• Animal cells and systems
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• 제15권1호
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• pp.9-17
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• 2011

Colorectal cancer is the third leading cause of cancer-related death in Western countries. Chemotherapeutic agents with different mechanisms of action have shown an increase in cure rates. In the present study, we investigated the effect of a combination of low concentration of paclitaxel (taxol, 5 nM) and topoisomerase 1 inhibitor camptothecin (CPT) on HCT116 colon cancer cells. Although the viability of cells treated with taxol alone was similar to that of control cells, sequential treatment with taxol and CPT exhibited high cytotoxicity. However, the opposite sequence of treatment did not exert cytotoxic effects on HCT116 cells. This enhanced cytotoxicity of the sequential combination therapy was the result of mitotic arrest, which increased the level of $p21^{Cip1/WAF1}$ through the p38 mitogen-activated protein kinase (MAPK) pathway. Knockdown by $p21^{Cip1/WAF1}$ siRNA or treatment with a p38 inhibitor reduced the viability of cells sequentially exposed to taxol and CPT. Taken together, a low taxol concentration in combination with CPT induced mitotic arrest in HCT116 cells, leading to synergistic cell death through enhanced expression of $p21^{Cip1/WAF1}$ and p38 MAPK pathway. Therefore, taxol could playa role as a sensitizer of CPT in colon cancer cells.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1083-1086
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• 2008

In this study, Estimate solutions of ultimate lateral resistances for lateral loaded piles are proposed using cone penetration values, $q_c$ values, as CPT results. Cone penetration values, $q_c$ values measured on clean sand layers, are represented by factors for relative densities, axial stresses, and lateral stresses which are important on analysis of sandy soil layers. Also, these factors are same factors to consider existed estimations of ultimate lateral capacity. In this study, estimation of ultimate lateral capacity for lateral loaded piles using CPT results is proposed, and this estimation is verified by adequate analysis for effective reliability.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권1호
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• pp.32-36
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• 2003

Production of camptothecin ((PT) from callus cultures of Camptotheca acuminata Decne was affected by light and culture conditions. Among the culture media tested, modified B5 medium containing 3% (w/v) sucrose, 2 mg/L B,4-D, 2 times of MS medium vitamins, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.05% (w/v) activated charcoal, and 0.15% (w/v) gelite was used for callus induction . The highest cell growth and CPT production were obtained in dark and green light condition, respectively. Photoperiod has no effect on cell growth and CPT production. Both cell growth and CPT production were also influenced by combination ratio of red and blue light .Cell growth and CPT production were the highest in the ratio of red and blue light,90:10.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.320-325
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• 2009

The constrained modulus, representative property to evaluate compressibility of soil, is needed to estimate the settlement of ground structure. A series of lab and field cone penetration tests for clayey soil of Busan new-port and Noksan industrial area were conducted to evaluate the estimation method of constrained modulus. Since CPT generates large deformation of ground, it is difficult to correlate the cone resistance with the constrained modulus. Therefore, appropriate correlation between them is essential to estimate the constrained modulus based on CPT results. The test results show that the ratio of the constrained modulus to the cone resistance is inversely proportional with plasticity index. Based on this result, the estimation method of constrained modulus for Busan clay is suggested.

• 한국표면공학회지
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• 제39권1호
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• pp.18-24
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• 2006

Although stainless steels have the excellent corrosion resistance by passive film, they are susceptible to pitting corrosion in the environment containing halogen elements such as chloride ions. The resistance to pitting corrosion can be evaluated by measuring the critical pitting temperature (CPT). CPT values can be obtained using immersion, potentiodynamic and potentiostatic polarization test methods. Results on duplex 2205 stainless steels showed that CPT values were measured as $50^{\circ}C,\;55^{\circ}C\;and\;61^{\circ}C$, respectively for immersion, potentiodynamic and potentiostatic polarization test methods, depending upon the different test methods, even though the difference between CPT values are not much.

• 운동영양학회지
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• 제16권1호
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• pp.1-9
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• 2012

Long chain fatty acids (LCFAs) are transported into cells via plasma transporters, are activated to fatty acyl-CoA by fatty acyl-CoA synthase (ACS), and enter mitochondria via the carnitine system (CPT1/CACT/CPT2). The mitochondrial carnitine system plays an obligatory role in β-oxidation of LCFAs by catalyzing their transport into the mitochondrial matrix. Fatty acyl-CoAs are oxidized via the β-oxidation pathway, which results in the production of acetyl-CoA. The acetyl-CoA can be imported into the tricarboxylic acid (TCA) cycle for oxidation in the mitochondrial matrix or can be used for malonyl-CoA synthesis by acetyl-CoA carboxylase 2 (ACC2) in the cytoplasm. In skeletal muscle, ACC2 catalyzes the carboxylation of acetyl-CoA to form malonyl-CoA, which is a potent endogenous inhibitor of carnitine palmitoyltransferase 1 (CPT1). Thus, ACC2 indirectly inhibits the influx of fatty acids into the mitochondria. Fatty acid metabolism can also be regulated by malonyl-CoA-mediated inhibition of CPT1.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.269-281
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• 2010

The cone penetration test(CPT) has been increasingly used for in situ site characterization. However, the use of CPT is often limited due to specific site conditions depending on the cone size, geometry, and capacity of the CPT system used. In South Korea, it has generally been considered that the CPT could be satisfactorily performed only in soft soils. Louisiana State University/ Louisiana Transportation Research Center has implemented a field-rugged continuous intrusion miniature cone penetration test (CIMCPT) system since the 1990s. The miniature cone penetrometer of the CIMCPT system has a cross-sectional cone area of $2cm^2$ allowing finer soil profiles compared to the standard $10cm^2$. The reduced cross-sectional area also enables a system capacity reduction leading to cost saving and ease in maintenance. In addition, the continuous intrusion mechanism allows fast and economic site investigations. Samsung C&T Corporation has recently implemented a similar CIMCPT system. In this study, case studies on the field application of Samsung CIMCPT system for the last 2 years are presented to illustrate its performance investigation and its usefulness and limitation. Results of the case studies show that the CIMCPT system can be applied to soils with cone tip resistance($q_c$) values up to about 30MPa and allows a reliable and useful way to characterize soft soils. The results also show that the rod buckling limits the investigation depth by the system and the large contact pressure of the CIMCPT truck prevents the use of the system at sites with soft surface soils. According to the results of the case studies, the Samsung CIMCPT system has been being upgraded with a miniature cone with a longer rod, a crawler-type transportation system, a pre-boring system, and so on.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1253-1257
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• 2011

The surface structures, adsorption conditions, and thermal desorption behaviors of cyclopentanethiol (CPT) self-assembled monolayers (SAMs) on Au(111) were investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and thermal desorption spectroscopy (TDS). STM imaging revealed that although the adsorption of CPT on Au(111) at room temperature generates disordered SAMs, CPT molecules at $50^{\circ}C$ formed well-ordered SAMs with a $(2{\surd}3{\times}{\surd}5)R41^{\circ}$ packing structure. XPS measurements showed that CPT SAMs at room temperature were formed via chemical reactions between the sulfur atoms and gold surfaces. TDS measurements showed two dominant TD peaks for the decomposed fragments ($C_5H_9^+$, m/e = 69) generated via C-S bond cleavage and the parent molecular species ($C_5H_9SH^+$, m/e = 102) derived from a recombination of the chemisorbed thiolates and hydrogen atoms near 440 K. Interestingly, dimerization of sulfur atoms in n-alkanethiol SAMs usually occurs during thermal desorption and the same reaction did not happen for CPT SAMs, which may be due to the steric hindrance of cyclic rings of the CPT molecules. In this study, we demonstrated that the alicyclic ring of organic thiols strongly affected the surface structure and thermal desorption behavior of SAMs, thus providing a good method for controlling chemical and physical properties of organic thiol SAMs.

• The Korean Journal of Pain
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• 제10권1호
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• pp.5-10
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• 1997

Background : The Current Perception Threshold (CPT) provides an objective, quantitative gauge of sensory nerve integrity which is obtainable from any cutaneous site. CPT measurement can confirm and quantify or rule out dysfunction of nerve through comparison with established normative values ($Neuval^{TM}$ CPT database). The aim of this study is to compare collected data from Korean adults with $Neuval^{TM}$ CPT database. Method : Normative data from 5 standard test site in face, hand, toe were obtained from 50 healthy adults. Three frequencies(5, 250, 2000 Hz) were stimulated with $Neuromoter^{(R)}$ CPT device. Results : The results of our data were statistically significantly different than Neuval data except in face, but within normal range. Sensory Threshold increased as the frequency of the stimulus changed from 5 Hz to 250 Hz to 2000 Hz., and from face to hand to toe. Conclusion : CPT testing is a valuable neurologic testing modality that is noninvasive and highly reliable for diagnosis and evaluation of sensory nerves where neuropathy is suspected.

• The Korean Journal of Pain
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• 제13권1호
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• pp.97-100
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• 2000

Thoracic outlet syndrome (TOS) is a combination of signs and symptoms caused by the compression of the vital neurovascular structure at the thoracic outlet region. It may stem from a number of abnormalities, including degenerative or bony disorders, trauma to cervical spine, fibromuscular bands, vascular abnormalities and spasm of the anterior scalene muscle. CPT (current perception threshold) is defined as the minimum amount of current applied transcutaneously that an individual consciously perceives. It enables quantification of the hyperesthesia that precedes progressive nerve impairment, as well as hypoesthetic conditions. We experienced a case of thoracic outlet syndrome caused by fibrosis of anterior scalene muscle. The patient was a 30 years old woman with a 3 years history of numbness on the ulnar side, progressive weakness and coldness of both hand, tiredness in the left arm, nocturnal pain in the left forearm, and pain in the left elbow, shoulder and neck. Conservative treatment, stellate ganglion block, cervical epidural block, anterior scalene block and previous operation, including both carpal tunnel release, provided no remarkable relief to the patient. A left scalenectomy and first rib resection were performed by transaxillary approach and left cervical root neurolysis was done. After surgery, we measured CPT using neurometer and found conditions worsening in the opposite arm. We performed the same procedure on right side, and followed by CPT measurement. This case suggests that CPT is a useful measurement of recovery and progression of TOS.