Label-Free Characterization of Macrophage Polarization Using Raman Spectroscopy

Macrophages are important cells of the innate immune system that play many different roles in host defense, a fact that is reflected by their polarization into many distinct subtypes. Depending on their function and phenotype, macrophages can be grossly classified into classically activated macrophages (pro-inflammatory M1 cells), alternatively activated macrophages (anti-inflammatory M2 cells), and non-activated cells (resting M0 cells). A fast, label-free and non-destructive characterization of macrophage phenotypes could be of importance for studying the contribution of the various subtypes to numerous pathologies. In this work, single cell Raman spectroscopic imaging was applied to visualize the characteristic phenotype as well as to discriminate between different human macrophage phenotypes without any label and in a non-destructive manner. Macrophages were derived by differentiation of peripheral blood monocytes of human healthy donors and differently treated to yield M0, M1 and M2 phenotypes, as confirmed by marker analysis using flow cytometry and fluorescence imaging. Raman images of chemically fixed cells of those three macrophage phenotypes were processed using chemometric methods of unmixing (N-FINDR) and discrimination (PCA-LDA). The discrimination models were validated using leave-one donor-out cross-validation. The results show that Raman imaging is able to discriminate between pro- and anti-inflammatory macrophage phenotypes with high accuracy in a non-invasive, non-destructive and label-free manner. The spectral differences observed can be explained by the biochemical characteristics of the different phenotypes.     

IR spectroscopy as a quantitative and predictive analysis method of phenol–formaldehyde resol resins

A set of resin samples was characterized by IR and ¹³C-NMR spectroscopy. The suitability of IR spectroscopy for the quantitative analysis of resins was evaluated by statistical methods using the NMR reference data as calibration. The values of interesting properties, for example, the amount of free phenol and the formaldehyde-to-phenol (F/P) molar ratio, of the resins being similar to the calibration resins were predicted from the IR spectra. Also, the predicted results were compared with the ones observed by ¹³C-NMR spectroscopy. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2175–2185, 1998     

Ellipsometric spectroscopy study of cobalt oxide thin films deposited by sol–gel

Due to their unique optical properties, solar selective coatings enhance the thermal efficiency of solar photothermal converters. Hence it seems to be interesting to study the optical properties of promising materials as solar selective coatings. In an earlier work, it was demonstrated that sol–gel deposited cobalt oxide thin films possess suitable optical properties as selective coatings. In this work, cobalt oxide thin films were prepared by same technique and their optical properties were analyzed as a function of the dipping time of the substrate in the sol, using the spectroscopy ellipsometry, atomic force microscopy and X-ray photoelectron spectroscopy techniques. The optical constants (n and k) for these films, in the 200–800 nm range, are reported as a function of the dipping time. The fitting of ellipsometric data, I_s and I_c, for the glass substrate and the cobalt oxide thin film, as modeled with the Lorentz and Tauc–Lorentz dispersion relations, indicated that the film microstructure resembles a multilayer stack with voids. From these results, the Co₃O₄ and void percentages in the film were estimated. Both, thin film thickness and void/Co₃O₄ percentage ratio, were determined to be strongly dependent on the immersion time. Furthermore, the total thickness of a multilayered film was found to be the sum of thickness of each individual layer.     

Transport of matter upon annealing in crystalline polymethylene systems: a calorimetric and spectroscopic study

Following Ungar and Keller we have shown that when a mechanical mixture of two solid and crystalline n-alkanes of slightly different length is annealed at temperatures below the melting point of the shorter compound a mixed crystal is obtained. Calorimetric and spectroscopic studies indicate that n-alkane chains of one molecular species are able to move out of the crystallite and diffuse into the crystal of the other species. A detailed mechanism on a molecular level consistent with calorimetric and spectroscopic experiments is proposed. Molecules migrate substantially as rigid bodies with no distinct sharp conformational distortions. The same phenomenon is observed for a mechanical mixture of C₃₆H₇₄ and for its perdeutero-derivative of the same length. The conclusions of Ungar and Keller are substantiated and new structural details are presented.     

桑葚酒中花青素含量的测定方法优化

为确定pH示差法测定桑葚酒中花青素的最佳测定条件,本文对pH示差法测定桑葚酒中花青素含量的最佳测定波长、缓冲液的最适pH、平衡温度和时间等条件进行优化,并且对优化的pH示差法进行方法学评价。结果表明,在波长519 nm、缓冲液pH为1.0和4.5、于30 ℃下恒温40 min后测定桑葚酒中花青素含量是最佳的条件。测定桑葚酒中花青素的含量为23.80 mg/L。该方法的相对标准偏差(RSD)为2.076%,加标回收率为99.59%~102.70%,说明用优化后的pH示差法测定桑葚酒中花青素含量是准确可靠的。本文为酒为存在介质的花青素定量分析提供了借鉴。     

从天然产物创制新药的发展趋势

文章展望了从天然产物中创制新药的发展趋势。单味中草药有效成分的研究重点将转向瞄准质控的中药复方化学成分研究。进入21世纪,中国天然药物研究要在国际上占有重要位置,突破口便是中药复方现代化,其关键之一便是化学（有效）成分研究。从中草药中发现有效成分或先导物必须采用化学成分与生物活性研究融为一体的机制,采用高通量筛选,目标就是寻找有效成分或先导物进而创制新药。长短结合,正确处理知识创新和新药开发的关系。知识创新须体现在创制新药的应用基础研究中,是产生巨大效益的理论基础;短程开发是知识累积水平的体现,是科研经费的必要补充和保证。改革传统天然产物化学研究模式,实施以当代最先进大型谱仪为先导的天然产物研究战略。     

Stereoscopic representation of complex overlapping elemental maps in electron spectroscopic images

A stereoscopic method is described enabling the direct visualization of the spatial relationships of elemental maps generated by electron spectroscopic imaging. The cartilage growth plate in early stages of mineralization was used to illustrate elemental maps of calcium, phosphorus, and sulphur. Stereopsis is achieved by creating a stereo-pair which in one image of the pair the elemental maps are superpositioned as they occur naturally while in the second image the maps are laterally shifted. In a stereo perspective the maps appear superpositioned in distinct planes.     

气体光谱数据库对气体辐射特性的影响

利用最新光谱数据库提出了基于数据库的普朗克平均吸收系数计算方法和逐线法,并针对一维平行平板间等温辐射传热问题探讨了逐线法(line-by-line,LBL)、统计窄谱带模型(statistical narrow-band model,SNB)和统计窄谱带关联K模型(statistical narrow-band correlated-K model,SNBCK)计算原理、计算精度和三模型间的偏离变化。结果表明,三种模型的结果吻合较好,几个数据库都比较准确。对于逐线法,表明可采用HITRAN2012(high resolution TRANsmission spectroscopic database)光谱数据库替代HITEMP2010(high-TEMPerature spectroscopic absorption parameters spectroscopic database)数据库来提高计算效率。     

X荧光能谱技术鉴别淡水珍珠和海水珍珠的应用

采用X荧光能谱技术研究珍珠中微量元素的种类及其质量分数,以达到无损鉴别淡水珍珠和海水珍珠的目的。利用X射线荧光能谱仪优选适合的激发工作条件,通过设定相同的工作条件,获得珍珠主量元素和微量元素的能量色散图谱,定性分析其主量元素和微量元素的组合关系。其中,Mn的特征峰与Sr/Ca计数比率对鉴别珍珠品种有重要的指示意义。研究表明,在电压为30～35kV、电流为0.50～0.80mA、滤光片PdThick的测试条件下,淡水珍珠一般具有Ca+Sr+Mn的组合关系,海水珍珠具有Ca+Sr的组合关系;淡水珍珠中的Sr/Ca介于0.14～0.37,海水珍珠中的Sr/Ca介于0.46～0.71。综合利用元素的组合关系和Sr/Ca计数比率,可快捷、无损地鉴别珍珠品种。     

曼陀罗种子中总黄酮含量测定及提取工艺的研究

采用乙醇浸提法提取山楂中的黄酮类化合物.结果表明:浸提的最佳条件是:70ml 95%乙醇在60℃下浸提1h.本实验采用分光光度法,以芦丁为标准样品测定山楂曼陀罗种子中总黄酮的含量,总黄酮含量为4.016%.方法简便、快速、重现性好,可作为检测曼陀罗中黄酮含量的一种手段.