• Resources Recycling
• /
• v.13 no.2
• /
• pp.24-32
• /
• 2004

Solvent extraction equilibria of Gd with PC88A from chloride solutions were analyzed by considering chemical equilibria. phase equilibria, mass and charge balance equations. The following solvent extraction reaction and equilibrium constant were evaluated from the experimental data performed in this study. $Gd^{3+}$ $+2H_2$$A_2$,$or=GdA_3$HA.or+3 $H^{+}$ , K=3.3 A procedure was suggested to calculate the initial concentration of chloride ion from initial pH and initial concentration of Gd. By applying ionic equilibria, the distribution of Gd complexes with Gd and HCl concentration was obtained. The predicted distribution coefficients of Gd agreed well with the experimental results.

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2005.05a
• /
• pp.28-32
• /
• 2005

본 연구는 Karr column을 이용한 희토류원소의 분리에 대한 기초 연구로서, 수상의 초기 pH와 유기상 중 PC-88A의 비누화도에 따른 Nd, Sm의 분리특성을 파악하였다. 실험결과 pH $0.8{\sim}2.3$ 범위에서 PH가 높아짐에 따라 Nd, Sm의 추출율 및 분리계수가 증가하였으며, PC-88A 비누화도 40%인 조건에서 추출 후 수상의 초기 PH에 관계없이 평형 pH가 약 1.5 정도로 유지되는 것을 알 수 있었다. 그리고 PC-88A 비누화도가 증가함에 따라 Nd, Sm의 추출율이 크게 증가하였으며, 비누화도 40%인 조건에서 가장 높은 분리계수(${\beta}_{Sm,\;Nd}\;=\;10.8$)를 보여 주었다.

• Journal of Pharmaceutical Investigation
• /
• v.29 no.4
• /
• pp.349-353
• /
• 1999

A novel polymeric tablet of tinidazole (TD) was formulated to treat Helicobacter pylori and Giardia lambria more efficiently with reduced hepatotoxicity by controlling the release of TD after oral administration. TD tablets containing various concentrations of either xanthan gum (XG, viscosity enhancer) and/or polycarbophil (PC, mucoadhesive) were prepared by the wet granulation method. In vitro release of TD into pH 2.0 and pH 5.0 buffer solutions was observed at 37°C by using an USP dissolution tester and an UV (313 nm) spectrophotometer. In vivo absorption of TD tablets was investigated in rabbits by measuring the blood concentration of TD after oral administration using a HPLC. Compared to a commercial TD tablet, in vitro release of TD in both pH 2.0 and pH 5.0 buffer solutions significantly decreased as the concentration: of XG or PC in the tablet increased up to 30%. However, when XG and PC was added in combination, TD was completely released in a pH 5.0 buffer solution within 8 hours, whereas the release of TD in pH 2.0 buffer solution significantly decreased. TD in a commercial tablet was rapidly absorbed after oral administration in rabbits. After oral administration of the polymeric tablets that contain both XG and PC, plasma concentration of TD dramatically decreased. Since the oral absorption of TD significantly decreased by the addition of XG and PC in the tablets while TD completely released in a pH 5.0 buffer solution, it was speculated that more TD was retained in the gastrointestinal tract. Thus, it was possible to control the release of TD by changing the content of XG and/or PC in the tablet, thereby manipulating the release rate and the gastrointestinal retention of TD after oral administration in rabbits.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2004.11a
• /
• pp.103-106
• /
• 2004

본 논문에서는 PC 기반 지상파 DMB(Terrestrial Digital Multimedia Broadcasting, T-DMB) 수신기를 위한 SW 최적화에 대해 설명한다. 이 수신기는 PC 외부에 지상파 DMB 신호를 안테나로 수신하여 복조하고 채널 복호하는 프론트 엔드(front-end) 수신 모듈을 이용, USB를 통하여 RS(Reed-Solomon) 부호화된 MPEG-2 TS(Transport Stream) 데이터를 읽어 들여 RS 복호, TS 역다중화, 비디오 복호, 오디오 복호 등의 SW 처리 과정을 거쳐 디스플레이 상에 수신 내용을 표시하게 된다. 본 논문에서는 저사양 PC에서도 T-DMB를 수신할 수 있도록 H.264/MPEG-4 AVC(Advanced Video Coding) 복호 과정을 최적화한 결과에 대해 설명한다.

• Journal of fish pathology
• /
• v.17 no.2
• /
• pp.131-137
• /
• 2004

In the present study, phosphatidylcholine (PC) hydrolyzing enzyme had been isolated from membrane of flounder liver. PC hydrolyzing enzyme solubilized in 1% Triton X -100 from membrane was partially purified by sequential chromatography on Heparin Sepharose CL-6B and Heparin-5PW columns. The products by membrane-bound hydrolyzing enzyme were identified as phosphatidic acid and choline, but in the presence of primary alcohol, phosphatidylethanol was produced at the expense of phosphatidic acid. These data suggest that membrane-bound enzyme may be a PC-phosphoipase D (PLD) type. The enzyme had pH optimum at below 6.0 and temperature optimum at $37^\circ{C}$. The activity of PC-PLD was dose-dependently increased by $Ca^{2+}$ but not $Mg^{2+}$. The activity of PC-PLD was stimulate by PC, PIP2 and PE.

• Proceedings of the Korean Biophysical Society Conference
• /
• 1998.06a
• /
• pp.32-32
• /
• 1998

The effect of neurotensin (NT) was investigated in rat pheochromocytoma (PC12) cells. When PC12 cells were treated with micromolar concentrations of NT, [$^3$H]norepinephrine ([$^3$H]NE) secretion and elevation of cytosolic Ca$\^$2＋/ concentration ([Ca$\^$2＋/]i) were evoked in a concentration-dependent manner with an EC$\sub$50/ of 50 ${\mu}$M.(omitted)

• Applied Biological Chemistry
• /
• v.50 no.1
• /
• pp.63-67
• /
• 2007

The neuroprotective effect of methanolic extracts from Dendrobium nobile Lindl. (DME) against $H_{2}O_{2}$-induced neurotoxicity in PC12 cells was investigated. The treatment of PC12 cells with various DME concentrations under $H_{2}O_{2}$ resulted in the induction of protective effect in a dose-dependent manner, as determined by the results of an MTT reduction assay, an LDH release assays, and a morphological assay. Interestingly, we also detected reduction of apoptotic bodies and inhibition of caspase-3 activity by DME in $H_{2}O_{2}$-indeced PC12 cells. These data show that the neuroprotective effect of DME against PC12 cells might be related to the suppression of caspase-3 activation. Therefore, these results suggest that DME could be a new potential candidate as chemotherapeutic agents against neuronal diseases.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.7
• /
• pp.85-93
• /
• 1995

In this study, phthalocyanine thin films were prepared by vacuum sublimation method and investigated sensing characteristics of the films. The phthalocyannies used for the prepaation of the NO$_{x}$ sensors were metal-free Pc(H$_{2}$Pc) and metal Pc(CuPc, CoPc, PbPc). And the substrate temperatures maintained during the fomation of Pc films were varied between R.T. and 200$^{\circ]C$, and the base pressure was 5${\times}10^{6}$ torr. The relationships between NO$_{2}$ sensing properties and SEM analyses as a function of substrate temperatures during the formation of the films were investigated. Among the Pc films, PbPc film showed the best sensing characteristics. Particularlly, the PbPc films prepared at 70$^{\circ]C$ of the substrage temperature showen good sensitivity of 85% to 1ppm NO$_{2}$ gas at operating temperature 190$^{\circ]C$ and response time was about 24 seconds.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.17 no.6
• /
• pp.1433-1440
• /
• 2003

This research was performed to investigate protective effect of Sophorae subprostratae Radix and each fractions against ischemic damage using PC12 cells. To observe the protective effect of Sophorae subprostratae Radix on ischemia damage, vibility and changes in activities of Superoxide dismutase (SOD), Glutathione Peroxidase (GPx), Catalase and Production of Malondialdehyde (MDA) were observed after treating PC12 cells with Sophorae subprostratae Radix during ischemic insult. Groups were divided into five groups: no treated (Normal), hypoxia chamber for 48hrs followed by 6h at normoxic chamber (H/R), Sop horae subprostratae Radix total phase treated group with H/R (Total), Sophorae subprostratae Radix water phase treated group with H/R (Water), Sophorae subprostratae Radix BuOH phase treated group with H/R (BuOH), Sophorae subprostratae Radix alkaloid phase treated group with H/R (Alkaloid). The results showed that (1) in hypoxiajreperfusion model using PC12 cell, the Sophorae subprostratae Radix has the protective effect against ischemia in the dose of 0.2 ㎍/㎖, 2 ㎍/㎖ and 20 ㎍/㎖, (2) Sophorae subprostratae Radix increased the activities of glutathione peroxidase and catalase. (3) the activity of Superoxide Diamutase(SOD) increased by ischemic damage, which might represent the self protection. This study suggests that Sophorae subprostratae Radix has neuroprotective effect against neuronal damage following hypoxiajreperfusion cell culture model using PC12 cell and dose dependency effects. In conclusion, Sophorae subprostratae Radix has protective effects against ischemic oxidative damage at the early stage of ischemia.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.6 no.1
• /
• pp.7-22
• /
• 2000

The purpose of this study was to identified the level of the exposure to the PC Pornography and what's their post-exposure reactions to the PC pornography. The subjects were 423 middle school boys in Pusan. The survey was executed from July 12 through October 30, 1999. The collected data were analyzed by SPSS WIN using the %, mean, ANOVA. The results of this study were as follows: 1. 79.4%(336 boys) were exposed to the PC pornography. 46.3%(196 boys) answered that they experienced the published pornography prior to the PC pornography. 2. 78.5%(333 boys) answered that they had their PC in their homes. This ratio revealed the higher level of possession. 67.6% said that their PC were set in their own rooms. 57.9% of the subject answered they experienced the Internet Communications. 68.6% of the subject said that they tried PC communications once or twice in a week. 38.5% of the subject expressed that they used their own PC for 1-2 hours in a day. Most of them(82.7%) enjoyed the PC games or entertainment programs. 81.3% of the subject answered that their school performance didn't show the progress after the use of their own PC. 78.3% of the subject answered that they acquired information. 45.2% of the subject answered that they made their friend through the Internet communications. 78.7% of the subject answered that the time of family dialogue decreased. 70.7% of the subject answered that the time of their TV watching decreased. 3. As for their post-exposure reactions the subject who were exposed to the PC Pornography showed the point 2.93 in the item 'pleasure'. The point of 'sexual impulses' was 2.81. But the point of 'anxiety' was 2.75, the point of 'dislike or disgust' was 2.62, the point of 'guilty' was 2.59. 4. According to the frequency, the motivation and the companionship on the exposure to PC Pornography, their post-exposure reaction scores showed differences significantly. Finally, the post-exposure reaction had relation to the frequency, the motivation, the companionship and the place (F=3.28 ~ 8.40, p=.012 ~ .000).