Higher-order topological phases in non-Hermitian photonics revolutionize the understanding of wave propagation and modulation, which lead to hierarchical states in open systems. However, intrinsic insulating properties endorsed by the lattice symmetry of photonic crystals fundamentally confine the robust transport only at explicit system boundaries, letting alone the flexible reconfiguration in hierarchical states at arbitrary positions. Here, we report a dynamic topological platform for creating the reconfigurable hierarchical bound states in heat transport systems and observe the robust and nonlocalized higher-order states in both the real- and imaginary-valued bands. Our experiments showcase that the hierarchical features of zero-dimension corner and nontrivial edge modes occur at tailored positions within the system bulk states instead of the explicit system boundaries. Our findings uncover the mechanism of non-localized hierarchical non-trivial topological states and offer distinct paradigms for diffusive transport field management.

UNASSIGNED: In the photoacoustic (PA) technique, the laser irradiation in the time domain (i.e., laser pulse duration) governs the characteristics of PA imaging-it plays a crucial role in the optical-acoustic interaction, the generation of PA signals, and the PA imaging performance.
UNASSIGNED: We aim to provide a comprehensive analysis of the impact of laser pulse duration on various aspects of PA imaging, encompassing the signal-to-noise ratio, the spatial resolution of PA imaging, the acoustic frequency spectrum of the acoustic wave, the initiation of specific physical phenomena, and the photothermal-PA (PT-PA) interaction/conversion.
UNASSIGNED: By surveying and reviewing the state-of-the-art investigations, we discuss the effects of laser pulse duration on the generation of PA signals in the context of biomedical PA imaging with respect to the aforementioned aspects.
UNASSIGNED: First, we discuss the impact of laser pulse duration on the PA signal amplitude and its correlation with the lateral resolution of PA imaging. Subsequently, the relationship between the axial resolution of PA imaging and the laser pulse duration is analyzed with consideration of the acoustic frequency spectrum. Furthermore, we examine the manipulation of the pulse duration to trigger physical phenomena and its relevant applications. In addition, we elaborate on the tuning of the pulse duration to manipulate the conversion process and ratio from the PT to PA effect.
UNASSIGNED: We contribute to the understanding of the physical mechanisms governing pulse-width-dependent PA techniques. By gaining insight into the mechanism behind the influence of the laser pulse, we can trigger the pulse-with-dependent physical phenomena for specific PA applications, enhance PA imaging performance in biomedical imaging scenarios, and modulate PT-PA conversion by tuning the pulse duration precisely.

Migration of colloidal particles induced by temperature gradients is commonly referred to as thermodiffusion, thermal diffusion, or the (Ludwig-)Soret effect. The thermophoretic force experienced by a colloidal particle that drives thermodiffusion consists of two distinct contributions: a contribution resulting from internal degrees of freedom of single colloidal particles, and a contribution due to the interactions between the colloids. We present an irreversible thermodynamics based theory for the latter collective contribution to the thermophoretic force. The present theory leads to a novel \"thermophoretic interaction force\" (for uncharged colloids), which has not been identified in earlier approaches. In addition, an N-particle Smoluchowski equation including temperature gradients is proposed, which complies with the irreversible thermodynamics approach. A comparison with experiments on colloids with a temperature dependent attractive interaction potential over a large concentration and temperature range is presented. The comparison shows that the novel thermophoretic interaction force is essential to describe data on the Soret coefficient and the thermodiffusion coefficient.

Conventional Ti-based implants are vulnerable to postsurgical infection and improving the antibacterial efficiency without compromising the osteogenic ability is one of the key issues in bone implant design. Although zinc oxide (ZnO) nanorods grown on Ti substrates hydrothermally can improve the antibacterial properties, but cannot meet the stringent requirements of bone implants, as rapid degradation of ZnO and uncontrolled leaching of Zn2+ are detrimental to peri-implant cells and tissues. To solve these problems, a lattice-damage-free method is adopted to modify the ZnO nanorods with thin calcium phosphate (CaP) shells. The Ca and P ions from the CaP shells diffuse thermally into the ZnO lattice to prevent the ZnO nanorods from rapid degradation and ensure the sustained release of Zn2+ ions as well. Furthermore, the designed heterostructural nanorods not only induce the osteogenic performances of MC3T3-E1 cells but also exhibit excellent antibacterial ability against S. aureus and E. coli bacteria via physical penetration. In vivo studies also reveal that hybrid Ti-ZnO@CaP5 can not only eradicates bacteria in contact, but also provides sufficient biocompatibility without causing excessive inflammation response. Our study provides insights into the design of multifunctional biomaterials for bone implants. STATEMENT OF SIGNIFICANCE: • A lattice-damage-free method is adopted to modify the ZnO nanorods with thin calcium phosphate (CaP) shells. • The dynamic process of Ca and P diffusion into the ZnO lattice is analyzed by experimental verification and theoretical calculation. • The degradation rate of ZnO nanorods is significantly decreased after CaP deposition. • The ZnO nanorods after CaP deposition can not only sterilize bacteria in contact via physical penetration, but also provide sufficient biocompatibility and osteogenic capability without causing excessive inflammation response..

Purpose: A crucial aspect of quality assurance in thermal therapy is periodic demonstration of the heating performance of the device. Existing methods estimate the specific absorption rate (SAR) from the temperature rise after a short power pulse, which yields a biased estimate as thermal diffusion broadens the apparent SAR pattern. To obtain an unbiased estimate, we propose a robust frequency-domain method that simultaneously identifies the SAR as well as the thermal dynamics.Methods: We propose a method consisting of periodic modulation of the FUS power while recording the response with MR thermometry (MRT). This approach enables unbiased measurements of spatial Fourier coefficients that encode the thermal response. These coefficients are substituted in a generic thermal model to simultaneously estimate the SAR, diffusivity, and damping. The method was tested using a cylindrical phantom and a 3 T clinical MR-HIFU system. Three scenarios with varying modulation strategies are chosen to challenge the method. The results are compared to the well-known power pulse technique.Results: The thermal diffusivity is estimated at 0.151 mm2s-1 with a standard deviation of 0.01 mm2s-1 between six experiments. The SAR estimates are consistent between all experiments and show an excellent signal-to-noise ratio (SNR) compared to the well established power pulse method. The frequency-domain method proved to be insensitive to B0-drift and non steady-state initial temperature distributions.Conclusion: The proposed frequency-domain estimation method shows a high SNR and provided reproducible estimates of the SAR and the corresponding thermal diffusivity. The findings suggest that frequency-domain tools can be highly effective at estimating the SAR from (biased) MRT data acquired during periodic power modulation.

BACKGROUND: An intradermal nevus is a common skin tumour, and the classical method of removal has a risk of recurrence and scarring. It is a challenge for dermatologists to treat eyebrow intradermal nevi quickly and efficiently. This study focused on investigating the efficacy and safety of shearing combined with electrocautery and curettage in the treatment of eyebrow intradermal nevi.
METHODS: We describe two adult patients with eyebrow intradermal nevi treated by shearing combined with electrocautery and curettage. Both patients were followed up regularly after surgery. At follow-up, no recurrence of eyebrow intradermal nevus and no obvious scars or hypopigmentation were found in either patient. The results indicated that shearing combined with electrocautery and curettage could remove eyebrow intradermal nevus without side effects and confirmed the efficacy and safety of this modality for treating these skin lesions.
CONCLUSIONS: Shearing combined with electrocautery and curettage has superior merits, including simple operation, good cosmetic effects, and high patient satisfaction, presenting great application potential for treating intracutaneous nevus.

Herein, an n-type Ag2Se thermoelectric flexible thin film has been fabricated on a polyimide (PI) substrate via a novel thermal diffusion method, and the thermoelectric performance is well-optimized by adjusting the pressure and temperature of thermal diffusion. All of the Ag2Se films are beneficial to grow (013) preferred orientations, which is conducive to performing a high Seebeck coefficient. By increasing the thermal diffusion temperature, the electrical conductivity can be rationally regulated while maintaining the independence of the Seebeck coefficient, which is mainly attributed to the increased electric mobility. As a result, the fabricated Ag2Se thin film achieves a high power factor of 18.25 μW cm-1 K-2 at room temperature and a maximum value of 21.7 μW cm-1 K-2 at 393 K. Additionally, the thermal diffusion method has resulted in a wave-shaped buckling, which is further verified as a promising structure to realize a larger temperature difference by the simulation results of finite element analysis (FEA). Additionally, this unique surface morphology of the Ag2Se thin film also exhibits outstanding mechanical properties, for which the elasticity modulus is only 0.42 GPa. Finally, a flexible round-shaped module assembled with Sb2Te3 has demonstrated an output power of 166 nW at a temperature difference of 50 K. This work not only introduces a new method of preparing Ag2Se thin films but also offers a convincing strategy of optimizing the microstructure to enhance low-grade heat utilization efficiency.

Fused filament fabrication is one of the most desired thermal plastic additive manufacturing processes because of its ability to fabricate complex objects with high accessibility. However, due to the extrusion track-based direct write process mechanism, parts built using this method exhibit anisotropic mechanical properties. In this work, an in-process laser heating method is introduced to heal interface adhesion between adjacent deposited tracks by increasing the interface temperature to promote polymer reptation and enhance bonding strength of the interface of adjacent tracks. With the use of laser heating induced interface healing, the measured flexural strength between adjacent tracks in the same layer increased and exceeded that of the control sample tested along the track direction. The effect of laser on interface healing was also verified by investigating the load-displacement curve and morphology analysis of the fractured surface.

Since the 1920s, the Enskog solutions to the Boltzmann equation have provided a route to predicting the transport properties of dilute gas mixtures. At higher densities, predictions have been limited to gases of hard spheres. In this work, we present a revised Enskog theory for multicomponent mixtures of Mie fluids, where the Barker-Henderson perturbation theory is used to calculate the radial distribution function at contact. With parameters of the Mie-potentials regressed to equilibrium properties, the theory is fully predictive for transport properties. The presented framework offers a link between the Mie potential and transport properties at elevated densities, giving accurate predictions for real fluids. For mixtures of noble gases, diffusion coefficients from experiments are reproduced within ±4%. For hydrogen, the predicted self-diffusion coefficient is within 10% of experimental data up to 200 MPa and at temperatures above 171 K. Binary diffusion coefficients of the CO2/CH4 mixture from simulations are reproduced within 20% at pressures up to 14.7 MPa. Except for xenon in the vicinity of the critical point, the thermal conductivity of noble gases and their mixtures is reproduced within 10% of the experimental data. For other molecules than noble gases, the temperature dependence of the thermal conductivity is under-predicted, while the density dependence appears to be correctly predicted. Predictions of the viscosity are within ±10% of the experimental data for methane, nitrogen, and argon up to 300 bar, for temperatures ranging from 233 to 523 K. At pressures up to 500 bar and temperatures from 200 to 800 K, the predictions are within ±15% of the most accurate correlation for the viscosity of air. Comparing the theory to an extensive set of measurements of thermal diffusion ratios, we find that 49% of the model predictions are within ±20% of the reported measurements. The predicted thermal diffusion factor differs by less than 15% from the simulation results of Lennard-Jones mixtures, even at densities well exceeding the critical density.

In this paper, the possibility of determining the thermal, elastic and geometric characteristics of a thin TiO2 film deposited on a silicon substrate, with a thickness of 30 μm, in the frequency range of 20 to 20 kHz with neural networks were analysed. For this purpose, the geometric (thickness), thermal (thermal diffusivity, coefficient of linear expansion) and electronic parameters of substrates were known and constant in the two-layer model, while the following nano-layer thin-film parameters were changed: thickness, expansion and thermal diffusivity. Predictions of these three parameters of the thin-film were analysed separately with three neural networks. All of them together were joined by a fourth neural network. It was shown that the neural network, which analysed all three parameters at the same time, achieved the highest accuracy, so the use of networks that provide predictions for only one parameter is less reliable. The obtained results showed that the application of neural networks in determining the thermoelastic properties of a thin film on a supporting substrate enables the estimation of its characteristics with great accuracy.