The thermodynamic stabilities of consecutive mismatches at the ends of RNA helices are determined by the 3' terminal nucleotides. More than 40 RNA duplexes containing terminal motifs of 3 or more nucleotides were studied by optical melting experiments. Up to three noncanonical pairs of nucleotides at the end of RNA helices provide additional thermodynamic stability. 3' nucleotides contribute more stability than 5' nucleotides, and purines contribute more stability than pyrimidines. The additional stability of a second or third 3' nucleotide stacking on a purine is the same for both dangling ends and consecutive terminal mismatches. Current predictions underestimate RNA duplex stabilities with terminal motifs by 1.4 kcal/mol on average, which is an order of magnitude in a binding constant at 37 degrees C. Accurate thermodynamic parameters for these terminal motifs will contribute to improvements in RNA secondary structure predictions, identification of microRNA targets, and design of siRNA therapeutics with fewer off-target effects.

The synthesis of three new 1,4‐diketo‐3,6‐diphenyl‐pyrrolo[3,4‐c]pyrrole (DPP) macromolecules appended with two or four quaterfluorene arms is reported. The compounds absorb mainly through the oligofluorene units and emit through the DPP core. Optical gain has been observed for Linear‐c, a two‐armed structure in which the quaterfluorene units are conjugated through the core unit.

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PurposeKnowledge management (KM) is a key driver of organisational growth and development. It is a major conduit for the development of varying organisational capitals, and pivotal to learning, innovation and employee engagement. It is the authors' belief that KM has over‐focused on structures, processes and technologies and not enough on learning, innovation and engagement. This paper aims to discuss these issues.Design/methodology/approachThe paper draws on experience and research from within the Chartered Institute of Personnel and Development in the UK since 2000 and up to 2012, as well as external research sources.FindingsThis lack of alignment can be attributed to three issues: the often diffuse and vague nature of the concept itself; the undue focus on tracking, capturing and storing KM assets; and the lack of a coherent organisational purpose and focus for knowledge management.Practical implicationsThe paper suggests that by focusing on the three key areas of learning, innovation and engagement, both a business rationale for KM and a “why bother” focus for employees can be developed, as well as contributing to sustainable organisation performance.Originality/valueThe paper examines knowledge management and links it to core HR processes.

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