Evolution of past enamel technology and metal conservation issues: the case of two Byzantine style bindings

The results of a Raman spectroscopic study of the cloisonne’ and basse‐taille enamels, which beautify two Byzantine style bindings from the Marciana Library (Venice), namely the Lat. III,111 and the MsGR.I.53 codexes, are presented in this work. The first binding dates back to the 13th century and was subject to an early restoration work in the 14th century, when new enamels substituted four originals. The second binding, from the 15th century, shows a lower number of enamels, all originals, and with a larger color palette. The white and yellow enamels of both codexes were successfully characterized and the red ones, where hematite was not used. Interestingly the white and yellow color of the 13th century enamels of the Lat. III,111 codex has been obtained by an ancient technique of the glass technology, which was already obsolete in the 13th century, and is based on the use of calcium antimonate and Naples yellow. The white color in the other binding's enamels have been instead obtained by using cassiterite, according to the tradition of the time. Cassiterite was also mixed to Naples yellow in the enamels of the MsGR.I.53 codex, to change the yellow hue. The identification of agents determining some colors is instead uncertain or not feasible by Raman spectroscopy. The transparency of the 14th century enamels of the Lat. III,111 codex has allowed the comparison of metal degradation below the enamels and in regions exposed to the atmosphere. Copyright © 2012 John Wiley & Sons, Ltd.     

高效液相色谱法检测化妆品中着色剂罗丹明B、金光红C和颜料红57

采用N,N-二甲基甲酰胺提取样品中的待测物,建立了化妆品中禁、限用着色剂罗丹明B、颜料红57和金光红c的高效液相色谱检测方法。以XDB-C18柱为分析柱,5mmol／L四丁基氢氧化铵-氢氧化钾水溶液（磷酸调至pH7．00）和甲醇为流动相,梯度洗脱。550am（罗丹明B）和480nm（颜料红57和金光红C）为检测波长,柱温30℃,流速1．0mL／min,保留时间定性,外标法定量。结果表明在0．25-20mg／L（罗丹明B和金光红C）、0．5-40mg／L（颜料红57）浓度范围内线性关系良好,检出限分别为5,20,20mg／kg（S／N=10）,实际样品中的加标回收率分别为94．8％～100．5％,95．1％～103．1％,82．5％-90．5％,相对标准偏差为0．9％～4．6％。该方法前处理简单、易操作,检测结果准确可靠。能够满足化妆品中这3种着色剂的检测要求和监管需要。     

水稻叶片叶绿素、类胡萝卜素含量估算的归一化色素指数研究

测定了水稻叶片的高光谱反射率,以及相应的叶绿素、类胡萝卜素含量,采用一种将350～2 500 nm范围内所有光谱波段两两组合的方法,构建所有可能的归一化比值色素指数,并建立这些指数与叶绿素、类胡萝卜素含量的统计模型,然后将构成最佳模型的指数确定为最适合相应色素估算的指数,并进行验证以及与已知归一化色素指数进行了比较。结果表明,本研究所给出基于叶片水平的色素指数(R_{1 729}-R₇₀₇)/(R_{1 729}＋R₇₀₇),(R_{1 554}-R₅₇₂)/(R_{1 554}＋R₅₇₂),(R_{1 729}-R₇₀₆)/(R_{1 729}＋R₇₀₆),(R_{1 536}-R₇₀₇)/(R_{1 536}＋R₇₀₇)可以较好地估算叶绿素、类胡萝卜素含量。构成这些色素指数的指数波段主要位于700 nm附近,其次为绿光长波区域;构成指数的参照波段主要位于短波红外区域。这说明短波红外区域在色素指数的构建中也有重要作用。这些色素指数对叶绿素、类胡萝卜素含量的估算效果一般要好于各已知的归一化比值色素指数,或者与最好的已知色素指数估算效果相当。     

含蒽醌基单偶氮染料光电导性质构效研究

由1-氨基蒽醌和不同偶合基合成了九个含蒽醌基的单偶氮染料,并对其进行了 元素分析、红外光谱和紫外光谱表征。紫外光谱研究结果表明,偶合基酰胺芳环上 取代基对偶氮染料的吸收光谱影响不大。当偶合基由2-羟基-3-氨替酰胺萘酚（ Azol～8)变为2-羟基-11氢-苯并咔唑-3-氨替酰胺萘酚（Azo9)时,偶氮染料的吸收 红移了130 nm,最大吸收出现在662 nm处,成为近红外染料。偶氮染料光电导性质 的研究表,偶合基酰胺芳环上取代基吸电子效应越强,光敏性越好,且与Hammett 常数σ有良好的相关性。值得注意的是萘环上扩大一个咔唑环（Azo9),使偶氮染 料的光敏性提高了几十倍,表明在萘环上扩大共轭环是提高偶氮染料光敏性的一个 良好途径。     

纳米钴蓝颜料的微乳法制备及其表征

纳米粒子;微乳液;量子尺寸效应;纳米钴蓝颜料的微乳法制备及其表征     

酸度分布-吸收光谱法用于灰色体系中食用色素的定量分析

利用合成色素随ｐＨ变化的人分布分数曲线和吸收光谱构成两维波谱信息,建立了灰色体系中色素的定量分析方法。约束背景双线性分解法（ＣＢＢＬ）结合数值遗传算法（ＮＧＡ）用于两维矩阵的数据处理。推导了型体总数与两维矩阵的有效秩之间的关系。吸光度矩阵的主成分数根据残余矩阵的残差平方和噪声水平相比较 确定,对标准样品及模拟灰色体系样品的研究表明该法确定的主成分数与理论值一致。对胭脂红、日落黄和柠檬黄的模拟灰色休     

溴胺酸Ullmann缩合反应工艺

采用强酸阳离子交换树脂-乙醇-铜粉催化体系代替传统工艺中硫酸-水-铜粉催化体系,对溴胺酸进行Ullmann缩合反应。考察了强酸离子交换树脂用量、有机溶剂种类及反应温度等因素对反应收率的影响。结果表明,在V(乙醇)∶V(水)=9∶1介质中,在溴胺酸、铜粉存在下,树脂用量为16g/L,在70℃下反应3h,溴胺酸缩合产物收率可达94.0%。反应中所使用的离子交换树脂、铜粉和乙醇均可回收再利用,强酸离子交换树脂重复使用5次后其催化活性仍未降低;乙醇回收率可达70%～80%,铜粉的回收率可达85%～90%。     

叶黄素简介

叶黄素属类胡萝卜素,近年研究发现其具有保护视觉、抗氧化、抗癌等作用。本文从叶黄素的结构、性质、来源、生理功效、研究现状及应用前景等方面进行了介绍。     

纳米色料的制备及应用

纳米色料是一类可以结合颜料和染料两者优点的新型色料,除了在传统的着色领域具有独特优势外,在光电高新技术领域也具有广阔的应用前景。本文综述了国内外有机纳米色料在制备和应用上的最新研究进展,归纳出几种有代表性的制备有机纳米色料以及有机色料/无机物杂合纳米色料的最新研究方法。着重论述了细乳液聚合法制备纳米色料,对各种制备方法作出比较评价,并结合研究现状对纳米色料在光电领域的应用提出了一些设想。     

Bruch’s-Mimetic Nanofibrous Membranes Functionalized with the Integrin-Binding Peptides as a Promising Approach for Human Retinal Pigment Epithelium Cell Transplantation

Background: This study aimed to develop an ultrathin nanofibrous membrane able to, firstly, mimic the natural fibrous architecture of human Bruch’s membrane (BM) and, secondly, promote survival of retinal pigment epithelial (RPE) cells after surface functionalization of fibrous membranes. Methods: Integrin-binding peptides (IBPs) that specifically interact with appropriate adhesion receptors on RPEs were immobilized on Bruch’s-mimetic membranes to promote coverage of RPEs. Surface morphologies, Fourier-transform infrared spectroscopy spectra, contact angle analysis, Alamar Blue assay, live/dead assay, immunofluorescence staining, and scanning electron microscopy were used to evaluate the outcome. Results: Results showed that coated membranes maintained the original morphology of nanofibers. After coating with IBPs, the water contact angle of the membrane surfaces varied from 92.38 ± 0.67 degrees to 20.16 ± 0.81 degrees. RPE cells seeded on IBP-coated membranes showed the highest viability at all time points (Day 1, p < 0.05; Day 3, p < 0.01; Days 7 and 14, p < 0.001). The proliferation rate of RPE cells on uncoated poly(ε-caprolactone) (PCL) membranes was significantly lower than that of IBP-coated membranes (p < 0.001). SEM images showed a well-organized hexa/polygonal monolayer of RPE cells on IBP-coated membranes. RPE cells proliferated rapidly, contacted, and became confluent. RPE cells formed a tight adhesion with nanofibers under high-magnification SEM. Our findings confirmed that the IBP-coated PCL membrane improved the attachment, proliferation, and viability of RPE cells. In addition, in this study, we used serum-free culture for RPE cells and short IBPs without immunogenicity to prevent graft rejection and immunogenicity during transplantation. Conclusions: These results indicated that the biomimic BM-IBP-RPE nanofibrous graft might be a new, practicable approach to increase the success rate of RPE cell transplantation.