华南师范大学生物光子学研究院激光生命科学教育部重点实验室, 广东 广州 510631
精确的血迹年龄预测具有重大的法医学价值。利用可见反射光谱技术与偏最小二乘法(PLS)相结合分析预测血迹年龄。遗传算法与偏最小二乘法相结合被用来选择有效光谱区间。与全光谱PLS 模型相比较，建立在优化光谱区间的遗传区间偏最小二乘法(GA-iPLS)模型具有更好的预测能力。结果表明GA-iPLS 能合理地选择有效光谱区间，提高预测能力。在考虑取自不同个体血迹特异性的情况下，建立在2.00~48.00 h时间段和48.00~1080.00 h时间段的GA-iPLS 模型的相关系数(Rp)、预测标准误差(RMSEP)和剩余预测偏差(RPD)分别为0.9949/0.9924、1.59 h/43.56 h、10.32/8.42。两个GA-iPLS模型的结合可代替建立在2.00~1080.00 h时间段的GA-iPLS模型精确预测2.00~1080.00 h 时间段的血迹年龄。结果表明可见反射光谱与GA-iPLS 模型在法医学领域可成为一种可靠的精确预测血迹年龄的方法。
光谱学 年龄预测 遗传区间偏最小二乘法 可见反射光谱 法医学
华南师范大学生物光子学研究院, 广东 广州 510631
在快速发展的中国,有机食品、绿色食品和无公害食品在产地环境、生产规程、加工、包装,尤其是生产资料的使用等方面都有严格区分,导致检验和认证需要花费大量的人力、物力、财力和时间.因此我们需要一种方便、精确的检测技术.基于化学计量学,本研究首次利用可见-近红外反射光谱快速检测有机胡萝卜、绿色胡萝卜和无公害胡萝卜.选择最佳区间(650-700 nm),三种分类模型包括主成分分析结合k均值聚类、主成分分析结合线性判别分析、反向传播神经网络鉴别126个胡萝卜样本的准确率分别为93.65%、100%,和98.41%.结果表明,可见-近红外光谱结合化学计量学技术可以有效地验证有机胡萝卜、绿色胡萝卜和无污染胡萝卜.为质量检验机构提供了一个可行的检测方法,从而促进包括有机食品、绿色食品、无公害食品等安全食品的发展.
有机胡萝卜 绿色胡萝卜 无公害胡萝卜 认证 可见-近红外反射光谱 化学计量学 organic carrots green carrots non-pollution carrots certification visible-near infrared reflectance spectroscopy chemometrics
Photonic Chinese Medicine Laboratory, Institute of Biophotonics, South China Normal University, Guangdong, Guangzhou 510631, China
1 华南师范大学光子中医学实验室, 广东 广州 510631
2 赣南师范学院物理与电子信息学院, 江西 赣州 341000
采用拉曼光谱作为分析手段,以近红外激光785 nm波长激发,获得了真、假一百元人民币在固定人像水印、全息开窗安全线、隐形面额数字和光变油墨数字等处的谱图。发现真币与假币的谱图有明显差别,而且不同来源的假币的拉曼光谱也存在着可分辨的差异。研究表明,利用拉曼光谱的分子指纹和微区分析能力,不仅对伪造、变造人民币的识别有重要价值,而且可以分辨不同来源的假币。
光谱学 光谱分析 假币鉴别 拉曼光谱 近红外激光
Author Affiliations
Abstract
Photonic Chinese Medicine Lab, South China Normal University, Guangzhou 5106312School of Physics and Electronic Information Science, Gannan Teachers College, Ganzhou 3410003Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510631
A·C mismatches are studied by Raman spectral characterization of PolyA, PolyC, and their equimolar complex in solution of 0.14 mol/L Na+, pH7.0. Experimental results show that A·C mismatches occur to be A/B (mainly A) conformers, and unlike Watson-Crick base pairing, this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H2 and adenine N7. The formation of A·C complex makes the base stacking interactions much stronger, and conformation of the backbone more ordered, which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.
A·C碱基错配对 喇曼光谱 多聚腺嘌呤核苷酸 多聚胞嘧啶核苷酸 170.5660 Raman spectroscopy 300.6170 Spectra 300.6330 Spectroscopy, inelastic scattering including Raman 300.6450 Spectroscopy, Raman 300.6390 Spectroscopy, molecular Chinese Optics Letters
2008, 6(1): 0161
Author Affiliations
Abstract
1 Institute of Laser Life Sciences, South China Normal University, Guangzhou 510631
2 Department of Medical Oncology, Cancer Center, Sun Yat-Sen University of Medical Sciences, Guangzhou 510060
We used Raman spectroscopy to study the conformational changes of DNA induced by Cd2+ ions in different Cd2+ concentrations solution. The experimental results show that when the Cd^(2+)/PO^(-)_(2) ratio R increased from 0 to 3.0, the band 835.0 cm^(-1) shifted about 8 cm^(-1), and the overlapping spectra of 1446.0 and 1461.0 cm^(-1) separated and moved to 1441.0 and 1458.0 cm^(-1), respectively. This indicates that the conformation of DNA has changed from a "normal" B-form to a "modified" B'-form. At the same time, changes of other bands demonstrate that parts of base stacking collapse and some hydrogen bonds between AT are disrupted, AT base pairs are damaged more larger than GC base pairs.
300.6170 spectra 300.6230 spectroscopy coherent anti-Stokes Raman scattering 300.6350 spectroscopy ionization 300.6390 spectroscopy molecular Chinese Optics Letters
2004, 2(3): 03154
