Thioguanosine Conversion Enables mRNA‐Lifetime Evaluation by RNA Sequencing Using Double Metabolic Labeling (TUC‐seq DUAL)

Temporal information about cellular RNA populations is essential to understand the functional roles of RNA. We have developed the hydrazine/NH₄Cl/OsO₄‐based conversion of 6‐thioguanosine (6sG) into A′, where A′ constitutes a 6‐hydrazino purine derivative. A′ retains the Watson–Crick base‐pair mode and is efficiently decoded as adenosine in primer extension assays and in RNA sequencing. Because 6sG is applicable to metabolic labeling of freshly synthesized RNA and because the conversion chemistry is fully compatible with the conversion of the frequently used metabolic label 4‐thiouridine (4sU) into C, the combination of both modified nucleosides in dual‐labeling setups enables high accuracy measurements of RNA decay. This approach, termed TUC‐seq DUAL, uses the two modified nucleosides in subsequent pulses and their simultaneous detection, enabling mRNA‐lifetime evaluation with unprecedented precision.     

Using Swap-Based Search Trees to obtain Solutions for Resource Constrained Project Scheduling Problems

The high level of complexity in modern construction projects causes the problem of scheduling the involved tasks under precedence and resource constraints to be a great challenge. Additionally applications on real construction sites require non linear and non continuous constraints and objective functions. In order to optimize large scale construction sites in practice, this paper proposes a new optimization approach based on creating search trees from swapping and delaying tasks. The convergence of the proposed algorithm is analyzed and its complexity is compared to other available algorithms. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Tri-criterion inverse portfolio optimization with application to socially responsible mutual funds

We present a framework for inverse optimization in a Markowitz portfolio model that is extended to include a third criterion. The third criterion causes the traditional nondominated frontier to become a surface. Until recently, it had not been possible to compute such a surface. But by using a new method that is able to generate the nondominated surfaces of tri-criterion portfolio selection problems, we are able to compute via inverse optimization the implied risk tolerances of given funds that pursue an additional objective beyond risk and return. In applying this capability to a broad sample of conventional and socially responsible (SR) mutual funds, we find that there appears to be no significant evidence that social responsibility issues, after the screening stage, are further taken into account in the asset allocation process, which is a result that is likely to be different from what many SR investors would expect.     

A broad and tunable 250- to 430-nm source for microscopy and lifetime measurements by frequency doubling of a 78-MHz-picosecond white-light laser

Broadly tunable picosecond pulses in the UV for nonlinear microscopy and lifetime measurements are not yet readily available. Complex synchronously pumped optical parametric oscillators with subsequent frequency doubling are typically used. We show that direct second harmonic generation of a visible picosecond supercontinuum source at 78 MHz renders pulses easily tunable from 250 to 430 nm. We find that an unexpectedly large numerical aperture and the use of thick crystals increase the efficiency of the frequency doubling process dramatically. The observed spectral width and efficiency are nearly two orders of magnitude larger than predicted by conventional theory. With broadband achromatic doubling, a 130 nm wide spectrum is achieved. Pulse durations of 17–35 ps are found in the UV and an average power between 1 and 70 μW. This qualifies the setup for most UV-based microscopic investigations. As first application, the fluorescence lifetime of two differing conformations of 2-(2′-hydroxyphenyl) benzothiazole is measured.     

14-Qubit entanglement: creation and coherence

We report the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits. By investigating the coherence of up to 8 ions over time, we observe a decay proportional to the square of the number of qubits. The observed decay agrees with a theoretical model which assumes a system affected by correlated, Gaussian phase noise. This model holds for the majority of current experimental systems developed towards quantum computation and quantum metrology.     

Unusual shift of a nitro group in a phenylhydrazo-β-diketone

A novel para to meta shift of a nitro group at the phenyl ring of 3-(2-hydroxy-4-nitrophenylhydrazo)pentane-2,4-dione (H(2)L(1), 1), with formation of the new 3-(2-hydroxy-3,5-dinitrophenylhydrazo)pentane-2,4-dione (H(2)L(2), 2), occurs upon nitration of 1 with an equimolar amount of NaNO(2), under basic conditions. 2 acts as a polydentate ligand for the synthesis of the polymeric potassium [K(μ(5)-HL(2))](n) (3) and monomeric nickel(II) [Ni(H(2)O)(3)(L(2))]·H(2)O (4) compounds. They have been fully characterized, including single crystal X-ray analysis, and the complexes feature metal-organic (in 3) or supramolecular (in 4) 3D networks. The topological analysis of 3 reveals a uninodal 5-connected underlying net with the point symbol of (4(6).6(4)) and a very rare 5/4/t5 topology, which had not yet been observed in coordination polymers.     

Zinc(II) ortho-hydroxyphenylhydrazo-β-diketonate complexes and their catalytic ability towards diastereoselective nitroaldol (Henry) reaction

The zinc(II) complexes with ortho-hydroxy substituted arylhydrazo-β-diketonates [Zn(2)(CH(3)OH)(2)(μ-L(1))(2)] (5), [Zn{(CH(3))(2)SO}(H(2)O)(L(2))] (6), [Zn(2)(H(2)O)(2)(μ-L(3))(2)] (7) and [Zn(H(2)O)(2)(L(4))]·H(2)O (8) were synthesized by reaction of a zinc(II) salt with the appropriate hydrazo-β-diketone, HO-2-C(6)H(4)-NHN=C{C(=O)CH(3)}(2) (H(2)L(1), 1), HO-2-O(2)N-4-C(6)H(3)-NHN=C{C(=O)CH(3)}(2) (H(2)L(2), 2), HO-2-C(6)H(4)-NHN=CC(=O)CH(2)C(CH(3))(2)CH(2)C(=O) (H(2)L(3), 3) or HO-2-O(2)N-4-C(6)H(3)-NHN=[CC(=O)CH(2)C(CH(3))(2)CH(2)C(=O) (H(2)L(4), 4). They were fully characterized, namely by X-ray diffraction analysis that disclosed the formation of extensive H-bonds leading to 1D chains (5 and 6), 2D layers (7) or 3D networks (8). The thermodynamic parameters of the Zn(II) reaction with H(2)L(2) in solution, as well as of the thermal decomposition of 1-8 were determined. Complexes 5-8 act as diastereoselective catalysts for the nitroaldol (Henry) reaction. The threo/erythro diastereoselectivity of the β-nitroalkanol products ranges from 8:1 to 1:10 with typical yields of 80-99%, depending on the catalyst and substrate used.     

Optical Sensing of Current Dynamics in Organic Light‐Emitting Devices at the Nanometer Scale

Photoluminescence quenching of single dibenzoterrylene (DBT) dye molecules in a polymeric organic light‐emitting diode was utilized to analyze the current dynamics at nanometer resolution. The quenching mechanism of single DBT molecules results from an increase in the triplet‐state population induced by charge carrier recombination on individual guest molecules. As a consequence of the long triplet‐state relaxation time, its population results in a reduced photoluminescence of the dispersed fluorescent dyes. From the decrease in photoluminescence together with photon correlation measurements, we could quantify the local current density and its time‐dependent evolution in the vicinity of the single‐molecule probe. This optical technique establishes a non‐invasive approach to map the time‐resolved current density in organic light‐emitting diodes on the nanometer scale.     

Nanoconfinement effects in energy storage materials

Nanoconfinement effects have been studied to understand and to modify thermodynamic and kinetic properties of energy storage materials and to improve their cyclic behaviour. The paper addresses various aspects in the research and development of hydrogen storage materials and batteries. Fundamental relationships and the state-of-the art in the prediction of properties and experimental observations will be outlined and structure-property-relationships will be discussed for some hydrogen storage materials. Similar nanoconfinement effects in lithium battery anode materials will be addressed.     

Comparison of different least-squares mixed finite element formulations for hyperelasticity

The main goal of this contribution is the solution of geometrically nonlinear problems using the mixed least-squares finite element method (LSFEM). An investigation of a hyperelastic material law based on logarithmic deformation measures is performed. The basis for the proposed LSFEM is a div-grad first-order system consisting of the equilibrium condition and the constitutive equation, see e.g. Cai and Starke [1]. For the interpolation of the solution variables vector-valued Raviart-Thomas functions for the approximation of the stresses and standard Lagrange polynomials for the displacements are used. In order to show the performance of the presented formulations a numerical example is investigated, where we compare the different interpolation combinations used. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)