An autonomous molecular assembler for programmable chemical synthesis

Molecular machines that assemble polymers in a programmed sequence are fundamental to life. They are also an achievable goal of nanotechnology. Here, we report synthetic molecular machinery made from DNA which controls and records the formation of covalent bonds. We show that an autonomous cascade of DNA hybridization reactions can create oligomers, from building blocks linked by olefin or peptide bonds, with a sequence defined by a reconfigurable molecular program. The system can also be programmed to achieve combinatorial assembly. The sequence of assembly reactions, and thus the structure, of each oligomer synthesized is recorded in a DNA molecule which enables this information to be recovered by PCR amplification followed by DNA sequencing

Participatory methods in pediatric participatory research : a systematic review

Meaningful child participation in medical research is seen as important. In order to facilitate further development of participatory research, we performed a systematic literature study to describe and assess the available knowledge on participatory methods in pediatric research. A search was executed in five databases: PubMed, CINAHL, PsycINFO, Scopus and Cochrane. After careful screening of relevant papers, finally 24 documents were included in our analysis. Literature on participatory methods in pediatric research appears generally to be descriptive, whereby high quality evidence is lacking. Overall, five groups of participatory methods for children could be distinguished: observational, verbal, written, visual and active methods. The choice for one of these methods should be based on the child's age, on social and demographic characteristics and on the research objectives. To date, these methods are still solely used for obtaining data, yet they are suitable for conducting meaningful participation. This may result in a successful partnership between children and researchers. Researchers conducting participatory research with children can use this systematic review in order to weigh the current knowledge about the participatory methods presented.Pediatric Research (2015); doi:10.1038/pr.2015.279