Search results for "ISOTOPE"
showing 10 items of 2232 documents
Isotopic Effect on the Kinetics of the Belousov-Zhabotinsky Reaction
2007
In this work we present results about the deuterium isotope effect on the global kinetics of a Belousov-Zhabotinsky reaction in batch conditions. A nonlinear dependence of the Induction Period upon the percentage of deuterated reactants was found. The isotopic effect on the bromination reaction of malonic acid was evaluated.
Diagnostic Performance of 68Ga-PSMA-11 Positron-emission-tomography/Computed-tomography in a Large Cohort of Patients with Biochemical Recurrence of …
2020
Gallium-68 (Ga) prostate-specific-membrane-antigen positron-emission-tomography/computed-tomography is a highly promising method for imaging primary and recurrent prostate cancer. These dual-modality imaging technologies enable whole-body functional and anatomical evaluation in a single session. This study investigated the performance of Ga-prostate-specific-membrane-antigen-11 positron-emission-tomography/computed-tomography for detecting prostate carcinoma in patients with rising prostate-specific-antigen after primary therapy. Six hundred sixty (660) patients with biochemical recurrence referred for positron-emission-tomography/computed-tomography with Ga-prostate-specific-membrane-antig…
MANOTA: a promising bifunctional chelating agent for copper-64 immunoPET
2017
International audience; Improved bifunctional chelating agents (BFC) are required for copper-64 radiolabelling of monoclonal antibodies (mAbs) under mild conditions to yield stable, target-specific imaging agents. Four different bifunctional chelating agents (BFC) were evaluated for Fab (Fragment antigen binding) conjugation and radiolabelling with copper-64. Two DOTA- (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and two NOTA- (1,4,7-triazacyclononane-1,4,7-triacetic acid) derivatives bearing a p-benzyl-isothiocyanate group were conjugated to Fab-trastuzumab - which targets the HER2/neu receptor - and the average number of chelators attached ranged from 2.4 to 4.3 macrocycles …
Synthesis of 131I-labeled glucose-conjugated inhibitors of O6-methylguanine-DNA methyltransferase (MGMT) and comparison with nonconjugated inhibitors…
2006
O 6 -Substituted guanine derivatives are powerful agents used for tumor cell sensitization by inhibition of the DNA repair enzyme O 6 -methylguanine-DNA methyltransferase (MGMT). To provide targeted accumulation of MGMT inhibitors in tumor tissue as well as tools for in vivo imaging, we synthesized iodinated C 8 -alkyl-linked glucose conjugates of 2-amino-6-(5-iodothenyl)-9H-purine (O 6 -(5-iodothenyl) guanine, ITG) and 2-amino-6-(3-iodobenzyloxy)-9H-purine (O 6 -(5-iodobenzyl) guanine, IBG). These compounds have MGMT inhibitor constants (IC 5 0 values) of 0.8 and 0.45 μM for ITGG and IBGG, respectively, as determined in HeLa S3 cells after 2-h incubation with inhibitor. To substantiate tha…
Synthesis of [11C]SSR149415 and preliminary imaging studies using positron emission tomography.
2010
Abstract SSR149415 was the first non-peptide vasopressin-(V1b) receptor antagonist reported. It has been used to probe the role of V1b receptors in animal models of depression, aggression, and stress-anxiety, and was progressed to clinical trials for the treatment of depression. Due to the interest in V1b receptors as a therapeutic target and the growing use of SSR149415 in preclinical research, we developed a method to label SSR145419 with carbon-11 and have studied its pharmacokinetics in non-human primates using positron emission tomography.
Novel heterobimetallic radiotheranostic: preparation, activity, and biodistribution.
2014
A novel Ru(II) (arene) theranostic complex is presented. It is based on a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid macrocycle bearing a triarylphosphine and can be tracked in vivo by using the γ emission of (153) Sm atoms. Notably, the heteroditopic ligand can be selectively metalated with ruthenium at the phosphorus atom despite the presence of other functionalities that are prone to metal coordination. Subsequent labeling with radionuclides such as (153) Sm can then be performed easily. The resulting heterobimetallic complex exhibits favorable solubility and stability properties in biologically relevant media. It also shows in vitro cytotoxicity in line with that expected …
Freshwater pearl mussels from northern Sweden serve as long-term, high-resolution stream water isotope recorders
2019
The stable isotope composition of lacustrine sediments is routinely used to infer Late Holocene changes in precipitation over Scandinavia and, ultimately, atmospheric circulation dynamics in the North Atlantic realm. However, such archives only provide a low temporal resolution (ca. 15 years), precluding the ability to identify changes on inter-annual and quasi-decadal timescales. Here, we present a new, high-resolution reconstruction using shells of freshwater pearl mussels, Margaritifera margaritifera, from three streams in northern Sweden. We present seasonally to annually resolved, calendar-aligned stable oxygen and carbon isotope data from 10 specimens, covering the time interval from …
Iron isotope signature of magnetofossils and oceanic biogeochemical changes through the Middle Eocene Climatic Optimum.
2021
21 pages; International audience; Magnetotactic bacteria (MTB) intracellularly precipitate magnetite (Fe3O4) crystals that can be preserved in the geological record. When MTB die, the so-called magnetofossils constitute valuable proxies for paleoenvironmental reconstructions and are suspected to represent some of the oldest traces of biomineralization on Earth. Yet, the biogenicity of putative magnetofossils found in ancient terrestrial and extra-terrestrial samples is still largely debated and their significance for past climate still holds uncertainties. Here we studied a sedimentary sequence from the Indian Ocean (ODP Hole 711A) recording the Middle Eocene Climatic Optimum (MECO) through…
Hydrogeological Behaviour and Geochemical Features of Waters in Evaporite-Bearing Low-Permeability Successions: A Case Study in Southern Sicily, Italy
2020
Knowledge about the hydrogeological behaviour of heterogeneous low-permeability media is an important tool when designing anthropogenic works (e.g., landfills) that could potentially have negative impacts on the environment and on people&rsquo
Stable Copper Isotopes: A Novel Tool to Trace Copper Behavior in Hydromorphic Soils
2010
Copper is an essential micronutrient for all organisms but may also be a pollutant. We studied the natural abundance of stable Cu isotope ratios in four soils to test whether δ 65 Cu values can be used as a tracer for biogeochemical processes in hydromorphic soils. Two of the soils were affected by stagnant water and the other two by groundwater. We determined standard soil properties and Cu partitioning into seven fractions of a sequential extraction. Copper stable isotope ratios were measured in total soil digests with multicollector inductively coupled plasma mass spectrometry. Copper concentrations in the study soils were low to average (5-34 mg kg -1 ). The variation in Cu isotope rati…