66 results on '"Semin Park"'
Search Results
2. Intra-Individual Conflict and Task Performance in a Multiteam Context: Examining the Structural Elements of Conflict Experience
- Author
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Semin Park, Margaret M. Luciano, John E. Mathieu, and Virgil W. Fenters
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Management of Technology and Innovation ,Strategy and Management ,Business and International Management ,General Business, Management and Accounting - Published
- 2023
3. Indexing dynamic collective constructs using computer-aided text analysis: Construct validity evidence and illustrations featuring team processes
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John E. Mathieu, Elizabeth A. Klock, Semin Park, Margaret M. Luciano, Mikhail A. Wolfson, Scott I. Tannenbaum, Wendy L. Bedwell-Torres, and P. Scott Ramsay
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Subject-matter expert ,Convergent validity ,Computers ,Behaviorally anchored rating scales ,Content validity ,Humans ,Construct validity ,Test validity ,Construct (philosophy) ,Psychology ,Data science ,Applied Psychology ,Unobtrusive research - Abstract
Organizational processes have been widely recognized as both multilevel and dynamic, yet traditional methods of measurements limit our ability to model and understand such phenomena. Featuring a popular model of team processes advanced by Marks et al. (2001), we illustrate a method to use individuals' communications as construct valid unobtrusive measures of collective constructs occurring over time. Thus, the purpose of this investigation is to develop computer-aided text analysis (CATA) techniques that can score members' communications into valid team process measures. We apply a deductive content validity-based method to construct CATA dictionaries for Marks et al.'s dimensions. We then demonstrate their convergent validity with subject matter experts' (SMEs) hand-coded team communications and different SMEs' behaviorally anchored rating scales based on video recordings of team interactions, using multitrait-multimethod analyses in two samples. Using a third sample of paramedics performing a high-fidelity mass casualty incident exercise, we further demonstrate the convergent validity of the CATA and SME scorings of communications. We then model the relationships among processes across episodes using all three samples. Next, we test criterion-related validity using a longitudinal dual-discontinuous change growth modeling design featuring the paramedic CATA-scored team processes as related to a dynamic performance criterion. Finally, we integrate behavioral data from wearable sensor badges to illustrate how CATA can be scored at the individual level and then leveraged to model dynamic networks of team interactions. Implications, limitations, directions for the future research, and guidelines for the application of these techniques to other collective constructs are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
- Published
- 2022
4. The Double-Edged Sword of Leadership Task Transitions in Emergency Response Multiteam Systems
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Semin Park, Margaret M. Luciano, Scott I. Tannenbaum, Virgil Fenters, and Amy L. Bartels
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Emergency response ,Organizational behavior ,Management of Technology and Innovation ,Strategy and Management ,Business and International Management ,SWORD ,Topic areas ,Psychology ,General Business, Management and Accounting ,Cognitive psychology ,Task (project management) - Abstract
Multiteam systems (MTSs) operating in complex and dynamic environments often have a formal hierarchical leadership structure. However, it is unclear whether individuals should stick exclusively to ...
- Published
- 2021
5. Configurational Research in Teams
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Amanda Ferguson, Li Lu, Nathan Black, Kyle J. Emich, Elizabeth Klock, Thomas Alexander O'Neill, Semin Park, David Bergman, John Mathieu, Randall S Peterson, Stephen Reid, Greg L. Stewart, and Scott I Tannenbaum
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General Medicine - Published
- 2022
6. Thermo-mechanical fatigue induced unexpected strain hardening of Cu clip wiring on transfer-mold type EV power modules
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Dongjin Kim, Seungjun Noh, Semin Park, and Min-Su Kim
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Mechanics of Materials ,Mechanical Engineering ,Modeling and Simulation ,General Materials Science ,Industrial and Manufacturing Engineering - Published
- 2023
7. Regulation of Cellular Ribonucleoprotein Granules: From Assembly to Degradation via Post-translational Modification
- Author
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Pureum Jeon, Hyun-Ji Ham, Semin Park, and Jin-A Lee
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Ribonucleoproteins ,RNA-Binding Proteins ,General Medicine ,Cytoplasmic Granules ,Protein Processing, Post-Translational ,Cytoplasmic Ribonucleoprotein Granules - Abstract
Cells possess membraneless ribonucleoprotein (RNP) granules, including stress granules, processing bodies, Cajal bodies, or paraspeckles, that play physiological or pathological roles. RNP granules contain RNA and numerous RNA-binding proteins, transiently formed through the liquid–liquid phase separation. The assembly or disassembly of numerous RNP granules is strongly controlled to maintain their homeostasis and perform their cellular functions properly. Normal RNA granules are reversibly assembled, whereas abnormal RNP granules accumulate and associate with various neurodegenerative diseases. This review summarizes current studies on the physiological or pathological roles of post-translational modifications of various cellular RNP granules and discusses the therapeutic methods in curing diseases related to abnormal RNP granules by autophagy.
- Published
- 2022
8. Ultra-thin Fe–Si alloy sheet with excellent high frequency magnetic properties fabricated by partial decarburization combined with multi-stage cold rolling
- Author
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Jungkyun Na, Hyun-seok Ko, Yangmo Koo, and Semin Park
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Mechanics of Materials ,Mechanical Engineering ,Metals and Alloys ,General Materials Science ,Condensed Matter Physics - Published
- 2023
9. A Network Conceptualization of Team Conflict
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Semin Park, John E. Mathieu, and Travis J. Grosser
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Conceptualization ,Strategy and Management ,05 social sciences ,Applied psychology ,050109 social psychology ,Interpersonal communication ,General Business, Management and Accounting ,Work (electrical) ,Management of Technology and Innovation ,0502 economics and business ,Team conflict ,0501 psychology and cognitive sciences ,Work teams ,Psychology ,Social psychology ,050203 business & management - Abstract
Previous research has highlighted how interpersonal- and task-based conflicts can impact work team effectiveness. The majority of such work, however, has implicitly treated both types of conflict a...
- Published
- 2020
10. Understanding Work Teams From a Network Perspective: A Review and Future Research Directions
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Semin Park, Adam Roebuck, Travis J. Grosser, and John E. Mathieu
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Knowledge management ,business.industry ,Strategy and Management ,Perspective (graphical) ,Sociology ,Work teams ,business ,Finance - Abstract
As social network theory and methodology advance, scholars in multiple fields have increasingly become interested in examining work teams using network perspectives. Social networks not only enabled work team researchers to theorize about interdependencies and the dynamic interplay of team components (i.e., individuals, dyads, and whole teams) but also provided a methodological tool kit with which to operationalize and test hypotheses about such interdependencies. To this end, the purpose of this article is to conduct an integrative review of organizational teams research that has adopted a social network perspective to highlight what is known and what remains to be addressed. We then outline an agenda for future research that introduces three promising areas to guide researchers to move the field forward. We conclude that a more thorough integration of the networks and teams literatures offer great promise for advancing both our science and practice.
- Published
- 2020
11. DBC-Packaged Inverter Power Module for Integrated Motor-Inverter Design Used in 48 V Mild Hybrid Starter-Generator (MHSG) System
- Author
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Jangmuk Lim, Sang Won Yoon, Semin Park, Hobeom Han, Jaejin Jeon, Min Ki Kim, and Jihwan Seong
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Wire bonding ,Materials science ,Computer Networks and Communications ,business.industry ,Transistor ,Electrical engineering ,Aerospace Engineering ,dBc ,020302 automobile design & engineering ,02 engineering and technology ,law.invention ,0203 mechanical engineering ,law ,Hybrid system ,Power module ,Automotive Engineering ,Parasitic element ,Inverter ,Electrical and Electronic Engineering ,business ,Voltage - Abstract
This paper presents an improved package design of an inverter power module specialized for the 48 V starter- generator used in 48 V mild hybrid vehicles. The inverter module, called the mild hybrid starter and generator (MHSG), is integrated with its motor for size/volume reduction. However, the integrated motor-inverter presents supplementary challenges, such as limited cooling capabilities, in addition to the challenges resulting from the elevated voltage of 48 V of the mild hybrid systems. The proposed MHSG power module addresses these challenges. Parallel-connected metal-oxide-semiconductor field-effect transistor (MOSFET) dies were solder-bonded onto a direct bonded copper (DBC) substrate, and three DBC substrates (providing six legs) were assembled in a custom housing mounted on a forced air cooler. Shunt resistors and surface-mount device components were also soldered onto the DBC substrates. For improved stability and balance, ribbon bonding was used instead of wire bonding, the module components were repositioned, and DBC patterns were adjusted. The aforementioned approaches minimized the parasitic inductance, unbalanced/concentrated current density, and maximum temperature of the 48 V MHSG inverter module. The proposed module was validated through multiphysics finite-element method (FEM) simulations, manufactured prototypes, and experiments, all of which confirmed that the proposed module exhibits the electrical/thermal characteristics required for 48 V integrated MHSG systems.
- Published
- 2019
12. Power cycling tests under driving ΔTj = 125 °C on the Cu clip bonded EV power module
- Author
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Dongjin Kim, Byeongsoo Lee, Tae-Ik Lee, Seungjun Noh, Chanyang Choe, Semin Park, and Min-Su Kim
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Electrical and Electronic Engineering ,Safety, Risk, Reliability and Quality ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2022
13. Mitigating Violence Against First Responder Teams: Results and Ideas From the Hackmanathon
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Regan M. Murray, Kaitlin Fosler, Alexa Harris, Poppy Lauretta McLeod, Lily Cushenbery, Lindsay Elizabeth Larson, Molly P. Kilcullen, Semin Park, Tomohiro Ioku, Cynthia K. Maupin, Michael A. Rosen, Joseph A. Allen, Josette M.P. Gevers, Trevor Fry, Samantha Perry, Jennifer A. Taylor, Human Performance Management, and EAISI Foundational
- Subjects
safety ,rechtvaardigheid en sterke instellingen ,SDG 16 - Peace ,Social Psychology ,Situation awareness ,SDG 16 – Vrede ,050109 social psychology ,Patient care ,First responder ,0502 economics and business ,medicine ,0501 psychology and cognitive sciences ,Applied Psychology ,Service (business) ,SDG 16 - Peace, Justice and Strong Institutions ,05 social sciences ,Front line ,medicine.disease ,Justice and Strong Institutions ,situational awareness ,multiteam systems ,Emergency response ,emergency response ,hackathon ,Medical emergency ,Psychology ,050203 business & management - Abstract
First responders are on the front line of patient care and service, but research has shown that they are also on the front line of exposure to violence. Currently, there is a lack of evidence-based interventions that prepare first responders to handle violence on the job. With the increase in emergency medical services (EMS) call volume and reports of at least 57% of the EMS responders having experienced workplace violence, there is a need to develop scientifically systematic solutions to improve emergency responder safety. Using an adapted version of the hackathon method, academic scholars and practitioner conference attendees at the Interdisciplinary Network for Group Research (INGRoup) Conference were deployed into three multidisciplinary teams to analyze the issue and develop specific solutions. These solutions offer unique interventions to improve first responder safety.
- Published
- 2019
14. Multiphysics Simulation Analysis and Design of Integrated Inverter Power Module for Electric Compressor Used in 48-V Mild Hybrid Vehicles
- Author
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Min Ki Kim, Jaejin Jeon, Semin Park, Jihwan Seong, Jangmuk Lim, Sang Won Yoon, and Hobeom Han
- Subjects
Computer science ,Multiphysics ,020208 electrical & electronic engineering ,Energy Engineering and Power Technology ,Hardware_PERFORMANCEANDRELIABILITY ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Automotive engineering ,Inductance ,Modeling and simulation ,Power module ,Hardware_INTEGRATEDCIRCUITS ,0202 electrical engineering, electronic engineering, information engineering ,Overshoot (signal) ,Inverter ,Electronics ,Electrical and Electronic Engineering ,0210 nano-technology ,Voltage - Abstract
This paper presents designs, multiphysics finite-element method (FEM) and circuit simulations, and experimental validations of a three-phase inverter power module for an electric compressor (e-Compressor) used in 48-V mild hybrid vehicles. The inverter module is integrated with its motor and scroll. The integration and e-Compressor operation situations raise sequential challenges in the module design and analysis. Thus, the e-Compressor module employs a direct bonded copper (DBC) substrate on which MOSFET dies, shunt resistors, and other electronics are soldered. Multiphysics FEM and circuit simulations are conducted to analyze (and minimize) the parasitic and loop inductances, current concentration, and temperature elevation of the design. The modeling and simulation processes are customized to represent the integrated DBC-based e-Compressor module, including the determination of loop inductance and overshoot voltage by considering systemic current conduction and reasonable simplification of cooling fluid effects. The simulation process and module performances are validated by experiments. The designed e-Compressor inverter module is improved to fully satisfy all the required specifications. Moreover, an excellent agreement between the simulation and the experimental results is confirmed, demonstrating the similar reductions of: 1) loop inductances simulated by FEM (~57%); 2) circuit-simulated overshoot voltages (~47%); and 3) experimentally measured overshoot voltages (~53%).
- Published
- 2019
15. Network Thinking in Teams Research
- Author
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Travis J. Grosser, John E. Mathieu, Semin Park, and Adam Roebuck
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Psychology - Published
- 2019
16. Key Issues and Implications of the Leniency Policy
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Semin Park
- Subjects
Damages ,Cartel ,Business ,Key issues ,Law and economics - Published
- 2018
17. The evolution of work team research since Hawthorne
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John E. Mathieu, Semin Park, and Mikhail A. Wolfson
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Teamwork ,Research ,media_common.quotation_subject ,Hawthorne effect ,05 social sciences ,Historical Article ,Team effectiveness ,050109 social psychology ,General Medicine ,PsycINFO ,History, 20th Century ,History, 21st Century ,Psychology, Social ,Group Processes ,Work (electrical) ,0502 economics and business ,Humans ,0501 psychology and cognitive sciences ,Engineering ethics ,Cooperative Behavior ,Working group ,Discipline ,050203 business & management ,General Psychology ,media_common - Abstract
Since the Hawthorne studies of the 1920s and 1930s, there has been tremendous progress in the science and the practice of work group effectiveness. We chronicle the evolution of 3 schools of thought concerning work groups that spawned about the time of those studies. We highlight the different emphases of each perspective and how they eventually merged into an integrated view of teamwork. We also illustrate the disciplinary ebbs and flows of work group research over the past quarter century and how many different scholars from diverse institutions are currently contributing to the literature. We highlight the progress that has been made both in terms of scholarly insights and practical advances. We argue that the popular Input-Process-Outcome framework has facilitated progress in the field but has also become a limiting factor. We conclude that future advances will be associated with: (a) the advent of new theories, methodologies, and tools for modeling dynamic team properties; (b) a greater appreciation for, and sophisticated conceptions of, team task environments; and (c) conceptions of teams as entities in multilevel environments. (PsycINFO Database Record
- Published
- 2018
18. A Study on the Introduction and the Improvement direction of Heir’s Limited Liability System
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Semin Park
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Limited liability ,Political science ,Law and economics - Published
- 2018
19. A Study on Heir’s Limited Liability and the Inheritance
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Semin Park
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Inheritance (object-oriented programming) ,Limited liability ,Business ,Genealogy - Published
- 2017
20. The Ʃ3 twin dependence of thermo-mechanical fatigue of a polycrystalline high-purity Cu film
- Author
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Seungjun Noh, Chanyang Choe, Sangmin Lee, Semin Park, Katsuaki Suganuma, Chuantong Chen, Seung-Joon Lee, and Dongjin Kim
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Diffraction ,Materials science ,Mechanical Engineering ,02 engineering and technology ,Electron ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Fracture (geology) ,General Materials Science ,Grain boundary ,Crystallite ,Composite material ,0210 nano-technology ,Grain structure ,Striation ,Thermo-mechanical fatigue - Abstract
This study conducts stress-controlled cyclic tension-tension tests from room temperature (RT) to 200 °C, at 50 °C intervals, on high-purity Cu films to comprehensively understand the temperature-dependent fatigue life and the related microstructural and fracture characteristics. As evidenced by the electron backscattering diffraction analysis, the Ʃ3 boundary fraction decreases and the low-angle grain boundary fraction increases as the temperature increases. The significant change in the grain structure at high temperatures leads to a reduced fatigue life. The fatigue striations are closely spaced at RT and the fracture surface develops into the typical fatigue striation and the void zones.
- Published
- 2021
21. The impact of individual conflict experiences on proximal task performance in a multi-team context
- Author
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Semin Park
- Subjects
Phenomenon ,Context (computing) ,General Medicine ,Psychology ,Cognitive psychology ,Task (project management) - Abstract
Conflict is a dynamic phenomenon that may manifest in different fashions over time. In understanding conflict in small groups and teams, however, much of our understanding is still limited around t...
- Published
- 2021
22. A New Way for Teams to Come Together: Unpacking Process Gains Through Team Composition
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Nathan Black, Semin Park, Jerry Guo, Erin Fahrenkopf, Anita Williams Woolley, Greg L. Stewart, Jisoo Park, Jonathan Kush, Adam Roebuck, Ki-Won Haan, Linda Argote, Murray R. Barrick, John E. Mathieu, and Stephen Reid
- Subjects
Unpacking ,Team composition ,Process management ,Process (engineering) ,General Medicine ,Business ,Human capital - Abstract
Modern organizations are complex and often require the use of teams to accomplish tasks. But to accomplish such tasks requires the effective assembly of human capital. As such, scholars and practit...
- Published
- 2021
23. A Fitting Approach to Construct and Measurement Alignment
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Semin Park, John E. Mathieu, Scott I. Tannenbaum, and Margaret M. Luciano
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Change over time ,Computer science ,business.industry ,Management science ,Strategy and Management ,05 social sciences ,Big data ,General Decision Sciences ,Construct validity ,050109 social psychology ,Data science ,Dynamics (music) ,Management of Technology and Innovation ,0502 economics and business ,0501 psychology and cognitive sciences ,business ,Construct (philosophy) ,050203 business & management - Abstract
Many phenomena of interest to management and psychology scholars are dynamic and change over time. One of the primary impediments to the examination of dynamic phenomena has been challenges associated with collecting data at a sufficient frequency and duration to accurately model such changes. Emerging technologies that produce nearly continuous streams of big data offer great promise to address those challenges; however, they introduce new methodological challenges and construct validity concerns. We seek to integrate the emerging big data technologies into the existing repertoire of measurement techniques and advance an iterative process to enhance their measurement fit. First, we provide an overview of dynamic constructs and temporal frameworks, highlighting their measurement implications. Second, we discuss different data streams and feature emerging technologies that leverage big data as a means to index dynamic constructs. Third, we integrate the previous sections and advance an iterative approach to achieving measurement fit, highlighting factors that make some measurement choices more suitable and viable than others. In so doing, we hope to accelerate the advancement of dynamic theories and methods.
- Published
- 2017
24. A critical analysis on the contents of the insurer's duty to provide information etc in insurance contract law in Germany -Assuming the possibility of introduction of these duties to Korea
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Semin Park
- Subjects
Actuarial science ,Insurance policy ,media_common.quotation_subject ,General Medicine ,Business ,Duty ,media_common - Published
- 2017
25. A critical analysis on the Korean Fair Trade Commission' interpretation on the relationship between the financial supervisory authorities' administrative guidance and insurance companies' collaborative act
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Semin Park
- Subjects
Fair trade ,Actuarial science ,business.industry ,Administrative guidance ,Interpretation (philosophy) ,Accounting ,General Medicine ,Commission ,business - Published
- 2016
26. 유류분제도의 현대적 의의
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Semin Park
- Subjects
Successor cardinal ,History ,Donation ,Law - Published
- 2016
27. Transactive Memory Systems: A Dynamic, Compilational Perspective
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John E. Mathieu, Adam Roebuck, Travis J. Grosser, and Semin Park
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Transactive memory ,Perspective (graphical) ,Cognition ,General Medicine ,Psychology ,Cognitive psychology - Abstract
Transactive memory systems (TMSs) are associated with positive team outcomes due to their ability to allow members to expeditiously draw on expert knowledge while reducing the cognitive burden acro...
- Published
- 2020
28. Integrated Motor-Inverter Power Module for Electric Compressor (E-Compressor) in 48V Mild Hybrid Vehicles
- Author
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Jaejin Jeon, Yucheol Park, Sang-Min Kim, Sang Won Yoon, Min Ki Kim, Taesuk Kwon, Hyunkyu Choi, Semin Park, Pilkyoung Oh, Jangmuk Lim, and Jihwan Seong
- Subjects
Air cooling ,Materials science ,020208 electrical & electronic engineering ,020302 automobile design & engineering ,Hardware_PERFORMANCEANDRELIABILITY ,02 engineering and technology ,Automotive engineering ,Reliability (semiconductor) ,0203 mechanical engineering ,Power module ,MOSFET ,Parasitic element ,Hardware_INTEGRATEDCIRCUITS ,0202 electrical engineering, electronic engineering, information engineering ,Inverter ,Gas compressor ,Voltage - Abstract
A three-leg MOSFET inverter power module is presented, which is designed to operate the electric compressor (e-Compressor) of 48V mild hybrid vehicles. The e-Compressor module is integrated with its motor. The motor-inverter integration and the voltage elevation to 48V have advantages over conventional 12V vehicle systems, but also enforce subsequent challenges in system assembly, electrical reliability, and thermal management. We tackle these challenges first by using MOSFET dies soldered on direct bond copper (DBC) substrates. The DBC-based module also incorporates high-power shunt resistors, SMD devices, air cooling, and ribbon bonding interconnections. Finite-element-method (FEM) simulations are tailored to represent practical e-Compressor operations. The simulations are conducted to minimize parasitic inductance/resistance, concentrated current density, and device temperatures. The designed e-Compressor module is manufactured and experimentally calibrated, notably decreasing stray inductance by ∼57% and consequently reducing overshoot voltage by ∼53%. It is confirmed that the module temperature is lower than the allowable MOSFET temperature.
- Published
- 2018
29. Heel crack propagation mechanism of cold-rolled Cu/Al clad ribbon bonding in harsh environment
- Author
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Shijo Nagao, Tohru Sugahara, Semin Park, and Katsuaki Suganuma
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Thermal shock ,Materials science ,Environmental tests ,Metallurgy ,Electroless nickel immersion gold ,Recrystallization (metallurgy) ,Fracture mechanics ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Ribbon ,Grain boundary ,Electrical and Electronic Engineering ,Electron backscatter diffraction - Abstract
A cold-rolled Cu/Al clad ribbon was bonded on an electroless nickel immersion gold (ENIG)-finished Cu substrate by ultrasonic bonding. The bonding samples were subjected to harsh conditions such as thermal exposure at 200 °C and thermal shock at −40/250 °C. The microstructural evolution and textural transitions in the Cu/Al clad ribbons were analyzed using electron backscatter diffraction to understand the heel crack propagation mechanism. The heel cracks were initiated at the edge of the Al layer between the bonded and non-bonded zones and were propagated along the coarsened grain boundaries deep into the cladded Cu layer. The continuous dynamic recrystallization (CDRX) transition phenomena around the heel cracks were scrutinized by electron backscatter pattern analysis to reveal the different microstructural and textural evolutions as a function of the ultrasonic bonding process at the bonded part and of lift-up at the non-bonded part. The heel cracks were occurred by grain coarsening due to CDRX within the Al layer during the environmental tests. The region of coarsened grains by CDRX was extended with increasing test periods. Especially in the thermal shock tests at −40/250 °C, severe grain coarsening was found involving significant transformation of sub-grains into grains by rapid CDRX development. Thus, heel crack propagation accelerated more during thermal shock cycles than during high-temperature storage.
- Published
- 2015
30. Development and validation of a high-performance liquid chromatography-tandem mass spectrometric method for simultaneous determination of bupropion, quetiapine and escitalopram in human plasma
- Author
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Gon Sup Kim, Young Ah Cho, H. A. El-Banna, Ahmet Hacimuftuoglu, A. M. Abd El-Aty, Jae-Han Shim, Boseok Cha, Chul-Soo Park, Eun Ae Yu, Yi Song, Semin Park, Sung-Joon Lee, Sung Chul Shin, and Jong Sung Jin
- Subjects
Pharmacology ,Bupropion ,Chromatography ,Tandem ,Chemistry ,Clinical Biochemistry ,Selected reaction monitoring ,Extraction (chemistry) ,Analytical chemistry ,General Medicine ,Biochemistry ,High-performance liquid chromatography ,Analytical Chemistry ,Human plasma ,Drug Discovery ,medicine ,Quetiapine ,Escitalopram ,Molecular Biology ,medicine.drug - Abstract
In the present study, an effective high performance liquid chromatography-tandem mass spectrometric (HPLC/ MS/MS) method was developed and validated to simultaneously determine bupropion (BUP), quetiapine (QUE) and escitalopram (ESC) in human plasma using carbidopa as the internal standard. Chromatographic separation was achieved on a Waters Sun Fire C18 column using reversed-phase chromatography. The MS/MS experiment was performed in positive ion multiple reaction monitoring mode to produce product ions of m/z 240.3 →184.2 for BUP, 384.2 →253.1 for QUE, 325.3 →109.3 for ESC and 227.2 →181.2 for the internal standard. The method showed good linearity (R 2 ≥0.997), precision (relative standard deviation ≤7.5%), satisfactory intra- and interday accuracy (88.4-113.0%) and acceptable extraction recov- ery (87.2-115.0%), matrix effect (84.5.5108.7%) and stability (92.3103.5%). The method was successfully applied to deter- mine the concentrations of BUP, QUE and ESC in human plasma samples. Copyright © 2014 John Wiley & Sons, Ltd.
- Published
- 2014
31. Flavonoid profiles of immature and mature fruit tissues ofCitrus grandisOsbeck (Dangyuja) and overall contribution to the antioxidant effect
- Author
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Jae Hoon Kim, Gon-Sup Kim, Semin Park, Jae-Han Shim, Soo-Jung Lee, Song Yi, Eun Ae Yu, Jong Sung Jin, Ji Eun Lee, A. M. Abd El-Aty, and Sung Chul Shin
- Subjects
Pharmacology ,chemistry.chemical_classification ,Neohesperidin ,Folk medicine ,Antioxidant ,Chromatography ,medicine.medical_treatment ,Flesh ,fungi ,Clinical Biochemistry ,Flavonoid ,food and beverages ,General Medicine ,Biochemistry ,Analytical Chemistry ,Citrus grandis ,chemistry.chemical_compound ,Horticulture ,chemistry ,Functional food ,Drug Discovery ,medicine ,Molecular Biology ,Naringin - Abstract
Citrus fruits are a valuable functional food and their peel is used in East Asian folk medicine. In this study, the polar components of the fruit tissues of Citrus grandis Osbeck were analyzed using high-performance liquid chromatography-tandem mass spectrometry and compared with reported data. Among the 13 characterized compounds, eight flavonoids and one coumarin were identified for the first time in fruit tissues. The total amount of the identified components was the largest for the immature fruit peel, followed by mature fruit peel, mature fruit flesh, and immature fruit flesh. Naringin (2) and neohesperidin (3) were particularly rich in all samples. The antioxidant activity of the flavonoids extracted from fruit tissues increased in a dose-dependent manner. The activity of the fruit peels was significantly higher than that of the fruit flesh. Copyright © 2014 John Wiley & Sons, Ltd.
- Published
- 2014
32. Variation in flavonoid levels in Citrus benikoji Hort. ex. Tan. infected by Colletotrichum gloeosporioides
- Author
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Hae Gyeong Kim, Ji Eun Lee, Sung Chul Shin, Gon-Sup Kim, Sung Woo Jeong, Jong Sung Jin, Semin Park, Moo Ryong Huh, Jung Han Lee, Youn-Sig Kwak, Yi Song, and Yun-Hi Kim
- Subjects
Citrus ,Flavonoid ,Defence mechanisms ,Fungus ,Biology ,Analytical Chemistry ,chemistry.chemical_compound ,Glucoside ,Colletotrichum gloeosporioides ,Botany ,Colletotrichum ,heterocyclic compounds ,Plant Diseases ,Flavonoids ,chemistry.chemical_classification ,Plant Extracts ,Inoculation ,Phytoalexin ,fungi ,food and beverages ,General Medicine ,biology.organism_classification ,Horticulture ,chemistry ,Fruit ,Postharvest ,Food Science - Abstract
Anthracnose caused by Colletotrichum gloeosporioides is one of the most serious postharvest diseases of citrus fruit. Fruit peels infected with C. gloeosporioides and the peels of healthy fruit were analysed for flavonoids, using high performance liquid chromatography–tandem mass spectroscopy, to evaluate variations in flavonoid levels in Citrus benikoji Hort. ex. Tan. Seventeen flavonoids were characterised from the fruit peels. The flavonoids were validated using structurally related standards and quantified. Among the 17 flavonoids, the concentration of component 3 was the highest and that of component 10 was the lowest. During 8 days after inoculation, the concentration of the seven flavonoids 1 – 3 , 5 , 6 , 13 , and 14 increased gradually up to day 8. Flavonoid 4 was detected from day 7. The seven minor flavonoid components, 8 – 12 , 15 , and 16 increased to day 5 and then decreased. However, flavonoids level variations were not significantly different from that of the non-infected fruits during the experimental period. The monitoring suggested that the constitutively formed seven polymethoxyflavones ( 8 – 12 , 15 , and 16 ) may act as phytoanticipins in the defence mechanism against the fungus, and that hespertin 7- O -glucoside ( 4 ), produced de novo on day 6 after infection, may function as a phytoalexin.
- Published
- 2014
33. ZAG Regulates the Skin Barrier and Immunity in Atopic Dermatitis
- Author
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Young Hwan Kim, Kyungho Park, Tae-Gyun Kim, Semin Park, Kyong Oh Shin, Seo Hyeong Kim, Kwang Hoon Lee, Jung U Shin, Ji Yeon Noh, B. Kim, and Ji Hye Kim
- Subjects
Keratinocytes ,0301 basic medicine ,Ceramide ,Injections, Intradermal ,Administration, Topical ,T-Lymphocytes ,Adipokine ,Dermatology ,ADAM17 Protein ,Filaggrin Proteins ,Biochemistry ,Permeability ,Cell Line ,Dermatitis, Atopic ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Immune system ,Adipokines ,Immunity ,Animals ,Humans ,Medicine ,RNA, Small Interfering ,Molecular Biology ,Glycoproteins ,Skin ,Transepidermal water loss ,integumentary system ,business.industry ,FOXP3 ,Lipid metabolism ,Cell Biology ,Atopic dermatitis ,Lipid Metabolism ,medicine.disease ,Recombinant Proteins ,Disease Models, Animal ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,Immunology ,Female ,Carrier Proteins ,business ,Biomarkers - Abstract
Adipokines modulate immune responses and lipid metabolism in allergic disease; however, little is known about their role in the skin barrier and atopic dermatitis (AD). We identified ZAG, an adipokine that regulates lipid mobilization, as a biomarker for AD. ZAG levels were consistently decreased in sera, T cells, and skin in human AD patients compared with healthy controls. ZAG was primarily detected in the stratum corneum along with FLG and LOR. Knockdown of ZAG with short hairpin RNA resulted in decreased FLG and increased TSLP. Topical ZAG treatment in AD mice recovered ZAG expression in the skin and improved AD-like symptoms, transepidermal water loss, and ceramide levels. Furthermore, topical ZAG treatment induced immunoregulatory effects, including reduction of IL-4, IL-17, and IFN-γ and increased Foxp3 in the skin and lymphoid organs. Interestingly, ZAG treatment also recovered decreased levels of ADAM17, an important player in skin barrier function and immune response in AD. Thus, ZAG deficiency is closely related to skin barrier function and the immune abnormalities of AD, and we suggest that restoration of ZAG may be a promising therapeutic option for the treatment of AD.
- Published
- 2019
34. Explorations of Team Dynamics: Advances in Theory and Methodology
- Author
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Man Mandy Fong, Virgil Fenters, Semin Park, Thomas A. O'Neill, Michael Morrison, Anthony Misisco, Amy H. Barron, Narda R. Quigley, Catherine G. Collins, Malika Khakhar, Chu-Hsiang Chang, Subir Biswas, Christopher R. Dishop, Margaret M. Luciano, John E. Mathieu, Nicole Larson, Steve W. J. Kozlowski, Matthew J. W. McLarnon, and Jeffrey Olenick
- Subjects
Unpacking ,Focus (computing) ,Dynamics (music) ,Management science ,General Medicine ,Sociology - Abstract
The proposed symposium highlights novel approaches to study team dynamics, with a focus on unpacking the complexities involved in working across multiple team performance episodes. Four studies are...
- Published
- 2019
35. Determination of the variations in levels of phenolic compounds in soybean (Glycine max Merr.) sprouts infected by anthracnose (Colletotrichum gloeosporioides )
- Author
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Soo-Chul Park, Jong Il Chung, Jae-Han Shim, Young Ah Cho, Yun-Hi Kim, Mi-Jeong Jeong, Semin Park, Youn-Sig Kwak, Sung Woo Jeong, Jong Sung Jin, Dong Won Bae, Sung Chul Shin, and Jung Han Lee
- Subjects
chemistry.chemical_classification ,Nutrition and Dietetics ,Phytoalexin ,Daidzein ,food and beverages ,Genistein ,Glycitein ,Isoflavones ,Coumestrol ,Biology ,chemistry.chemical_compound ,Horticulture ,chemistry ,Botany ,Genistin ,Daidzin ,Agronomy and Crop Science ,Food Science ,Biotechnology - Abstract
BACKGROUND Soybean sprouts (Kongnamool) are one of the most popular and nutritive traditional vegetables in East Asia. Anthracnose caused by Colletotrichum gloeosporioides is one of the most serious diseases of soybean sprouts. In order to obtain basic information for breeding and/or selecting soybean genotypes with increased natural defense against anthracnose, phenolic compounds were profiled for healthy and infected soybean (Glycine max Merr.) sprouts by using high-performance liquid chromatography coupled with tandem mass spectrometry. RESULTS Tryptophan and eight phenolic compounds (daidzin, genistin, malonyldaidzin, malonylgenistin, daidzein, glycitein, genistein and coumestrol) were determined from healthy and inoculated sprouts. Total identified phenolic content was 40.02 ± 0.03 mg kg−1, 99.4% of which was isoflavones. CONCLUSION The monitoring suggested that de novo induced glycitein appeared to act as a phytoalexin in the defence mechanism of the soybean sprouts against C. gloeosporioides, and constitutively formed seven phenolic components that functioned as phytoanticipins in the diseased soybean sprouts. © 2013 Society of Chemical Industry
- Published
- 2013
36. Development and validation of an LC–ESI–MS/MS method for simultaneous determination of levodopa, dopamine, L-α-methyldopa and 3-O-methyldopa in rat plasma
- Author
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Chi Yeon Kim, Young Ah Cho, On Nuri Seo, Woo-Kon Lee, Soo Taek Kim, Myung Je Cho, Semin Park, Sung Chul Shin, and Sung Woo Jeong
- Subjects
Detection limit ,Levodopa ,Chromatography ,Lc esi ms ms ,Coefficient of variation ,Pharmaceutical Science ,Tandem mass spectrometry ,High-performance liquid chromatography ,chemistry.chemical_compound ,chemistry ,Dopamine ,medicine ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) ,3-O-Methyldopa ,medicine.drug - Abstract
Parkinson’s disease (PD) is a progressive degenerative disorder of the central nervous system. Levodopa (L-dopa), dopamine precursor is the most effective therapeutic drug for PD patients. Levodopa (LDP) and its three metabolites in rat plasma were determined using high performance liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). Method validation was conducted in terms of linearity, accuracy, precision, recovery, specificity, limit of detection, limit of quantification and stability. Correlation coefficients (r2) were above 0.9965. The intra-day accuracy values at LLOQ (low limit of quantification), LQC (low quality control), MQC (medium quality control) and HQC (high quality control) levels were 85.7–103.3, 96.5–105.1, 90.7–100.1 and 94.2–101.3 %, respectively. The inter-day accuracy values at LLOQ, LQC, MQC and HQC levels were 77.6–112.0, 91.1–109.3, 84.3–101.0 and 88.2–103.9 %, respectively. The coefficient of variation (RSD) values of both intra- and inter-day results were within 6.7 and 8.5 %, respectively. The recoveries (mean ± %SD) for LLOQ, LQC, MQC and HQC were 82.7 ± 3.7–113 ± 2.8 %, 86.6 ± 5.7–110.3±3.4 %, 90.9 ± 3.6–106 ± 6.5 and 89.7 ± 4.5–97.4 ± 6.7 %, respectively. The coefficient of variation (RSD) values of both intra- and inter-day results were within 6.7 and 8.5 %, respectively. The validated LC–MS/MS method was applied successfully to the measurement of LDP and its metabolites in the rat plasma samples.
- Published
- 2012
37. Determination of polyphenol components of Lonicera japonica Thunb. using liquid chromatography–tandem mass spectrometry: Contribution to the overall antioxidant activity
- Author
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Jung Han Lee, Semin Park, Sung Chul Shin, On Nuri Seo, Chi Yeon Kim, Sang Kyung Choi, Soo-Jung Lee, Jong Sung Jin, Won Sup Lee, Gon-Sup Kim, and Yun-Hi Kim
- Subjects
chemistry.chemical_classification ,Chromatography ,Chemistry ,fungi ,Flavonoid ,food and beverages ,General Medicine ,Mass spectrometry ,Tandem mass spectrometry ,Hydroxycinnamic acid ,High-performance liquid chromatography ,Analytical Chemistry ,Column chromatography ,Liquid chromatography–mass spectrometry ,Polyphenol ,Food Science - Abstract
Three different mixtures of polyphenol components were isolated from the leaf, flower and stem of Lonicera japonica Thunb. via aqueous 70% methanol extraction followed by column chromatography over silica gel. The polyphenolic components of these mixtures were analysed via high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS) and compared with the reported data. Among the 25 characterized components, seven hydroxycinnamic acid derivatives and four flavonoid constituents were identified for the first time. The polyphenol compounds were validated and quantified on the basis of a representative polyphenol standard of the same group. The antioxidant activity of the polyphenol mixtures of the three tissues was determined. The antioxidant activity of the leaf was higher than that of the flower and stem.
- Published
- 2012
38. Determination of flavonoid level variation in onion (Allium cepa L.) infected by Fusarium oxysporum using liquid chromatography–tandem mass spectrometry
- Author
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Soo Taek Kim, Sung Woo Jeong, Jong Sung Jin, Sung Chul Shin, Semin Park, Euh Duck Jeong, Chi Yeon Kim, Dong Won Bae, Soo-Jung Lee, Youn-Sig Kwak, Gon-Sup Kim, and Jung Han Lee
- Subjects
chemistry.chemical_classification ,Chromatography ,biology ,fungi ,Flavonoid ,food and beverages ,General Medicine ,biology.organism_classification ,High-performance liquid chromatography ,Analytical Chemistry ,Bulb ,chemistry.chemical_compound ,chemistry ,Liquid chromatography–mass spectrometry ,Fusarium oxysporum ,Allium ,heterocyclic compounds ,Quercetin ,Isorhamnetin ,Food Science - Abstract
In order to evaluate the flavonoid level variation in an onion ( Allium cepa L.) infected by Fusarium oxysporum , the bulbs of a healthy onion and of an infected one were analysed for flavonoids via high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS). Among eleven flavonoids characterised, isorhamnetin 4′- O -galactoside ( 8 ) was identified in an onion for the first time. When the healthy bulb was inoculated with the fungus, the two quercetin derivatives ( 4 and 7 ) and the two isorhamnetin derivatives ( 5 and 9 ) underwent concentration changes typical for the defense materials against pathogens. The yellow granules that were accumulated on the abaxial epidermal cell layers after 8 days of inoculation were confirmed as quercetin ( 10 ) and isorhamnetin ( 11 ). It was deduced that they were produced from flavonoids 4 , 5 , 7 and 9 by hydrolysis enzyme of the fungus.
- Published
- 2012
39. Phospholipid profiling of 57 soybean (Glycine max) varieties by high-performance liquid chromatography-tandem mass spectrometry and principal component analysis to classify Korean soybean germplasm
- Author
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Gon-Sup Kim, Soo Taek Kim, Yun-Hi Kim, Jong Il Chung, Chi Yeon Kim, Sung Chul Shin, Soo-Jung Lee, Sung Woo Jeong, Jae-Han Shim, and Semin Park
- Subjects
Pharmacology ,Germplasm ,Chromatography ,Chemistry ,Clinical Biochemistry ,Phospholipid ,General Medicine ,Repeatability ,Mass spectrometry ,Tandem mass spectrometry ,Biochemistry ,High-performance liquid chromatography ,Analytical Chemistry ,chemistry.chemical_compound ,Drug Discovery ,Principal component analysis ,Molecular Biology - Abstract
Phospholipids (PLs) in 57 varieties of soybeans were profiled by high-performance liquid chromatography–electrospray ionization-tandem mass spectrometry and principal component analysis (PCA) to discriminate PL-rich soybeans. The PL calibration curves showed linearity with correlation coefficients >0.9964. The recoveries at 5 mg/L spiked level ranged from 72.8 to 86.7% and those at 12.5 mg/L from 78.2 to 85.1%. The repeatability at a 5 mg/L spiked level ranged from 2.5 to 7.0% and those at 12.5 mg/L from 1.2 to 3.9%. The average total PL content in the 57 soybean varieties was about 35.3 mg/kg. The total PL content was the highest in Aodaiz (35, 48.7 ± 1.4 mg/kg) and the lowest in Poongsannamul (56, 16.0 ± 0.7 mg/kg). The PCA showed that RS-78sun (42), Gyeongsang #1 (3) and Aodaiz (35) are the most improved varieties of the investigated 57 varieties from the viewpoint of PL content. Copyright © 2012 John Wiley & Sons, Ltd.
- Published
- 2012
40. Determination of polyphenol levels variation in Capsicum annuum L. cv. Chelsea (yellow bell pepper) infected by anthracnose (Colletotrichum gloeosporioides) using liquid chromatography–tandem mass spectrometry
- Author
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Gon-Sup Kim, Won Young Jeong, Yun-Hi Kim, Soo-Jung Lee, Chae-Shin Lim, Dong Won Bae, Sung Woo Jeong, Semin Park, Jong Sung Jin, Jung Han Lee, and Sung Chul Shin
- Subjects
chemistry.chemical_classification ,biology ,Phytoalexin ,General Medicine ,biology.organism_classification ,High-performance liquid chromatography ,Analytical Chemistry ,Horticulture ,chemistry.chemical_compound ,chemistry ,Liquid chromatography–mass spectrometry ,Polyphenol ,Botany ,Pepper ,Kaempferol ,Solanaceae ,Legume ,Food Science - Abstract
Healthy fruits of Capsicum annuum L. cv. Chelsea (yellow bell pepper) and one infected by Colletotrichum gloeosporioides were analysed for polyphenols via high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS). Among seven polyphenols characterized, four components in the C. annuum fruits were identified for the first time. To investigate the characteristics of the polyphenols as defence materials, the content change of the fruit polyphenols inoculated with C. gloeosporioides was monitored by HPLC. It was observed for the first time that de novo induced N-caffeoyl putrescine (1) and caffeoyl O-hexoside (2) appeared to act as a phytoalexin in the defence mechanism of the C. annuum fruits against C. gloeosporioides, and constitutively formed feruloyl O-glucoside (3), kaempferol O-pentosyldihexoside (4) and dihydroxyflavone O-hexoside (7) as a phytoanticipin in the diseased C. annuum fruits.
- Published
- 2012
41. Determination of polyphenols in three Capsicum annuum L. (bell pepper) varieties using high-performance liquid chromatography-tandem mass spectrometry: Their contribution to overall antioxidant and anticancer activity
- Author
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A. M. Abd El-Aty, Chae-Shin Lim, Sung W. Jeong, Semin Park, Young Ah Cho, Gon-Sup Kim, Yun-Hi Kim, Jae-Han Shim, Jong S. Jin, Sung C. Shin, Jung H. Lee, Won Young Jeong, and Soo Jin Lee
- Subjects
Antioxidant ,Cell Survival ,medicine.medical_treatment ,Flavonoid ,Antineoplastic Agents ,Filtration and Separation ,Orange (colour) ,High-performance liquid chromatography ,Antioxidants ,Cinnamic acid ,Analytical Chemistry ,Structure-Activity Relationship ,chemistry.chemical_compound ,Column chromatography ,Tandem Mass Spectrometry ,Cell Line, Tumor ,Pepper ,medicine ,Humans ,Chromatography, High Pressure Liquid ,Cell Proliferation ,chemistry.chemical_classification ,Chromatography ,Dose-Response Relationship, Drug ,Molecular Structure ,Polyphenols ,food and beverages ,Stereoisomerism ,chemistry ,Polyphenol ,Fruit ,Drug Screening Assays, Antitumor ,Capsicum ,HeLa Cells - Abstract
A mixture of polyphenol components was isolated from the fruits of C. annuum L. cv. Cupra, C. annuum L. cv. Orange glory, and C. annuum L. cv. ST4712 (CLST), via 70% methanol extraction followed by column chromatography over silica gel. The polyphenol components of the mixture were analyzed via HPLC-MS/MS and compared with the reported data. Three cinnamic acid derivatives and five flavonoid components in the fruits of the three varieties were identified for the first time in this study. The antioxidant activity and anticancer effect of the polyphenol mixtures of the three fruits were determined. The antioxidant and anticancer activities of CLST were substantially higher than those of C. annuum L. cv. Cupra and C. annuum L. cv. Orange glory. The high activities of CLST were attributed to the much higher concentration of quercetin derivatives in CLST.
- Published
- 2011
42. Flavonoid profiling in three citrus varieties native to the Republic of Korea using liquid chromatography coupled with tandem mass spectrometry: contribution to overall antioxidant activity
- Author
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Jae Hoon Kim, Gon-Sup Kim, A. M. Abd El-Aty, Sung Chul Shin, On Nuri Seo, Jong Sung Jin, Semin Park, Hae Gyeong Kim, Jung Han Lee, Soo-Jung Lee, and Jae-Han Shim
- Subjects
Pharmacology ,chemistry.chemical_classification ,Chromatography ,ABTS ,Chemistry ,DPPH ,Elution ,Clinical Biochemistry ,Flavonoid ,Ethyl acetate ,General Medicine ,Tandem mass spectrometry ,Mass spectrometry ,Coumarin ,Biochemistry ,Analytical Chemistry ,chemistry.chemical_compound ,Drug Discovery ,Molecular Biology - Abstract
A mixture of flavonoid components was isolated from the fruit peel of three varieties of citrus native to Republicof Korea, Citrus leiocarpa Hort. ex Tanaka (CLHT), Citrus aurantium L. (CAL) and Citrus erythrosa Hort. (CEH), via 70% methanolextraction followed by ethyl acetate elution over a silica gel cartridge. The flavonoid components of the mixture were ana-lyzed via high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) in positive-ion mode and acomparison ofthe reported data.Among 17 characterized components, twoflavanones, four flavones and twocoumarinderi-vatives in the fruit peel of the three varieties were identified for the first time. The individual characterized components werequantified via HPLC-UV. The flavanones dominated in CAL, whereas the flavones prevailed in CLHT and CEH. The antioxidantactivity of the flavonoid mixture of the fruit peel was determined via DPPH † , ABTS †+ and reducing power assays. The antiox-idant activity of CEH and CAL was greater than that of CLHT. Copyright © 2011 John Wiley & Sons, Ltd.Keywords: citrus; flavonoids; coumarin; HPLC-MS/MS; antioxidant activity
- Published
- 2011
43. Characterisation of flavonoids in Orostachys japonicus A. Berger using HPLC–MS/MS: Contribution to the overall antioxidant effect
- Author
-
Nak-Ju Sung, Soo-Jung Lee, Won Sup Lee, Gon-Sup Kim, Sung Chul Shin, Hae Kyung Kim, Jin Young Choi, Chae-Shin Lim, Jung Han Lee, Won Young Jeong, and Semin Park
- Subjects
chemistry.chemical_classification ,ABTS ,Chromatography ,Stereochemistry ,DPPH ,Flavonoid ,General Medicine ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Glucoside ,Myricetin ,Kaempferol ,Quercetin ,Procyanidin dimer ,Food Science - Abstract
Orostachys japonicus cultivated in the Republic of Korea was analysed for flavonoid content via HPLC coupled to MS/MS. Amongst 16 compounds that were characterised, eight flavonoids and one alkaloid were characterised for the first time: two procyanidin dimer gallate isomers ( 1 and 2 ), epigallochatechin-3-gallate ( 3 ), two procyanidin dimer digallate isomers ( 4 and 9 ), quercetin 3- O -rhamnosyl-7- O -glucoside ( 6 ), myricetin 3- O -glucoside ( 10 ), kaempferol ( 16 ) and N 1 , N 5 , N 10 -tri- p -( E,E,E )-coumaroylspermidine ( 15 ). The identified compounds were quantified by HPLC–UV/DAD. The antioxidant activity of the O. japonicus flavonoids was determined via 2,2-diphenyl-1-picrylhydrazyl radical (DPPH • ), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS •+ ) and nitric oxide radical (NO • ) scavenging assays.
- Published
- 2011
44. New Directions in Research on Conflict Dynamics
- Author
-
Gergana Todorova, Semin Park, and Laurie R. Weingart
- Subjects
Team composition ,Longitudinal study ,business.industry ,media_common.quotation_subject ,General Medicine ,Public relations ,Creativity ,Creative synthesis ,Dynamics (music) ,Team conflict ,Conflict management ,Sociology ,business ,media_common - Abstract
Although time affects how individuals interact together in teams, we know little about how time influences the evolution of conflict interactions and their impact on important team outcomes. Conflict dynamics is likely to determine the extent to which team members create new products, perform, and stay viable over time. Our symposium brings together five papers which examine conflict dynamics using different research approaches and theoretical perspectives. The current collection of papers contribute to research on team dynamics, creativity, team composition, conflict management, and learning; and has important implications for theory, research methods advancement, and practice on how to make teams more effective. A Longitudinal Study of Antecedents and Outcomes of Team Conflict Dynamics Presenter: Nicole Larson; U. of Calgary Presenter: Thomas Alexander O'Neill; U. of Calgary Presenter: Matthew McLarnon; Oakland U. Creative Synthesis and Conflict Dynamics in Innovation teams: A Latent Growth Analysis Pre...
- Published
- 2018
45. Simultaneous determination of phoxim and its photo-transformation metabolite residues in eggs using liquid chromatography coupled with electrospray ionization tandem mass spectrometry
- Author
-
Soo Taek Kim, A. M. Abd El-Aty, Semin Park, Ok Ja Choi, Jung Han Lee, Jae-Han Shim, M. Im, Soo-Jung Lee, Hae Gyeong Kim, Sung Chul Shin, Won Young Jeong, and Hyung Jin Park
- Subjects
Chromatography, Reverse-Phase ,Spectrometry, Mass, Electrospray Ionization ,Chemical ionization ,Electrospray ,Chromatography ,Chemistry ,Eggs ,Electrospray ionization ,Selected reaction monitoring ,Pesticide Residues ,Organothiophosphorus Compounds ,Mass spectrometry ,Tandem mass spectrometry ,Biochemistry ,Analytical Chemistry ,chemistry.chemical_compound ,Tandem Mass Spectrometry ,Phoxim ,Environmental Chemistry ,Solid phase extraction ,Spectroscopy - Abstract
The principal objective of this study was to develop an appropriate, sensitive, and selective method for the simultaneous quantitative determination of phoxim and its photo-transformation product, O,O-diethyl alpha-cyanobenzylideneamino-thiophosphonate (DCTP) in both chicken and quail eggs. Eggs (1 g) were blended with anhydrous magnesium sulfate (1 g) for sample pretreatment and extracted with acetonitrile. The extracts were then further purified with SPE silica gel tubes deactivated with trimethylamine. Residues were analyzed via a reversed phase-liquid chromatography-tandem mass spectrometry (RP-LC-MS/MS) in positive-ion electrospray ionization (ESI) mode. Tebufenozide was utilized as an internal standard for the quantification of phoxim and its metabolite residues. The identification and quantification of analytes were based on ion transitions monitored by multiple reaction monitoring (MRM). LC-MS/MS analysis was performed from 0.02 to 1 mg kg(-1) and correlation coefficients (r(2)) ranging from 0.998 to 0.999 were obtained for both analytes in blank egg extracts. The relative standard deviations (RSDs) of intra- and inter-day variations ranged from 2.1% to 6.7% and from 2.8% to 6.4% for phoxim and DCTP in chicken and quail eggs. At all levels of fortification (0.02, 0.05, and 0.125 mg kg(-1)), the recoveries fell within a range of 81.3% to 93.6% for phoxim and 83.3% to 90.1% for DCTP. The matrix effect was2%, due to the partial dilution of the sample. Decision limits (CCalpha) and detection capabilities (CCbeta) were in the range of 0.0005-0.0044 and 0.0054-0.0224 mg kg(-1), respectively. The method was evaluated further by analyzing real samples purchased from markets. All chicken and quail egg samples were free from residues of the target compounds.
- Published
- 2010
46. Determination of phospholipids in soybean (Glycine max (L.) Merr) cultivars by liquid chromatography–tandem mass spectrometry
- Author
-
Dong Won Bae, Soo-Jung Lee, Sung Joong Lee, Jong Sung Jin, Sung Chul Shin, Semin Park, Jong Il Chung, Nak-Ju Sung, and Jin Young Choi
- Subjects
chemistry.chemical_compound ,Chromatography ,chemistry ,Liquid chromatography–mass spectrometry ,Phosphatidylcholine ,Selected reaction monitoring ,Extraction (chemistry) ,Ammonium formate ,Composition (visual arts) ,Cultivar ,Methanol ,Food Science - Abstract
Special interest has been focused on the variation in the composition and content of phospholipids (PLs) in soybeans following genetic modification, due to their beneficial effects on human health. As part of the attempt to discover PL-rich soybeans, a total of 12 cultivars were bred and their PL contents were determined by LC–MS/MS. In the LC, 0.1 M ammonium formate in methanol was essential to obtain good peak separation with minimum tailing. The LC–MS/MS method operating in the multiple reaction monitoring (MRM) mode, with two transitions monitored for each PL, provided good selectivity and sensitivity for the determination of PLs. All the calibration curves were linear, with correlation coefficients higher than 0.990. The extraction recoveries ranged from 75.6% to 89.9%. The limit of quantitations (LOQs) were within the range of 0.16–16.7 μg/kg. The average content of total PLs in the 12 soybean cultivars was about 75.7 mg/kg. The total PL and PC (phosphatidylcholine) contents were highest in the Gaechuck#2 cultivar. From the viewpoint of the PL content, Gaechuck#2 was demonstrated to be the most improved variety in the 12 cultivars investigated.
- Published
- 2010
47. Residue analysis of multi-class pesticides in watermelon by LC-MS/MS
- Author
-
A. M. Abd El-Aty, Sung Chul Shin, Won Sup Lee, Sung Joong Lee, Soo Taek Kim, Semin Park, Sung Woo Jeong, Hae Gyeong Kim, Won Young Jeong, and Jae-Han Shim
- Subjects
Chromatography ,Citrullus lanatus ,biology ,Pesticide residue ,Selected reaction monitoring ,Filtration and Separation ,Reversed-phase chromatography ,Pesticide ,biology.organism_classification ,Tandem mass spectrometry ,High-performance liquid chromatography ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Ammonium formate - Abstract
As watermelon is farmed primarily by protected and successive cultivation techniques, a number of pesticides are required for the control of pests and diseases. To evaluate the harmful effects of pesticides in watermelon and to guarantee consumers' safety, a rapid screening process for pesticides is required. A LC-MS/MS method was applied for the direct quantitation of 44 pesticide residues in watermelon. A Zorbax XDB-C(18) column was selected for analysis, with a mobile phase consisting of a gradient system of water and 5 mM methanolic ammonium formate. MS/MS experiments were performed in ESI positive ion and multiple reaction monitoring modes. The LOQs were in the range of 1-26 microg/kg, thereby indicating good sensitivity. Most of the recoveries ranged between 70-131% with RSDs < or = 20%. We suggested that the amount of pesticide residues such as pyroquilon (pyn), boscalid (bd), and dimethomorph (di) in amides (AM) and cinosulfuron (ci) in ureas (UR) may have been overestimated for the pesticides owing to increased alpha-error risk, whereas the amounts of pesticide residues, such as imibenconazole (ie) in the triazoles (TR) and fenpyroximate (fee) in the imidazoles (IM), may have been underestimated as the result of increased beta-error risk. The current method allowed for the rapid quantitation and identification of low pesticide levels in the watermelon samples. No pesticide residues were detected in any of the surveyed watermelons obtained from eight local markets in the Republic of Korea. Statistical analysis of the recoveries classified the 44 pesticides into nine groups and three overall categories.
- Published
- 2010
48. Zum § 201 vom KBGB
- Author
-
Semin Park
- Subjects
General Engineering - Published
- 2008
49. Development and validation of a high-performance liquid chromatography-tandem mass spectrometric method for simultaneous determination of bupropion, quetiapine and escitalopram in human plasma
- Author
-
Semin, Park, Chul-Soo, Park, Sung Joong, Lee, Boseok, Cha, Young Ah, Cho, Yi, Song, Eun Ae, Yu, Gon-Sup, Kim, Jong Sung, Jin, A M, Abd El-Aty, H A, El-Banna, Ahmet, Hacımüftüoğlu, Jae-Han, Shim, and Sung Chul, Shin
- Subjects
Quetiapine Fumarate ,Tandem Mass Spectrometry ,Humans ,Citalopram ,Bupropion ,Antidepressive Agents ,Chromatography, High Pressure Liquid - Abstract
In the present study, an effective high performance liquid chromatography-tandem mass spectrometric (HPLC/MS/MS) method was developed and validated to simultaneously determine bupropion (BUP), quetiapine (QUE) and escitalopram (ESC) in human plasma using carbidopa as the internal standard. Chromatographic separation was achieved on a Waters Sun Fire C18 column using reversed-phase chromatography. The MS/MS experiment was performed in positive ion multiple reaction monitoring mode to produce product ions of m/z 240.3 → 184.2 for BUP, 384.2 → 253.1 for QUE, 325.3 → 109.3 for ESC and 227.2 → 181.2 for the internal standard. The method showed good linearity (R(2) ≥ 0.997), precision (relative standard deviation ≤7.5%), satisfactory intra- and interday accuracy (88.4-113.0%) and acceptable extraction recovery (87.2-115.0%), matrix effect (84.5.5-108.7%) and stability (92.3-103.5%). The method was successfully applied to determine the concentrations of BUP, QUE and ESC in human plasma samples.
- Published
- 2014
50. Flavonoid profiles of immature and mature fruit tissues of Citrus grandis Osbeck (Dangyuja) and overall contribution to the antioxidant effect
- Author
-
Eun Ae, Yu, Gon-Sup, Kim, Ji Eun, Lee, Semin, Park, Song, Yi, Soo Jung, Lee, Jae Hoon, Kim, Jong Sung, Jin, A M, Abd El-Aty, Jae-Han, Shim, and Sung Chul, Shin
- Subjects
Citrus ,Molecular Structure ,Plant Extracts ,Fruit ,Antioxidants ,Chromatography, High Pressure Liquid ,Mass Spectrometry - Abstract
Citrus fruits are a valuable functional food and their peel is used in East Asian folk medicine. In this study, the polar components of the fruit tissues of Citrus grandis Osbeck were analyzed using high-performance liquid chromatography-tandem mass spectrometry and compared with reported data. Among the 13 characterized compounds, eight flavonoids and one coumarin were identified for the first time in fruit tissues. The total amount of the identified components was the largest for the immature fruit peel, followed by mature fruit peel, mature fruit flesh, and immature fruit flesh. Naringin (2) and neohesperidin (3) were particularly rich in all samples. The antioxidant activity of the flavonoids extracted from fruit tissues increased in a dose-dependent manner. The activity of the fruit peels was significantly higher than that of the fruit flesh. Copyright © 2014 John WileySons, Ltd.
- Published
- 2014
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