Search results for "Roche"
showing 10 items of 2666 documents
Combined heterologies for monoclonal antibody-based immunoanalysis of fluxapyroxad
2018
Nowadays, instrumental methodologies and rapid bioanalytical techniques complement each other for the analysis of toxic chemical compounds. Fluxapyroxad was commercialized a few years ago as a fungicide and today it is being used worldwide to control a variety of pests. In the present study, the development of monoclonal antibody-based immunochemical methods for the analysis of this chemical in food samples was evaluated for the first time. Novel haptens were synthesized and protein bioconjugates were prepared. High-affinity and specific monoclonal antibodies to fluxapyroxad were generated from two haptens with alternative linker tethering sites. Haptens with linker site heterology and a st…
Automated pre-column derivatization of amines in biological samples with dansyl chloride and with or without post-column chemiluminescence formation …
1999
On-line automation of two different liquid chromatographic procedures, a pre-column derivatization system and a pre- and post-column system, in order to generate chemiluminescence is reported. Dansyl chloride (Dns-Cl) was used as a pre-column reagent to form fluorophores and bis(2,4,6-trichlorophenyl) oxalate (TCPO) and hydrogen peroxide (H2O2) as a post-column reagent to generate chemiluminescence. This procedure is based on the employment of a primary column packed with C18 material inserted in a multi-dimensional assembly for sample clean-up and derivatization with Dns-Cl. The dansyl derivatives formed are transferred and separated in a LiChrospher 100 RP18 analytical column (125 x 4 mm …
Molecular Dynamics Simulations of the Initial Adsorption Stages of Fibrinogen on Mica and Graphite Surfaces.
2015
Fibrinogen, a blood glycoprotein of vertebrates, plays an essential role in blood clotting by polymerizing into fibrin when activated. Upon adsorption on material surfaces, it also contributes to determine their biocompatibility and has been implicated in the onset of thrombosis and inflammation at medical implants. Here we present the first fully atomistic simulations of the initial stages of the adsorption process of fibrinogen on mica and graphite surfaces. The simulations reveal a weak adsorption on mica that allows frequent desorption and reorientation events. This adsorption is driven by electrostatic interactions between the protein and the silicate surface as well as the counterion …
Synthesis and Characterization of a Stable Copper(I) Complex for Radiopharmaceutical Applications
2014
A highly stable copper(I) complex was obtained starting from a copper(II) salt. This compound was characterized by a combination of several analytical techniques (UV/Vis spectroscopy, energy-dispersive X-ray spectroscopy, electrochemistry, and X-ray photoelectron spectroscopy) and was shown to present an N4Cu structure. These results were confirmed by a density functional calculations study of the binding energy and the electronic structure of model ligand and copper complexes. Preliminary tests of complexation showed a high ability of the corresponding ligand to chelate 64Cu in very diluted medium, which is of interest for developing new positron emission tomography imaging agents. The sta…
Charging a Capacitor from an External Fluctuating Potential using a Single Conical Nanopore
2015
We explore the electrical rectification of large amplitude fluctuating signals by an asymmetric nanostructure operating in aqueous solution. We show experimentally and theoretically that a load capacitor can be charged to voltages close to 1 V within a few minutes by converting zero time-average potentials of amplitudes in the range 0.5–3 V into average net currents using a single conical nanopore. This process suggests that significant energy conversion and storage from an electrically fluctuating environment is feasible with a nanoscale pore immersed in a liquid electrolyte solution, a system characteristic of bioelectronics interfaces, electrochemical cells, and nanoporous membranes.
Novel Polymorph of GaSe
2021
2D GaSe is a semiconductor belonging to the group of post-transition metal chalcogenides with great potential for advanced optoelectronic applications. The weak interlayer interaction in multilayer 2D materials allows the formation of several polymorphs. Here, the first structural observation of a new GaSe polymorph is reported, characterized by a distinct atomic configuration with a centrosymmetric monolayer (D-3d point group). The atomic structure of this new GaSe polymorph is determined by aberration-corrected scanning transmission electron microscopy. Density-functional theory calculations verify the structural stability of this polymorph. Furthermore, the band structure and Raman inten…