• BMB Reports
• /
• v.49 no.10
• /
• pp.548-553
• /
• 2016

Mesenchymal stem cells (MSCs) are widely used in cartilage tissue engineering to repair articular cartilage defects. However, hypertrophy of chondrocytes derived from MSCs might hinder the stabilization of hyaline cartilage. Thus, it is very important to find a suitable way to maintain the chondrogenic phenotype of chondrocytes. It has been reported that cordycepin has anti-inflammatory and anti-tumor functions. However, the role of cordycepin in chondrocyte hypertrophy remains unclear. Therefore, the objective of this study was to determine the effect of cordycepin on chondrogenesis and chondrocyte hypertrophy in MSCs and ATDC5 cells. Cordycepin upregulated chondrogenic markers including Sox9 and collagen type II while down-regulated hypertrophic markers including Runx2 and collagen type X. Further exploration showed that cordycepin promoted chondrogenesis through inhibiting Nrf2 while activating BMP signaling. Besides, cordycepin suppressed chondrocyte hypertrophy through PI3K/Bapx1 pathway and Notch signaling. Our results indicated cordycepin had the potential to maintain chondrocyte phenotype and reconstruct engineered cartilage.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2006.08a
• /
• pp.156-156
• /
• 2006

• Journal of Biomedical Engineering Research
• /
• v.40 no.1
• /
• pp.20-31
• /
• 2019

Medical device performance management is an activity that allows a device to be safely used and maintained even after it is put on the market. The purpose of this study is to provide procedures and criteria for selection of medical device items that should manage the safety and performance among medical devices in hospital. Investigate the performance management status of medical devices in hospitals and identify the performance management status by domestic and advanced regulatory agencies. Provides selection procedures and test methods for medical devices subject to performance management in hospitals based on medical device risk management and reliability. In addition, a case study on drug infusion pumps was conducted.

• Journal of Biomedical Engineering Research
• /
• v.28 no.5
• /
• pp.703-712
• /
• 2007

In this paper, we designed the RFID(Radio Frequency Identification) Emergency Medical Information System(REMIS). This REMIS offers the emergency patient's medical information using RFID and HL7(Health Level 7) to an emergency medical technician. In emergency situation as like coma, if the communication, from the patient's current location to the hospital, is possible, REMIS offer the medical information of the patient through REMIS server to an emergency medical technician. In the state of communication blocked, REMIS can offer the patient identification and the emergency information through RFID tag, which the patient wear, to an emergency medical technician. When this system was designed, the protection of the patient's medical information and their privacy was considered, and the HL7 was used to be compatible with another medical systems. Therefore, in this paper, REMIS was designed that it is always possible to offer the emergency patient's information to an emergency medical technician regardless of any communication status and to improve the emergency rescue process, effectively.

• Journal of Biomedical Engineering Research
• /
• v.29 no.1
• /
• pp.82-87
• /
• 2008

In this paper, the study was carried out to design and implement the medical compound stimulator based on the preexisting individual medical stimulators with Low frequency, High frequency and cooling stimulation. The proposed equipment is designed to compound all the functions including a cooling stimulation with a range of $0{\sim}20^{\circ}C$ and the verified low and high frequencies of 250Hz, 500Hz, 1KHz and 1MHz respectively from the previous clinical experiment with a consideration of its credibility and efficiency. Also, it was constructed by using a new technique, thermoelectricity semiconductor with a consideration of miniaturization and stability. In accordance with patients' treatment purpose, the hand piece of low frequency/cooling stimulation and High frequency/cooling stimulation were separately designed for convenience. The frequency, accuracy and other factors of implemented medical compound stimulator was satisfied according to its measurement. It was also tested by Korean Testing Laboratory (KTL) for its stability and efficacy and it confirmed that the medical compound stimulator is suitable for use as it fits in with the medical equipment standards.

• Journal of Biomedical Engineering Research
• /
• v.44 no.2
• /
• pp.99-108
• /
• 2023

According to the COVID-19, development of various medical software based on IoT(Internet of Things) was accelerated. Especially, interest in a central software system that can remotely monitor and control ventilators is increasing to solve problems related to the continuous increase in severe COVID-19 patients. Since medical device software is closely related to human life, this study aims to develop central monitoring system that can remotely monitor and control multiple ventilators in compliance with medical device software development standards and to verify performance of system. In addition, to ensure the safety and reliability of this central monitoring system, this study also specifies risk management requirements that can identify hazardous situations and evaluate potential hazards and confirms the implementation of cybersecurity to protect against potential cyber threats, which can have serious consequences for patient safety. As a result, we obtained medical device software manufacturing certificates from MFDS(Ministry of Food and Drug Safety) through technical documents about performance verification, risk management and cybersecurity application.

• Proceedings of the KOSOMBE Conference
• /
• v.1990 no.11
• /
• pp.103-104
• /
• 1990

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.07a
• /
• pp.260-260
• /
• 2004

• Journal of Microbiology and Biotechnology
• /
• v.19 no.10
• /
• pp.1197-1200
• /
• 2009

The whitening effect, tyrosinase inhibition, and cytotoxicity of neoagarotetraose were measured after its purification from hydrolyzed agar by gel filtration chromatography. In melanoma B16F10 cells, the melanin content of neoagarotetraose-treated cells was the same as that treated by kojic acid or arbutin. In addition, tyrosinase of melanoma cells was strongly inhibited by neoagarotetraose at a concentration of $1{\mu}g/ml$ and similarly inhibited at 10 and $100{\mu}g/ml$ compared with those by arbutin or kojic acid. The activity of mushroom tyrosinase showed a 38% inhibition by neoagarotetraose at $1{\mu}g/ml$, and this inhibitory effect was more efficient than that by kojic acid. Neoagarotetraose revealed a similar $IC_{50}$ (50% inhibition concentration) value for mushroom tyrosinase as that by kojic acid. These data suggest that the neoagarotetraose generated from agar by recombinant $\beta$-agarase might be a good candidate as a cosmetic additive for the whitening effect.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.6
• /
• pp.537-541
• /
• 2009

The objective of this study was to investigate the possibility of using low-amperage electrical treatment (LAET) as a selective bacteriocide. Mixtures containing Escherichia coli, Staphylococcus aureus, and Vibrio parahaemolyticus were treated with different electric current intensities and for different times. The results showed that at 263 mA, treating bacteria for 100 ms eliminated all V. parahaemolyticus colonies. Although LAET reduced the populations of the three microorganisms, V. parahaemolyticus was more injured by LAET than S. aureus and E. coli when treated at the same processing conditions.