• Title, Summary, Keyword: CPT

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Induction of Apoptosis by Camptothecin in HL-60 Cells (HL-60 세포에서 Camptothecin의 apoptosis 유도작용)

  • 김해종;천영진;김미영
    • YAKHAK HOEJI
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    • v.43 no.3
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    • pp.385-390
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    • 1999
  • Camptothecin (CPT) has been known to induce apoptosis in various cancer cell lines. To examine the intracellular apoptotic death signal initiated by CPT, we investigated the possible connection between caspase-3 activation and GSH depletion during CPT-induced apoptosis in HL-60 cells. Treatment of cells with $1{\;}{\mu}M$ CPT induced PARP cleavage accompanied by DNA fragmentation. z-VAD-fmk, a caspase-3 inhibitor, blocked the CPT-induced DNA fragmentation. Pretreatment of cells with N-acetylcysteine, a precursor of GSH biosynthesis, failed to inhibit CPT-induced PARP celavage and DNA gragmenatation. No significant changes in GSH depletion is not essential for caspase activation during CPT-induced apoptosis. We also investigated whether CPT-induced apoptosis is associated with changes of the levels of Bax and Bcl-2, two proteins involved in the control of apoptosis. Bcl-2 levels exhibited a late decrease compared with the kinetics of DNA fragmentation, whereas Bax levels increased more rapidly after CPT treatment. These results suggest that Bax plays more important role than Bcl-2 in inducing DNA fragmentation and may function upsteam of proteolytic activation of caspase-3 pathway in CPT-induced apoptosis.

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Correlations between the CPT and the SPT for the Residual Soil in Korea (국내 잔류토층에서 CPT와 SPT와의 상관관계에 대한 연구)

  • Koo, Ja-Kap;Yi, Chang-Tok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.3
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    • pp.231-239
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    • 2003
  • Many foundation jobs have been designed and constructed in Korea with the sole information obtained from the SPT. The use of the CPT to estimate equivalent SPT values is becoming a common application for foundation design. The relationship between the CPT and the SPT has been determined in a number of studies over the past three decades. However a few papers have been published on the relationship between the CPT and the SPT in residual soil. Due to the large variation in published correlations between qt and N in residual soil, local correlations should be developed wherever possible. CPT tests have been carried out in the residual soil classified by SM in accordance with USCM and compared with SPT. Value of qt/N = 0.3 have been suggested for residual soil in Korea.

Effects of camptothecin on the expression of DNA topoisomerase I and c-myc in HL-60 human leukemia cells (HL-60 사람 백혈병 세포에서 camptothecin이 DNA topoisomerase l과 c-myc의 발현에 미치는 영향)

  • 정인철;정대성;류경자;박장수;조무연
    • Journal of Life Science
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    • v.10 no.6
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    • pp.621-629
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    • 2000
  • Camptothecin (CPT) is an antitumor alkaloid that has been isolated from the Chinese tree, Camptotheca acuminata. The cytotoxicity of CPT has been correlated to its inhibition of DNA topoisomerase (Topo) I by stabilizing drug-enzyme-DNA “cleavable complex" resulting in DNA single-strand breaks and DNA-protein crosslinks. This studies were designed to elucidate whether CPT regulates Topo I mediated by CPT in DNAs containing c-myc protooncogene. We have conducted experiments on Topo I purification, pUC-MYC I cloning and Topo I assay using electrophoresis, quantitative RT-PCR and Northern blotting techniques. CPT ingibited the relaxation activity of Topo I in pUC19 DNA at various concentrations (1-1000 $\mu$M), while it enhanced the cleavage of Topo I in the pUC-MYC I by forming a cleavable complex at relatively high concentrations (100-1000 $\mu$M). In HL-60 cells treated with CPT, the expression of c-myc gene was decreased over that in the control group with no changes in the expression of Topo I mRNA. Our results suggest that Topo I is the target of CPT cytotoxicity but it does not affect Topo I extression, and the suppression of c-myc mRNA expression by CPT is due to c-myc damage resulted from formation of a cleavable complex with CPT. CPT.

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Applicability of CPT-based Toe Bearing Capacity of PHC Driven Piles (PHC 항타말뚝에 대한 CPT 선단 지지력 산정식의 적용성)

  • Le, Chi Hung;Chung, Sung-Gyo;Kim, Sung-Ryul
    • Journal of the Korean Geotechnical Society
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    • v.25 no.12
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    • pp.107-118
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    • 2009
  • As CPT penetration tends to show a similar behavior to that of pile driving, a number of methods for estimating the toe bearing capacity of piles based on CPT data have been proposed. To evaluate the applicability of the methods in this country, a total of 172 dynamic load tests data on PHC piles and 82 CPT data at a site in the Nakdong River estuary were collected. A specific four-step procedure was adopted for the selection of the reliable data, and statistical techniques were then applied to the analysis of the applicability. The results indicated that among a total of 10 CPT-based methods applied, the best one is the Aoki method (1975), followed by the LCPC (1982), ICP (2005) methods and others.

Applicability of CPT-based Toe Bearing Capacity of Driven PHC Piles (PHC 항타말뚝에 대한 CPT 선단지지력 공식의 적용성 분석)

  • Le, Chi-Hung;Kim, Sung-Ryul;Chung, Sung-Gyo
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.792-798
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    • 2008
  • CPT 시험은 지난 30여년 동안 지반조사 분야에서 널리 이용되어 왔다. CPT 콘의 근입은 항타말뚝의 근입방법과 유사하기 때문에, CPT 콘의 선단저항력을 이용하여 말뚝의 지지력을 산정하려는 연구가 많이 수행되어 왔다. 본 연구의 목적은 기존에 제안된 CPT 선단지지력 공식의 적용성을 분석하는 것이다. 이를 위해 낙동강 하구 대심도 연약지반에서 수행된 항타 PHC 말뚝에 대한 총 172개의 PDA 시험자료와 80개소의 CPT 자료를 수집하였다. PDA시험의 CAPWAP분석에서 얻어진 선단지지력과 각 CPT 지지력 공식에서 산정된 선단지지력을 비교함으로써 각 공식의 적용성을 분석하였다. 분석에 이용된 CPT 지지력 공식은 Aoki 방법, Meyerhof 방법, Penpile 방법, Philpponnat 방법, LCPC 방법, Schmertmann 방법, Zhou 방법, ICP 방법, Eslami & Fellenius 방법, 그리고 UWA-05 방법의 총 10가지이다. 분석결과, Aoki 방법, Phillipponnat 방법, ICP 방법 그리고 LCPC 방법 순으로 그 적용성이 높은 것으로 나타났다.

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Evaluation of Estimation and Variability of Fines Content in Pohang for CPT-based Liquefaction Assessment (CPT 기반 액상화 평가를 위한 포항지역 세립분 함량 예측 및 변동성 평가)

  • Bong, Tae-Ho;Kim, Sung-Ryul;Yoo, Byeong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.35 no.3
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    • pp.37-46
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    • 2019
  • Recently, the use of CPT-based liquefaction assessment method has increased by providing more accurate results than other field tests. In CPT-based liquefaction evaluation, various soil properties are predicted and they are used for liquefaction potential assessment. In particular, fines content is one of the important input parameters in CPT-based liquefaction assessment, so it is very important to use correct prediction model and to make quantitative evaluation of estimating variability of fines content. In this study, the error evaluation of existing models for prediction of fines content through CPT was performed, and the most suitable model was selected for Pohang area, where the liquefaction phenomenon was observed in the 2017. In addition, the inherent variability of soil was analyzed, and the estimating variability of fines content was evaluated quantitatively considering the inherent variability of soil, measurement error of CPT and transformation uncertainty of selected model.

A Study on the Color Modelling Method for Color Picture Tube Color Display (CPT 색제시를 위한 색모델링 방법 연구)

  • 이응주
    • Journal of Korea Multimedia Society
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    • v.3 no.6
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    • pp.586-591
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    • 2000
  • Color pictures on CPT are generally affected by the receiver characteristic and the condition of exterior illuminants. Moreover, readjustment of incorrect color in the CPT causes color distortion on a given picture. This paper describes a color adjustment method for modelling of CPT at the view point of observer in the ordinary lighting condition. To develop this method, we proposed ways of luminance recompensation under the gamma transformation for the intensity of illuminant, hue/saturation compensation for the types of illuminant and control of specific color for the reference. Based on these method, a color correlation system is suggested with the goal of reducing the color errors which are represented due to the influence of reflectance component of illuminants, the gamma transformation of CPT and the frequently adjustment of reference scene to set a optimum color.

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RELATIONSHIP BETWEEN CHANGES IN EVENT-RELATED POTENTIALS AND CHANGES IN CONTINUOUS PERFORMANCE TEST UNDER THE INFLUENCE OF METHYLPHENIDATE IN ATTENTION-DEFICIT/HYPERACTIVITY DISORDER (주의력 결핍 ${\cdot}$ 과잉행동장애 아동에서 Methylphenidate에 의한 사건관련전위와 연속과제수행 변화사이의 상관성)

  • Choi, Young;Lee, Mu-Suk;Lee, Mi-Suk
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.8 no.2
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    • pp.273-286
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    • 1997
  • Objective:This study was designed to evaluate effects of methylphenidate(MPH) on event-related potentials(ERP) and continuous performance test(CPT) in attention-deficit hyperactivity disorder (ADHD) and to see the correlation between changes in ERP and changes in performance. Method:ERP and CPT were used to examine the acute effects of MPH(0.5mg/kg) in eleven ADHD boys(89-103 months old). Results:1) After MPH administration, P3 latency to nontarget stimuli at Fz was significantly decreased (p<0.01) and P2 amplitudes to target stimuli at Pz and at Oz and P3 amplitude to target stimuli at Cz were significantly increased(p<0.05). 2) Commission error and omission error in the CPT-X and commission error in the CPT-AX were decreased(p<0.01), and hits and perceptual sensitivity(d') in the CPT-X and d′ in the CPT-AX were increased(p<0.01). 3) The change of P3 latency to nontarget stimuli at Fz and the change of d′ in the CPT-X were negatively correlated(p<0.05), and the change of P2 amplitude to target stimuli at Pz and d′ in the CPT-AX were positively correlated(p<0.05). Conclusion:MPH improves change orienting reaction, the delivery of task relevant information, accuracy and perceptual sensitivity in ADHD. And the increase of ability to discriminate targets from non-targets reflects reduced evaluation time in large memory component task and enhanced change orienting reaction in simple task.

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Effects of Exercise and/or High Fat Diet on Carnitine and Carnitine Palmitoyltransfersase-I mRNA Levels in Rats (운동 및 고지방식이가 흰쥐의 Carnitine 농도와 carnitine Palmitoyltransferase-I mRNA 수준에 미치는 영향)

  • 손희숙;오석흥;차연수
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.3
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    • pp.670-676
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    • 1999
  • The effect of exercise and/or high fat diet on carnitine status and carnitine palmitoyltransferase I(CPT I) level were investigated in Weanling Sprague Dawley rats. The rats were fed an AIN 76 diet or a modified high fat AIN diet, supplemented with 35% corn oil, for 31 days. During the 31 day period half of the animals in each dietary group were exercised on a treadmill for 90 minutes per day. Carnitine concentrations were determined in plasma and liver and CPT I mRNA levels were measured by Northern blot analysis with CPT I cDNA probe in livers of rats. Exercise rats gained less weight than non exercised rats during the study for high fat diet group. Exercise rats had a higher plasma acid soluble acylcarnitine and acid insoluble acylcarnitine concnetrations than non exercised rats for normal diet group. Exercise or high fat diet increased liver carnitine concentration, but a mixed effect was not shown. In exercised rats, CPT I mRNA levels increased significantly relative to those of nonexercised rats. CPT I mRNA levels also increased when compared high fat fed rats with those of normal diet fed rats. These data suggest that there is a correlation between carnitine concen trations and CPT I mRNA levels and that CPT I can be regulated at the transcriptional level by exercise and/or high fat diet.

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A NEW CPT-BASED METHOD FOR UNDRAINED SHEAR STRENGTH ESTIMATION OF CLAYS

  • Lee, Jun-Hwan
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.18-23
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    • 2010
  • The estimation of the undrained shear strength $s_u$ for clays using CPT results has been mainly based on the cone factor $N_k$. In this study, a new CPT-based method for the estimation of the undrained shear strength $s_u$ is presented. This aims at reducing uncertainties for the estimation of $s_u$ and enhancing the application of CPT results in more effective manner. For this purpose, a site located at a marine clay deposit is selected and test results from extensive experimental testing program are adopted. The new method defines a direct correlation between the undrained shear strength $s_u$ and the cone resistance $q_t$, excluding the procedure of the overburden pressure correction and therefore undisturbed soil sampling process. In order to verify the new CPT-based method, additional test sites and example sites from literature, which consist of a variety of soil conditions, are selected and examined. It is observed that values of su obtained from the proposed method are in good agreements with measured values of $s_u$ for all the selected verification cases.

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