We provide evidence suggesting that RANKL, which activates osteoclasts, plays a significant role in the mechanism of bone destruction in cholesteatoma, and that the ratio of RANKL to OPG may be a reliable indicator of bone destruction in cholesteatoma.

Squamous cell carcinoma of the head and neck (SCCHN) is a relatively rare cancer with a poor prognosis. In the present study, we investigated susceptibility biomarkers for SCCHN in 155 Koreans (73 SCCHN cases and 82 controls). Expression of the xeroderma pigmentosum group C (XPC) DNA-repair gene was measured by TaqMan fluorogenic real-time RT-PCR using RNA isolated from peripheral blood samples. In addition, the XPC-PAT genotype [an intronic and biallelic poly(AT) insertion/deletion polymorphism] was determined by PCR of peripheral blood DNA. Among known environmental and physical risk factors, age, gender, tobacco smoking, and alcohol consumption were associated with the SCCHN risk (P < 0.01). Lower XPC expression levels were found for the SCCHN cases, particularly in the larynx, than for the controls (P < 0.05); the geometric means (standard deviations) of XPC expression normalized by 18S rRNA in the cases and controls were 5.89 (8.13) and 15.14 (9.77), respectively. However, the distributions of the XPC-PAT genotypes were similar in the cases and controls. In addition, there were no associations between the expression of XPC and the PAT genetic polymorphism. XPC expression was not affected by age, gender, tobacco smoking, or alcohol consumption. After adjusting for SCCHN-associated lifestyle factors, the effective strength of XPC expression on SCCHN risk was weaker (0.05 < P < 0.1) than those of tobacco smoking and age (P < 0.05). There was a positive association between XPC mRNA expression in blood and SCCHN tissues (n = 9; P < 0.01); therefore, peripheral blood appears to be a reasonable surrogate tissue for XPC expression in tumor tissue. In conclusion, the XPC-PAT polymorphism had no effect on XPC expression or SCCHN risk. However, XPC expression may influence SCCHN risk.

-In this paper, a comparative study on the frequency estimation methods using IRDWT (Improved Recursive Discrete Wavelet Transform), FRDWT(Fast Recursive Discrete Wavelet Transform), and GCDFT(Gain Compensator Discrete Fourier Transform) is presented. The 345 [kV] power system modeling data of the Republic of Korea by EMTP-RV is used to evaluate the performance of the proposed two kinds of RDWT(IRDWT and FRDWT) and GCDFT. The simulation results show that the frequency estimation technique based on FRDWT could be the optimal frequency measurement method, and thus can be applied to FDR(Fault Disturbance Recorder) for wide-area blackout protection or frequency measurement apparatus.

-An algorithm for fault detection and classification method for wide-area protection in Korean transmission systems is proposed. The modeling of 345-kV and 765-kV Korean power system transmission networks using the Electro Magnetic Transient Program -Restructured Version (EMTP-RV) is presented and the algorithm for fault detection and classification in transmission lines is developed. The proposed algorithm uses the Wavelet Transform (WT) and Singular Value Decomposition (SVD). The Singular value of Approximation coefficient (SA) and part Sum of Detail coefficient (SD) are introduced. The characteristics of the SA and SD at the fault conditions are analyzed and used in the algorithm for fault detection and classification. The validation of the proposed algorithm is verified by various simulation results.

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