Synthesis of mixed sequence borane phosphonate DNA

A novel solid-phase phosphoramidite-based method has been developed for the synthesis of borane phosphonate DNA. Keys to this new approach are replacement of the common 5'-dimethoxytrityl blocking group with a 5'-silyl ether and the use of new protecting groups on the bases (adenine, N6-dimethoxytrityl; cytosine, N4-trimethoxytrityl; guanine, N2-[9-fluorenylmethoxycarbonyl]; thymine, N3-anisoyl). Because of these developments, it is now possible for the first time to synthesize oligodeoxynucleotides having any combination of the four 2'-deoxynucleosides and both phosphate and borane phosphonate internucleotide linkages (including oligomers having exclusively borane phosphonate linkages).     

Reproducibility estimates from single-laboratory ruggedness tests compared with those derived from collaborative trials of six microbiological measurement methods

This work investigated the feasibility of single-laboratory ruggedness experiments to estimate between-laboratory reproducibility. Six microbiological measurement methods that had already been subject to multi-laboratory validation were studied. Ruggedness experiments were designed and executed to determine sensitivity coefficients for factors judged likely to vary between laboratories. These were combined with estimates of factor variation to give reproducibility estimates. The single-laboratory estimates of reproducibility were generally not similar to those generated from multi-laboratory work. The experimental plans were difficult to design and execute, and were only partially successful in producing useful sensitivity coefficients. The authors conclude that ruggedness tests do not offer a single-laboratory alternative to multi-laboratory method validation or a practical approach to the evaluation of measurement uncertainty for microbiological methods. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Campden BRI was previously known as the Campden and Chorleywood Food Research Association.     

Iterative In Situ Click Chemistry Creates Antibody‐like Protein‐Capture Agents

Special agents for protein capture : Iterative in situ click chemistry (see scheme for the tertiary ligand screen) and the one‐bead–one‐compound method for the creation of a peptide library enable the fragment‐based assembly of selective high‐affinity protein‐capture agents. The resulting ligands are water‐soluble and stable chemically, biochemically, and thermally. They can be produced in gram quantities through copper(I)‐catalyzed cycloaddition.

     

Directed cyclic Hamiltonian cycle systems of the complete symmetric digraph

In this paper, we prove that directed cyclic Hamiltonian cycle systems of the complete symmetric digraph, , exist if and only if n is odd with n≠15 and n≠p^α for p an odd prime and α≥2 or with n≠2p^α for p an odd prime and α≥1. We also show that directed cyclic Hamiltonian cycle systems of the complete symmetric digraph minus a set of n/2 vertex-independent digons, (K_n−I)^∗, exist if and only if .     

Characterization of nanoparticles released during construction of photocatalytic pavements using engineered nanoparticles

Graphene, a novel nanomaterial consisting of a single layer of carbon atoms, has attracted significant attention due to its distinctive properties, including great strength, electrical and thermal conductivity, lightness, and potential benefits for diverse applications. The commercialization of scientific discoveries such as graphene is inherently uncertain, with the lag time between the scientific development of a new technology and its adoption by corporate actors revealing the extent to which firms are able to absorb knowledge and engage in learning to implement applications based on the new technology. From this perspective, we test for the existence of three different corporate learning and activity patterns: (1) a linear process where patenting follows scientific discovery; (2) a double-boom phenomenon where corporate (patenting) activity is first concentrated in technological improvements and then followed by a period of technology productization; and (3) a concurrent model where scientific discovery in publications occurs in parallel with patenting. By analyzing corporate publication and patent activity across country and application lines, we find that, while graphene as a whole is experiencing concurrent scientific development and patenting growth, country- and application-specific trends offer some evidence of the linear and double-boom models.