Chemical synthesis of phosphatidylinositol mannoside glycans from Mycobacterium tuberculosis

The efficient synthesis of phosphatidylinositol mono- to hexa-mannoside (PIM1 to PIM6) is reported. The invention relates to these phosphatidylinositol mono- to hexa-mannosides carrying a linker and a reactive functional group, e.g. the sulfhydryl group, a protein, a fluorescent probe, or a solid phase. The invention further relates to vaccines comprising the PIMs linked to a carrier protein or an antigen

Elderly people in many respects benefit from interaction with dogs

Over the course of evolution, humans and animals have entered into a close relationship. By domesticating animals, humans were able to use them to their own advantage. However, animals should not only be seen as mere providers of material value; in fact, they actually enrich humans' lives on an emotional level. The classic examples for this evolution are dogs: they are considered loyal companions, particularly for children and elderly people. This relationship between humans and animals is the subject of this research study and is examined from a gerontological perspective by employing qualitative social research methods. Conclusion: The results of the study reveal the manifold meanings that pets - in particular dogs - can and do have to the elderly. At this point, it should also be noted that there is still a strong need for further research into this topic from a gerontological perspective

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

Metallaphotoredox catalysis is a powerful and versatile synthetic platform that enables cross-couplings under mild conditions without the need for noble metals. Its growing adoption in drug discovery has translated into an increased interest in sustainable and scalable reaction conditions. Here, we report a continuous-flow approach to metallaphotoredox catalysis using a heterogeneous catalyst that combines the function of a photo- and a nickel catalyst in a single material. The catalyst is embedded in a packed-bed reactor to combine reaction and (catalyst) separation in one step. The use of a packed bed simplifies the translation of optimized batch reaction conditions to continuous flow, as the only components present in the reaction mixture are the substrate and a base. The metallaphotoredox cross-coupling of sulfinates with aryl halides was used as a model system. The catalyst was shown to be stable, with a very low decrease of the yield (≈1% per day) during a continuous experiment over seven days, and to be effective for C–O arylations when carboxylic acids are used as nucleophile instead of sulfinates

Kontinuierliche heterogene Photokatalyse in seriellen Mikro‐Batch‐Reaktoren

Abstract Solid reagents, leaching catalysts, and heterogeneous photocatalysts are commonly employed in batch processes but are ill-suited for continuous-flow chemistry. Heterogeneous catalysts for thermal reactions are typically used in packed-bed reactors, which cannot be penetrated by light and thus are not suitable for photocatalytic reactions involving solids. We demonstrate that serial micro-batch reactors (SMBRs) allow for the continuous utilization of solid materials together with liquids and gases in flow. This technology was utilized to develop selective and efficient fluorination reactions using a modified graphitic carbon nitride heterogeneous catalyst instead of costly homogeneous metal polypyridyl complexes. The merger of this inexpensive, recyclable catalyst and the SMBR approach enables sustainable and scalable photocatalysis

Detection of an optical filament in the Monogem Ring

The Monogem Ring is a huge bright soft X-ray enhancement with a diameter of ~ 25\degr. This 0.3 kpc distant structure is a peculiar Galactic supernova remnant in that it is obviously visible only in X-rays, due to its expansion into a region of extremely low ambient density: hence, practically no optical emission or a neutral HI shell was expected to be detectable. - Here we report on the discovery of a very faint arc-like nebula on a POSS II R film copy, at the south-eastern borders of the MR. Spectroscopy revealed this filament to have a very large [SII]$\lambda$ 6716+6731/Halpha ratio of up to ~ 1.8, indicating shock excitation, and a low density of N_e <100 cm^{-3}. There is no hint of [OIII] emission in the spectra. On deep wide-field direct images in Halpha and in [SII] the nebula appears as a ~ 20 arcmin long, thin (~ 1 arcmin), structured filament, stretching N-S. We believe that this filament belongs to the MR and became visible due to the interaction of the expanding remnant with a mild density increase in the interstellar medium. Only one other possible optical filament of the MR has been reported in the literature, but no spectrum was provided.Comment: 6 pages, 4 figures, of which 2 in jpeg format and degraded because of size constraints. Accepted for publication in A&

Reversible morphology-resolved chemotactic actuation and motion of Janus emulsion droplets

We report, for the first time, a chemotactic motion of emulsion droplets that can be controllably and reversibly altered. Our approach is based on using biphasic Janus emulsion droplets, where each phase responds differently to chemically induced interfacial tension gradients. By permanently breaking the symmetry of the droplets’ geometry and composition, externally evoked gradients in surfactant concentration or effectiveness induce anisotropic Marangoni-type fluid flows adjacent to each of the two different exposed interfaces. Regulation of the competitive fluid convections then enables a controllable alteration of the speed and the direction of the droplets’ chemotactic motion. Our findings provide insight into how compositional anisotropy can affect the chemotactic behavior of purely liquid-based microswimmers. This has implications for the design of smart and adaptive soft microrobots that can autonomously regulate their response to changes in their chemical environment by chemotactically moving towards or away from a certain target, such as a bacterium.<br

Immunological evaluation of synthetic glycosylphosphatidylinositol glycoconjugates as vaccine candidates against malaria

Glycosylphosphatidylinositols (GPIs) are complex glycolipids present on the surfaces of Plasmodium parasites that may act as toxins during the progression of malaria. GPIs can activate the immune system during infection and induce the formation of anti-GPI antibodies that neutralize their activity. Therefore, an anti-toxic vaccine based on GPI glycoconjugates may prevent malaria pathogenesis. To evaluate the role of three key modifications on Plasmodium GPI glycan in the activity of these glycolipids, we synthesized and investigated six structurally distinct GPI fragments from P. falciparum. The synthetic glycans were conjugated to the CRM197 carrier protein and were tested for immunogenicity and efficacy as antimalarial vaccine candidates in an experimental cerebral malaria (ECM) model using C57BL/6JRj mice. Protection may be dependent on both, the antibody and cellular immune response to GPIs, and the elicited immune response depends on the orientation of the glycan, the number of mannoses in the structure and the presence of the phosphoethanolamine and inositol units. This study provides insights into the epitopes in GPIs and contributes to the development of GPI-based anti-toxin vaccine candidates against cerebral malaria