A novel neutral oligosaccharide chain found in polysialoglycoproteins isolated from Pacific salmon eggs. Structural studies by secondary ion mass spectrometry, proton nuclear magnetic resonance spectroscopy, and chemical methods

Biochemistry ◽  
1983 ◽  
Vol 22 (4) ◽  
pp. 959-963 ◽  
Author(s):  
Michio Shimamura ◽  
Toshiya Endo ◽  
Yasuo Inoue ◽  
Sadako Inoue
2002 ◽  
Vol 744 ◽  
Author(s):  
Matthew R. Bauer ◽  
John Tolle ◽  
A. V. G. Chizmeshya ◽  
S. Zollner ◽  
J. Menendez ◽  
...  

ABSTRACTThe synthesis and optical properties of a new class of Si-based infrared semiconductors in the Ge1-x Snx system are described. Chemical methods based on deuterium-stabilized Sn hydrides and UHV-CVD were used to prepare a wide range of metastable compositions and structures directly on silicon. These materials exhibit high thermal stability, superior crystallinity, and unique crystallographic and optical properties, such as adjustable band gaps and lattice constants. These properties are characterized by Rutherford backscattering, low-energy secondary ion mass spectrometry, high-resolution transmission electron microscopy, x-ray diffraction as well as infrared and Raman spectroscopies and spectroscopic ellipsometry. The films grow essentially strain free and display a strong compositional dependence of the band structure.


Holzforschung ◽  
2017 ◽  
Vol 71 (12) ◽  
pp. 969-976
Author(s):  
Peiming Zheng ◽  
Sachie Yagami ◽  
Dan Aoki ◽  
Masato Yoshida ◽  
Yuzou Sano ◽  
...  

AbstractAn occluding substance (gum) was observed in the vessels ofPhellodendron amurenseRupr. and analysed by spectroscopic and chemical methods. Following safranin-alcian blue staining, the gum in sapwood (sW) turned to blue and in heartwood (hW) to red. The gum was studiedin situby UV and Raman microscopies, time-of-flight secondary ion mass spectrometry (TOF-SIMS). The gum was isolated by laser microdissection (LMD) and it was alkali hydrolysed and the degradation products were analysed by GC-MS. The staining experiments, and the UV and Raman microscopies indicated that the major component of the sW gum is constituted of polysaccharides, while in the hW gum the aromatic character is dominating. TOF-SIMS measurements were interpreted as showing the aromatic substances in the hW gum did not contain lignin. The GC-MS analysis revealed the presence of vanillic acid in the degradation products of hW gum.


Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
Y. L. Wang

We have shown the feasibility of 20 nm lateral resolution in both topographic and elemental imaging using probes of this size from a liquid metal ion source (LMIS) scanning ion microprobe (SIM). This performance, which approaches the intrinsic resolution limits of secondary ion mass spectrometry (SIMS), was attained by limiting the size of the beam defining aperture (5μm) to subtend a semiangle at the source of 0.16 mr. The ensuing probe current, in our chromatic-aberration limited optical system, was 1.6 pA with Ga+ or In+ sources. Although unique applications of such low current probes have been demonstrated,) the stringent alignment requirements which they imposed made their routine use impractical. For instance, the occasional tendency of the LMIS to shift its emission pattern caused severe misalignment problems.


Author(s):  
Philippe Fragu

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.


Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
R. Espinosa ◽  
M. M. Le Beau

We have shown previously that isotope-labelled nucleotides in human metaphase chromosomes can be detected and mapped by imaging secondary ion mass spectrometry (SIMS), using the University of Chicago high resolution scanning ion microprobe (UC SIM). These early studies, conducted with BrdU- and 14C-thymidine-labelled chromosomes via detection of the Br and 28CN- (14C14N-> labelcarrying signals, provided some evidence for the condensation of the label into banding patterns along the chromatids (SIMS bands) reminiscent of the well known Q- and G-bands obtained by conventional staining methods for optical microscopy. The potential of this technique has been greatly enhanced by the recent upgrade of the UC SIM, now coupled to a high performance magnetic sector mass spectrometer in lieu of the previous RF quadrupole mass filter. The high transmission of the new spectrometer improves the SIMS analytical sensitivity of the microprobe better than a hundredfold, overcoming most of the previous imaging limitations resulting from low count statistics.


Author(s):  
K.K. Soni ◽  
D.B. Williams ◽  
J.M. Chabala ◽  
R. Levi-Setti ◽  
D.E. Newbury

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.


Author(s):  
Bruno Schueler ◽  
Robert W. Odom

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides unique capabilities for elemental and molecular compositional analysis of a wide variety of surfaces. This relatively new technique is finding increasing applications in analyses concerned with determining the chemical composition of various polymer surfaces, identifying the composition of organic and inorganic residues on surfaces and the localization of molecular or structurally significant secondary ions signals from biological tissues. TOF-SIMS analyses are typically performed under low primary ion dose (static SIMS) conditions and hence the secondary ions formed often contain significant structural information.This paper will present an overview of current TOF-SIMS instrumentation with particular emphasis on the stigmatic imaging ion microscope developed in the authors’ laboratory. This discussion will be followed by a presentation of several useful applications of the technique for the characterization of polymer surfaces and biological tissues specimens. Particular attention in these applications will focus on how the analytical problem impacts the performance requirements of the mass spectrometer and vice-versa.


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