Search results for "Labelling"

Efficient alkali iodide promoted 18F-fluoroethylations with 2-[18F]fluoroethyl tosylate and 1-bromo-2-[18F]fluoroethane

2003

Abstract Radiochemical 18 F-fluorination yields of several compounds using the secondary labelling precursors 2-[ 18 F]fluoroethyl tosylate ([ 18 F]FETos) and 1-bromo-2-[ 18 F]fluoroethane ([ 18 F]BFE) could be considerably enhanced by the addition of an alkali iodide. The radiochemical yield of [ 18 F]fluoroethyl choline for example could be doubled with [ 18 F]BFE and increased from 13% to ≈80% with [ 18 F]FETos. By addition of alkali iodide to the precursor, the 18 F-fluoroethylation yields of established radiopharmaceuticals, especially in the case of automated syntheses, could be significantly increased without major changes of the reaction conditions.

Is “I-DNA” derived from Nuclear DNA ?

1970

On the basis of double radioactive labelling and buoyant density studies, it is concluded that “I-DNA” is not a separate entity from nuclear DNA but may be an artefact derived from it.

GÉOCARREFOUR KEY WORDS Local level development planning, night-time, light pollution, branding, energy transition

2015

La pollution lumineuse est progressivement devenue un enjeu environnemental. Elle produit ainsi de nouveaux périmètres pour l’action publique, dans un contexte de transition énergétique incitant à modifier les pratiques d’éclairage public pour protéger la « nuit noire ». Pour les territoires de faible densité, cette vision renouvelée de la nuit constitue une « aubaine » en termes de développement territorial. Des processus différenciés de protection, de labellisation et de mise en tourisme des « ressources environnementales nocturnes » émergent, devenant ainsi un levier de la transition énergétique. For several decades, the negative impacts of artificial light on environmental mechanisms ha…

Electron microscopic immunogold cytochemistry reveals chromogranin A confined to secretory granules of porcine Merkel cells

1990

By ultrastructural immunohistochemistry using the immunogold technique, immunoreactive (ir) Chromogranin A (CGA) was found to be confined to the secretory vesicles of porcine Merkel cells. CGA was present predominantly in the periphery of the electron-dense core and on the clear halo. These findings indicate that CGA is a regular constituent of Merkel cell secretory granules but probably not exclusively responsible for their electron opacity.

Report of the Scientific Committee of the Spanish Agency for Food Safety and Nutrition (AESAN) on the assessment of olive oil by its nutritional char…

2021

* This record is given in both English and Spanish. The Nutri-Score front-of-pack nutritional labelling system uses a code of letters and colours to inform consumers about the nutritional quality of foods and drinks. However, currently this system does not cover all the positive aspects of foods that possess a specific nutritional quality within the Mediterranean diet, as in the case of olive oil and extra-virgin olive oil. The AESAN Scientific Committee has suggested different possibilities for a more accurate assessment of olive oil and especially virgin olive oil, in the Nutri-Score front-of-pack labelling system, taking into consideration those compounds that are beneficial to the consu…

Phosphonium-Boronate Amino Acid Derivatives as Fluoride Pincers for 18F-Labelling

2015

The synthesis of phosphonium-boronate amino acid derivatives was achieved by quaternization of o-boronatophenylphosphine with iodo-amino acid derivatives. Preliminary radiolabelling studies demonst...

Percepción de la seguridad alimentaria por las familias valencianas

2018

Direct radiofluorination of [18F]MH.MZ for 5-HT2A receptor molecular imaging with PET

2012

Imaging the serotonin 2A neuroreceptor with positron emission tomography has been carried out with [11C]MDL 100907 and [18F]altanserin for years. Recently, the MDL 100907 analogue [18F]MH.MZ was developed by combining the increased selectivity profile of MDL 100907 and the favourable radiophysical properties of fluorine-18. Here, we want to report the synthesis of [18F]MH.MZ via direct radiofluorination. Unfortunately, the direct radiofluorination did not have any significant benefits over the indirect labelling method. This is mainly because the precursor for the direct labelling approach is not completely stable and slowly decomposes. However, only one HPLC separation is necessary for the…

A methodical 68Ga-labelling study of DO2A-(butyl- l-tyrosine)2 with cation-exchanger post-processed 68Ga: practical aspects of radiolabelling

2011

Positron emission tomography (PET) with 68Ga is a fast-growing field in molecular imaging, both in research and in clinical routine. The availability of 68Ga via the 68Ge/68Ga radionuclide generator facilitates the development and production of radiopharmaceuticals independent of a cyclotron. The presented work shows a complete 68Ga labelling study exemplified on [68Ga]DO2A-(butyl- l-tyrosine)2, a potential tumour tracer for PET. A methodical sequence is followed to optimize the 68Ga-labelling reaction. Practical aspects are described and the different parameters contributing to the labelling yield are demonstrated. The influence of temperature, time, amount of labelling precursor and pH va…

Spatial and temporal variations in cuticle proteins as revealed by monoclonal antibodies. Immunoblotting analysis and ultrastructural immunolocalizat…

1989

A library of monoclonal antibodies (Mabs) against adult cuticle of Tenebrio was used to visualize the secretion of cuticular antigens during metamorphosis. Immunoblots of water- and urea-soluble proteins, and high resolution immunogold labelling has shown that, except in one clone, the Mabs recognize antigens in the three developmental stages. However, the MW of larval and pupal antigens are different from the adult ones, though sharing common epitopes. Blots of cuticle proteins (CPs) bound to different lectins shown few water-soluble glycosylated proteins weakly or not recognized by the Mabs, suggesting that the majority of the Mabs do not recognize glycosylated epitopes. The immunolocaliz…