National Medical Research Council Singapore, Centre for Infectious Disease Epidemiology and Research, and A*STAR Biomedical Research Council.

With respect to 2D-GRE, 3D-SE-EPI has the advantage of lower failure rate with equivalent high diagnostic performance for staging liver fibrosis in CHB/CHC patients, and thus more helpful for those challenging cases in 2D-GRE.

We located the unknown chirality–helicity equivalence in molecules with a chiral center, and as a consequence, the degeneracy of the S and R stereoisomers of lactic acid was lifted. An agreement was found with the naming schemes of S and R stereoisomers from optical experiments. This was made possible by the construction of the stress tensor trajectories in a non-Cartesian space defined by the variation of the position of the torsional bond critical point upon a structural change, along the torsion angle, θ, involving a chiral carbon atom. This was undertaken by applying a torsion θ, −180.0° ≤ θ ≤ +180.0° corresponding to clockwise and counterclockwise directions. We explain why scalar measures can at best only partially lift the degeneracy of the S and R stereoisomers, as opposed to vector-based measures that can fully lift the degeneracy. We explained the consequences for stereochemistry in terms of the ability to determine the chirality of industrially relevant reaction products.

BackgroundCopper is an important heavy metal pollutant, with strong toxicity and great harm, which is easy to accumulate in the plant body and is difficult for degradation. This paper adopts medium culture method, taking “Zheng Dan 958” maize seedlings as sample materials. With different copper ion concentration gradients for the simulation of metal copper stress on maize seedlings, it explored the effects on the membrane structure (POD activity, MDA content, membrane permeability) and root activity.ResultsPOD activity increases dramatically when the copper concentration is over 10 μmol/L. MDA content increases sharply when the copper concentration is over 1000 μmol/L, showing a rising trend. Membrane permeability increases greatly when the copper concentration is over 100 μmol/L. Root activity decreases significantly when the copper concentration is 100 μmol/L, showing a clear downward trend.ConclusionsThe copper concentration of 1000 μmol/L has exceeded the maize seedling tolerance to copper, and the activities of protective enzymes of maize seedlings are inhibited. Cell membrane lipid peroxidation has caused serious damage on the structure and function of membrane. Structure of root cells of maize seedling is also damaged, reducing the root activity, so the maize is irreversible hurt.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-014-0047-5) contains supplementary material, which is available to authorized users.

A, et al. Development and validation of a one-step real-time PCR assay for simultaneous detection of subtype H5, H7, and H9 avian influenza viruses.