A Method for Observation of Benign, Premalignant and Malignant Changes in Clinical Skin Tissue Samples via FT -IR Microspectroscopy

Skrebova, Natalja,Aizawa, Katsuo,Ozaki, Yukihiro,Arase, Seiji Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

Sunlight causes various types of adverse skin changes on the sun-exposed areas of the skin, in which the most hazardous one is the induction of malignant skin tumours. FT -IR spectra were obtained from specimens excised from normal skin, BCCs, SCCs, MMs, nevi, lesions of solar keratosis and Bowen's disease. Tissue samples from freshly frozen specimens were cut into 2 sections in strictly sequential order to be stained with H & E for histopathological analysis, and then to be air-dried on CaF$_2$ slide glasses for further spectral data acquisition from defined area of interest. Intra- and inter-sample variations were estimated within grouped lesion categories according to each skin component. Mean spectra for each type of tissue pathology in the 800-1800 $cm^{-1}$ / region was interpreted using the classical group frequency approach that showed the most visible differences in spectra of benign, premalignant and malignant changes directly related to protein conformation and nucleic acid bases. The relative intensity of the nucleic acid peak was increased with progression to malignancy. In addition, PCA was able to evaluate and maximise the differences in the spectra by reducing the number of variables characterizing each patient and pathology category. This type of approach to non-destructively estimate the complexity of IR-spectra of inhomogeneous samples such as skin demonstrates the advantage of FT -IR microspectroscopy to be able to observe diseased states (benign, premalignant, malignant) and distinguish them from normal against a huge background of inter- and intra-subject variability.

Characterization of Thermal Behavior of Biodegradable Poly(hydroxyalkanoate) by Two-Dimensional Correlation Spectroscopy

Young Mee Jung,Yukihiro Ozaki,Isao Noda 한국고분자학회 2006 한국고분자학회 학술대회 연구논문 초록집 Vol.2006 No.10

Two-dimensional correlation spectroscopy in protein science, a summary for past 20years

Wu, Yuqing,Zhang, Liping,Jung, Young Mee,Ozaki, Yukihiro Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.189 No.-

<P><B>Abstract</B></P> <P>Two-dimensional correlation spectroscopy (2DCOS) has been widely used to Infrared, Raman, Near IR, Optical Activity (ROA), Vibrational Circular Dichroism (VCD) and Fluorescence spectroscopy. In addition, several new developments, such as 2D hetero-correlation analysis, moving-window two-dimensional (MW2D) correlation, model based correlation (βν and <I>k</I>ν correlation analyses) have also well incorporated into protein research. They have been used to investigate secondary structure, denaturation, folding and unfolding changes of protein, and have contributed greatly to the field of protein science. This review provides an overview of the applications of 2DCOS in the field of protein science for the past 20 year, especially to memory our old friend, Dr. Boguslawa Czarnik-Matusewicz, for her great contribution in this research field. The powerful utility of 2DCOS combined with various analytical techniques in protein studies is summarized. The noteworthy developments and perspective of 2DCOS in this field are highlighted finally.</P>

Measurement of polyethylene pellets near the glass transition temperature to enhance Raman spectral selectivity among samples and improve accuracy for density determination

Kim, Saetbyeol,Shinzawa, Hideyuki,Chung, Hoeil,Ozaki, Yukihiro The Royal Society of Chemistry 2015 The Analyst Vol.140 No.6

<P>A simple and effective strategy for improving the accuracy of the multivariate determination of polyethylene (PE) density using Raman spectroscopy has been demonstrated. This strategy is based on the possibility that varied polymeric structures of the PE samples, especially at a sub-zero temperature range, would enhance their spectral selectivity, thereby potentially improving the multivariate correlation with their pre-determined physical properties such as density. For the evaluation, Raman spectra were collected at regular intervals during continuous increase of the PE temperature from cryogenic to near room temperature. Then, using partial least squares (PLS) regression, calibration models were developed to correlate the Raman spectral features collected at each time period with the reference PE density values. Interestingly, the accuracy was improved when the temperature of the PE pellets was −35 °C, near the glass transition temperature (<I>T</I><SUB>g</SUB>). To explain the improved accuracy, a two-dimensional (2D) correlation analysis was employed to detail the spectral variation induced by temperature change. Diverse segmental chain motions (so called micro-Brownian motion) predominantly occurring in the amorphous section of the PEs around <I>T</I><SUB>g</SUB> greatly enhanced the spectral selectivity among PE samples. In addition, minor β-relaxation occurring around this temperature was an additional source of the enhanced spectral selectivity. In parallel, differential scanning calorimetry (DSC) curves of the samples were also examined to check the existence of the phase transitions.</P> <P>Graphic Abstract</P><P>A simple and effective strategy for improving the accuracy of the multivariate determination of polyethylene (PE) density using Raman spectroscopy has been demonstrated. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4an02144d'> </P>

X-ray Diffraction and Infrared Spectroscopy Studies on Crystal and Lamellar Structure and CHO Hydrogen Bonding of Biodegradable Poly(hydroxyalkanoate)

Harumi Sato,Rumi Murakami,Jian Ming Zhang,Yukihiro Ozaki,Katsuhito Mori,Isao Takahashi,Hikaru Terauchi,Isao Noda 한국고분자학회 2006 Macromolecular Research Vol.14 No.4

X-ray Diffraction and Infrared Spectroscopy Studies on Crystal and Lamellar Structure and CHO Hydrogen Bonding of Biodegradable Poly(hydroxyalkanoate)

Sato Harumi,Murakami Rumi,Zhang Jianming,Ozaki Yukihiro,Mori Katsuhito,Takahashi Isao,Terauchi Hikaru,Noda Isao The Polymer Society of Korea 2006 Macromolecular Research Vol.14 No.4

Temperature-dependent, wide-angle, x-ray diffraction (WAXD) patterns and infrared (IR) spectra were measured for biodegradable poly(3-hydroxybutyrate) (PHB) and its copolymers, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) P(HB-co-HHx) (HHx=2.5, 3.4, 10.5, and 12 mol%), in order to explore their crystal and lamellar structure and their pattern of C-H...O=C hydrogen bonding. The WAXD patterns showed that the P(HB-co-HHx) copolymers have the same orthorhombic system as PHB. It was found from the temperature-dependent WAXD measurements of PHB and P(HB-co-HHx) that the a lattice parameter is more enlarged than the b lattice parameter during heating and that only the a lattice parameter shows reversibility during both heating and cooling processes. These observations suggest that an interaction occurs along the a axis in PHB and P(HB-co-HHx). This interaction seems to be due to an intermolecular C-H...O=C hydrogen bonding between the C=O group in one helical structure and the $CH_3$ group in the other helical structure. The x-ray crystallographic data of PHB showed that the distance between the O atom of the C=O group in one helical structure and the H atom of one of the three C-H bonds of the $CH_3$ group in the other helix structure is $2.63{\AA}$, which is significantly shorter than the sum of the van der Waals separation ($2.72{\AA}$). This result and the appearance of the $CH_3$ asymmetric stretching band at $3009 cm^{-1}$ suggest that there is a C-H...O=C hydrogen bond between the C=O group and the $CH_3$ group in PHB and P(HB-co-HHx). The temperature-dependent WAXD and IR measurements revealed that the crystallinity of P(HB-co-HHx) (HHx =10.5 and 12 mol%) decreases gradually from a fairly low temperature, while that of PHB and P(HB-co-HHx) (HHx = 2.5 and 3.5 mol%) remains almost unchanged until just below their melting temperatures. It was also shown from our studies that the weakening of the C-H...O = C interaction starts from just above room temperature and proceeds gradually increasing temperature. It seems that the C-H...O=C hydrogen bonding stabilizes the chain holding in the lamellar structure and affects the thermal behaviour of PHB and its copolymers.

Improved accuracy for Raman spectroscopic determination of polyethylene property by optimization of measurement temperature and elucidation of its origin by multiple perturbation two-dimensional correlation spectroscopy

Chan Park, Seok,Shinzawa, Hideyuki,Qian, Jue,Chung, Hoeil,Ozaki, Yukihiro,Arnold, Mark A. Royal Society of Chemistry 2011 The Analyst Vol.136 No.15

<P>A novel strategy is demonstrated to improve the accuracy for determination of polyethylene (PE) density using Raman spectroscopy by optimizing the temperature of sample measurement. Spectral features associated with the conformation change of the polymer induced by temperature may provide valuable information to quantify important polymer properties such as density. To evaluate possible existence of an optimal temperature providing improved quantitative accuracy, Raman spectra of PE pellets with different densities were collected at eight different temperatures from 30 to 100 °C at 10 °C intervals. Using the spectral datasets collected at each temperature, partial least squares (PLS) models were developed using the reference PE density values determined by a standard density gradient method at 23 °C. Interestingly, the most accurate determination of density was realized at 70 °C. Multiple perturbation two-dimensional (MP2D) correlation analysis and differential scanning calorimetry (DSC) were used to examine the origin of improved accuracy at 70 °C. From these analyses, the pre-melt behavior of the PE samples was identified below their melting temperatures. Structural variations induced at the pre-melt stages enhance Raman spectral selectivity among the samples, thereby providing more accurate determination of PE density. The MP2D correlation analysis revealed the unforeseen thermal behavior of PE samples and successfully explained the improved accuracy at 70 °C.</P> <P>Graphic Abstract</P><P>Optimization of Raman spectral collection temperature improved the accuracy for determination of polyethylene (PE) density. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1an15231a'> </P>

Co-adsorption of electrolyte and protein to Ag colloid observed by surface-enhanced Raman scattering

Zhou, Zhen,Yang, In-sang,Huang, Genin Gary,Ozaki, Yukihiro Royal Society of Chemistry 2010 The Analyst Vol.135 No.9

<P>Protein detection using surface-enhanced Raman scattering (SERS) usually requires electrolytes to yield an enhanced SERS signal. However, the adsorption mechanism of electrolyte and protein to Ag colloid is not yet clearly understood. In this work, we have investigated co-adsorption of NO<SUB>3</SUB><SUP>−</SUP> and lysozyme to Ag colloid using SERS. Three experimental factors including concentration of lysozyme (10<SUP>−5</SUP> and 10<SUP>−6</SUP> M), concentration of NO<SUB>3</SUB><SUP>−</SUP> (0, 1, 2, 3 and 5 mM) and drying temperature (25 and 100 °C) have been studied. The results have shown that the co-adsorption of the adsorbates (lysozyme and NO<SUB>3</SUB><SUP>−</SUP>) on a SERS substrate and the non-absorption of NO<SUB>3</SUB><SUP>−</SUP> on the substrate can be controlled by using different experimental conditions. The co-adsorption manner of lysozyme and NO<SUB>3</SUB><SUP>−</SUP> is consistent with the mechanism of double-layer adsorbates when a protein adsorbs on a solid/liquid interface. The variation in protein conformation, especially the main-chain conformation, seems to affect the adsorption manner of the adsorbates. It has been found that the final adsorption result is not affected by the addition sequence of lysozyme and NO<SUB>3</SUB><SUP>−</SUP> during the sample preparation.</P> <P>Graphic Abstract</P><P>The co-adsorption of electrolyte and protein to Ag colloid observed by SERS would be helpful in understanding the adsorption mechanism of a protein on Ag colloids, and useful in designing protocol for preparing a SERS sample for protein detection. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0an00150c'> </P>

Side-illuminated tip-enhanced Raman study of edge phonon in graphene at the electrical breakdown limit

Okuno, Yoshito,Vantasin, Sanpon,Yang, In-Sang,Son, Jangyup,Hong, Jongill,Tanaka, Yoshito Yannick,Nakata, Yasushi,Ozaki, Yukihiro,Naka, Nobuyuki American Institute of Physics 2016 Applied Physics Letters Vol.108 No.16