Tandem mass spectra contain noisy peaks which make peak picking for peptide identification difficult. Moreover, all spectral peaks can be shifted due to systematic measurement errors. In this paper, a novel use of an isotope pattern vector (IPV) is proposed for denoising and systematic measurement error prediction. By matching the experimental IPVs with the theoretical IPVs of candidate fragmen...

Scintiscans of liver and spleen using technetium 99m sulphur colloid in 15 infants with extrahepatic biliary atresia and 11 infants with severe obstructive jaundice (7 with genetic deficiency of alpha 1-antitrypsin) showed similar hepatic size, pattern of isotope uptake, and splenic abnormality with no distinguishing features. In 37 older children with a variety of liver disorders, the scan was...

With the advent of novel mass spectrometry techniques such as Orbitrap MS, it is possible to determine the exact molecular formula of an unknown molecule solely from its isotope pattern. But for protein mass spectrometry, one is facing the problem that many peptides have exactly the same molecular formula even when ignoring the order of amino acids. In this work, we present an efficient method ...

Stable isotope analysis of human remains has been used to address long-standing debates regarding the speed and degree to which the introduction of farming transformed diet. In Europe, this debate has centered on northern and Atlantic regions with much less attention devoted to the arrival of farming across the Mediterranean. This study presents carbon and nitrogen stable isotope analyses of co...

The pattern of stable isotope signatures in a sub-sample of 67 juvenile weakfish Cynoscion regalis, captured at the mouth of the Christina River, 113 km upstream of the mouth of Delaware Bay (U.S.A) in the autumn of 2000, suggested that they resided at the location since recruitment. The possibility that young C. regalis departed from the generally characteristic life-history pattern of marine ...

after 24h no further increases were noted. Table 1 summarizes the general distribution pattern, and the extent of incorporation of 99Mo into protein in male mice after 2 days of oral administration. In a preliminary survey no sexual dimorphism was found. The duodenum had the highest degree of 99Mo incorporation and enzyme activity. Table 1 also shows the corresponding pattern for Drosophila lar...

After 2004 and 2008 (Vols. 378/2 and 390/2) this is the third issue of Analytical and Bioanalytical Chemistry to contain papers on new developments and applications in isotope ratio measurements. Whereas Klaus Heumann was guest editor for the two previous special issues, in this issue Torsten Schmidt joins him as guest editor for the first time. His involvement with this collection of papers st...

A direct structural identification, and quantitative assessment below the 50 nmol/ml level, of the full pattern of renally excreted metabolites is made possible by 13C NMR measurements of untreated urine samples when stable isotope-labelled (13C) drug analogues are administered to humans. The full potential of the new ex vivo NMR approach is exemplified by a study, for a group of volunteers, of...

Understanding the development of grassland ecosystems is critical for understanding the evolution of their associated vertebrate faunas. We focus on the central and southern portions of the Great Plains, which is the largest continuous grassland in North America and has a well-documented mammalian fossil record. Modern biomass in this region is dominated by C4 grasses, but paleontological evide...