scholarly journals Soft X-ray induced radiation damage in thin freeze-dried brain samples studied by FTIR microscopy

2020 ◽  
Vol 27 (5) ◽  
pp. 1218-1226
Author(s):  
Artur D. Surowka ◽  
A. Gianoncelli ◽  
G. Birarda ◽  
S. Sala ◽  
N. Cefarin ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Biological Sample ◽  
Radiation Doses ◽  
Complex Interplay ◽  
Ftir Microscopy ◽  
Tissue Samples ◽  
X Ray ◽  
Freeze Dried ◽  
Resolution Limits ◽  
First Time

In order to push the spatial resolution limits to the nanoscale, synchrotron-based soft X-ray microscopy (XRM) experiments require higher radiation doses to be delivered to materials. Nevertheless, the associated radiation damage impacts on the integrity of delicate biological samples. Herein, the extent of soft X-ray radiation damage in popular thin freeze-dried brain tissue samples mounted onto Si3N4 membranes, as highlighted by Fourier transform infrared microscopy (FTIR), is reported. The freeze-dried tissue samples were found to be affected by general degradation of the vibrational architecture, though these effects were weaker than those observed in paraffin-embedded and hydrated systems reported in the literature. In addition, weak, reversible and specific features of the tissue–Si3N4 interaction could be identified for the first time upon routine soft X-ray exposures, further highlighting the complex interplay between the biological sample, its preparation protocol and X-ray probe.

On radiation damage in FIB-prepared softwood samples measured by scanning X-ray diffraction

2015 ◽  
Vol 22 (2) ◽  
pp. 267-272 ◽  
Author(s):  
Selina Storm ◽  
Malte Ogurreck ◽  
Daniel Laipple ◽  
Christina Krywka ◽  
Manfred Burghammer ◽  
...  
Keyword(s):  
Cell Wall ◽  
Radiation Damage ◽  
Focused Ion Beam ◽  
Complex Geometry ◽  
Ion Beam ◽  
Wall Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Time ◽  
Interesting System

The high flux density encountered in scanning X-ray nanodiffraction experiments can lead to severe radiation damage to biological samples. However, this technique is a suitable tool for investigating samples to high spatial resolution. The layered cell wall structure of softwood tracheids is an interesting system which has been extensively studied using this method. The tracheid cell has a complex geometry, which requires the sample to be prepared by cutting it perpendicularly to the cell wall axis. Focused ion beam (FIB) milling in combination with scanning electron microscopy allows precise alignment and cutting without splintering. Here, results of a scanning X-ray diffraction experiment performed on a biological sample prepared with a focused ion beam of gallium atoms are reported for the first time. It is shown that samples prepared and measured in this way suffer from the incorporation of gallium atoms up to a surprisingly large depth of 1 µm.

scholarly journals Dynamics of soft nanoparticle suspensions at hard X-ray FEL sources below the radiation-damage threshold

IUCrJ ◽  
2018 ◽  
Vol 5 (6) ◽  
pp. 801-807 ◽  
Author(s):  
Felix Lehmkühler ◽  
Joana Valerio ◽  
Dina Sheyfer ◽  
Wojciech Roseker ◽  
Martin A. Schroer ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Soft Matter ◽  
Damage Threshold ◽  
Correlation Spectroscopy ◽  
Time Range ◽  
Single Shot ◽  
X Ray ◽  
Nanoparticle Suspensions ◽  
Shell Particles ◽  
First Time

The application of X-ray photon correlation spectroscopy (XPCS) at free-electron laser (FEL) facilities enables, for the first time, the study of dynamics on a (sub-)nanometre scale in an unreached time range between femtoseconds and seconds. For soft-matter materials, radiation damage is a major limitation when going beyond single-shot applications. Here, an XPCS study is presented at a hard X-ray FEL on radiation-sensitive polymeric poly(N-isopropylacrylamide) (PNIPAM) nanoparticles. The dynamics of aqueous suspensions of densely packed silica-PNIPAM core-shell particles and a PNIPAM nanogel below the radiation-damage threshold are determined. The XPCS data indicate non-diffusive behaviour, suggesting ballistic and stress-dominated heterogeneous particle motions. These results demonstrate the feasibility of XPCS experiments on radiation-sensitive soft-matter materials at FEL sources and pave the way for future applications at MHz repetition rates as well as ultrafast modes using split-pulse devices.

scholarly journals Soft X-Ray Microscopy Radiation Damage On Fixed Cells Investigated With Synchrotron Radiation FTIR Microscopy

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
A. Gianoncelli ◽  
L. Vaccari ◽  
G. Kourousias ◽  
D. Cassese ◽  
D. E. Bedolla ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Radiation Damage ◽  
Ftir Microscopy ◽  
X Ray

scholarly journals X-ray radiation damage to biological samples: recent progress

2019 ◽  
Vol 26 (4) ◽  
pp. 907-911 ◽  
Author(s):  
Elspeth F. Garman ◽  
Martin Weik
Keyword(s):  
Radiation Damage ◽  
Structural Damage ◽  
Low Dose ◽  
Theoretical Calculations ◽  
Relevant Literature ◽  
Radiation Chemistry ◽  
Tissue Samples ◽  
High Quantum Efficiency ◽  
X Ray ◽  
Radiation Induced

With the continuing development of beamlines for macromolecular crystallography (MX) over the last few years providing ever higher X-ray flux densities, it has become even more important to be aware of the effects of radiation damage on the resulting structures. Nine papers in this issue cover a range of aspects related to the physics and chemistry of the manifestations of this damage, as observed in both MX and small-angle X-ray scattering (SAXS) on crystals, solutions and tissue samples. The reports include measurements of the heating caused by X-ray irradiation in ruby microcrystals, low-dose experiments examining damage rates as a function of incident X-ray energy up to 30 keV on a metallo-enzyme using a CdTe detector of high quantum efficiency as well as a theoretical analysis of the gains predicted in diffraction efficiency using these detectors, a SAXS examination of low-dose radiation exposure effects on the dissociation of a protein complex related to human health, theoretical calculations describing radiation chemistry pathways which aim to explain the specific structural damage widely observed in proteins, investigation of radiation-induced damage effects in a DNA crystal, a case study on a metallo-enzyme where structural movements thought to be mechanism related might actually be radiation-damage-induced changes, and finally a review describing what X-ray radiation-induced cysteine modifications can teach us about protein dynamics and catalysis. These papers, along with some other relevant literature published since the last Journal of Synchrotron Radiation Radiation Damage special issue in 2017, are briefly summarized below.

Quantitative energy dispersive X-ray microanalysis of eight elements in pancreatic endocrine and exocrine cells after cryo-fixation

1987 ◽  
Vol 7 (11) ◽  
pp. 859-869 ◽  
Author(s):  
Robert Norlund ◽  
Norbert Roos ◽  
Inge-Bert Täljedal
Keyword(s):  
Exocrine Pancreas ◽  
Secretory Granules ◽  
Cell Nuclei ◽  
Β Cells ◽  
Tissue Samples ◽  
Copper Surfaces ◽  
X Ray ◽  
Insulin Granules ◽  
Freeze Dried ◽  
Cellular Compartments

Quantitative X-ray microanalysis of 8 elements was performed on ultrathin, freeze-dried sections of islets and pancreas pieces from non-inbred ob/ob-mice. Diffusion of elements was reduced to a minimum by rapidly freezing the tissue samples between nitrogen-cooled polished copper surfaces and avoiding the use of chemical fixatives and stains. The ultrastructural morphology was adequately maintained to allow measurements on secretory granules, mitochondria, cell nuclei, and cytoplasm free of these organelles. The distribution of the various elements between cellular compartments was similar in islet β-cells and exocrine pancreas cells. However, the insulin secretory granules were outstanding in exhibiting the highest concentrations of zinc and calcium. In comparison with cytoplasm in the β-cells, the insulin granules accumulated calcium 2-fold and zinc as much as 40-fold. As no correlation could be made for endoplasmic reticulum in the cytoplasmic measurements areas, the true accumulations above cytosol are likely to be even higher.

Stability of freeze-dried products subjected to microcomputed tomography radiation doses

2021 ◽  
Vol 73 (2) ◽  
pp. 212-220
Author(s):  
Tim Wenzel ◽  
Achim Sack ◽  
Patrick Müller ◽  
Thorsten Poeschel ◽  
Sonja Schuldt-Lieb ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Structural Information ◽  
Microcomputed Tomography ◽  
Radiation Doses ◽  
Stability Testing ◽  
X Ray ◽  
Accelerated Stability ◽  
Freeze Dried ◽  
The Stability ◽  
Non Destructive

Abstract Objectives Microcomputed tomography (µCT) is a powerful analytical tool for non-invasive structural analysis. The stability of drug substances and formulations subjected to X-ray radiation may be a concern in the industry. This study examines the effect of X-ray radiation on the stability of freeze-dried pharmaceuticals. The investigation is a proof of concept study for the safety of µCT X-ray radiation doses during the non-destructive investigation of freeze-dried products. Methods Different formulations of clotrimazole, insulin and l-lactate dehydrogenase were freeze-dried and the products exposed to a defined dose of radiation by µCT. Conservative freeze-drying conditions were used. Irradiated and normal samples were analysed for their stability directly after freeze-drying and after stability testing. Key findings The stability of model compounds was well maintained during freeze-drying. Some degradation of all compounds occurred during accelerated stability testing. The results showed no differences between the irradiated and normal state directly after freeze-drying and accelerated stability testing. Conclusions No evidence of a detrimental effect of 100 Gy X-ray exposure on a model small molecule, peptide and protein compound was found while useful structural information could be obtained. Consequently, the technology may be useful as a non-destructive tool for product inspections if the formulation proves stable.

scholarly journals Fabry-Perot interference pattern scattered by a sub-monolayer array of nanoparticles

2022 ◽  
Author(s):  
Richard Osgood ◽  
Yassine Ait-El-Aoud ◽  
Katherine Bullion ◽  
Sean Dinneen ◽  
Richard Kingsborough ◽  
...  
Keyword(s):  
Interference Pattern ◽  
Electromagnetic Spectrum ◽  
Ftir Microscopy ◽  
X Ray ◽  
X Ray Scattering ◽  
Fabry Perot ◽  
Diagnostic Probe ◽  
First Time ◽  
Active Investigation ◽  
Ray Scattering

Abstract Understanding scattering of visible and infrared photons from nanomaterials and nanostructured materials is increasingly important for imaging, thermal management, and detection, and has implications for other parts of the electromagnetic spectrum (e.g., x-ray scattering and radar). New, interesting reports of photon scattering as a diagnostic probe, from inelastic x-ray scattering and interference to “nano-FTIR” microscopy using infrared photons, have been published and are under active investigation in laboratories around the world. Here, we report, for the first time to our best knowledge, the experimental discovery of a Fabry-Perot interference pattern that is scattered by the sub-monolayer array of plasmonic Ag nanoparticles, and confirm it analytically and with rigorous numerical FDTD simulations.

scholarly journals SEM (EDX) is an indispensable tool for the characterization of subcutaneous, preperitoneal and visceral adipose tissue of obese patients

Chemija ◽  
2018 ◽  
Vol 29 (2) ◽  
Author(s):  
Ramūnas Skaudžius ◽  
Martynas Misevičius ◽  
Vilma Brimienė ◽  
Margarita Beniušė ◽  
Gintautas Brimas ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Human Adipose Tissue ◽  
Obese Patients ◽  
Tissue Samples ◽  
X Ray ◽  
Essential Step ◽  
Indispensable Tool ◽  
Visceral Adipose ◽  
First Time

In this work the scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) elemental analysis were used for the characterization of adipose tissue samples taken from volunteer obese patients. The adipose tissue was taken from subcutaneous, preperitoneal and visceral layers of the adipose tissue. The obtained results provided information about the structural composition of adipose tissue layers in the human body, as well as the main microstructural features. It was demonstrated for the first time, to the best of our knowledge, that SEM and EDX are indispensable tools in order to investigate some special morphological features and the elemental composition of different layers of the human adipose tissue, identifying the surface microstructure and its qualitative composition. From the obtained results we concluded that such characterization of the adipose tissue is an essential step for the possible prediction of symptoms of different diseases.

Studies of metaphase chromosomes in the scanning transmission x-ray microscope: Image fidelity, radiation damage and specimen preparation

1992 ◽  
Vol 50 (2) ◽  
pp. 1038-1039
Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof
Keyword(s):  
Visible Light ◽  
Radiation Damage ◽  
Cross Section ◽  
Imaging Techniques ◽  
Dose Range ◽  
Specimen Preparation ◽  
X Rays ◽  
Metaphase Chromosomes ◽  
X Ray ◽  
Scanning Transmission

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.

Artefacts in the x-ray microanalysis of frozen-hydrated biological samples

1987 ◽  
Vol 45 ◽  
pp. 658-659
Author(s):  
Patrick Echlin
Keyword(s):  
Electron Scattering ◽  
Biological Samples ◽  
Fracture Face ◽  
Detailed Structure ◽  
X Ray ◽  
Morphological Appearance ◽  
The Poor ◽  
Freeze Dried

A number of papers have appeared recently which purport to have carried out x-ray microanalysis on fully frozen hydrated samples. It is important to establish reliable criteria to be certain that a sample is in a fully hydrated state. The morphological appearance of the sample is an obvious parameter because fully hydrated samples lack the detailed structure seen in their freeze dried counterparts. The electron scattering by ice within a frozen-hydrated section and from the surface of a frozen-hydrated fracture face obscures cellular detail. (Fig. 1G and 1H.) However, the morphological appearance alone can be quite deceptive for as Figures 1E and 1F show, parts of frozen-dried samples may also have the poor morphology normally associated with fully hydrated samples. It is only when one examines the x-ray spectra that an assurance can be given that the sample is fully hydrated.

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