Junseong Kim

The clinical implications of early diastolic notch in third trimester Doppler waveform analysis of the uterine artery.

To evaluate the clinical utility of third trimester Doppler waveform analysis of the uterine artery in predicting complicated pregnancies and fetal well-being, we compared adverse pregnancy outcomes in 2321 women with the presence of an elevated systolic-diastolic ratio (greater than 2.6) with the persistence of an early diastolic notch and with the combination of an elevated systolic-diastolic ratio and an early diastolic notch. The positive predictive values are 47.5%, 82.9%, and 92.6%, respectively. From these data we can conclude that determination of the presence or absence of an early diastolic notch is more valuable in predicting the perinatal outcome than is the presence of an elevated systolic-diastolic ratio alone. We also suggest that an assessment of the uterine artery systolic-diastolic ratio combined with the evaluation for persistent early diastolic notch would be a clinically useful test for fetal well-being.

An efficient liposomal gene delivery vehicle using Sendai F/HN proteins and protamine.

By means of a simple mixing procedure, we have constructed cationic Sendai virosomes consisting of fusogenic viral F/HN proteins and cationic lipids. Sendai virus F/HN proteins were purified by Triton X-100 treatment and sequential centrifugation, and then quantitatively added to cationic liposomes. The presence of HN proteins is essential for hemolytic activity of Sendai virus as well as efficient gene transfection. The amount of detergent added for purification of F/HN proteins was also crucial for hemolytic activity. The relevance of F/HN proteins in the gene-transfer capability of the cationic Sendai F/HN virosomes (CSVs) was verified by heat inactivation of the F/HN proteins, and cell-binding competition. DNA condensation by protamine sulfate was able to further enhance the transfection efficiency and serum resistance of CSV. The enhanced transfection efficiency of protamine-condensed DNA-encapsulating cationic Sendai F/HN virosomes (PCSVs) may result from specific and efficient cell binding mediated by F/HN proteins and efficient DNA encapsulation by protamine. The DNA condensation by protamine was crucial for systemic in vivo gene transfer by CSVs. The PCSVs exhibited a higher gene expression in various organs, especially the liver, compared to DOTAP/Chol lipoplexes. These results demonstrate the potential for the use of PCSV as gene delivery vehicles for systemic gene transfer.

Experimental Analysis on AC Loss and Fault Current Test of HTS Coils Co-Wound With Various Inserted Materials

A significant number of recent studies have explored the impact of many kinds of winding insulation conditions on high-temperature superconducting (HTS) coils for the application of electric devices. HTS coil co-wound with turn-to-turn inserted materials could be an appropriate alternative to the no-insulation coil because of the poor charge-discharge delay and unexpected quench behavior of the no-insulation coil. In addition, the co-wound HTS coil has good thermal stability and mechanical integrity, making it useful for superconducting applications such as superconducting magnetic energy storage (SMES) and superconducting fault current limiter (SFCL). However, studies of the co-wound HTS coil have explored dc electrical characteristics, but not ac electrical characteristics. Research into ac electrical characteristics is essential because of the operation sequence of the SMES and fault occurrence for the SFCL. In this paper, the ac electrical characteristics of HTS coils co-wound with various inserted materials were experimentally analyzed. Tested coils were co-wound with either Kapton, stainless steel, or copper tape at every turn of the winding, and one no-insulation coil served as a reference. AC loss, fault current, and recovery time were measured at 77 K, self-field.

Intrathecal fentanyl decreases the optimal effect site concentration of propofol during spinal anaesthesia

The aim of this study was to assess the possible difference in the optimal effect site concentration of propofol for conscious sedation during spinal anaesthesia with or without intrathecal fentanyl in patients undergoing urologic surgery. The hypothesis was that intrathecal fentanyl would decrease the effect site concentration of propofol needed for conscious sedation.

Experimental Analysis of Thermally and Magnetically Triggered Switch for High-Tc Superconducting Power Converting System

In this paper, characteristics of a thermally and magnetically triggered switch for a high-Tc superconducting (HTS) power converting system are experimentally analyzed. For verifying the efficiency of the suggested switch, current charging and discharging tests using heater-triggered switch with or without an external magnetic field are performed. Charging tests are performed with two charging sequences, i.e., CS1 and CS2. Each sequence is experimented with two kinds of heater currents to maintain different temperatures. Saturation current and saturation time are detected to calculate the pumping rate. Two discharging sequences, i.e., DS1 and DS2, are used for discharging tests with heater current to maintain 120 K. From the results, normalized load energies are calculated and compared.