On the Ostwald ripening of crystalline and amorphous nanoparticles.

Ostwald ripening of crystalline and amorphous nanoparticle dispersions of a model organic compound are compared. While amorphous nanoparticles show a rapid ripening on the timescale of minutes, the crystalline nanoparticles do not ripen within the timescale of weeks. A metastable zone for crystal growth, presumably involving a free energy barrier, is identified, and we propose that this explains the absence of Ostwald ripening in the nanocrystal dispersion.

Associations between body composition, metabolic mediators and osteoarthritis in cats.

Background: Osteoarthritis (OA) is a common, age-related joint disease in cats. The common finding of bilateral symmetric joint involvement may suggest influence from systemic factors, and could imply that body parameters such as excess body fat and cat size are important for OA development. We aimed to investigate associations between body composition and whole-body OA scores in 72 cats, using whole-body computed tomography (CT), and if serum concentrations of the metabolic mediators leptin, adiponectin and insulin-like growth factor-1 (IGF-1) reflected the total OA load.

On the reversibility of amyloid fibril formation.

Amyloids are elongated supramolecular protein self-assemblies. Their formation is a non-covalent assembly process and as such is fully reversible. Amyloid formation is associated with several neurodegenerative diseases, and the reversibility is key to maintaining the healthy state.

On the thermal and chemical stability of DNAJB6b and its globular domains.

The chaperone DNAJB6b (JB6) plays important roles in increasing amyloid protein solubility and inhibiting amyloid fibril formation, a causative factor for neurodegenerative diseases like Alzheimer's and Parkinson's disease. Insights into the biophysical properties of JB6, including its structure, self-assembly and stability towards denaturation, may enhance the understanding of the physicochemical basis of chaperone action. However, many of the biophysical properties of the chaperone remain elusive.

Nanofibrous Peptide Hydrogels Leveraging Histidine to Modulate pH-Responsive Supramolecular Assembly and Antibody Release.

In this work, we investigate the pH-responsive behavior of multidomain peptide (MDP) hydrogels containing histidine. Small-angle X-ray scattering confirmed that MDP nanofibers sequester nonpolar residues into a hydrophobic core surrounded by a shell of hydrophilic residues. MDPs with histidine on the hydrophilic face formed nanofibers at all pH values tested, but the morphology of the fibers was influenced by the protonation state and the location of histidine in the MDP sequence.

Serine phosphorylation mimics of Aβ form distinct, non-cross-seeding fibril morphs.

The self-assembly of amyloid-β peptide (Aβ) into fibrils and oligomers is linked to Alzheimer's disease (AD). Fibrillar aggregates in AD patient's brains contain several post-translational modifications, including phosphorylation at positions 8 and 26. These play a key role in modifying the aggregation propensity of Aβ, yet how they affect the mechanism of aggregation is only poorly understood.

Insights into the Hierarchical Assembly of a Chemically Diverse Peptide Hydrogel Derived from Human Semenogelin I.

A peptide corresponding to a 13-residue segment of the human protein semenogelin I has been shown to generate a hydrogel consisting of amyloid-like fibrils. The relative chemical diversity (compared to synthetic sequences) with 11 distinct amino acids makes this peptide (P0) an ideal candidate for investigating the role of individual residues in gelation. Herein, the terminal residues have been sequentially removed to furnish a series of truncated peptides, P1-P10, ranging from 12 to 3 residues in length.

The Ability of DNAJB6b to Suppress Amyloid Formation Depends on the Chaperone Aggregation State.

For many chaperones, a propensity to self-assemble correlates with function. The highly efficient amyloid suppressing chaperone DNAJB6b has been reported to oligomerize. A key question is whether the DNAJB6b self-assemblies or their subunits are active units in the suppression of amyloid formation.

Measuring the menu, not the food: "psychometric" data may instead measure "lingometrics" (and miss its greatest potential).

This is a review of a range of empirical studies that use digital text algorithms to predict and model response patterns from humans to Likert-scale items, using texts only as inputs. The studies show that statistics used in construct validation is predictable on sample and individual levels, that this happens across languages and cultures, and that the relationship between variables are often semantic instead of empirical. That is, the relationships among variables are given a priori and evidently computable as such.

Nurses' perceptions of patient involvement in shared decision-making in cardiovascular care.

It is important for nurses to involve patients in their own care to enable shared decision-making. This study aimed to explore the perceptions of nurses regarding the degree to which involvement in shared decision-making takes place in clinical settings during consultations. Previous studies have shown that the use of shared decision-making by healthcare professionals can improve their caring practices and the quality of life of their patients.

On the micelle formation of DNAJB6b.

The human chaperone DNAJB6b increases the solubility of proteins involved in protein aggregation diseases and suppresses the nucleation of amyloid structures. Due to such favourable properties, DNAJB6b has gained increasing attention over the past decade. The understanding of how DNAJB6b operates on a molecular level may aid the design of inhibitors against amyloid formation.

Longitudinal study of the immune response and memory following natural bovine respiratory syncytial virus infections in cattle of different age.

Human and bovine respiratory syncytial virus (HRSV and BRSV) are closely genetically related and cause respiratory disease in their respective host. Whereas HRSV vaccines are still under development, a multitude of BRSV vaccines are used to reduce clinical signs. To enable the design of vaccination protocols to entirely stop virus circulation, we aimed to investigate the duration, character and efficacy of the immune responses induced by natural infections.

α-Synuclein Interaction with Lipid Bilayer Discs.

α-Synuclein (aSyn) is a 140 residue long protein present in presynaptic termini of nerve cells. The protein is associated with Parkinson's disease, in which case it has been found to self-assemble into long amyloid fibrils forming intracellular inclusions that are also rich in lipids. Furthermore, its synaptic function is proposed to involve interaction with lipid membranes, and hence, it is of interest to understand aSyn-lipid membrane interactions in detail.

A novel X-ray diffraction approach to assess the crystallinity of regenerated cellulose fibers.

Here, a new accurate approach is presented to quantify the degree of crystallinity of regenerated cellulose textile fibers using wide-angle X-ray scattering. The approach is based on the observation that the contributions to the scattering from crystalline and amorphous domains of the fibers can be separated due to their different degree of orientation with respect to the fiber direction. The method is tested on Ioncell-F fibers, dry jet wet spun with different draw ratios from an ionic liquid solution.

Amyloid β 42 fibril structure based on small-angle scattering.

Amyloid fibrils are associated with a number of neurodegenerative diseases, including fibrils of amyloid β42 peptide (Aβ42) in Alzheimer's disease. These fibrils are a source of toxicity to neuronal cells through surface-catalyzed generation of toxic oligomers. Detailed knowledge of the fibril structure may thus facilitate therapeutic development.

On the Cluster Formation of α-Synuclein Fibrils.

The dense accumulation of α-Synuclein fibrils in neurons is considered to be strongly associated with Parkinson's disease. These intracellular inclusions, called Lewy bodies, also contain significant amounts of lipids. To better understand such accumulations, it should be important to study α-Synuclein fibril formation under conditions where the fibrils lump together, mimicking what is observed in Lewy bodies.

Strong inhibition of peptide amyloid formation by a fatty acid.

The aggregation of peptides into amyloid fibrils is associated with several diseases, including Alzheimer's and Parkinson's disease. Because hydrophobic interactions often play an important role in amyloid formation, the presence of various hydrophobic or amphiphilic molecules, such as lipids, may influence the aggregation process. We have studied the effect of a fatty acid, linoleic acid, on the fibrillation process of the amyloid-forming model peptide NACore (GAVVTGVTAVA).

Multiscale Structural Elucidation of Peptide Nanotubes by X-Ray Scattering Methods.

This mini-review presents the structural investigations of the self-assembled peptide nanotubes using X-ray scattering techniques. As compared to electron microscopy, scattering methods enable studies of nanotubes in solution under the appropriate physicochemical conditions and probe their formation mechanism. In addition, a combination of X-ray scattering methods allow the elucidation of structural organization from the molecular scale to the dimension of nanotubes.

SAXS/WAXS Investigation of Amyloid-β(16-22) Peptide Nanotubes.

This brief report presents an X-ray scattering investigation of self-assembled nanotubes formed by a short peptide. X-ray scattering methods enable multiscale structural elucidation of these nanotubes in solution under the same conditions involved in the self-assembly process. In particular, the dimensions of nanotubes and the crystalline organization within their walls can be determined quantitatively.

Characterization of Iron and Organic Carbon Colloids in Boreal Rivers and Their Fate at High Salinity.

Riverine colloids are important carriers of macronutrients, trace metals, and pollutants into marine waters. The aim of the current study was to extend the understanding of iron (Fe) and organic carbon (OC) colloids in boreal rivers and their fate at higher salinities. X-ray absorbance spectroscopy (XAS) and dynamic light scattering (DLS) were combined to explore Fe speciation and colloidal characteristics such as size and surface charge and how these are affected at increasing salinity.

The 3Rs in animal welfare bodies at Swedish universities - knowledge, attitudes, implementation.

The implementation of the 3Rs (replacement, reduction and refinement) is emphasized in EU Directive 2010/63. The task of the animal welfare bodies (AWB) is to strengthen animal welfare and develop the 3Rs at research animal facilities. In 2016, we surveyed the knowledge on, attitudes towards and implementation of the 3Rs within AWBs at eight major Swedish universities.