The influence of key physicochemical variables such as density, molecular weight, branching, and thermal history on the dynamic mechanical behavior of polyethylene has been studied. On the basis of our own results and the subject literature, the mechanisms for the -, ß-, and 7-relaxation processes are reviewed. The mechanism of «-relaxation appears to be well established; i.e., it is due to motions of the interfacial regions (tie molecules, folds, loops, etc.) which require chain mobility in the crystal as a precursor and its temperature depends solely on the crystallite (lamellae) thickness. Our results on ^-relaxation suggest it to be a glass transition. The 7-relaxation process involves the motion of a short polymer segment (e.g., three to four CH2) belonging to the bulk amorphous fraction and the chain ends within the crystalline or amorphous phases. The data on energy dissipation and stiffness for various polyethylenes are also presented.

Molecular recognition reagents are key tools for understanding biological processes and are used universally by scientists to study protein expression, localisation and interactions. Antibodies remain the most widely used of such reagents and many show excellent performance, although some are poorly characterised or have stability or batch variability issues, supporting the use of alternative binding proteins as complementary reagents for many applications. Here we report on the use of Affimer proteins as research reagents. We selected 12 diverse molecular targets for Affimer selection to exemplify their use in common molecular and cellular applications including the (a) selection against various target molecules; (b) modulation of protein function in vitro and in vivo; (c) labelling of tumour antigens in mouse models; and (d) use in affinity fluorescence and super-resolution microscopy. This work shows that Affimer proteins, as is the case for other alternative binding scaffolds, represent complementary affinity reagents to antibodies for various molecular and cell biology applications.DOI: http://dx.doi.org/10.7554/eLife.24903.001

Owing to their unusual Lewis acidic properties, the coordination chemistry of fluorinated organomercurials is attracting increasing interest. In this review, the authors focus on the synthesis, structures, and properties of neutral Lewis adducts involving fluorinated organomercurials such as (CF 3 ) 2 Hg, (C 6 F 5 )HgCl, (C 6 F 5 ) 2 Hg, and [(o-C 6 F 4 )Hg] 3 . While most of these organomercurials form adducts with common Lewis basic organic substrates, [(o-C 6 F 4 )Hg] 3 also interacts with aromatic hydrocarbons, alkynes, N-heterocycles, and metallocenes to form π-complexes. In some cases, this complexation mode results in the formation of supramolecules with unusual luminescence properties or microporosity.

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There were unexplained differences among HCV population subgroups in the receipt of new DAA treatment. Targeted interventions are needed for black patients and younger women.