On the role of native contact cooperativity in protein folding.

The consistency of energy landscape theory predictions with available experimental data, as well as direct evidence from molecular simulations, have shown that protein folding mechanisms are largely determined by the contacts present in the native structure. As expected, native contacts are generally energetically favorable. However, there are usually at least as many energetically favorable nonnative pairs owing to the greater number of possible nonnative interactions.

Remembering the Work of Phillip L. Geissler: A Coda to His Scientific Trajectory.

Phillip L. Geissler made important contributions to the statistical mechanics of biological polymers, heterogeneous materials, and chemical dynamics in aqueous environments. He devised analytical and computational methods that revealed the underlying organization of complex systems at the frontiers of biology, chemistry, and materials science.

Trade-offs between Translational and Orientational Order in 2D Superlattices of Polygonal Nanocrystals with Differing Edge Count.

The goal of this work is to identify factors which modulate structural order in 2D self-assembled superlattices of polygon-shaped colloidal nanocrystals. Using combined experimental and simulation techniques, we quantify order in superlattices of hexagonal prism-shaped CdSe/CdS nanocrystals and cube-shaped CsPbBr nanocrystals. Superlattices derived from cube-shaped nanocrystals display less translational order compared to hexagonal prism-shaped nanocrystals both experimentally and in simulations.

Elastic forces drive nonequilibrium pattern formation in a model of nanocrystal ion exchange.

Chemical transformations, such as ion exchange, are commonly employed to modify nanocrystal compositions. Yet the mechanisms of these transformations, which often operate far from equilibrium and entail mixing diverse chemical species, remain poorly understood. Here we explore an idealized model for ion exchange in which a chemical potential drives compositional defects to accumulate at a crystal's surface.

Identification of the interactome of the DP1 receptor for Prostaglandin D: Regulation of DP1 receptor signaling and trafficking by IQGAP1.

Background: Mechanisms governing localization, trafficking and signaling of G protein-coupled receptors (GPCRs) are critical in cell function. Protein-protein interactions are determinant in these processes. However, there are very little interacting proteins known to date for the DP1 receptor for prostaglandin D.

Toward applications of near-field radiative heat transfer with micro-hotplates.

Bringing bodies close together at sub-micron distances can drastically enhance radiative heat transfer, leading to heat fluxes greater than the blackbody limit set by Stefan-Boltzmann law. This effect, known as near-field radiative heat transfer (NFRHT), has wide implications for thermal management in microsystems, as well as technological applications such as direct heat to electricity conversion in thermophotovoltaic cells. Here, we demonstrate NFRHT from microfabricated hotplates made by surface micromachining of [Formula: see text]/[Formula: see text] thin films deposited on a sacrificial amorphous Si layer.

GGA3 interacts with L-type prostaglandin D synthase and regulates the recycling and signaling of the DP1 receptor for prostaglandin D in a Rab4-dependent mechanism.

Mechanisms controlling the recycling of G protein-coupled receptors (GPCRs) remain largely unclear. We report that GGA3 (Golgi-associated, γ adaptin ear containing, ADP-ribosylation factor-binding protein 3) regulates the recycling and signaling of the PGD receptor DP1 through a new mechanism. An endogenous interaction between DP1 and GGA3 was detected by co-immunoprecipitation in HeLa cells.

Systematic review and meta-analysis comparing cognitive vs. image-guided fusion prostate biopsy for the detection of prostate cancer.

Objective: To perform a systematic review and meta-analysis comparing overall prostate cancer detection rate and clinically-significant prostate cancer detection rate between MRI-ultrasound image guided fusion biopsy (MRI-US FB) and cognitive biopsy (CB).

Methods: A systematic review of Pubmed, EMBASE, MEDLINE, and Cochrane library databases was performed. Identified studies were assessed for clinical relevance and excluded based on a set of predefined criteria.

Protracted alterations in muscle activation strategies and knee mechanics in patients after Anterior Cruciate Ligament Reconstruction.

Purpose: Altered quadriceps muscle activity can contribute to reduced ability of the muscle to quickly generate force and appropriately attenuate landing forces, exacerbating poor landing and movement strategies commonly seen after anterior cruciate ligament reconstruction (ACLR). The purpose was to evaluate if electromyographic (EMG) activity and knee biomechanics during a single-limb forward hop task are influenced by a history of ACLR.

Methods: Twenty-six individuals with a history of unilateral ACLR (age 20.

Consequences of Lattice Mismatch for Phase Equilibrium in Heterostructured Solids.

Lattice mismatch can substantially impact the spatial organization of heterogeneous materials. We examine a simple model for lattice-mismatched solids over a broad range of temperature and composition, revealing both uniform and spatially modulated phases. Scenarios for coexistence among them are unconventional due to the extensive mechanical cost of segregation.

L-type prostaglandin D synthase regulates the trafficking of the PGD DP1 receptor by interacting with the GTPase Rab4.

Accumulating evidence indicates that G protein-coupled receptors (GPCRs) interact with Rab GTPases during their intracellular trafficking. How GPCRs recruit and activate the Rabs is unclear. Here, we report that depletion of endogenous L-type prostaglandin D synthase (L-PGDS) in HeLa cells inhibited recycling of the prostaglandin D (PGD) DP1 receptor (DP1) to the cell surface after agonist-induced internalization and that L-PGDS overexpression had the opposite effect.

Unraveling Kinetically-Driven Mechanisms of Gold Nanocrystal Shape Transformations Using Graphene Liquid Cell Electron Microscopy.

Mechanisms of kinetically driven nanocrystal shape transformations were elucidated by monitoring single particle etching of gold nanocrystals using in situ graphene liquid cell transmission electron microscopy (TEM). By systematically changing the chemical potential of the oxidative etching and then quantifying the facets of the nanocrystals, nonequilibrium processes of atom removal could be deduced. Etching at sufficiently high oxidation potentials, both cube and rhombic dodecahedra (RDD)-shaped gold nanocrystals transform into kinetically stable tetrahexahedra (THH)-shaped particles.

Acceptability and feasibility of a Fitbit physical activity monitor for endometrial cancer survivors.

Objective: Endometrial cancer survivors are the least physically active of all cancer survivor groups and exhibit up to 70% obesity. While studies suggest lifestyle interventions result in improved health outcomes, recruitment and availability of these programs are limited. The purpose was to evaluate the acceptability and validity of the Fitbit Alta™ physical activity monitor (Fitbit) for socioculturally diverse endometrial cancer survivors.

Extreme temperature stability of thermally insulating graphene-mesoporous-silicon nanocomposite.

We demonstrate the thermal stability and thermal insulation of graphene-mesoporous-silicon nanocomposites (GPSNC). By comparing the morphology of GPSNC carbonized at 650 °C as-formed to that after annealing, we show that this nanocomposite remains stable at temperatures as high as 1050 °C due to the presence of a few monolayers of graphene coating on the pore walls. This does not only make this material compatible with most thermal processes but also suggests applications in harsh high temperature environments.

Single-particle mapping of nonequilibrium nanocrystal transformations.

Chemists have developed mechanistic insight into numerous chemical reactions by thoroughly characterizing nonequilibrium species. Although methods to probe these processes are well established for molecules, analogous techniques for understanding intermediate structures in nanomaterials have been lacking. We monitor the shape evolution of individual anisotropic gold nanostructures as they are oxidatively etched in a graphene liquid cell with a controlled redox environment.

The inherent dynamics of isotropic- and nematic-phase liquid crystals.

The geodesic (shortest) pathways through the potential energy landscape of a liquid can be thought of as defining what its dynamics would be if thermal noise were removed, revealing what we have called the "inherent dynamics" of the liquid. We show how these inherent paths can be located for a model liquid crystal former, showing, in the process, how the molecular mechanisms of translation and reorientation compare in the isotropic and nematic phases of these systems. These mechanisms turn out to favor the preservation of local orientational order even under macroscopically isotropic conditions (a finding consistent with the experimental observation of pseudonematic domains in these cases), but disfavor the maintenance of macroscopic orientational order, even in the nematic phase.

Novel, gel-free proteomics approach identifies RNF5 and JAMP as modulators of GPCR stability.

The maturation and folding of G protein-coupled receptors are governed by mechanisms that remain poorly understood. In an effort to characterize these biological events, we optimized a novel, gel-free proteomic approach to identify partners of the β2-adrenergic receptor (β2AR). In addition to a number of known interacting proteins such as heterotrimeric G protein subunits, this allowed us to identify proteins involved in endoplasmic reticulum (ER) QC of the receptor.

Inverse agonist and pharmacochaperone properties of MK-0524 on the prostanoid DP1 receptor.

Prostaglandin D₂ (PGD₂) acts through two G protein-coupled receptors (GPCRs), the prostanoid DP receptor and CRTH2 also known as DP1 and DP2, respectively. Several previously characterized GPCR antagonists are now classified as inverse agonists and a number of GPCR ligands are known to display pharmacochaperone activity towards a given receptor. Here, we demonstrate that a DP1 specific antagonist, MK-0524 (also known as laropiprant), decreased basal levels of intracellular cAMP produced by DP1, a Gα(s)-coupled receptor, in HEK293 cells.

[The ODEC (Organization for Development and Community Networks) and mental health: from networking to opening in the local community].

The Organisme de développement et d'entraide communautaire (ODEC) is a nonprofit mental health organization that was established in 1987 and offers mutual help and community development services in the Vallée-de-la-Lièvre region in the Outaouais area of Quebec. Starting with an individual accompaniment service for people living with mental health problems, ODEC has succeeded in establishing a significant mutual help network that now involves more than 100 people. This article comes out of an in-depth case study of ODEC.

[Fighting cholera in shanty-town. Successful experience of a Quebec project adapted to Peru].

Originally designed in Quebec, the MOI project was a collaboration between two professors of social work from Quebec and two members of the Peruvian NGO called SUR in Villa de Salvador, one of poorest slum areas on the outskirts of Lima. The approach is founded on the notion that the body is the primary instrument through which a person can interact with the world around him or her, and that the physical and mental health of an individual exists within the context of healthy conditions of life that must include at least a basic social and health infrastructure as well as healthy hygiene practices on the part of individuals, families and the local community. Preschool children (ages 4-6), study a different part of the body and its proper care each week through classroom observation games.