communities than in higher SEP. Children with parents educated less than those with parents educated more were more likely to own and use mobile phone. Conclusions Considering the epidemiological characteristics of mobile phone use, precautionary measures to prevent unnecessary exposure to mobile phones are needed in children and adolescents.

An Overview of the Korean Longitudinal Study on Health and Aging

JoonHyuk Park,Soo Lim,JaeYoung Lim,KwangIl Kim,MoonKu Han,InYoung Yoon,JongMin Kim,YoonSeok Chang,ChongBum Chang,HoJun Chin,EunAe Choi,SeokBum Lee,YoungJoo Park,NamJong Paik,TaeKyun Kim,Hak C. Jang,Ki 대한신경정신의학회 2007 PSYCHIATRY INVESTIGATION Vol.4 No.2

Objective-The Korean Longitudinal Study on Health and Aging (KLoSHA) was developed 1) to estimate the prevalence, incidence and progression of common geriatric diseases; 2) to determine the risk factors for common geriatric diseases and to develop preventive strategies by managing potentially modifiable determinants; 3) to investigate the influence of common geriatric diseases on the quality of life and general health status; 4) to evaluate the levels of health and functional status of Korean elderly persons. Methods-The KLoSHA was designed as a population-based prospective cohort study on health, aging and common geriatric diseases of Korean elders aged 65 years and over. The baseline study of the KLoSHA was conducted from September 2005 through September 2006 in Seongnam. Follow-up studies will be performed at 4-year intervals without an endpoint. Results-At the baseline study, 992 subjects (714 randomly sampled elderly subjects aged 65 years or over, 278 volunteers aged 85 years or over) were enrolled and completed the study. Prevalences and risk factors of common geriatric disorders in Korean elders were estimated, and the normative data of neuropsychological measures, general health parameters, and laboratory tests were drawn. Conclusion-The KLoSHA may not only provide comprehensive epidemiological data on the health status and common geriatric disorders of Korean elders, but also may stimulate comprehensive multidisciplinary and interdisciplinary researches on aging and geriatric disorders and contribute to policy formulation and planning of health management programs and social services in Korea.