Having a compact yet robust structurally based identifier or representation system is a key enabling factor for efficient sharing and dissemination of research results within the chemistry community, and such systems lay down the essential foundations for future informatics and data-driven research. While substantial advances have been made for small molecules, the polymer community has struggled in coming up with an efficient representation system. This is because, unlike other disciplines in chemistry, the basic premise that each distinct chemical species corresponds to a well-defined chemical structure does not hold for polymers. Polymers are intrinsically stochastic molecules that are often ensembles with a distribution of chemical structures. This difficulty limits the applicability of all deterministic representations developed for small molecules. In this work, a new representation system that is capable of handling the stochastic nature of polymers is proposed. The new system is based on the popular “simplified molecular-input line-entry system” (SMILES), and it aims to provide representations that can be used as indexing identifiers for entries in polymer databases. As a pilot test, the entries of the standard data set of the glass transition temperature of linear polymers (Bicerano, 2002) were converted into the new BigSMILES language. Furthermore, it is hoped that the proposed system will provide a more effective language for communication within the polymer community and increase cohesion between the researchers within the community.

No abstract

Deciphering the significance of length, sequence, and stereochemistry in block copolymer self-assembly remains an ongoing challenge. A dearth of methods to access uniform block co-oligomers/polymers with precise stereochemical sequences has precluded such studies. Here, we develop iterative exponential growth (IEG) methods for the synthesis of a small library of unimolecular stereoisomeric diblock 32-mers. X-ray scattering reveals that stereochemistry modulates the phase behavior of these polymers, which we rationalize based on simulations carried out on a theoretical model system. This work demonstrates that stereochemical sequence can play a crucial role in unimolecular polymer self-assembly.

BackgroundAlthough diabetic retinopathy (DR) has long been considered as a microvascular disorder, mounting evidence suggests that diabetic retinal neurodegeneration, in particular synaptic loss and dysfunction of retinal ganglion cells (RGCs) may precede retinal microvascular changes. Key molecules involved in this process remain poorly defined. The microtubule-associated protein tau is a critical mediator of neurotoxicity in Alzheimer’s disease (AD) and other neurodegenerative diseases. However, the effect of tau, if any, in the context of diabetes-induced retinal neurodegeneration has yet to be ascertained. Here, we investigate the changes and putative roles of endogeneous tau in diabetic retinal neurodegeneration.MethodsTo this aim, we combine clinically used electrophysiological techniques, i.e. pattern electroretinogram and visual evoked potential, and molecular analyses in a well characterized high-fat diet (HFD)-induced mouse diabetes model in vivo and primary retinal ganglion cells (RGCs) in vitro.ResultsWe demonstrate for the first time that tau hyperphosphorylation via GSK3β activation causes vision deficits and synapse loss of RGCs in HFD-induced DR, which precedes retinal microvasculopathy and RGCs apoptosis. Moreover, intravitreal administration of an siRNA targeting to tau or a specific inhibitor of GSK3β reverses synapse loss and restores visual function of RGCs by attenuating tau hyperphosphorylation within a certain time frame of DR. The cellular mechanisms by which hyperphosphorylated tau induces synapse loss of RGCs upon glucolipotoxicity include i) destabilizing microtubule tracks and impairing microtubule-dependent synaptic targeting of cargoes such as mRNA and mitochondria; ii) disrupting synaptic energy production through mitochondria in a GSK3β-dependent manner.ConclusionsOur study proposes mild retinal tauopathy as a new pathophysiological model for DR and tau as a novel therapeutic target to counter diabetic RGCs neurodegeneration occurring before retinal vasculature abnormalities.Electronic supplementary materialThe online version of this article (10.1186/s13024-018-0295-z) contains supplementary material, which is available to authorized users.

Amorphous, hydrogenated, and self-ordered nanoporous Nb O films serve as an excellent binder-free electrode for sodium batteries, affording a high and sustainable capacity delivery and robust high-rate capability. This collaborative material engineering of structural order (amorphization), composition (hydrogenation), and architecture (ordered nanopore) opens up new possibilities to develop an energy storage solution that is more accessible, sustainable, and producible.

No abstract

No abstract

In this work, three-dimensional porous Ni–Co layered double hydroxide nanosheets are vertically decorated on N-doped reduced graphene oxide via a simple one-step microwave-assisted hydrothermal process.