Ionic homeostasis and subcellular element compartmentation

1990 ◽  
Vol 48 (2) ◽  
pp. 150-151
Author(s):  
Ann LeFurgey ◽  
Peter Ingram ◽  
J.J. Blum ◽  
M.C. Carney ◽  
L.A. Hawkey ◽  
...  
Keyword(s):  
Leishmania Major ◽  
Ionic Homeostasis ◽  
X Ray ◽  
Functional Studies ◽  
Cell Compartments ◽  
X Ray Imaging ◽  
Resolution Electron ◽  
Multiple Cell ◽  
Role Of Zn

Subcellular compartments commonly identified and analyzed by high resolution electron probe x-ray microanalysis (EPXMA) include mitochondria, cytoplasm and endoplasmic or sarcoplasmic reticulum. These organelles and cell regions are of primary importance in regulation of cell ionic homeostasis. Correlative structural-functional studies, based on the static probe method of EPXMA combined with biochemical and electrophysiological techniques, have focused on the role of these organelles, for example, in maintaining cell calcium homeostasis or in control of excitation-contraction coupling. New methods of real time quantitative x-ray imaging permit simultaneous examination of multiple cell compartments, especially those areas for which both membrane transport properties and element content are less well defined, e.g. nuclei including euchromatin and heterochromatin, lysosomes, mucous granules, storage vacuoles, microvilli. Investigations currently in progress have examined the role of Zn-containing polyphosphate vacuoles in the metabolism of Leishmania major, the distribution of Na, K, S and other elements during anoxia in kidney cell nuclel and lysosomes; the content and distribution of S and Ca in mucous granules of cystic fibrosis (CF) nasal epithelia; the uptake of cationic probes by mltochondria in cultured heart ceils; and the junctional sarcoplasmic retlculum (JSR) in frog skeletal muscle.

Role of X-Ray Imaging in the Development of Drugs

1999 ◽  
Vol 33 (2) ◽  
pp. 635-640
Author(s):  
Sanjay Saini ◽  
Raju Sharma
Keyword(s):  
X Ray ◽  
X Ray Imaging

Effect of Zn on the intermetallics formation and reliability of Sn-3.5Ag solder on a Cu pad

2007 ◽  
Vol 22 (7) ◽  
pp. 1879-1887 ◽  
Author(s):  
Y.K. Jee ◽  
Y.H. Ko ◽  
Jin Yu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Isothermal Aging ◽  
X Ray Diffraction ◽  
X Ray ◽  
Drop Tests ◽  
Joint Microstructures ◽  
Role Of Zn ◽  
Scanning Electron

Varying amounts of Zn (1, 3, and 7 wt%) were added to Sn–3.5Ag solder on a Cu pad, and the resultant solder joint microstructures after a reflow and isothermal aging (150 °C, up to 500 h) were investigated using scanning electron microscopy, energy dispersive x-ray, and x-ray diffraction, which were subsequently correlated to the results of microhardness and drop tests. Zinc was effective in improving the drop resistance of Sn–3.5Ag solder on the Cu pad, and an addition of 3 wt% Zn nearly doubled the number of drops-to-failure (Nf). The beneficial role of Zn was ascribed to suppression of Cu6Sn5 and precipitation of Zn-containing intermetallic compounds (IMCs). However, the Zn effect was reduced as Cu6Sn5 and Ag3Sn precipitated in a joint IMC layer after prolonged aging. The interface between Ag5Zn8 and Cu5Zn8 was resistant to drop impact, but two other layered IMC structures of Cu6Sn5/Cu3Sn and Cu5Zn8/Cu6Sn5 were not.

scholarly journals The role of synthesis pathway on the microstructural characteristics of sulfur-carbon composites: X-ray imaging and electrochemistry in lithium battery

2020 ◽  
Vol 472 ◽  
pp. 228424 ◽  
Author(s):  
Daniele Di Lecce ◽  
Vittorio Marangon ◽  
Wenjia Du ◽  
Dan J.L. Brett ◽  
Paul R. Shearing ◽  
...  
Keyword(s):  
Lithium Battery ◽  
Carbon Composites ◽  
Microstructural Characteristics ◽  
X Ray ◽  
X Ray Imaging

The role of 3-D rotational x-ray imaging in spinal trauma

Injury ◽  
2005 ◽  
Vol 36 (2) ◽  
pp. S98-S103 ◽  
Author(s):  
Jorrit-Jan Verlaan ◽  
Everine B van de Kraats ◽  
Wouter JA Dhert ◽  
F Cumhur Oner
Keyword(s):  
Spinal Trauma ◽  
X Ray ◽  
X Ray Imaging

scholarly journals Water migration in wood during imbibition assessed by X-ray imaging

2020 ◽  
Vol 172 ◽  
pp. 14007
Author(s):  
Benoît Martin ◽  
Julien Colin ◽  
Pin Lu ◽  
Mahamadou Mounkaila ◽  
Joel Casalinho ◽  
...  
Keyword(s):  
Computational Models ◽  
Climatic Conditions ◽  
Water Migration ◽  
Porous Network ◽  
Drying Time ◽  
X Ray ◽  
X Ray Imaging ◽  
Rigorous Treatment ◽  
Numerical Tools

In the wooden construction, structural elements are particularly exposed to external climatic conditions during the construction phase. To ensure their durability over their expected lifespan, the required drying time have to be known after a rain shower and before closing the timber structures. This question, involving coupled heat and mass transfer, can be investigated through numerical tools. The aim of this work is to provide experimental data through X-ray imaging to validate the prediction potential of computational models simulating transfer in porous media. Two complementary methods were developed to access the water migration in Norway spruce. The first one allowed to quantitatively measure spatial distribution of moisture content over time. It is based on a rigorous treatment of the X-ray beam attenuation. The second method, using a high-resolution 3D reconstruction, highlighted the role of wood rays on liquid migration within the porous network.

Relative Impact of Kernel Thickness and Moisture Content on Rice Fissuring during Drying

2018 ◽  
Vol 34 (1) ◽  
pp. 239-246 ◽  
Author(s):  
Zephania R. Odek ◽  
Terry J. Siebenmorgen ◽  
Andronikos Mauromoustakos
Keyword(s):  
Moisture Content ◽  
Drying Characteristics ◽  
X Ray ◽  
X Ray Imaging ◽  
Rough Rice ◽  
Rice Drying ◽  
Milling Yield ◽  
Moisture Desorption

Abstract.Individual kernel thickness and moisture content (MC) vary within rice panicles. These variations affect the drying characteristics of rice kernels and consequently, the milling yield. This study utilized an X-ray system augmented with an in-situ rice drying apparatus that enabled fissure detection in rough rice kernels during drying and tempering. Rough rice kernels of two long-grain cultivars (Roy J and CL XL745), each at two MC levels (20% and 16%, w.b.), were fractionated into three thickness fractions (thin <1.98 mm, medium 1.98 - 2.03 mm, and thick >2.03 mm). Kernels from each of the 12 sub-lots were dried and tempered under controlled air conditions. Fissured kernel percentages (FKP) were determined from X-ray images taken before, during, and after drying and tempering. Kernel thickness and MC both affected moisture desorption fissuring. Generally, as kernel thickness increased, the FKP increased for high-MC lots. In regards to MC, high-MC lots were more prone to fissuring than the low-MC lots. Overall, these findings highlight the role of kernel properties on fissuring during drying. Keywords: Kernel fissuring, Kernel thickness, Moisture content, Rice drying, X-ray imaging.

Attempts of Resolution of the Subunit Structure of Ferritin and Apoferritin by Electronmicroscopy

1970 ◽  
Vol 28 ◽  
pp. 268-269
Author(s):  
H. Hawkins ◽  
W. J. Mergner ◽  
R. Henkens ◽  
T. D. Kinney ◽  
B. F. Trump
Keyword(s):  
Ring Structure ◽  
Dense Core ◽  
Subunit Structure ◽  
High Molecular Weight Protein ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Compartments ◽  
Resolution Electron ◽  
Weight Protein ◽  
High Resolution Electron Micrographs

Ferritin is a high molecular weight protein (462,000), composed of 20 apparently identical subunits which form a hollow shell 120 Å in diameter (Harrison). High resolution electron micrographs reveal a dense core (Fig. 1) containing variable amounts of iron hydroxyphosphate complex surrounded by a shell of protein. The protein becomes visible by the use of negative staining in which it appears as a ring structure, the center being overlaid by the dense core (Fig. 2). X-ray diffraction (Harrison) suggested that the subunits are arranged in the form of a dodecahedron (Fig. 5). During the course of our work it became desirable to visualize directly the fine structure of the ferritin and apoferritin molecules in order to follow structural alterations which might occur in different cell compartments, particularly during the transformation of ferritin to hemosiderin in digestive vacuoles.

HREM Studies on a New Zeolite AlPO4 #5

1985 ◽  
Vol 43 ◽  
pp. 372-373
Author(s):  
R. S. Rai ◽  
M. A. O'Keefe ◽  
G. Thomas
Keyword(s):  
Molecular Sieve ◽  
Ammonium Hydroxide ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resolution Electron ◽  
Absorption Studies ◽  
Structural Details ◽  
Potential Applications

Catalytic studies demonstrate that subtle structural differences among the family of zeolites have a marked effect on catalytic properties; therefore, exact knowledge of the zeolite framework structure is desirable. The useful role of HREM in structural studies of zeolites has already been established. AlPO4#5 is a newly synthesized aluminophosphate “molecular sieve” with zeolite-like properties having potential applications as adsorbents, catalysts and catalyst supports. It differs from aluminosilicates mainly due to the substitution of Si with P in the framework. Non-connecting parallel channels spanned by 12-rings in the as-synthesized material contains tetrapropyl- ammonium hydroxide species (fig. 1). Its ideal chemical composition is TPAOH.12AlPO4 and removal of the TPAOH by calcination at 400-600°C produces a molecular sieve for which absorption studies are consistent with unconnected pores bounded by 12-rings. The structural details of AlPO4#5 have been reported recently on the basis of x-ray diffraction. As it has not been studied so far by high resolution electron microscopy, we have used a JEOL 200CX in an attempt to examine local details of its framework at atomic level, detail that x-ray diffraction fails to reveal due to averaging effects.

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