scispace - formally typeset
Search or ask a question
Author

Yukihiro Ozaki

Bio: Yukihiro Ozaki is an academic researcher from Kwansei Gakuin University. The author has contributed to research in topics: Raman spectroscopy & Infrared spectroscopy. The author has an hindex of 82, co-authored 1033 publications receiving 32179 citations. Previous affiliations of Yukihiro Ozaki include Kobe University & Chulalongkorn University.


Papers
More filters
Journal ArticleDOI
28 Jan 2020-ACS Nano
TL;DR: Prominent authors from all over the world joined efforts to summarize the current state-of-the-art in understanding and using SERS, as well as to propose what can be expected in the near future, in terms of research, applications, and technological development.
Abstract: The discovery of the enhancement of Raman scattering by molecules adsorbed on nanostructured metal surfaces is a landmark in the history of spectroscopic and analytical techniques. Significant experimental and theoretical effort has been directed toward understanding the surface-enhanced Raman scattering (SERS) effect and demonstrating its potential in various types of ultrasensitive sensing applications in a wide variety of fields. In the 45 years since its discovery, SERS has blossomed into a rich area of research and technology, but additional efforts are still needed before it can be routinely used analytically and in commercial products. In this Review, prominent authors from around the world joined together to summarize the state of the art in understanding and using SERS and to predict what can be expected in the near future in terms of research, applications, and technological development. This Review is dedicated to SERS pioneer and our coauthor, the late Prof. Richard Van Duyne, whom we lost during the preparation of this article.

1,768 citations

Journal ArticleDOI
TL;DR: In this paper, a new crystal modification named the α form was proposed for the crystal structure of poly(l-lactic acid) samples annealed at temperature below 120 °C.
Abstract: Recently, we reported the isothermal crystallization behaviors of poly(l-lactic acid) (PLLA) from the melt and glassy states, respectively [J. Phys. Chem. B 2004, 108, 11514; Macromolecules 2004, 37, 6433]. Surprisingly, the quite different infrared (IR) spectral evolutions occur in the two crystallization processes at different temperatures in which the same crystal modification is expected to be formed. To clarify this unusual phenomenon, the crystal modifications and thermal behavior of PLLA samples prepared under different crystallization temperatures are investigated in detail by TEM, WAXD, and FTIR techniques. On the basis of the WAXD and IR data, a new crystal modification named the α form is proposed for the crystal structure of PLLA samples annealed at temperature below 120 °C. Such crystal modification with loose 103 helical chain packing is less thermally stable than the standard α form of PLLA. This assignment can explain all the experiment observations well. Other possible mechanisms for the ...

751 citations

Journal ArticleDOI
TL;DR: In this article, a generalized two-dimensional correlation spectroscopy (2D correlation spectrum) was proposed for the analysis of spectra collected during the crystallization of biodegradable polymer poly(3-hydroxybutyrate-co-3hydroxyhexanoate) to demonstrate the merits of this technique, such as enhancement of spectral resolution, detection of coordinated changes among spectral signals, and determination of relative directions and sequential order of intensity variations.
Abstract: Publisher Summary Generalized two-dimensional (2D) correlation spectroscopy is described to show how this technique can be applied to a very broad range of spectral analysis problems. In this spectroscopy, the underlying similarity or dissimilarity among systematic variations in spectroscopic signal intensities is examined. It develops parallel to multiple pulse-based 2D spectroscopy techniques and employs a somewhat different approach to constructing 2D spectra. The signal variations are induced by an external perturbation or physical stimulus applied to the sample, and the pattern of the intensity variation is systematically analyzed by a simple cross-correlation technique. The correlation intensities thus obtained are displayed in the form of a 2D map defined by two independent spectral axes for further analysis. Such a 2D map is referred to as a 2D correlation spectrum, even though many of today's 2D correlation studies include applications in the field outside of spectroscopy, such as chromatography and microscopy. An illustrative example is given for the analysis of attenuated total reflection (ATR) IR spectra collected during the crystallization of biodegradable polymer poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) to demonstrate the merits of this technique, such as the enhancement of spectral resolution, detection of coordinated changes among spectral signals, and determination of relative directions and sequential order of intensity variations.

736 citations

Book
15 Jul 2002
TL;DR: In this paper, the authors present a generalized two-dimensional correlation analysis for 2D Spectroscopy, which is based on the concept of correlation in another dimension, and compare it with the traditional 2D correlation analysis.
Abstract: Preface.Acknowledgements.1 Introduction.1.1 Two-dimensional Spectroscopy.1.2 Overview of the Field.1.3 Generalized Two-dimensional Correlation.1.3.1 Types of Spectroscopic Probes.1.3.2 External Perturbations.1.4 Heterospectral Correlation.1.5 Universal Applicability.2 Principle of Two-dimensional Correlation Spectroscopy.2.1 Two-dimensional Correlation Spectroscopy.2.1.1 General Scheme.2.1.2 Type of External Perturbations.2.2 Generalized Two-dimensional Correlation.2.2.1 Dynamic Spectrum.2.2.2 Two-dimensional Correlation Concept.2.2.3 Generalized Two-dimensional Correlation Function.2.2.4 Heterospectral Correlation.2.3 Properties of 2D Correlation Spectra.2.3.1 Synchronous 2D Correlation Spectrum.2.3.2 Asynchronous 2D Correlation Spectrum.2.3.3 Special Cases and Exceptions.2.4 Analytical Expressions for Certain 2D Spectra.2.4.1 Comparison of Linear Functions.2.4.2 2D Spectra Based on Sinusoidal Signals.2.4.3 Exponentially Decaying Intensities.2.4.4 Distributed Lorentzian Peaks.2.4.5 Signals with more Complex Waveforms.2.5 Cross-correlation Analysis and 2D Spectroscopy.2.5.1 Cross-correlation Function and Cross Spectrum.2.5.2 Cross-correlation Function and Synchronous Spectrum.2.5.3 Hilbert Transform.2.5.4 Orthogonal Correlation Function and Asynchronous Spectrum.2.5.5 Disrelation Spectrum.3 Practical Computation of Two-dimensional Correlation Spectra.3.1 Computation of 2D Spectra from Discrete Data.3.1.1 Synchronous Spectrum.3.1.2 Asynchronous Spectrum.3.2 Unevenly Spaced Data.3.3 Disrelation Spectrum.3.4 Computational Efficiency.4 Generalized Two-dimensional Correlation Spectroscopy in Practice.4.1 Practical Example.4.1.1 Solvent Evaporation Study.4.1.2 2D Spectra Generated from Experimental Data.4.1.3 Sequential Order Analysis by Cross Peak Signs.4.2 Pretreatment of Data.4.2.1 Noise Reduction Methods.4.2.2 Baseline Correction Methods.4.2.3 Other Pretreatment Methods.4.3 Features Arising from Factors other than Band Intensity Changes.4.3.1 Effect of Band Position Shift and Line Shape Change.4.3.2 Simulation Studies.4.3.3 2D Spectral Features from Band Shift and Line Broadening.5 Further Expansion of Generalized Two-dimensional Correlation Spectroscopy - Sample-Sample Correlation and Hybrid Correlation.5.1 Sample-Sample Correlation Spectroscopy.5.1.1 Correlation in another Dimension.5.1.2 Matrix Algebra Outlook of 2D Correlation.5.1.3 Sample-Sample Correlation Spectra.5.1.4 Application of Sample-Sample Correlation.5.2 Hybrid 2D Correlation Spectroscopy.5.2.1 Multiple Perturbations.5.2.2 Correlation between Data Matrices.5.2.3 Case Studies.5.3 Additional Remarks.6 Additional Developments in Two-dimensional Correlation Spectroscopy - Statistical Treatments, Global Phase Maps, and Chemometrics.6.1 Classical Statistical Treatments and 2D Spectroscopy.6.1.1 Variance, Covariance, and Correlation Coefficient.6.1.2 Interpretation of 2D Disrelation Spectrum.6.1.3 Coherence and Correlation Phase Angle.6.1.4 Correlation Enhancement.6.2 Global 2D Phase Maps.6.2.1 Further Discussion on Global Phase.6.2.2 Phase Map with a Blinding Filter.6.2.3 Simulation Study.6.3 Chemometrics and 2D Correlation Spectroscopy.6.3.1 Comparison between Chemometrics and 2D Correlation.6.3.2 Factor Analysis.6.3.3 Principal Component Analysis (PCA).6.3.4 Number of Principal Factors.6.3.5 PCA-reconstructed Spectra.6.3.6 Eigenvalue Manipulating Transformation (EMT).7 Other Types of Two-dimensional Spectroscopy.7.1 Nonlinear Optical 2D Spectroscopy.7.1.1 Ultrafast Laser Pulses.7.1.2 Comparison with Generalized 2D Correlation Spectroscopy.7.1.3 Overlap Between Generalized 2D Correlation and Nonlinear Spectroscopy.7.2 Statistical 2D Correlation Spectroscopy.7.2.1 Statistical 2D Correlation by Barton II et al.7.2.2 Statistical 2D Correlation by Sa sic and Ozaki.7.2.3 Other Statistical 2D Spectra.7.2.4 Link to Chemometrics.7.3 Other Developments in 2D Correlation Spectroscopy.7.3.1 Moving-window Correlation.7.3.2 Model-based 2D Correlation Spectroscopy.8 Dynamic Two-dimensional Correlation Spectroscopy Based on Periodic Perturbations.8.1 Dynamic 2D IR Spectroscopy.8.1.1 Sinusoidal Signals8.1.2 Small-amplitude Perturbation and Linear Response.8.1.3 Dynamic IR Linear Dichroism (DIRLD).8.1.4 2D Correlation Analysis of Dynamic IR Dichroism.8.2 Dynamic 2D IR Dichroism Spectra of Polymers.8.2.1 Polystyrene/Polyethylene Blend.8.2.2 Polystyrene.8.2.3 Poly(methyl methacrylate).8.2.4 Human Skin Stratum Corneum.8.2.5 Human Hair Keratin.8.2.6 Toluene and Dioctylphthalate in a Polystyrene Matrix.8.2.7 Polystyrene/Poly(vinyl methyl ether) Blend.8.2.8 Linear Low Density Polyethylene.8.2.9 Poly(hydroxyalkanoates).8.2.10 Block Copolymers.8.2.11 Summary.8.3 Repetitive Perturbations Beyond DIRLD.8.3.1 Time-resolved Small Angle X-ray Scattering (SAXS).8.3.2 Depth-profiling Photoacoustic Spectroscopy.8.3.3 Dynamic Fluorescence Spectroscopy.8.3.4 Summary.9 Applications of Two-dimensional Correlation Spectroscopy to Basic Molecules.9.1 2D IR Study of the Dissociation of Hydrogen-bonded N-Methylacetamide.9.2 2D NIR Sample-Sample Correlation Study of Phase Transitions of Oleic Acid.9.3 2D NIR Correlation Spectroscopy Study of Water.9.4 2D Fluorescence Study of Polynuclear Aromatic Hydrocarbons.10 Generalized Two-dimensional Correlation Studies of Polymers and Liquid Crystals.10.1 Temperature and Pressure Effects on Polyethylene.10.2 Reorientation of Nematic Liquid Crystals by an Electric Field.10.3 Temperature-dependent 2D NIR of Amorphous Polyamide.10.4 Composition-based 2D Raman Study of EVA Copolymers.10.5 Polarization Angle-dependent 2D IR Study of Ferroelectric Liquid Crystals.11 Two-dimensional Correlation Spectroscopy and Chemical Reactions.11.1 2D ATR/IR Study of Bis(hydroxyethyl terephthalate) Oligomerization.11.2 Hydrogen-Deuterium Exchange of Human Serum Albumin.12 Protein Research by Two-dimensional Correlation Spectroscopy.12.1 Adsorption and Concentration-dependent 2D ATR/IR Study of beta-Lactoglobulin.12.2 pH-dependent 2D ATR/IR Study of Human Serum Albumin.12.2.1 N Isomeric Form of HAS.12.2.2 N-F Transition Region of HAS.12.3 Aggregation of Lipid-bound Cytochrome c.13 Applications of Two-dimensional Correlation Spectroscopy to Biological and Biomedical Sciences.13.1 2D NIR Study of Milk.13.2 2D IR Study of Synthetic and Biological Apatites.13.3 Identification and Quality Control of Traditional Chinese Medicines.14 Application of Heterospectral Correlation Analysis.14.1 Correlation between different Spectral Measurements.14.2 SAXS/IR Dichroism Correlation Study of Block Copolymer.14.3 Raman/NIR Correlation Study of Partially Miscible Blends.14.4 ATR/IR-NIR Correlation Study of BIS (hydroxyethyl terephthalate) Oligomerization.14.5 XAS/Raman Correlation Study of Electrochemical Reaction of Lithium with CoO.15 Extension of Two-dimensional Correlation Analysis to Other Fields.15.1 Applications of 2D Correlation beyond Optical Spectroscopy.15.2 2D Correlation Gel Permeation Chromatography (GPC).15.2.1 Time-resolved GPC Study of a Sol-Gel Polymerization Process.15.2.2 2D GPC Correlation Maps.15.2.3 Reaction Mechanisms Deduced from the 2D GPC Study.15.3 2D Mass Spectrometry.15.4 Other Unusual Applications of 2D Correlation Analysis.15.5 Return to 2D NMR Spectroscopy.15.5.1 2D Correlation in NMR.15.5.2 Generalized Correlation (GECO) NMR.15.5.3 2D Correlation in Diffusion-ordered NMR.15.6 Future Developments.Index.

700 citations

Journal ArticleDOI
TL;DR: It is shown that MWPLSR provides a viable approach to eliminate the extra variability generated by non-composition-related factors such as the perturbations in experimental conditions and physical properties of samples.
Abstract: A new wavelength interval selection procedure, moving window partial least-squares regression (MWPLSR), is proposed for multicomponent spectral analysis. This procedure builds a series of PLS models in a window that moves over the whole spectral region and then locates useful spectral intervals in terms of the least complexity of PLS models reaching a desired error level. Based on a proposed theory demonstrating the necessity of wavelength selection, it is shown that MWPLSR provides a viable approach to eliminate the extra variability generated by non-composition-related factors such as the perturbations in experimental conditions and physical properties of samples. A salient advantage of MWPLSR is that the calibration model is very stable against the interference from non-composition-related factors. Moreover, the selection of spectral intervals in terms of the least model complexity enables the reduction of the size of a calibration sample set in calibration modeling. Two strategies are suggested for coupling the MWPLSR procedure with PLS for multicomponent spectral analysis: One is the inclusion of all selected intervals to develop a PLS calibration model, and the other is the combination of the PLS models built separately in each interval. The combination of multiple PLS models offers a novel potential tool for improving the performance of individual models. The proposed procedures are evaluated using two open-path Fourier transform infrared data sets and one near-infrared data set, each having different noise characteristics. The results reveal that the proposed procedures are very promising for vibrational spectroscopy-based multicomponent analyses and give much better prediction than the full-spectrum PLS modeling.

417 citations


Cited by
More filters
Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

29,323 citations

01 Jan 2014
TL;DR: These standards of care are intended to provide clinicians, patients, researchers, payors, and other interested individuals with the components of diabetes care, treatment goals, and tools to evaluate the quality of care.
Abstract: XI. STRATEGIES FOR IMPROVING DIABETES CARE D iabetes is a chronic illness that requires continuing medical care and patient self-management education to prevent acute complications and to reduce the risk of long-term complications. Diabetes care is complex and requires that many issues, beyond glycemic control, be addressed. A large body of evidence exists that supports a range of interventions to improve diabetes outcomes. These standards of care are intended to provide clinicians, patients, researchers, payors, and other interested individuals with the components of diabetes care, treatment goals, and tools to evaluate the quality of care. While individual preferences, comorbidities, and other patient factors may require modification of goals, targets that are desirable for most patients with diabetes are provided. These standards are not intended to preclude more extensive evaluation and management of the patient by other specialists as needed. For more detailed information, refer to Bode (Ed.): Medical Management of Type 1 Diabetes (1), Burant (Ed): Medical Management of Type 2 Diabetes (2), and Klingensmith (Ed): Intensive Diabetes Management (3). The recommendations included are diagnostic and therapeutic actions that are known or believed to favorably affect health outcomes of patients with diabetes. A grading system (Table 1), developed by the American Diabetes Association (ADA) and modeled after existing methods, was utilized to clarify and codify the evidence that forms the basis for the recommendations. The level of evidence that supports each recommendation is listed after each recommendation using the letters A, B, C, or E.

9,618 citations

Journal ArticleDOI
TL;DR: This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them, and summarizes cellulOSE nanoparticles in terms of particle morphology, crystal structure, and properties.
Abstract: This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The methodology of composite processing and resulting properties are fully covered, with an emphasis on neat and high fraction cellulose composites. Additionally, advances in predictive modeling from molecular dynamic simulations of crystalline cellulose to the continuum modeling of composites made with such particles are reviewed (392 references).

4,920 citations

Journal ArticleDOI
TL;DR: This review discusses the application of infrared spectroscopy to the study of proteins by focusing on the mid-infrared spectral region and theStudy of protein reactions by reaction-induced infrared difference spectroscopic.

3,596 citations