Search results for "PURIFICATION"
showing 10 items of 271 documents
2014
As traditional detergents might destabilize or even denature membrane proteins, amphiphilic polymers have moved into the focus of membrane-protein research in recent years. Thus far, Amphipols are the best studied amphiphilic copolymers, having a hydrophilic backbone with short hydrophobic chains. However, since stabilizing as well as destabilizing effects of the Amphipol belt on the structure of membrane proteins have been described, we systematically analyze the impact of the most commonly used Amphipol A8-35 on the structure and stability of a well-defined transmembrane protein model, the glycophorin A transmembrane helix dimer. Amphipols are not able to directly extract proteins from th…
High-resolution laser spectroscopy with the Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at CERN-ISOLDE
2016
The Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at CERN has achieved high-resolution resonance ionisation laser spectroscopy with a full width at half maximum linewidth of 20(1) MHz for 219;221Fr, and has measured isotopes as short lived as 5 ms with 214Fr. This development allows for greater precision in the study of hyperfine structures and isotope shifts, as well as a higher selectivity of singleisotope, even single-isomer, beams. These achievements are linked with the development of a new laser laboratory and new data-acquisition systems. publisher: Elsevier articletitle: High-resolution laser spectroscopy with the Collinear Resonance Ionisation Spectroscopy (CRIS) exp…
The Collinear Resonance Ionization Spectroscopy (CRIS) experimental setup at CERN-ISOLDE
2012
The CRIS setup at CERN-ISOLDE is a laser spectroscopy experiment dedicated to the high-resolution study of the spin, hyperfine structure and isotope shift of radioactive nuclei with low production rates (a few per second). It combines the Doppler-free resolution of the in-flight collinear geometry with the high detection efficiency of resonant ionisation. A recent commissioning campaign has demonstrated a 1% experimental efficiency, and as low as a 0.001% non-resonant ionisation. The current status of the experiment and its recent achievements with beams of francium isotopes are reported. The first identified systematic effects are discussed. publisher: Elsevier articletitle: The Collinear …
Regeneration of total RNA purification silica-based columns
2010
Silica-based columns are largely used in RNA purification, allowing fast extractions and good yields of high quality nucleic acid, but their major limitation is the high cost. The reuse of such columns, although desirable, is not recommended because of residual amounts of material from the previous sample trapped in the column matrix, which might be released during further purification. Thus, recycling does need previous complete removal of any detectable RNA trace, but to date no protocol which allows decontamination and reuse is available.We report a very rapid decontamination procedure, based on treatment with warm alkaline solution containing Triton X-100, which ensures no RNA carry-ove…
Biomass-based composite catalysts for catalytic wet peroxide oxidation of bisphenol A:preparation and characterization studies
2019
The wet granulation process was used to prepare new, efficient, and cost-effective granular biomass-based composite catalysts for catalytic wet peroxide oxidation (CWPO) of bisphenol A (BPA). The most stable composite granules was prepared by mixing biomass-based carbon residue (CR) with metakaolin (MK) combined with calcium oxide (CaO) or cement and a solvent (NaOH or KOH). For all the prepared composite granules, the optimized binding agents to carbon ratio was 0.3, the solvent to carbon ratio 1.2, and the agitation rate 1200 rpm. The specific surface area of the prepared catalysts was 152–205 m2/g. The composite granular catalyst (CR + MK + CaO + NaOH) had the most durable and stable str…
A multivariate approach of changes in filamentous, nitrifying and protist communities and nitrogen removal efficiencies during ozone dosage in a full…
2019
[EN] The application of low ozone dosage to minimize the problems caused by filamentous foaming was evaluated in two bioreactors of an urban wastewater treatment plant. Filamentous and nitrifying bacteria, as well as protist and metazoa, were monitored throughout a one-year period by FISH and conventional microscopy to examine the effects of ozone application on these specific groups of microorganisms. Multivariate data analysis was used to determine if the ozone dosage was a key factor determining the low carbon and nitrogen removal efficiencies observed throughout the study period, as well as to evaluate its impact on the biological communities monitored. The results of this study suggest…
Recent Exploits of the ISOLTRAP Mass Spectrometer
2013
Abstract The Penning-trap mass spectrometer ISOLTRAP, located at the isotope-separator facility ISOLDE (CERN), is presented in its current form taking into account technical developments since 2007. Three areas of developments are presented. The reference ion sources have been modified to guarantee a sufficient supply of reference ions for mass measurements and systematic studies. Different excitation schemes have been investigated for manipulation of the ion motion in the Penning trap, to enhance either the purification or measurement process. A multi-reflection time-of-flight mass separator has been implemented and can now be routinely used for purification and as a versatile tool for bea…
Optimization of coupled advanced oxidation processes and activated carbons for purification of salt water
2015
Photocatalysis, ozonation and activated carbons were investigated separately and in combination as tools for the purification of polluted salt water. Coupling different processes enables to overcome many drawbacks related to the use of the single technologies and at the same time to exploit possible synergistic effects. In this work a kinetic analysis was performed for modelling the degradation of 4-nitrophenol (4NP) as a probe pollutant molecule in synthetic seawater. Thus, the optimum synergistic conditions of the three processes acting together were determined and discussed.
Sensitivity of Measurement-Based Purification Processes to Inner Interactions
2017
The sensitivity of a repeated measurement-based purification scheme to additional undesired couplings is analyzed, focusing on the very simple and archetypical system consisting of two two-level systems interacting with a repeatedly measured one. Several regimes are considered and in the strong coupling (i.e., when the coupling constant of the undesired interaction is very large) the occurrence of a quantum Zeno effect is proven to dramatically jeopardize the efficiency of the purification process.
PIPERADE: A double Penning trap for mass separation and mass spectrometry at DESIR/SPIRAL2
2021
International audience; A double Penning trap is being commissioned at CENBG Bordeaux for the future DESIR/SPIRAL2 facility of GANIL. The setup is designed to perform both high-resolution mass separation of the ion beam for trap-assisted spectroscopy, and high-accuracy mass spectrometry of short-lived nuclides. In this paper, the technical details of the new device are described. First offline tests with the purification trap are also presented, showing a mass resolving power of about 105.