Chung-Ang University 8 articles published in JoVE Chemistry Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch Myeongsu Jeong*1, Jiyoon Park*1, Kwonjung Lee*1, Sunbum Kwon1 1Department of Chemistry, Chung-Ang University Photoisomerization quantum yield is a fundamental photophysical property that should be accurately determined in the investigation of newly developed photoswitches. Here, we describe a set of procedures to measure the photoisomerization quantum yield of a photochromic hydrazone as a model bistable photoswitch. Engineering Evaluating the Electrochemical Properties of Supercapacitors using the Three-Electrode System Hojong Eom1, Jihyeon Kang1, Seohyeon Jang1, Ohhyun Kwon1, Seyoung Choi1, Junhyeop Shin1, Inho Nam1 1School of Chemical Engineering and Materials Science, Department of Intelligent Energy and Industry, Chung-Ang University The protocol describes the evaluation of various electrochemical properties of supercapacitors using a three-electrode system with a potentiostat device. Engineering Elaborate Control of Inkjet Printer for Fabrication of Chip-based Supercapacitors Seyoung Choi1, Jihyeon Kang1, Seohyeon Jang1, Hojong Eom1, Ohhyun Kwon1, Junhyeop Shin1, Inho Nam1 1School of Chemical Engineering and Materials Science, Department of Intelligent Energy and Industry, Department of Advanced Materials Engineering, Chung-Ang University This paper provides a technique for manufacturing chip-based supercapacitors using an inkjet printer. Methodologies are described in detail to synthesize inks, adjust software parameters, and analyze the electrochemical results of the manufactured supercapacitor. Bioengineering Lab-on-a-CD Platform for Generating Multicellular Three-dimensional Spheroids Daehan Kim1, Gi-Hun Lee1, Jiheum Park2, Jung Chan Lee2, Joong Yull Park1 1Department of Mechanical Engineering, Graduate School, Chung-Ang University, 2Department of Biomedical Engineering, College of Medicine, Seoul National University We present a motor-powered centrifugal microfluidic device that can cultivate cell spheroids. Using this device, spheroids of single or multiple cell types could be easily cocultured under high gravity conditions. Medicine Surgical Labyrinthectomy of the Rat to Study the Vestibular System Mun Young Chang1, Moo Kyun Park2, So Hyeon Park2, Myung-Whan Suh2, Jun Ho Lee2, Seung Ha Oh2 1Department of Otolaryngology-Head and Neck Surgery, Chung-Ang University College of Medicine, 2Department of Otolaryngology-Head and Neck Surgery, Seoul National University Hospital This protocol describes the surgical labyrinthectomy of a rat, which is a useful method for studying the vestibular system. Bioengineering Synthesis of Multi-walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties Youngmin Seo*1, Chanhwi Park*2, Jaewoo Son2, Kyungwoo Lee2, Jangsun Hwang2, Yeonho Jo2, Dohyun Lee2, Muhammad Saad Khan2, Sachin Ganpat Chavan2, Yonghyun Choi2, Dasom Kim2, Assaf A Gilad3, Jonghoon Choi2 1Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology, 2School of Integrative Engineering, Chung-Ang University, 3Division of Synthetic Biology and Regenerative Medicine, Institute for Quantitative Health Science and Engineering, Michigan State University In this study, antimicrobial nanomaterials were synthesized by acidic oxidation of multiwalled carbon nanotubes and subsequent reductive deposition of silver nanoparticles. Antimicrobial activity and cytotoxicity tests were performed with the as-prepared nanomaterials. Bioengineering A Paired Bead and Magnet Array for Molding Microwells with Variable Concave Geometries Gi-Hun Lee1, Youngjoon Suh1, Joong Yull Park1 1School of Mechanical Engineering, College of Engineering, Chung-Ang University This manuscript introduces a robust method of fabricating concave microwells without the need for complex high-cost facilities. Using magnetic force, steel beads, and a through-hole array, several hundred microwells were formed in a 3 cm x 3 cm polydimethylsiloxane (PDMS) substrate. Neuroscience Measuring Synaptic Vesicle Endocytosis in Cultured Hippocampal Neurons Seth Villarreal1, Sung Hoon Lee1,2, Ling-Gang Wu1 1National Institute of Neurological Disorders and Stroke, 2College of Pharmacy, Chung-ang University Synaptic vesicle endocytosis is detected by light microscopy of pHluorin fused with synaptic vesicle protein and by electron microscopy of vesicle uptake.