Prognostic Implication of Right Ventricle Parameters Measured on Preoperative Cardiac MRI in Patients with Functional Tricuspid Regurgitation

Ahn Yura,Koo Hyun Jung,Kang Joon-Won,Choi Won Jin,Kim Dae-Hee,Song Jong-Min,Kang Duk-Hyun,Song Jae-Kwan,Kim Joon Bum,Jung Sung-Ho,Choo Suk Jung,Chung Cheol Hyun,Lee Jae Won,Yang Dong Hyun 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.8

Objective: To investigate the prognostic value of preoperative cardiac magnetic resonance imaging (MRI) for long-term major adverse cardiac and cerebrovascular events (MACCEs) in patients undergoing tricuspid valve (TV) surgery for functional tricuspid regurgitation (TR). Materials and Methods: The preoperative cardiac MR images, New York Heart Association functional class, comorbidities, and clinical events of 78 patients (median [interquartile range], 59 [51–66.3] years, 28.2% male) who underwent TV surgery for functional TR were comprehensively reviewed. Cox proportional hazards analyses were performed to assess the associations of clinical and imaging parameters with MACCEs and all-cause mortality. Results: For the median follow-up duration of 5.4 years (interquartile range, 1.2–6.6), MACCEs and all-cause mortality were 51.3% and 23.1%, respectively. The right ventricular (RV) end-systolic volume index (ESVI) and the systolic RV mass index (RVMI) were higher in patients with MACCEs than those without them (77 vs. 68 mL/m2, p = 0.048; 23.5 vs. 18.0%, p = 0.011, respectively). A high RV ESVI was associated with all-cause mortality (hazard ratio [HR] per value of 10 higher ESVI = 1.10, p = 0.03). A high RVMI was also associated with all-cause mortality (HR per increase of 5 mL/m2 RVMI = 1.75, p < 0.001). After adjusting for age and sex, only RVMI remained a significant predictor of MACCEs and all-cause mortality (p < 0.05 for both). After adjusting for multiple clinical variables, RVMI remained significantly associated with all-cause mortality (p = 0.005). Conclusion: RVMI measured on preoperative cardiac MRI was an independent predictor of long-term outcomes in patients who underwent TV surgery for functional TR.

Contributions of Overseas R&D Subsidiaries on Headquarters Innovation Performance: The Moderating Roles of Social Embeddedness and Knowledge Digestibility

Yura Jung(정유라),Chul Lee(이철),Jina Kang(강진아) 연세대학교 경영연구소 2020 연세경영연구 Vol.57 No.2

다국적 기업의 해외 연구개발 지사는 본사에 암묵지적이고 사회적 맥락에 대한 이해에 기반한 지식을 제공함으로써 본사의 효율적인 현지국 지식 습득과 학습에 기여한다. 본 연구는 어떻게 해외 연구개발 지사가 본사로 하여금 해당국의 지역적인 지식을 효율적으로 소싱하고 그로부터 학습하게 도와주는지를 밝히고자 한다. 연구는 또한 현지국의 기업들과 제휴를 맺음으로써 형성되는 해외 연구개발지사의 외부적 배태성이 이후에 본사의 해외지식 습득과 활용에 미치는 영향에 미치는 효과를 규명한다. 뿐만 아니라, 다국적 기업본사가 해외 연구개발지사에 비하여 지식 소화성을 갖추고 있는 것이 본사의 해당국 지식습득과 학습을 용이하게 하는 해외 연구개발 지사의 역할을 더욱 증폭시켜주는 조건임을 제시한다. 본 연구는 2008년 Fortune 500 기업 리스트에 속하는 162개의 다국적 기업들의 해외 연구개발 지사의 지리적 분포에 관한 데이터와 각각의 다국적 기업의 특허 데이터, 제휴 데이터 및 재무 데이터에 기반하여 정립한 가설을 검증하였다. 결과를 통해 다국적 기업의 본사가 해외 연구개발 지사가 지식이 풍부한 해당국에 존재함으로써 이후의 해당국 지식 습득과 학습에 관련한 일련의 활동에 있어 혜택을 볼 수 있음을 확인하였다. 또한, 결과는 본사가 지식 소화성을 갖추는 것이 이후 본사의 이후 혁신 성과에 해당국가의 연구개발지사가 기여하게 되는 바를 더욱 증폭시킴을 확인하였다. Overseas R&D subsidiaries contribute to the cross-border knowledge sourcing of multinational corporation (MNC) headquarters by providing tacit and context-specific knowledge and reducing the search costs borne by the headquarters. This study examines how overseas R&D subsidiaries allow their headquarters to source local knowledge from the host country in an efficient way. The study also investigates the effect on overseas knowledge sourcing which derives from the external embeddedness of an overseas R&D subsidiary in the local network of the host country upon experiencing the alliance with local entities. In addition, the degree of knowledge digestibility that each headquarters retains as a condition by which host country knowledge sourcing of headquarters can be effectively facilitated by the host country R&D subsidiary is also investigated. The study tests the hypotheses established with the data of geographical distribution of overseas R&D subsidiaries of 162 multinationals which were included on the Fortune 500 MNC list in the year 2008 and the patent data of each firm along with the alliance and financial data. The study provides empirical evidence that the headquarters can benefit from the existence of a R&D subsidiary when it exists in a host country with abundant knowledge. Moreover, the findings suggest that the headquarters having a degree of knowledge digestibility will reinforce the role of host country R&D subsidiary on host country knowledge acquisition, learning, and innovation of the headquarters.

CONTRIBUTIONS OF OVERSEAS R&D SUBSIDIARIES TO HEADQUARTER INNOVATION PERFORMANCE: THE MODERATING ROLE OF THE EXTERNAL EMBEDDEDNESS AND ABSORPTIVE CAPACITY

Yura Jung,Chul Lee,Jina Kang 글로벌지식마케팅경영학회 2017 Global Fashion Management Conference Vol.2017 No.07

Overseas R&D subsidiaries contribute to the cross -border knowledge sourcing of MNC headquarter by providing tacit and context specific knowledge and reducing the searching cost of the headquarter

Deep Learning Algorithm for Automated Segmentation and Volume Measurement of the Liver and Spleen Using Portal Venous Phase Computed Tomography Images

Ahn Yura,Yoon Jee Seok,Lee Seung Soo,Suk Heung-Il,Son Jung Hee,Sung Yu Sub,Lee Yedaun,Kang Bo-Kyeong,Kim Ho Sung 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.8

Objective: Measurement of the liver and spleen volumes has clinical implications. Although computed tomography (CT) volumetry is considered to be the most reliable noninvasive method for liver and spleen volume measurement, it has limited application in clinical practice due to its time-consuming segmentation process. We aimed to develop and validate a deep learning algorithm (DLA) for fully automated liver and spleen segmentation using portal venous phase CT images in various liver conditions. Materials and Methods: A DLA for liver and spleen segmentation was trained using a development dataset of portal venous CT images from 813 patients. Performance of the DLA was evaluated in two separate test datasets: dataset-1 which included 150 CT examinations in patients with various liver conditions (i.e., healthy liver, fatty liver, chronic liver disease, cirrhosis, and post-hepatectomy) and dataset-2 which included 50 pairs of CT examinations performed at ours and other institutions. The performance of the DLA was evaluated using the dice similarity score (DSS) for segmentation and Bland-Altman 95% limits of agreement (LOA) for measurement of the volumetric indices, which was compared with that of ground truth manual segmentation. Results: In test dataset-1, the DLA achieved a mean DSS of 0.973 and 0.974 for liver and spleen segmentation, respectively, with no significant difference in DSS across different liver conditions (p = 0.60 and 0.26 for the liver and spleen, respectively). For the measurement of volumetric indices, the Bland-Altman 95% LOA was -0.17 ± 3.07% for liver volume and -0.56 ± 3.78% for spleen volume. In test dataset-2, DLA performance using CT images obtained at outside institutions and our institution was comparable for liver (DSS, 0.982 vs. 0.983; p = 0.28) and spleen (DSS, 0.969 vs. 0.968; p = 0.41) segmentation. Conclusion: The DLA enabled highly accurate segmentation and volume measurement of the liver and spleen using portal venous phase CT images of patients with various liver conditions.

국내 영유아기 난민 아동의 발달에 관한 탐색 연구

강하라(Kang, Hara),김유라(Kim, Yura),노충래(Nho, Choong Rai) 한국아동복지학회 2020 한국아동복지학 Vol.69 No.1

국내에서 난민법이 시행된 2013년 이후 국내에 체류 중인 영유아기의 난민 아동의 수가 증가하고 있는 추세에 있다. 영유아기의 난민 아동들은 전생애적 발달의 기초를 마련하는 중요한 시기에 있음에도 불구하고 국내에 체류 중인 영유아기 난민 아동들에 관한 실증적 연구는 거의 전무한 상황이다. 이에 본 연구는 한국 영유아 발달검사(K-DST)를 활용하여 국내 영유아기 난민 아동들의 발달상태를 대 · 소근육 운동, 인지, 언어 및 사회성의 하위영역별로 탐색하고, 사회 · 환경적 요인에 따라 발달영역에 집단간 차이가 있는지를 파악하여 이들의 건강한 발달 및 적응을 돕기 위한 아동복지적 지원방안의 기초를 마련하는데 그 목적이 있다. 이를 위해 본 연구는 난민지원 NGO의 도움을 받아 4개월 이상 72개월 미만 영유아기에 해당하는 난민 영유아 101명을 임의표집 방법으로 모집하여, 이들의 보호자 혹은 부모를 대상으로 2017년 7월부터 10월까지 발달검사를 시행하였다. 그 결과 난민 영유아의 발달은 전체 영역에서 한국 영유아기의 또래 수준의 발달상태를 보였으나, 추적검사 요망 및 심화평가 권고에 해당하는 비율 역시 각 영역의 약 22∼47%를 차지하는 것으로 나타났다. 그리고 이들의 발달 하위영역에서는 대근육운동 발달영역이 가장 빠르고, 언어발달 영역이 가장 느린 것으로 나타났으며, 월 가구소득과 난민체류자격, 부모가 받은 사회활동지원 여부, 부모의 한국어 수준에 따라 영역별로 차이를 보이는 것으로 나타났다. 이러한 결과를 바탕으로 국내 체류 영유아기 난민 아동의 발달을 촉진하고 건강한 적응을 돕기 위한 아동복지적 지원방안을 논의하였다. Although the number of young refugee children in Korea has increased since the enactment of the Refugee Law in 2013, there is still a lack of empirical research on this population. Infancy and toddler stages are important periods, which may have persistent impacts throughout the child’s life course. This exploratory study examined the overall developmental milestones of young refugee children, ranging in age from 4 months to 71 months, in Korea by using the Korean Developmental Screening Test for Infants and Children (K-DST). A purposive sampling method was utilized to recruit 101 young refugee children, and only their parents or guardians were interviewed to examine the children’s overall developments, including in the following five subareas: gross- and fine- motor skills, cognition, language, and social development. Data were collected from July to October 2017 with help from non-profit organizations that have established working relationships with refugees. Results were as follows: First, the overall developmental milestones of young refugee children were average compared to their Korean counterparts, although 22 to 47 percent of them showed “need monitoring” or “need in-depth follow-up.” As for the subareas, young refugee children showed a high level of gross-motor skills and a low level of language development. When group differences were tested according to socio- and refugee-related variables, there were group differences depending on household income, refugee status, parental involvement in social activities, and parental Korean language skills. Based on the results, we discussed practice and policy implications for child welfare to ensure children’s healthy development.

행동변화를 위한 펀 디자인(Fun Design) 전략

김유라(Yura Kim),이선민(Sunmin Lee),강부경(Bukyung Kang),윤재영(Jae Young Yun) 한국HCI학회 2017 한국HCI학회 학술대회 Vol.2017 No.2

본 연구는 ‘재미(Fun)’를 통해 사용자의 긍정적 행동변화를 유도하는 ‘펀 디자인’의 전략들을 분석한다. 펀 디자인 전략에는 크게 트리거, 피드백, 소셜 인터랙션이 있다. 트리거는 매체의 유형과 시청각적 요소들로 이루어져 있으며, 피드백은 비물질적, 물질적 피드백으로 구분된다. 연구 결과 트리거는 사용자의 호기심을 유발하여 참여를 이끌어 내는 역할을 하였고, 피드백은 행동에 대한 보상과 지속적인 행동을 유도하는 역할을 하는 것으로 나타났다. 소셜 인터랙션 전략은 펀 디자인이 감정적 맥락에서의 재미 뿐 아니라 사회적인 맥락 안에서 사용자 간의 소통을 형성한다.

오일질량분률 측정용 정전용량센서 모듈

김유라(Yura Kim),나경환(Kyung Hwan Na),강현성(Hyun Sung Kang),임시형(Si-Hyung Lim) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

Determination of nanomolar levels of reactive oxygen species in microorganisms and aquatic environments using a single nanoparticle-based optical sensor

Kim, Yura,Kim, Youngho,Choi, Jinhee,Kang, Taewook,Choi, Inhee Elsevier 2017 Analytica chimica acta Vol.967 No.-

<P><B>Abstract</B></P> <P>Reactive oxygen species (ROS) are strong oxidants, and have attracted considerable attention in both biological and environmental fields. Although various methods for ROS detection, including optical and electrochemical techniques, have been developed, they still face challenging issues in terms of poor sensitivity, reproducibility, stability, and <I>in vivo</I> applicability. Here, we present a sensitive and selective optical sensor for ROS detection, based on single plasmonic nanoprobes and redox-active cytochrome <I>c</I> (Cyt <I>c</I>)-mediated plasmon resonance energy transfer. By measuring the spectral changes of plasmonic nanoprobes, derived from the unique molecular absorption of Cyt <I>c</I> in accordance with the redox state, calibration curves for H<SUB>2</SUB>O<SUB>2</SUB>, a representative ROS, in various media were obtained over a wide concentration range from 100 mM to 1 nM. Limit of detection and limit of quantification in accordance with the used medium were determined from 8.3 to 12.8 nM and from 27.6 to 42.7 nM, respectively. Selectivity coefficients for major interfering solutes were much lower than 0.1 indicating a good selectivity for ROS. From the dynamic spectral changes, we sensitively monitored ROS generated in <I>Caenorhabditis elegans</I> (<I>C. elegans</I>) exposed to graphene oxide. Based on the calibration curves, we also determined ROS levels in various aquatic environments, such as river streams and a small pond, as a way of environmental monitoring. We believe that our approach could provide an avenue for achieving dynamic and sensitive monitoring of ROS in toxicological, biological, and environmental fields in the future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Single nanoparticle-based optical sensor for monitoring reactive oxygen species (ROS). </LI> <LI> More sensitive monitoring and wider detection range than commercially available method. </LI> <LI> Limit of detection and quantification were determined from 8.3 to 12.8 nM and from 27.6 to 42.7 nM, respectively. </LI> <LI> Selectivity coefficients for major interfering solutes were much lower than 0.1. </LI> <LI> Determination of nanomolar level ROS in biological and environmental samples. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Tricuspid Valve Imaging and Right Ventricular Function Analysis Using Cardiac CT and MRI

Ahn Yura,Koo Hyun Jung,Kang Joon-Won,Yang Dong Hyun 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.12

Cardiac computed tomography (CT) and cardiac magnetic resonance imaging (CMR) can reveal the detailed anatomy and function of the tricuspid valve and right ventricle (RV). Quantification of tricuspid regurgitation (TR) and analysis of RV function have prognostic implications. With the recently available transcatheter treatment options for diseases of the tricuspid valve, evaluation of the tricuspid valve using CT and CMR has become important in terms of patient selection and procedural guidance. Moreover, CT enables post-procedural investigation of the causes of valve dysfunction, such as pannus or thrombus. This review describes the anatomy of the tricuspid valve and CT and CMR imaging protocols for right heart evaluation, including RV function and TR analyses. We also demonstrate the pre-procedural planning for transcatheter treatment of TR and imaging of postoperative complications using CT.

Investigations of Graphene Grown on Copper Substrates

Sangmo Cho,Yura Kang,Jungtae Nam,Keun Soo Kim,Suklyun Hong 한국진공학회 2014 한국진공학회 학술발표회초록집 Vol.2014 No.2