Spectroscopy - Volume 22, issue 5

Authors: O'Maille, Grace | Go, Eden P. | Hoang, Linh | Want, Elizabeth J. | Smith, Colin | O'Maille, Paul | Nordström, Anders | Morita, Hirotoshi | Qin, Chuan | Uritboonthai, Wilasinee | Apon, Junefredo | Moore, Richard | Garrett, James | Siuzdak, Gary

Article Type: Research Article

Abstract: Comprehensive detection and quantitation of metabolites from a biological source constitute the major challenges of current metabolomics research. Two chemical derivatization methodologies, butylation and amination, were applied to human serum for ionization enhancement of a broad spectrum of metabolite classes, including steroids and amino acids. LC-ESI-MS analysis of the derivatized serum samples provided a significant signal elevation across the total ion chromatogram to over a 100-fold increase in ionization efficiency. It was also demonstrated that derivatization combined with isotopically labeled reagents facilitated the relative quantitation of derivatized metabolites from individual as well as pooled samples.

Keywords: Metabolomics, human plasma, isotope labeling, quantitation, mass spectrometry

DOI: 10.3233/SPE-2008-0361

Citation: Spectroscopy, vol. 22, no. 5, pp. 327-343, 2008

Authors: Muntean, Cristina M. | Bratu, Ioan

Article Type: Research Article

Abstract: In this paper the Raman total half bandwidths of calf-thymus DNA vibrations have been measured as a function of Mn2+ ion concentration (0–600 mM), in the presence of two concentrations of Na+ cations, respectively. The dependencies of the half bandwidths and of the global relaxation times on DNA molecular subgroup structure, on Mn2+ and Na+ ions concentrations, respectively, are reported. It is shown that changes in the (sub)picosecond dynamics of molecular subgroups in calf-thymus DNA can be monitored with Raman spectroscopy. In this study the Raman band parameters for the vibrations at 729 cm−1 …(dA), 787 cm−1 (dC), 1094 cm−1 (PO2 − ), 1376 cm−1 (dA, dG, dT, dC), 1489 cm−1 (dG, dA) and 1578 cm−1 (dG, dA) of calf thymus DNA are presented. The full-widths at half-height (FWHH) of the bands in calf-thymus DNA are typically in the wavenumber range from 9 to 33.5 cm−1 . It can be observed that the molecular relaxation processes studied in this work, have a global relaxation time smaller than 1.179 ps and larger than 0.317 ps. Mn2+ -induced DNA structural changes result for the vibrations at 729 cm−1 and 787 cm−1 in smaller global relaxation times, and larger half bandwidths, respectively, as compared to the starting value of 0 mM Mn2+ . The vibrational energy transfer processes of these two subgroups (dA, dC), respectively, are slower in the case of DNA samples at 10 mM NaCl, as compared to the corresponding DNA samples at 150 mM NaCl. However, the behaviour of the global relaxation times characteristic to the bands at 729 and 787 cm−1 is similar with respect to manganese(II) ions concentration, in the case of the two values of Na+ ions content, respectively. On the contrary, the molecular dynamics is slower for the base vibrations at 1376, 1489 and 1578 cm−1 , in the case of DNA samples at 150 mM NaCl, as compared to the corresponding samples at lower Na+ concentration, in almost all Mn2+ ions concentration range. The molecular relaxation processes in these three cases, respectively, are quite different for the corresponding samples with different Na+ ions content, upon increasing divalent manganese ions concentration. The molecular dynamics characterizing the band near 1094 cm−1 of the DNA backbone PO2 − symmetric stretching vibration is faster upon increasing the Mn2+ ions concentration between 0–600 mM and seems not to be influenced by the Na+ ions content, specific to our experimental conditions. Show more

Keywords: (Sub)picosecond dynamics, calf-thymus DNA, Mn^2+ concentration, Na^+ ions, Raman spectroscopy

DOI: 10.3233/SPE-2008-0356

Citation: Spectroscopy, vol. 22, no. 5, pp. 345-359, 2008

Authors: Al-Maythalony, Bassem A. | Wazeer, Mohammed I.M. | Isab, Anvarhusein A. | Nael, M.T. | Ahmad, Saeed

Article Type: Research Article

Abstract: Reactions of imidazolidine-2-thione (Imt), 1,3-diazinane-2-thione (Diaz) and 1,3-diazipane-2-thione (Diap) with Cd(SeCN)2 in acetonitrile resulted in the formation of 2:1 tetrahedral complexes. Both solid state and solution NMR, confirm the exocyclic thione atom to be the donor in all cases. 113 Cd shielding tensors and anisotropies were calculated from the solid-state NMR spectra. Based on the solid NMR data, a distorted tetrahedral dispositions of ligands around cadmium is proposed for the Imt complex. However, when the Imt ligand is substituted with one or two R groups (where R=Me, Et or i-Pr) forming RImt or R2 Imt, a five coordinate complex …with polymeric structure [(RImt)Cd(SeCN)2 ]∞ or [(R2 Imt)Cd(SeCN)2 ]∞ is observed. Antibacterial studies of some of the complexes were carried out. Show more

Keywords: Cadmium(II) complexes, selenocyanate complexes, imidazolidine-2-thione, CP MAS NMR studies

DOI: 10.3233/SPE-2008-0359

Citation: Spectroscopy, vol. 22, no. 5, pp. 361-370, 2008

Authors: Zhang, Chang-Jiang | Cheng, Cun-Gui

Article Type: Research Article

Abstract: Horizontal attenuation total reflection–Fourier transform infrared spectroscopy (HATR–FTIR) is used to measure the FTIR of Stephania tetrandra S. Moore and Stephania cepharantha Hayata. Because they belong to the same family and the same genus Chinese traditional medicinal materials, their chemical components are very similar. In order to extrude the difference between Stephania tetrandra S. Moore and Stephania cepharantha Hayata, continuous wavelet transform (CWT) is used to decompose the FTIR of Stephania tetrandra S. Moore and Stephania cepharantha Hayata. Three main scales are selected as the feature extracting space in the CWT domain. According the distribution of FTIR of Stephania tetrandra …S. Moore and Stephania cepharantha Hayata, three feature regions are determined at every spectra band at selected three scales in the CWT domain. Thus nine feature parameters form the feature vector. The feature vector is input to the radius basis function neural network (RBFNN) to train so as to accurately classify the Stephania tetrandra S. Moore and Stephania cepharantha Hayata. 128 couples of FTIR are used to train and test the proposed method, where 78 couples of data are used as training samples and 50 couples of data are used as testing samples. Experimental results show that the accurate recognition rate between Stephania tetrandra S. Moore and Stephania cepharantha Hayata is respectively 99.8 and 99.9% by using the proposed method. Show more

Keywords: Fourier transform infrared spectroscopy, continuous wavelet transform, radius basis function neural network, Stephania tetrandra S. Moore, Stephania cepharantha Hayata

DOI: 10.3233/SPE-2008-0360

Citation: Spectroscopy, vol. 22, no. 5, pp. 371-386, 2008

Authors: Saade, Jamil | Pacheco, Marcos Tadeu Tavares | Rodrigues, Maira Regina | Silveira Jr., Landulfo

Article Type: Research Article

Abstract: Hepatitis C has become one of the higher health problems around the world. Near-infrared Raman spectroscopy had been used to spectrally differentiate among health human blood serum from the one with hepatitis C contamination in vitro. In this study a Raman spectrometer with 80 mW, 830 nm excitation, liquid-nitrogen cooled CCD and imaging spectrograph were used to collect Raman scattering from 24 blood samples (14 healthy and 10 diseased) with collection time of 120 s. It has been used an algorithm based on the Principal Components Analysis (PCA) for main spectral features identification and Mahalanobis distance for blood spectrum classification …depending on the serology. It was observed that the highest spectral differences between the two types of human blood serum were found in 1002, 1169, 1262 and 1348 cm−1 Raman bands. The spectral analysis using multivariate statistics presented good results when compared to classical diagnosis for viral hepatitis C, showing that Raman spectroscopy can classify human blood serum spectrum in one of the two categories by identifying biochemical alterations that occur in the presence of viral infections. Show more

Keywords: Raman spectroscopy, hepatitis C, laser diagnosis, PCA, blood serum, Mahalanobis distance

DOI: 10.3233/SPE-2008-0344

Citation: Spectroscopy, vol. 22, no. 5, pp. 387-395, 2008

Authors: Cheng, Cun-Gui | Tian, Yu-Mei | Jin, Wen-Ying

Article Type: Research Article

Abstract: This paper introduces a new method for the early detection of colon cancer using a combination of feature extraction based on wavelets for Fourier Transform Infrared Spectroscopy (FTIR) and classification using the Support Vector Machine (SVM). The FTIR data collected from 36 normal SD rats, 60 1,2-DMH-induced SD rats, and 44 second generation rats of those induced rats was first preprocessed. Then, 12 feature variants were extracted using continuous wavelet analysis. The extracted feature variants were then inputted into the SVM for classification of normal, dysplasia, early carcinoma, and advanced carcinoma. Among the kernel functions the SVM used, the Poly …and RBF kernels had the highest accuracy rates. The accuracy of the Poly kernel in normal, dysplasia, early carcinoma, and advanced carcinoma were 100, 97.5, 95% and 100% respectively. The accuracy of RBF kernel in normal, dysplasia, early carcinoma, and advanced carcinoma was 100, 95, 95% and 100% respectively. The results indicated that this method could effectively and easily diagnose colon cancer in its early stages. Show more

Keywords: FTIR, wavelet feature extraction, SVM, colonic earlier stage cancer

DOI: 10.3233/SPE-2008-0352

Citation: Spectroscopy, vol. 22, no. 5, pp. 397-404, 2008

Authors: Greve, Tanja M. | Andersen, Kristine B. | Nielsen, Ole F.

Article Type: Research Article

Abstract: The penetration mechanism of dimethyl sulfoxide (DMSO) in human skin in vivo and in vitro and pig ear skin in vitro was studied using attenuated total reflectance (ATR) Fourier transform (FT) infrared (IR) and near-FT-Raman spectroscopy. The results showed changes in the conformation of the skin keratins from an α-helical to a β-sheet conformation. These changes were proved to depend on the concentration of free water in the sample as DMSO tended to bind to free water before the protein-bound water was replaced and the protein conformational changes were induced. The induced conformational changes were shown to be completely reversible …as the proteins are returned to their original state within 20 h after the treatment with DMSO. The penetration depth of DMSO was shown to depend on the time of exposure – however, after only 15 min DMSO has penetrated the stratum corneum, which is the skin barrier. Show more

Keywords: Penetration, human skin in vivo, pig ear skin in vitro, attenuated total reflectance infrared spectroscopy, near Fourier transform Raman spectroscopy, dimethyl sulfoxide

DOI: 10.3233/SPE-2008-0358

Citation: Spectroscopy, vol. 22, no. 5, pp. 405-417, 2008

Authors: Al-Akhras, M.-Ali H. | Aljarrah, K. | Al-Omari, A. | Al-Khateeb, H.M. | Albiss, B.A. | Azez, K. | Makhadmeh, G.

Article Type: Research Article

Abstract: The design and slicing technique of artificial soft tissue are presented. Artificial soft tissue has optical penetration properties similar to biological tissues. The soft tissues are made of agar dissolved in water as a transparent tissue (control) incorporated with scatter materials such as polystyrene microspheres and absorbers such as artificial dairy substitute, coffee mate (Carnation Co.). The radiation's interaction with 20 and 40 keV X-ray, and visible light (400–800 nm) with different types of tissue phantoms has been investigated. The half value layer (HVL), attenuation coefficient, energy density and penetration depth through the artificial tissues has been calculated. X-ray radiation …depth show significant reduction in soft tissue incorporated with polystyrene microspheres. At extremely low energy (E), the half value layer decreases with increasing the energy, while the attenuation coefficient increase. The calculated values of the half value layers are in very good agreement with experimental results. The calculated values of effective linear attenuation coefficient, are found to be μeff (0.22–0.42). Significant reduction in superficial dose with clear image is found with 10 mm soft tissue filter used. These results suggests: possible enhancement in diagnostic imaging and reduction in excess dose to patients; artificial soft tissue can be used as filter substitute. Show more

Keywords: Tissue phantom, penetration depth, attenuation coefficient, half value layer, photodynamic therapy

DOI: 10.3233/SPE-2008-0357

Citation: Spectroscopy, vol. 22, no. 5, pp. 419-428, 2008