Characterization of Crystals in Plant Cells Using FT-IR Microspectroscopy

A combination of Fourier transform infrared (FT-IR) spectroscopy and microscopy, FT-IR microspectroscopy, has been used to characterize sections of human colorectal adenocarcinoma. In this report, a database of 2601 high quality FT-IR point spectra from 26 patient samples and seven different histological structures was recorded and analyzed. The computer-based analysis of the IR spectra was carried out in four steps: (1) an initial test for spectral quality, (2) data pre-processing, (3) data reduction and feature selection, and (4) classification of the tissue spectra by multivariate pattern recognition techniques such as hierarchical clustering and artificial neural network analysis. Furthermore, an example of how spectral databases can be utilized to reassemble false color images of tissue samples is presented. The overall classification accuracy attained by optimized artificial neural networks reached 95%, highlighting the great potential of FT-IR microspectroscopy as a potentially valuable, reagent-free technique for the characterization of tissue specimens. However, technical improvements and the compilation of validated spectral databases are essential prerequisites to make the infrared technique applicable to routine and experimental clinical analysis.

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FT-IR microspectroscopic analysis of diseased white matter brain tissues

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141214 ◽

1995 ◽

Vol 53 ◽

pp. 968-969

Author(s):

Steven M. Le Vine ◽

David L. Wetzel

Keyword(s):

White Matter ◽

Gray Matter ◽

Twitcher Mouse ◽

Grid Pattern ◽

Marked Contrast ◽

Spatially Resolved ◽

Ft Ir ◽

Ir Microspectroscopy ◽

Chemical Evidence

In situ FT-IR microspectroscopy has allowed spatially resolved interrogation of different parts of brain tissue. In previous work the spectrrscopic features of normal barin tissue were characterized. The white matter, gray matter and basal ganglia were mapped from appropriate peak area measurements from spectra obtained in a grid pattern. Bands prevalent in white matter were mostly associated with the lipid. These included 2927 and 1469 cm-1 due to CH2 as well as carbonyl at 1740 cm-1. Also 1235 and 1085 cm-1 due to phospholipid and galactocerebroside, respectively (Figs 1and2). Localized chemical changes in the white matter as a result of white matter diseases have been studied. This involved the documentation of localized chemical evidence of demyelination in shiverer mice in which the spectra of white matter lacked the marked contrast between it and gray matter exhibited in the white matter of normal mice (Fig. 3).The twitcher mouse, a model of Krabbe’s desease, was also studied. The purpose in this case was to look for a localized build-up of psychosine in the white matter caused by deficiencies in the enzyme responsible for its breakdown under normal conditions.

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Ultra-spatially resolved synchrotron powered FT-IR microspectroscopy of individual cells of biological material

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140798 ◽

1995 ◽

Vol 53 ◽

pp. 884-885

Author(s):

David L. Wetzel ◽

John A. Reffner ◽

Gwyn P. Williams

Keyword(s):

Thermal Noise ◽

Spot Size ◽

Acquisition Time ◽

Thermal Source ◽

Signal To Noise ◽

Spatially Resolved ◽

Good Spatial Resolution ◽

Small Spot ◽

Ft Ir ◽

Ir Microspectroscopy

Synchrotron radiation is 100 to 1000 times brighter than a thermal source such as a globar. It is not accompanied with thermal noise and it is highly directional and nondivergent. For these reasons, it is well suited for ultra-spatially resolved FT-IR microspectroscopy. In efforts to attain good spatial resolution in FT-IR microspectroscopy with a thermal source, a considerable fraction of the infrared beam focused onto the specimen is lost when projected remote apertures are used to achieve a small spot size. This is the case because of divergence in the beam from that source. Also the brightness is limited and it is necessary to compromise on the signal-to-noise or to expect a long acquisition time from coadding many scans. A synchrotron powered FT-IR Microspectrometer does not suffer from this effect. Since most of the unaperatured beam’s energy makes it through even a 12 × 12 μm aperture, that is a starting place for aperture dimension reduction.

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Spectral Investigation on the Growth and Characterization of NLO Crystals of Thiourea Succinic Acid Single Crystal.

International Journal of Science Technology and Humanities ◽

10.26524/ijsth58 ◽

2015 ◽

Vol 2 (2) ◽

pp. 70-73

Author(s):

Kannan.P ◽

Thambidurai.S ◽

Suresh.N

Keyword(s):

Single Crystal ◽

Succinic Acid ◽

Slow Evaporation Technique ◽

Absorption Studies ◽

Dta Analysis ◽

Evaporation Technique ◽

Ft Ir ◽

Ir Spectroscopic ◽

Thermal Stability Of

Growth of optically transparent single crystals of thiourea succinic acid (TUSA) was grown successfully from aqueous solution by slow evaporation technique. The crystal structure was elucidated using the single crystal XRD. The various functional groups and the modes of vibrations were identified by FT-IR spectroscopic analysis. The optical absorption studies indicate that the optical transparency window is quite wide making its suitable for NLO applications. Thermal stability of the crown crystal carried out by TGA-DTA analysis.

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Surface characterization of gold nanoparticles for nanomaterial specific toxicity screening: FT-IR method

10.3403/30242034u ◽

2015 ◽

Keyword(s):

Gold Nanoparticles ◽

Surface Characterization ◽

Toxicity Screening ◽

Ft Ir

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Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

Revista de Chimie ◽

10.37358/rc.17.8.5787 ◽

2017 ◽

Vol 68 (8) ◽

pp. 1895-1902

Author(s):

Ioana Cristina Tita ◽

Eleonora Marian ◽

Bogdan Tita ◽

Claudia Crina Toma ◽

Laura Vicas

Keyword(s):

Thermal Behaviour ◽

Active Substance ◽

Pharmaceutical Research ◽

Pharmaceutical Product ◽

Nitrogen Atmosphere ◽

Pure Substance ◽

Scanning Calorimetry ◽

X Ray ◽

Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

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