Two multiple-tracer tests were conducted at The Geysers to evaluate the relative properties of various gas tracers with respect to tritiated water. In this study the geographic distribution of the tracer responses in the two tests are compared. The DV-11 test, which was conducted in 1994, used the chlorofluorocarbon R-13 and SF6. The P-1 test used the newly developed hydrofluorocarbon tracers R...

Arctic biota are exposed to a complex suite of anthropogenicallysourced contaminants including mercury (Hg) and persistent organic pollutants (POPs). Levels of these contaminants are determined by source emissions and pathways as well biological and ecological factors. As the use of chemical tracers in trophic ecology matures and gains recognition, these tracers have increasingly been applied t...

Changes in the microdialysis outflow-to-inflow (O/I) ratio for [(14)C]ethanol and (3)H(2)O were determined in the perfused rat hindlimb after increases and decreases in nutritive flow mediated by the vasoconstrictors norepinephrine (NE) and serotonin (5-HT), respectively. Microdialysis probes (containing 10 mM [(14)C]ethanol and (3)H(2)O pumped at 1 or 2 microl/min) were inserted through the ca...

Vascular endothelial growth factor A (VEGF) acts via two vascular endothelial growth factor receptors VEGFR-1 and VEGFR-2 that play important and distinct roles in tumor biology. We reasoned that selective imaging of these receptors could provide unique information for diagnostics and for monitoring and optimizing responses to anti-cancer therapy, including antiangiogenic therapy. Herein, we re...

River biogeochemistry and source identification of nitrate by means of isotopic tracers in the Baltic Sea catchments M. Voss, B. Deutsch, R. Elmgren, C. Humborg, P. Kuuppo, M. Pastuszak, C. Rolff, and U. Schulte Baltic Sea Research Institute, Seestr. 15, 18119 Rostock, Germany Stockholm University, Department of System Ecology, 10691 Stockholm, Sweden Stockholm University, Department of Applied...

UNLABELLED There has been considerable interest in the development of a PET radioligand selective for the serotonin (5-hydroxytryptamine [5-HT]) transporter (SERT) that can be used to image 5-HT neurons in the living human brain. The most widely used SERT radiotracer to date, trans-1,2,3,5,6,10-beta-hexahydro-6-[4-(methylthio)phenyl[pyrrolo-[2,1-a]isoquinoline ((+)-(11)C-McN5652), has been succ...

Radiolabelled piperidine derivatives such as [(11)C]MDL 100907 and [(18)F]altanserin have played an important role in diagnosing malfunction in the serotonergic neurotransmission. A variety of novel piperidine MDL 100907 derivatives, possible to label with (18)F-fluorine, were synthesized to improve molecular imaging properties of [(11)C]MDL 100907. Their in vitro affinities to a broad spectrum...

Glioma is one of the most common brain tumors in adults. Its diagnosis and management have been determined by histological classifications. It is difficult to establish new paradigms because the pathology has matured and a great deal of knowledge has accumulated. On the other hand, we understand that there are limitations to this gold-standard because of the heterogeneity of glioma. Thus, it is...