Correlation between Sweet Spots of Glycopeptides and Polymorphism of the Matrix Crystal in MALDI Samples

AbstractThe two basic recrystallization theories, that of oriented growth and tliat of oriented nucleation, have been reviewed in light of data obtained from growth of single grains into strained single crystals of high purity (99.99%) aluminum. It appears that a compromise of these two theories would best explain the results obtained under this investigation. Basically, the proposed theory states that a stress is developed between coherent embryo nuclei and the strained matrix crystal. The relative orientation of the embryo nucleus and the matrix coupled with the residual stress in the strained matrix crystal will determine the magnitude of the stress between the embryo arid the matrix. When this stress is of sufficient magnitude, the coherent bonds between the embryo and the matrix will rupture and the embryo will become a nucleus which can then grow and consume the matrix.Competing with this process is the phenomenon known as polygonization. Partial relief of the residual stress in the sprained crystal takes place as polygonization occurs. This partial stress relief is often sufficient to prevent the formation of nuclei and the occurrence of subsequent recrystallization.

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Crystalloid Inclusions in Hepatocyte Mitochondria and Their Similarity to Cytoplasmic Crystalloids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051001 ◽

1974 ◽

Vol 32 ◽

pp. 198-199

Author(s):

Odell T. Minick ◽

Hidejiro Yokoo

Keyword(s):

Liver Disease ◽

Alcoholic Liver Disease ◽

Special Interest ◽

Structural Variations ◽

Mitochondrial Alterations ◽

The Matrix ◽

Crystalloid Inclusions ◽

Liver Biopsies

Mitochondrial alterations were studied in 25 liver biopsies from patients with alcoholic liver disease. Of special interest were the morphologic resemblance of certain fine structural variations in mitochondria and crystalloid inclusions. Four types of alterations within mitochondria were found that seemed to relate to cytoplasmic crystalloids.Type 1 alteration consisted of localized groups of cristae, usually oriented in the long direction of the organelle (Fig. 1A). In this plane they appeared serrated at the periphery with blind endings in the matrix. Other sections revealed a system of equally-spaced diagonal lines lengthwise in the mitochondrion with cristae protruding from both ends (Fig. 1B). Profiles of this inclusion were not unlike tangential cuts of a crystalloid structure frequently seen in enlarged mitochondria described below.

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Coherency loss in γ' precipitates in nickel-base superalloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075014 ◽

1983 ◽

Vol 41 ◽

pp. 244-245

Author(s):

R. A. Ricks ◽

Angus J. Porter

Keyword(s):

Lattice Mismatch ◽

Lattice Parameter ◽

Nickel Base Superalloy ◽

Large Size ◽

The Matrix ◽

Nimonic 80A ◽

Interfacial Dislocations ◽

Nickel Base ◽

Coherency Loss ◽

Nimonic 115

During a recent investigation concerning the growth of γ' precipitates in nickel-base superalloys it was observed that the sign of the lattice mismatch between the coherent particles and the matrix (γ) was important in determining the ease with which matrix dislocations could be incorporated into the interface to relieve coherency strains. Thus alloys with a negative misfit (ie. the γ' lattice parameter was smaller than the matrix) could lose coherency easily and γ/γ' interfaces would exhibit regularly spaced networks of dislocations, as shown in figure 1 for the case of Nimonic 115 (misfit = -0.15%). In contrast, γ' particles in alloys with a positive misfit could grow to a large size and not show any such dislocation arrangements in the interface, thus indicating that coherency had not been lost. Figure 2 depicts a large γ' precipitate in Nimonic 80A (misfit = +0.32%) showing few interfacial dislocations.

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Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052572 ◽

1974 ◽

Vol 32 ◽

pp. 512-513

Author(s):

S. Mahajan ◽

M. R. Pinnel ◽

J. E. Bennett

Keyword(s):

Single Phase ◽

Alloy Composition ◽

Supersaturated Solid Solution ◽

Cell Formation ◽

Heat Treatments ◽

Air Cooling ◽

Iced Brine ◽

Transmission Electron ◽

The Matrix ◽

Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

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Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080407 ◽

1977 ◽

Vol 35 ◽

pp. 596-597

Author(s):

E. Keyhani

Keyword(s):

Plasma Membrane ◽

Candida Utilis ◽

Synthetic Medium ◽

Freeze Fracture ◽

Translational Diffusion ◽

Yeast Cells ◽

Distilled Water ◽

Intramembrane Particles ◽

The Matrix ◽

Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

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Electron microscopy and diffraction studies of polyimides

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074069 ◽

1983 ◽

Vol 41 ◽

pp. 28-29

Author(s):

O.C. de Hodgins ◽

K. R. Lawless ◽

R. Anderson

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Structural Features ◽

Inert Atmosphere ◽

Polyimide Films ◽

Resolution Electron ◽

The Matrix ◽

High Resolution Electron Microscope ◽

Diffraction Patterns ◽

Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

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Organisation in the Structure of the Cytoplasmic Ground Substance

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070357 ◽

1978 ◽

Vol 36 (3) ◽

pp. 627-639

Author(s):

K.R. Porter

Keyword(s):

Endoplasmic Reticulum ◽

Golgi Complex ◽

Random Distribution ◽

Ground Substance ◽

The Matrix ◽

Cell Processes ◽

Cytoplasmic Ground Substance

Most types of cells are known from their structure and overall form to possess a characteristic organization. In some instances this is evident in the non-random disposition of organelles and such system subunits as cisternae of the endoplasmic reticulum or the Golgi complex. In others it appears in the distribution and orientation of cytoplasmic fibrils. And in yet others the organization finds expression in the non-random distribution and orientation of microtubules, especially as found in highly anisometric cells and cell processes. The impression is unavoidable that in none of these cases is the organization achieved without the involvement of the cytoplasmic ground substance (CGS) or matrix. This impression is based on the fact that a matrix is present and that in all instances these formed structures, whether membranelimited or filamentous, are suspended in it. In some well-known instances, as in arrays of microtubules which make up axonemes and axostyles, the matrix resolves itself into bridges (and spokes) between the microtubules, bridges which are in some cases very regularly disposed and uniform in size (Mcintosh, 1973; Bloodgood and Miller, 1974; Warner and Satir, 1974).

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