Browsing by Author "Mei-Fang Chen"

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Alpha-bungarotoxin binding to target cell in a developing visual system by carboxylated nanodiamond
(2008-05-21)
Liu, Kuang-Kai
;
Mei-Fang Chen
;
Chen, Po-Yi
;
Lee, Tony J. F.
;
Cheng, Chia-Liang
Biological molecules conjugating with nanoparticles are valuable for applications including bio-imaging, bio-detection, and bio-sensing. Nanometer-sized diamond particles have excellent electronic and chemical properties for bio-conjugation. In this study, we manipulated the carboxyl group produced on the surface of nanodiamond (carboxylated nanodiamond, cND) for conjugating with alpha-bungarotoxin (alpha-BTX), a neurotoxin derived from Bungarus multicinctus with specific blockade of alpha7-nicotinic acetylcholine receptor (alpha 7-nAChR). The electrostatic binding of cND-alpha-BTX was mediated by the negative charge of the cND and the positive charge of the alpha-BTX in physiological pH conditions. Sodium dodecyl sulfate-polyacrylamide gel analysis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI/TOF-MS) spectra displayed that alpha-BTX proteins were conjugated with cND particles via non-covalent bindings. The green fluorescence of the cND particles combining with the red fluorescence of tetramethylrhodamine-labeled a-BTX presented a yellow color at the same location, which indicated that alpha-BTX proteins were conjugated with cND particles. Xenopus laevis's oocytes expressed the human alpha 7-nAChR proteins by microinjection with alpha 7-nAChR mRNA. The cND-alpha-BTX complexes were bound to alpha 7-nAChR locating on the cell membrane of oocytes and human lung A549 cancer cells analyzed by laser scanning confocal microscopy. The choline-evoked alpha 7-nAChR-mediated inward currents of the oocytes were blocked by cND-alpha-BTX complexes in a concentration-dependent manner using two-electrode voltage-clamp recording. Furthermore, the fluorescence intensity of cND-alpha-BTX binding on A549 cells could be quantified by flow cytometry. These results indicate that cND-conjugated alpha-BTX still preserves its biological activity in blocking the function of alpha 7-nAChR, and provide a visual system showing the binding of alpha-BTX to alpha 7-nAChR.
以模糊規則為基礎之資料探勘分析消費者於產品因子之偏好
(2005-10-01)
胡宜中
;
陳美芳
;
Yi-Chung Hu
;
Mei-Fang Chen
;
Institute of Business and Management
藉由消費者對產品與產品各因子的偏好評估，本文提出一以模糊規則為基礎之資料探勘方法，可以由所收集之問卷中找出簡化的模糊規則，並找出定義於產品因子上的模糊語意值組合及其相對應之消費者效用。本文的主要目的在於發展一有用之決策分析工具，使決策者可應用前述之資訊以制定適當之行銷或經營策略，而在做法上係發展以基因演算法為基礎之資料探勘技術，決定一些使用者難以設定之參數，以自所收集之資料中找出前鑑部與後鑑部分別為語意值組合與該組合相對應之消費者效用之簡化模糊規則。此外，產品的意義並不限定為實物，而是廣泛的解釋為一切可被評估之對象。本文以速食店服務品質評估之問卷資料為實驗例，由資料中找出具較大或較小消費者效用之語意值組合並進行分析，以說明所提出之方法在支援決策分析上的實用性與可行性。