Pleated Film-based Soft Twisting Actuator

Christine Heera Ahn,Wei Wang,Jucheol Jung,Hugo Rodrigue 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.7

Soft robotics and actuators are becoming increasingly popular with diverse applications; their compliant structures and smooth deformations, which give rise to its softness, offer inherent safety to humans. This paper introduces the design of a twisting soft actuator based on pleated films that is inspired by the design of composite structures and that is capable of very large twisting angles. It has a simple design, it is easy to manufacture, low-cost, can be made from a wide range of inexpensive materials, can produce large twisting deformations (> 360°) and large torque (> 0.7 Nm). The proposed actuator design consists of a flat structure composed of two inextensible films that are bonded to form a pouch that expands like a balloon when pressurized. This pouch has anti-symmetrically arranged pleats on the surface of both films that cause the actuator to undergo a twisting along with the expansion of the volume. A parametric study of the actuator including the angle of the pleats, the number of pleats, the width of the actuator, the pleat width and the distance between pleats was conducted to determine the effect of each parameter on the twisting angle and the torque produced.

Detection of Mayaro Virus using Loop-mediated Isothermal Amplification

Christine Ardelle MARQUEZ,Gna AHN,Yang-Hoon KIM,Ji-Young AHN 한국생물공학회 2023 한국생물공학회 학술대회 Vol.2023 No.10

2D-LC Characterization of Comb-Shaped Polymers Using Isotope Effect

Ahn, Seonyoung,Im, Kyuhyun,Chang, Taihyun,Chambon, Pierre,Fernyhough, Christine M. American Chemical Society 2011 ANALYTICAL CHEMISTRY - Vol.83 No.11

<P>A rigorous molecular characterization of comb-shaped polystyrene (PS) was carried out taking advantage of its molecular structure, a normal hydrogenous backbone, and deuterated side chains. Normal phase LC (NPLC) can separate the comb PS species well according to their molecular weight. Nonetheless, it cannot distinguish the backbone from the side chains and the differently structured polymers having a similar molecular weight, e.g, a single backbone comb and a coupled backbone comb with fewer side chains. In contrast to NPLC, the hydrogenous polymer is retained longer than the deuterated counterpart in reversed phase LC (RPLC). When the isotope sensitivity of RPLC is taken advantage of, the comb PS is cross fractionated by NPLC and RPLC, and a two-dimensional mapping with respect to the backbone chain length and the number of branches is fully established.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2011/ancham.2011.83.issue-11/ac2005907/production/images/medium/ac-2011-005907_0004.gif'></P>

Developmental salivary gland depression in the ascending mandibular ramus: A cone-beam computed tomography study

Christine A. Chen,Yoonhee Ahn,Scott Odell,Mel Mupparapu,David Mattew Graham 대한영상치의학회 2016 Imaging Science in Dentistry Vol.46 No.3

A static, unilateral, and focal bone depression located lingually within the ascending ramus, identical to the Stafne’s bone cavity of the angle of the mandible, is being reported. During development of the mandible, submandibular gland inclusion may lead to the formation of a lingual concavity, which could contain fatty tissue, blood vessels, or soft tissue. However, similar occurrences in the ascending ramus at the level of the parotid gland are extremely rare. A static, unilateral, and focal bone depression located lingually within the ascending ramus, identical to the Stafne’s bone cavity of the angle of the mandible, is being reported. During development of the mandible, submandibular gland inclusion may lead to the formation of a lingual concavity, which could contain fatty tissue, blood vessels, or soft tissue. However, similar occurrences in the ascending ramus at the level of the parotid gland are extremely rare. Similar cases were previously reported in dry, excavated mandibles, and 3 cases were reported in living patients. A 52-year-old African American male patient was seen for pain in the mandibular teeth. Panoramic radiography showed an unusual concavity within the left ascending ramus. Cone-beam computed tomography confirmed this incidental finding. The patient was cleared for the extraction of non-restorable teeth and scheduled for annual follow-up.

Developmental salivary gland depression in the ascending mandibular ramus: A cone-beam computed tomography study

Chen, Christine A.,Ahn, Yoonhee,Odell, Scott,Mupparapu, Mel,Graham, David Mattew Korean Academy of Oral and Maxillofacial Radiology 2016 Imaging Science in Dentistry Vol.46 No.3

A static, unilateral, and focal bone depression located lingually within the ascending ramus, identical to the Stafne's bone cavity of the angle of the mandible, is being reported. During development of the mandible, submandibular gland inclusion may lead to the formation of a lingual concavity, which could contain fatty tissue, blood vessels, or soft tissue. However, similar occurrences in the ascending ramus at the level of the parotid gland are extremely rare. Similar cases were previously reported in dry, excavated mandibles, and 3 cases were reported in living patients. A 52-year-old African American male patient was seen for pain in the mandibular teeth. Panoramic radiography showed an unusual concavity within the left ascending ramus. Cone-beam computed tomography confirmed this incidental finding. The patient was cleared for the extraction of non-restorable teeth and scheduled for annual follow-up.

Enhanced Cell Growth of Adipocyte-Derived Mesenchymal Stem Cells Using Chemically-Defined Serum-Free Media

Lee, Myung-Suk,Youn, Christine,Kim, Jeong Hyun,Park, Byoung Jun,Ahn, Jongchan,Hong, Sungyoul,Kim, Young-Deug,Shin, Young Kee,Park, Sang Gyu MDPI AG 2017 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.18 No.8

<P>The multipotency and anti-inflammatory effects of mesenchymal stem cells (MSCs) make them attractive for cell therapy in regenerative medicine. A large number of MSCs is required for efficient therapy owing to the low homing efficiency of MSCs to target sites. Furthermore, owing to limitations in obtaining sufficient amounts of MSCs, in vitro expansion of MSCs that preserves their differentiation and proliferative potential is essential. The animal factor included in culture media also limits clinical application. In this study, adipose-derived MSCs showed a significantly higher proliferation rate in STK2, a chemically-defined medium, than in DMEM/FBS. The expression of MSC surface markers was increased in the culture using STK2 compared to that using DMEM/FBS. Tri-lineage differentiation analyses showed that MSCs cultured in STK2 were superior to those cultured in DMEM/FBS. In addition, MSCs cultured in STK2 showed a reduced senescence rate, small and homogenous cell size, and were more genetically stable compared to those cultured in DMEM/FBS. Furthermore, secretome analysis showed that the expression of factors related to proliferation/migration, anti-inflammation, and differentiation were increased in STK2 culture medium compared to DMEM/FBS. Taken together, these results suggest that culture using STK2 medium offers many advantages through which it is possible to obtain safer, superior, and larger numbers of MSCs.</P>

Beef from the United States: Is It Safe?

김근수,김태수,최한별,Christine Ahn,Christopher C. Lee 대한의학회 2016 Journal of Korean medical science Vol.31 No.7

자기애적 웅대성 및 자기애적 취약성이 공격성에 미치는 영향

이기은(Kieun Lee),안명희(Christine Myunghee Ahn) 학습자중심교과교육학회 2024 학습자중심교과교육연구 Vol.24 No.8

목적 본 연구는 자기애적 웅대성과 자기애적 취약성이 공격성에 미치는 영향을 확인하고 그 과정에서 시기심과 수치심의 매개 효과를 탐색하고자 하였다. 방법 국내 만 20세 ~ 35세 미혼 남녀를 대상으로 병리적 자기애, 시기심, 수치심 경험, 공격성 척도로 구성된 자기보고 설문 양식을 이용하여 온라인으로 총 231명의 자료를 수집하였으며 SPSS 22.0과 Mplus ver. 7를 사용하여 분석하였다. 결과 첫째, 자기애적 웅대성과 자기애적 취약성은 시기심, 수치심, 공격성과 유의한 정적 상관을 보였다. 둘째, 자기애적 취약성이 시기심, 수치심, 공격성에 유의한 정적 영향을 미쳤다. 셋째, 자기애적 취약성이 시기심을 부분적으로 매개하여 공격성에 정적 영향을 미치는 경로를 확인하였다. 결론 본 연구는 자기애적 취약성이 공격성에 미치는 영향을 확인하고 시기심의 중요성을 밝혀, 상담 및 치료적 개입에 유용한 정보를 제공하였다. Objectives The purpose of this study is to investigate the influence of envy and shame in the relationship between narcissistic grandiosity and narcissistic vulnerability which are individual personality characteristics and aggression which can cause problems in interpersonal relationships using a structural equation model. Methods A total of 231 data were collected online using a self-report questionnaire form consisting of pathological narcissism, envy, shame experience, and aggression measures for unmarried men and women aged 20 to 35 in Korea, and analyzed using SPSS 22.0 and Mplus ver. 7. Results First, both narcissistic grandiosity and narcissistic vulnerability had significant positive correlations with envy, shame, and aggression. Second, narcissistic vulnerability had a significant positive effect on envy, shame, and aggression. Third, it was confirmed that narcissistic vulnerability had a positive influence on aggression, partially mediated by envy. Conclusions This study empirically investigated the impact of pathological narcissism, particularly narcissistic vulnerability on aggression and highlighted the importance of envy, providing useful information for counseling and therapeutic interventions.

Antifungal effects of synthetic human β-defensin 3-C15 peptide

Lim, Sang-Min,Ahn, Ki-Bum,Kim, Christine,Kum, Jong-Won,Perinpanayagam, Hiran,Gu, Yu,Yoo, Yeon-Jee,Chang, Seok Woo,Han, Seung Hyun,Shon, Won-Jun,Lee, Woocheol,Baek, Seung-Ho,Zhu, Qiang,Kum, Kee-Yeon The Korean Academy of Conservative Dentistry 2016 Restorative Dentistry & Endodontics Vol.41 No.2

Objectives: The purpose of this ex vivo study was to compare the antifungal activity of a synthetic peptide consisting of 15 amino acids at the C-terminus of human ${\beta}$-defensin 3 (HBD3-C15) with calcium hydroxide (CH) and Nystatin (Nys) against Candida albicans (C. albicans) biofilm. Materials and Methods: C. albicans were grown on cover glass bottom dishes or human dentin disks for 48 hr, and then treated with HBD3-C15 (0, 12.5, 25, 50, 100, 150, 200, and $300{\mu}g/mL$), CH ($100{\mu}g/mL$), and Nys ($20{\mu}g/mL$) for 7 days at $37^{\circ}C$. On cover glass, live and dead cells in the biomass were measured by the FilmTracer Biofilm viability assay, and observed by confocal laser scanning microscopy (CLSM). On dentin, normal, diminished and ruptured cells were observed by field-emission scanning electron microscopy (FE-SEM). The results were subjected to a two-tailed t-test, a one way analysis variance and a post hoc test at a significance level of p = 0.05. Results: C. albicans survival on dentin was inhibited by HBD3-C15 in a dose-dependent manner. There were fewer aggregations of C. albicans in the groups of Nys and HBD3-C15 (${\geq}100{\mu}g/mL$). CLSM showed C. albicans survival was reduced by HBD3-C15 in a dose dependent manner. Nys and HBD3-C15 (${\geq}100{\mu}g/mL$) showed significant fungicidal activity compared to CH group (p < 0.05). Conclusions: Synthetic HBD3-C15 peptide (${\geq}100{\mu}g/mL$) and Nys exhibited significantly higher antifungal activity than CH against C. albicans by inhibiting cell survival and biofilm.

인간이해 : 불안정 성인애착이 거절민감성에 미치는 영향: 외로움과 수치심의 매개효과

황지선 ( Ji Sun Hwang ),안명희 ( Myung Hee Christine Ahn ) 서강대학교 학생생활상담연구소 2015 人間理解 Vol.36 No.1

본 연구에서는 거절민감성의 원인요인으로 불안정 성인애착을 지목하고 이들 사이의 관계에 대인관계적 맥락에서 경험하는 대표적 부적 정서인 외로움과 수치심의 매개효과를 알아보고자 하였다. 이를 위해 다수의 대학생을 포함한 20-30대 초기 성인기 남, 여 295명을 대상으로 불안정 성인애착의 두 차원인 불안 애착과 회피 애착이 거절민감성에 미치는 영향을 외로움과 수치심이 각각 매개하는 경로구조모형을 검증하였다. 본 연구결과 첫째, 불안 애착과 회피 애착은 외로움, 수치심, 거절민감성과 유의미한 정적상관을 보였다. 둘째, 불안 애착은 외로움, 수치심과 거절민감성에 유의미한 영향을 미쳤다. 셋째, 회피 애착은 외로움을, 수치심은 거절민감성을 가중시켰다. 마지막으로, 불안 애착은 수치심을 부분매개로 거절민감성에 유의미한 영향을 미쳤다. 본 연구결과는 친밀한 대인관계를 형성하는데 어려움을 경험하고 부정적 사회적정서에 민감한 불안 애착을 보이는 내담자의 거절민감성을 감소하기 위해서는 외로움과 수치심에 개입할 필요를 시사한다. 본 연구의 의의 및 제한점, 그리고 후속연구를 위한 제언을 논의에 포함하였다. This study investigated the effect of insecure adult attachment on rejection sensitivity and the mediating role of loneliness and shame. A structural equation modeling was used to examine the pathway of influence among insecure adult attachment, in terms of attachment anxiety and attachment avoidance, loneliness, shame, and rejection sensitivity. Data from self-report questionnaires based on a sample of 295 adults in their early twenties to thirties including many college students were analyzed using the Mplus 4.21. Findings revealed that attachment anxiety significantly influenced loneliness, shame, and rejection sensitivity. The eff?ect of attachment anxiety on rejection sensitivity was partially mediated by shame. Attachment avoidance significantly influenced loneliness. The eff?ect of attachment avoidance on shame or rejection sensitivity, however, was not significant. These results indicated that there are separate pathways of influence among attachment anxiety and attachment avoidance, loneliness, shame and rejection sensitivity. The current findings extend the literature regarding insecure adult attachment as an important risk factor for rejection-sensitivity. Strengths and limitations of the present study and suggestions for future research are discussed. Counseling implications for clients with rejection sensitivity, particularly college students with attachment anxiety and negative social emotions such as lonliness and shame are included in the discussion.