Generalist versus Specialist Self-Replicators.

Darwinian evolution, including the selection of the fittest species under given environmental conditions, is a major milestone in the development of synthetic living systems. In this regard, generalist or specialist behavior (the ability to replicate in a broader or narrower, more specific food environment) are of importance. Here we demonstrate generalist and specialist behavior in dynamic combinatorial libraries composed of a peptide-based and an oligo(ethylene glycol) based building block.

Emergence of low-symmetry foldamers from single monomers.

Self-assembly is a powerful method to obtain large discrete functional molecular architectures. When using a single building block, self-assembly generally yields symmetrical objects in which all the subunits relate similarly to their neighbours. Here we report the discovery of a family of self-constructing cyclic macromolecules with stable folded conformations of low symmetry, which include some with a prime number (13, 17 and 23) of units, despite being formed from a single component.

Acute Physical Activity, Executive Function, and Attention Performance in Children with Attention-Deficit Hyperactivity Disorder and Typically Developing Children: An Experimental Study.

A growing number of studies support the theory that physical activity can effectively foster the cognitive function of children with attention-deficit hyperactivity disorder (ADHD). The present study examines the effect of acute moderate physical activity on the executive functions and attention performance of (1) typically developing children (without psychological, psychiatric or neurological diagnosis and/or associated treatment stated in their medical history); (2) treatment-naïve ADHD children; and (3) medicated children with ADHD. In the current study, a total sample of 150 (50 non-medicated, 50 medicated, and 50 typically developing) children between the ages of 6 and 12 took part in the experiment.

Executive Function and Attention Performance in Children with ADHD: Effects of Medication and Comparison with Typically Developing Children.

The emerging literature reports that children with Attention-Deficit/Hyperactivity Disorder (ADHD) show deficits in executive functioning. To date, the combination of drug therapy with certain evidence-based non-medication interventions has been proven to be the most effective treatment for ADHD. There is a gap in the literature regarding comparing the executive functions (EF) of treatment naïve and medicated children with ADHD with both each other and typically developing children.

Effector-Triggered Self-Replication in Coupled Subsystems.

In living systems processes like genome duplication and cell division are carefully synchronized through subsystem coupling. If we are to create life de novo, similar control over essential processes such as self-replication need to be developed. Here we report that coupling two dynamic combinatorial subsystems, featuring two separate building blocks, enables effector-mediated control over self-replication.

Antiparallel Dynamic Covalent Chemistries.

The ability to design reaction networks with high, but addressable complexity is a necessary prerequisite to make advanced functional chemical systems. Dynamic combinatorial chemistry has proven to be a useful tool in achieving complexity, however with some limitations in controlling it. Herein we introduce the concept of antiparallel chemistries, in which the same functional group can be channeled into one of two reversible chemistries depending on a controllable parameter.

Self-Assembly Can Direct Dynamic Covalent Bond Formation toward Diversity or Specificity.

With the advent of reversible covalent chemistry the study of the interplay between covalent bond formation and noncovalent interactions has become increasingly relevant. Here we report that the interplay between reversible disulfide chemistry and self-assembly can give rise either to molecular diversity, i.e.

Photooxygenation and gas-phase reactivity of multiply threaded pseudorotaxanes.

The solution-phase photooxygenation of multiply threaded crown/ammonium pseudorotaxanes containing anthracene spacers is monitored by electrospray ionization Fourier-transform ion-cyclotron-resonance (ESI-FTICR) mass spectrometry. The oxygenated pseudorotaxanes are mass-selected and fragmented by infrared multiphoton dissociation (IRMPD) and/or collision-induced dissociation (CID) experiments and and their behavior compared to that of the non-oxygenated precursors. [4+2]Cycloreversion reactions lead to the loss of O2, when no other reaction channel with competitive energy demand is available.

Congenital disorders of glycosylation: a rare cause of nephrotic syndrome.

Congenital disorders of glycosylation (CDG) are inborn errors of metabolism presenting with multi-system organ involvement due to defective glycosylation of glycoproteins. We report here a case of microcephaly, hypotonia, seizure disorder and severe developmental delay since infancy in whom screening for CDG with transferring isoelectric focussing (TIEF) revealed a type I pattern. Following investigation, the specific defect in glycosylation remains to be identified; hence, a diagnosis of CDG Ix (type unknown) was made.

Working together to improve record keeping.

Implementing changes in a hospital setting requires a structured approach to change management. This article describes the process of a project undertaken to improve record keeping in a children's hospital.