Raman Imaging: An Impending Approach Towards Cancer Diagnosis

In accordance with the recent studies, Raman spectroscopy is well experimented as a highly sensitive analytical and imaging technique in biomedical research, mainly for various disease diagnosis including cancer. In comparison with other imaging modalities, Raman spectroscopy facilitate numerous assistances owing to its low background signal, immense spatial resolution, high chemical specificity, multiplexing capability, excellent photo stability and non-invasive detection capability. In cancer diagnosis Raman imaging intervened as a promising investigative tool to provide molecular level information to differentiate the cancerous vs non-cancerous cells, tissues and even in body fluids. Anciently, spontaneous Raman scattering is very feeble due to its low signal intensity and long acquisition time but new advanced techniques like coherent Raman scattering (CRS) and surface enhanced Raman scattering (SERS) gradually superseded these issues. So, the present review focuses on the recent developments and applications of Raman spectroscopy-based imaging techniques for cancer diagnosis.     

基于模拟退火的CRS算法

本文是对非线性规划问题提出的一种算法,该算法把模拟退火算法应用到CRS算法中,根据模拟退火算法每一次迭代都体现集中和扩散两个策略的平衡的特点,使CRS算法更能够搜索到全局最优解,而不会陷入局部最优解。最后把提出的算法应用到两个典型的函数优化问题中,结果表明,算法是可行的、有效的     

Mobile-phone-based classroom response systems: Students’ perceptions of engagement and learning in a large undergraduate course

Using a Classroom Response System (CRS) has been associated with positive educational outcomes, by fostering student engagement and by allowing immediate feedback to both students and instructors. This study examined a low-cost CRS (VotApedia) in a large first-year class, where students responded to questions using their mobile phones. This study explored whether the use of VotApedia retained the advantages of other CRS, overcame some of the challenges of other CRS, and whether new challenges were introduced by using VotApedia. These issues were studied within three themes: students’ perceptions of using VotApedia; the impact of VotApedia on their engagement; and the impact of VotApedia on their learning. Data were collected from an online survey, focus groups and student feedback on teaching and course content. The results indicated that using VotApedia retains the pedagogical advantages of other CRS, while overcoming some of the challenges presented by using other CRS, without introducing any new challenges.     

Effect of spectrum processing procedure on the linearity of EPR dose reconstruction in tooth enamel

Electron Paramagnetic Resonance (EPR) spectroscopy with tooth enamel is a widely used method of dosimetry. The accuracy of EPR tooth dosimetry depends on the spectrum processing procedure, the quality of which, in its turn, relies on instrumental noise and the signals from impurities. This is especially important in low-dose evaluation. The current paper suggests a method to estimate the accuracy of a specific spectrum processing procedure. The method is based on reconstruction of the radiation-induced signal (RIS) from a simulated spectrum with known RIS intensity. The Monte Carlo method was used for the simulations. The model of impurity and noise signals represents a composite residual spectrum (CRS) obtained by subtraction of the reconstructed RIS and the native background signal (BGS) from enamel spectra measured in HMGU (Neuherberg, Germany) and IMP (Yekaterinburg, Russia). The simulated spectra were deconvoluted using a standard procedure. The method provides an opportunity to compare the simulated “true” RIS with reconstructed values. Two modifications of the EPR method were considered: namely, with and without the use of the reference Mn²⁺ signals. It was observed that the spectrum processing procedure induces a nonlinear dose response of the reconstructed EPR amplitude when the height of the true RIS is comparable with the amplitudes of noise-like random splashes of CRS. The area of nonlinearity is below the limit of detection (DL). The use of reference Mn²⁺ signals can reduce the range of nonlinearity. However, the impact of the intensities of CRS random signals on nonlinearity is two times higher than the one observed when the reference signals were not used. The reproducibility of the software response is also dependent on both the amplitude of the CRS and the use of a reference signal, and it is also two times more sensitive to the amplitude of the CRS. In most EPR studies, all of the data are used, even those for which the dose value is lower than the DL. This study shows that low doses evaluated with the help of linear dose–response can be significantly overestimated. It is recommended that linear dose response calibration curves be constructed using only data above the DL. Data below the DL should be interpreted cautiously.     

Alkali-hydrolysis of <Emphasis Type="Italic">D</Emphasis>-glucono-delta-lactone studied by chiral Raman and circular dichroism spectroscopies

The alkali-hydrolysis of D-glucono-delta-lactone (GDL) was investigated by chiral Raman and circular dichroism (CD) spectroscopies in combination with density functional theory calculation. Based on the characteristic CD bands of GDL and its hydrolysis product, the dynamics of hydrolysis was studied using stopped-flow CD method. Using chiral Raman spectroscopy (CRS), the stereochemical change of GDL owing to the hydrolysis reaction was discussed on the vibrational scale. The CRS results show that the ring-opening due to hydrolysis has a great influence on the chiral structure around the carbonyl group, which was evidenced by the disappearance of the CRS band at 1735 cm 1 (C=O stretching vibrational mode). In addition, the change of positions and intensity of CRS bands was also observed, which was ascribed to the perturbation around the C2, C3, C4 and C5 carbons due to ring-opening. It is worthy to note that the stereochemistry of C2, C3, C4 and C5 had no fundamental change during the hydrolysis reaction, which was reflected in the maintenance of the signs of the CRS bands. Our results demonstrate that in comparison with CD technique, CRS may provide more detailed structural information of chiral molecules and open up new vistas of research for chiral reactions. Supported by the National Natural Science Foundation of China (Grant Nos. 20621063, 20773123, and 20673110) and Programme for Strategic Scientific Alliances between China and the Netherlands (Grant No. 2008DFB50130) 1) In some reference, chiral Raman spectroscopy (CRS) is also called Raman optical activity (ROA).     

Polarization resolved stimulated raman scattering: probing depolarization ratios of liquids

Polarization resolved stimulated Raman scattering (SRS) signal is described in the case of isotropic media and linearly polarized incident fields. The model gives simple expressions for the two perpendicularly polarized SRS signals I_X and I_Y, detected along the X and Y directions, respectively, as a function of the incident pump and Stokes polarization angles. We find that Raman depolarization ratio can be simply obtained from the ratio of the SRS intensities detected along the X and Y axis. These theoretical findings are supported by polarization resolved SRS measurements performed on polarized and depolarized bands of cyclohexane. Copyright © 2011 John Wiley & Sons, Ltd.     

Separation of somatropin charge variants by multiple‐injection CZE with Polybrene/chondroitin sulfate A double‐coated capillaries

The performance of dynamic double‐coated fused‐silica capillaries with Polybrene and chondroitin sulfate A has been compared with uncoated fused‐silica capillaries for the determination of recombinant human growth factor (somatropin) charge variants. The separations were carried out under the same electrophoretic conditions as described in the European Pharmacopoeia, i.e. at pH 6.0 and 30°C. The coating significantly reduced the interactions between the proteins and the surface of the fused‐silica capillary. The first five separations performed in a new bare fused‐silica capillary were discarded because of very poor separation performance as a result of protein–surface interactions. There was an approximate twofold increase in the interday migration time precision (%RSD ≤ 6.5%) in the double‐coated capillaries. The method was successfully transferred to a multiple CZE mode where two samples were analyzed in a single electrophoretic run. The average purity of somatropin certified reference standard was 98.0% (%RSD ≤ 0.3%) determined by using uncoated and coated capillaries.     

基于岭回归分析法的太湖CRS紫外光谱回归模型

分析了太湖36个采用点水样铬还原性硫（Chromium reducible sulfur,CRS）与可溶性有机碳DOC以及5个波长吸光度之间的关系,发现CRS与DOC并不存在回归关系。但陆源水样CRS与DOC以及吸光度均有较好的相关性。在建立CRS紫外光谱多元回归模型的过程中,为了解决吸光度共线性的影响,采用岭回归法构建多元回归模型。通过两种途径建立回归方程,一是将各波长吸光度分别与CRS建立的一元线性回归方程作为子模型,再按岭回归方法将子模型构建成组合模型;二是直接采用岭回归法建立吸光度与CRS的多元回归模型。两模型在反映CRS与紫外光谱的回归关系上具有一致性。     

Solving the Generalized Higgs Model from the Generalized CRS Model

In this paper,we reveal a direct relation between the generalized one-dimensional Carinena-RanadaSantander(CRS) model and the radial part of two-dimensional generalized Higgs model.By this relation,we construct a series of quasi-exactly solutions for the two-dimensional Higgs model from a solved generalized CRS model.