APPLICATIONS OF PIXE ANALYSIS TO STUDIES IN CELL BIOLOGY

1992 ◽  
Vol 02 (03) ◽  
pp. 417-420 ◽  
Author(s):  
SHINJI MATSUMOTO ◽  
MASAKO FURUSE ◽  
KENSUKE KITAO ◽  
TOYOYUKI ISHIHARA ◽  
KUNIHIRO SHIMA ◽  
...  
Keyword(s):  
Cell Biology ◽  
Mammalian Cells ◽  
Environmental Changes ◽  
Molecular Level ◽  
Pixe Analysis ◽  
X Ray ◽  
Preliminary Results ◽  
Linear Relationships ◽  
Element Contents

PIXE application to the measurement of cellular elements is outlined on characteristic variations of the contents of yeast, CHO, V79 and MM46 cultured mammalian cells according to environmental changes. Cellular elements from P to Br were successfully analyzed at these cells after cautious preparation of samples in filtration steps with as possible as less deterioration. We confirmed linear relationships between the X-ray yields and these element contents. The experiment was extended to an analysis of cellular substances at molecular level by scanning of specimens. Preliminary results were included.

PIXE ANALYSIS OF CELLULAR ELEMENT CONTENTS FOR INVESTIGATION OF HEAT INACTIVATION OF MAMMALIAN CELLS

1990 ◽  
Vol 01 (01) ◽  
pp. 85-92 ◽  
Author(s):  
SHINJI MATSUMOTO ◽  
KANAME TSUCHIYA ◽  
REN CHIBA
Keyword(s):  
Heat Treatment ◽  
Mammalian Cells ◽  
Heat Inactivation ◽  
V79 Cells ◽  
Cellular Element ◽  
Pixe Analysis ◽  
X Ray ◽  
Structural Modifications ◽  
Cell Numbers ◽  
Linear Relationships

PIXE analysis was successfully applied to the measurement of cellular elements of mammalian cells in relation to the study of hyperthermia. V79 cells were heated at 44.0°C for 30 min or 1 h and the following element releases or uptakes were determined with PIXE measurement of samples obtained after appropriate periods of incubation at 37°C. Linear relationships were confirmed between the produced X-ray yields of P, S, Cl, K and Ca and the cell numbers. The cellular contents P, S, and K decreased promptly after the heat treatment and recovered gradually in the following incubation. Changes in the contents of Cl and Ca did not show abrupt decreases. Curiously, the content of Ca increased after the treatment at 44.0°C for 30 min. The results suggest that various structural modifications were induced in the membrane by the heat treatment.

Microengineering the Environment of Mammalian Cells in Culture

MRS Bulletin ◽  
2005 ◽  
Vol 30 (3) ◽  
pp. 194-201 ◽  
Author(s):  
Christopher S. Chen ◽  
Xingyu Jiang ◽  
George M. Whitesides
Keyword(s):  
Cell Biology ◽  
Mammalian Cells ◽  
Soft Lithography ◽  
Materials Science ◽  
Molecular Level ◽  
Extrinsic Factors ◽  
New Techniques ◽  
Biological Responses ◽  
Physical Environments ◽  
Attached Culture

AbstractAssays based on observations of the biological responses of individual cells to their environment have the potential to make enormous contributions to cell biology and biomedicine.To carry out well-defined experiments using cells, both the environments in which the cells live and the cells themselves must be well defined. Cell-based assays are now plagued by inconsistencies and irreproducibility, and a primary challenge in the development of informative assays is to understand the fundamental bases for these inconsistencies and to limit them. It now seems that multiple factors may contribute to the variability in the response of individual cells to stimuli; some of these factors may be extrinsic to the cells, some intrinsic. New techniques based on microengineering—especially using soft lithography to pattern surfaces at the molecular level and to fabricate microfluidic systems—have provided new capabilities to address the extrinsic factors. This review discusses recent advances in materials science that provide well-defined physical environments that can be used to study cells, both individually and in groups, in attached culture. It also reviews the challenges that must be addressed in order to make cell-based assays reproducible.

EVALUATION OF PRESSED POWDERS AND THIN SECTION STANDARDS FOR MULTI-ELEMENTAL ANALYSIS BY CONVENTIONAL AND MICRO-PIXE ANALYSIS

2010 ◽  
Vol 20 (01n02) ◽  
pp. 21-28 ◽  
Author(s):  
SHINO HOMMA-TAKEDA ◽  
HIROYUKI ISO ◽  
MASAKI ITO ◽  
KYOKO SUZUKI ◽  
KEIKO HARUMOTO ◽  
...  
Keyword(s):  
Metal Concentration ◽  
Thin Section ◽  
Elemental Analysis ◽  
Calibration Line ◽  
Pixe Analysis ◽  
X Ray ◽  
Linear Relationships ◽  
Relative Standard ◽  
Homogenous Distribution ◽  
Environmental And Biological Samples

For muti-elemental analysis, various standards are used to quantify the elements consists of environmental and biological samples. In this paper two different configuration standards, pressed powders and thin section standards, were assessed for their purpose as standards by conventional and micro-PIXE analysis. Homogeneity of manganese, iron, zinc ( Zn ), copper and yttrium added to pressed powder standard materials were validated and the relative standard deviation (RSD) of the X-ray intensity of the standards was <10% within the range, 62.5–250 µg/g. We established linear relationships between the metal concentration and the specific X-ray intensity of standards containing up to 250 µg/g of these metals. A homogenous distribution of Zn added to thin section standard materials was also confirmed by 10-µm-step scanning of the standard within the range, 50–250 µg/g (RSD ~ 10%). The calibration line between the X-ray intensity obtained from a 10-µm2 area and the metal concentration was acceptable.

scholarly journals A centriolar FGR1 oncogene partner-like protein required for paraflagellar rod assembly, but not axoneme assembly in African trypanosomes

Open Biology ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 170218 ◽  
Author(s):  
Jane Harmer ◽  
Katie Towers ◽  
Max Addison ◽  
Sue Vaughan ◽  
Michael L. Ginger ◽  
...  
Keyword(s):  
Basal Body ◽  
Mitotic Spindle ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Molecular Level ◽  
African Trypanosomes ◽  
Spindle Poles ◽  
Microtubule Organizing Centres ◽  
Polar Spindle ◽  
And Function

Proteins of the FGR1 oncogene partner (or FOP) family are found at microtubule organizing centres (MTOCs) including, in flagellate eukaryotes, the centriole or flagellar basal body from which the axoneme extends. We report conservation of FOP family proteins, Tb FOPL and Tb OFD1, in the evolutionarily divergent sleeping sickness parasite Trypanosoma brucei , showing (in contrast with mammalian cells, where FOP is essential for flagellum assembly) depletion of a trypanosome FOP homologue, Tb FOPL, affects neither axoneme nor flagellum elongation. Instead, Tb FOPL depletion causes catastrophic failure in assembly of a lineage-specific, extra-axonemal structure, the paraflagellar rod (PFR). That depletion of centriolar Tb FOPL causes failure in PFR assembly is surprising because PFR nucleation commences approximately 2 µm distal from the basal body. When over-expressed with a C-terminal myc-epitope, Tb FOPL was also observed at mitotic spindle poles. Little is known about bi-polar spindle assembly during closed trypanosome mitosis, but indication of a possible additional MTOC function for Tb FOPL parallels MTOC localization of FOP-like protein TONNEAU1 in acentriolar plants. More generally, our functional analysis of Tb FOPL emphasizes significant differences in evolutionary cell biology trajectories of FOP-family proteins. We discuss how at the molecular level FOP homologues may contribute to flagellum assembly and function in diverse flagellates.

XRF and PIXE Analysis of light and Dark Adapted Ocular Tissue

1982 ◽  
Vol 40 ◽  
pp. 190-191
Author(s):  
B. J. Panessa ◽  
H. W. Kraner ◽  
J. B. Warren ◽  
K. W. Jones
Keyword(s):  
Trace Metals ◽  
Pigment Epithelium ◽  
Nerve Impulse ◽  
Light Response ◽  
Ocular Tissue ◽  
Emission Spectrometry ◽  
Retinol Dehydrogenase ◽  
Pixe Analysis ◽  
X Ray ◽  
Optimal Function

During photoexcitation the retina requires specific electrolytes and trace metals for optimal function (Na, Mg, Cl, K, Ca, S, P, Cu and Zn). According to Hagins (1981), photoexcitation and generation of a nerve impulse involves the movement of Ca from the rhodopsin-ladened membranes of the rod outer segment (ROS) to the plasmalemma, which in turn decreases the in-flow of Na into the photoreceptor, resulting in hyperpolarization. In toad isolated retinas, the presence of Ba has been found to increase the amplitude and prolong the delay of the light response (Brown and Flaming, 1978). Trace metals such as Cu, Zn and Se are essential for the activity of the metalloenzymes of the retina and retina pigment epithelium (RPE) (i.e. carbonic anhydrase, retinol dehydrogenase, tyrosinase, glutathione peroxidase, superoxide dismutase...). Therefore the content and fluctuations of these elements in the retina and choroid are of fundamental importance for the maintenance of vision. This paper presents elemental data from light and dark adapted frog ocular tissues examined by electron beam induced x-ray microanalysis, x-ray fluorescence spectrometry (XRF) and proton induced x-ray emission spectrometry (PIXE).

RNA polymerase: Preparation and structural analysis of helical polymers

1984 ◽  
Vol 42 ◽  
pp. 152-153
Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi
Keyword(s):  
Structural Analysis ◽  
Rna Polymerase ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
Helical Polymers ◽  
X Ray ◽  
E Coli ◽  
The Past ◽  
Ordered Arrays ◽  
Low Ionic Strength

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.

Defects of Platelet Function Recognized by X-Ray Imaging and Scanning Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 610-613
Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Biology ◽  
Imaging Technique ◽  
Human Platelets ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Complex Phenomena ◽  
Scanning Electron

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).

scholarly journals Tuning π-Acceptor/σ-Donor Ratio of the 2-Isocyanoazulene Ligand: Non-Fluorinated Rival of Pentafluorophenyl Isocyanide and Trifluorovinyl Isocyanide Discovered

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 981
Author(s):  
Mason D. Hart ◽  
John J. Meyers ◽  
Zachary A. Wood ◽  
Toshinori Nakakita ◽  
Jason C. Applegate ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Coordination Chemistry ◽  
Single Crystal ◽  
13C Nmr ◽  
Quantitative Assessment ◽  
X Ray ◽  
New Class ◽  
Linear Relationships ◽  
Ligand Charge Transfer ◽  
Donor Characteristics

Isocyanoazulenes (CNAz) constitute a relatively new class of isocyanoarenes that offers rich structural and electronic diversification of the organic isocyanide ligand platform. This article considers a series of 2-isocyano-1,3-X2-azulene ligands (X = H, Me, CO2Et, Br, and CN) and the corresponding zero-valent complexes thereof, [(OC)5Cr(2-isocyano-1,3-X2-azulene)]. Air- and thermally stable, X-ray structurally characterized 2-isocyano-1,3-dimethylazulene may be viewed as a non-benzenoid aromatic congener of 2,6-dimethyphenyl isocyanide (2,6-xylyl isocyanide), a longtime “workhorse” aryl isocyanide ligand in coordination chemistry. Single crystal X-ray crystallographic {Cr–CNAz bond distances}, cyclic voltametric {E1/2(Cr0/1+)}, 13C NMR {δ(13CN), δ(13CO)}, UV-vis {dπ(Cr) → pπ*(CNAz) Metal-to-Ligand Charge Transfer}, and FTIR {νN≡C, νC≡O, kC≡O} analyses of the [(OC)5Cr(2-isocyano-1,3-X2-azulene)] complexes provided a multifaceted, quantitative assessment of the π-acceptor/σ-donor characteristics of the above five 2-isocyanoazulenes. In particular, the following inverse linear relationships were documented: δ(13COtrans) vs. δ(13CN), δ(13COcis) vs. δ(13CN), and δ(13COtrans) vs. kC≡O,trans force constant. Remarkably, the net electron withdrawing capability of the 2-isocyano-1,3-dicyanoazulene ligand rivals those of perfluorinated isocyanides CNC6F5 and CNC2F3.

scholarly journals Integrated quantitative PIXE analysis and EDX spectroscopy using a laser-driven particle source

2021 ◽  
Vol 7 (3) ◽  
pp. eabc8660
Author(s):  
F. Mirani ◽  
A. Maffini ◽  
F. Casamichiela ◽  
A. Pazzaglia ◽  
A. Formenti ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Materials Science ◽  
Quantitative Information ◽  
Pixe Analysis ◽  
Materials Analysis ◽  
Particle Source ◽  
X Ray ◽  
Analysis Techniques ◽  
Sample Structure ◽  
Elemental Characterization

Among the existing elemental characterization techniques, particle-induced x-ray emission (PIXE) and energy-dispersive x-ray (EDX) spectroscopy are two of the most widely used in different scientific and technological fields. Here, we present the first quantitative laser-driven PIXE and laser-driven EDX experimental investigation performed at the Centro de Láseres Pulsados in Salamanca. Thanks to their potential for compactness and portability, laser-driven particle sources are very appealing for materials science applications, especially for materials analysis techniques. We demonstrate the possibility to exploit the x-ray signal produced by the co-irradiation with both electrons and protons to identify the elements in the sample. We show that, using the proton beam only, we can successfully obtain quantitative information about the sample structure through laser-driven PIXE analysis. These results pave the way toward the development of a compact and multifunctional apparatus for the elemental analysis of materials based on a laser-driven particle source.

scholarly journals Physical and chemical imaging of adhesive interfaces with soft X-rays

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Hiroyuki Yamane ◽  
Masaki Oura ◽  
Osamu Takahashi ◽  
Tomoko Ishihara ◽  
Noriko Yamazaki ◽  
...  
Keyword(s):  
Molecular Level ◽  
Covalent Bond ◽  
Chemical Imaging ◽  
Diglycidyl Ether ◽  
X Rays ◽  
X Ray ◽  
Covalent Bond Formation ◽  
Chemical States ◽  
The Individual ◽  
Physical And Chemical

AbstractAdhesion is an interfacial phenomenon that is critical for assembling carbon structural composites for next-generation aircraft and automobiles. However, there is limited understanding of adhesion on the molecular level because of the difficulty in revealing the individual bonding factors. Here, using soft X-ray spectromicroscopy we show the physical and chemical states of an adhesive interface composed of a thermosetting polymer of 4,4’-diaminodiphenylsulfone-cured bisphenol A diglycidyl ether adhered to a thermoplastic polymer of plasma-treated polyetheretherketone. We observe multiscale phenomena in the adhesion mechanisms, including sub-mm complex interface structure, sub-μm distribution of the functional groups, and molecular-level covalent-bond formation. These results provide a benchmark for further research to examine how physical and chemical states correlate with adhesion, and demonstrate that soft X-ray imaging is a promising approach for visualizing the physical and chemical states at adhesive interfaces from the sub-mm level to the molecular level.

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