• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.5-9
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• 1996

As optical massmemories, (Se, S)-based chalcogenide amorphous films are used for a holographic supermicrofiche by using the refractive-index change. In 1000$\AA$thick-As$_{40}$ Ge$_{10}$Se$_{100-x}$S$_{x}$(x=0.25, 35at.%), the amount of refractive index change $\Delta$n reaches 0.01~0.53 at 6328, 7800$\AA$ by exposing for 15minutes plue-pass filtered mercury lamp(~4300$\AA$) and annealing 20$0^{\circ}C$. And in initially annealed As$_{40}$ Ge$_{10}$Se$_{15}$ S$_{35}$, photodarkening(PD) and thermalbleaching(TB) was founded.ded.B) was founded.d.

• Electrical & Electronic Materials
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• v.10 no.5
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• pp.467-472
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• 1997

In this study, we investigated the thickness dependence of thermal bleaching(TB) effect as well as photo-induced scalar phenomena, such as photodrakening(PD) effect and photorefraction(PR) change, in chalcogenide A $s_{40}$ G $e_{10}$S $e_{15}$ $S_{35}$ thin films. We found that when these films were exposed for 15 minutes using blue-pass filtered Hg lamp(~4300$\AA$) after annealing for 30 minutes around the glass transition temperature Tg(20$0^{\circ}C$), the refractive index change ($\Delta$n) was varied up to 0.02~0.46 according to each thickness condition and the optical energy gap ($\Delta$ $E_{op}$ ) was shifted to a longer wavelength of approximately 0.67eV, especially for 1000$\AA$-thickness. Also, the TB PD effects have been understood by the results related to optical absorption characteristics. The TB effect could be estimated as increasing the stabilization of amorphous chalcogenide films since absorption slope of extended regions(U) was not changed by annealing. On the other hand, the PD effect could be understood as due to the enhancement of disorder since U and the slope of Urbachs tail(1/F) around an absorption edge were decreased by exposing.ing.n edge were decreased by exposing.

• Journal of the Korean Vacuum Society
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• v.7 no.1
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• pp.24-28
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• 1998

Pd/Ge ohmic contact system on n-type InGaAs was studied. A good ohmic begavior by rapid thermal annealing was shown up to $400^{\circ}C$, and the specific contact resistance was reduced to low-$10^-6\Omega\textrm{cm}^2$EX>. However, above $425^{\circ}C$ it was deteriorated by intermixing and phase reaction of ohmic metals and InGaAs substrate. No remarkable phase change was observed below $350^{\circ}C$, but the reaction was initiated at ~$375^{\circ}C$ and considerable phase change was found above $425^{\circ}C$. Non-spiking and planar interfaces were observed even when annealed at $425^{\circ}C$, and smooth and shiny surface was kept up to $400^{\circ}C$.

• Journal of Nutrition and Health
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• v.41 no.7
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• pp.594-601
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• 2008

Panax ginseng C.A. Meyer (Panax ginseng) has been used for several thousand years to prolong longevity in Asian countries. Ginsenosides are the most active components isolated from ginseng and belong to damarane saponin which are separated into protopanaxadiol and protopanaxtriol. To evaluate the complex effect of ginsenoside in apo E null mice, ginseng extract were intraperioneally (i.p.) injected and provided high-cholesterol diet for 12 weeks. Ginseng extract came from were i.p. injected with dose of 100 mg/kg/day for 4 weeks in the last experimental duration. Ginseng extract used experiment was abundant Rb1, Rc, Re, and Rg1 and PD：PT ratio was 1.2. The high-cholesterol diet induced liver damage was significantly reduced by ginseng extract. Results from plasma lipid profiles and atherogenic index were improved by ginseng extracts. The GE group significantly decreased plasma TG and TC by 73% and 61% compared to apo E (-/-) group. Also ginseng extract tend to decrease lipid profiles and lipidperoxidation contents in liver and heart. Ginseng extract with an abundant amount of Rg1 significantly suppressed the apoptosis induction of cardiac tissue. In conclusion, ginseng extract (PD：PT = 1) was improved lipid profiles and anti-oxidant effects.

• Progress in Medical Physics
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• v.10 no.1
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• pp.33-40
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• 1999

Purpose: To simulate and measure the signal intensity of various tissues near bone interface in 2D and 3D neurological MR images. Materials and Methods: In neurological proton density (PD) weighted images, every component in the head including cerebrospinal fluid (CSF), muscle and scalp, with the exception of bone, are visualised. It is possible to acquire images in 2D or 3D. A 2D fast spin-echo (FSE) sequence is chosen for the 2D acquisition and a 3D gradient-echo (GE) sequence is chosen for the 3D acquisition. To find out the signal intensities of CSF, muscle and fat (or scalp) for the 2D spin-echo(SE) and 3D gradient-echo (GE) imaging sequences, the theoretical signal intensities for 2D SE and 3D GE were calculated. For the 2D fast spin-echo (FSE) sequence, to produce the PD weighted image, long TR (4000 ms) and short TE$_{eff}$ (22 ms) were employed. For the 3D GE sequence, low flip angle (8$^{\circ}$) with short TR (35 ms) and short TE (3 ms) was used to produce the PD weighted contrast. Results: The 2D FSE sequence has CSF, muscle and scalp with superior image contrast and SNR of 39 - 57 while the 3D GE sequence has CSF, muscle and scalp with broadly similar image contrast and SNR of 26 - 33. SNR in the FSE image were better than those in the GE image and the skull edges appeared very clearly in the FSE image due to the edge enhancement effect in the FSE sequence. Furthermore, the contrast between CSF, muscle and scalp in the 2D FSE image was significantly better than in the 3D GE image, due to the strong signal intensities (or SNR) from CSF, muscle and scalp and enhanced edges of CSF. Conclusion: The signal intensity of various tissues near bone interface in neurological MR images has been simulated and measured. Both the simulation and imaging of the 2D SE and 3D GE sequences have CSF, fat and muscle with broadly similar image intensity and SNR's and have succeeded in getting all tissues about the same signal. However, in the 2D FSE sequence, image contrast between CSF, muscle and scalp was good and SNR was relatively high, imaging time was relatively short.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.399-421
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• 1996

(1) The solute distribution mechanism was analyzed for the Si0.95Ge0.05 single crystal fiber by u-PD method. (2) The steady-state solutions were obtained for the molten zone and the capillary zone. (3) The effect of the convection in the molten zone on partitioning was not significant for many cases. (4) Intermediate transient rise of Ge was shown by the sudden change of the growth velocity or molten zone height. (5) Periodic compositional modulation can be designed by using the intermediate transient.

• Proceedings of the Korean Vacuum Society Conference
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• 1996.02a
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• pp.21-22
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• 1996

• Journal of Life Science
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• v.21 no.11
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• pp.1518-1525
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• 2011

Sorafenib is the only approved systemic, therapeutic agent for hepatocellular carcinoma (HCC). The use of Ginseng Extract (GE) in cancer patients is growing worldwide; however, drug interaction between sorafenib and GE has not been illuminated. Four different human cancer cell lines including HepG2 were used and immunocompetent mice were implanted subcutaneously with a mouse HCC cell line. Treatment with low dose GE stimulated cell growth, while a high dose inhibited growth. pERK (phosphorylation of extracellular signal-regulated kinase) was concomitantly increased and decreased respective of different doses of GE. Antitumoral effect of sorafenib decreased in non-proliferating phase cells but was sensitized after low dose GE (LDG) treatment. PD98059 (ERK phosphorylation inhibitor) efficiently blocked ERK phosphorylation, resulting in loss of sorafenib sensitization even after LDG treatment. In the HCC mouse model, LDG alone slightly increased tumor size while sorafenib alone significantly decreased it. However, a combination of LDG and sorafenib significantly decreased tumor size compared with sorafenib alone. Increase of pERK was observed in some normal mice organs and mild inflammatory change was observed in some of these organs, suggesting pERK activation by LDG may cause unexpected toxicity in normal cells. GE, dose-dependently, induced stimulation or inhibition in some human cancer cell lines. Combinational use of GE and sorafenib possibly potentiated an antitumoral response to sorafenib. pERK level has been provided as a potential predictive marker for sorafenib. Our result may suggest GE's dual effects in relation to pERK level in HCC cancer cell lines, and that certain doses of GE can sensitize sorafenib.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.231-236
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• 1997

To improve electrical properties and uniformity of high-low doped n-type GaAs, new ohmic contacts with a low-resistance and the superior uniformity was developed using a concept of hybrid ohmic contact. The hybrid ohmic contact displayed good surface and interface morphology and had minimum contact resistivity of 3${\times}$10-6 $\Omega$$\textrm{cm}^2$ in a wide annealing temperature ranged from 340$^{\circ}C$ to 420$^{\circ}C$, which was much wider than that of conventional ohmic contacts. The microstructural analysis showed that the Pd/Ge ohmic contact at low annealing temperature (∼300$^{\circ}C$) and also annealing temperature (∼400$^{\circ}C$), resulting ij hybrid ohmic contacts.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.31-34
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• 1997

A reversible scalar phenomena in amorphous As$_{40}$ Ge$_{10}$ Se$_{15}$ S$_{35}$ have been investigated by blue-pass-filtered Hg lamp and He-Ne laser. Annealing causes the shift of the absorption edge to shelter wavelengths approximately 0.17ev, also illumination moves it to longer wavelengths about 0.05 ~ 0.07eV and it increases the refractive index maximum 0.3. Therefore the thermalbleaching(TB) and photodarkening(PD) effects have been understood by the results related to optical absorption characteristics. TB could be estimated as increasing the stabilization of amorphous chalcogenide films since absorption slope of extended regions(U) was not changed by annealing. On the other hand, PD could be understood as due to the enhancement of disorder since the slope of Urbach’s tail(1/F) around an absorption edge were decreased by illumination.ion.n.