The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
Marlan O. Scully - One of the best experts on this subject based on the ideXlab platform.
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Discrimination of Dipicolinic Acid and its interferents by femtosecond coherent Raman spectroscopy
Journal of Applied Physics, 2006Co-Authors: Yu Huang, Dmitry Pestov, Miaochan Zhi, Robert K. Murawski, Alexei V. Sokolov, Arthur Dogariu, Yoav Avitzour, Marlan O. ScullyAbstract:Measurements of the beat frequencies between vibrational modes of Dipicolinic Acid (DPA) and a series of other molecules (interferents) are presented. The results were obtained from femtosecond time-resolved coherent Raman scattering, and the vibrational level spacings were determined from a Fourier transform of the signal versus probe pulse delay. The entire spectrum of the generated signal is recorded in order to demonstrate multimode excitation and to explain the variety of qualitatively different traces that can be obtained for the same molecule. Since the spectral signature of DPA is unique enough to be used for identification purposes, this technique has the potential to detect hazardous bacterial species, such as anthrax spores.
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Multi-phonon absorption spectra of Dipicolinic Acid
Chemical Physics Letters, 2005Co-Authors: Nikolai G. Kalugin, Luojia Wang, Zoe-elizabeth Sariyanni, Yu. V. Rostovtsev, Marlan O. ScullyAbstract:Abstract We have determined the absorption coefficients of the IR-active vibrational modes in solid Dipicolinic Acid (DPA) at 300 K and observed, for the first time, the DPA absorption lines corresponding to vibrational overtones. Applications of obtained results to coherent Raman spectroscopy are discussed.
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Spontaneous Raman spectra of Dipicolinic Acid in microcrystalline form
Journal of Modern Optics, 2003Co-Authors: Alexandre A. Kolomenskii, Sergei N. Jerebtsov, Tomas Opatrny, Hans A. Schuessler, Marlan O. ScullyAbstract:Dipicolinic Acid (DPA) is an important component of bacterial spores. The Raman spectrum of DPA in the form of compacted powder was measured in reflection at room temperature with excitation by a nanosecond laser at 532 nm. The spectrum presents a set of characteristic frequency bands in the region 700-3090 cm � 1 that were identified with characteristic vibrational modes of the DPA molecule.
Jean-claude G. Bünzli - One of the best experts on this subject based on the ideXlab platform.
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Tuning the keto equilibrium in 4-substituted Dipicolinic Acid derivatives
Organic & biomolecular chemistry, 2003Co-Authors: Anne-sophie Chauvin, Sandrine Gras, Jean-claude G. BünzliAbstract:The synthesis of 4-substituted Dipicolinic Acid derivatives requiring palladium catalysis is described. A keto–enol equilibrium has been observed, depending on the nature of the 2,6-position substituents.
Alexei V. Sokolov - One of the best experts on this subject based on the ideXlab platform.
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Discrimination of Dipicolinic Acid and its interferents by femtosecond coherent Raman spectroscopy
Journal of Applied Physics, 2006Co-Authors: Yu Huang, Dmitry Pestov, Miaochan Zhi, Robert K. Murawski, Alexei V. Sokolov, Arthur Dogariu, Yoav Avitzour, Marlan O. ScullyAbstract:Measurements of the beat frequencies between vibrational modes of Dipicolinic Acid (DPA) and a series of other molecules (interferents) are presented. The results were obtained from femtosecond time-resolved coherent Raman scattering, and the vibrational level spacings were determined from a Fourier transform of the signal versus probe pulse delay. The entire spectrum of the generated signal is recorded in order to demonstrate multimode excitation and to explain the variety of qualitatively different traces that can be obtained for the same molecule. Since the spectral signature of DPA is unique enough to be used for identification purposes, this technique has the potential to detect hazardous bacterial species, such as anthrax spores.
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Visible and UV coherent Raman spectroscopy of Dipicolinic Acid
Proceedings of the National Academy of Sciences of the United States of America, 2005Co-Authors: Dmitry Pestov, Nikolai G. Kalugin, Zoe-elizabeth Sariyanni, Alexandre A. Kolomenskii, Hans A. Schuessler, Miaochan Zhi, Robert K. Murawski, Gerhard G. Paulus, Vladimir A. Sautenkov, Alexei V. SokolovAbstract:We use time-resolved coherent Raman spectroscopy to obtain molecule-specific signals from Dipicolinic Acid (DPA), which is a marker molecule for bacterial spores. We use femtosecond laser pulses in both visible and UV spectral regions and compare experimental results with theoretical predictions. By exciting vibrational coherence on more than one mode simultaneously, we observe a quantum beat signal that can be used to extract the parameters of molecular motion in DPA. The signal is enhanced when an UV probe pulse is used, because its frequency is near-resonant to the first excited electronic state of the molecule. The capability for unambiguous identification of DPA molecules will lead to a technique for real-time detection of spores.
Hans A. Schuessler - One of the best experts on this subject based on the ideXlab platform.
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Visible and UV coherent Raman spectroscopy of Dipicolinic Acid
Proceedings of the National Academy of Sciences of the United States of America, 2005Co-Authors: Dmitry Pestov, Nikolai G. Kalugin, Zoe-elizabeth Sariyanni, Alexandre A. Kolomenskii, Hans A. Schuessler, Miaochan Zhi, Robert K. Murawski, Gerhard G. Paulus, Vladimir A. Sautenkov, Alexei V. SokolovAbstract:We use time-resolved coherent Raman spectroscopy to obtain molecule-specific signals from Dipicolinic Acid (DPA), which is a marker molecule for bacterial spores. We use femtosecond laser pulses in both visible and UV spectral regions and compare experimental results with theoretical predictions. By exciting vibrational coherence on more than one mode simultaneously, we observe a quantum beat signal that can be used to extract the parameters of molecular motion in DPA. The signal is enhanced when an UV probe pulse is used, because its frequency is near-resonant to the first excited electronic state of the molecule. The capability for unambiguous identification of DPA molecules will lead to a technique for real-time detection of spores.
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Raman spectra of Dipicolinic Acid in crystalline and liquid environments.
Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2005Co-Authors: Alexandre A. Kolomenskii, Hans A. SchuesslerAbstract:Raman spectra of Dipicolinic Acid (DPA) are important for detection of bacterial spores, since DPA and its salts present one of their major components. The implementation of a deeply cooled CCD camera in combination with pulsed excitation at 532 nm allowed measuring well-resolved Raman spectra of the DPA in different forms. Powder preparations, crystals grown from saturated solutions and aqueous solutions of the DPA were studied. The spectral features in different environments and comparison with the spectra obtained by other methods are discussed.
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Spontaneous Raman spectra of Dipicolinic Acid in microcrystalline form
Journal of Modern Optics, 2003Co-Authors: Alexandre A. Kolomenskii, Sergei N. Jerebtsov, Tomas Opatrny, Hans A. Schuessler, Marlan O. ScullyAbstract:Dipicolinic Acid (DPA) is an important component of bacterial spores. The Raman spectrum of DPA in the form of compacted powder was measured in reflection at room temperature with excitation by a nanosecond laser at 532 nm. The spectrum presents a set of characteristic frequency bands in the region 700-3090 cm � 1 that were identified with characteristic vibrational modes of the DPA molecule.
Y.m. Lin - One of the best experts on this subject based on the ideXlab platform.
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Spore detection in aerobic granules by different Dipicolinic Acid releasing methods.
Bioresource technology, 2007Co-Authors: L. Wang, Y.m. LinAbstract:This work aimed at developing a procedure for spore quantification. Spore content was determined by analyzing Dipicolinic Acid (dpa) extracted from aerobic granules by 13 methods. Concentrated HCl was able to release dpa completely. Results showed that dpa constituted 33.7 mg per g SS, meaning that about 337 mg per g SS were spores, not the normal vegetative cells.