Synthesis of 2‐[18F]Fluoro‐2‐deoxyisosorbide 5‐mononitrate and Assessment of Its in vivo Biodistribution as Determined by Dynamic Positron Emission Tomography (PET)

Herein we disclose the synthesis of 2‐fluoro‐2‐deoxyisosorbide 5‐mononitrate (2F‐IS‐5MN), a fluorinated analogue of the commonly prescribed vasodilator isosorbide 5‐mononitrate (IS‐5MN). X‐ray structural data for IS‐5MN and its C2‐epimeric congener IM‐5MN are presented together with structural data for 2F‐IS‐5MN. Radioisotope labeling of 2F‐IS‐5MN has, for the first time, allowed observation of the in vivo biodistribution of this organic nitrate by means of dynamic positron emission tomography (PET) in wild‐type mice.     

Avoiding filter cake cracking: Influence of consolidation on desaturation characteristics

In cake filtration processes with an air-blowing step, cracking is an undesirable phenomenon as it leads to deterioration of the filtration process by highly increasing gas throughput. This leads to higher residual moisture if the pressure difference cannot be maintained and an increase in overall cost. Crack formation can be avoided by compacting the filter cake before desaturation. While this action will make the separation process applicable by highly reducing gas consumption, there are also potential negative effects. Compaction increases filter cake resistance and might therefore slow down desaturation kinetics. Therefore, the authors investigated how the filter cake characteristics governing desaturation change from the nonconsolidated to the consolidated state of the filter cake and compared these findings to the actual dewatering kinetics. The results showed that for the case where cracking could be oppressed, dewatering kinetics of the consolidated cake are actually faster than for the nonconsolidated cake, despite higher resistance of the consolidated cake. Thus, compaction is an appropriate action when dealing with filter cake cracking.     

Interaction of 1-allyl-3-methyl-imidazolium chloride and carbon black and its influence on carbon black filled rubbers

The interactions of the ionic liquid 1-allyl-3-methyl-imidazolium chloride (AMIMCl) with different grades of carbon black have been investigated using rheological measurements, differential scanning calorimetry and Raman spectroscopy. We could prove strong attractive interactions of AMIMCl with the carbon black surface, which result, for example, in the formation of an AMIMCl–carbon black–bucky gel and in an increased glass transition temperature of the ionic liquid in the presence of carbon black. Raman spectroscopy revealed that the AMIMCl is preferably attached to the edges of graphitic crystals at the carbon black surface, which have the highest adsorption energies. A surface treatment of different grades of carbon black with AMIMCl led to significant changes of the mechanical and electrical properties of different rubber compounds filled with carbon black, which can be attributed to a decreased filler–polymer interaction and a local plasticising effect of the AMIMCl at the carbon black surface.     

Salivary defense proteins: their network and role in innate and acquired oral immunity

There are numerous defense proteins present in the saliva. Although some of these molecules are present in rather low concentrations, their effects are additive and/or synergistic, resulting in an efficient molecular defense network of the oral cavity. Moreover, local concentrations of these proteins near the mucosal surfaces (mucosal transudate), periodontal sulcus (gingival crevicular fluid) and oral wounds and ulcers (transudate) may be much greater, and in many cases reinforced by immune and/or inflammatory reactions of the oral mucosa. Some defense proteins, like salivary immunoglobulins and salivary chaperokine HSP70/HSPAs (70 kDa heat shock proteins), are involved in both innate and acquired immunity. Cationic peptides and other defense proteins like lysozyme, bactericidal/permeability increasing protein (BPI), BPI-like proteins, PLUNC (palate lung and nasal epithelial clone) proteins, salivary amylase, cystatins, prolin-rich proteins, mucins, peroxidases, statherin and others are primarily responsible for innate immunity. In this paper, this complex system and function of the salivary defense proteins will be reviewed.     

Gold nanoparticle-based biosensors

The unique properties of gold nanoparticles have stimulated the increasing interest in the application of GNPs in interfacing biological recognition events with signal transduction and in designing biosensing devices exhibiting novel functions. The optical properties of GNPs provide wide range opportunities for construction optical biosensors. The excellent biocompatibility, conductivity, catalytic properties and high surface-to-volume ratio and high density of GNPs facilitate extensive application of GNPs in construction of electrochemical and piezoelectric biosensors with enhanced analytical performance with respect to other biosensor designs. In this article, the recent advances in construction of GNP-based optical, electrochemical and piezoelectric biosensors are reviewed, and some illustrative examples given, with a focus on the roles GNPs play in the biosensing process and the mechanism of GNPs for improving the analytical performances. Finally, the review concludes with an outline of present and future research for the real-world applications.     

Inorganic precursor peroxides for antifouling coatings

Modern antifouling coatings are generally based on cuprous oxide (Cu₂O) and organic biocides as active ingredients. Cu₂O is prone to bioaccumulation, and should therefore be replaced by more environmentally benign compounds when technically possible. However, cuprous oxide does not only provide antifouling properties, it is also a vital ingredient for the antifouling coating to obtain its polishing and leaching mechanism. In this paper, peroxides of strontium, calcium, magnesium, and zinc are tested as pigments in antifouling coatings. The peroxides react with seawater to create hydrogen peroxide and highly seawater-soluble ions of the metal. The goals have been to establish the antifouling potency of an antifouling coating that releases hydrogen peroxide as biocide, and to investigate the potential use of peroxides as water-soluble polishing and leaching pigments. The investigations have shown that it is possible to identify particulates that, when applied as pigments in antifouling coatings, will provide polishing and leaching rates comparable to those of Cu₂O-based coatings. Furthermore, the combination of polishing and hydrogen peroxide leaching by a coating based on zinc peroxide in a suitable binder matrix provides antifouling properties exceeding those of a similar coating based entirely on zinc oxide.     

Evaluation of pathways for washing soluble solids

Filter cake washing is a purification method for particulate products in liquids. This process is mostly one step of a sequence in a solid–liquid separation process. For soluble products not only the mechanical transport mechanisms in washing but also the dissolution process of the product must be considered in order to describe the washing process appropriately. An unconsidered dissolution may cause problems and often severe product loss depending on the material properties. This paper presents several methods of soluble solids washing including filter cake washing by pressure and centrifugal forces as well as moving bed washing. The advantages and drawbacks of each method are discussed to evaluate the suitability of its technical application.     

Supramolecular and nanochemistry

The following contributions describe various research activities of the Department of Chemistry, University of Basel in the area of nanochemistry and supramolecular chemistry.     

H2 rich syngas by selective CO2 removal from biomass gasification in a dual fluidized bed system — Process modelling approach

A process model of dual fluidized bed gasification is presented based on mass- and energy balances. The model further covers the evaluation of thermodynamic equilibrium states. The gasification is investigated for the special case that CaO/CaCO₃ is used as bed material allowing selective transport of CO₂ from the gasification reactor to the combustion reactor by repeated carbonation and calcination. Experimental data are used to determine the model parameters. An empirical approach towards the kinetics of fuel conversion allows prediction of process behaviour at varied fuel water content. The selective transport of CO₂ results in high H₂ contents in the produced syngas. The lower operating temperatures in the gasification reactor increase the efficiency of energy conversion. The results are in agreement with experimental data and show the thermodynamic limitations of the technology.