• The Korean Journal of Physiology and Pharmacology
• /
• v.17 no.4
• /
• pp.291-297
• /
• 2013

Notch1 has been reported to be highly expressed in triple-negative and other subtypes of breast cancer. Mutant p53 (R280K) is overexpressed in MDA-MB-231 triple-negative human breast cancer cells. The present study aimed to determine whether the mutant p53 can be a potent transcriptional activator of the Notch1 in MDA-MB-231 cells, and explore the role of this mutant p53-Notch1 axis in curcumin-induced apoptosis. We found that curcumin treatment resulted in an induction of apoptosis in MDA-MB-231 cells, together with downregulation of Notch1 and its downstream target, Hes1. This reduction in Notch1 expression was determined to be due to the decreased activity of endogenous mutant p53. We confirmed the suppressive effect of curcumin on Notch1 transcription by performing a Notch1 promoter-driven reporter assay and identified a putative p53-binding site in the Notch1 promoter by EMSA and chromatin immunoprecipitation analysis. Overexpression of mutant p53 increased Notch1 promoter activity, whereas knockdown of mutant p53 by small interfering RNA suppressed Notch1 expression, leading to the induction of cellular apoptosis. Moreover, curcumin-induced apoptosis was further enhanced by the knockdown of Notch1 or mutant p53, but it was decreased by the overexpression of active Notch1. Taken together, our results demonstrate, for the first time, that Notch1 is a transcriptional target of mutant p53 in breast cancer cells and suggest that the targeting of mutant p53 and/or Notch1 may be combined with a chemotherapeutic strategy to improve the response of breast cancer cells to curcumin.

• The Korean Journal of Zoology
• /
• v.32 no.3
• /
• pp.242-251
• /
• 1989

Morphometric and genetic analyses on six populations of the two subspecies of Cobitis koreensis were performed to investigate the geographic variation and to clarify their taxonomic status. No significant differences between subspecies were found. Puan population of C. k. pumilus tends to be smaller in numbers of cross bars and dorsal spots, than those of C. k. koreensis populations with no statistical significance. Average degree of genic variation among six populations of the two subspecies was A=1.5, P =37.3%, HD=0.053, and HG=0.097. Marginal populations of Samchog (C. k. koreensis) and Puan(C. k. pumilus) were least variable: A= 1.3, P=23.8%, HD=0.0l0, HG=0.043, and A= 1.2, P=19.0%, HD=0.029, HG=0.078 respectively.The difference between HD and HG in all populations may indicate a patchness distribution between demes within each population. Genetic similarities between the two subspecies were, on the average, S=0.894, and this value correspond to the average genetic similarities among five populations of C. k. koreensis (5=0.899). Chongup population of C. k. koreensis and Puan population of C. k. pumilus was most similar genetically (5 =0.931). The results of morphometric and genetic analysis in this study indicate that C. k. pumilus is not a valid subspecies and should be considered as a population of C. koreensis.

• The Journal of Society for e-Business Studies
• /
• v.14 no.2
• /
• pp.71-94
• /
• 2009

The purpose of this study is to identify the effects of interactivity, computer playfulness, and computer anxiety on service satisfaction, attitude, and user intention based on the flow theory in order to understand factors improving effects of home-network system. Especially, Computer anxiety which is one of individual characteristics in negative aspect as well as computer playfulness was added to the research model to perform empirical research for grasping effects on attitude variables such as service satisfaction. The analysis resulted that the perceived interactivity and the computer playfulness had a positive relationship with service satisfaction, but on the contrary it was identified that the computer anxiety gave a negative effect on the service satisfaction. These results are evidences to explain high correlation of the perceived interactivity, the computer playfulness, and the computer anxiety with the service satisfaction. Besides, it was found that there was a meaningful relationship among the three attitude variables such as satisfaction, attitude, and intention to use. This research suggested an integrative research model using home-network technology where user satisfaction and use factors were included, expanded research area of the traditional interactivity, and presented a consistent result to support the relationship among the service satisfaction, the attitude, and the intention to use. In additions, practical issues were also provided by presenting user's criteria for selecting various services including electronic commerce and its using elements continuously.

• Journal of the Korean Electrochemical Society
• /
• v.15 no.4
• /
• pp.216-221
• /
• 2012

Electrochemical reduction of carbon dioxide has been widely studied by many scientists and researchers. Recently, the production of formic acid, which is expensive but highly useful liquid material, is receiving a great attention. However, difficulties in the electrochemical reduction process and analyzing methods impede the researches. Therefore, it is important to design an adequate system, develop the reduction process and establish the analyzing methods for carbon dioxide reduction to formic acid. In this study, the production of formic acid through electrochemical reduction of carbon dioxide was performed and concentration of the product has been analyzed. Large scale batch cell with proton exchange membrane was used in the experiment. The electrochemical experiment has been performed using a series of metal catalysts. Linear sweep voltammetry (LSV) and chronoamperometry were performed for carbon dioxide reduction and electrochemical analysis using silver chloride and platinum electrode as a reference electrode and counter electrode, respectively. The concentration of formic acid generated from the reduction was monitored using high performance liquid chromatography (HPLC). The results validate the appropriateness and effectiveness of the designed system and analyzing tool.

• The Journal of Korean Medicine
• /
• v.38 no.2
• /
• pp.61-72
• /
• 2017

Objectives: The effects of Gamiondam-tang (GMODT) co-administration within 5min on the pharmacokinetics (PK) of tamoxifen were observed as a process of the comprehensive and integrative medicine, combination therapy of tamoxifen with GMODT to achieve synergic pharmacodynamics and reduce toxicity on the breast cancer. Methods: After 50mg/kg of tamoxifen treatment, GMODT 100mg/kg was administered within 5min. The plasma were collected at 30 min before administration, 30 min, 1, 2, 3, 4, 6, 8 and 24 hrs after end of GMODT treatment, and plasma concentrations of tamoxifen were analyzed using LC-MS/MS methods. PK parameters of tamoxifen (Tmax, Cmax, AUC, $t_{1/2}$ and $MRT_{inf}$) were analysis as compared with tamoxifen single administered rats using noncompartmental pharmacokinetics data analyzer programs. Results: Co-administration with GMODT induced increased trends of plasma tamoxifen concentrations to 1hr after end of administration, and then showed decreased trends of plasma tamoxifen concentrations, and especially significant (p<0.05) increases of plasma tamoxifen concentrations were demonstrated at 0.5hr after end of co-administration with GMODT and also related significant (p<0.05) decreases of $AUC_{0-inf}$ and $MRT_{inf}$ as compared with tamoxifen single formula treated rats, at dosage levels of tamoxifen 10 mg/kg and GMODT 100 mg/kg within 5 min, in this experiment. Conclusion: Based on the results of the present study, it is considered that single co-administration GMODT within 5min significantly inhibited the oral bioavailability of tamoxifen through variable influences on the absorption and excretion of tamoxifen, can be influenced on the toxicity or pharmacodynamic of tamoxifen.

• The Journal of the Korea Contents Association
• /
• v.8 no.11
• /
• pp.412-425
• /
• 2008

One of the important elements for improving academic achievement of learners in education through e-learning is to support learners to study by finding questions they want with providing various evaluation questions. However, most of question retrieval systems usually depend on keyword search based on only a syntactical analysis and/or a hierarchical browsing system classified by the topics of subjects. In such a system it is not easy to find integrative questions associated with each other. In order to improve this problem, in this paper we proposed a question management and retrieval system which allows users to easily manage questions and also to effectively find questions for study on the Web. Then, we implemented a system that gives to access questions for the domain of C language programming. The system makes it possible to easily search questions related to not only a single theme but also questions integrated by interrelationship between topics and questions. This is done by supporting to be able to retrieve questions according to conceptual interrelationships between questions from user query. Consequently, it is expected that the proposed system will provide learners to understand the basic theories and the concepts of the subjects as well as to improve the ability of comprehensive knowledge utilization and problem-solving.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.9
• /
• pp.1437-1444
• /
• 2007

A response surface model was developed for predicting the growth rates of Staphylococcus aureus in tryptic soy broth (TSB) medium as a function of combined effects of temperature, pH, and NaCl. The TSB containing six different concentrations of NaCl (0, 2, 4, 6, 8, and 10%) was adjusted to an initial of six different pH levels (pH 4, 5, 6, 7, 8, 9, and 10) and incubated at 10, 20, 30, and $40^{\circ}C$. In all experimental variables, the primary growth curves were well ($r^2=0.9000$ to 0.9975) fitted to a Gompertz equation to obtain growth rates. The secondary response surface model for natural logarithm transformations of growth rates as a function of combined effects of temperature, pH, and NaCl was obtained by SAS's general linear analysis. The predicted growth rates of the S. aureus were generally decreased by basic (pH 9-10) or acidic (pH 5-6) conditions and higher NaCl concentrations. The response surface model was identified as an appropriate secondary model for growth rates on the basis of correlation coefficient (r=0.9703), determination coefficient ($r^2=0.9415$), mean square error (MSE=0.0185), bias factor ($B_f=1.0216$), and accuracy factor ($A_f=1.2583$). Therefore, the developed secondary model proved reliable for predictions of the combined effect of temperature, NaCl, and pH on growth rates for S. aureus in TSB medium.

• Journal of Korea Technology Innovation Society
• /
• v.16 no.2
• /
• pp.506-529
• /
• 2013

Nagoya protocol, alias ABS adopted in UN Convention on Biodiversity in 2010, has prompted governments in many countries to prepare strategic plans with regards to both the conservation of domestic bio-resources and the use of those with foreign origin. This study aims to evaluate the effectiveness of policy responses of Korean governments to ABS (Access and Benefit Sharing) and to make suggestions for a more integrative and efficient governance system for related ministries and institutions. Our analysis indicates that while most ministries have designated laws specifying various measures for the conservation of domestic bio-resources such as protected biological species or natural areas, just a couple of them have instituted measures governing the use of those resources and the benefit-sharing arising from it. We conclude that policy responses of Korean government are more focused on the conservation of bio-resources leaving the use of them ill-addressed. The study, thus, suggests that measures of 'bio-resource user country' be instituted in addition to those of 'bio-resource supplier country'. For instance, with regards to the use of bio-resources the roles and remits of related ministries had better be clarified and coordinated. The uncertainty over the explicit indication of 'place of origin' of bio-resources as a requirement of patent grant need to be cleared as well.

• Information Systems Review
• /
• v.18 no.2
• /
• pp.151-171
• /
• 2016

With the widespread adoption of mobile devices, such as smart phones and smart pads, as well as the rapid growth of mobile technologies, consumer shopping patterns are changing. This study investigates key factors of consumer purchasing intention in a mobile shopping mall context by incorporating trust belief into the theory of planned behavior. We posit perceived usefulness, perceived enjoyment, perceived ease of use, and trust belief as antecedents of behavioral attitude toward mobile shopping malls. Moreover, social influence and security are identified as key enablers of trust belief on mobile shopping malls. Data collected from 154 consumers with purchasing experience in mobile shopping malls are empirically tested against a research model using partial least squares. Analysis results show that behavioral attitude and perceived behavioral control significantly influence purchasing intention. Moreover, this study reveals the significant effects of perceived usefulness and perceived enjoyment on behavioral attitude. Trust belief indirectly influences purchasing intention through behavioral attitude and is significantly affected by social influence. Understanding consumer purchasing decision-making processes in mobile shopping malls can help service providers to develop effective marketing and operation strategies and campaigns.

• Journal of Society of Preventive Korean Medicine
• /
• v.21 no.2
• /
• pp.127-137
• /
• 2017

Objectives : In our previous study, single co-administration GMODT within 5 min significantly inhibited the oral bioavailability of tamoxifen through variable influences on the absorption and excretion of tamoxifen. Therefore, the object of this study was to elucidate the possible effects on the pharmacokinetics of tamoxifen after single oral co-administration of GMODT with 2.5 hr-intervals. Methods : After 50 mg/kg of tamoxifen treatment, GMODT 100 mg/kg was administered with 2.5 hr-intervals. The plasma were collected at 30 min before administration, 30 min, 1, 2, 3, 4, 6, 8 and 24 hrs after end of GMODT treatment, and plasma concentrations of tamoxifen were analyzed using LC-MS/MS methods. PK parameters of tamoxifen (Tmax, Cmax, AUC, $t_{1/2}$ and $MRT_{inf}$) were analysis as compared with tamoxifen single administered rats. Results : Two-half hr-interval co-administration with GMODT induced variable changes on the plasma tamoxifen concentrations as compared with tamoxifen single treated rats, and especially significant (p<0.05) increases of plasma tamoxifen concentrations were demonstrated at 0.5 (199.61%) and 1 hr (101.06%) after end of co-administration with GMODT, and also related significant (p<0.05) decreases of $t_{1/2}$ (-39.54%) and $MRT_{inf}$ (-43.94%) as compared with tamoxifen single formula treated rats, at dosage levels of tamoxifen 50 mg/kg and GMODT 100 mg/kg with 2.5 hr-intervals, in this experiment. Conclusions : According to the results, GMODT critically decreased on the oral bioavailability of tamoxifen through variable influences on the absorption and excretion of tamoxifen. Hence, the co-administration of GMODT and tamoxifen should be avoided in the comprehensive and integrative medicine, combination therapy of tamoxifen with GMODT on the breast cancer.