• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.328-329
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• 2012

$SF_6$ gas는 반도체 및 디스플레이 제조공정 중 Dry etch과정에서 널리 사용되는 gas로 자연적으로 존재하는 것이 아닌 사용 목적에 맞춰 인위적으로 제조된 gas이다. 디스플레이 산업에서 $SF_6$ gas가 사용되는 Dry etch 공정은 주로 ${\alpha}$-Si, $Si_3N_4$ 등 Si계열의 박막을 etch하는데 사용된다. 이러한 Si 계열의 박막을 식각하기 위해서는 fluorine, Chlorine 등이 사용된다. fluorine계열의 gas로는 $SF_6$ gas가 대표적이다. 하지만 $SF_6$ gas는 대표적인 온실가스로 지구 온난화의 주범으로 주목받고 있다. 세계적으로 온실가스의 규제에 대한 움직임이 활발하고, 대한민국은 2020년까지 온실가스 감축목표를 '배출전망치(BAU)대비 30% 감축으로' 발표하였다. 따라서 디스플레이 및 반도체 공정에는 GWP (Global warming Potential)에 적용 가능한 대체 가스의 연구가 필요한 상황이다. 온실가스인 $SF_6$를 대체하기 위한 방법으로 GWP가 낮은 $C_3F_6$가스를 이용하여 $Si_3N_4$를 Dry etching 방법인 RIE (Reactive Ion Etching)공정을 한 후 배출되는 가스를 측정하였다. 4인치 P-type 웨이퍼 위에 PECVD (Plasma Enhanced Chemical Vapor Deposition)장비를 이용하여 $Si_3N_4$를 200 nm 증착하였고, Photolithography공정을 통해 Patterning을 한 후 RIE공정을 수행하였다. RIE는 Power : 300 W, Flow rate : 30 sccm, Time : 15 min, Temperature : $15^{\circ}C$, Pressure : Open과 같은 조건으로 공정을 수행하였다. 그리고 SEM (Scanning Electron Microscope)장비를 이용하여 Etching된 단면을 관찰하여 단차를 확인하였다. 또한 Etching 전후 배출가스를 포집하여 GC-MS (Gas Chromatograph-Mass Spectrophotometry)를 측정 및 비교하였다. Etching 전의 경우에는 $N_2$, $O_2$ 등의 가스가 검출되었고, $C_3F_6$ 가스를 이용해 etching 한 후의 경우에는 $C_3F_6$ 계열의 가스가 검출되었다.

• Journal of Sericultural and Entomological Science
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• v.45 no.1
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• pp.25-30
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• 2003

This study was carried out to investigate active constituents of Bombysis corpus on the neurite outgrowth from PC 12 cells led to isolate three new and a known sphingolipids from the n-hexane soluble portion and five amines from the butanol soluble portion of its methanol extract. On the basis of spectroscopic data, their structures have been elucidated as (4E,6E,2S,3R)-2-N-eicosanoyl-4,6-tetradecasphingadienine, (4E,2S,3R)-2-N-eicosanoyl-4-tetradecasphingenine,(4E,6E,2S,3R)-2-N-docosanoyl-4,6-tetradecasphingadienine,(4E,6E,2S,3R)-2-N-docosanoyl-4,6-tetradecasphingadienine,(4E,2S,3R)-2-N-octadecanoyl-4-tetradecasphingenine, 1,7-dimethyl-xanthine, uracil, urea, betaine and tyrosine, respectively. The neurite outgrowth activities of these compounds were examined in PC12 cells by measuring the length of neurites. These compounds promoted neurite outgrowth in PC12 cells significantly.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1097-1102
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• 2007

This paper describes the development of 6-axis force/moment sensor for an intelligent robot's foot. In order to walk on uneven terrain safely, the foot should perceive the applied forces Fx, Fy, Fz and moments Mx, My, Mz to itself. The applied forces and moments should be measured from a 6-axis force/moment sensor attached to a humanoid robot's foot(ankle). They in the published paper already have some disadvantage in the size of the sensor, the rated output and so on. The rated output of each component sensor (6-axis force/moment sensor) is very important to design the 6-axis force/moment sensor for precision measurement. Therefore, each sensor should be designed to be gotten similar the rated output under each rated load. So, the sensing elements of the 6-axis force/moment sensor should get lots of design variables. Also, the size of 6- axis force/moment sensor is very important for mounting to robot's foot. In this paper, a 6-axis force/moment sensor for perceiving forces and moments in a humanoid robot's foot was developed using many PPBs (parallel plate-beams). The structure of the sensor was newly modeled, and the sensing elements (plate-beams) of the sensor were designed using FEM (Finite Element Method) analysis. Then, the 6-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements, and the characteristic test of the developed sensor was carried out. The rated outputs from FEM analysis agree well with that from the characteristic test.

• Biomedical Science Letters
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• v.8 no.3
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• pp.137-142
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• 2002

The expression of CD44v is known as a marker of cancer progression and its metastasis in colorectal cancer. It has been known that CD44 variant containing sequences encoded by exon 11 (v6) confer metastatic potential to human colorectal cancer cells. The role of CD44 standard (CD44s) and CD44v6 in colorectal cancer was investigated in this study by immunohistochemical staining of the primary tumors obtained from the colorectal cancer patients. Immunohistochemical staining was performed in 40 patients with colorectal cancer who underwent curative surgery at Keimyung University hospital. The expression CD44s and CD44v6 was observed in 24/40 (60%) and 13/40 (32.5%) respectively. The expression of CD44v6 had correlation with TNM stage (P＜0.05), however CD44s had not any correlation with clinicopathological parameters. These results suggest that CD44v6 expression may give an information for tumor progression than decreased expression of CD44s in colorectal cancer cells.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.2
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• pp.125-131
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• 2002

This paper presents MMIC drive and power amplifiers covering 6-18 ㎓. For simple wideband impedance matching and less sensitivity to fabrication variation, modified distributed topologies are employed in the both amplifiers. Cascade amplifiers with a self-biasing circuit through feedback resistors are used as unit gain blocks in the drive amplifier, resulting in high gain, high stability, and compact chip size. Self impedance matching and high-pass, low-pass impedance matching networks are used in the power amplifier. In measured results, the drive amplifier showed good return losses ($S_11,{\;}S_{22}{\;}<{\;}-10.5{\;}dB$), gain flatness ($S_{21}={\;}16{\;}{\pm}0.6{\;}dB$), and $P_{1dB}{\;}>{\;}22{\;}dBm$ over 6-18 GHz. The power amplifier showed $P_{1dB}{\;}>{\;}28.8{\;}dBm$ and $P_{sat}{\;}{\approx}{\;}30.0{\;}dBm$ with good small signal characteristics ($S_{11}<-10{\;}dB,{\;}S_{22}{\;}<{\;}-6{\;}dB,{\;}and{\;}S_{21}={\;}18.5{\;}{\pm}{\;}1.25{\;}dB$) over 6-18 GHz.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.12
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• pp.78-84
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• 2009

When external force is applied to humanoid robot's head, humanoid robot's neck is rotated to prevent the damage of it. So, robot's neck have to perceive forces (Fx of x-direction, Fy of y-direction and Fz of z-direction) and moments (Mx of x-direction, My of y-direction and Mz of z-direction) using the attached 6-axis force/moment sensor. Thus, in this paper, 6-axis force/moment sensor was developed to sense the forces and moments applied to robot's head. The structure of 6-axis force/moment sensor was modeled newly, and it was designed using FEM software (ANSYS) and manufactured by attaching straingages on the sensing element, finally, the characteristic test of the sensor was carried out. As a result, it is confirmed that interference error is less than 3%. And, it is thought that the sensor can be used to measure the forces and the moments for humanoid robot's head.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.685-690
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• 2002

The mitogen-stimulated serine/threonine kinase $p70^{S6k}$ plays an important role in the progression of cells from $G_0/G$_1$$ to S phase of the cell cycle by translational up-regulation of a family of mRNA transcripts family of mRNA transcripts which contain polypyrimidine tract at their 5 transcriptional start site. Here, we report that $p70^{S6k}$ was constitutively phosphorylated and activated to various degrees in serum-deprived AGS, A2058, HT-1376, MG63, MCF7, MDA-MB-435S, MDA-MB-231 and MB-157. Rapamycin treatment induced a significant dephosphorylation and inactivation of $p70^{S6k}$ in all cancer cell lines, while wortmannin, a specific inhibitor of PI3-K, caused a mild dephosphorylation of $p70^{S6k}$ in AGS, MDA-MB-435S and MB-157. In addition, SQ20006, methylxanthine phosphodiesterase inhibitor, reduced the phosphorylation of $p70^{S6k}$ in all cancer cells tested. Consistent with inhibitory effect of rapamycin on $p70^{S6k}$ activity, rapamycin inhibited [$^3H$]-thymidine incorporation and increased the number of cells at $G_{0}G_{1}$ phase. Furthermore, these inhibitory effects were accompanied by the decrease in growth of cancer cells. Taken together, the results indicate that the antiproliferative activity of rapamycin might be attributed to cell cycle arrest at $G_{0}G_{1}$ phase in human cancer cells through the inhibition of constitutively activated $p70^{S6k}$ of cancer cells and suggest $p70^{S6k}$ as a potential target for therapeutic strategies aimed at preventing or inhibiting tumor growth.

• Journal of Oral Medicine and Pain
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• v.45 no.4
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• pp.89-96
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• 2020

Purpose: To investigate the expression of malondialdehyde (MDA), lipid peroxidation marker for oxidative stress (OS), in autoimmune Sjögren's syndrome (SjS) by utilizing the SjS-prone C57BL/6.NOD-Aec1Aec2 (B6DC) mouse and the SjS patient plasma samples. Methods: The MDA concentrations in the lysates of the submandibular gland, liver, and serum samples from the SjS-prone B6DC mouse model were compared with those from the C57BL/6J as a control. A thiobarbituric acid reactive substance (TBARS) assay kit was used to measure MDA. Plasma samples from five SjS patients and five control subjects were also evaluated. Results: The MDA concentrations in experimental animals and controls were not significantly different. There were no significant differences between the plasma of SjS patients and of controls. Conclusions: The expression of MDA was investigated in the organs from the SjS-prone B6DC mouse for the first time and in the plasma samples of SjS patients. No significant differences were observed between SjS and control samples when MDA was the target molecule with the TBARS assay. MDA may not be a reliable marker to measure OS contrary to the published studies involving OS of SjS.

• 한국전산유체공학회:학술대회논문집
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• 2008.08a
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• pp.35.6-35.6
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• 2008

• The Korean Nurse
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• v.15 no.2 s.82
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• pp.70-78
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• 1976