• Title/Summary/Keyword: PC5

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Inhibitory Effects of Noscapine on Dopamine Biosynthesis in PC12 cells

  • Shin, Jung-Soo;Lee, Sang-Sun;Lee, Myung-Koo
    • Archives of Pharmacal Research
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    • v.20 no.5
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    • pp.510-512
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    • 1997
  • The effects of noscapine a phthalide isoquinoline alkaloid, on dopamine biosynthesis and tyrosine hydroxylase (TH) activity in PC12 cells were investigated. Noscapine showed 74.6% inhibition on dopamine content in PC12 cells at a concentration of $20{\mu}M.$ $IC_{50}$ of noscapine was $6.8{\mu}M.$ TH activity was inhibited by the treatment of noscapine in PC12 cells (20.9% inhibition at 20 .mu.M). Therefore, the inhibition of TH activity by noscapine might be involved in at least one component of the reduction of dopamine biosynthesis in PC12 cells.

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GOMS Analysis of Database Menu Structure for PC Communication Services (PC통신서비스를 위한 데이터베이스 메뉴 구조에 대한 GOMS 분석)

  • Yun, Cheol-Ho;No, Byeong-Ok
    • Journal of the Ergonomics Society of Korea
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    • v.19 no.1
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    • pp.101-107
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    • 2000
  • This study reviews several database menu structure for pc communication services to examine the efficiency of database menu structure. Database menu systems of 5 major pc communication companies were analyzed by GOMS methodology, a description of the knowledge that a user must have in order to carry out tasks on system. Also, each database access time of 4 pc communication companies were measured with internet pc environment in laboratory. It is recommened that another menu design strategies (for example, broad-shallow rather than narrow-deep) should be adopted because current menu structures have inefficient procedures to access those database.

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Inhibition of Glutamate-Induced Change in Mitochondrial Membrane Permeability in PC12 cells by 1-Methylated β-carbolines

  • Han, Eun-Sook;Lee, Chung-Soo
    • Biomolecules & Therapeutics
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    • v.11 no.2
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    • pp.112-118
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    • 2003
  • 1-Methylated $\beta$-carbolines (harmaline and harmalol) and antioxidants (N-acetylcysteine and ascorbate) reduced the loss of cell viability in differentiated PC 12 cells treated with 5 mM glutamate. $\beta$-Carbolines prevented the glutamate-induced decrease in mitochondrial membrane potential, cytochrome c release and caspase-3 activation in PC 12 cells. $\beta$-Carbolines reduced the formation of reactive oxygen species and depletion of glutathione due to glutamate in PC12 cells. $\beta$-Carbolines revealed a scavenging action on hydrogen peroxide and reduced the iron and EDTA-mediated degradation of 2-deoxy-D-ribose. The results suggest that I-methylated $\beta$-carbolines attenuate the cytotoxic effect of glutamate on PC12 cells by reducing the alteration of mitochondrial membrane permeability that seems to be mediated by oxidative stress.

Minimization of Pattern Size on Polycarbonate Material in V-grooving (PC 폴리머 재료의 미세 V-홈 절삭가공 시 패턴 크기 최소화)

  • Kim, Gi-Dae
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.5
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    • pp.523-527
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    • 2011
  • Polycarbonate (PC) polymer is an engineering plastic which has large tensile strength and impact resistance and is wildly used as functional parts like micro mold. Direct machining of PC materials produces lots of burrs and rough surface due to large ductility and weak heat resistance and hence it is very difficult to machine PC materials using cutting tool to make micro-parts. In this study, elliptical vibration cutting (EVC) or 2-dimensional vibration cutting was performed to minimize the size of micro V-grooves on PC material. From the experimental results, it was observed that as the cutting depth and pattern size become smaller, the better machining quality was obtained, which is attributed to the positive effect of EVC that is dependent on the ratio of vibration amplitude to cutting depth. As the height of V-groove becomes less than $1.8{\mu}m$, however, the machining quality becomes lower as the pattern size decreases.

BBS의 현황과 활성화 방안

  • Korean Associaton of Information & Telecommunication
    • 정보화사회
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    • s.17
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    • pp.26-29
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    • 1989
  • 정부는 2000년대까지 PC 1천만대를 보급한다는 방침을 세우고 공중전화의 낙전수입금을 국민학교 PC보급에 지원하는등 적극적인 정보화 추진 의욕을 보이고 있는 가운데 국민학교에서 컴퓨터교육이 실시되자 교육용PC수요 또한 최근 급격히 증가하고 있다. 지난해 국내PC시장 규모는 약 8만5천대로 지금까지 국내에 약 40만대가 보급된 것으로 추산되며 83년 붐을 일으켰던 컴퓨터 수요도 재현될 전망이다. 이렇듯 PC보급이 가속화되고 PC통신이 활성화 될 수 있는 제반 사회적 여건이 조성되가고 있지만 PC통신의 꽃이라 할 수 있는 BBS에 대한 인식과 보급은 미미한 실정이다. 이미 미.일에서는 BBS가 대중화 단계에 접어들고 있어 우리나라에서는 이의 활성화 방안 마련이 시급한 실정이다. 따라서 이번호에 국내에 소개된 몇 편 안되는 자료를 바탕으로 BBS에 대한 개념 및 개괄적인 사항을 다뤄보고자 한다.

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PC-766B' and PC-766B, 16-Membered Maerolide Angiogenesis Inhibitors Produced by Nocardia sp. RK97-56

  • Ko, Hack-Ryong;Kakeya, Hideaki;Yoshida, Arika;Onose, Rie;Ueki, Masashi;Muroi, Makoto;Takatsuki, Akira;Matsuzaki, Hiroshi;Osada, Hiroyuki
    • Journal of Microbiology and Biotechnology
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    • v.12 no.5
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    • pp.829-833
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    • 2002
  • Angiogenesis is an essential event in a variety of physiological and pathological processes. Therefore, effective inhibition of this event is a promising strategy for treating angiogenesis-related diseases, including cancer. The current study investigated two unique bafilomycin-type macrolide inhibitors of angiogenesls, PC-766B' (1) and PC-766B (2). The strain RK97-56 which produced the inhibitors was identified as Nocardia sp. by chemotaxonomic analyses, and the purification of the inhibitors was guided by their anti-angiogenic activities. PC-766B' (1) and PC-766B (2) exhibited potent inhibitory activities towards endothelial cell migration stimulated by the vascular endothelial growth factor (VEGF).

Rheological properties and thermal degradation behaviors of sonochemically treated polycarbonate/polysiloxanes blends

  • Choi, Mi-Kyung;Kim, Yu-Bin;Kim, Ji-Hye;Kim, Hyung-Su
    • Korea-Australia Rheology Journal
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    • v.20 no.4
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    • pp.245-251
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    • 2008
  • Two polysiloxanes having different chemical structures were blended with polycarbonate (PC) under ultrasonic irradiation in solution. The polysiloxanes used were poly(methylphenyl siloxane) and vinyl-terminated poly(dimethyl siloxane). It was of primary interest to investigate the effect of polysiloxane structure on the rheological properties of PC/polysiloxane blends. It was found that a small amount (1.5 phr) of polysiloxanes greatly altered the melt viscosities and elasticity of PC. In particular, incorporation of poly(methylphenylsiloxane) led to a notable increase in elasticity with greater shear sensitivity of PC. The observed rheological behaviors of PC/polysiloxane blends were partly explained in conjunction with the tendencies found in ultrasonic degradation of polysiloxanes. Thermal stability and morphology in sonicated blends of PC/polysiloxane blends were also discussed.

Rheological properties of branched polycarbonate prepared by an ultrasound-assisted intensive mixer

  • Kim, Hyung-Su;Lee, Hoo-Seok;Lee, Jae-Wook
    • Korea-Australia Rheology Journal
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    • v.19 no.1
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    • pp.1-5
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    • 2007
  • By combining ultrasonic energy which is essential for the chain scission of polymer molecules and a multifunctional agent (MFA) having double bonds at its ends, we were able to modify the molecular structure of polycarbonate (PC) from linear to a branched structure during melt processing. The three double bonds in chain ends of MFA were expected to act as sites for trapping macroradicals of PC during the course of ultrasound-assisted mixing process. The transformation of molecular structure of PC was confirmed by the measurements of rheological properties of the modified PC. After the ultrasonic irradiation of PC together with MFA, increase in complex viscosities and shear-thinning behavior were observed. The Cole-Cole plot and measurement of extensional viscosities revealed the characteristic features of branched structure with well-defined extensional behavior which is comparable to that of a commercial branched PC.

A Study on the Effect of Various Brominated Flame Retardants and the Compatibilities Between Polymer and Flame Retardants in PC/ABS Blend System (PC/ABS 블랜드의 난연화 및 상용성에 관한 연구)

  • 이영순;전종한
    • Journal of the Korean Society of Safety
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    • v.5 no.3
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    • pp.63-68
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    • 1990
  • The effects of various brominated flame retardants were investigated in PC/ABS blend system. The compatibilities between polymers and flame retardants were expected with the solubility parameter using group contribution theory. Tetrabromobisphenol A carbonate oligomer, among the flame retardants in this experiment, has been shown good miscibility for PC and ABS, respectively. But polydibromophenylene oxide and octabromodiphenyl oxide has immiscibility. The flame retardant PC/ABS blends containning tetrabromobisphenol A carbonate oligomer have been exhibited higher mechanical properties, tensile strengths and notch Izod impact strengths, at varlous content of flame retardants, than containning other flame retardants. It could be seen that the trends of mechanical properties for the flame retardant PC/ABS blends have a good concidence with the expectation of compatibility.

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Effects of Several Oriental Medicines on Protein Kinase C Activator-Induced Production and Gene Expression of Airway Mucin and Animal Model for Airway Mucus Hypersecretion (단백질인산화효소 C 활성화제로 유도된 기도 뮤신 생성 및 유전자 발현과 점액 과분비 모델동물에 대한 수종(數種) 방제의 영향)

  • Lim, Do-Hee;Park, Yang-Chun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.6
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    • pp.1500-1508
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    • 2008
  • The author investigated whether Chwiyeon-tang(PC), Haengso-tang(PH), Jawanchihyo-san(PJ) and Gamisocheongryong-tang(PS) significantly affect both PMA-induced mucin production and MUC5AC gene expression in airway epithelial cells and sulfur-dioxide-induced airway goblet cell hyperplasia and mucus hypersecretion animal model using rat. Possible cytotoxicity of each herbal medicine was assessed by measuring the survival and proliferation rate of NCI-H292 cells. Confluent NCI-H292 cells were pretreated for 30 min in the presence of PC, PH, PJ and PS, respectively, and treated with PMA(10 $ng/m{\ell}$), to assess the effect of each herbal medicine on PMA-induced mucin production by enzyme-linked immunosorbent assay(ELISA). Effects of each herbal medicine on PMA-induced MUC5AC gene expression from the same cells were investigated. Also, hypersecretion of airway mucus and goblet cell hyperplasia were induced by exposure of rats to $SO_2$ during 3 weeks. Effects of orally-administered PC, PH, PJ and PS during 1 week on intraepithelial mucosubstances and hyperplasia of goblet cells were examined using histological analysis after staining the epithelial tissue with PAS-alcian blue. (1) PC, PJ, PS and PH did not show significant effects on the survival and proliferation of NCI-H292 cells ; (2) PC, PJ and PS significantly decreased PMA-induced mucin production from NCI-H292 cells ; (3) PC, PJ and PS significantly inhibit the expression levels of PMA-induced MUC5AC gene in NCI-H292 cells ; (4) Among PC, PJ, PS and PH, only PS decreased $SO_2$-induced hyperplasia of airway goblet cells and intraepithelial mucosubstances. This result suggests that PC, PJ and PS can not only affect the production of mucin but also affect the expression of mucin gene and this can explain, at least in part, the traditional use of PC, PJ and PS for controlling airway diseases showing hypersecretion of mucus in oriental medicine.