N-Acyl Chain in Ceramide and Sphingomyelin Determines Their Mixing Behavior, Phase State, and Surface Topography in Langmuir Films

2014 ◽  
Vol 118 (27) ◽  
pp. 7475-7487 ◽  
Author(s):  
Fernando G. Dupuy ◽  
Bruno Maggio
Keyword(s):  
Surface Topography ◽  
Phase State ◽  
Acyl Chain ◽  
Langmuir Films ◽  
Mixing Behavior

Effects of Molecular-Level Compositional Variability in Organic Aerosol on Phase State and Thermodynamic Mixing Behavior

2019 ◽  
Vol 53 (22) ◽  
pp. 13009-13018 ◽  
Author(s):  
Jenna C. Ditto ◽  
Taekyu Joo ◽  
Peeyush Khare ◽  
Roger Sheu ◽  
Masayuki Takeuchi ◽  
...  
Keyword(s):  
Phase State ◽  
Molecular Level ◽  
Organic Aerosol ◽  
Mixing Behavior ◽  
Compositional Variability

scholarly journals Monitoring the looping up of acyl chain labeled NBD lipids in membranes as a function of membrane phase state

2007 ◽  
Vol 1768 (5) ◽  
pp. 1258-1267 ◽  
Author(s):  
H. Raghuraman ◽  
Sandeep Shrivastava ◽  
Amitabha Chattopadhyay
Keyword(s):  
Phase State ◽  
Acyl Chain ◽  
Membrane Phase

Effect of acyl chain structure and bilayer phase state on binding and penetration of a supported lipid bilayer by HPA3

2011 ◽  
Vol 40 (4) ◽  
pp. 503-514 ◽  
Author(s):  
Daniel J. Hirst ◽  
Tzong-Hsien Lee ◽  
Marcus J. Swann ◽  
Sharon Unabia ◽  
Yoonkyung Park ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Phase State ◽  
Acyl Chain ◽  
Chain Structure ◽  
Supported Lipid Bilayer

Phase state and surface topography of palmitoyl-ceramide monolayers

2010 ◽  
Vol 163 (6) ◽  
pp. 594-600 ◽  
Author(s):  
Maria Laura Fanani ◽  
Bruno Maggio
Keyword(s):  
Surface Topography ◽  
Phase State

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Effects of Ion Beam Milling on Surface Topography

1973 ◽  
Vol 31 ◽  
pp. 84-85
Author(s):  
P.G. Pawar ◽  
P. Duhamel ◽  
G.W. Monk
Keyword(s):  
Surface Topography ◽  
Ion Beam ◽  
Solid Material ◽  
Beam Current ◽  
Atomic Mass ◽  
Micro Milling ◽  
Ion Milling ◽  
Controlled Atmospheres ◽  
Milling Operations ◽  
Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

Low-Loss Images in a Stem/Tem Microscope

1976 ◽  
Vol 34 ◽  
pp. 496-497 ◽  
Author(s):  
David C. Joy ◽  
Dennis M. Maher
Keyword(s):  
High Resolution ◽  
Surface Topography ◽  
Beam Direction ◽  
Low Loss ◽  
Specimen Holder ◽  
Glancing Angle ◽  
High Resolution Images ◽  
Set Up ◽  
Conventional Manner ◽  
Objective Type

High-resolution images of the surface topography of solid specimens can be obtained using the low-loss technique of Wells. If the specimen is placed inside a lens of the condenser/objective type, then it has been shown that the lens itself can be used to collect and filter the low-loss electrons. Since the probeforming lenses in TEM instruments fitted with scanning attachments are of this type, low-loss imaging should be possible.High-resolution, low-loss images have been obtained in a JEOL JEM 100B fitted with a scanning attachment and a thermal, fieldemission gun. No modifications were made to the instrument, but a wedge-shaped, specimen holder was made to fit the side-entry, goniometer stage. Thus the specimen is oriented initially at a glancing angle of about 30° to the beam direction. The instrument is set up in the conventional manner for STEM operation with all the lenses, including the projector, excited.

Microstructural morphology of sphingolipid dispersions as investigated by freeze-fracture EM

1995 ◽  
Vol 53 ◽  
pp. 944-945
Author(s):  
Vitthal S. Kulkarni ◽  
Wayne H. Anderson ◽  
Rhoderick E. Brown
Keyword(s):  
Acyl Chain ◽  
Biological Significance ◽  
Freeze Fracture ◽  
Fatty Acyl ◽  
Fatty Acyl Moiety ◽  
Aqueous Dispersions ◽  
Head Groups ◽  
Lipid Species ◽  
Microstructural Morphology ◽  
Layer Chromatography

The biological significance of the sphingomyelins (SM) and monoglycosylated sphingolipids like galactosylceramides (GalCer) are well documented Our recent investigation showed tubular bilayers in the aqueous dispersions of N-nervonoyl GalCer [N-(24:lΔ15,cls) GalCer] (a major fatty acyl moiety of natural GalCer). To determine the influence of lipid head groups on the resulting mesophasic morphology, we investigated microstructural self-assemblies of N-nervonoyl-SM [N-(24:1 Δ15,cls) SM; the second most abundant sphingomyelin in mammalian cell membranes], 1- palmitoyl-2-nervonoyl phosphatidylcholine [PNPC] (the lipid species with the same acyl chain configuration as in N-(24: 1) GalCer) and also compared it with egg-SM by freeze-fracture EM.Procedures for synthesizing and purifying N-(24:1) GalCer, N-(24:1) SM, and PNPC have been reported . Egg-SM was purchased from Avanti Polar Lipids, Alabaster AL. All lipids were >99% pure as checked by thin layer chromatography. Lipid dispersions were prepared by hydrating dry lipid with phosphate buffer (pH 6.6) at 80-90°C (3-5 min), vigorously vortexing (1 min) and repeating this procedure for three times prior to three freeze-thaw cycles.

A procedure for cross-sectioning materials for TEM analysis without ion milling

1990 ◽  
Vol 48 (4) ◽  
pp. 742-743
Author(s):  
J.P. Benedict ◽  
Ron Anderson ◽  
S. J. Klepeis
Keyword(s):  
Surface Topography ◽  
Milling Time ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Cleaning Operation ◽  
Tem Analysis ◽  
Platinum Silicide ◽  
Surface Alteration ◽  
Polishing Damage ◽  
Tools And Methods

Traditional specimen preparation procedures for non-biological samples, especially cross section preparation procedures, involves subjecting the specimen to ion milling for times ranging from minutes to tens of hours. Long ion milling time produces surface alteration, atomic number and rough-surface topography artifacts, and high temperatures. The introduction of new tools and methods in this laboratory improved our ability to mechanically thin specimens to a point where ion milling time was reduced to one to ten minutes. Very short ion milling times meant that ion milling was more of a cleaning operation than a thinning operation. The preferential thinning and the surface topography that still existed in briefly ion milled samples made the study of interfaces between materials such as platinum silicide and silicon difficult. These two problems can be eliminated by completely eliminating the ion milling step and mechanically polishing the sample to TEM transparency with the procedure outlined in this communication. Previous successful efforts leading to mechanically thinned specimens have shown that problems center on tool tilt control, removal of polishing damage, and specimen cleanliness.

High Resolution Low Loss Microscopy of Crystalline Surfaces

1980 ◽  
Vol 38 ◽  
pp. 162-163
Author(s):  
William Krakow ◽  
Alec N. Broers
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Surface Topography ◽  
Secondary Electron ◽  
Objective Lens ◽  
Surface Imaging ◽  
Low Loss ◽  
Fine Grained ◽  
Scanning Electron ◽  
Crystalline Surfaces

Low-loss scanning electron microscopy can be used to investigate the surface topography of solid specimens and provides enhanced image contrast over secondary electron images. A high resolution-condenser objective lens has allowed the low-loss technique to resolve separations of Au nucleii of 50Å and smaller dimensions of 25Å in samples coated with a fine grained carbon-Au-palladium layer. An estimate of the surface topography of fine grained vapor deposited materials (20 - 100Å) and the surface topography of underlying single crystal Si in the 1000 - 2000Å range has also been investigated. Surface imaging has also been performed on single crystals using diffracted electrons scattered through 10−2 rad in a conventional TEM. However, severe tilting of the specimen is required which degrades the resolution 15 to 100 fold due to image forshortening.

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