Resonant Raman detection of macular pigment levels in the living human retina

We have used resonant Raman scattering as a novel, noninvasive in vivo optical technique to measure the concentration of macular carotenoid pigments in the living human retina. Using a backscattering geometry and resonant molecular excitation in the visible, we measure the Raman peaks that originate from the single- and double-bond stretch vibrations of the p -conjugated molecule's carbon backbone. The Raman signals scale linearly with carotenoid content, whereas the required laser excitation is well under safety limits for macular exposure. The Raman technique is objective and quantitative and may lead to a new method for rapid screening of carotenoid pigment levels in large human populations that are at risk for vision loss from age-related macular degeneration, the leading cause of blindness of the elderly in the United States.     

Resonance Raman effect in thiourea

Raman spectra of thiourea have been observed in H₂O and D₂O solutions with the exciting laser beams of 514.5, 488.0, 457.9, 363.8, 325.0, and 257.3 nm. The resonance Raman excitation profile of the 729-cm^?1 line has been examined in the region of the 237-nm absorption band ($\text{π}{}_{\mathrm{<mtext>CS</mtext>}}{}^1\text{← π}{}_{\mathrm{<mtext>CS</mtext>}}$) by use of a solvent shift of the absorption band instead of by changing the wavelength of the exciting beam. The depolarization degree of this line was measured and its overtone Raman line was also observed. On the basis of the results of these experiments, it has been concluded that the 729-cm^?1 Raman line, assignable to the CS stretching vibration, derives its intensity solely from the 237-nm band when it is excited at 257.3 or 325.0 nm. On exciting in the region 363.8–514.5 nm, however, contributions of the higher-frequency bands are predominant rather than the contribution from the 237-nm band. The Raman line at 1520 cm^?1 of thiourea-d₄ is assignable to the NCN antisymmetric stretching vibration. From its excitation profile, its intensity has been considered to come from a vibronic coupling between the excited electronic states of the 220-nm ($\text{π}{}_{\mathrm{<mtext>CS</mtext>}}{}^1\text{← π}{}_{\mathrm{<mtext>N</mtext>}}\text{? π}{}_{\mathrm{<mtext>N</mtext>}}$) and the 197-nm ($\text{π}{}_{\mathrm{<mtext>CS</mtext>}}{}^1\text{← π}{}_{\mathrm{<mtext>N</mtext>}}\text{+ π}{}_{\mathrm{<mtext>N</mtext>}}$) bands.     

拉曼镊子分析红酵母合成类胡萝卜素

利用拉曼镊子对红酵母合成类胡萝卜素进行分析,考查氮源和碳源对类胡萝卜素产量的影响.取发酵终点细胞,一部分用于紫外光谱法测定,另一部分用拉曼镊子检测.原始光谱经过背景扣除、基线校正等方法预处理,定性分析不同培养基培养细胞的平均光谱,类胡萝卜素的拉曼信号强度有明显不同;紫外检测结果和拉曼峰高数据有良好的相关性,拟合参数的相关系数分别达到0.907 8和0.9121;定量分析1508cm1峰高表明适宜红酵母细胞生长和类胡萝卜素合成的氮源和碳源分别是酵母粉+胰蛋百胨、葡萄糖.以上结果说明,拉曼镊子能提供红酵母胞内类胡萝卜索的含量信息,是实时检测红酵母细胞类胡萝卜素合成和优化发酵培养基的有效工具.     

Resonance Raman Spectroscopy of Porphin

We report and discuss Raman spectra of porphin. These were obtained by resonance effect, irradiating in the electronic band IV. Unexpected variations of vibrational band intensities and depolarization ratios were recorded on changing the excitation wavelength. Some implications on the symmetry types of the vibrations are discussed. Results are compared with current data from quasi-linear electronic spectra.     

In vitro analysis of immersed human tissues by Raman microspectroscopy

Raman microspectroscopy is a powerful tool for the analysis of tissue sections, providing a molecular map of the investigated samples. Nevertheless, data pre‐processing and, particularly, the removal of the broad background to the spectra remain problematic. Indeed, the physical origin of the background has not been satisfactorily determined. Using 785 nm as source in a confocal geometry, it is demonstrated for the example of the protein kappa‐elastin that the background and resulting quality of the recorded spectrum are dependent on the morphology of the sample. Whereas a fine powder yields a dominant broad background, compressed pellets and solution‐cast thin films produce, respectively, improved quality spectra and significantly reduced spectral background. As the chemical composition of the samples is identical, the background is ascribed to stray light due to diffuse scattering rather than an intrinsic photoluminescence. The recorded spectra from a tissue sample exhibit a large and spatially variable background, resulting in poorly defined spectral features. A significant reduction of the background signal as well as improvement of the spectral quality is achieved by immersion of the sample in water and measurement with an immersion objective. The significant improvement in signal to background is attributed to a reduction of the diffuse scattering due to a change in the effective morphology as a result of an improved index matching at the water/tissue interface compared to the air/tissue interface. Compared to sections measured in air, the background is reduced to that of the water, and pre‐processing is reduced to the subtraction of the substrate and water signal and correction for the instrument response, both of which are highly reproducible. Data pre‐processing is thus greatly simplified and the results significantly more reliable. Copyright © 2010 John Wiley & Sons, Ltd.     

Resonance Raman scattering in rare-earth tantalates

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 49, No. 6, pp. 998–1001, December, 1988.     

Photobleaching as a method of increasing the accuracy in measuring carotenoid concentration in human skin by Raman spectroscopy

It was shown experimentally that the effect of photobleaching in noninvasive measurement of the Raman spectra of light used in determining the carotenoid concentration in human skin can be used to increase measurement accuracy. Increased accuracy occurs as a consequence of a decrease in the measurable Raman spectra of the wideband fluorescent background intensity when a sample is irradiated by laser radiation. Furthermore, it was demonstrated that, for the spectra of skin from nine volunteers, the fluorescent background intensity can be decreased on average by a factor of 1.4, which leads to an increase in the signal-to-noise ratio for Raman lines of skin carotenoids by a factor of 1.2 on average. The kinetics of photobleaching of humans can be described by biexponential decay with a correlation coefficient close to unity, which agrees with the presented theoretical calculations.     

色素蛋白的共振Raman和FT-Raman光谱

色素蛋白的共振Ｒａｍａｎ和ＦＴ－Ｒａｍａｎ光谱李正强１卜凤泉２（１．吉林大学超分子结构与谱学开放实验室长春１３００２１）（２．白求恩医科大学应用基础医学研究所长春１３００２１）ＲｅｓｏｎａｎｃｅＲａｍａｎａｎｄＦＴ－ＲａｍａｎｏｆＣｈｒｏｍｏｐｈｏｒ...     

钠分子的共振喇曼散射

本文用80mW6238.2(?)的He-Ne激光激发钠蒸气,用一种新颖的棱镜反射光路,从后向首次观察到了56O0～8200(?)钠分子的共振喇曼谱.     

微过氧化酶的共振拉曼和表面增强拉曼光谱研究

采用电化学、共振拉曼和表面增强共振拉曼光谱研究了溶液态和吸附态微过氧化酶－１１（ＭＰ－１１）的电子传递及溶液和界面结构特征。结果表明,ＭＰ－１１在溶液中中心血红素铁以六配位状态存在,吸附于粗糙银电极表面时,则因ＭＰ－１１分子的重新取向而部分转化为五配位状态,氧化还原反应进一步促进这种配位状态的转化,并且配位状态也直接影响ＭＰ－１１的氧化还原性质。     

人乳腺癌组织阵列拉曼谱的模型成像研究

测量了人体乳腺管正常上皮组织及浸润性导管癌组织的阵列(Mapping)拉曼谱;利用作者前期建立的人体乳腺组织拉曼光谱模型,拟合了这些阵列谱,并将得到的归一化的拟合系数映射为灰度值,构建了乳腺组织的阵列拉曼谱模型成像。结果表明,这种模型成像具有较为明确的意义,尤其是细胞质、DNA、细胞间质基谱的拟合系数成像,较为清晰地呈现肌动蛋白、DNA及胶原的空间分布特征以及组织形态结构。与相关系数成像比较,模型成像给出了相似的结果。但模型成像对生化物质含量更敏感,成像分辨率更高。模型成像还显示癌变组织中细胞核明显增大、与细胞质相对比例明显增高,并为发展乳腺肿瘤拉曼诊断方法提供实验依据。     

Resonance Raman spectra of M-anions of metalloporphyrins

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 53, No. 4, pp. 576–584, October, 1990.     

Resonance Raman spectrum of selenium thin film

The resonance Raman spectrum of a selenium thin film at 20 K has been measured with the 514.5 nm excitation. A series of overtones, nv₇ (n = 1–5), v₂ + nv₇ (n = 0–3) and v₁₀ have been observed where v₇, v₂ and v₁₀ are the fundamental vibrations of the Se₈ ring molecule. The broadness of these bands at 20K suggests that the thin film contains randomly orientated Se₈ ring molecules.     

线性多烯分子的共振拉曼光谱

线性多烯分子是重要的光电材料,它还具有光采集、 光防护、 防癌、 抗癌功能,也是物理学、 化学理论研究的理想分子。 共振拉曼光谱是研究线性多烯分子最有力的工具。 本文总结了线性多烯分子共振拉曼光谱的特征及其与分子结构的关系,包括：电子光谱(紫外-可见吸收光谱)、 拉曼光谱的性质及与外场的关系;电子能隙对碳碳原子振动的调制作用;给出几个实验结果：温度降低、 溶剂密度增加、 溶液浓度降低等会使线性多烯分子结构有序增加,π电子能隙减小,使紫外-可见吸收光谱红移;π电子离域扩展,有效共轭长度增加,拉曼活性提高,拉曼光谱红移,拉曼截面增加。 振幅模型是研究线性多烯分子较理想的模型。     

共振拉曼光谱在体测量类胡萝卜素含量

类胡萝卜素是人体内重要的抗氧化剂,能够消除体内的自由基和其它有害氧分。研究表明类胡萝卜素含量与癌症、心血管疾病、老化等疾病发病率呈反比关系。目前检测方法为采用血清液相色谱检测方法,不能做到在体无损伤、实时测量。文章介绍了一种用于测量类胡萝卜素的新技术——共振拉曼光谱技术,具有在体无损伤、灵敏度高和实时检测等特点。该技术利用强度远小于美国ANSI Z136.1-2000标准的473 nm激光激发拇指中类胡萝卜素,产生强荧光和叠加在其上的弱共振拉曼光,通过测量拉曼散射光强度在体评估类胡萝卜素的含量。同时,利用组织通透技术,改善了测量信噪比。测量了不同饮食习惯志愿者的类胡萝卜素含量,说明其含量与其摄入量成正比。该技术在临床应用和科学研究等领域具有重要意义。     

Raman and surface‐enhanced Raman scattering in the study of human rotator cuff tissues after shock wave treatment

Important improvements of diseases of the rotator cuff supraspinatus tendons are seen after shock wave (SW) treatment. Neo‐angiogenesis stimulation and hypercellularization result from short periods of treatment. The present work is an attempt to provide a first approach to these bioprocesses, most likely associated with structural aspects resulting from biochemical changes brought about by the SW. Immunohistochemical data indicate that collagen areas in the tissues are influenced the most by the SW. Presence of additional collagens I and III by the SW treatment is inferred from an observed increase of the tissue's tinctorial properties. The tools selected for our studies are Raman spectroscopy and the ultrasensitive surface‐enhanced Raman scattering (SERS). Here we extract information from 1016 SERS spectra of 52 biopsies of human tendon tissues on Ag nanoparticles before and after the SW treatment. The spectral information is analyzed on the basis of Raman and SERS data of collagen types I and III and their most abundant amino acid components. SERS spectra of tissues reveal the presence of characteristic modes related mainly to amino acids. It has been found that the main differences between both tissue samples could be correlated with the structural conformational aspects of collagen. Copyright © 2011 John Wiley & Sons, Ltd.     

Resonance Raman Scattering of Mesoporphyrin IX Dimethylester in Solution

Resonance Raman spectra of Mesoporphyrin IX dimethylester in solution were obtained using various wavelengths in the region of electronic band IV. Vibrational data, as well as variations in the depolarization ratios and the band intensities with excitation wavelengths were compared to those previously obtained for porphin. The new data provide confirmation of the existence of three, most probably purely electronic transitions in band IV of both Mesoporphyrin IX dimethylester and porphin.