Synthesis of the tricyclic core of aldingenin B by oxidative cyclo-ketalization of an alkyne-diol

The preparation and selenium-mediated cyclo-ketalization of an alkyne-diol is described as a model study for the synthesis of aldingenin B. The oxidative cyclization is a simplifying transformation for aldingenin B, as it provides a convenient method for generating the tricylic core of the natural product from a functionalized cyclohexane.     

Complex Scaling Method for Three- and Four-Body Scattering Above the Break-up Thresholds

A formalism based on the complex-scaling method is presented to solve the few particle scattering problem in configuration space using bound state techniques with trivial boundary conditions. Several applications to A = 3,4 systems are presented to demonstrate the efficiency of the method in computing elastic as well as break-up reactions with Hamiltonians including both short and long-range interaction.     

Antihydrogen formation via antiproton scattering on positronium between the $e^{-} +\bar {H}(n = 2)$ and e−+H̄(n=3)$e^{-}+\bar {H}(n = 3)$ thresholds

The charge exchange reaction \(\bar {\mathrm {p}} + \text {Ps} \rightarrow \mathrm {e}^{-} + \bar {\mathrm {H}} \), of interest for the future experiments (GBAR, AEGIS, ATRAP, ...) aiming to produce antihydrogen atoms, is investigated in the energy range between the \(\mathrm {e}^{-}+\bar {\mathrm {H}}(n = 2)\) and \(\mathrm {e}^{-}+\bar {\mathrm {H}}(n = 3)\) thresholds. An ab-initio method based on the solution of the Faddeev-Merkuriev equations is used. Special focus is put on the impact of the Feshbach resonances and the Gailitis-Damburg oscillations, appearing in the vicinity of the \(\bar {\mathrm {p}} +\text {Ps}(n = 2)\) threshold, on the \(\bar {\mathrm {H}}\) production cross section.     

Rapid identification of allergen-encoding cDNA clones by phage display and high-density arrays

We describe a high-throughput, quantitative technology for fast identification of all different clones present in selectively enriched phage surface-displayed cDNA libraries. The strategy is based on a combination of phage display and high-density arrays. To demonstrate the utility of the method cDNAs of Aspergillus fumigatus cloned into phagemid pJuFo were expressed on the tip of filamentous M13 phage and affinity-selected on solid phase-immobilized serum IgE from allergic patients. Enriched phagemid libraries were amplified in bacteria, plated and arrayed into 384-well microtitre plates by robotic colony picking. cDNA inserts were amplified by high-throughput PCR and gridded onto high-density filter membranes. Filters were iteratively probed with randomly-sequenced inserts until all clones were identified. Eighty-one different sequences encoding IgE-binding proteins likely to cover a large part of the allergen repertoire of the mould were found. This approach represents a widely applicable method for rapid high-throughput identification of all individual cDNAs present in selectively enriched libraries.     

Breakdown of the Universality in Few-Boson Systems

We present calculation of three- and four-boson observables obtained for a series of resonant phase-equivalent short-range two-boson potentials. It is found that important deviations from the universal behavior predicted by effective field theory may appear; we analyze the conditions for this phenomenon.     

Microwave-assisted benzyl-transfer reactions of commercially available 2-benzyloxy-1-methylpyridinium triflate

Benzylation of alcohols and other substrates under thermal conditions translates smoothly from conventional heating into MW-assisted organic synthesis (MAOS). Reactions times are decreased from hours to minutes while good to excellent yields are maintained. MW heating should be considered for benzylation of high-value substrates using the title reagent.     

Extraction,amplification and detection of DNA in microfluidic chip-based assays

This review covers three aspects of PCR-based microfluidic chip assays: sample preparation, target amplification, and product detection. We also discuss the challenges related to the miniaturization and integration of each assay and make a comparison between conventional and microfluidic schemes. In order to accomplish these essential assays without human intervention between individual steps, the micro-components for fluid manipulation become critical. We therefore summarize and discuss components such as microvalves (for fluid regulation), pumps (for fluid driving) and mixers (for blending fluids). By combining the above assays and microcomponents, DNA testing of multi-step bio-reactions in microfluidic chips may be achieved with minimal external control. The combination of assay schemes with the use of micro-components also leads to rapid methods for DNA testing via multi-step bioreactions. Contains 259 references. Figure

A graphical presentation of main PCR assays: DNA extraction from raw sample, target amplification by PCR and final product detection in conventional bench-top lab and miniaturized microfluidic chip.     

Emulsification of caraway essential oil in water by lecithin and β-lactoglobulin: emulsion stability and properties of the formed oil–aqueous interface

The stability and droplet size of protein and lipid stabilised emulsions of caraway essential oil as well as the amount of protein on the emulsion droplets have been investigated. The amount of added protein (β-lactoglobulin) and lipid (phosphatidylcholine from soybean (sb-PC)) were varied and the results compared with those obtained with emulsions of a purified olive oil. In general, emulsions with triglyceride oil proved to be more stable compared with those made with caraway essential oil as the dispersed phase. However, the stability of the emulsions can be improved considerably by adding sb-PC. An increase in the protein concentration also promoted emulsion stability. We will also present how ellipsometry can be used to study the adsorption of the lipid from the oil and the protein from the aqueous phase at the oil–water interface. Independently of the used concentration, close to monolayer coverage of sb-PC was observed at the caraway oil–aqueous interface. On the other hand, at the olive oil–aqueous interface, the presence of only a small amount of sb-PC lead to an exponential increase of the layer thickness with time beyond monolayer coverage. The amounts of β-lactoglobulin adsorbed at the caraway oil–aqueous interface and at the olive oil–aqueous interface were similar, corresponding roughly to a protein monolayer coverage.