The synthesis of poly(2-methyl-2-oxazoline-b-tetrahydrofurane-b-2-methyl-2-oxazoline) triblock copolymer of low molar mass has been carried out. Characterization of the purified polymer by 1H and 13C NMR spectroscopie...The synthesis of poly(2-methyl-2-oxazoline-b-tetrahydrofurane-b-2-methyl-2-oxazoline) triblock copolymer of low molar mass has been carried out. Characterization of the purified polymer by 1H and 13C NMR spectroscopies is described. These block copolymers did not give DNA containing polyplexes. The in vivo transfection properties were investigated by injection of tibialis muscles and intratracheal administration of female Swiss mice. These triblock copolymers with a molar ratio [2-methyl-2-oxazoline units]/[tetrahydrofurane units] in the 3 - 5 range gave a higher transfection efficiency than that of Lutrol or of PE6400 which are the gold standards of this transfection technique. Hydrolysis increased the performances of muscle transfection, showing the beneficial effect of the presence of positive charges, but was clearly detrimental to the transfection efficiency of pulmonary epithelium.展开更多
1 Results No doubt that one of the major breakthroughs in polymer chemistry was the discovery and the progressive implementation of the "living" and "controlled" polymerizations.These now widely us...1 Results No doubt that one of the major breakthroughs in polymer chemistry was the discovery and the progressive implementation of the "living" and "controlled" polymerizations.These now widely used techniques allow not only to control with an extreme precision the molar masses and their distributions but also to synthesise easily a broad variety of architectures from block and graft copolymers,miktoarms stars,to polymer brushes,hyperbranched polymers,dendrimers,etc....They opened an immense domain of ...展开更多
Butyltin compounds (BTs) including tributyltin (TBT) and its degradation product (DBT) and concentrations of heavy metals (Sn, Cu and Zn) were determined in mussels (Mytilus galloprovincialis) collected from some West...Butyltin compounds (BTs) including tributyltin (TBT) and its degradation product (DBT) and concentrations of heavy metals (Sn, Cu and Zn) were determined in mussels (Mytilus galloprovincialis) collected from some West Algerian harbours. BTs were detected in all the mussels. Quanti?cation of BTs and heavy metals was carried respectively by Gas Chromatography coupled with Mass Spectrometer (GC-MS) and Atomic Absorption Spectrometry, flame AAS. Concentrations of total butyltin (BTs: DBT + TBT) in mussels ranged from 0.49 to 2438 ng/g wet wt. The concentrations (μg/g wet wt) of heavy metals ranged from 0.40 to 3.55 for Sn, 9.62 to 67.03 for Cu, and 87.13 to 731.51 for Zn. Total of tin in mussels ranged from 0.2 to 1054.78 ng/g. Higher concentrations of butyltin compounds were found in mussels collected from Mers El Kebir shipyard, Arzew, a petroleum harbour (industrial), and Beni Saf fishing harbour. This suggested that maritime activities nearby the harbours play a major role as the source of BTs. Indeed, harbour of Arzew is frequented by voluminous tanker. TBT was the predominant compound in mussels collected from almost all the sampling locations;indicate the fresh input of TBT in harbours.展开更多
文摘The synthesis of poly(2-methyl-2-oxazoline-b-tetrahydrofurane-b-2-methyl-2-oxazoline) triblock copolymer of low molar mass has been carried out. Characterization of the purified polymer by 1H and 13C NMR spectroscopies is described. These block copolymers did not give DNA containing polyplexes. The in vivo transfection properties were investigated by injection of tibialis muscles and intratracheal administration of female Swiss mice. These triblock copolymers with a molar ratio [2-methyl-2-oxazoline units]/[tetrahydrofurane units] in the 3 - 5 range gave a higher transfection efficiency than that of Lutrol or of PE6400 which are the gold standards of this transfection technique. Hydrolysis increased the performances of muscle transfection, showing the beneficial effect of the presence of positive charges, but was clearly detrimental to the transfection efficiency of pulmonary epithelium.
文摘1 Results No doubt that one of the major breakthroughs in polymer chemistry was the discovery and the progressive implementation of the "living" and "controlled" polymerizations.These now widely used techniques allow not only to control with an extreme precision the molar masses and their distributions but also to synthesise easily a broad variety of architectures from block and graft copolymers,miktoarms stars,to polymer brushes,hyperbranched polymers,dendrimers,etc....They opened an immense domain of ...
文摘Butyltin compounds (BTs) including tributyltin (TBT) and its degradation product (DBT) and concentrations of heavy metals (Sn, Cu and Zn) were determined in mussels (Mytilus galloprovincialis) collected from some West Algerian harbours. BTs were detected in all the mussels. Quanti?cation of BTs and heavy metals was carried respectively by Gas Chromatography coupled with Mass Spectrometer (GC-MS) and Atomic Absorption Spectrometry, flame AAS. Concentrations of total butyltin (BTs: DBT + TBT) in mussels ranged from 0.49 to 2438 ng/g wet wt. The concentrations (μg/g wet wt) of heavy metals ranged from 0.40 to 3.55 for Sn, 9.62 to 67.03 for Cu, and 87.13 to 731.51 for Zn. Total of tin in mussels ranged from 0.2 to 1054.78 ng/g. Higher concentrations of butyltin compounds were found in mussels collected from Mers El Kebir shipyard, Arzew, a petroleum harbour (industrial), and Beni Saf fishing harbour. This suggested that maritime activities nearby the harbours play a major role as the source of BTs. Indeed, harbour of Arzew is frequented by voluminous tanker. TBT was the predominant compound in mussels collected from almost all the sampling locations;indicate the fresh input of TBT in harbours.
