The oxygen isotope fractionation scenario, which has been developed to explain the anomaly in solar system materials, predicts that CO gas is depleted 18O protoplanetary disks, where segregation between solids and inside disks had already occurred. Based on ALMA observations, we report first detection of HC18O+(4-3) a Class II disk (TW Hya). This allows us explore TW Hya from optically thin HCO...

Kinetic isotope effects related to the breaking of chemical bonds drive sulfur isotope fractionation during dissimilatory sulfate reduction (DSR), whereas oxygen isotope fractionation duringDSR is dominated by exchange between intercellular sulfur intermediates and water. We use a simplified biochemical model for DSR to explore how a kinetic oxygen isotope effect may be expressed. We then explo...

the upper cretaceous carbonate sequence of ab-deraz formation is well exposed in the kopet- dagh basin. this formation comprises marly limestone and three chalky limestone units. chalky limestone of ab-deraz formation is mainly composed of calcareous dinoflagellate (pithonellid calcispher), cocolithofore and planktonic foraminifera. carbon and oxygen stable isotopes analysis of the third chalky...

We further developed the stable isotope probing, magnetic-bead capture method to make it applicable for linking microbial community function to phylogeny at the class and family levels. The main improvements were a substantial decrease in the protocol blank and an approximately 10-fold increase in the detection limit by using a micro-elemental analyzer coupled to isotope ratio mass spectrometry...

There is a great need for quantitative assays in measuring proteins. Traditional sandwich immunoassays, largely considered the gold standard in quantitation, are associated with a high cost, long lead time, and are fraught with drawbacks (e.g. heterophilic antibodies, autoantibody interference, 'hook-effect').(1) An alternative technique is affinity enrichment of peptides coupled with quantitat...

Several mass spectrometry-based assays have emerged for the quantitative profiling of cellular tyrosine phosphorylation. Ideally, these methods should reveal the exact sites of tyrosine phosphorylation, be quantitative, and not be cost-prohibitive. The latter is often an issue as typically several milligrams of (stable isotope-labeled) starting protein material are required to enable the detect...

The Fe(III)-chelate of ethylenediamine-N,N'-bis(o-hydroxyphenylacetic) acid (o,oEDDHA) is generally considered as the most efficient and widespread Fe fertilizer for fruit crops and intensive horticulture. The determination of the xenobiotic chelating agent o,oEDDHA inside the plant is a key issue in the study of this fertilizer. Both the low concentrations of o,oEDDHA expected and the complexi...

Myocardial perfusion scintigraphy is an established method in cardiology for the diagnosis and evaluation of coronary artery disease (CAD). Thallium-201 and Tc-99m sestamibi myocardial perfusion imaging has been widely accepted as non-invasive diagnostic procedure for detection of CAD, risk stratification and myocardial viability assessment. But, standard Tl-201 redistribution and same day or 2...