Strongly transitive actions on euclidean buildings

We prove a decomposition result for a group G acting strongly transitively on the Tits boundary of a Euclidean building. As an application we provide a local to global result for discrete Euclidean buildings, which generalizes results in the locally compact case by Caprace–Ciobotaru and Burger–Mozes. Let X be a Euclidean building without cone factors. If a group G of automorphisms of X acts strongly transitively on the spherical building at infinity ?X, then the G-stabilizer of every affine apartment in X contains all reflections along thick walls. In particular G acts strongly transitively on X if X is simplicial and thick.     

An order-theoretic characterization of the Howard–Bachmann-hierarchy

In this article we provide an intrinsic characterization of the famous Howard–Bachmann ordinal in terms of a natural well-partial-ordering by showing that this ordinal can be realized as a maximal order type of a class of generalized trees with respect to a homeomorphic embeddability relation. We use our calculations to draw some conclusions about some corresponding subsystems of second order arithmetic. All these subsystems deal with versions of light-face \(\varPi ^1_1\)-comprehension.     

Radical CH Alkylation of BODIPY Dyes Using Potassium Trifluoroborates or Boronic Acids

A one‐step synthetic procedure for the radical C?H alkylation of BODIPY dyes has been developed. This new reaction generates alkyl radicals through the oxidation of boronic acids or potassium trifluoroborates and allows the synthesis of mono‐, di‐, tri‐, and tetraalkylated fluorophores in a good to excellent yield for a broad range of organoboron compounds. Using this protocol, multiple bulky alkyl groups can be introduced onto the BODIPY core thus creating solid‐state emissive BODIPY dyes.     

An expedient atom-efficient synthesis of the cannabinoid CB1 receptor inverse agonist ibipinabant

A novel synthetic route to the highly selective and orally active cannabinoid CB₁ receptor inverse agonist ibipinabant is described which combines the use of inexpensive, commercially available reagents and mild reaction conditions with a high degree of atom-efficiency. The method is expected to enable the rapid synthesis of a variety of sulfonylguanidines.     

Synthesis and characterization of a colloidal novel folic acid?C??-cyclodextrin conjugate for targeted drug delivery

A novel folic acid?C??-cyclodextrin (??-CD) conjugate was synthesized and preliminarily characterized by ¹H NMR, ESI-MS, and MALDI-MS. ¹H NMR shows the presence of ??- and ??-conjugates which are generated by ??-CD linkage in turn with both carboxylic functions of folic acid. Moreover ROESY evidences supramolecular interactions between the benzene ring of the folic acid and the ??-CD cavity. DOSY suggests that ethylenediamine derived ??-CD?Cfolic acid forms a colloidal dispersion difficult to purify from free folic acid. An analysis of self-diffusion coefficient (D_s) of the three species (??-, ??-conjugates, and free folic acid) and relaxation times (T₁ and T₂) is reported to tentatively explain the colloidal behaviour of the new species in an aqueous solution.     

Biofunctionalization of electrowetting-on-dielectric digital microfluidic chips for miniaturized cell-based applications

In this paper we report on the controlled biofunctionalization of the hydrophobic layer of electrowetting-on-dielectric (EWOD) based microfluidic chips with the aim to execute (adherent) cell-based assays. The biofunctionalization technique involves a dry lift-off method with an easy to remove Parylene-C mask and allows the creation of spatially controlled micropatches of biomolecules in the Teflon-AF(?) layer of the chip. Compared to conventional methods, this method (i) is fully biocompatible; and (ii) leaves the hydrophobicity of the chip surface unaffected by the fabrication process, which is a crucial feature for digital microfluidic chips. In addition, full control of the geometry and the dimensions of the micropatches is achieved, allowing cells to be arrayed as cell clusters or as single cells on the digital microfluidic chip surface. The dry Parylene-C lift-off technique proves to have great potential for precise biofunctionalization of digital microfluidic chips, and can enhance their use for heterogeneous bio-assays that are of interest in various biomedical applications.     

Immunomagnetic microbeads for screening with flow cytometry and identification with nano-liquid chromatography mass spectrometry of ochratoxins in wheat and cereal

Multi-analyte binding assays for rapid screening of food contaminants require mass spectrometric identification of compound(s) in suspect samples. An optimal combination is obtained when the same bioreagents are used in both methods; moreover, miniaturisation is important because of the high costs of bioreagents. A concept is demonstrated using superparamagnetic microbeads coated with monoclonal antibodies (Mabs) in a novel direct inhibition flow cytometric immunoassay (FCIA) plus immunoaffinity isolation prior to identification by nano-liquid chromatography–quadrupole time-of-flight-mass spectrometry (nano-LC-Q-ToF-MS). As a model system, the mycotoxin ochratoxin A (OTA) and cross-reacting mycotoxin analogues were analysed in wheat and cereal samples, after a simple extraction, using the FCIA with anti-OTA Mabs. The limit of detection for OTA was 0.15 ng/g, which is far below the lowest maximum level of 3 ng/g established by the European Union. In the immunomagnetic isolation method, a 350-times-higher amount of beads was used to trap ochratoxins from sample extracts. Following a wash step, bound ochratoxins were dissociated from the Mabs using a small volume of acidified acetonitrile/water (2/8 v/v) prior to separation plus identification with nano-LC-Q-ToF-MS. In screened suspect naturally contaminated samples, OTA and its non-chlorinated analogue ochratoxin B were successfully identified by full scan accurate mass spectrometry as a proof of concept for identification of unknown but cross-reacting emerging mycotoxins. Due to the miniaturisation and bioaffinity isolation, this concept might be applicable for the use of other and more expensive bioreagents such as transport proteins and receptors for screening and identification of known and unknown (or masked) emerging food contaminants.