On the liquid drop model mass formulas and decay of the heaviest nuclei

The coefficients of different macro-microscopic Liquid Drop Model mass formulas have been determined by a least square fitting procedure to 2027 experimental atomic masses. A rms deviation of 0.54 MeV can be reached. The remaining differences come mainly from the determination of the shell and pairing energies. Extrapolations are compared to 161 new experimental masses and to 656 mass evaluations. The different fits lead to a surface energy coefficient of around 17-18 MeV. Finally, decay potential barriers are revisited and predictions of decay half-lives of still unknown superheavy elements are given from previously proposed analytical formulas and from extrapolated Q values

Relative influence of the adeno-associated virus (AAV) type 2 p5 element for recombinant AAV vector site-specific integration.

The p5 promoter region of the adeno-associated virus type 2 (AAV-2) rep gene has been described as essential for Rep-mediated site-specific integration (RMSSI) of plasmid sequences in human chromosome 19. We report here that insertion of a full-length or minimal p5 element between the viral inverted terminal repeats does not significantly increase RMSSI of a recombinant AAV (rAAV) vector after infection of growth-arrested or proliferating human cells. This result suggests that the p5 element may not improve RMSSI of rAAV vectors in vivo

Solid-state NMR studies of polymer-drug interactions in pharmaceutical formulations

The development of pharmaceuticals (both drugs and their formulations) requires the characterisation of the materials in their dispensed form. Solid-state NMR is particularly appropriate for studies of such system as it does not require any pre-treatment which might affect the material properties. This methodology also provides a molecular level understanding of intra- and intermolecular bonding as well as the dynamics in pharmaceutical formulations crucial for directing their physical properties, stability, bioavailability and release kinetics of a drug in a composite. Solid-state NMR spectroscopy has been used to study the drug-polymer interactions in PLGAlpeptide guest systems. Poly(lactide-co-glycolide) (PLGA) polyesters are unique biodegradable and biocompatible polymers. They are widely applied in drug delivery devices due to their tunable physical properties. In this project, PLGAs with different lactide/glycolide ratios were used as hosts for amino acids and peptide based pharmaceuticals. The dynamics in the pure polymers and the effect of processing on the local dynamics were studied via analysis of CP-kinetics, relaxation times measurements and wide-line separation (WISE). The local dynamics characterised by solid-state NMR were correlated with the bulk properties and composition of the materials. Different aminoacids and peptides were probed to assess the dynamics occurring in the complex arginine containing polypeptide. Their local organisation was derived from the analysis of crystal structures and 2D IH_13C heteronuclear correlation (HETCOR) experiments. In the formulations, the nature of the guest and its loading level have a significant effect on the dynamics of the hosts as proven by the variable temperature TIpH time measurements, CPdynamics and WISE. Whereas arginine and ARARAF have been found to increase the local mobility in PLGA, the more complex polypeptide AZD at ca. 10% wt. tends to rigidify the system. These effects were correlated with the bulk properties of the composites. The results suggested a differentiation of the affinity of glycolide or lactide units towards different guests. Finally, the two crystalline forms of a non-steroidal and anti-inflammatory drug (indomethacin) undergoing polymorphism were characterised by solid-state NMR. Assignments of the complex Be solid-state NMR spectra are presented. Amorphous solids derived from both polymorphs were also investigated. Recrystallisation of the amorphous solid derived from the stable y-polymorph was observed. This can be prevented by dispersing the amorphous drug into an amorphous PVP polymer. In this situation, the organisation and H-bonding of the drug is altered due to the interactions between the drug and the polymer

4d-inner-shell ionization of Xe+ ions and subsequent Auger decay

We have studied Xe+4d inner-shell photoionization in a direct experiment on Xe+ ions, merging an ion and a photon beam and detecting the ejected electrons with a cylindrical mirror analyzer. The measured 4d photoelectron spectrum is compared to the 4d core valence double ionization spectrum of the neutral Xe atom, obtained with a magnetic bottle spectrometer. This multicoincidence experiment gives access to the spectroscopy of the individual Xe2+4d−15p−1 states and to their respective Auger decays, which are found to present a strong selectivity. The experimental results are interpreted with the help of ab initio calculations.1\. Auflag