Turns around periodic spatial boundaries facilitate increasing event segmentation over time.

Event segmentation is a neurocognitive process bridging perception and episodic memory. To our knowledge, almost all segmentation work is framed towards humans, yet evolutionarily conserved mechanisms in event cognition exist across species. Here, we addressed segmentation in a way that is applicable to humans and non-human animals, inspired by research in rats; specifically, the fragmentation of grid-cell spatial representations following the insertion of boundaries into an environment (forming a corridor maze).

Solvent-induced enantioselectivity reversal in a chiral metal organic framework.

Solvent-induced enantioselectivity reversal is a rarely reported phenomenon in porous homochiral materials. Similar behavior has been studied in chiral high performance liquid chromatography, where minor modifications to the mobile phase can induce elution order reversal of two enantiomers on a chiral stationary phase column. We report the first instance of solvent-induced enantioselectivity reversal in a homochiral metal organic framework.

Structural basis for GTP-induced dimerization and antiviral function of guanylate-binding proteins.

Guanylate-binding proteins (GBPs) form a family of dynamin-related large GTPases which mediate important innate immune functions. They were proposed to form oligomers upon GTP binding/hydrolysis, but the molecular mechanisms remain elusive. Here, we present crystal structures of C-terminally truncated human GBP5 (hGBP5), comprising the large GTPase (LG) and middle (MD) domains, in both its nucleotide-free monomeric and nucleotide-bound dimeric states, together with nucleotide-free full-length human GBP2.

Structural insight into T cell coinhibition by PD-1H (VISTA).

Programmed death-1 homolog (PD-1H), a CD28/B7 family molecule, coinhibits T cell activation and is an attractive immunotherapeutic target for cancer and inflammatory diseases. The molecular basis of its function, however, is unknown. Bioinformatic analyses indicated that PD-1H has a very long Ig variable region (IgV)-like domain and extraordinarily high histidine content, suggesting that unique structural features may contribute to coinhibitory mechanisms.

Upcycling a plastic cup: one-pot synthesis of lactate containing metal organic frameworks from polylactic acid.

Waste PLA can be upcycled to metal organic frameworks of potential high value in a one-pot synthesis scheme, where PLA depolymerisation occurs in situ. Three homochiral lactate based frameworks were successfully synthesised and characterised from PLA as a feed source, including ZnBLD. The chiral separation ability of ZnBLD was maintained.

Local cell coordination does not alter individual cell migration during collective migration but does impact cellular exchange events.

Coordinated cell re-organization is critical to ensure correct tissue morphogenesis for a number of important embryonic and tissue repair events, however the mechanisms that govern cells coordination during collective movements, particularly in situations where cells are spatially restricted by their neighbours, are not well understood. Here we assessed cell re-organization in monolayers of retinal epithelial cells (ARPE-19) to determine if cells that coordinate with their neighbours exhibit differential migration properties to non-coordinating cells and participate differently in local cell re-organization of the tissue sheet. From global tracking analysis, we determined that the movement profiles of cells were indistinguishable regardless of whether or not they were a part of multicellular streams.

Accelerated Discovery of Organic Polymer Photocatalysts for Hydrogen Evolution from Water through the Integration of Experiment and Theory.

Conjugated polymers are an emerging class of photocatalysts for hydrogen production where the large breadth of potential synthetic diversity presents both an opportunity and a challenge. Here, we integrate robotic experimentation with high-throughput computation to navigate the available structure-property space. A total of 6354 co-polymers was considered computationally, followed by the synthesis and photocatalytic characterization of a sub-library of more than 170 co-polymers.

A Multifunctional, Charge-Neutral, Chiral Octahedral M L Cage.

A chiral, octahedral M L cage, which is charge neutral and contains an internal void of about 2000 Å , is reported. The cage was synthesised as an enantiopure complex by virtue of amino-acid-based dicarboxylate ligands, which assemble around copper paddlewheels at the vertices of the octahedron. The cage persists in solution with retention of the fluorescence properties of the parent acid.

The simplest supramolecular helix.

Diethylamine is the smallest and simplest molecule that features a supramolecular helix as its lowest energy aggregate. Structural studies and large scale sampling simulations show that the helical arrangement is more stable than cyclic structures, which are the dominant species for other small hydrogen bonding molecules.

Missing Linker Defects in a Homochiral Metal-Organic Framework: Tuning the Chiral Separation Capacity.

Efficient chiral separation remains a very challenging task due to the identical physical and chemical properties of the enantiomers of a molecule. Enantiomers only behave differently from each other in the presence of other chiral species. Homochiral metal-organic frameworks (MOFs) have received much attention for their promising enantioseparation properties.

Modulation of cellular polarization and migration by ephrin/Eph signal-mediated boundary formation.

Compartment boundaries are essential for ensuring proper cell organization during embryo development and in adult tissues, yet the mechanisms underlying boundary establishment are not completely understood. A number of mechanisms, including (i) differential adhesion, (ii) differential tension, and (iii) cell signaling-mediated cell repulsion, are known to contribute and likely a context-dependent balance of each of these dictates boundary implementation. The ephrin/Eph signaling pathway is known to impact boundary formation in higher animals.

Functional materials discovery using energy-structure-function maps.

Molecular crystals cannot be designed in the same manner as macroscopic objects, because they do not assemble according to simple, intuitive rules. Their structures result from the balance of many weak interactions, rather than from the strong and predictable bonding patterns found in metal-organic frameworks and covalent organic frameworks. Hence, design strategies that assume a topology or other structural blueprint will often fail.

Visible-Light-Driven Hydrogen Evolution Using Planarized Conjugated Polymer Photocatalysts.

Linear poly(p-phenylene)s are modestly active UV photocatalysts for hydrogen production in the presence of a sacrificial electron donor. Introduction of planarized fluorene, carbazole, dibenzo[b,d]thiophene or dibenzo[b,d]thiophene sulfone units greatly enhances the H evolution rate. The most active dibenzo[b,d]thiophene sulfone co-polymer has a UV photocatalytic activity that rivals TiO, but is much more active under visible light.

Visible-Light-Driven Hydrogen Evolution Using Planarized Conjugated Polymer Photocatalysts.

Linear poly(p-phenylene)s are modestly active UV photocatalysts for hydrogen production in the presence of a sacrificial electron donor. Introduction of planarized fluorene, carbazole, dibenzo[b,d]thiophene or dibenzo[b,d]thiophene sulfone units greatly enhances the H2 evolution rate. The most active dibenzo[b,d]thiophene sulfone co-polymer has a UV photocatalytic activity that rivals TiO2, but is much more active under visible light.

An in vitro model of tissue boundary formation for dissecting the contribution of different boundary forming mechanisms.

During development and in adult tissues separation of phenotypically distinct cell populations is necessary to ensure proper organization and function of tissues and organs. Various phenomena, such as differential adhesion, differential mechanical tension and cell-cell repulsion, are proposed to cause boundary formation. Moreover, emerging evidence suggests that interplay between multiple such phenomena can underlie boundary formation.

Nonautonomous contact guidance signaling during collective cell migration.

Directed migration of groups of cells is a critical aspect of tissue morphogenesis that ensures proper tissue organization and, consequently, function. Cells moving in groups, unlike single cells, must coordinate their migratory behavior to maintain tissue integrity. During directed migration, cells are guided by a combination of mechanical and chemical cues presented by neighboring cells and the surrounding extracellular matrix.

An algorithm to quantify correlated collective cell migration behavior.

Collective cell migration is an important process that determines cell reorganization in a number of biological events such as development and regeneration. Random cell reorganization within a confluent monolayer is a popular in vitro model system for understanding the mechanisms that underlie coordination between neighboring cells during collective motion. Here we describe a simple automated C++ algorithm to quantify the width of streams of correlated cells moving within monolayers.

A perylene diimide rotaxane: synthesis, structure and electrochemically driven de-threading.

The first example of a [2]-rotaxane in which a perylene diimide acts as a recognition site has been synthesised and characterised. The interlocked nature of the compound has been verified by both NMR studies and an X-ray structure determination. Electrochemical investigations confirm that the nature of the redox processes associated with the perylene diimide are modified by the complexation process and that it is possible to mono-reduce the [2]-rotaxane to give a radical anion based rotaxane.