• Journal of Intelligence and Information Systems
• /
• v.4 no.2
• /
• pp.1-21
• /
• 1998

귀납적 학습방법들의 분류성능을 비교 평가하기 위하여 대표적 분류문제의 하나인 신용평가 문제를 사용하였다. 분류기로서 사용된 귀납적 학습방법론들은 통계학의 다변량 판별분석(MDA), 기계학습 분야의 C4.5, 신경망의 다계층 퍼셉트론(MLP) 및 Cascade Correlation Network(CCN)의 4 가지이며, 학습자료로는 국내 3개 신용평가기관이 발표한 신용등급 및 공포된 재무제표를 사용하였다. 신용등급 예측의 정확도에 의한 분류성능을 평가하였는데 연도별 평가와 시계열 평가의 두 가지를 실시하였다. Cascade Correlation Network이 가장 좋은 분류성능을 보였지만 4가지 분류기들 사이에 통계적으로 유의한 차이는 발견되지 않았다. 이는 사용된 학습자료가 갖는 한계로 인한 것으로 추정되지만, 성능평가 과정에 있어 학습자료의 전처리 과정이 분류성과의 제고에 매우 유효함이 입증되었다.

• Journal of The Korean Astronomical Society
• /
• v.31 no.2
• /
• pp.117-125
• /
• 1998

We have observed the 10-9 transitions of $HC_3N$ and its $^{13}C$ substitutes ($H^{13}CCCN,\;HC^{13}CCN$, and $HCC^{13}CN$), and the vibration ally excited 12-11 ($v_r=1$) $HC_3N$ transition toward the Sgr B2 molecular cloud. The observed $HC_3N$ emission shows an elongated shape around the Principal Cloud ($\~$4.5 pc in R.A. $\times$ 7.4 pc in Decl.). The optically thin $H^{13}CCCN$ line peaks around the (N) core and we derive the total column density $N(H^{13}CCCN) = 4 {\times}10^{13} cm^{-2}$ at this position. Toward the 2' N cloud which shows the peculiar chemistry, the $HC_3N$ lines show enhancements compared to the extended envelope. The shocks of the 2' N may have resulted in the enhancement of $HC_3N$. The hot component of $HC_3N$ is strongly concentrated around the (N) core and its HPW is $\~$0.9 pc in diameter. We derive the lower limit of the abundance ratio $N(HC_3N)/N(H^{13}CCCN)$ to be larger than 40 in most regions except the (M) and (N) cores. The fractionation processes of $^{13}C $at this region may not be as effective as previously reported.

• Molecules and Cells
• /
• v.39 no.12
• /
• pp.909-914
• /
• 2016

Epithelial-mesenchymal transition (EMT) is a critical step in the acquisition of the migratory and invasive capabilities associated with metastatic competence. Cysteine-rich protein 61 (CCN1/Cyr61) has been implicated as an important mediator in the proliferation and metastasis of breast cancer. Hence, Cyr61 and associated pathways are attractive targets for therapeutic interventions directed against the EMT. In the present study, we report that baicalein significantly inhibits the expression of Cyr61 and migration and invasion of MDA-MB231 human breast cancer cells. Exposure to baicalein led to increased E-cadherin expression, possibly due to the ubiquitination of Snail and Slug, which was mediated by the Cyr61/Akt/glycogen synthase kinase $3{\beta}$ ($GSK3{\beta}$) pathway. Further analysis revealed that baicalein inhibited the expression of lysyl oxidase like-2 (LOXL-2), which is a functional collaborator of Snail and Slug, and subsequently attenuated the direct interaction between LOXL-2 and Snail or Slug, thereby enhancing $GSK3{\beta}$-dependent Snail and Slug degradation. Our findings provide new insights into the antimetastatic mechanism of baicalein and may contribute to its beneficial use in breast cancer therapies.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.7
• /
• pp.2659-2664
• /
• 2015

Background: To examine the expression of cysteine-rich 61 (Cyr61/CCN1) protein in laryngeal squamouscell carcinoma (LSCC) tissues, and its relationship with the tumor epithelial-mesenchymal transition (EMT), invasion, metastasis, and prognosis. Materials and Methods: Immunohistochemistry was used to detect the expressions of Cyr61, Vimentin (Vim), and E-cadherin (E-cad) in 88 cases of LSCC tissues and 30 cases of tumor-adjacent normal tissues. Vim and E-cad were used as mesenchymal and epithelial markers, respectively, to determine the relationship between Cyr61 expression and the EMT of LSCC cells. In addition, clinical and histopathological data were combined to analyze the relationship between the positive-expression rates of Cyr61, Vim and E-cad and LSCC invasion, metastasis and prognosis. Results: In LSCC tissues, Vim expression rate was significantly higher than that of the tumor-adjacent tissues, whereas E-cad expression rate was significantly lower than that of the tumor-adjacent tissues. The Vim expression rate was significantly higher in stages T3 and T4 than in stages T1 and T2 LSCC tissues, whereas E-cad expression rate was significantly lower in stages T3 and T4 than in stages T1 and T2 LSCC tissues. Compared to the group without lymph node metastasis, the Vim expression rate was significantly higher and the E-cad expression rate was significantly lower in the group with lymph node metastasis. The expression rate of Cyr61 was significantly higher in LSCC tissues than in the tumor-adjacent normal tissues. In addition, the Cyr61 expression rate was higher in stages T3 and T4 than in stages T1 and T2 LSCC, and higher in the group with lymph node metastasis than in the group without lymph node metastasis. The Vim expression rate was significantly higher in the Cyr61 positive group than in the Cyr61 negative group, whereas the E-cad expression rate was significantly higher in the Cyr61 negative group than in the Cyr61 positive group. Survival analysis indicated that survival rates of Cyr61 positive, Vim positive and E-cad negative groups were significantly lower than that of Cyr61 negative, Vim negative and E-cad positive groups, respectively. Conclusions: Cyr61 expression is closely associated with LSCC invasion and lymph node metastasis. Overexpression of Cyr61 may induce EMT and therefore leads to LSCC invasion and metastasis and poor prognosis. Cyr61 may become a new maker for clinical prediction of LSCC invasion and metastasis and a new target for LSCC treatment.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.8
• /
• pp.1252-1260
• /
• 2020

(R)-2-(4-hydroxyphenoxy)propionic acid (HPOPA) is a key intermediate for the preparation of aryloxyphenoxypropionic acid herbicides (R-isomer). In order to improve the HPOPA production from the substrate (R)-2-phenoxypropionic acid (POPA) with Beauveria bassiana CCN-A7, static cultivation and H₂O₂ addition were attempted and found to be conducive to the task at hand. This is the first report on HPOPA production under static cultivation and reactive oxygen species (ROS) induction. On this premise, the cultivation conditions and fermentation medium compositions were optimized. As a result, the optimal carbon source, organic nitrogen source, and inorganic nitrogen source were determined to be glucose, peptone, and ammonium sulfate, respectively. The optimal inoculum size and fermentation temperature were 13.3% and 28℃, respectively. The significant factors including glucose, peptone, and H₂O₂, identified based on Plackett-Burman design, were further optimized through Central Composite Design (CCD). The optimal concentrations were as follows: glucose 38.81 g/l, peptone 7.28 g/l, and H₂O₂ 1.08 g/l/100 ml. Under the optimized conditions, HPOPA titer was improved from 9.60 g/l to 19.53 g/l, representing an increase of 2.03-fold. The results obtained in this work will provide novel strategies for improving the biosynthesis of hydroxy aromatics.