Peptide nucleic acid (PNA) microarrays have been used for the analysis of unlabelled DNA molecules by time-of-flight secondary mass spectrometry (ToF-SIMS). PNAs were synthesised with an automated system in multi-well plates followed by the spotting full-length molecules only onto derivatised silicon surfaces using a common split-pin contact printing instrument. After DNA hybridisation, phospha...

Generalized Linear Models (GLMs) and Single Index Models (SIMs) provide powerful generalizations of linear regression, where the target variable is assumed to be a (possibly unknown) 1-dimensional function of a linear predictor. In general, these problems entail non-convex estimation procedures, and, in practice, iterative local search heuristics are often used. Kalai and Sastry (2009) recently...

We grow hydrogenated amorphous silicon-germanium alloys by the hot-wire chemical vapor deposition technique at deposition rates between 0.5 and 1.4 nanometers per second. We prepared a set of these alloys to determine the concentrations of the alloying elements as measured by various techniques. This set consists of samples throughout the range of germanium alloying from 0% (a-Si:H) to 100% (a-...

The imaging capabilities of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and MALDI-MS sample preparation methods were combined. We used this method, named matrix-enhanced (ME) SIMS, for direct molecular imaging of nervous tissue at micrometer spatial resolution. Cryosections of the cerebral ganglia of the freshwater snail Lymnaea stagnalis were placed on indium-tin-oxide (ITO)-coat...

The incorporation of ceramide in phase-separated monolayers of ternary lipid mixtures has been studied by a combination of atomic force microscopy (AFM), fluorescence, and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Replacement of a fraction of the sphingomyelin by ceramide in DOPC/SM/cholesterol monolayers leads to changes in the SM-cholesterol-rich liquid-ordered domains. AFM s...

The interest in using high vacuum-compatible time-of-flight secondary ion mass spectrometry (TOF-SIMS) detectors integrated within focused beam instruments (FIB) has increased due to the possibility of conducting correlative and/or complementary studies with other techniques such as scanning electron microscopy, energy dispersive spectroscopy (EDS), wavelength spectroscopy, backscatter diffract...

A novel operation mode for time of flight-secondary ion mass spectrometry (ToF-SIMS) is described for a TOF.SIMS 5 instrument with a Bi-ion gun. It features sub 100 nm lateral resolution, adjustable primary ion currents and the possibility to measure with high lateral resolution as well as high mass resolution. The adjustment and performance of the novel operation mode are described and compare...

This paper presents a set of data which compares the potential and limitations of laser microprobe mass spectrometry (TOFLMMS and FT-LMMS) and static secondary ion mass spectrometry (S-SIMS) for inorganic speciation at a microscopical level. In general LMMS yields prominent signals of adduct ions consisting of the intact molecule combined with a stable ion, which allows a direct identification ...