436 research outputs found
New fullerene-C60 light-harvesting antennas for dye sensitized solar cells
Date du colloque : 06/2010</p
Fluorescence Properties of Photonic Crystals Doped with Perylenediimide
This study aims to present the fabrication of colloidal photonic crystals (PC) with increased fluorescence properties. The use of a highly fluorescent perylenediimide derivate (PDI) during the soap-free emulsion polymerization of styrene–acrylic acid resulted in monodisperse core–shell particles which allowed the fabrication of PC films. The properties of the hybrid material were studied in comparison with hybrid materials obtained by impregnation of films with chromophore solutions. In both cases an increase of the fluorescence response was observed in addition to a blue shift for the PDI core particles, proving the incorporation of the dye inside the copolymer particles
Procédé de préparation d’une couche mince à caractère photovoltaïque à hétérojonction
Cross-linkable azido C60-fullerene derivatives for efficient thermal stabilization of polymer bulk-heterojunction solar cells
International audienceOriginal [60]PCBM-inspired fullerene derivatives bearing an azidofunctional group were synthesized. By incorporating an optimizedquantity of this thermal cross-linker additive in the P3HT:[60]PCBMphotoactive layer, an impressive stabilization of the bulk-heterojunctionmorphology at its optimal photovoltaic performance wasachieved
Monomer type emission of perylenediimide derivatives doped polymer particles
This study aims to present the fabrication of colloidal photonic crystals (PCs) doped with perylenediimide (PDI) derivatives. Monodisperse PDI doped core–shell polymer particles have been obtained by employing a soap-free emulsion polymerization process of styrene and 2-hydroxyethylmethacrylate with the chromophore solubilized in the organic phase. The obtained polymer colloids allowed the fabrication of PC films that have been investigated by UV–vis and fluorescence spectroscopy. The hybrid materials have been investigated in comparison with PCs doped by the classical impregnation method. Thus, the doping using soap-free emulsion polymerization resulted in the obtaining of PDI doped core–shell polymer particles exhibiting monomer emission, whereas by employing an impregnation doping method H-type aggregates are formed
Reversible physical interaction between CdSe quantum dots and perylenediimide (PDI) aggregates in aqueous media
International audienc
Anionic polymerization by an electron transfer process from a CdSe quantum dot–perylenediimide (PDI) system
Reversible physical interactions between CdSe quantum dots (QDs) and perylenediimide (PDI) derivatives have been investigated. Original processes, dependent on the concentration of the two species, contact time, temperature and pH, were observed. The combining of the two solutions resulted in the formation of an electron transfer complex (ETC) due to the transfer of an electron from CdSe nanoparticles to PDI, followed by the formation of the final particularly stable dianion PDI2− species through another electron transfer process. The anionic species was employed for the polymerization initiation of glycidyl methacrylate (GMA). Some aspects of the anionic polymerization mechanism have been investigated
Limited role of culture conversion for decision-making in individual patient care and for advancing novel regimens to confirmatory clinical trials
Supported by the European and Developing Country Clinical Trials Partnership (grant IP.2007.32011.011) and the Global Alliance for TB Drug Development, with support from the Bill & Melinda Gates Foundation, US Agency for International Development, UK Department for International Development, Directorate-General for International Cooperation of the Netherlands, Irish Aid and Australian Department of Foreign Affairs and Trade.Background Despite recent increased clinical trials activity, no regimen has proved able to replace the standard 6-month regimen for drug-sensitive tuberculosis. Understanding the relationship between microbiological markers measured during treatment and long-term clinical outcomes is critical to evaluate their usefulness for decision-making for both individual patient care and for advancing novel regimens into time-consuming and expensive pivotal phase III trials. Methods Using data from the randomized controlled phase III trial REMoxTB, we evaluated sputum-based markers of speed of clearance of bacilli: time to smear negative status; time to culture negative status on LJ or in MGIT; daily rate of change of log10(TTP) to day 56; and smear or culture results at weeks 6, 8 or 12; as individual- and trial-level surrogate endpoints for long-term clinical outcome. Results Time to culture negative status on LJ or in MGIT, time to smear negative status and daily rate of change in log10(TTP) were each independent predictors of clinical outcome, adjusted for treatment (p <0.001). However, discrimination between low and high risk patients, as measured by the c-statistic, was modest and not much higher than the reference model adjusted for BMI, history of smoking, HIV status, cavitation, gender and MGIT TTP. Conclusions Culture conversion during treatment for tuberculosis, however measured, has only a limited role in decision-making for advancing regimens into phase III trials or in predicting the outcome of treatment for individual patients. REMoxTB ClinicalTrials.gov number: NCT00864383.Publisher PDFPeer reviewe
Limited role of culture conversion for decision-making in individual patient care and for advancing novel regimens to confirmatory clinical trials
Supported by the European and Developing Country Clinical Trials Partnership (grant IP.2007.32011.011) and the Global Alliance for TB Drug Development, with support from the Bill & Melinda Gates Foundation, US Agency for International Development, UK Department for International Development, Directorate-General for International Cooperation of the Netherlands, Irish Aid and Australian Department of Foreign Affairs and Trade.Background Despite recent increased clinical trials activity, no regimen has proved able to replace the standard 6-month regimen for drug-sensitive tuberculosis. Understanding the relationship between microbiological markers measured during treatment and long-term clinical outcomes is critical to evaluate their usefulness for decision-making for both individual patient care and for advancing novel regimens into time-consuming and expensive pivotal phase III trials. Methods Using data from the randomized controlled phase III trial REMoxTB, we evaluated sputum-based markers of speed of clearance of bacilli: time to smear negative status; time to culture negative status on LJ or in MGIT; daily rate of change of log10(TTP) to day 56; and smear or culture results at weeks 6, 8 or 12; as individual- and trial-level surrogate endpoints for long-term clinical outcome. Results Time to culture negative status on LJ or in MGIT, time to smear negative status and daily rate of change in log10(TTP) were each independent predictors of clinical outcome, adjusted for treatment (p <0.001). However, discrimination between low and high risk patients, as measured by the c-statistic, was modest and not much higher than the reference model adjusted for BMI, history of smoking, HIV status, cavitation, gender and MGIT TTP. Conclusions Culture conversion during treatment for tuberculosis, however measured, has only a limited role in decision-making for advancing regimens into phase III trials or in predicting the outcome of treatment for individual patients. REMoxTB ClinicalTrials.gov number: NCT00864383.Publisher PDFPeer reviewe
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