Temperature relaxation in strongly-coupled binary ionic mixtures

The physical and orbital parameters of trans-Neptunian objects provide valuable information about the solar system's formation and evolution. In particular, the characterization of binaries provides insights into the formation mechanisms that may be playing a role at such large distances from the Sun. Studies show two distinct populations, and (38628) Huya occupies an intermediate position between the unequal-sized binaries and those with components of roughly equal sizes. In this work, we predicted and observed three stellar occultation events by Huya. Huya and its satellitewere detected during occultations in 2021 March and again in 2023 June. Additionally, an attempt to detect Huya in 2023 February resulted in an additional single-chord detection of the secondary. A spherical body with a minimum diameter of D = 165 km can explain the three single-chord observations and provide a lower limit for the satellite size. The astrometry of Huya's system, as derived from the occultations and supplemented by observations from the Hubble Space Telescope and Keck Observatory, provided constraints on the satellite orbit and the mass of the system. Therefore, assuming the secondary is in an equatorial orbit around the primary, the limb fitting was constrained by the satellite orbit position angle. The system density, calculated by summing the most precise measurement of Huya's volume to the spherical satellite average volume, is ρ1 = 1073 ± 66 kg m−3. The density that the object would have assuming a Maclaurin equilibrium shape with a rotational period of 6.725 ± 0.01 hr is ρ2 = 768 ± 42 kg m−3. This difference rules out the Maclaurin equilibrium assumption for the main body shape.

Spiral galaxies are ubiquitous in the local Universe. However, the properties of spiral arms in them are still not well studied, and there is even less information concerning spiral structure in distant galaxies. We aim to measure the most general parameters of spiral arms in remote galaxies and trace their changes with redshift. We perform photometric decomposition, including spiral arms, for 159 galaxies from the HST COSMOS and JWST CEERS and JADES surveys, which are imaged in optical and near-infrared rest-frame wavelengths. We confirm that, in our representative sample of spiral galaxies, the pitch angles increase, and the azimuthal lengths decrease with increasing redshift, implying that the spiral structure becomes more tightly wound over time. For the spiral-to-total luminosity ratio and the spiral width-to-disc scale length ratio, we find that band-shifting effects can be as significant as, or even stronger than, evolutionary effects. Additionally, we find that spiral structure becomes more asymmetric at higher redshifts.

The effects of physiologically relevant glucose concentrations on the optical properties of whole blood were measured in-vitro. A concentration increase of +400 mg/dL caused a decrease in the scattering coefficient by 10% over all wavelengths studied. To determine potential mechanisms for the change in the scattering coefficient, we employed optical microscopy to quantify the change in erythrocyte geometry. A 15% change in cell thickness was observed following a glucose increase of +500 mg/dL.

Objective

To investigate the dose-response relationship between dietary sugar and T2D risk.

Methods

MEDLINE, Embase, CINAHL, Web of Science and Cochrane databases were searched through July 9, 2024 for prospective cohorts reporting relative measures of incident T2D risk by categories of dietary sugar (total, free, added, fructose, sucrose) or two beverage sources (non-diet SSB, fruit juice) in healthy adults (Prospero ID: CRD42023401800). Linear and restricted cubic spline dose-response models were fitted for each exposure and study-specific slopes and confidence intervals (CIs) were calculated. Heterogeneity was evaluated using Q-statistics. Risk of bias was evaluated using ROBINS-E tool GRADE approach was applied to assess the certainty of evidence.

Results

Of 10,384 studies, 29 cohorts were included: SSB:18 (n = 541,288); fruit juice:14 (n = 490,413); sucrose: 7 (n = 223,238); total sugar: 4 (n = 109,858); fructose: 5 (n = 158,136); and added sugar: 2 (n = 31,004). Studies were conducted in Europe (13), USA (11), Asia (6), Australia (4), and Latin America (3). Each additional serving of SSB and fruit juice was associated with a higher risk of T2D (RR: 1.25; 95% CI: 1.17–1.35 and RR: 1.05; 95% CI: >1.00–1.11, respectively; moderate certainty). In contrast, 20 g/d intakes of total sugar and sucrose were inversely associated with T2D (RR: 0.96; 95% CI: 0.94–0.98; low certainty; and RR: 0.95; 95% CI: 0.91– <1.00; moderate certainty, respectively). No associations for added sugar (RR: 0.99; 95% CI: 0.96–1.01; low certainty) or fructose (RR: 0.98; 95% CI: 0.83–1.15; very low certainty).

Conclusion

These findings suggest that dietary sugar consumed as a beverage (SSB and fruit juice) is associated with incident T2D risk. The results do not support the common assumption that dietary sugar (i.e., total sugar and sucrose), irrespective of type and amount, is consistently associated with increased T2D risk.

The last decade has shown the great potential that X-ray Free Electron Lasers (FEL) have to study High Energy Density (HED) physics. Experiments at FELs have made significant breakthroughs in Shock Physics and Dynamic Diffraction, Dense Plasma Physics and Warm Dense Matter Science, using techniques such as isochoric heating, inelastic scattering, small angle scattering and X-ray diffraction. In addition, and complementary to these techniques, the coherent properties of the FEL beam can be used to image HED samples with high fidelity. We present new imaging diagnostics and techniques developed at the Matter in Extreme Conditions (MEC) instrument at Linac Coherent Light Source (LCLS) over the last few years. We show results in Phase Contrast Imaging geometry, where the X-ray beam propagates from the target to a camera revealing its phase, as well as in Direct Imaging geometry, where a real image of the sample plane is produced in the camera with a spatial resolution down to 200 nm. Last, we show an implementation of the Talbot Imaging method allowing both X-ray phase and intensity measurements change introduced by a target with sub-micron resolution.

Hybrid perovskite dimensional engineering enables the creation of one- to three-dimensional (1D to 3D) networks of corner-sharing metal halide octahedra interspersed by organic cations, offering opportunities to tailor semiconducting properties through quantum- and dielectric-confinement effects. Beyond the discrete options, intermediate dimensionality has been introduced in the form of quasi-2D phases with inorganic layers of varying thickness. The current study extends this approach to quasi-1D lead-iodide systems with variable ribbon widths from 2 to 6 octahedra, stabilized by flexible molecular configurations, cation mixing of organic cations, or guest molecule selection. This family of quasi-1D structures adopts characteristic well-like configurations, with intraoctahedral distortion increasing from the core to the edges. First-principles density-functional theory (DFT) calculations and optical characterizations─i.e., temperature-dependent UV–visible absorption, electro-absorption, photoluminescence, and circular dichroism─collectively demonstrate lower bandgap and exciton binding energy with increased ribbon width due to tailorable quantum confinement and structural distortions. Access to two ribbon widths within a single well-ordered structure yields distinguishable bandgaps and excitonic properties, demonstrating a class of dual-quantum confinement materials within the perovskite family. Our study serves as a starting point, showcasing a paradigm to stabilize increased ribbon widths through further tuning of organic templating effects. This continuum between 2D and 1D structures offers promise for fine-tuning the dimensionality and optoelectronic properties of hybrid perovskites.