Asymmetric cellulose nanocrystals: thiolation of reducing end groups via NHS–EDC coupling

Cellulose nanocrystals (CNC) were functionalized in aqueous media at the reducing, aldehyde ends of cellulose. CNC oxidation to produce carboxyl groups was followed by carbodiimide-mediated reaction to install thiol groups. The selectivity and extent of thiolation at the reducing ends was qualitatively confirmed by imaging (transmission electron microscopy) silver nanoparticles that tagged the CNC termini and by X-ray photoelectron spectroscopy, respectively. The adsorption of thiolated CNC onto gold surfaces as well as the viscoelastic property of the formed adlayer was investigated by using quartz crystal microgravimetry. The thiolated CNC chemisorbed on the surfaces were further analyzed for surface density and distribution by using atomic force microscopy. Overall we introduce a facile, mild asymmetric thiolation procedure as an efficient alternative to conventional reductive amination.     

Conjugation of linoleic acid over a hydrogen pre-activated heterogeneous catalyst

Development of a new heterogeneous catalytic pathway for isomerization of linoleic acid to conjugated linoleic acids at mild reaction conditions over Ni/H-MCM-41 in a soluted system.     

Stability of functions in Boolean models of gene regulatory networks

Boolean networks are used to model large nonlinear systems such as gene regulatory networks. We will present results that can be used to understand how the choice of functions affects the network dynamics. The so called bias-map and its fixed points depict much of the function's dynamical role in the network. We define the concept of stabilizing functions and show that many Post and canalizing functions are also stabilizing functions. Boolean networks constructed using the same type of stabilizing functions are always stable regardless of the average in-degree of network functions. We derive the number of all stabilizing functions and find it to be much larger than the number of Post and canalizing functions. We also discuss the implementation of functions and apply the presented results to biological data that give an approximation of the distribution of regulatory functions in eucaryotic cells. We find that the obtained theoretical results on the number of active genes are biologically plausible. Finally, based on the presented results, we discuss why canalizing and Post regulatory functions seem to be common in cells.     

A modified rheometer for in-situ radial and tangential SAXS studies on shear-induced alignment

A tooth rheometer designed to investigate the influence of large amplitude oscillatory shear on the macroscopic orientation of complex fluids is described. The rheometer allows in-situ two-directional small-angle scattering measurements, making it possible to observe in particular the orientation process of hierarchically structured block copolymers in dynamics. Experiments performed with a linear poly(vinyl methyl ether) show that, despite a considerable gap/width ratio, the rheometer can be used for adequate rheological measurements. In addition we found an unexpected dependence of the dynamic parameters on the rheometer gap. The small amount of sample required favors the use of this rheometer for measuring the rheological characteristics of new compounds.     

Conformality of a quasiconformal mapping at a point

Letf be a quasiconformal mapping with the complex dilation μ. A new condition on μ is introduced for the conformality off at a pointz. The result extends the classical Teichmüller-Wittich-Belinskiî regularity theorem.     

Resumming Long-Distance Contributions to the QCD Pressure

The strict coupling constant expansion for the free energy of hot QCD plasma shows bad convergence at all reasonable temperatures, and does not agree well with its 4D lattice determination. This has recently led to various refined resummations, whereby the agreement with the lattice result should improve, at the cost of a loss of a formal agreement with the coupling constant expansion and particularly with its large infrared sensitive "long-distance" contributions. We show here how to resum the dominant long-distance effects by using a 3D effective field theory, and determine their magnitude by simple lattice Monte Carlo simulations.