Aggregation of bead-monolayers in flat microfluidic chambers - simulation by the model of porous media

In this paper, we for the first time simulate the process of hydrodynamic bead aggregation in a flat micro-fluidic chamber by a porous-media model in an iterative routine. This allows us to optimize the chamber design of our recently developed experimental method to form periodical monolayers from the flow of bead suspension. Periodical monolayers are advantageous for parallel assay formats since they enhance the mechanical rigidity of the aggregated pattern. This is important to avoid a spatial rearrangement along various steps of a read-out procedure which would impair the correlation between measurements. Furthermore, the monolayer formation guarantees the individual optical accessibility of all probe beads. By modelling the monolayers with porous media, we can drastically reduce the degrees of freedom in a two-phase, multi-particle problem. This way, we are able to compute stationary hydrodynamic flow patterns in the chamber. In order to simulate the complete filling process from these stationary solutions, we developed an iterative master routine which takes the transient aggregation pattern as the initial condition, then evaluates the placement of the newly introduced beads, and finally converts the points of aggregation into porous media.     

HigHighly strained InGaAs/GaAs quantum wells emitting beyond 1.2 µm

Highly strained In_xGa_1–xAs quantum wells (QWs) with GaAs barriers emitting around 1.2 µm are grown on GaAs substrates by metal organic vapour phase epitaxy (MOVPE) at low growth temperatures using conventional precursors. The effects of growth temperature, V/III ratio and growth rate on QW composition and luminescence properties are studied. The variation of indium incorporation with V/III ratio at a growth temperature of 510 °C is found to be opposite to the results reported for 700 °C. By an appropriate choice of the growth parameters, we could extend the room temperature photoluminescence (PL) wavelength of InGaAs/GaAs QWs up to about 1.24 µm which corresponds to an average indium content of 41% in the QW. The results of the growth study were applied to broad area laser diodes emitting at 1193 nm with low threshold current densities. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Discretization of asymptotic line parametrizations using hyperboloid surface patches

Two-dimensional affine A-nets in $3$ -space are quadrilateral meshes that discretize surfaces parametrized along asymptotic lines. The defining property of A-nets is planarity of vertex stars, hence elementary quadrilaterals of a generic A-net are skew. The present article deals with the extension of A-nets to differentiable surfaces, by gluing hyperboloid surface patches into the skew quadrilaterals. The obtained surfaces, named “hyperbolic nets”, are a novel, piecewise smooth discretization of surfaces parametrized along asymptotic lines. A simply connected affine A-net can be extended to a hyperbolic net if all quadrilateral strips are “equi-twisted”. The geometric condition of equi-twist implies the combinatorial property, that all inner vertices of the A-net have to be of even degree. If an A-net can be extended to a hyperbolic net, then there exists a 1-parameter family of such extensions. It is briefly explained how the generation of hyperbolic nets can be implemented on a computer. We use a projective model of Plücker line geometry in order to describe A-nets and hyperboloids.     

Antimicrobial Peptide Dendrimers and Quorum-Sensing Inhibitors in Formulating Next-Generation Anti-Infection Cell Therapy Dressings for Burns

Multidrug resistance infections are the main cause of failure in the pro-regenerative cell-mediated therapy of burn wounds. The collagen-based matrices for delivery of cells could be potential substrates to support bacterial growth and subsequent lysis of the collagen leading to a cell therapy loss. In this article, we report the development of a new generation of cell therapy formulations with the capacity to resist infections through the bactericidal effect of antimicrobial peptide dendrimers and the anti-virulence effect of anti-quorum sensing MvfR (PqsR) system compounds, which are incorporated into their formulation. Anti-quorum sensing compounds limit the pathogenicity and antibiotic tolerance of pathogenic bacteria involved in the burn wound infections, by inhibiting their virulence pathways. For the first time, we report a biological cell therapy dressing incorporating live progenitor cells, antimicrobial peptide dendrimers, and anti-MvfR compounds, which exhibit bactericidal and anti-virulence properties without compromising the viability of the progenitor cells.     

A survey of phosphors novel for thermography

With regard to phosphor thermometry, seven luminescent ceramic materials were synthesised and characterised, namely CaMoO₄:Eu³⁺, CaTiO₃:Pr³⁺, LaPO₄:Eu³⁺, LaVO₄:Eu³⁺, LiAl₅O₈:Fe³⁺, TiMg₂O₄:Mn⁴⁺ and ZnGa₂O₄:Mn²⁺. In this context, emission spectra and temperature lifetime characteristics are presented. Thus, a survey of phosphors novel for thermography is given in order to encourage further studies and more detailed characterisations of the respective materials.     

General Route for the Preparation of Diverse 17-Membered Macrocycles Based on RCM and Examination of the E/Z Selectivity

A convergent, general synthetic route to 17-membered macrocycles was developed to support biological evaluation and structure–activity relationship (SAR) studies during phenotypic screening for immunology targets. A series of amide coupling reactions led to a ring-closing metathesis (RCM) precursor that was cyclized using Grubbs' catalysts. It was found that the reaction formed the macrocyclic products in a 3:1 ratio of E/Z isomers. Moreover, it was shown that a number of similarly substituted RCM precursors undergo cyclization to produce the geometric E/Z isomers in roughly the same 3:1 ratio. The remarkable independence of the E/Z outcome from the substitution pattern of the RCM precursor makes this synthetic approach generally applicable. Separation of the E/Z isomers was achieved by preparative high-performance liquid chromatography and allowed biological profiling of the geometric isomers. Reactive groups in the macrocycle were utilized for late-stage modifications in the fashion of diversity-orientated synthesis (DOS), yielding analogs for SAR studies.     

Ueber die Bestimmung der Phosphors?ure

Ohne Zusammenfassung     

Real‐time image‐content‐based beamline control for smart 4D X‐ray imaging

Real‐time processing of X‐ray image data acquired at synchrotron radiation facilities allows for smart high‐speed experiments. This includes workflows covering parameterized and image‐based feedback‐driven control up to the final storage of raw and processed data. Nevertheless, there is presently no system that supports an efficient construction of such experiment workflows in a scalable way. Thus, here an architecture based on a high‐level control system that manages low‐level data acquisition, data processing and device changes is described. This system is suitable for routine as well as prototypical experiments, and provides specialized building blocks to conduct four‐dimensional in situ, in vivo and operando tomography and laminography.