Qualitative and quantitative characterization of plasma proteins when incorporating traveling wave ion mobility into a liquid chromatography-mass spectrometry workflow for biomarker discovery: use of product ion quantitation as an alternative data analysis tool for label free quantitation.

Discovery of protein biomarkers in clinical samples necessitates significant prefractionation prior to liquid chromatography-mass spectrometry (LC-MS) analysis. Integrating traveling wave ion mobility spectrometry (TWIMS) enables in-line gas phase separation which when coupled with nanoflow liquid chromatography and data independent acquisition tandem mass spectrometry, confers significant advantages to the discovery of protein biomarkers by improving separation and inherent sensitivity. Incorporation of TWIMS leads to a packet of concentrated ions which ultimately provides a significant improvement in sensitivity.

Improving the diagnostic accuracy of N-terminal B-type natriuretic peptide in human systolic heart failure by plasma profiling using mass spectrometry.

We have combined the measurement of N-terminal pro-B type natriuretic peptide (NTproBNP) with plasma peptide profiling to evaluate the effect on sensitivity and specificity of systolic heart failure (SHF) diagnosis. Plasma NTproBNP levels were measured from 100 SHF patients and 100 age/gender matched controls and plasma protein profiles obtained using MALDI-MS. Sixty-seven m/z peaks were significantly different between SHF and normals, and following logistic regression analysis with NTproBNP values, 6 peaks retained independent predictive value.

The late X-ray afterglow of gamma-ray bursts.

We have developed a functional fit which can be used to represent the entire temporal decay of the X-ray afterglow of gamma-ray bursts (GRBs). The fit delineates and parameterizes well-defined phases for the decay: the prompt emission; an initial steep decay; a shallow plateau phase; and finally, a powerlaw afterglow. For 20% of GRBs, the plateau phase is weak, or not seen, and the initial powerlaw decay becomes the final afterglow.

Using Swift observations of prompt and afterglow emission to classify GRBs.

We present an analysis of early Burst Alert Telescope and X-ray Telescope data for 107 gamma-ray bursts (GRBs) observed by the Swift satellite. We use these data to examine the behaviour of the X-ray light curve and propose a classification scheme for GRBs based on this behaviour. As found for previous smaller samples, the earliest X-ray light curve can be well described by an exponential, which relaxes into a power-law, often with flares superimposed.

Searching for biomarkers of heart failure in the mass spectra of blood plasma.

We have developed a technique for analysing blood plasma using MALDI-MS with subsequent data analysis to identify significant and specific differences between heart failure (HF) patients and healthy individuals. A training dataset comprising 100 HF patients and 100 healthy individuals was used to search for biomarkers (m/z range 1000-10,000). EWP cartridges when used in tandem with microcon centrifugal filters were found to give the best results.