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Study of Gain Improvement in a Low Noise Amplifier
Ju-HoSon,Dong-YongKim 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.43 No.1
We design a high-gain low noise amplier (LNA) by applying a 0.25 m CMOS process for Bluetooth. Using a cascade inverter, we design a one-stage amplier that uses a reference power supply without a choke inductor. An existing one-stage LNA was an improved structure having a low power gain of 10 15 dB. The designed 2.4-GHz LNA has a noise gure (NF) of 2.2 dB and a high power gain of 21 dB.
Synthesis, Cytotoxicity and Antitumor Activity of 2,3-Diarylcyclopent-2-ene-1-ones
Nguyen-HaiNam,YongKim,Young-JaeYou,Dong-HoHong,Hwan-MookKim,Byung-ZunAhn 대한약학회 2002 Archives of Pharmacal Research Vol.25 No.5
The present study was done to determine the effect of trolox C, a hydrophilic analogue of vitamin E, on hepatic injury, especially the alteration in cytochrome P-450 (CYP)-dependent drug metabolism during ischemia and reperfusion (I/R). Rats were subjected to 60 min of hepatic ischemia and 5 h of reperfusion. Rats were treated intravenously with trolox C (2.5 mg/kg) or vehicle (PBS, pH 7.4), 5 min before reperfusion. Serum alanine aminotransferase and lipid peroxidation levels were markedly increased after I/R. This increase was significantly suppressed by trolox C. Cytochrome P-450 content was decreased after I/R but was restored by trolox C. There were no significant differences in ethoxyresorufin O-dealkylase (CYP 1A1) and methoxyresorufin O-dealkylase (CYP 1A2) activities among any of the experimental groups. Pentoxyresorufin O-dealkylase (CYP 2B1) activity was decreased and aniline p-hydroxylase (CYP 2E1) activity was increased after I/R. Both these changes were prevented by trolox C. Our findings suggest that trolox C reduces hepatocellular damage as indicated by abnormalities in microsomal drug-metabolizing function during I/R, and that this protection is, in part, caused by decreased lipid peroxidation.
Synthesis and Cytotoxicity of Some Rigid Derivatives of Methyl 2,5-Dihydroxycinnamate
Nguyen-HaiNam,YongKim,Young-JaeYou,Dong-HoHong,Hwan-MookKim,Byung-ZunAhn 대한약학회 2002 Archives of Pharmacal Research Vol.25 No.5
Four flavonoid glycosides, flavaprin (7), evodioside B (8), vitexin (11), and hesperidin (12), as well as the coumarins bergapten (1), xanthotoxin (2), and isopimpinellin (3), the lignan simplexoside (10), the steroids b-sitosterol (4) and daucosterol (5), the limonoids isolimonexic acid (6) and limonin (9), and uracil (13) and myo-inositol (14) have been isolated from Euodia daniellii. The structures of these compounds were established from spectral data. Among the isolates, bergapten showed cyclooxygenase-2 inhibitory activity with an IC50 value of 6.2 mg/ml. Flavonoids isolated from this plant exhibited no cytotoxic activity against the human tumor cell lines, A549, SKOV-3, SKMEL-2, XF498, and HCT15.