The regional ratio of cholesteryl palmitate to cholesteryl oleate measured by ToF-SIMS as a key parameter of atherosclerosis

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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New approaches to coupling TLC with TOF-SIMS

JPC - Journal of Planar Chromatography - Modern TLC ◽

10.1556/jpc.18.2005.1.8 ◽

2005 ◽

Vol 18 (101) ◽

pp. 44-50 ◽

Cited By ~ 11

Author(s):

Andrej Oriňák ◽

Guido Vering ◽

Heinrich Arlinghaus ◽

Jan Andersson ◽

Ladislav Halas ◽

...

Keyword(s):

New Approaches ◽

Tof Sims

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Preferential Orientation of Photochromic Gadolinium Oxyhydrides

10.26434/chemrxiv.12377690.v1 ◽

2020 ◽

Author(s):

Elbruz Murat Baba ◽

Jose Montero ◽

Dmitrii Moldarev ◽

Marcos V. Moro ◽

Max Wolff ◽

...

Keyword(s):

Thin Films ◽

Grain Size ◽

Rare Earth ◽

Preferential Orientation ◽

Reactive Magnetron ◽

Flow Ratio ◽

Deposition Pressure ◽

Step Process ◽

Oxidation In Air ◽

Key Parameter

We report preferential orientation control in photochromic gadolinium oxyhydride (GdHO) thin films deposited by a two-step process. Gadolinium hydride (GdH2-x) films were grown by reactive magnetron sputtering, followed by oxidation in air. The preferential orientation, grain size, anion concentrations, and photochromic response of the films are strongly dependent on the deposition pressure. GdHO films show preferential orientation along the [100] direction and exhibit photochromism when synthesized at deposition pressures up to 5.8 Pa and. The photochromic contrast is larger than 20 % when the films are deposited below 2.8 Pa with 0.22 H2/Ar flow ratio. We argue that the degree of preferential orientation defines the oxygen concentration which is known to be a key parameter for photochromism in rare-earth oxyhydride thin films. The experimental observations described above are explained by the oxidation-induced decrease of the grain size as a result of the increase of the deposition pressure of the sputtering gas.

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Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

10.26434/chemrxiv.12046125 ◽

2020 ◽

Author(s):

Feifei Jia ◽

Jie Wang ◽

Yanyan Zhang ◽

Qun Luo ◽

Luyu Qi ◽

...

Keyword(s):

Mass Spectrometry ◽

Secondary Ion Mass Spectrometry ◽

Single Cells ◽

Time Of Flight ◽

E Coli ◽

Tof Sims ◽

Ion Mass Spectrometry ◽

Chemical Tags ◽

Secondary Ion

In situ visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for in situ visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.

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Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

10.26434/chemrxiv.7067669 ◽

2018 ◽

Author(s):

Marcus J. Giansiracusa ◽

Andreas Kostopoulos ◽

George F. S. Whitehead ◽

David Collison ◽

Floriana Tuna ◽

...

Keyword(s):

Relaxation Time ◽

Single Molecule ◽

Energy Barrier ◽

Thermal Relaxation ◽

Relaxation Mechanism ◽

Blocking Temperature ◽

Single Molecule Magnets ◽

Single Molecule Magnet ◽

Key Parameter

We report a six coordinate DyIII single-molecule magnet (SMM) with an energy barrier of 1110 K for thermal relaxation of magnetization. The sample shows no retention of magnetization even at 2 K and this led us to find a good correlation between the blocking temperature and the Raman relaxation regime for SMMs. The key parameter is the relaxation time (𝜏switch) at the point where the Raman relaxation mechanism becomes more important than Orbach.

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Activation energy distribution : a key parameter in basin modeling and a geochemical technique for studying maturation and organic facies

10.29118/ipa.1908.169.185 ◽

2018 ◽

Author(s):

P. Sundararaman

Keyword(s):

Activation Energy ◽

Energy Distribution ◽

Basin Modeling ◽

Organic Facies ◽

Key Parameter

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Studies on a Failure Analysis Flow of Surface Contamination, Corrosion, and Underetch on Microchip Al Bondpads in Wafer Fabrication

ISTFA 2005: Conference Proceedings from the 31st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2005p0274 ◽

2005 ◽

Author(s):

Hua Younan

Keyword(s):

Failure Analysis ◽

Galvanic Corrosion ◽

Surface Contamination ◽

Wafer Fabrication ◽

Tof Sims ◽

Corrosion Passivation

Abstract A failure analysis flow is developed for surface contamination, corrosion and underetch on microchip Al bondpads and it is applied in wafer fabrication. SEM, EDX, Auger, FTIR, XPS and TOF-SIMS are used to identify the root causes. The results from carbon related contamination, galvanic corrosion, fluorine-induced corrosion, passivation underetch and Auger bondpad monitoring will be presented. The failure analysis flow will definitely help us to select suitable methods and tools for failure analysis of Al bondpad-related issues, identify rapidly possible root causes of the failures and find the eliminating solutions at both wafer fabrication and assembly houses.

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