Journal of Spectroscopy The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Chemistry and Bioactivity of NeoMTA Plus™ versus MTA Angelus® Root Repair Materials Sun, 08 Oct 2017 00:00:00 +0000 Objectives. To analyse the chemistry and bioactivity of NeoMTA Plus in comparison with the conventional root repair materials. Method and Materials. Unhydrated and hydrated (initial and final sets) materials were analysed by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). For bioactivity study, small holes of dentin discs were filled with either materials, immersed in PBS for 15 days, and analysed with FTIR and scanning electron microscope with energy dispersive X-ray (SEM/EDX). The calculation of crystallinity and carbonate/phosphate (CO3/PO4) ratio of surface precipitates (from FTIR) and calcium/phosphate (Ca/P) ratio (from EDX) was statistically analysed using t-test or ANOVA, respectively, at 0.05 significance. Results. Both materials are tricalcium silicate-based that finally react to be calcium silicate hydrate. NeoMTA Plus has relatively high aluminium and sulfur content, with tantalum oxide as an opacifier instead of zirconium oxide in MTA Angelus. NeoMTA Plus showed better apatite formation, higher crystallinity and Ca/P but lower CO3/PO4 ratio than MTA Angelus. SEM showed globular structure with a small particle size in NeoMTA Plus while spherical structure with large particle size in MTA Angelus. Conclusion. Due to fast setting, higher crystallinity, and better bioactivity of NeoMTA Plus, it can be used as a pulp and root repair material. Sawsan T. Abu Zeid, Najlaa M. Alamoudi, Monazah G. Khafagi, and Ensanya A. Abou Neel Copyright © 2017 Sawsan T. Abu Zeid et al. All rights reserved. Photo-Induced Cell Damage Analysis for Single- and Multifocus Coherent Anti-Stokes Raman Scattering Microscopy Sun, 01 Oct 2017 00:00:00 +0000 In this study, we investigated photo-induced damage to living cells during single- and multifocus excitations for coherent anti-Stokes Raman scattering (CARS) imaging. A near-infrared pulsed laser (709 nm) was used to induce cell damage. We compared the photo-induced cell damage in the single- and the multifocus excitation schemes with the condition to obtain the same CARS signal in the same frame rate. For the evaluation of cell viability, we employed 4,6-diamidino-2-phenylindole (DAPI) fluorophores that predominantly stained the damaged cells. One- and two-photon fluorescence of DAPI fluorophores were, respectively, excited by an ultraviolet light source and the same near-infrared light source and were monitored to evaluate the cell viability during near-infrared pulsed laser irradiation. We found lower uptake of DAPI fluorophores into HeLa cells during the multifocus excitation compared with the single-focus excitation scheme in both the one- and the two-photon fluorescence examinations. This indicates a reduction of photo-induced cell damage in the multifocus excitation. Our findings suggested that the multifocus excitation scheme is expected to be suitable for CARS microscopy in terms of minimal invasiveness. Takeo Minamikawa, Yoshinori Murakami, Naokazu Matsumura, Hirohiko Niioka, Shuichiro Fukushima, Tsutomu Araki, and Mamoru Hashimoto Copyright © 2017 Takeo Minamikawa et al. All rights reserved. A Comprehensive Study on Gamma Rays and Fast Neutron Sensing Properties of GAGOC and CMO Scintillators for Shielding Radiation Applications Tue, 26 Sep 2017 07:16:43 +0000 The WinXCom program has been used to calculate the mass attenuation coefficients (μm), effective atomic numbers (Zeff), effective electron densities (Nel), half-value layer (HVL), and mean free path (MFP) in the energy range 1 keV–100 GeV for Gd3Al2Ga3O12Ce (GAGOC) and CaMoO4 (CMO) scintillator materials. The geometrical progression (G-P) method has been used to compute the exposure buildup factors (EBF) and gamma ray energy absorption (EABF) in the photon energy range 0.015–15 MeV and up to a 40 penetration depth (mfp). In addition, the values of the removal cross section for a fast neutron have been calculated. The computed data observes that GAGOC showed excellent γ-rays and neutrons sensing a response in the broad energy range. This work could be useful for nuclear radiation sensors, detectors, nuclear medicine applications (medical imaging and mammography), nuclear engineering, and space technology. Shams A. M. Issa, M. I. Sayyed, M. H. M. Zaid, and K. A. Matori Copyright © 2017 Shams A. M. Issa et al. All rights reserved. Quantitative Analysis and Comparison of Flavonoids in Lotus Plumules of Four Representative Lotus Cultivars Tue, 26 Sep 2017 00:00:00 +0000 The flavonoids in lotus plumules from four representative lotus cultivars have been analyzed using high-performance liquid chromatography coupled with ultraviolet detector and electrospray ionization triple quadrupole mass spectrometry. By this means, sixteen flavonoids were successfully measured and compared among four cultivars. Although similar flavonoid compositions were detected from these four cultivars, their flavonoid contents were significantly different. cv. Bailian from Guangchang was detected to have the most total flavonoid content, that is, 1595.86 mg/100 g, followed by cv. Xuanlian from Wuyi (1553.49 mg/100 g), cv. Xianglian from Xiangtan (1173.07 mg/100 g), and cv. Jianlian from Jianning (930.08 mg/100 g). However, similar percentages of flavonoid C-glycosides in the total flavonoids were found for four cultivars, which were 80.83% for cv. Bailian, 80.91% for cv. Xianglian, 79.25% for cv. Jianlian, and 78.53% for cv. Xuanlian. This work will be very useful for quality assurance and control for the lotus plumules from different origins in terms of qualitative and quantitative information about flavonoids. It will also be of special interest in the screening of lotus plumules with high flavonoid content, which are preferred due to their wide potential applications in food and pharmaceutical industries. Ting Liu, Mingzhi Zhu, Chunyun Zhang, and Mingquan Guo Copyright © 2017 Ting Liu et al. All rights reserved. Rancidity Estimation of Perilla Seed Oil by Using Near-Infrared Spectroscopy and Multivariate Analysis Techniques Sun, 17 Sep 2017 08:39:20 +0000 Near-infrared spectroscopy and multivariate analysis techniques were employed to nondestructively evaluate the rancidity of perilla seed oil by developing prediction models for the acid and peroxide values. The acid, peroxide value, and transmittance spectra of perilla seed oil stored in two different environments for 96 and 144 h were obtained and used to develop prediction models for different storage conditions and time periods. Preprocessing methods were applied to the transmittance spectra of perilla seed oil, and multivariate analysis techniques, such as principal component regression (PCR), partial least squares regression (PLSR), and artificial neural network (ANN) modeling, were employed to develop the models. Titration analysis shows that the free fatty acids in an oil oxidation process were more affected by relative humidity than temperature, whereas peroxides in an oil oxidation process were more significantly affected by temperature than relative humidity for the two different environments in this study. Also, the prediction results of ANN models for both acid and peroxide values were the highest among the developed models. These results suggest that the proposed near-infrared spectroscopy technique with multivariate analysis can be used for the nondestructive evaluation of the rancidity of perilla seed oil, especially the acid and peroxide values. Suk-Ju Hong, Shin-Joung Rho, Ah-Yeong Lee, Heesoo Park, Jinshi Cui, Jongmin Park, Soon-Jung Hong, Yong-Ro Kim, and Ghiseok Kim Copyright © 2017 Suk-Ju Hong et al. All rights reserved. A Feasibility Study on the Potential Use of Near Infrared Reflectance Spectroscopy to Analyze Meat in Live Animals: Discrimination of Muscles Thu, 14 Sep 2017 00:00:00 +0000 Near infrared (NIR) spectroscopy has been proposed as a potential method to analyze different properties in live animals and humans, as infrared light has the ability to penetrate living tissues. This study evaluated the potential use of NIR spectroscopy to identify and analyze beef muscles through the skin nondestructively. The results from this study demonstrated that the NIR region has the potential to noninvasively monitor some properties of meat associated with either fat or muscle characteristics and to differentiate either muscle or fat tissue analyzed through the skin. At present, there are no rapid and noninvasive tools to monitor and assess any characteristic or property in live beef animals. Although these results look promising, more experiments and research need to be carried out before recommending the beef industry using this technology in live animals. J. J. Roberts, J. Ch. Motin, D. Swain, and D. Cozzolino Copyright © 2017 J. J. Roberts et al. All rights reserved. Electronic Controlling on Nanotribological Properties of a Textured Surface by Laser Processing Wed, 06 Sep 2017 00:00:00 +0000 The friction-reducing performance of surfaces with regular nanotextures is a key topic in surface engineering research. This paper presented a simple, easily controlled method for fabricating regular nanotextures on an electrodeposited Ni-Co alloy. The electronic controlling on the friction performance of a nanotexured surface was investigated by AFM. The results showed that the frictional force of a nanotexured surface can be controlled by an external electric field. Before laser processing, the friction initially increased with the bias voltage and then decreased after the bias voltage exceeded 1.0 V. Its friction forces can be changed more than 2 times under the different external electric field. After laser processing, the trend of the frictional force was reversed and its friction forces changed more than 12 times for the laser-processed sample with 0.18 J/cm2 laser power. The results also showed that the friction force decreased when using different nanotextures in an external electric field. Haifeng Yang, Kun Liu, Yanqing Wang, Hao Liu, Jiaxiang Man, and Bo Sun Copyright © 2017 Haifeng Yang et al. All rights reserved. Feasibility of Terahertz Time-Domain Spectroscopy to Detect Carbendazim Mixtures Wrapped in Paper Wed, 09 Aug 2017 05:41:57 +0000 The purpose of this work was to detect carbendazim mixtures wrapped in paper. Unlike previous reports of THz-TDS for detecting pesticide residue, this work focused on detecting pesticide residue in packaged foods. Different weight ratios of carbendazim in polyethylene and in rice powder were detected qualitatively and quantitatively. Results show that pure carbendazim, polyethylene, and rice powder can be easily distinguished from each other. However, when the weight ratio was low, the absorbance of the mixture was similar with that of pure polyethylene and rice powder. With the help of SVM, carbendazim could be qualitatively detected in low weight ratio mixture successfully. Moreover, PLS and SVR were selected to quantitatively detect carbendazim mixtures. SVR has higher R and lower RMSECV, RMSEC, and RMSEP than PLS model. Lasty, the results also indicate that THz-TDS is a potential tool to detect pesticide residue in packaged foods qualitatively and quantitatively. Binyi Qin, Zhi Li, Zhihui Luo, Huo Zhang, and Yun Li Copyright © 2017 Binyi Qin et al. All rights reserved. Application of Permutation Entropy in Feature Extraction for Near-Infrared Spectroscopy Noninvasive Blood Glucose Detection Wed, 09 Aug 2017 02:21:57 +0000 Diabetes has been one of the four major diseases threatening human life. Accurate blood glucose detection became an important part in controlling the state of diabetes patients. Excellent linear correlation existed between blood glucose concentration and near-infrared spectral absorption. A new feature extraction method based on permutation entropy is proposed to solve the noise and information redundancy in near-infrared spectral noninvasive blood glucose measurement, which affects the accuracy of the calibration model. With the near-infrared spectral data of glucose solution as the research object, the concepts of approximate entropy, sample entropy, fuzzy entropy, and permutation entropy are introduced. The spectra are then segmented, and the characteristic wave bands with abundant glucose information are selected in terms of permutation entropy, fractal dimension, and mutual information. Finally, the support vector regression and partial least square regression are used to establish the mathematical model between the characteristic spectral data and glucose concentration, and the results are compared with conventional feature extraction methods. Results show that the proposed new method can extract useful information from near-infrared spectra, effectively solve the problem of characteristic wave band extraction, and improve the analytical accuracy of spectral and model stability. Xiaoli Li and Chengwei Li Copyright © 2017 Xiaoli Li and Chengwei Li. All rights reserved. Measurement of the Euler Angles of Wurtzitic ZnO by Raman Spectroscopy Tue, 08 Aug 2017 07:46:40 +0000 A Raman spectroscopy-based step-by-step measuring method of Euler angles was presented for the wurtzitic crystal orientation on a microscopic scale. Based on the polarization selection rule and coordinate transformation theory, a series of analytic expressions for the Euler angle measurement using Raman spectroscopy were derived. Specific experimental measurement processes were presented, and the measurement of Raman tensor elements and Euler angles of the ZnO crystal were implemented. It is deduced that there is a trigonometric functional relationship between the intensity of each Raman bands of wurtzite crystal and Euler angle , the polarization direction of incident light under different polarization configurations, which can be used to measure the Euler angles. The experimental results show that the proposed method can realize the measurement of Euler angles for wurtzite crystal effectively. Wu Liu, Qiu Li, Gang Jin, and Wei Qiu Copyright © 2017 Wu Liu et al. All rights reserved. Application of Near-Infrared Spectroscopy to Quantitatively Determine Relative Content of Puccnia striiformis f. sp. tritici DNA in Wheat Leaves in Incubation Period Sun, 06 Aug 2017 00:00:00 +0000 Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a devastating wheat disease worldwide. Potential application of near-infrared spectroscopy (NIRS) in detection of pathogen amounts in latently Pst-infected wheat leaves was investigated for disease prediction and control. A total of 300 near-infrared spectra were acquired from the Pst-infected leaf samples in an incubation period, and relative contents of Pst DNA in the samples were obtained using duplex TaqMan real-time PCR arrays. Determination models of the relative contents of Pst DNA in the samples were built using quantitative partial least squares (QPLS), support vector regression (SVR), and a method integrated with QPLS and SVR. The results showed that the kQPLS-SVR model built with a ratio of training set to testing set equal to 3 : 1 based on the original spectra, when the number of the randomly selected wavelength points was 700, the number of principal components was 8, and the number of the built QPLS models was 5, was the best. The results indicated that quantitative detection of Pst DNA in leaves in the incubation period could be implemented using NIRS. A novel method for determination of latent infection levels of Pst and early detection of stripe rust was provided. Yaqiong Zhao, Yilin Gu, Feng Qin, Xiaolong Li, Zhanhong Ma, Longlian Zhao, Junhui Li, Pei Cheng, Yang Pan, and Haiguang Wang Copyright © 2017 Yaqiong Zhao et al. All rights reserved. Selective Surface Sintering Using a Laser-Induced Breakdown Spectroscopy System Thu, 27 Jul 2017 00:00:00 +0000 Titanium metal injection molding allows creation of complex metal parts that are lightweight and biocompatible with reduced cost in comparison with machining titanium. Laser-induced breakdown spectroscopy (LIBS) can be used to create plasma on the surface of a sample to analyze its elemental composition. Repetitive ablation on the same site has been shown to create differences from the original sample. This study investigates the potential of LIBS for selective surface sintering of injection-molded titanium metal. The temperature created throughout the LIBS process on the surface of the injection-molded titanium is high enough to fuse together the titanium particles. Using the ratio of the Ti II 282.81 nm and the C I 247.86 nm lines, the effectiveness of repetitive plasma formation to produce sintering can be monitored during the process. Energy-dispersive X-ray spectroscopy on the ablation craters confirms sintering through the reduction in carbon from 20.29 Wt.% to 2.13 Wt.%. Scanning electron microscope images confirm sintering. A conventional LIBS system, with a fixed distance, investigated laser parameters on injection-molded and injection-sintered titanium. To prove the feasibility of using this technique on a production line, a second LIBS system, with an autofocus and 3-axis translation stage, successfully sintered a sample with a nonplanar surface. H. Jull, P. Ewart, R. Künnemeyer, and P. Schaare Copyright © 2017 H. Jull et al. All rights reserved. Longitudinal Raman Spectroscopic Observation of Skin Biochemical Changes due to Chemotherapeutic Treatment for Breast Cancer in Small Animal Model Sun, 16 Jul 2017 00:00:00 +0000 The cancer field effect (CFE) has been highlighted as one of indirect indications for tissue variations that are insensitive to conventional diagnostic techniques. In this research, we had a hypothesis that chemotherapy for breast cancer would affect skin biochemical compositions that would be reflected by Raman spectral changes. We used a fiber-optic probe-based Raman spectroscopy to perform preliminary animal experiments to validate the hypothesis. Firstly, we verified the probing depth of the fiber-optic probe (~800 μm) using a simple intravenous fat emulsion-filled phantom having a silicon wafer at the bottom inside a cuvette. Then, we obtained Raman spectra during breast cancer treatment by chemotherapy from a small animal model in longitudinal manner. Our results showed that the treatment causes variations of biochemical compositions in the skin. For further validation, the Raman spectra will have to be collected from more populations and spectra will need to be compared with immunohistochemistry of the breast tissue. Myeongsu Seong, NoSoung Myoung, Songhyun Lee, Hyeryun Jeong, Sang-Youp Yim, and Jae Gwan Kim Copyright © 2017 Myeongsu Seong et al. All rights reserved. Raman Spectroscopic Study of As-Deposited and Exfoliated Defected Graphene Grown on (001) Si Substrates by CVD Tue, 27 Jun 2017 00:00:00 +0000 We present here results on a Raman spectroscopic study of the deposited defected graphene on Si substrates by chemical vapor deposition (thermal decomposition of acetone). The graphene films are not deposited on the (001) Si substrate directly but on two types of interlayers of mixed phases unintentionally deposited on the substrates: а diamond-like carbon (designated here as DLC) and amorphous carbon (designated here as αC) are dominated ones. The performed thorough Raman spectroscopic study of as-deposited as well as exfoliated specimens by two different techniques using different excitation wavelengths (488, 514, and 613 nm) as well as polarized Raman spectroscopy establishes that the composition of the designated DLC layers varies with depth: the initial layers on the Si substrate consist of DLC, nanodiamond species, and C70 fullerenes while the upper ones are dominated by DLC with an occasional presence of C70 fullerenes. The αC interlayer is dominated by turbostratic graphite and contains a larger quantity of C70 than the DLC-designated interlayers. The results of polarized and unpolarized Raman spectroscopic studies of as-grown and exfoliated graphene films tend to assume that single- to three-layered defected graphene is deposited on the interlayers. It can be concluded that the observed slight upshift of the 2D band as well as the broadening of 2D band should be related to the strain and doping. T. I. Milenov, E. Valcheva, and V. N. Popov Copyright © 2017 T. I. Milenov et al. All rights reserved. Quantitative Estimation of Organic Matter Content in Arid Soil Using Vis-NIR Spectroscopy Preprocessed by Fractional Derivative Tue, 13 Jun 2017 00:00:00 +0000 Soil organic matter (SOM) content is an important index to measure the level of soil function and soil quality. However, conventional studies on estimation of SOM content concerned about the classic integer derivative of spectral data, while the fractional derivative information was ignored. In this research, a total of 103 soil samples were collected in the Ebinur Lake basin, Xinjiang Uighur Autonomous Region, China. After measuring the Vis-NIR (visible and near-infrared) spectroscopy and SOM content indoor, the raw reflectance and absorbance were treated by fractional derivative from 0 to 2nd order (order interval 0.2). Partial least squares regression (PLSR) was applied for model calibration, and five commonly used precision indices were used to assess the performance of these 22 models. The results showed that with the rise of order, these parameters showed the increasing or decreasing trends with vibration and reached the optimal values at the fractional order. A most robust model was calibrated based on 1.8 order derivative of R, with the lowest RMSEC (3.35 g kg−1) and RMSEP (2.70 g kg−1) and highest (0.92), (0.91), and RPD (3.42 > 3.0). This model had excellent predictive performance of estimating SOM content in the study area. Jingzhe Wang, Tashpolat Tiyip, Jianli Ding, Dong Zhang, Wei Liu, and Fei Wang Copyright © 2017 Jingzhe Wang et al. All rights reserved. Study on the Noise Reduction of Vehicle Exhaust NOX Spectra Based on Adaptive EEMD Algorithm Mon, 12 Jun 2017 09:16:15 +0000 It becomes a key technology to measure the concentration of the vehicle exhaust components with the transmission spectra. But in the conventional methods for noise reduction and baseline correction, such as wavelet transform, derivative, interpolation, polynomial fitting, and so forth, the basic functions of these algorithms, the number of decomposition layers, and the way to reconstruct the signal have to be adjusted according to the characteristics of different components in the transmission spectra. The parameter settings of the algorithms above are not transcendental, so with them, it is difficult to achieve the best noise reduction effect for the vehicle exhaust spectra which are sharp and drastic in the waveform. In this paper, an adaptive ensemble empirical mode decomposition (EEMD) denoising model based on a special normalized index optimization is proposed and used in the spectral noise reduction of vehicle exhaust NOX. It is shown with the experimental results that the method can effectively improve the accuracy of the spectral noise reduction and simplify the denoising process and its operation difficulty. Kai Zhang, Yujun Zhang, Kun You, Ying He, Qiankun Gao, Guohua Liu, Chungui He, Yibing Lu, Boqiang Fan, Qixing Tang, and Wenqing Liu Copyright © 2017 Kai Zhang et al. All rights reserved. Detection of Water Contamination Events Using Fluorescence Spectroscopy and Alternating Trilinear Decomposition Algorithm Tue, 30 May 2017 00:00:00 +0000 The method based on conventional index and UV-vision has been widely applied in the field of water quality abnormality detection. This paper presents a qualitative analysis approach to detect the water contamination events with unknown pollutants. Fluorescence spectra were used as water quality monitoring tools, and the detection method of unknown contaminants in water based on alternating trilinear decomposition (ATLD) is proposed to analyze the excitation and emission spectra of the samples. The Delaunay triangulation interpolation method was used to make the pretreatment of three-dimensional fluorescence spectra data, in order to estimate the effect of Rayleigh and Raman scattering; ATLD model was applied to establish the model of normal water sample, and the residual matrix was obtained by subtracting the measured matrix from the model matrix; the residual sum of squares obtained from the residual matrix and threshold was used to make qualitative discrimination of test samples and distinguish drinking water samples and organic pollutant samples. The results of the study indicate that ATLD modeling with three-dimensional fluorescence spectra can provide a tool for detecting unknown organic pollutants in water qualitatively. The method based on fluorescence spectra can be complementary to the method based on conventional index and UV-vision. Jie Yu, Xiaoyan Zhang, Dibo Hou, Fang Chen, Tingting Mao, Pingjie Huang, and Guangxin Zhang Copyright © 2017 Jie Yu et al. All rights reserved. Simultaneous Quantification of Paracetamol and Caffeine in Powder Blends for Tableting by NIR-Chemometry Sun, 28 May 2017 00:00:00 +0000 Near-infrared spectroscopy (NIRS) is a technique widely used for rapid and nondestructive analysis of solid samples. A method for simultaneous analysis of the two components of paracetamol and caffeine from powder blends has been developed by using chemometry with near-infrared spectroscopy (NIRS). The method development was performed on samples containing 80, 90, 100, 110, and 120% active pharmaceutical ingredients, and near-infrared spectroscopy (NIRS) spectra of prepared powder blends were recorded and analyzed in order to develop models for the prediction of drug content. Many calibration models were applied in order to perform quantitative determination of drug content in powder, and choosing the appropriate number of factors (principal components) proved to be of highly importance for a PLS chemometric calibration. Once the methods were developed, they were validated in terms of trueness, precision, and accuracy. The results obtained by NIRS methods were compared with those obtained by HPLC reference method, and no significant differences were found. Therefore, the NIR chemometry methods were proved to be a suitable tool for predicting chemical properties of powder blends and for simultaneous determination of active pharmaceutical ingredients. Dana Maria Muntean, Cristian Alecu, and Ioan Tomuta Copyright © 2017 Dana Maria Muntean et al. All rights reserved. Corrigendum to “Investigating the Degradability of HDPE, LDPE, PE-BIO, and PE-OXO Films under UV-B Radiation” Tue, 16 May 2017 00:00:00 +0000 A. Martínez-Romo, R. González-Mota, J. J. Soto-Bernal, and I. Rosales-Candelas Copyright © 2017 A. Martínez-Romo et al. All rights reserved. The Clinical Application of Raman Spectroscopy for Breast Cancer Detection Mon, 15 May 2017 00:00:00 +0000 Raman spectroscopy has been widely used as an important clinical tool for real-time in vivo cancer diagnosis. Raman information can be obtained from whole organisms and tissues, at the cellular level and at the biomolecular level. The aim of this paper is to review the newest developments of Raman spectroscopy in the field of breast cancer diagnosis and treatment. Raman spectroscopy can distinguish malignant tissues from noncancerous/normal tissues and can assess tumor margins or sentinel lymph nodes during an operation. At the cellular level, Raman spectra can be used to monitor the intracellular processes occurring in blood circulation. At the biomolecular level, surface-enhanced Raman spectroscopy techniques may help detect the biomarker on the tumor surface as well as evaluate the efficacy of anticancer drugs. Furthermore, Raman images reveal an inhomogeneous distribution of different compounds, especially proteins, lipids, microcalcifications, and their metabolic products, in cancerous breast tissues. Information about these compounds may further our understanding of the mechanisms of breast cancer. Pin Gao, Bing Han, Ye Du, Gang Zhao, Zhigang Yu, Weiqing Xu, Chao Zheng, and Zhimin Fan Copyright © 2017 Pin Gao et al. All rights reserved. Influence of Fractional Differential on Correlation Coefficient between EC1:5 and Reflectance Spectra of Saline Soil Tue, 09 May 2017 00:00:00 +0000 Soil salinization is one of the most serious environmental issues in arid and semiarid area with severe social, economic, and ecological problems. At present, most inversion models are based on raw reflectance spectra or integer differential transform. In this study, we measured the hyperspectral reflectance and EC1:5 of soil samples collected form Ebinur Lake to analyze the influence of fractional differential on correlation coefficient between EC1:5 and reflectance spectra. The results showed that the fractional differential increased sensibly the accuracy for the analysis of the reflectance spectra. The study might provide a new insight for monitoring soil salinity using hyperspectral data, and further researches should be concentrated on physical meaning of fractional differential in hyperspectral data to provide theoretical basis to building, describing, and spreading inversion models. Nan Xia, Tashpolat Tiyip, Ardak Kelimu, Ilyas Nurmemet, Jianli Ding, Fei Zhang, and Dong Zhang Copyright © 2017 Nan Xia et al. All rights reserved. Simultaneous Determination of Four Compounds in a Nelumbo nucifera Seed Embryo by HPLC-DAD Thu, 13 Apr 2017 09:50:40 +0000 Nelumbo nucifera has a variety of biological activities. So it was importantly used as various herbal medicines since traditional times. A simple, fast, and sensitive high-performance liquid chromatographic (HPLC) method was developed in this study for efficient quality control of N. nucifera. Four different compounds, including neferine, 1,2,3,4-tetrahydro-1-[(4-hydroxyphenyl) methyl]-2-methyl-7-isoquinolinol, 1-hydroxy-2-methylpropene, and 3-(prop-1-enyl)benzene-1,2,4,5-tetrol, were simultaneously determined. The four compounds were isolated through a Dionex C18 column by gradient elution with 0.1% TFA-water and methanol. The flow rate was 1.0 mL/min, and the wavelength was detected at 205, 254, 280, and 330 nm. The chromatograms were acquired at 205 nm. The four compounds showed good linear relationships () over five different concentrations, and an average recovery of the method ranged from 96.27% to 108.78%. Through the analysis validation test and application of the method, the optimized conditions verified that it is efficient to isolate the compounds of N. nucifera seed embryos. Gahee Ryu, Jin Bae Weon, Woo Seung Yang, and Choong Je Ma Copyright © 2017 Gahee Ryu et al. All rights reserved. Ultrafast Charge and Triplet State Formation in Diketopyrrolopyrrole Low Band Gap Polymer/Fullerene Blends: Influence of Nanoscale Morphology of Organic Photovoltaic Materials on Charge Recombination to the Triplet State Thu, 13 Apr 2017 00:00:00 +0000 Femtosecond transient absorption spectroscopy of thin films of two types of morphologies of diketopyrrolopyrrole low band gap polymer/fullerene-adduct blends is presented and indicates triplet state formation by charge recombination, an important loss channel in organic photovoltaic materials. At low laser fluence (approaching solar intensity) charge formation characterized by a 1350 nm band (in ~250 fs) dominates in the two PDPP-PCBM blends with different nanoscale morphologies and these charges recombine to form a local polymer-based triplet state on the sub-ns timescale (in ~300 and ~900 ps) indicated by an 1100 nm absorption band. The rate of triplet state formation is influenced by the morphology. The slower rate of charge recombination to the triplet state (in ~900 ps) belongs to a morphology that results in a higher power conversion efficiency in the corresponding device. Nanoscale morphology not only influences interfacial area and conduction of holes and electrons but also influences the mechanism of intersystem crossing (ISC). We present a model that correlates morphology to the exchange integral and fast and slow mechanisms for ISC (SOCT-ISC and H-HFI-ISC). For the pristine polymer, a flat and unstructured singlet-singlet absorption spectrum (between 900 and 1400 nm) and a very minor triplet state formation (5%) are observed at low laser fluence. René M. Williams, Hung-Cheng Chen, Daniele Di Nuzzo, Stephan C. J. Meskers, and René A. J. Janssen Copyright © 2017 René M. Williams et al. All rights reserved. Combined Raman Spectroscopy and Digital Holographic Microscopy for Sperm Cell Quality Analysis Mon, 10 Apr 2017 06:48:33 +0000 The diagnosis of male infertility is vastly complex. To date, morphology, motility, and concentration have been used as key parameters to establish the sperm normality and achieve pregnancy both in natural and in assisted fecundation. However, spermatozoa from infertile men could present a variety of alterations, such as DNA fragmentation, alterations of chromatin structure, and aneuploidy, which have been demonstrated to decrease reproductive capacity of men. Therefore, the ability to see detailed relationships between morphology and physiology in selected spermatozoa with submicrometric resolution in a nondestructive and noninvasive way and within a functional correlated context could be extremely important for the intracytoplasmic sperm injection procedure. In this review, we describe label-free optical spectroscopy and imaging techniques, based on the combination of Raman spectroscopy/imaging with holographic imaging, which are able to noninvasively measure the (bio)chemistry and morphology of sperm cells. We discuss the benefits and limitation of the proposed photonic techniques, with particular emphasis on applications in detection/characterization of sperm cell morphological defects and photodamage, and the identification/sorting of X- and Y-bearing bovine spermatozoa. A. De Angelis, S. Managò, M. A. Ferrara, M. Napolitano, G. Coppola, and A. C. De Luca Copyright © 2017 A. De Angelis et al. All rights reserved. Cavity-Enhanced Spectroscopy in Condensed Phases: Recent Literature and Remaining Challenges Wed, 29 Mar 2017 06:13:22 +0000 Recent developments in the field of cavity-enhanced spectroscopy (CES) on liquid samples are presented. The various experimental approaches to achieving the measurements are summarized, and the limitations of each approach are discussed. I conclude CES is most promising for microscale light absorption measurements on submicroliter volumes of fluid. Jonathan E. Thompson Copyright © 2017 Jonathan E. Thompson. All rights reserved. Detecting the Early Stage of Phaeosphaeria Leaf Spot Infestations in Maize Crop Using In Situ Hyperspectral Data and Guided Regularized Random Forest Algorithm Tue, 28 Mar 2017 06:55:40 +0000 Phaeosphaeria leaf spot (PLS) is considered one of the major diseases that threaten the stability of maize production in tropical and subtropical African regions. The objective of the present study was to investigate the use of hyperspectral data in detecting the early stage of PLS in tropical maize. Field data were collected from healthy and the early stage of PLS over two years (2013 and 2014) using a handheld spectroradiometer. An integration of a newly developed guided regularized random forest (GRRF) and a traditional random forest (RF) was used for feature selection and classification, respectively. The 2013 dataset was used to train the model, while the 2014 dataset was used as independent test dataset. Results showed that there were statistically significant differences in biochemical concentration between the healthy leaves and leaves that were at an early stage of PLS infestation. The newly developed GRRF was able to reduce the high dimensionality of hyperspectral data by selecting key wavelengths with less autocorrelation. These wavelengths are located at 420 nm, 795 nm, 779 nm, 1543 nm, 1747 nm, and 1010 nm. Using these variables (), a random forest classifier was able to discriminate between the healthy maize and maize at an early stage of PLS infestation with an overall accuracy of 88% and a kappa value of 0.75. Overall, our study showed potential application of hyperspectral data, GRRF feature selection, and RF classifiers in detecting the early stage of PLS infestation in tropical maize. Elhadi Adam, Houtao Deng, John Odindi, Elfatih M. Abdel-Rahman, and Onisimo Mutanga Copyright © 2017 Elhadi Adam et al. All rights reserved. Shot-Noise Limited Time-Encoded Raman Spectroscopy Wed, 22 Mar 2017 03:09:29 +0000 Raman scattering, an inelastic scattering mechanism, provides information about molecular excitation energies and can be used to identify chemical compounds. Albeit being a powerful analysis tool, especially for label-free biomedical imaging with molecular contrast, it suffers from inherently low signal levels. This practical limitation can be overcome by nonlinear enhancement techniques like stimulated Raman scattering (SRS). In SRS, an additional light source stimulates the Raman scattering process. This can lead to orders of magnitude increase in signal levels and hence faster acquisition in biomedical imaging. However, achieving a broad spectral coverage in SRS is technically challenging and the signal is no longer background-free, as either stimulated Raman gain (SRG) or loss (SRL) is measured, turning a sensitivity limit into a dynamic range limit. Thus, the signal has to be isolated from the laser background light, requiring elaborate methods for minimizing detection noise. Here, we analyze the detection sensitivity of a shot-noise limited broadband stimulated time-encoded Raman (TICO-Raman) system in detail. In time-encoded Raman, a wavelength-swept Fourier domain mode locking (FDML) laser covers a broad range of Raman transition energies while allowing a dual-balanced detection for lowering the detection noise to the fundamental shot-noise limit. Sebastian Karpf, Matthias Eibl, Wolfgang Wieser, Thomas Klein, and Robert Huber Copyright © 2017 Sebastian Karpf et al. All rights reserved. Active Mode Remote Infrared Spectroscopy Detection of TNT and PETN on Aluminum Substrates Tue, 21 Mar 2017 00:00:00 +0000 Two standoff detection systems were assembled using an infrared telescope coupled to a Fourier transform infrared spectrometer, a cryocooled mercury-cadmium telluride detector, and a telescope-coupled midinfrared excitation source. Samples of the highly energetic materials (HEMs) 2,4,6-trinitrotoluene (TNT) and pentaerythritol tetranitrate (PETN) were deposited on aluminum plates and detected at several source-target distances by carrying out remote infrared spectroscopy (RIRS) measurements on the aluminum substrates in active mode. The samples tested were placed at 1–30 m for the RIRS detection experiments. The effect of the angle of incidence/collection of the IR beams on the vibrational band intensities and the signal-to-noise ratios (S/N) were investigated. Experiments were performed at ambient temperature. Surface concentrations from 50 to 400 μg/cm2 were studied. Partial least squares regression analysis was applied to the spectra obtained. Overall, RIRS detection in active mode was useful for quantifying the HEMs deposited on the aluminum plates with a high confidence level up to the target-collector distances of 1–25 m. John R. Castro-Suarez, Leonardo C. Pacheco-Londoño, Joaquín Aparicio-Bolaño, and Samuel P. Hernández-Rivera Copyright © 2017 John R. Castro-Suarez et al. All rights reserved. Using a Spectrofluorometer for Resonance Raman Spectra of Organic Molecules Tue, 21 Mar 2017 00:00:00 +0000 Scattering (Rayleigh and Raman) and fluorescence are two common light signals that frequently occur together, confusing the researchers and graduate students experimenting in molecular spectroscopy laboratories. This report is a brief study presenting a clear discrimination between the two signals mentioned, employing a common spectrofluorometer such as the PerkinElmer LS 55. Even better, the resonance Raman signal of a molecule (e.g., acetone) can be obtained elegantly using the same instrument. Vadivel Masilamani, Hamid M. Ghaithan, Mamduh J. Aljaafreh, Abdullah Ahmed, Reem al Thagafi, Saradh Prasad, and Mohamad S. Alsalhi Copyright © 2017 Vadivel Masilamani et al. All rights reserved. Kinetic Study of Atmospheric Pressure Nitrogen Plasma Afterglow Using Quantitative Electron Spin Resonance Spectroscopy Sun, 19 Mar 2017 00:00:00 +0000 Quantitative electron spin resonance spectroscopy is used to measure nitrogen atom density in atmospheric pressure dielectric barrier discharge afterglow. The experiment shows that oxygen injection into early afterglow increases the nitrogen dissociation in certain parts of the afterglow while it is decreased in the rest of the afterglow. Numerical kinetic modelling supports and explains the experimental data while the best fit provides some a priori unknown parameters such as initial concentrations and rate constants. A. Tálský, O. Štec, M. Pazderka, and V. Kudrle Copyright © 2017 A. Tálský et al. All rights reserved.