stable isotope analysis, being used in many research areas, has also been applied in archaeology during the last three decades to address questions regarding the paleoclimatology and ancient diet, mobility and migration. despite the growing number of the application of stable isotope analysis in archaeological studies, there is a very few research in this regard in archaeology of iran. this res...

In order to quantitatively study the jasmonate biosynthetic pathway, we chemically synthesized a pair of isotope mass probes and established a labeling protocol. The pair of mass probes used in our work were ω-bromoacetonylpyridinium bromide (BPB) and d(5)-ω-bromoacetonylpyridinium bromide (d(5)-BPB), which contain carboxylic acid reactive groups, isotopically labeled groups and permanent posit...

RATIONALE Liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) is currently the most accurate and precise technique for the measurement of compound-specific stable carbon isotope ratios ((13)C/(12)C) in biological metabolites, at their natural abundance. However, until now this technique could not be applied for the analysis of nucleic acids, the building blocks of the carriers of ge...

A new method has been developed combining desolvating micronebulization with magnetic sector inductively coupled plasma mass spectrometry (ICPMS) for the analysis of all 14 stable rare earth elements (REEs) in small samples of marine particulate matter. Application is demonstrated for REEs in suspended particles from a deep ocean hydrothermal vent plume and a geological reference material. A 10...

Ticlopidine, an antiplatelet drug, undergoes extensive oxidative metabolism to form S-oxide, N-oxide, hydroxylated and dealkylated metabolites. However, metabolism of ticlopidine via conjugation has not been thoroughly investigated. In this study, multiple data acquisition and processing tools were applied to the detection and characterization of ticlopidine conjugates in rat bile. Accurate ful...

Nitrogen (N) isotope ratios ((15)N/(14)N) provide integrative constraints on the N inventory of the modern ocean. Anaerobic ammonium oxidation (anammox), which converts ammonium and nitrite to dinitrogen gas (N2) and nitrate, is an important fixed N sink in marine ecosystems. We studied the so far unknown N isotope effects of anammox in batch culture experiments. Anammox preferentially removes ...

Ozonolysis of alkenes, an important nonphotolytic source of hydroxyl (OH) radicals in the atmosphere, proceeds through unimolecular decay of Criegee intermediates. Here, we report a large kinetic isotope effect associated with the rate-limiting hydrogen-transfer step that releases OH radicals for a prototypical Criegee intermediate, CH3CHOO. IR excitation of selectively deuterated syn-CD3CHOO i...

[1] Tropical montane cloud forests are ecosystems intrinsically linked to a narrow range of geographic and meteorological conditions, making them potentially sensitive to small changes in precipitation or temperature. We investigate the potential application of stable isotope analysis to cloud forest dendroclimatology at Monteverde in Costa Rica in order to be able to extract both chronological...