• Toxicological Research
• /
• v.13 no.3
• /
• pp.257-263
• /
• 1997

Pentachlorophenol(PCP) which ks widely used in wood preservation, pulp and paper mills, has led to a substantial envirortmental contamination. To get the reliable data for the effective health risk assessment with PCP, covalent binding potential of PCP to cellular macromolecules and glutathione(GSH) was investigated after intraperitoneal administration of $^{14}C-PCP$ to rats. PCP metabolites were able to bind covalently to serum albumin and hepatic protein in a dose- and time-dependent manner. Hepatic protein adducts of PCP metabolites were increased as a function of cytochrome P-450 activities, whereas, albumin adducts significantly decreased. Covalent binding of PCP metabolites with DNA or hemoglobin was not observed. GSH levels in liver tissue decreased over 12hrs, however, the level was recovered after 48hrs. Tetrachloro-1,4-benzoquinone (1,4-TCBQ), one of the most reactive PCP metabolites, conjugated with GSH very rapidly. Base on our results, we could conclude that PCP metabolized to reactive electrophilic metabolites by cytochrome P-450 isoenzymes and conjugated rapidly with neighboring protein or nonprotein sulfhydryl before reacting with DNA or hemoglobin. We propose that albumin adducts and mercapturic acids of PCP metabolites can be used good biomarker of recent PCP exposure.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.37 no.9
• /
• pp.30-37
• /
• 2000

In this paper, design and fabrication of miniature voltage-controlled oscillator(VCO) is discussed . Based on the two-port circuit analysis technique, VCO for 900MHz cellular mobile phone is designed and circuit parameters are optimized using the circuit simulator. Using the optimized design parameters, miniature VCO with 6${\times}$6${\times}$1.8 mm$^3$(0.065cc) dimensions is fabricated and experimented. Experimental results show that implemented VCO has -3.5 dBm output power level and 45MHz tunung range, respectively, and has -101.5dB/Hz Phase noise performance at 10 KHz frequency offset.

• Journal of Korean Institute of Industrial Engineers
• /
• v.36 no.1
• /
• pp.52-58
• /
• 2010

The level of competition has reached the limits in cellular phone market and the cellular phone manufacture companies started to focus their solution in user interface. Design issues with controllability led the development and renovation of such products to the use of the touch-screen phone. Depending upon the readability, technical advances, portability and controllability, user satisfaction of touch-screen phones could vary significantly. In this research, the controllability was dealt in regard to various grip postures, in order to improve menu layout which fits for using the thumbs of both hands and a thumbs of single hand. Regression models are found to the suggest the location of buttons on the screen by redesigning the menu layout, it is expected to improve both controllability and satisfaction of the user. This result can be applicable not only to mobile phone design, but also to the design of various hand-held devices using a touch screen.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.5
• /
• pp.1929-1933
• /
• 2012

Oxidative stress has been proposed to be involved in colorectal cancer development. Many dark pigments of plants have potent oxidative stress preventive properties. In this study, unpolished Thai rice was assessed for antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. Red strain unpolished Thai rice was also administered to rats exposed to azoxymethane (AOM) for induction of aberrant crypt foci (ACF). Serum malondialdehyde (MDA) and ferric reducing antioxidant power (FRAP) were investigated for cellular oxidative stress and serum antioxidants, respectively. Red pigment unpolished Thai rice demonstrated high antioxidant activity and was found to significantly and dose dependently decrease the total density and crypt multiplicity of ACF. Consumption of Thai rice further resulted in high serum antioxidant activity and low MDA cellular oxidative stress. Interestingly, the density of ACF was strongly related to MDA at r = 0.964, while it was inversely related with FRAP antioxidants (r = -0.915, p < 0.001). The results of this study suggest that the consumption of red strain of unpolished Thai rice may exert potentially beneficial effects on colorectal cancer through decrease in the level of oxidative stress.

• Journal of Nutrition and Health
• /
• v.32 no.4
• /
• pp.394-400
• /
• 1999

Since it has generally been considered that high-hat diets promote carcinogenesis, fat intake of less than 30% of total calories has been recommended to reduce the risk of cancer. Specific dietary guidelines for fat intake to reduce the risk of colon cancer have not yet been established. In order to determine the level of dietary fat needed the risk of colon cancer, rats were fed one of four experimental fat diets, very low(7% of total calories from corn oil, VLC), low(15% LC), medium (30%, MC), and high fat(45%, HC). Cell proliferation as an intermediate biomarker of color carcinogenesis was measured by the in vivo incorporation of bromodeoxyuridine into DNA. Fecal lipid excretion was measured by gravimetric method. As fat levels in the diet increased, fecal lipid concentrations also increased (VLC

• BMB Reports
• /
• v.43 no.3
• /
• pp.199-204
• /
• 2010

The protein p104 was first isolated as a binding partner of the Src homology domain of phospholipase C$\gamma$1, and has been shown to associate with p85$\alpha$, Grb2. The ectopic expression of p104 reduced cellular growth rate, which was also achieved with the overexpression of only the proline-rich region of p104. The proline-rich region of p104 has been found to inhibit the colony formation of platelet-derived growth factor BB-stimulated NIH3T3 cells and MCF7 cancer cells on soft agar. Mutagenesis analysis showed that the second and third proline-rich regions are essential for growth control, as well as for interaction with p85$\alpha$. Overexpression of p104 increased the level of the cyclin-dependent kinase inhibitor, $p27^{Kip1}$, and inhibited the activity of phosphoinositide 3-kinase (PI3K). In summary, p104 interacts with p85$\alpha$ and is involved in the regulation of $p27^{Kip1}$ expression for the reduction of cellular proliferation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.4A
• /
• pp.316-323
• /
• 2009

Power allocation of soft frequency reuse(SFR) to increase cell edge user throughput by reducing inter-cell interference is proposed for coordinated cellular systems. SFR is the effective technique to increase cell edge user throughput, however, it costs the degradation of total system throughput. The cost increases when SFR operated in distributed resource controlled systems fails to be fast adaptive in the change of user distribution. The proposed scheme enables coordinated cells to control transmit power adaptively depending on user distribution so that it minimizes the loss of system throughput introduced from SFR while it guarantees enhancement of cell edge user throughput. Through system level simulation considering neighboring two cells, evaluation result for adaptive power allocation is shown compared with static power allocation.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.11
• /
• pp.2028-2036
• /
• 2017

The Escherichia coli K-12 and B strains are among the most frequently used bacterial hosts for scientific research and biotechnological applications. However, omics analyses have revealed that E. coli K-12 and B exhibit notably different genotypic and phenotypic attributes, even though they were derived from the same ancestor. In a previous study, we identified a limited number of proteins from the two strains using two-dimensional gel electrophoresis and tandem mass spectrometry (MS/MS). In this study, an in-depth analysis of the physiological behavior of the E. coli K-12 and B strains at the proteomic level was performed using six-plex isobaric tandem mass tag-based quantitative MS. Additionally, the best lysis buffer for increasing the efficiency of protein extraction was selected from three tested buffers prior to the quantitative proteomic analysis. This study identifies the largest number of proteins in the two E. coli strains reported to date and is the first to show the dynamics of these proteins. Notable differences in proteins associated with key cellular properties, including some metabolic pathways, the biosynthesis and degradation of amino acids, membrane integrity, cellular tolerance, and motility, were found between the two representative strains. Compared with previous studies, these proteomic results provide a more holistic view of the overall state of E. coli cells based on a single proteomic study and reveal significant insights into why the two strains show distinct phenotypes. Additionally, the resulting data provide in-depth information that will help fine-tune processes in the future.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.8 no.4
• /
• pp.273-288
• /
• 2012

In recent years, smartphone is the most widely used ubiquitous functionality. People do not want to just call other people any more by using a cellular phone; they want to connect to the Internet and use various applications. Hence, cellular phones need to become smart. A smartphone has an operating system and many applications. Specifically the goals of this research are; (1) to suggest theory framework of acceptance about smartphone based on TAM, (2) to examine relationships between exogenous variables. The research model and hypotheses were developed based on the theories of technology acceptance model. Questionnaire was used to collect data. The analysis of this study is designed as individual level to examine the causal relationship among variables. The the reliability and validity of data was tested by explanatory factor analysis, Cronbach's alpha coefficient, confirmatory factor analysis, and correlation analysis. Also, the structural equation model(SEM) analysis was performed to test the usefulness of the model. The analysis results revealed that social norms and individual innovation are major influential variables on the perceived usefulness of smartphone. Also, social norms are influential variables on the perceived enjoyment of smartphone.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.4
• /
• pp.1424-1441
• /
• 2014

Two-tier femtocell networks, consisting of a conventional cellular network underlaid with femtocell hotspots, play an important role in the indoor coverage and capacity of cellular networks. However, the cross- and co-tier interference will cause an unacceptable quality of service (QoS) for users with universal frequency reuse. In this paper, we propose a novel downlink interference mitigation strategy for spectrum-shared two-tier femtocell networks. The proposed solution is composed of three parts. The first is femtocells clustering, which maximizes the distance between femtocells using the same slot resource to mitigate co-tier interference. The second is to assign macrocell users (MUEs) to clusters by max-min criterion, by which each MUE can avoid using the same resource as the nearest femtocell. The third is a novel adaptive power control scheme with femtocells downlink transmit power adjusted adaptively based on the signal to interference plus noise ratio (SINR) level of neighboring users. Simulation results show that the proposed scheme can effectively increase the successful transmission ratio and ergodic capacity of femtocells, while guaranteeing QoS of the macrocell.