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Protein Structure and Function in the Time-Domain of Vibrational Spectroscopies. The Promising Applications of IR Synchrotron Radiation Micro-Spectroscopy

100%
Marcelli A.
Acta Physica Polonica A
|
2006
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vol. 109
|
issue 3
287-304
EN
Fourier Transform Infrared (FTIR) spectroscopy is a fundamental technique capable to characterize proteins and to investigate their conformation and dynamics in real physiological environments. Actually, a FTIR spectrum is characterized by many features, which may be correlated to the different components of the protein structure. In the last decade many relevant results have been achieved with this technique in terms of chemical imaging of proteins at subcellular level and in the investigation of cooperative phenomena. This contribution presents a few examples that illustrate the capability of the FTIR spectroscopy to investigate both protein structure and function and the opportunities offered by IR synchrotron radiation sources. Indeed the high source brilliance of these sources enables FTIR micro-spectroscopy to be performed with spatial and time resolution not available with standard sources. Moreover, the combination of synchrotron radiation and new two-dimensional detectors open new opportunities to investigate in the IR energy domain different protein processes in real time and with proteins in their native environments.
2
Content available remote

Phase Separations in Highly Correlated Materials

100%
Marcelli A.
Acta Physica Polonica A
|
2016
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vol. 129
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issue 2
264-269
EN
The X-ray absorption near edge structure spectroscopy is a unique powerful local and fast experimental method to study complex systems since it probes the nanoscale structure around selected atoms giving evidence for different local and instantaneous phases present in multiscale highly correlated granular systems. Transition metals and rare earth oxides like manganites, cuprates or pnictides superconductors show a rich variety of different competing structural, electronic and magnetic phases, which spatially coexist forming complex lattice textures. Many recent experimental data have pointed out the presence of arrested phase separation and the interplay of different phases occurring from nano- to micrometer-scale. This scenario opens the possibility to manipulate the mesoscopic phases to get new material functionalities. Therefore there is increasing need to develop methods to probe morphology and phase distribution at multiple length scales. Actually, combining X-ray imaging at high spatial resolution with μ-XANES spectroscopy both mesoscale, nanoscale and atomic structural changes can be identified. The μ-XANES spectroscopy technique is rapidly growing to investigate adaptive matter, high temperature superconductors, complex materials showing arrested phase separation at the mesoscale.
3
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Infrared Synchrotron Radiation: from Condensed Matter to Biology Researches

63%
Marcelli A., Iliescu C.
Acta Physica Polonica A
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2001
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vol. 100
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issue 5
647-658
EN
Infrared spectroscopy is probably the oldest spectroscopic method applied to investigate materials and chemico-physical phenomena. Nowadays, infrared spectroscopy represents the characterization technique most applied in the industry and in many technological processes. In the last decades a significant progress has been achieved in the use of the intense and brilliant infrared emission from electron storage rings previously used only as VUV and X-ray sources. In the infrared range the low energy of the electron beam does not affect the synchrotron radiation spectral distribution, while high current will make storage rings the most brilliant infrared sources to be used for infrared spectroscopy and micro-spectroscopy. Infrared micro-spectroscopy is a unique technique that combines microscopy and spectroscopy for purposes of micro-analysis. Spatial resolution, within a microscopic field of view, is the goal of the modern infrared micro-spectroscopy applied to condensed matter physics, materials science, biophysics, and now to medicine. Although limited in spatial resolution, infrared is able to resolve chemistry using the contrast of the absorption lines. Fourier transform-infrared micro-spectroscopy using synchrotron radiation is now able to collect data with 2-4 cm^{-1} resolution on the scale of 10-100 seconds up to an area of a few microns opening a new scenario: infrared spectroscopy of entire cells and tissue. Moreover, distributions of functional groups such as proteins, lipids, and nucleic acids can be achieved inside a single living cell with a spatial resolution of a few microns.
4
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Time Resolved IR and X-Ray Simultaneous Spectroscopy: New Opportunities for the Analysis of Fast Chemical-Physical Phenomena in Materials Science

45%
Marcelli A., Hampai D., Xu W., Malfatti L., Innocenzi P.
Acta Physica Polonica A
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2009
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vol. 115
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issue 2
489-500
EN
New powerful sources and advanced analytical techniques have been considered in the last decade to face up the continuously increasing scientific demands, in particular, in materials science. As an example, nano- science and nanotechnology researches are characterized by ultimate spatial resolution, fast and ultrafast time-resolved analysis, but the complexity of the investigated phenomena requires new analytical capabilities and new experimental techniques were introduced in the research arena. The availability all over the world of brilliant synchrotron radiation sources offers incredible opportunities. Many challenging experiments were made possible by these sources and understanding of many complex dynamical problems was obtained. Nevertheless, a strong demand of new analytical approaches, mainly based on concurrent and possibly simultaneous time-resolved experimental techniques, is emerging. Pioneering time resolved experiments combining X-ray and infrared radiation with a conventional source were performed more than a decade ago. Nowadays, many beamlines at third generation synchrotron radiation facilities are equipped with conventional sources to allow complementary techniques and the strategy of a concurrent analysis is mandatory in the investigation of many phenomena in frontier multidisciplinary researches. Moreover, new opportunities will be available by means of concurrent spectroscopic experiments investigating complex phenomena on a short timescale, from the sub-second to the microsecond time domain. We will present and discuss researches where the combination of IR and X-ray simultaneous experiments may return unique information on complex dynamical processes and phase transitions occurring in materials science. Finally, we will briefly describe the conceptual layout of a synchrotron radiation beamline to perform concurrent IR and X-ray experiments.
5
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Methodology for FTIR Imaging of Individual Cells

39%
Yao S., Cestelli Guidi M., Delugin M., Della-Ventura G., Marcelli A., Petibois C.
Acta Physica Polonica A
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2016
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vol. 129
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issue 2
250-254
EN
FTIR imaging is a novel spectroscopic technique able to provide cell imaging, in vivo and in real-time. However, one key issue is developing methodologies for cell culture on IR-transparent substrates fitting cell biology requirements. In this work we tested different IR-transparent substrates in terms of biotoxicity, surface properties, and spectral image acquisition qualities. Only a few substrates, namely Si₃N₄, Ge, GLS, LaF₃, Si, SrF₂, ZnS/C, ZnS/F, were found to provide cell culture conditions comparable to those observed on usual polycarbonate Petri dishes, the main limiting parameter being the toxicity of the material (ZnS, GLS, PbF₂, PbCl₂) or a poor adhesiveness (notably diamond, AgCl, CaF₂, ZnS). From substrates eligible for a good-quality cell culture, the spectral acquisition quality is mainly affected by the refractive index value. Finally, the best compromise between cell culture quality and image spectral quality could be obtained using Si and Ge substrates. This rationalization of the available IR-transparent substrates for bioimaging is particularly relevant for live cell analyses, where cell culture conditions must remain unaffected by substrate properties.
6
Content available remote

Application of μ-FTIR-SR Spectroscopy to Prostate Tissue Analysis

33%
Kwiatek W., Paluszkiewicz C., Banaś A., Kisiel A., Podgórczyk M., Marcelli A., Cestelli Guidi M., Piccinini M.
Acta Physica Polonica A
|
2009
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vol. 115
|
issue 2
602-605
EN
The infrared spectromicroscopy is a quite recent technique rapidly developing thanks to the availability of new instruments and new brilliant synchrotron radiation sources in different areas and in particular to biomedical researches. In order to achieve a diffraction limited spatial resolution in tissue samples, we performed experiments at SINBAD, the synchrotron infrared beamline of the Laboratori Nazionali di Frascati. We characterized the chemical composition of prostate tissue samples taken from patients affected by prostate cancer disease. Different sizes of the pinholes were considered for the measurements. In the case of prostate tissue sections the results show the possibility to determine the intensity ratio of the CH_2 and CH_3 bands set at 2930 cm^{-1} and 2960 cm^{-1}, respectively. Experiments were also performed with a pinhole of 5 μm of diameter and the differences in both histological and chemical compositions of such samples were determined.
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