目的 以核磁共振(NMR)分析不同年齡SD大鼠尿樣中內(nèi)源性代謝物的改變實(shí)驗(yàn)數(shù)據(jù)為基礎(chǔ),提出新的積分方法.方法 通過在原有固定步長(zhǎng)積分的基礎(chǔ)上引入步長(zhǎng)變動(dòng)區(qū)間,使數(shù)據(jù)積分區(qū)間可以根據(jù)峰的位置進(jìn)行一定范圍的調(diào)整,形成變步長(zhǎng)積分方法.以固定步長(zhǎng)和變步長(zhǎng)積分方法,對(duì)實(shí)際實(shí)驗(yàn)數(shù)據(jù)進(jìn)行比較研究.結(jié)果 變步長(zhǎng)積分方法既能夠增強(qiáng)樣品聚類能力,能夠減少差異代謝物指認(rèn)缺失現(xiàn)象的發(fā)生.結(jié)論 變步長(zhǎng)積分方法克服了固定步長(zhǎng)積分方法存在的不足,解決了固定步長(zhǎng)積分方法不能夠同時(shí)兼顧圖譜分辨率和減少由于環(huán)境引起的化學(xué)位移變化的矛盾.

Objective To present a new integrating algorithm for NMR analysis based on the data of endogenous metabolites in urine which changed by the age of SD rats. Methods This new algorithm—variable step integrating algorithm (VSIA) is by adding variable step range on fixed step, thus the integrating range can be adjusted by different peak widths. The integral method of VSIA included four procedures such as denoising of sample data, recognition of peak-valley point, domain integral based on input parameters, and output data of integral domain. In this paper, we compared VSIA and fixed step algorithm, using pattern recognitions, principal component analysis (PCA), and partial least squares-discriminate analysis (PLS-DA), to analyze the integral data from the NMR spectra. Results VSIA can significantly enhance the aggregative of different group samples, and can also reduce the loss of different metabolites caused by naive data preprocessing. By integrating effectively according to the signal peak position, VSIA can both enhance the spectrum resolution and reduce the chemical shift changes caused by environment, thus the loss of fixed step algorithm could be made up. Conclusion This study suggests that VSIA could be applied to metabonomic studies, and also could be extended to the other multi- dimensional data processing analysis.

遼寧省自然科學(xué)基金項(xiàng)目(20072113);遼寧省科學(xué)技術(shù)項(xiàng)目(2012225107);沈陽(yáng)市科技計(jì)劃項(xiàng)目(F12-277-1-79)