B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[5664]
Open Access
Abstract: The neurodegenerative disease Friedreich's ataxia is caused by lower than normal levels of frataxin, an important protein involved in iron sulphur cluster biogenesis. An important step in designing strategies to treat this disease is to understand whether increasing the frataxin levels by gene therapy would be tout-court beneficial or detrimental since previous studies, mostly based on animal models, have reported conflicting results. Here, we have exploited an inducible model, which we developed using the CRISPR/Cas9 methodology, to study the effects of frataxin overexpression in human cells and follow how the system recovers after overexpression. Using novel tools which range from high throughput microscopy to in cell infrared, we prove that overexpression of the frataxin gene affects the cellular metabolism. It also lead to a significant increase of oxidative stress and labile iron pool levels. These cellular alterations are similar to those observed when the gene is partially silenced, as it occurs in Friedreich's ataxia's patients. Our data suggest that the levels of frataxin must be tightly regulated and fine-tuned, any imbalance leading to oxidative stress and toxicity.
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May 2018
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B22-Multimode InfraRed imaging And Microspectroscopy
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Nicholas M.
Jacques
,
Peter R. E.
Rought
,
Detlev
Fritsch
,
Mathew
Savage
,
Harry G. W.
Godfrey
,
Lei
Li
,
Tamoghna
Mitra
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Sihai
Yang
,
Martin
Schroder
Diamond Proposal Number(s):
[17709]
Abstract: The binding domains within a mixed matrix membrane (MMM) that is selective for CO2 comprising MFM-300(Al) and the polymer 6FDA-Durene-DABA have been established via in situ synchrotron IR microspectroscopy. The MOF crystals are fully accessible and play a critical role in the binding of CO2, creating a selective pathway to promote permeation of CO2 within and through the MMM. This study reveals directly the molecular mechanism for the overall enhanced performance of this MMM in terms of permeability, solubility and selectivity for CO2.
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Mar 2018
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B22-Multimode InfraRed imaging And Microspectroscopy
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Open Access
Abstract: Mycoplasma contamination represents a significant problem to the culture of mammalian cells used for research as it can cause disastrous effects on eukaryotic cells by altering cellular parameters leading to unreliable experimental results. Mycoplasma cells are very small bacteria therefore they cannot be detected by visual inspection using a visible light microscope and, thus, can remain unnoticed in the cell cultures for long periods. The detection techniques used nowadays to reveal mycoplasma contamination are time consuming and expensive with each having significant drawbacks. The ideal detection should be simple to perform with minimal preparation time, rapid, inexpensive, and sensitive. To our knowledge, for the first time, we employed Fourier transform infrared (FTIR) microspectroscopy to investigate whether we can differentiate between control cells and the same cells which have been infected with mycoplasmas during the culturing process. Chemometric methods such as HCA and PCA were used for the data analysis in order to detect spectral differences between control and intentionally infected cells, and spectral markers were revealed even at low contamination level. The preliminary results showed that FTIR has the potential to be used in the future as a reliable complementary detection technique for mycoplasma-infected cells.
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Mar 2018
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[14590]
Open Access
Abstract: Large earthquakes occur in rocks undergoing high-pressure/low-temperature metamorphism during subduction. Rhythmic major-element zoning in garnet is a common product of such metamorphism, and one that must record a fundamental subduction process. We argue that rhythmic major-element zoning in subduction zone garnets from the Franciscan Complex, California, developed in response to growth-dissolution cycles driven by pressure pulses. Using electron probe microanalysis and novel techniques in Raman and synchrotron Fourier transform infrared microspectroscopy, we demonstrate that at least four such pressure pulses, of magnitude 100–350 MPa, occurred over less than 300,000 years. These pressure magnitude and time scale constraints are most consistent with the garnet zoning having resulted from periodic overpressure development-dissipation cycles, related to pore-fluid pressure fluctuations linked to earthquake cycles. This study demonstrates that some metamorphic reactions can track individual earthquake cycles and thereby opens new avenues to the study of seismicity.
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Mar 2018
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[11766, 13725]
Open Access
Abstract: Synchrotron infrared micro-spectroscopy has been applied to measure in situ the reaction of dimethylether in single crystals of the silicoaluminophosphate STA-7. The crystals are found to contain a uniform and homogeneous distribution of acidic hydroxyl groups. Dimethylether is hydrogen bonded to the hydroxyl groups at low temperatures, but evidence is found for dissociation to form surface methoxy groups above 473 K, and aromatic hydrocarbon pool species above 573 K. From time resolved infrared measurements coupled with MS analysis of evolved products it is concluded that alkene formation occurs via a direct mechanism from reaction of dimethylether with surface methoxy groups.
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Jan 2018
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Xinran
Zhang
,
Ivan
Da Silva
,
Harry G. W.
Godfrey
,
Samantha K.
Callear
,
Sergey A.
Sapchenko
,
Yongqiang
Cheng
,
Inigo J.
Vitorica-yrezabal
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Chiu C.
Tang
,
Carlotta
Giacobbe
,
Catherine
Dejoie
,
Svemir
Rudic
,
Anibal J.
Ramirez-cuesta
,
Melissa A.
Denecke
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[14341, 14938]
Abstract: During the nuclear waste disposal process, radioactive iodine in fission product can be released. The widespread implementation of sustainable nuclear energy thus requires the development of efficient iodine stores that have simultaneously high capacity, stability and more importantly, storage density (and hence minimised system volume). Here, we report high I2 adsorption in a series of robust porous metal-organic materials, MFM-300(M) (M = Al, Sc, Fe, In). MFM-300(Sc) exhibits fully reversible I2 uptake of 1.54 g g-1 and its structure remains completely unperturbed upon inclusion/removal of I2. Direct observation and quantification of the adsorption, binding domains and dynamics of guest I2 molecules within these hosts have been achieved using XPS, TGA-MS, high resolution synchrotron X-ray diffraction, pair distribution function analysis, Raman, terahertz and neutron spectroscopy, coupled with density functional theory modelling. These complimentary techniques reveal a comprehensive understanding on the host-I2 and I2-I2 binding interaction at a molecular level. The initial binding site of I2 in MFM-300(Sc), I2I, is located near the bridging hydroxyl group of the [ScO4(OH)2] moiety [I2I···H–O = 2.263(9) Å] with an occupancy of 0.268. I2II is located interstitially between two phenyl rings of neighbouring ligand molecules [I2II···phenyl ring = 3.378(9) and 4.228(5) Å]. I2II is 4.565(2) Å from the hydroxyl group with an occupancy of 0.208. Significantly, at high I2 loading an unprecedented self-aggregation of I2 molecules into triple-helical chains within the confined nano-voids has been observed at crystallographic resolution, leading to a highly efficient packing of I2 molecules with an exceptional I2 storage density of 3.08 g cm-3 in MFM-300(Sc).
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Oct 2017
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[8153, 12570]
Open Access
Abstract: Lustering, a technique which involved the application of coloured translucent glazes over gilding and silvering was widely used to enrich and decorate altarpieces in the Baroque period. The decorations consist of a micrometric multilayered structure including several color glazes, metallic leaves and bole applied over a plaster ground. The collection of Baroque altarpieces, the oldest dating 1671 and the newest 1775 from the cathedral of Tortosa (Catalonia), is a perfect case of study of the materials used and the techniques employed throughout the period. Further information is obtained from the analysis of the reaction and aging compounds resulting from the interaction among the compounds present in the layers and between the different layers. A combination of sensitive analytical techniques, Synchrotron based μ-XRD and μ-IR and SEM-EDS which enabled the luster samples to undergo analysis without altering their original layered microstructure were selected. The nature of the compounds used to produce the yellow, green, red and blue glazes (pigments, pigment lakes and resins), metallic leaves and boles is presented. Relevant information from historical and conservation viewpoints about the origin and nature of the materials used, the making of the lusters and their reactivity and aging are also discussed.
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Sep 2017
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[14902]
Abstract: Emerging nanoporous materials, such as metal-organic frameworks (MOFs), are promising low-k dielectrics central to next-generation electronics and high-speed communication. Hitherto, the dielectric characterization of MOFs is scarce, with very limited experimental data for guiding new materials design and synthesis. Herein we demonstrate the efficacy of high-resolution synchrotron infrared (IR) specular reflectance experiments, to study the dynamic dielectric properties of a flexible MOF structure: bi-stable MIL-53(Al) that exhibits switching between a large pore (LP) and a narrow pore (NP) architecture. We show the ratio of LP:NP content of a polycrystalline sample can be changed via increased mechanical stress applied for pelletizing the MIL-53(Al) powder. We quantify the frequency-dependent dielectric constants over ~1 to 120 THz, identifying all dielectric transitions as a function of stress and phase mixtures, showing how porosity modifies MOF’s dielectric properties.
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Sep 2017
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B22-Multimode InfraRed imaging And Microspectroscopy
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Open Access
Abstract: Infrared (IR) spectral imaging is a quantitative scientific technique for measuring both the molecular composition and its spatial distribution across large areas of materials. Synchrotron radiation (SR) enhances IR imaging with a broad spectral bandwidth unobtainable with a conventional laboratory source or laser (covering 10000 to 5 cm-1), while the high collimation and small size of the SRIR source provide a diffraction-limited microbeam. The use of a few micron-sized aperture for IR imaging has a clear advantage in SR in terms of spectral quality, due to the high spectral flux reaching microspots of the sample even at the lowest wavenumbers. In this article, we present IR imaging examples developed mostly in collaboration with the user community and the staff of the IR beamline MIRIAM (Multimode InfraRed Imaging And Microspectroscopy) at Diamond Light Source [1 G. Cinque et al., Synchrotron Radiation News 24(5), 24–33 (2011).
[Taylor & Francis Online], [Google Scholar]
]. The layout of the MIRIAM beamline (B22) is shown in Figure 1. Optically, this is composed of a UHV vacuum vessel including a two periscope system each with two metal mirrors, allowing refocusing and overcoming a midway shield wall (not shown). From the right, the bending magnet source illuminates a first flat mirror (with a horizontal slot rejecting X-rays) that reflects the SRIR fan onto an ellipsoidal mirror. The SRIR is focused midway and collected by another ellipsoidal mirror that redirects it down onto a double flat mirror; this can be translated laterally to send the focused SRIR to either of the two end stations (or part of the beam to both) through wedged diamond windows. The two experimental end stations are composed of Bruker Vertex 80V in-vacuum Fourier Transform IR (FTIR) interferometers with Hyperion 3000 IR microscopes. The IR detectors are broadband or high-sensitivity MCT (mercury cadmium telluride; 100 μm or 50 μm pitch) for point-by-point microscopy, and photovoltaic MCT focal plane array (FPA) 64 × 64 pixel detectors for full-field imaging.
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Aug 2017
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[12573]
Abstract: Aortic valve is a part of the heart most frequently affected by pathological processes in humans what constitute a very serious health problem. Therefore, studies of morphology and molecular microstructure of the AV are needed. µSR- FTIR spectroscopy and microscopy represent unique tools to study chemical composition of the tissue and to identify spectroscopic markers characteristic for structural and functional features. Normal AV reveals a multi-layered structure and the compositional and structural changes within particular layers may trigger degenerative processes within the valve. Thus, deep insight into the structure of the valve to understand pathological processes occurring in AV is needed. In order to identify differences between three layers of human AV, tissue sections of macroscopically normal AV were studied using µSR- FTIR spectroscopy in combination with histological and histochemical stainings. Tissue sections deposited onto CaF2 substrates were mapped and representative set of IR spectra collected from fibrosa, spongiosa and ventricularis were analysed by Principal Component Analysis (PCA) in the spectral range between 1850–1000 cm−1 and 3050–2750 cm−1. PCA revealed a layered molecular structure of the valve and it was possible to identify IR bands associated to different tissue parts. Spongiosa layer was well differentiated from other two layers mainly based on IR bands characteristic for the distribution of glycosaminoglycans (GAGs) in the tissue – like 1170 cm−1 (υas(C-O-S)) and 1380 cm−1 (acetyl amino group). Additionally, it was distinguished from fibrosa and ventricularis based on 1085 cm−1 and 1240 cm−1 bands characteristic for GAGs and for carbohydrates- ν(C-O) and ν(C-O-C) respectively and nucleic acids -νsym(PO2−) and νasym(PO2−) respectively, which were less specific for this layer. The use of µSR- FTIR spectroscopy demonstrated co-localization of GAGs and lipids in spongiosa layer what may indicate their contribution in the very early phase of aortic valve calcific degeneration.
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Jul 2017
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