Supramolecular Assembly of Aminoethylene‐Lipopeptide PMO Conjugates into RNA Splice‐Switching Nanomicelles

Phosphorodiamidate morpholino oligomers (PMOs) are oligonucleotide analogs that can be used for therapeutic modulation of pre‐mRNA splicing. Similar to other classes of nucleic acid‐based therapeutics, PMOs require delivery systems for efficient transport to the intracellular target sites. Here, artificial peptides based on the oligo(ethylenamino) acid succinyl‐tetraethylenpentamine (Stp), hydrophobic modifications, and an azide group are presented, which are used for strain‐promoted azide‐alkyne cycloaddition conjugation with splice‐switching PMOs. By systematically varying the lead structure and formulation, it is determined that the type of contained fatty acid and supramolecular assembly have a critical impact on the delivery efficacy. A compound containing linolenic acid with three cis double bonds exhibits the highest splice‐switching activity and significantly increases functional protein expression in pLuc/705 reporter cells in vitro and after local administration in vivo. Structural and mechanistic studies reveal that the lipopeptide PMO conjugates form nanoparticles, which accelerate cellular uptake and that the content of unsaturated fatty acids enhances endosomal escape. In an in vitro Duchenne muscular dystrophy exon skipping model using H2K‐mdx52 dystrophic skeletal myotubes, the highly potent PMO conjugates mediate significant splice‐switching at very low nanomolar concentrations. The presented aminoethylene‐lipopeptides are thus a promising platform for the generation of PMO‐therapeutics with a favorable activity/toxicity profile.     

Contribution of the Internal and External Oxygen to the Oxidation of Microencapsulated Fish Oil

Microencapsulation aims to protect polyunsaturated fatty acids against oxidation by embedding oil droplets in a solid matrix. In such a system the internal (dissolved and entrapped) and external (in the environment) oxygen can be differentiated. The study aims to quantify the impact of both oxygen sources on the oxidation of microencapsulated fish oil. The impact of the solubilized oxygen in bulk fish oil is investigated by saturating the oil with nitrogen, synthetic air, and pure oxygen. Even though more dissolved oxygen results in more oxidation products, the difference between the oxidation of the nitrogen and air saturated oil is significant but low. For encapsulated fish oil powders, the internal oxygen is modified by preparing oil‐in‐water emulsions under atmospheric and inert conditions. The feed is atomized and spray dried with either nitrogen or air. Powders are stored under vacuum and in vials and the hydroperoxides and anisidine value are determined in the total‐ and encapsulated oil. The internal oxygen has a minor impact, whereas the external oxygen is the main determinant for autoxidation. Apart from oxidizing the non‐encapsulated oil, the external O₂ penetrates into the particle and reacts with the encapsulated oil. Practical Applications: Comparing the contribution of the internal and external oxygen to the oxidative stability shows that the internal O₂ plays a minor role and can be neglected. This means that the emulsion preparation as well as the spray drying process can be conducted under ambient conditions. An inert production is not extending the shelf life significantly as long as the external O₂ determines oxidation. The focus should be on optimizing the diffusion barrier properties of the wall matrix to reduce the penetration of the external oxygen into the particle system. Alternatively, packaging solution reducing the external O₂ will extend the shelf life of the microencapsulated oil.     

Acoustic Properties of Amorphous Solids at Very Low Temperatures: The Quest for Interacting Tunneling States

We discuss the strain dependence of the acoustic properties of amorphous metals in both normal and superconducting states, in the temperature range 0.1 mK<T<1 K. A crossover is found when the strain energy is of the order of the effective interaction energy between tunneling systems at the corresponding temperature. Our results provide clear evidence for the interaction between tunneling systems, whose energy is in quantitative agreement with theoretical expectations, and reveal that without the knowledge of the corresponding strain dependences, the measured temperature dependences below ～50 mK of the acoustic properties of disordered solids are rather meaningless.     

Determination of the uranium enrichment with the NaIGEM code

The traditional method used to non-destructively determine the uranium enrichment with an NaI detector is based on the “enrichment meter principle” (Progress report LA-4605-MS, Los Alamos National Laboratory, NNM, 1970, p. 19), which involves measuring the intensity of the 186 keV line of ²³⁵U by selecting two regions of interest for the peak and the background. This type of method suffers from several limitations, the most limiting of which are the impossibility to make wall thickness correction or to take the inference of foreign radioisotopes into account. The NaIGEM software (A guide for using NaIGEM code, version 1.5 for DOS and Windows, 2001; Nucl. Instr. and Meth. A 458 (2001) 196) was developed to overcome these limitations by calculating the 186 keV line intensity with a fitting procedure. The code was tested in different measurement conditions on the wide variety of certified samples, in particular, on reprocessed uranium and on depleted material with thick steel filters interposed between the source and the detector. The results are presented to illustrate the performance and limitations of the tested version (A guide for using NaIGEM code, version 1.5 for DOS and Windows, 2001). The general performance is good except in the case of low-enriched uranium in thick containers.     

Probability-based current dipole localization from biomagneticfields

Focal biomagnetic sources are described as pointlike current dipoles. The dipole parameters, position, and moment coordinates are commonly determined from biomagnetic data using iterative nonlinear optimization algorithms such as the Levenberg-Marquardt algorithm. However, even for single-dipole sources, mislocalizations can occur due to side minima of the cost function or due to a wrong choice of the start vector. This can be shown by introducing a cost function where the independent variables are only the position coordinates instead of position and moment coordinates. This dimensional reduction-which is also possible for multiple dipole sources-is achieved by calculating the cost function at each position with the position and data-dependent, optimum dipole moments. The authors call these dipoles with-in a least squares sense-optimum moments, locally optimal dipoles. The visualization of such a single-dipole cost function and of the iteration steps of the Levenberg-Marquardt algorithm show why mislocalizations cannot be avoided. Therefore, the authors propose an alternative noniterative localization algorithm for single-dipole sources without this drawback. It uses localization probabilities calculated by means of the locally optimal dipoles. Besides the determination of the dipole parameters, the proposed algorithm furnishes a reliable error for each localization. Its effectiveness is shown with simulated and real patient data     

Selectivity of partial hydrogenation reactions performed in a pore-through-flow catalytic membrane reactor

The selectivity of partial hydrogenation reactions of unsaturated substrates was studied in a membrane reactor operating at 323 K and 40 bar hydrogen pressure. The reactor system was constructed as a loop of a saturation vessel and a membrane module in which the reaction mixture was resaturated with hydrogen up to 100 times. In a porous membrane made from cross-linked polyacrylic acid palladium nanoparticles were incorporated as catalysts. A well-defined residence time within the membrane was achieved due to a defined pore structure of the membrane and a convective mass flow of the reaction mixture through the membrane. The selectivity for the partially hydrogenated products was investigated as a function of the pore size of the PAA membrane and was compared to commercially available catalysts. Compared to experiments with supported catalysts (Pd/C and Pd/Al₂O₃) in a slurry and a fixed bed reactor the selectivity for the desired products could be increased by 3% (1-octyne) up to 40% (geraniol).     

Keine Mautdaten für Ermittlungsverfahren

Das Autobahnmautgesetz zeichnet sich durch eine strenge Zweckbindung für die Mautdaten aus. Diese dürfen ausschlie?lich für die Zwecke des Mautgesetzes erhoben und verarbeitet werden. Diese Vorgabe hat das LG Magdeburg in einem Beschluss richtungsweisend auch für die Verbindungsdaten der GSM-Kommunikation best?tigt.