Quantitative imaging of 33P in plant materials using 14C polymer references

Analytical and Bioanalytical Chemistry - Phosphorus (P) research still lacks techniques for rapid imaging of P use and allocation in different soil, sediment, and biological systems in a...     

Nonexistence of quantum fields associated with two-dimensional spacelike planes

It is shown that in a relativistic quantum field theory satisfying Wightman's axioms, there are no nontrivial field-like operators, or even bilinear forms, associated to a two (or less)-dimensional spacelike plane in Minkowski space. This generalizes Wightman's result that fields can not be defined as operators at a point and stands in contrast to Borchers' result that field operators can be associated with one-dimensional timelike planes.     

Bioconversion of vanillin to vanillyl alcohol in a two-phase reactor

One of the next challenges in the use of biocatalysts (enzyme or microbial cells) is the upgrading of biological reactions of oxidoreduction. The oxidoreductases need cofactors that must be regenerated. Practical experience shows that this is most readily achieved by using living cells of microorganisms. Living cells ofSaccharomyces cerevisiae are able to bioconvert vanillin to vanillyl alcohol (1). By working with a two-phase reactor (dodecanol—feeding medium) it has been possible to use higher vanillin concentrations without inhibiting the bioconversion (2).     

Structure of the Sulfoxide Synthase EgtB from the Ergothioneine Biosynthetic Pathway

The non‐heme iron enzyme EgtB catalyzes O₂‐dependent C? S bond formation between γ‐glutamyl cysteine and N‐α‐trimethyl histidine as the central step in ergothioneine biosynthesis. Both, the catalytic activity and the architecture of EgtB are distinct from known sulfur transferases or thiol dioxygenases. The crystal structure of EgtB from Mycobacterium thermoresistibile in complex with γ‐glutamyl cysteine and N‐α‐trimethyl histidine reveals that the two substrates and three histidine residues serve as ligands in an octahedral iron binding site. This active site geometry is consistent with a catalytic mechanism in which C? S bond formation is initiated by an iron(III)‐complexed thiyl radical attacking the imidazole ring of N‐α‐trimethyl histidine.     

Isoniazid@Fe2O3 Nanocontainers and Their Antibacterial Effect on Tuberculosis Mycobacteria

Isoniazid‐filled Fe₂O₃ hollow nanospheres (INH@Fe₂O₃, diameter <30 nm, 48 wt % INH‐load) are prepared for the first time and suggested for tuberculosis therapy. After dextran‐functionalization, the INH@Fe₂O₃@DEX nanocontainers show strong activity against Mycobacterium tuberculosis (M.tb.) and M.tb.‐infected macrophages. The nanocontainers can be considered as “Trojan horses” and show efficient, active uptake into both M.tb.‐infected macrophages and even into mycobacterial cells.