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肿瘤发展过程中类胡萝卜素、卟啉代谢的模拟及其荧光分析 总被引:2,自引:1,他引:1
通过肿瘤发展过程中类胡萝卜素、卟啉代谢的模拟及其荧光分析,研究了类胡萝卜素对血清荧光法癌诊断的影响。采取肘静脉血制取血清,采用光致发光的方法研究了血清中的发光中心,模拟癌发展过程中类胡萝卜素和卟啉的代谢水平对血清荧光癌诊断方法的影响。血清中主要的发光是来自具有共轭基团的血清蛋白、类胡萝卜素和卟啉的电子跃迁。随着血清中类胡萝卜素含量的增加,520nm荧光峰强度提高,614nm附近的波谷亦升高,诊断I值(荧光强度的比值,见引言中公式(1))会下降即降低了癌诊断的阳性率。 相似文献
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血清浓度变化对血清荧光光谱的影响 总被引:1,自引:0,他引:1
光谱分析技术应用于血液的某些疾病诊断具有方便、快速的特点.文章采用日本岛津荧光光度计RF5301,研究了血清荧光光谱随血清浓度变化的规律,为通过血液分析进行疾病诊断提供了实验依据.实验结果表明:在不同波长的激发光激励下产生的荧光光谱不同,当用220,230,310~420 nm波长的光激发时,血清的荧光强度随着血清浓度的增加越来越大;而采用240~300 nm波长的光激发时,血清的荧光强度随着血清浓度的增加变得越来越小.实验还发现:当采用220,230,310~420 nrn波长的光激发时,血清的浓度猝灭和吸收作用不明显,主要是激发出的荧光起作用;采用240~300 nm波长的光激发时,血清浓度猝灭和吸收作用明显,导致荧光强度随着血清浓度的增加变得越来越弱.这对研究血清荧光光谱时血清浓度的选择具有参考价值. 相似文献
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不同波长激发光对血清荧光光谱影响的实验研究 总被引:2,自引:0,他引:2
采用日本岛津荧光光度计RF5301,研究了血清的荧光光谱与激发光波长的关系。实验结果表明:在不同波长的紫外光激励下,血清产生的荧光光谱线型及峰值波长基本相同,与激励光波长无关,但荧光峰强度随激励光波长变化而变化。血清的荧光光谱有两个较强的荧光发射区,其中第一个发射区处于300~410 nm,第二个发射区处于410~530 nm。当激发光波长小于310 nm,荧光主要集中在第一发射区,荧光峰位于330和370 nm处,并产生竞争现象。当激发光波长大于250 nm时,只出现330 nm处的荧光峰,其最佳激励光波长为300 nm;当激发光波长大于320 nm,第一发射区的荧光变弱,在第二发射区的荧光变强,荧光峰位于452 nm。此研究为血液的光谱特性研究提供了实验依据,对光诱导荧光光谱诊断技术中激发光波长的选择具有一定的参考价值。 相似文献
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血清自体荧光光谱联合肿瘤标志物群在肺癌诊断中的价值 总被引:3,自引:0,他引:3
血清自体荧光光谱可以反映血清中癌细胞在代谢过程中发生的异常改变而导致的血清中荧光物质的成分、含量及微环境的变化,可作为癌症辅助诊断的一种新方法。利用荧光光谱分析技术,探讨了肺癌、肺良性疾病以及正常人血清的荧光光谱的异同,建立了血清荧光光谱检测的方法。同时联合肿瘤标志物群CEA, NSE, SCC-Ag, CYFRA21-1和p16甲基化,并运用人工神经网络技术和Fisher线性判别分析法分别建立了肺癌的诊断预测模型,并用ROC判别法对其预测结果进行比较。结果表明,荧光光谱联合肿瘤标志物建立的人工神经网络模型的预测效果优于单纯的荧光光谱神经网络模型,判别效果优于Fisher线性判别分析。 相似文献
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采用荧光光谱结合组织病理学方法,研究脉冲电磁场辐照后大鼠脑组织结构的变化情况,探讨血清荧光光谱变化与脑损伤的关系。将雄性SD大鼠随机分为假辐照组和辐照组,辐照组暴露于宽频脉冲电磁场,在辐照后5个不同时间点采集血样,分析血清荧光光谱和S100B蛋白表达情况,并观察脑组织病理切片。结果发现,脑损伤程度和辐射剂量有一定的关系,辐射剂量越大,损伤越严重,其变化趋势和S100B蛋白表达、脑组织病理观察结果一致。说明血清荧光光谱法可能适用于对电磁脉冲作用后生物体和脑损伤效应的分析。 相似文献
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时间分辨光谱法用于离体人肺鳞癌,腺癌及正常组织的荧光寿命测量 总被引:1,自引:1,他引:0
用Nd:YAG倍频光532.0nm泵浦DCM染料输出的632.8nm激光作激发源,通过时间分辨法测得离体人肺腺癌,鳞癌及正常组织的特征峰荧光寿命分别为5.1,5.6和6.3ns实验结果表明:肿瘤组织的荧光寿命总小于正常组织的荧光寿命,这种方法将有可能用于精确诊断和定位肿瘤。 相似文献
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Kudrinskiy AA Krutyakov YA Olenin AY Romanovskaya GI Vasilyeva SY Lisichkin GV 《Journal of fluorescence》2009,19(3):473-478
The fluorescence of pyrene adsorbed onto the surface of the cetyltrimethylammonium-coated silver nanoparticles was studied.
Pyrene molecules adsorbed on freshly prepared silver particles were found to be in close proximity to silver surface thus
providing the possibility of energy transfer from excited pyrene to silver cores of the particles. In that case along with
the expected fluorescence of pyrene we observed the fluorescence of the silver nanoparticles induced by the excited pyrene
molecules. In due course the restructuring of the cetyltrimethylammonium layer resulted in moving of pyrene molecules away
from silver surface and simultaneous disappearance of the silver nanoparticles fluorescence band. These data strongly support
the recent hypothesis of fluorophore-plasmon coupled emission. 相似文献
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The sensitized fluorescence and laser emissions of dye mixtures; (I) coumarin 102 (donor) and acridine orange (acceptor) and (II) coumarin 47 (donor) and acridine orange (acceptor) with Hg-lamp and N2 laser, have been measured as a function of dye concentration and of the pump power (N2 laser). Acridine orange which does not lase by itself on excitation with N2 laser, lases efficiently in the presence of 7-amino-coumarins via singlet-singlet energy transfer. Energy transfer rate constants and critical distances have been estimated from fluorescence intensity and lifetime measurements. The performance of energy transfer dye lasers (ETDLs) are discussed in terms of spectral characteristics of the dyes and their penetration depths. 相似文献
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Total internal reflection fluorescence (TIRF) spectroscopy was used to investigate the adsorption behavior of meso-tetrakis(p-sulfonatophenyl)porphyrin (TPPS) at the glass/water interface in the presence of a cationic surfactant (cetyltrimethylammonium
bromide, CTAB) far below the critical micelle concentration. The adsorption model of TPPS at the glass/water interface in
the presence of low concentration of CTAB was proposed, which was different from the adsorption of TPPS in the presence of
micelles of CTAB at the glass/water interface. TPPS and CTAB did not form stable complex at the interface in dilute system.
The interfacial species of TPPS were analyzed by comparing the spectra of TPPS at the glass/water interface and in the aqueous
phase. The influences of the TPPS concentration, the CTAB concentration, and the pH values on the interfacial fluorescence
spectra and intensities were studied. It was demonstrated that electrostatic interaction and hydrophobicity performed an important
role on the adsorption of TPPS in the presence of CTAB. The different effects of TPPS concentration on the adsorption behaviour
of TPPS at different pH were observed for the first time. It was found that the adsorption isotherms of TPPS at glass/water
interface could fit Freundlich equation at pH 7.1. 相似文献
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In view of the discrepancies between the values available in the literature for the photophysical parameters of tetraazaporphin
in solutions, we measured its quantum yield and duration of fluorescence in a number of solvents. It has been found that alcohols
(isobutanol and isopropanol) quench the fluorescence appreciably. For a solution in toluene — a stable chemically inactive
and low-polar solvent — the measured quantum yield of the fluorescence of tetraazaporphin is equal to 0.180 ± 0.015 and its
duration is 3.4 ± 0.1 nsec.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 5, pp. 697–699, September–October, 2005. 相似文献
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测定了粉末罗丹明101(Rhodamine 101)及其在溶剂(甲醇、乙醇、水的混合液)中的高压荧光光谱。结果表明,粉末样品和溶液样品在高压下的发光性质有很大的区别。对于粉末样品,随着压力的增加,Rhodamine 101的荧光强度下降很快,在大约8 GPa时荧光峰几乎消失;伴随着荧光强度的变化,荧光峰峰位发生了显著红移(8 GPa内红移了近100 nm)。对于溶液样品,其荧光强度随压力的增加降低较慢,到13 GPa时,强度约为常压的10%,荧光峰峰位红移较小(13 GPa内红移约50 nm)。在压力作用下,Rhodamine 101分子结构的变化和特殊的溶剂效应,分别是影响其在粉末状态和溶液中荧光性质的主要因素。 相似文献
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为了指导水稻的田间施肥,解决因过量施肥造成资源的大量浪费以及环境污染,特别是水体富营养化等问题,搭建了基于紫外激光诱导荧光技术的荧光光谱探测系统,以研究水稻叶片的氮水平与荧光强度的相关性。文中先用植物营养测定仪(TYS-3N)测定水稻叶片氮含量和叶绿素含量(样本为水稻分蘖期的倒二叶,采集于中国江汉平原地区),再用搭建的测量系统采集了不同氮水平的荧光光谱。获得了不同氮水平下水稻叶片的荧光光谱数据库,分析了荧光光谱参数F740/F685(为峰值740,685 nm处的荧光强度比)与氮水平的相关性,发现氮含量的变化对水稻叶片荧光光谱特性影响明显。通过该实验验证了荧光参数的峰值比F740/F685与氮含量呈明显的线性正相关,相关系数(r)为0.871 8,均方根误差(RMSE)为0.076 82。实验表明采用激光诱导荧光光谱探测技术具有快速无损等优点,且有一定潜力用于定量测量植被营养元素的含量,为采用荧光技术对农作物施氮管理提供了支持。 相似文献
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用970CRT荧光分光光度计分别采集了不同pH值下番茄红素-丙酮溶液的荧光光谱,并测量了这些溶液的荧光强度随时间的变化情况。通过对数据的分析得出:与没有经过酸碱滴定的番茄红素-丙酮溶液相比,酸性条件下,荧光强度相对较小,而在碱性条件下,其荧光强度相对较大;pH=1时,番茄红素-丙酮溶液的荧光峰位发生了红移,而pH=11和pH=13时,其荧光峰位又有不同程度的蓝移;在强酸和强碱环境中番茄红素不稳定,其荧光峰强度下降较快,这是因为在强酸环境下重原子效应的影响,和强碱环境下番茄红素参加了阴离子聚合反应;番茄红素在有机溶剂和弱碱环境下比较稳定,其荧光强度下降较慢。 相似文献
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Kinetic analysis of the energy level scheme of a dye molecule yields expression for the fluorescence quantum yield. The quantum
yield is dependent on molecular parameters and laser pulse characteristics. Calculations show quenching of fluorescence quantum
yield due to excited state absorption. Earlier studies on quenching of fluorescence have been discussed quantitatively under
an optically thin approximation. 相似文献