• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.7
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• pp.65-70
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• 2012

In this paper, a compact UWB (Ultra Wideband) BPF(Band-Pass Filter) with dual notched bands is proposed using a hybrid Composited Right-Left Handed (CRLH) and Defected Ground Structure (DGS). To avoid the interferences such as Wireless LAN (Center frequency: 2.4GHz and 5.8GHz), the CRLH is employed to obtain the dual notched bands and the DGS is used to obtain the wide stop-band above the pass-band. The fabricated filter has good performance and has more than 30dB rejection at the center frequency of 2.4 GHz and 5.8GHz. The dual notched bands are easily movable by changing the CRLH parameter. Also the insertion loss is less than 0.4dB in the lower pass-band and 0.7dB in the upper pass-band, and it has small group delay variation less than 0.6ns. The size of the fabricated filter is very compact (17mm*17mm).

• Korean Journal of Crystallography
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• v.13 no.1
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• pp.21-24
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• 2002

The crystal structure of cholesteryl crotonate was investigated by X-ray diffraction. Crystallo-graphic data for the title compound: P2₁, a = 13.446(4) , b = 11.802(3) , c = 18.782(5) , β = 103.99(2)°, Z = 4. Reflections were collected with an Enraf-Nonius CAD-4 diffractometer equipped with a graphite monochromator. The structure was solved by direct methods and refined by least-squares analyses. The final R value was 0.092 for 1604 reflections. The cholesterol fragment of the title compound were in good agreement with those for related cholesterol derivatives. The molecules were stacked in clearly separated layers. At the center of the layers, there were cholesterol-cholesteryl interactions between the symmetry-related A molecules and the cholesteryl-C(17) side chain of B molecules. There were also interactions between the C(17) side chain of A molecules and the crotonate chains off and B molecules in the interface region between layers. The crystal structure of the title compound turned out to be isostructural with those of cholesteryl ethylcarbonate, cholesteryl propylcarbonate, and cholesterol crotylcarbonate. The crystals show the liquid crystalline state having the cholesteric phase.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.685-690
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• 2013

This paper has proposed a multi-channel and wide gain-range baseband circuit blocks for the IEEE 802.15.4g MR-OFDM SUN systems. The proposed baseband circuit blocks consist of two negative-feedback VGAs, an active-RC 5th-order chebyshev low-pass-filter, and a DC-offset cancellation circuit. The proposed baseband circuit blocks provide 1 dB cut-off frequencies of 100 kHz, 200 kHz, 400 kHz, and 600 kHz respectively, and achieve a wide gain-range of +7 dB~+84 dB with 1 dB step. In addition, a DC-offset cancellation circuit has been adopted to mitigate DC-offset problems in direct-conversion receiver. Simulation results show a maximum input differential voltage of $1.5V_{pp}$ and noise figure of 42 dB and 37.6 dB at 5 kHz and 500 kHz, respectively. The proposed I-and Q-path baseband circuits have been implemented in $0.18-{\mu}m$ CMOS technology and consume 17 mW from a 1.8 V supply voltage.

• The Korean Nurse
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• v.17 no.1 s.93
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• pp.14-17
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• 1978

• 한국초전도학회:학술대회논문집
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• 2008.08a
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• pp.17-17
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• 2008

• Bulletin of the Korean Chemical Society
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• v.17 no.3
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• pp.212-214
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• 1996

• Journal of Nutrition and Health
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• v.37 no.3
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• pp.176-181
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• 2004

This study was designed to investigate the effects of buthanol (BuOH) fraction of pine (Pinus densiflora Sieb et Zucc) needle on cholesterol and lipofuscin (LF) accumulations, acetylcholine (ACh) and its related enzyme activities such as choline acetyltransferase (CAhT) and acetylcholinesterase (AChE), and monoamone oxidase-B (MAO-B) activity, which destroyed the catecholamine-related neurotransmitters in brain membranes of Sprague-Dawley (SD) rats. Male SD rats were fed basic diets (control group) or experimental diets (BuOH-25, BuOH-50 and BuOH-100) for 45 days. Cholesterol accumulations in mitochondria and microsomes were significantly inhibited (about 14 - 17％ and 23 - 34％, respectvely) in BuOH-50 and BuOH-100 groups, whereas LF levels were significantly inhibited (about 10 - 14％) in BuOH-50 and BuOH-100 groups compared with control group. ACh levels and ChAT activities were significantly increased (about 11 - 17％ and 11 - 23％, respectively) in membranes of BuOH-50 and BuOH-100 groups compared with control group. AChE activities were significantly increased (about 14 - 17％) in membranes of BuOH-50 and BuOH-100 groups. There was no significant difference in MAO-B activities between control and experimental diet groups. The results suggest that butanol fraction of pine needle may play an effective role in an antiaging effect and improving a learning and memory impairments.

• Biomedical Science Letters
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• v.13 no.3
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• pp.213-221
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• 2007

This study was designed to investigate the correlation between the expression rate of p53 and p21 proteins, c-erbB-2 oncoprotein and $TGF-{\beta}1$ and tumor prognostic factors in colon cancer including the tumor size, histological differentiation and Dukes' stage. The expression rate of p53 protein was 11.4% (4 cases) at well differentiation, 48.6% (17 cases) at moderately differentiation, and 17.1% (6 cases) at poorly differentiation. In other words, the poorer differentiation, the higher the expression rate of p53 protein (P<0.05). The expression rate of p21 protein was 17.1% (6 cases) at well differentiation, 40.0% (14 cases) at moderately differentiation, and 8.6% (3 cases) at poorly differentiation, indicating that, as the histological malignant degeneration progressed, the expression rate of p21 protein decreased distinctively (P<0.05). However, the correlation of the above mentioned proteins with tumor size and Dukes' stage was not recognized. The expression rate of c-cerbB-2 oncoprotein was 11.4% (4 cases) at well differentiation, 54.3% (19 cases) at moderately differentiation, and 17.1% (6 cases) at poorly differentiation, indicating that the poorer differentiation, the higher expression rate of c-erbB-2 oncoprotein (P<0.05). The expression rate of $TGF-{\beta}1$ was 17.1% (6 cases) at well differentiation, 48.6% (17 cases) at moderately differentiation, and 11.4% (4 cases) at poorly differentiation. As Dukes' stage progressed, the expression rate of $TGF-{\beta}1$ was 8.6% (3 cases) in stage A, 20.0% (7 cases) in stage B, 37.1 % (13 cases) in stage C, and 11.4% (4 cases) in stage D. There was a difference in expression rates between Dukes' stages (P<0.05). In 10 cases, p53 protein was positive while p21 protein was negative, and in 6 cases, p53 protein was negative whereas p21 was positive (P<0.05). Therefore, a statistically significant inverse correlation between the expression rate of p53 protein and that of p21 protein was observed. In conclusion, since there was a signigicant correlation between histological differentiation of colon cancer and the expressions of p53 and p21 proteins and c-erbB-2 oncoprotein, and between Dukes' stage and the expression of $TGF-{\beta}1$, it was conformed that the overexpression of p53 and p21 proteins, c-erbB-2 oncoprotein, and $TGF-{\beta}1$ is closely associated with the occurrence of colon cancer and its progress. Accordingly, this study may be greatly beneficial to the presumption of diagnosis, treatment and prognosis of colon cancer patients.

• Korean Architects
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• no.7 s.435
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• pp.16-17
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• 2005

• Progress in Superconductivity and Cryogenics
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• v.17 no.3
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• pp.1-4
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• 2015

Production of $MgB_2$ film on metallic Hastelloy with SiC as the buffer layer was achieved by means of hybrid physical-chemical vapor deposition technique, whereas SiC buffer layers with varied thickness of 170 and 250 nm were fabricated inside a pulsed laser deposition chamber. Superconducting transition temperature and critical current density were verified by transport and magnetic measurement, respectively. With SiC buffer layer, the reduced delaminated area at the interface of $MgB_2$-Hastelloy and the slightly increased $T_c$ of $MgB_2$ tapes were clearly noticed. It was found that the upper critical field, the irreversibility field and the critical current density were reduced when $MgB_2$ tapes were buffered with SiC buffer layer. Clarifying the mechanism of SiC buffer layer in $MgB_2$ tape in affecting the superconducting properties is considerably important for practical applications.