scholarly journals Femtosecond Stimulated Raman Microscopy in C▬H Region of Raman Spectra of Biomolecules and Its Extension to Silent and Fingerprint Regions

2020 ◽  
Author(s):  
Rajeev Ranjan ◽  
Maria Antonietta Ferrara ◽  
Luigi Sirleto
Keyword(s):  
Raman Spectra ◽  
Raman Microscopy ◽  
Stimulated Raman

Threshold for Stimulated Raman Spectra

1966 ◽  
Vol 5 (3) ◽  
pp. 473_1 ◽  
Author(s):  
R. V. Wick ◽  
T. A. Wiggins ◽  
D. H. Rank
Keyword(s):  
Raman Spectra ◽  
Stimulated Raman

Combined Vibrational Spectroscopic and Elemental Studies of 18th Century Transylvanian Stove Tiles

2020 ◽  
Author(s):  
Ioan Bratu ◽  
Constantin Marutoiu ◽  
Antonio Hernanz ◽  
Olivia Florena Nemes ◽  
M Tiplic ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Spectral Region ◽  
18Th Century ◽  
Raman Microscopy ◽  
Ftir Spectra ◽  
The Other ◽  
Processing Temperature ◽  
Railway Station ◽  
Good Agreement

Abstract Three Transylvanian fragments of some 18th century Saxon tiles obtained from excavations in the Central Railway Station Square in Sibiu (Romania) have been studied by Raman microscopy, FTIR, SEM-EDX and XRF techniques. A lead-rich aluminosilicate was found to have been used as enamel/glaze for the tile fragments. An analysis of the band components of the Raman spectra of the enamel of one fragment in the 400–1200 cm− 1 spectral region indicates that their processing temperature was in the 600–800 °C range, in good agreement with the temperature obtained from FTIR spectra of the other two tile fragments.

scholarly journals Time-Resolved Femtosecond Stimulated Raman Spectra and DFT Anharmonic Vibrational Analysis of an Electronically Excited Rhenium Photosensitizer

2020 ◽  
Vol 124 (7) ◽  
pp. 1253-1265
Author(s):  
Martin Pižl ◽  
Alessandra Picchiotti ◽  
Mateusz Rebarz ◽  
Nils Lenngren ◽  
Liu Yingliang ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Vibrational Analysis ◽  
Time Resolved ◽  
Electronically Excited ◽  
Stimulated Raman

Real-Time Monitoring of Industrial Biofilms using Confocal Raman Microscopy and Multivariate Analysis

2020 ◽  
Author(s):  
Ana Magalhaes ◽  
Pola Goldberg Oppenheimer ◽  
Tim Overton ◽  
Kevin Wright
Keyword(s):  
Cluster Analysis ◽  
Multivariate Analysis ◽  
Real Time ◽  
Raman Spectra ◽  
Bacterial Species ◽  
Raman Microscopy ◽  
Confocal Raman Microscopy ◽  
Growth Phenotype ◽  
Confocal Raman ◽  
Biofilm Development

<p>Biofilm development in industrial settings can prove costly to manufacturing and consumer health. The presence of contaminants in raw materials, finished products and on process contact surfaces negatively impacts on product quality and safety. Rapid and accurate identification of spoilage and pathogenic microorganisms is crucial to implement effective biofilm control strategies that enhance product safety. The application of confocal Raman microscopy (CRM) for non-invasive and rapid characterisation of clinical and food isolates has been reported. The question remains whether the technique can be used as an online monitoring tool for real-time measurement of biofilm build-up in dynamic manufacturing conditions.</p> <p>In this study we investigated if CRM could be used in the manufacturing environment as an alternative microbiological quality control method. We assessed if this technology is able to differentiate between bacterial species and their growth phenotype, as well as detect contaminants from process samples.</p> <p>Laboratory and industrial isolates grown under different culture conditions (planktonic, agar plates, and CDC grown biofilms), and formulated products were analysed using a confocal Raman microscope (Thermofisher DXR2xi) under optimised settings. Reference and experimental Raman spectra were collected and analysed for all test conditions [1]. Spectral similarities were evaluated by developing a microbial multivariate predictive model using a two-way orthogonal partial least squares (O2PLS) regression for cluster analysis [2].</p> <p>Optimal spectra for microbes were obtained in the fingerprint region at approximately 600 - 1800 cm<sup>-1 </sup>where characteristic peaks could be assigned to different biological macromolecules (nucleic acids, proteins, lipids and carbohydrates). Cluster analysis showed good group separation with low variation within but high variation between bacterial strains, enabling bacterial differentiation. It also highlighted the variations observed in the spectral fingerprint for planktonic, agar and biofilm growth modes. Comparative studies suggest that the peak associated with nucleotide ring stretching (~ 700 cm<sup>-1</sup>) could be used as a microbial marker for contamination in formulation.</p> <p>Our findings indicate that confocal Raman microscopy can be used for at-line monitoring of contamination in product streams. Raman spectra provide biochemical data for microbial characterisation but variations in the spectra are often difficult to observe and interpret. Multivariate statistical methods permit rapid interrogation of spectral data, with the potential to improve microbial identification. In combination with multivariate analysis, CRM can be used as an analytical tool for rapid identification of industrial isolates and differentiation of their growth phenotype.</p> <p> </p> <p><strong>References</strong></p> <p>[1] Beier, B.D., R.G. Quivey, and A.J. Berger,Raman microspectroscopy for species identification and mapping within bacterial biofilms.AMB Express, 2012. <strong>2</strong>(1): p. 35-35.</p> <p>[2] Zou, X., et al., Automatic Spectroscopic Data Categorization by Clustering Analysis (ASCLAN): A Data-Driven Approach for Distinguishing Discriminatory Metabolites for Phenotypic Subclasses.Analytical Chemistry, 2016. <strong>88</strong>(11): p. 5670-5679.</p>

scholarly journals Stimulated Raman spectra of jet-cooled ethylene

1994 ◽  
Vol 227 (3) ◽  
pp. 248-254 ◽  
Author(s):  
L. Abad ◽  
D. Bermejo ◽  
R. Escribano ◽  
V.J. Herrero ◽  
J. Santos ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Stimulated Raman
Sign in / Sign up

Export Citation Format

Share Document