Sung Hyun Lee

The antioxidant activity and hepatoprotective potential of Cirsium setidens Nakai, a widely used medicinal plant, were investigated. The n-butanol (n-BuOH) fraction of leaves and roots of C. setidens had a higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the other soluble fractions. The n-BuOH fraction of roots of C. setidens had a significant hepatoprotective activity at a dose of 500 mg/kg compared to that of a standard agent. The biochemical results were confirmed

Abstract In this study, the survival fraction (SF) and relative biological effectiveness (RBE) of pancreatic cancer cells exposed to spread-out Bragg peak helium, carbon, oxygen, and neon ion beams are estimated from the measured microdosimetric spectra using a microdosimeter and the application of the microdosimetric kinetic (MK) model. To measure the microdosimetric spectra, a 3D mushroom silicon-on-insulator microdosimeter connected to low noise readout electronics (MicroPlus probe) was used.

The CdTe-ZnTe or CdTe–MnTe alloy system is evaluated for application in high efficiency polycrystalline thin film multijunction solar cells. CdZnTe alloy films with 1.6 and 1.7 eV band gap and CdMnTe with 1.6 and 1.8 eV were deposited by RF magnetron sputtering from targets made of mixed powders of CdTe and ZnTe (25% and 40%) or MnTe (13% and 25%), respectively. Without postdeposition treatment, however, both of these alloy films exhibit quite low photovoltaic performance when used to make cells

The effects of gamma irradiation on the survival and development of C. sinensis metacercariae were studied to evaluate the feasibility of irradiation as a control measure for clonorchiasis. Pseudorasbora parva were collected at an endemic river of clonorchiasis and were used for irradiation of the fluke in three schemes. The first (Scheme 1) was irradiation of the isolated metacercariae from the fish followed by infection to experimental rats. The second (Scheme 2) was irradiation of the fish, a

Light detection and ranging (LIDAR) is one of solutions to extract 3D depth image of objects. Especially, as fabrication process of silicon image sensor has been progressed, amplitude-modulated continuous wave (AMCW) time-of-flight (ToF) cameras have been widely used due to their relatively cheap price and high measurement accuracy. However, to estimate ToF, reflected laser signal should be sequentially demodulated using optoelectronic device such as demodulation pixel, which induces relatively

Experimental microdosimetry along with the microdosimetric kinetic (MK) model can be utilized to predict the biological effects of ions. To predict the relative biological effectiveness (RBE) of ions and the survival fraction (SF) of human salivary gland tumour (HSGc-C5) cells, microdosimetric quantities measured by a silicon-on-insulator (SOI) MicroPlus-mushroom microdosimeter along the spread-out Bragg peak (SOBP) delivered by pencil beam scanning of 4He, 12C, 16O, and 20Ne ions were used. The

In this study, we investigate the performance of the Gunma University Heavy Ion Medical Center's ion computed tomography (CT) system, which measures the residual range of a carbon-ion beam using a fluoroscopy screen, a charge-coupled-device camera, and a moving wedge absorber and collects CT reconstruction images from each projection angle. Each 2D image was obtained by changing the polymethyl methacrylate (PMMA) thickness, such that all images for one projection could be expressed as the depth

Korea is surrounded by the West Sea, the South Sea, and the East Sea. There are various points at which large and small rivers flow into the sea, and areas where these rivers meet the coast are vulnerable to disasters. Thus, it is necessary to study disaster prevention techniques based on coastal characteristics and the pattern of disasters. In this study, we analyzed the risk factors of disaster districts analyzed in comprehensive plans for the reduction of damage to coastal cities from storms

Abstract In order to improve the luminous efficiency in ac PDP(Plasma Display Panel), we have suggested a new bridge type sustaining electrode which makes it possible to have free alignment between front and rear panels. The luminous efficiency of the ac PDP with suggested new sustaining electrode is improved by about 28 % compared with that of conventional sustaining electrode. However, the luminance of the ac PDP with the suggested electrode is kept the same with the conventional ones.

The two-parameter-fitting method (PFM) is commonly used to calculate the stopping-power ratio (SPR). This study proposes a new formalism: a three-PFM, which can be used in multiple spectral computed tomography (CT). Using a photon-counting CT system, seven rod-shaped samples of aluminium, graphite, and poly(methyl methacrylate) (PMMA), and four types of biological phantom materials were placed in a water-filled sample holder. The X-ray tube voltage and current were set at 150 kV and 40 μA, respe

Amplitude-modulated continuous wave (AMCW) time-of-flight (ToF) sensor is widely used to capture 3D information of objects due to its relatively high measurement precision in short range. However, the measurement accuracy of AMCW ToF measurement method is generally sensitive to the reflectivity of object, internal stray light, modulation instability, and external light. Consequently, distance measurement error inevitably occurs even in indoor measurement condition. To compensate such error, a po

The errors on the stopping power ratio (SPR) of mouthpiece samples from ERKODENT were evaluated. Erkoflex and Erkoloc-pro from ERKODENT and samples that combined Erkoflex and Erkoloc-pro were computed tomography (CT)-scanned using head and neck (HN) protocol at the East Japan Heavy Ion Center (EJHIC), and the values were averaged to obtain the CT number. The integral depth dose of the Bragg curve with and without these samples was measured for 292.1, 180.9, and 118.8 MeV/u of the carbon-ion penc

The purpose of this study was to determine the dependence of the dose distribution on the width of the respiratory gating window by using radiochromic Gafchromic EBT2 film. An in-house three-dimensional breathing simulator was used with a 4-s cycle and a 3-cm movement. The gamma index and the 50, 95, and 20–80% dose distributions were individually analyzed with regard to static, 100 (full motion), 60, 40, 30, 20, and 15% respiratory gating windows. In addition, dose differences based on the diff