Organic Phenolic Configurationally Locked Polyene Single Crystals for Electro‐optic and Terahertz Wave Applications

We investigate a configurationally locked polyene (CLP) crystal 2‐(3‐(4‐hydroxystyryl)‐5,5‐dimethylcyclohex‐2‐enylidene)malononitrile (OH1) containing a phenolic electron donor, which also acts as a hydrogen bond donor. The OH1 crystals with orthorhombic space group Pna2₁ (point group mm2) exhibit large second‐order nonlinear optical figures of merit, high thermal stability and very favorable crystal growth characteristics. Higher solubility in methanol and a larger temperature difference between the melting temperature and the decomposition temperature of OH1 compared to analogous CLP crystals, are of advantage for solution and melt crystal growth, respectively. Acentric bulk OH1 crystals of large sizes with side lengths of up to 1 cm with excellent optical quality have been successfully grown from methanol solution. The microscopic and macroscopic nonlinearities of the OH1 crystals are investigated theoretically and experimentally. The OH1 crystals exhibit a large macroscopic nonlinearity with four times larger powder second harmonic generation efficiency than that of analogous CLP crystals containing dimethylamino electron donor. A very high potential of OH1 crystals for broadband THz wave emitters in the full frequency range of 0.1–3 THz by optical rectification of 160 fs pulses has been demonstrated.     

Grout‐Verbindungen von Monopile‐Gründungsstrukturen – Trag‐ und Ermüdungsverhalten

Grouted Joint Connections of Monopile Support Structures – Structural and Fatigue Behaviour. This paper summarises the state of the art for grouted connections of support structures of Offshore Wind Energy Converters (OWECs). Results of numerical and experimental investigations of small and large scale tests of grouted joints which have been carried out within the research project “ForWind – TP V: Fatigue Assessment of Support Structures of Offshore Wind Energy Conversion Systems” at the Institute for Steel Construction, Leibniz Universität Hannover are presented. Furthermore the results of the numerical and experimental investigations are used for an exemplary calculation of a grouted joint connection of an OWEC located in the Baltic Sea. Besides the analysis of grouted joints with plain pipes the effects of an increased mechanical interlock due to shear keys on the fatigue design of grouted connections is demonstrated and fatigue classes for shear keys are presented.     

Bioinspired Design of Lysolytic Triterpenoid–Peptide Conjugates that Kill African Trypanosomes

Humans have evolved a natural immunity against Trypanosoma brucei infections, which is executed by two serum (lipo)protein complexes known as trypanolytic factors (TLF). The active TLF ingredient is the primate-specific apolipoprotein L1 (APOL1). The protein has a pore-forming activity that kills parasites by lysosomal and mitochondrial membrane fenestration. Of the many trypanosome subspecies, only two are able to counteract the activity of APOL1; this illustrates its evolutionarily optimized design and trypanocidal potency. Herein, we ask whether a synthetic (syn) TLF can be synthesized by using the design principles of the natural TLF complexes but with different chemical building blocks. We demonstrate the stepwise development of triterpenoid–peptide conjugates, in which the triterpenoids act as a cell-binding, uptake and lysosomal-transport modules and the synthetic peptide GALA acts as a pH-sensitive, pore-forming lysolytic toxin. As designed, the conjugate kills infective-stage African trypanosomes through lysosomal lysis thus demonstrating a proof-of-principle for the bioinspired, forward-design of a synTLF.     

Reactive inkjet printing of polyethylene glycol and isocyanate based inks to create porous polyurethane structures

Reactive inkjet printing offers a direct way to create polymeric structures in situ on a substrate. Therefore, two component polyurethane formulations can be utilized to be used in multicomponent inkjet printing. In this contribution, the use of polyethylene glycol (M = 200 g mol⁻¹), glycerol ethoxylate (M = 1,000 g mol⁻¹), and water (blowing agent) in combination with aliphatic 1,6-hexamethylene diisocyanate or aromatic methylene diphenyl diisocyanate for reactive inkjet printing is evaluated. The inks are jettable on a Dimatix DMP-3000 inkjet printer using a 10 pL piezo driven drop-on-demand printhead showing stable droplet formation. Solid films on glass are formed using a drop-by-drop printing strategy. Layer-by-Layer strategy gives best results on polycarbonate substrates forming porous polyurethane structures. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46977.     

Batch Tests for Optimisation of Solvent Composition and Process Flexibility of the CHALMEX FS-13 Process

ABSTRACT

Studies have been performed with the purpose of determining the optimal solvent composition of a Chalmers grouped actinide extraction (CHALMEX) solvent for the selective co-extraction of transuranic elements in a novel Grouped ActiNide EXtraction (GANEX) process. The solvent is composed of 6,6’-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo-[1,2,4]-triazin-3-yl)-[2,2’]-bipyridine (CyMe₄-BTBP) and tri-n-butyl phosphate (TBP) in phenyl trifluoromethyl sulfone (FS-13). The performance of the system has been shown to significantly depend on the ratios of the two extracting agents and the diluent to one another. Furthermore, the performance of the determined optimal solvent (10 mM CyMe₄-BTBP in 30% v/v TBP and 70% v/v FS-13) on various simulated PUREX raffinate solutions was tested. It was found that the solvent extracts all transuranic elements with high efficiency and good selectivity with regard to most other elements (fission products/activation products) present in the simulated PUREX raffinate solutions. Moreover, the solvent was found to extract a significant amount of acid. Palladium, silver, and cadmium were co-extracted along with the TRU-radionuclides, which has also been observed in other similar CHALMEX systems. The extraction of plutonium and uranium was preserved for all tested simulated PUREX raffinate solutions compared to experiments using trace amounts.     

Development and optimisation of a defined high cell density yeast medium

Saccharomyces cerevisiae cells grown in a small volume of chemically defined media neither reach the desired cell density nor grow at a fast enough rate to scale down the volume and increase the sample number of classical biochemical assays, as the detection limit of the readout often requires a high number of cells as an input. To ameliorate this problem, we developed and optimised a new high cell density (HCD) medium for S. cerevisiae. Starting from a widely used synthetic medium composition, we systematically varied the concentrations of all components without the addition of other compounds. We used response surface methodology to develop and optimise the five components of the medium: glucose, yeast nitrogen base, amino acids, monosodium glutamate, and inositol. We monitored growth, cell number, and cell size to ensure that the optimisation was towards a greater density of cells rather than just towards an increase in biomass (i.e., larger cells). Cells grown in the final medium, HCD, exhibit growth more similar to the complex medium yeast extract peptone dextrose (YPD) than to the synthetic defined (SD) medium. Whereas the final cell density of HCD prior to the diauxic shift is increased compared with YPD and SD about threefold and tenfold, respectively. We found normal cell-cycle behaviour throughout the growth phases by monitoring DNA content and protein expression using fluorescent reporters. We also ensured that HCD media could be used with a variety of strains and that they allow selection for all common yeast auxotrophic markers.     

Hypoxia-Responsive Class III Peroxidases in Maize Roots: Soluble and Membrane-Bound Isoenzymes

Flooding induces low-oxygen environments (hypoxia or anoxia) that lead to energy disruption and an imbalance of reactive oxygen species (ROS) production and scavenging enzymes in plants. The influence of hypoxia on roots of hydroponically grown maize (Zea mays L.) plants was investigated. Gene expression (RNA Seq and RT-qPCR) and proteome (LC–MS/MS and 2D-PAGE) analyses were used to determine the alterations in soluble and membrane-bound class III peroxidases under hypoxia. Gel-free peroxidase analyses of plasma membrane-bound proteins showed an increased abundance of ZmPrx03, ZmPrx24, ZmPrx81, and ZmPr85 in stressed samples. Furthermore, RT-qPCR analyses of the corresponding peroxidase genes revealed an increased expression. These peroxidases could be separated with 2D-PAGE and identified by mass spectrometry. An increased abundance of ZmPrx03 and ZmPrx85 was determined. Further peroxidases were identified in detergent-insoluble membranes. Co-regulation with a respiratory burst oxidase homolog (Rboh) and key enzymes of the phenylpropanoid pathway indicates a function of the peroxidases in membrane protection, aerenchyma formation, and cell wall remodeling under hypoxia. This hypothesis was supported by the following: (i) an elevated level of hydrogen peroxide and aerenchyma formation; (ii) an increased guaiacol peroxidase activity in membrane fractions of stressed samples, whereas a decrease was observed in soluble fractions; and (iii) alterations in lignified cells, cellulose, and suberin in root cross-sections.     

Generation of high-performance code based on a domain-specific language for algorithmic skeletons

The Journal of Supercomputing - Parallel programming can be difficult and error prone, in particular if low-level optimizations are required in order to reach high performance in complex...