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https://www.readbyqxmd.com/read/28738659/sample-treatment-in-m%C3%A3-ssbauer-spectroscopy-for-protein-related-analyses-nondestructive-possibilities-to-look-inside-metal-containing-biosystems
#1
Alexander A Kamnev, Anna V Tugarova
In this review, the unique possibilities are considered of the (57)Fe transmission (TMS) and (57)Co emission (EMS) variants of Mössbauer (nuclear γ-resonance) spectroscopy as nondestructive techniques with minimal sample preparation/treatment and a significant analytical potential, with a focus on the analysis of cation-binding sites in metalloproteins. The techniques are shown to provide unique structural and quantitative information on the coordination microenvironment, the chemical state and transformations of the Mössbauer nuclides in sophisticated metal-containing proteins, including those within complicated supramolecular structures, and in microbial cells or tissues...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28737907/in-situ-solid-gas-reactivity-of-nanoscaled-metal-borides-from-molten-salt-synthesis
#2
Guillaume Gouget, Damien P Debecker, Ara Kim, Giorgia Olivieri, Jean-Jacques Gallet, Fabrice Bournel, Cyril Thomas, Ovidiu Ersen, Simona Moldovan, Clément Sanchez, Sophie Carenco, David Portehault
Metal borides have mostly been studied as bulk materials. The nanoscale provides new opportunities to investigate the properties of these materials, e.g., nanoscale hardening and surface reactivity. Metal borides are often considered stable solids because of their covalent character, but little is known on their behavior under a reactive atmosphere, especially reductive gases. We use molten salt synthesis at 750 °C to provide cobalt monoboride (CoB) nanocrystals embedded in an amorphous layer of cobalt(II) and partially oxidized boron as a model platform to study morphological, chemical, and structural evolutions of the boride and the superficial layer exposed to argon, dihydrogen (H2), and a mixture of H2 and carbon dioxide (CO2) through a multiscale in situ approach: environmental transmission electron microscopy, synchrotron-based near-ambient-pressure X-ray photoelectron spectroscopy, and near-edge X-ray absorption spectroscopy...
July 24, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28736221/scaffold-curvature-mediated-novel-biomineralization-process-originates-a-continuous-soft-tissue-to-bone-interface
#3
Michael Paris, Andreas Götz, Inga Hettrich, Cécile M Bidan, John W C Dunlop, Hajar Razi, Ivo Zizak, Dietmar W Hutmacher, Peter Fratzl, Georg N Duda, Wolfgang Wagermaier, Amaia Cipitria
A myriad of shapes are found in biological tissues, often naturally evolved to fulfill a particular function. In the field of tissue engineering, substrate geometry influences cell behavior and tissue formation in-vitro, yet little is known how this translates to an in-vivo scenario. Here we investigate scaffold curvature-induced tissue growth, without additional growth factors or cells, in an ovine animal model. We show that soft tissue formation follows a curvature-driven tissue growth model. The highly organized endogenous soft matrix, potentially under mechanical strain, leads to a non-standard form of biomineralization, whereby the pre-existing organic matrix is mineralized without collagen remodeling and without an intermediate cartilage ossification phase...
July 20, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28735114/determination-of-impurities-in-graphite-using-synchrotron-radiation-based-x-ray-fluorescence-spectrometry
#4
M Ghosh, K K Swain, P S Remya Devi, T A Chavan, A K Singh, M K Tiwari, R Verma
Determination of impurities namely Ca, Mn, Fe, Ni, Zn, Sr and Pb in graphite by energy dispersive X-ray fluorescence spectrometry is described using microfocused synchrotron radiation. The internal standard and standard addition methodologies were adopted for quantification and the results were compared with tube-based X-ray fluorescence spectrometry. Analysis of the results by the F and t-tests revealed their statistical equivalence. Synchrotron measurements improved the detection limits by an order of magnitude compared to the tube based technique...
July 14, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28734360/revealing-the-biography-of-a-hidden-medieval-manuscript-using-synchrotron-and-conventional-imaging-techniques
#5
E Pouyet, S Devine, T Grafakos, R Kieckhefer, J Salvant, L Smieska, A Woll, A Katsaggelos, O Cossairt, M Walton
Reading the content of hidden texts from ancient manuscripts has become an increasingly important endeavor thanks to the variety of non-destructive analytical tools and image processing routines available for this task. In this study, portable macro X-Ray Fluorescence (MA-XRF-tube), Visible Hyperspectral Imaging (HSI) together with Synchrotron based macro X-Ray Fluorescence (MA-XRF-SR) are combined with signal processing methods to reveal the biography of a degraded manuscript recycled as binding material for a 16th century printed edition of Hesiod's Works and Days...
August 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28734230/simultaneous-scanning-tunneling-microscopy-and-synchrotron-x-ray-measurements-in-a-gas-environment
#6
Rik V Mom, Willem G Onderwaater, Marcel J Rost, Maciej Jankowski, Sabine Wenzel, Leon Jacobse, Paul F A Alkemade, Vincent Vandalon, Matthijs A van Spronsen, Matthijs van Weeren, Bert Crama, Peter van der Tuijn, Roberto Felici, Wilhelmus M M Kessels, Francesco Carlà, Joost W M Frenken, Irene M N Groot
A combined X-ray and scanning tunneling microscopy (STM) instrument is presented that enables the local detection of X-ray absorption on surfaces in a gas environment. To suppress the collection of ion currents generated in the gas phase, coaxially shielded STM tips were used. The conductive outer shield of the coaxial tips can be biased to deflect ions away from the tip core. When tunneling, the X-ray-induced current is separated from the regular, 'topographic' tunneling current using a novel high-speed separation scheme...
July 14, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28733661/helical-phase-structure-of-radiation-from-an-electron-in-circular-motion
#7
M Katoh, M Fujimoto, N S Mirian, T Konomi, Y Taira, T Kaneyasu, M Hosaka, N Yamamoto, A Mochihashi, Y Takashima, K Kuroda, A Miyamoto, K Miyamoto, S Sasaki
We theoretically show that a single free electron in circular motion radiates an electromagnetic wave possessing helical phase structure, which is closely related to orbital angular momentum carried by it. We experimentally demonstrate it by interference and double-slit diffraction experiments on radiation from relativistic electrons in spiral motion. Our results indicate that photons carrying orbital angular momentum should be created naturally by cyclotron/synchrotron radiations or Compton scatterings in various situations in cosmic space...
July 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28732658/tumor-cell-uptake-and-selectivity-of-gadolinium-iii-phosphonium-complexes-the-role-of-delocalisation-at-the-phosphonium-centre
#8
Madleen Busse, Madeline S A Windsor, Alexander J Tefay, Mingyue Kardashinsky, Jacob M Fenton, Daniel E Morrison, Hugh H Harris, Louis M Rendina
The synthesis of a series of bifunctional Gd(III) complexes 1-3 covalently bound to arylphosphonium cations possessing a varying degree of delocalisation at the phosphonium centre is presented. The influence of the degree of delocalisation was investigated with regards to in vitro cytotoxicity, cellular uptake of Gd, tumor-cell selectivity and intracellular localisation of Gd within human glioblastoma (T98G) and human glial (SVG p12) cells. Cellular uptake and selectivity studies for the Gd(III) complexes indicate that a reduced delocalisation at the phosphonium centre can lead to an enhanced Gd uptake into SVG p12 cells which results in a decrease in the overall tumor cell selectivity...
July 5, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/28731757/phase-locking-the-spin-precession-in-a-storage-ring
#9
N Hempelmann, V Hejny, J Pretz, E Stephenson, W Augustyniak, Z Bagdasarian, M Bai, L Barion, M Berz, S Chekmenev, G Ciullo, S Dymov, F-J Etzkorn, D Eversmann, M Gaisser, R Gebel, K Grigoryev, D Grzonka, G Guidoboni, T Hanraths, D Heberling, J Hetzel, F Hinder, A Kacharava, V Kamerdzhiev, I Keshelashvili, I Koop, A Kulikov, A Lehrach, P Lenisa, N Lomidze, B Lorentz, P Maanen, G Macharashvili, A Magiera, D Mchedlishvili, S Mey, F Müller, A Nass, N N Nikolaev, A Pesce, D Prasuhn, F Rathmann, M Rosenthal, A Saleev, V Schmidt, Y Semertzidis, V Shmakova, A Silenko, J Slim, H Soltner, A Stahl, R Stassen, H Stockhorst, H Ströher, M Tabidze, G Tagliente, R Talman, P Thörngren Engblom, F Trinkel, Yu Uzikov, Yu Valdau, E Valetov, A Vassiliev, C Weidemann, A Wrońska, P Wüstner, P Zuprański, M Żurek
This Letter reports the successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97  GeV/c bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control both the precession rate (≈121  kHz) and the phase of the horizontal polarization component. Real time synchronization with a radio frequency (rf) solenoid made possible the rotation of the polarization out of the horizontal plane, yielding a demonstration of the feedback method to manipulate the polarization...
July 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28731105/a-comparative-vuv-absorption-mass-spectroscopy-study-on-protonated-peptides-of-different-size
#10
D Egorov, R Hoekstra, T Schlathölter
The ionization of gas-phase protonated peptides and proteins can induce molecular responses ranging from purely non-dissociative ionization to extensive multifragmentation of the system. In the case of soft X-ray photoionization, a monotonic transition between both regimes occurs in the mass range between 0.5 and 10 kDa. Despite the localized nature of the photoabsorption, excitation energy equilibrates before fragmentation sets in and the transition reflects the increase of the heat capacity with protein size...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28730614/synchrotron-tomographic-images-from-human-lung-adenocarcinoma-three-dimensional-reconstruction-and-histologic-correlations
#11
Eunjue Yi, Sung-Mi Han, Ji-Eun Chang, Hong-Tae Kim, Jong-Ki Kim, Seung-Jun Seo, Jin-Haeng Chung, Sanghoon Jheon
High-resolution tomographic images using synchrotron X-rays are expected to provide detailed reflection of microstructures, thereby allowing for the examination of histologic structures without destruction of the specimen. This study aims to evaluate the synchrotron tomographic images of mixed ground-glass opacity excised on 5-mm sections in comparison to pathologic examination. The Institutional Review Board of our institute approved this retrospective study, and written informed consent was obtained from each patient whose lung tissue would be used...
July 21, 2017: Microscopy Research and Technique
https://www.readbyqxmd.com/read/28729807/observation-of-crack-growth-in-a-polycrystalline-ferroelectric-by-synchrotron-x-ray-diffraction
#12
J E Huber, F Hofmann, S Barhli, T J Marrow, C Hildersley
Pre-cracked samples of unpoled, polycrystalline, soft ferroelectric lead zirconate titanate were subjected to electrical and mechanical loading whilst using synchrotron X-ray diffraction to map strain-fields. Clear evidence is found of switching around the crack tip and development of a crack-wake. A J-integral estimate based on strain-field data provided a sensitive measure of strain changes during loading. Electrical loading did not cause crack advance or crack-tip switching; this provides evidence for electrically permeable crack models...
November 2017: Scripta Materialia
https://www.readbyqxmd.com/read/28726575/bioprinting-pattern-dependent-electrical-mechanical-behavior-of-cardiac-alginate-implants-characterization-and-ex-vivo-phase-contrast-microtomography-assessment
#13
Mohammad Izadifar, Paul Babyn, Michael E Kelly, Dean Chapman, Xiongbiao Chen
Three-dimensional (3D)-bioprinting techniques may be used to modulate electrical/mechanical properties and porosity of hydrogel constructs for fabrication of suitable cardiac implants. Notably, characterization of these properties after implantation remains a challenge, raising the need for the development of novel quantitative imaging techniques for monitoring hydrogel implant behavior in-situ. This study aims to (i) assess the influence of hydrogel bioprinting patterns on electrical/mechanical behavior of cardiac implants based on a 3D-printing technique and (ii) investigate the potential of synchrotron X-ray phase contrast computed tomography (PCI-CT) for estimating elastic modulus/impedance/porosity and microstructural features of 3D-printed cardiac implants in-situ via an ex-vivo study...
July 20, 2017: Tissue Engineering. Part C, Methods
https://www.readbyqxmd.com/read/28723150/double-imaging-photoelectron-photoion-coincidence-sheds-new-light-on-the-dissociation-of-state-selected-ch3f-ions
#14
Xiaofeng Tang, Gustavo A Garcia, Laurent Nahon
The vacuum ultraviolet (VUV) photoionization and dissociative photoionization of methyl fluoride (CH3F) in the 12.2-19.8 eV energy range were investigated by using synchrotron radiation coupled to a double imaging photoelectron photoion coincidence (i(2)PEPICO) spectrometer. The production of several fragment ions including CH2F(+), CHF(+), CH3(+) and CH2(+) as a function of state and internal energy of CH3F(+) ions was identified and analyzed, with their individual appearance energies measured through threshold photoelectron spectroscopy...
July 19, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28721902/permeability-of-brain-tumor-vessels-induced-by-uniform-or-spatially-microfractionated-synchrotron-radiation-therapies
#15
Audrey Bouchet, Marine Potez, Nicolas Coquery, Claire Rome, Benjamin Lemasson, Elke Bräuer-Krisch, Chantal Rémy, Jean Laissue, Emmanuel L Barbier, Valentin Djonov, Raphael Serduc
PURPOSE: To compare the blood-brain barrier permeability changes induced by synchrotron microbeam radiation therapy (MRT, which relies on spatial fractionation of the incident x-ray beam into parallel micron-wide beams) with changes induced by a spatially uniform synchrotron x-ray radiation therapy. METHODS AND MATERIALS: Male rats bearing malignant intracranial F98 gliomas were randomized into 3 groups: untreated, exposed to MRT (peak and valley dose: 241 and 10...
August 1, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28718696/tumor-induced-disorder-of-iron-metabolism-in-major-organs-a-new-insight-from-chemical-speciation-of-iron
#16
Rujie Chen, Guangcun Chen
Objective To investigate the evolution of iron speciation in major organs of tumor-bearing mice and its role in cancer formation and cancer-associated complications. Methods The concentration and chemical speciation of iron in the spleen, liver, lung, kidney, heart, blood, muscle, and tumor tissue of healthy mice and tumor-bearing mice were studied by synchrotron radiation-based total reflection X-ray fluorescence spectrometry (SR-TXRF) coupled with X-ray absorption spectroscopy (XAS). Results The TXRF and XAS results showed that the iron content, especially the ferritin content, significantly decreased in the blood and spleen but significantly increased in the liver, lung, and muscle of mice after tumor implantation...
January 1, 2017: Journal of International Medical Research
https://www.readbyqxmd.com/read/28714478/immobilization-of-single-argon-atoms-in-nano-cages-of-two-dimensional-zeolite-model-systems
#17
Jian-Qiang Zhong, Mengen Wang, Nusnin Akter, John D Kestell, Alejandro M Boscoboinik, Taejin Kim, Dario J Stacchiola, Deyu Lu, J Anibal Boscoboinik
The confinement of noble gases on nanostructured surfaces, in contrast to bulk materials, at non-cryogenic temperatures represents a formidable challenge. In this work, individual Ar atoms are trapped at 300 K in nano-cages consisting of (alumino)silicate hexagonal prisms forming a two-dimensional array on a planar surface. The trapping of Ar atoms is detected in situ using synchrotron-based ambient pressure X-ray photoelectron spectroscopy. The atoms remain in the cages upon heating to 400 K. The trapping and release of Ar is studied combining surface science methods and density functional theory calculations...
July 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/28714118/body-wall-structure-in-the-starfish-asterias-rubens
#18
Liisa M Blowes, Michaela Egertová, Yankai Liu, Graham R Davis, Nick J Terrill, Himadri S Gupta, Maurice R Elphick
The body wall of starfish is composed of magnesium calcite ossicles connected by collagenous tissue and muscles and it exhibits remarkable variability in stiffness, which is attributed to the mechanical mutability of the collagenous component. Using the common European starfish Asterias rubens as an experimental animal, here we have employed a variety of techniques to gain new insights into the structure of the starfish body wall. The structure and organisation of muscular and collagenous components of the body wall were analysed using trichrome staining...
July 16, 2017: Journal of Anatomy
https://www.readbyqxmd.com/read/28713215/a-high-spatial-resolution-synchrotron-m%C3%A3-ssbauer-study-of-the-tazewell-iiicd-and-esquel-pallasite-meteorites
#19
Roberts Blukis, Rudolf Rüffer, Aleksandr I Chumakov, Richard J Harrison
Metallic phases in the Tazewell IIICD iron and Esquel pallasite meteorites were examined using (57)Fe synchrotron Mössbauer spectroscopy. Spatial resolution of ~10-20 μm was achieved, together with high throughput, enabling individual spectra to be recorded in less than 1 h. Spectra were recorded every 5-10 μm, allowing phase fractions and hyperfine parameters to be traced along transects of key microstructural features. The main focus of the study was the transitional region between kamacite and plessite, known as the "cloudy zone...
May 2017: Meteoritics & Planetary Science
https://www.readbyqxmd.com/read/28710386/seed-coat-thinning-during-horsegram-macrotyloma-uniflorum-domestication-documented-through-synchrotron-tomography-of-archaeological-seeds
#20
Charlene Murphy, Dorian Q Fuller
Reduction of seed dormancy mechanisms, allowing for rapid germination after planting, is a recurrent trait in domesticated plants, and can often be linked to changes in seed coat structure, in particular thinning. We report evidence for seed coat thinning between 2,000 BC and 1,200 BC, in southern Indian archaeological horsegram (Macrotyloma uniflorum), which it has been possible to document with high precision and non-destructively, through high resolution x-ray computed tomography using a synchrotron...
July 14, 2017: Scientific Reports
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