What is the best simulation approach for measuring local density fluctuations near solvo-/hydrophobes?

Measurements of local density fluctuations are crucial to characterizing the interfacial properties of equilibrium fluids. A specific case that has been well-explored involves the heightened compressibility of water near hydrophobic entities. Commonly, a spatial profile of local fluctuation strength is constructed from the measurements of the mean and variance of solvent particle number fluctuations in a set of contiguous subvolumes of the system adjacent to the solvo-/hydrophobe.

Partial and complete wetting of droplets of active Brownian particles.

We study wetting droplets formed of active Brownian particles in contact with a repulsive potential barrier, in a wedge geometry. Our numerical results demonstrate a transition between partially wet and completely wet states, as a function of the barrier height, analogous to the corresponding surface phase transition in passive fluids. We analyse partially wet configurations characterised by a nonzero contact angle between the droplet surface and the barrier including the average density profile and its fluctuations.

Reaction with Water Vapor Defines Surface Reconstruction and Membranolytic Activity of Quartz Milled in Different Molecular Environments.

Industrial processing of quartz (SiO) and quartz-containing materials produces toxic dust. Fracturing quartz crystals opens the Si‒O bond and produces highly reactive surface species which mainly react with molecules like water and oxygen. This surface-reconstruction process forms silanol (Si‒OH) on the quartz surface, which can damage biological membranes under specific configurations.

Distinct Pro-Inflammatory Mechanisms Elicited by Short and Long Amosite Asbestos Fibers in Macrophages.

While exposure to long amphibolic asbestos fibers (L > 10 µm) results in the development of severe diseases including inflammation, fibrosis, and mesothelioma, the pathogenic activity associated with short fibers (L < 5 µm) is less clear. By exposing murine macrophages to short (SFA) or long (LFA) fibers of amosite asbestos different in size and surface chemistry, we observed that SFA internalization resulted in pyroptotic-related immunogenic cell death (ICD) characterized by the release of the pro-inflammatory damage signal (DAMP) IL-1α after inflammasome activation and gasdermin D (GSDMD)-pore formation. In contrast, macrophage responses to non-internalizable LFA were associated with tumor necrosis factor alpha (TNF-α) release, caspase-3 and -7 activation, and apoptosis.

Biases in inverse Ising estimates of near-critical behavior.

Inverse Ising inference allows pairwise interactions of complex binary systems to be reconstructed from empirical correlations. Typical estimators used for this inference, such as pseudo-likelihood maximization (PLM), are biased. Using the Sherrington-Kirkpatrick model as a benchmark, we show that these biases are large in critical regimes close to phase boundaries, and they may alter the qualitative interpretation of the inferred model.

Physico-Chemical Approaches to Investigate Surface Hydroxyls as Determinants of Molecular Initiating Events in Oxide Particle Toxicity.

The study of molecular recognition patterns is crucial for understanding the interactions between inorganic (nano)particles and biomolecules. In this review we focus on hydroxyls (OH) exposed at the surface of oxide particles (OxPs) which can play a key role in molecular initiating events leading to OxPs toxicity. We discuss here the main analytical methods available to characterize surface OH from a quantitative and qualitative point of view, covering thermogravimetry, titration, ζ potential measurements, and spectroscopic approaches (NMR, XPS).

Probing excitations and cooperatively rearranging regions in deeply supercooled liquids.

Upon approaching the glass transition, the relaxation of supercooled liquids is controlled by activated processes, which become dominant at temperatures below the so-called dynamical crossover predicted by Mode Coupling theory (MCT). Two of the main frameworks rationalising this behaviour are dynamic facilitation theory (DF) and the thermodynamic scenario which give equally good descriptions of the available data. Only particle-resolved data from liquids supercooled below the MCT crossover can reveal the microscopic mechanism of relaxation.

Mechanisms and shapes of causal exposure-response functions for asbestos in mesotheliomas and lung cancers.

This paper summarizes recent insights into causal biological mechanisms underlying the carcinogenicity of asbestos. It addresses their implications for the shapes of exposure-response curves and considers recent epidemiologic trends in malignant mesotheliomas (MMs) and lung fiber burden studies. Since the commercial amphiboles crocidolite and amosite pose the highest risk of MMs and contain high levels of iron, endogenous and exogenous pathways of iron injury and repair are discussed.

Waterborne asbestos: Good practices for surface waters analyses.

Asbestos occurrence has been mainly monitored in air so far and only limitedly considered in other matrices, such as water. Waterborne asbestos could originate from natural or anthropogenic sources, leading to non-conventional exposure scenarios. It could be a secondary source of airborne asbestos in case of water-to-air migration, particularly in case of surface moving water, such as in rivers and streams.

Cytotoxicity of fibrous antigorite from New Caledonia.

Exposure to asbestos and asbestos-like minerals has been related to the development of severe lung diseases, including cancer and malignant mesothelioma (MM). A high incidence of non-occupational MM was observed in New Caledonia (France) in people living in proximity of serpentinite outcrops, containing chrysotile and fibrous antigorite. Antigorite is a magnesium silicate, which shares with chrysotile asbestos the chemical formula.

Top-Down Preparation of Nanoquartz for Toxicological Investigations.

Occupational exposure to quartz dust is associated with fatal diseases. Quartz dusts generated by mechanical fracturing are characterized by a broad range of micrometric to nanometric particles. The contribution of this nanometric fraction to the overall toxicity of quartz is still largely unexplored, primarily because of the strong electrostatic adhesion forces that prevent isolation of the nanofraction.

Molecular recognition between membrane epitopes and nearly free surface silanols explains silica membranolytic activity.

Inhaled crystalline silica causes inflammatory lung diseases, but the mechanism for its unique activity compared to other oxides remains unclear, preventing the development of potential therapeutics. Here, the molecular recognition mechanism between membrane epitopes and "nearly free silanols" (NFS), a specific subgroup of surface silanols, is identified and proposed as a novel broad explanation for particle toxicity in general. Silica samples having different bulk and surface properties, specifically different amounts of NFS, are tested with a set of membrane systems of decreasing molecular complexity and different charge.

Direct imaging of contacts and forces in colloidal gels.

Colloidal dispersions are prized as model systems to understand the basic properties of materials and are central to a wide range of industries from cosmetics to foods to agrichemicals. Among the key developments in using colloids to address challenges in condensed matter is to resolve the particle coordinates in 3D, allowing a level of analysis usually only possible in computer simulations. However, in amorphous materials, relating mechanical properties to microscopic structure remains problematic.

Dominating lengthscales of zebrafish collective behaviour.

Collective behaviour in living systems is observed across many scales, from bacteria to insects, to fish shoals. Zebrafish have emerged as a model system amenable to laboratory study. Here we report a three-dimensional study of the collective dynamics of fifty zebrafish.

Wetting Transition of Active Brownian Particles on a Thin Membrane.

We study nonequilibrium analogues of surface phase transitions in a minimal model of active particles in contact with a purely repulsive potential barrier that mimics a thin porous membrane. Under conditions of bulk motility-induced phase separation, the interaction strength ϵ_{w} of the barrier controls the affinity of the dense phase for the barrier region. We uncover clear signatures of a wetting phase transition as ϵ_{w} is varied.

Chrysotile asbestos migration in air from contaminated water: An experimental simulation.

In Naturally Occurring Asbestos (NOA) rich areas, water flows through asbestos bearing rocks and soils and generates waterborne fibres that may migrate in air and become a risk for humans. Research on the migration and dispersion after water vaporisation has been so far only marginally evaluated. This study investigates the migration in air of asbestos from a set of suspensions contaminated by chrysotile from Balangero (Italy), under controlled laboratory conditions.

Elimination from wastewater of antibiotics reserved for hospital settings, with a Fenton process based on zero-valent iron.

The Fenton process activated by Zero Valent Iron (ZVI-Fenton) is shown here to effectively remove antibiotics reserved for hospital settings (specifically used to treat antibiotic-resistant infections) from wastewater, thereby helping in the fight against bacterial resistance. Effective degradation of cefazolin, imipenem and vancomycin in real urban wastewater was achieved at pH 5, which is quite near neutrality when compared with classic Fenton that works effectively at pH 3-4. The possibility to operate successfully at pH 5 has several advantages compared to operation at lower pH values: (i) lower reagent costs for pH adjustment; (ii) insignificant impact on wastewater conductivity, because lesser acid is required to acidify and lesser or no base for neutralization; (iii) undetectable release of dissolved Fe, which could otherwise be an issue for wastewater quality.

3D assessment of intervertebral disc degeneration in zebrafish identifies changes in bone density that prime disc disease.

Back pain is a common condition with a high social impact and represents a global health burden. Intervertebral disc disease (IVDD) is one of the major causes of back pain; no therapeutics are currently available to reverse this disease. The impact of bone mineral density (BMD) on IVDD has been controversial, with some studies suggesting osteoporosis as causative for IVDD and others suggesting it as protective for IVDD.

Antioxidant Activity of Silica-Based Bioactive Glasses.

Bioactive glasses are the materials of choice in the field of bone regeneration. Antioxidant properties of interest to limit inflammation and foreign body reactions have been conferred to bioactive glasses by the addition of appropriate ions (such as Ce or Sr). On the other hand, the antioxidant activity of bioactive glasses without specific ion/molecular doping has been occasionally cited in the literature but never investigated in depth.