Nuclear matter distribution of 56Ni measured with EXL

In the present work, the nuclear matter distribution and the RMS matter radius of 56Ni were successfully measured for the first time by exploiting elastic proton scattering. Being a doubly magic nucleus with an equal number of protons and neutrons, 56Ni is of particular physical interest. Since it is also a radioactive nucleus, the experiment has to be performed in inverse kinematics. Hence, the experiment was conducted at the ESR (Experimental Storage Ring) at the GSI Helmholtzzentrum fuer Schwerionenforschung as part of the first experimental campaign of EXL (EXotic nuclei studied in Light-ion induced reactions). The beam of 56Ni, which was produced by in-flight fragmentation of a 58Ni beam and selected by the FRagment Separator (FRS), was injected into the ESR and interacted with the internal hydrogen target. The demanding vacuum conditions of a storage ring made it necessary to develop a novel detector system. This had to be ultra-high vacuum (UHV) compatible and, at the same time, feature an energy threshold as low as possible to enable the measurement of particles scattered at low momentum transfer. To equally fulfil both conditions, a windowless detector system was developed in which the UHV is separated from an auxiliary vacuum by a silicon strip detector. In the auxiliary vacuum, additional detectors as well as other non-UHV compatible components may be placed. This way, a telescope based on silicon detectors was set up which makes the measurement of protons in an energy range starting at few hundreds of keV up to about 50 MeV possible. In the course of the present work the employed detectors were tested and further developed by extensive laboratory tests as well as in-beam experiments. The differential cross section for elastic proton scattering was deduced from the measured angular distribution of the detected recoil protons. For this, comprehensive Monte-Carlo simulations of the setup have been performed. Then, the nuclear matter distribution was extracted from the cross section with the help of the Glauber multiple-scattering theory. For this purpose, the density distribution was parametrised by a phenomenological distribution for which a symmetrised Fermi distribution and the model-independent Sum-Of-Gaussians (SOG) method was used. The latter allows to determine theory-dependent contributions to the systematic error. Eventually, the RMS matter radius of 56Ni was calculated from the matter distributions to be (3.76+-0.08) fm which is in agreement with predictions by HFB and HF+BCS calculations. The correctness of the whole method, i.e. the measurement in inverse kinematics and the applied analysis procedure, was proven in comparison to an already known nuclear matter distribution of 58Ni of which the results are in a good agreement with the literature values

3D printing of functional assemblies with integrated polymer-bonded magnets demonstrated with a prototype of a rotary blood pump

Conventional magnet manufacturing is a significant bottleneck in the development processes of products that use magnets, because every design adaption requires production steps with long lead times. Additive manufacturing of magnetic components delivers the opportunity to shift to agile and test-driven development in early prototyping stages, as well as new possibilities for complex designs. In an effort to simplify integration of magnetic components, the current work presents a method to directly print polymer-bonded hard magnets of arbitrary shape into thermoplastic parts by fused deposition modeling. This method was applied to an early prototype design of a rotary blood pump with magnetic bearing and magnetic drive coupling. Thermoplastics were compounded with 56 vol.% isotropic NdFeB powder to manufacture printable filament. With a powder loading of 56 vol.%, remanences of 350 mT and adequate mechanical flexibility for robust processability were achieved. This compound allowed us to print a prototype of a turbodynamic pump with integrated magnets in the impeller and housing in one piece on a low-cost, end-user 3D printer. Then, the magnetic components in the printed pump were fully magnetized in a pulsed Bitter coil. The pump impeller is driven by magnetic coupling to non-printed permanent magnets rotated by a brushless DC motor, resulting in a flow rate of 3 L/min at 1000 rpm. For the first time, an application of combined multi-material and magnet printing by fused deposition modeling was shown. The presented process significantly simplifies the prototyping of products that use magnets, such as rotary blood pumps, and opens the door for more complex and innovative designs. It will also help postpone the shift to conventional manufacturing methods to later phases of the development process

Nuclear matter distribution of 56Ni measured with EXL

In the present work, the nuclear matter distribution and the RMS matter radius of 56Ni were successfully measured for the first time by exploiting elastic proton scattering. Being a doubly magic nucleus with an equal number of protons and neutrons, 56Ni is of particular physical interest. Since it is also a radioactive nucleus, the experiment has to be performed in inverse kinematics. Hence, the experiment was conducted at the ESR (Experimental Storage Ring) at the GSI Helmholtzzentrum fuer Schwerionenforschung as part of the first experimental campaign of EXL (EXotic nuclei studied in Light-ion induced reactions). The beam of 56Ni, which was produced by in-flight fragmentation of a 58Ni beam and selected by the FRagment Separator (FRS), was injected into the ESR and interacted with the internal hydrogen target. The demanding vacuum conditions of a storage ring made it necessary to develop a novel detector system. This had to be ultra-high vacuum (UHV) compatible and, at the same time, feature an energy threshold as low as possible to enable the measurement of particles scattered at low momentum transfer. To equally fulfil both conditions, a windowless detector system was developed in which the UHV is separated from an auxiliary vacuum by a silicon strip detector. In the auxiliary vacuum, additional detectors as well as other non-UHV compatible components may be placed. This way, a telescope based on silicon detectors was set up which makes the measurement of protons in an energy range starting at few hundreds of keV up to about 50 MeV possible. In the course of the present work the employed detectors were tested and further developed by extensive laboratory tests as well as in-beam experiments. The differential cross section for elastic proton scattering was deduced from the measured angular distribution of the detected recoil protons. For this, comprehensive Monte-Carlo simulations of the setup have been performed. Then, the nuclear matter distribution was extracted from the cross section with the help of the Glauber multiple-scattering theory. For this purpose, the density distribution was parametrised by a phenomenological distribution for which a symmetrised Fermi distribution and the model-independent Sum-Of-Gaussians (SOG) method was used. The latter allows to determine theory-dependent contributions to the systematic error. Eventually, the RMS matter radius of 56Ni was calculated from the matter distributions to be (3.76+-0.08) fm which is in agreement with predictions by HFB and HF+BCS calculations. The correctness of the whole method, i.e. the measurement in inverse kinematics and the applied analysis procedure, was proven in comparison to an already known nuclear matter distribution of 58Ni of which the results are in a good agreement with the literature values

In Vitro Testing and Comparison of Additively Manufactured Polymer Impellers for the CentriMag Blood Pump

Additive manufacturing (AM) is an effective tool for accelerating knowledge gain in development processes, as it enables the production of complex prototypes at low cost and with short lead times. In the development of mechanical circulatory support, the use of cheap polymer-based AM techniques for prototype manufacturing allows more design variations to be tested, promoting a better understanding of the respective system and its optimization parameters. Here, we compare four commonly used AM processes for polymers with respect to manufacturing accuracy, surface roughness, and shape fidelity in an aqueous environment. Impeller replicas of the CentriMag blood pump were manufactured with each process and integrated into original pump housings. The assemblies were tested for hydraulic properties and hemolysis in reference to the commercially available pump. Computational fluid dynamic simulations were carried out to support the transfer of the results to other applications. In hydraulic testing, the deviation in pressure head and motor current of all additively manufactured replicas from the reference pump remained below 2% over the entire operating range of the pump. In contrast, significant deviations of up to 620% were observed in hemolysis testing. Only the replicas produced by stereolithography showed a nonsignificant deviation from the reference pump, which we attribute to the low surface roughness of parts manufactured thereby. The results suggest that there is a flow-dependent threshold of roughness above which a surface strongly contributes to cell lysis by promoting a hydraulically rough boundary flow

3D Printing of Functional Assemblies with Integrated Polymer-Bonded Magnets Demonstrated with a Prototype of a Rotary Blood Pump

Conventional magnet manufacturing is a significant bottleneck in the development processes of products that use magnets, because every design adaption requires production steps with long lead times. Additive manufacturing of magnetic components delivers the opportunity to shift to agile and test-driven development in early prototyping stages, as well as new possibilities for complex designs. In an effort to simplify integration of magnetic components, the current work presents a method to directly print polymer-bonded hard magnets of arbitrary shape into thermoplastic parts by fused deposition modeling. This method was applied to an early prototype design of a rotary blood pump with magnetic bearing and magnetic drive coupling. Thermoplastics were compounded with 56 vol.% isotropic NdFeB powder to manufacture printable filament. With a powder loading of 56 vol.%, remanences of 350 mT and adequate mechanical flexibility for robust processability were achieved. This compound allowed us to print a prototype of a turbodynamic pump with integrated magnets in the impeller and housing in one piece on a low-cost, end-user 3D printer. Then, the magnetic components in the printed pump were fully magnetized in a pulsed Bitter coil. The pump impeller is driven by magnetic coupling to non-printed permanent magnets rotated by a brushless DC motor, resulting in a flow rate of 3 L/min at 1000 rpm. For the first time, an application of combined multi-material and magnet printing by fused deposition modeling was shown. The presented process significantly simplifies the prototyping of products that use magnets, such as rotary blood pumps, and opens the door for more complex and innovative designs. It will also help postpone the shift to conventional manufacturing methods to later phases of the development process

A folded and functional protein domain in an amyloid-like fibril

The effect of the polypeptide environment on polyalanine-induced fibril formation was investigated with amyloidogenic fragments from PAPBN1, a nuclear protein controlling polyadenylation. Mutation-caused extensions of the natural 10 alanine sequence up to maximally 17 alanines result in fibril formation of PABPN1 and the development of the disease oculopharyngeal muscular dystrophy (OPMD). We explored the influence of fibril formation on the structure and function of a one-domain protein linked to the fibril-forming part of PABPN1. The well-characterized, stably folded, one-domain protein, cold-shock protein CspB from Bacillus subtilis, was fused either to the C terminus of the entire N-terminal domain of PABPN1 or directly to peptides consisting of 10 or 17 alanine residues. The fusion protein between the N-terminal domain of PABPN1 and CspB formed fibrils in which the structure and activity of CspB were retained. In the fibrils formed by fusions in which the polyalanine sequence was directly linked to CspB, CspB was unfolded. These results indicate that the folded conformation and the function of a protein domain can be maintained in amyloid-like fibrils, and that the distance between this domain and the fibril plays an important role

Uncritical and unbalanced coverage of synthetic biology in the Nordic press

Synthetic biology will probably have a high impact on a variety of fields, such as healthcare, environment, biofuels, agriculture, and so on. A driving theme in European research policy is the importance of maintaining public legitimacy and support. Media can influence public attitudes and are therefore an important object of study. Through qualitative content analysis, this study investigates the press coverage of synthetic biology in the major Nordic countries between 2009 and 2014. The press coverage was found to be event-driven and there were striking similarities between countries when it comes to framing, language use, and treated themes. Reporters showed a marked dependence on their sources, mainly scientists and stakeholders, who thus drives the media agenda. The media portrayal was very positive, with an optimistic look at future benefits and very little discussion of possible risks.The first two authors are the first co-authors and have contributed equally.Synthetic Biology: media portrayal and public understandin

Nuclear astrophysics with radioactive ions at FAIR

The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process β-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes