Absorption coefficient and purine photobleaching rate in colon mucosa during resonance Raman spectroscopy at 251 nm
Absorption coefficient and purine photobleaching rate in colon mucosa during resonance Raman spectroscopy at 251 nm
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DOI：
10.1364/ao.40.006396
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发表时间：
2001-12-01
期刊：
影响因子：
1.9
通讯作者：
Boustany, NN
中科院分区：
文献类型：
--
作者：
Boustany, NN
与较长波长的光谱相比，生物组织的紫外共振拉曼（UVRR）光谱的典型属性是较高的吸收系数μ和较高的光漂白速率κ。本研究的目的是在251 nm处测量人体结肠组织UVRR光谱期间的μ和κ。μ用于估计激发光的穿透深度，kappa用于预测由于作为激光能量密度和组织厚度的函数的光漂白引起的信号降低速率。通过描述三态跃迁模型对由嘌呤UVRR信号组成的实验数据进行方程拟合，得到mu = 0.0169 +/- 0.0023 mum（1）和kappa = 0.572 +/- 0.168（mJ/mum（2））（-1）。当功率P < 1 mW时，kappa值与功率P无关，但功率越高，光漂白率越高。正如模型预测的那样，由于光漂白引起的信号下降随着样品厚度的增加而变慢。(C)2001年美国光学学会。
In contrast to spectroscopy at longer wavelengths, typical attributes of ultraviolet resonance Raman (UVRR) spectroscopy of biologic tissue are higher absorption coefficient, mu, and higher photobleaching rate, kappa. This study was aimed at measuring mu and kappa during UVRR spectroscopy of human colon tissue at 251 nm. mu was used to estimate the penetration depth of the excitation light, kappa was used to predict the rate of signal decrease that was due to photobleaching as a function of laser fluence and tissue thickness. The fitting of the equations through description of a three-state transition model to experimental data that consisted of a purine UVRR signal gave mu = 0.0169 +/- 0.0023 mum (1) and kappa = 0.572 +/- 0.168 (mJ/mum(2))(-1). kappa remained independent of power P for P < 1 mW, but higher power values resulted in a higher photobleaching rate. As predicted by the model, signal decrease that was due to photobleaching was slower as sample thickness was increased. (C) 2001 Optical Society of America.