Stimulated Raman scattering is a third-order nonlinear optical effect that is not only effective for wavelength converting laser output, but also for single longitudinal-mode output due to the absence of spatial hole burning. Diamond is a prominent Raman-active medium that has significant potential for linewidth narrowing and wavelength converting lasers at high power levels due to its high thermal conductivity, long Raman frequency shift and wide spectral transmission range. In this work we utilize diamond in a resonantly mode-matched external cavity to achieve cascaded Raman conversion of a 1064 nm laser. By fine-tuning the length of this external cavity, we can obtain narrow linewidth emission at 1240 and 1485 nm. When operating at maximum power, the measured linewidths were more than twofold narrower than the linewidth of the fundamental field. In addition, the noise levels of the Stokes fields are lower than that of the fundamental field throughout the entire noise frequency range, and the intrinsic linewidth of the second Stokes field, which is expressed at the hertz level (~3.6 Hz), is decreased by approximately three orders of magnitude compared to that of the pump. This work represents the first measurement and analysis of the linewidth and noise characteristics of cascaded diamond Raman lasers and, significantly, offers a new means by which high-power, narrow linewidth laser output can be produced from wavelength-converted laser systems.

An optical spectrometer system based on 60 channels of fibers has been designed and employed to diagnose light emissions from laser–plasma interactions. The 60 fiber collectors cover an integrated solid angle of $\pi$, enabling the measurement of global energy losses in a symmetrical configuration. A detecting spectral range from ultraviolet to near-infrared, with angular distribution, allows for the understanding of the physical mechanisms involving various plasma modes. Experimental measurements of scattered lights from a conical implosion driven by high-energy nanosecond laser beams at the Shenguang-II Upgrade facility have been demonstrated, serving as reliable diagnostics to characterize laser absorption and energy losses from laser–plasma instabilities. This compact diagnostic system can provide comprehensive insights into laser energy coupling in direct-drive inertial confinement fusion research, which are essential for studying the driving asymmetry and improving the implosion efficiencies.

A multifunctional optical diagnostic system, which includes an interferometer, a refractometer and a multi-frame shadowgraph, has been developed at the Shenguang-II upgrade laser facility to characterize underdense plasmas in experiments of the double-cone ignition scheme of inertial confinement fusion. The system employs a 266 nm laser as the probe to minimize the refraction effect and allows for flexible switching among three modes of the interferometer, refractometer and multi-frame shadowgraph. The multifunctional module comprises a pair of beam splitters that attenuate the laser, shield stray light and configure the multi-frame and interferometric modules. By adjusting the distance and angle between the beam splitters, the system can be easily adjusted and switched between the modes. Diagnostic results demonstrate that the interferometer can reconstruct electron density below 1019 cm–3, while the refractometer can diagnose density approximately up to 1020 cm–3. The multi-frame shadowgraph is used to qualitatively characterize the temporal evolution of plasmas in the cases in which the interferometer and refractometer become ineffective.

Soft robots show an advantage when conducting tasks in complex environments due to their enormous flexibility and adaptability. However, soft robots suffer interactions and nonlinear deformation when interacting with soft and fluid materials. The reason behind is the free boundary interactions, which refers to undetermined contact between soft materials, specifically containing nonlinear deformation in air and nonlinear interactions in fluid for soft robot simulation. Therefore, we propose a new approach using material point method (MPM), which can solve the free boundary interactions problem, to simulate soft robots under such environments. The proposed approach can autonomously predict the flexible and versatile behaviors of soft robots. Our approach entails incorporating automatic differentiation into the algorithm of MPM to simplify the computation and implement an efficient implicit time integration algorithm. We perform two groups of experiments with an ordinary pneumatic soft finger in different free boundary interactions. The results indicate that it is possible to simulate soft robots with nonlinear interactions and deformation, and such environmental effects on soft robots can be restored.

The path planning and obstacle-crossing motion planning of cable trench inspection robots are essential for achieving automated inspection. To improve path planning efficiency and obstacle navigation in complex environments, an enhanced global path planning algorithm based on the A* algorithm has been developed, combined with an improved Dynamic Window Approach (DWA) for local path planning. For unavoidable obstacles, a specific obstacle-crossing motion planning strategy has been formulated. The enhanced A* algorithm improves efficiency and safety through adaptive neighborhood expansion and the elimination of redundant path points. The improved DWA algorithm enables real-time dynamic obstacle avoidance in local path planning. The simulation results on a $20 \times 20$ grid map indicate that the improved A* algorithm reduces the number of nodes by 58.4% and shortens the path length by 6.1% compared to the traditional A* algorithm, demonstrating significant advantages over other conventional path planning algorithms. In the simulation experiments integrating global and local path planning, the enhanced A* algorithm combined with the improved DWA algorithm reduces the path length by 3.2% on the $20 \times 20$ grid map compared to the integration with the traditional DWA algorithm. On the $30 \times 30$ grid maps with different obstacle configurations, the path lengths are reduced by 3.5% and 3.6%, respectively. In the obstacle-crossing experiments, the robot successfully overcame obstacles of 10 cm and 20 cm in height. The proposed path planning algorithm and obstacle-crossing motion planning strategy hold substantial application potential in complex environments, offering reliable technical support for cable trench inspection robots.

This study conducts a numerical investigation into the three-dimensional film boiling of liquid under the influence of external magnetic fields. The numerical method incorporates a sharp phase-change model based on the volume-of-fluid approach to track the liquid–vapour interface. Additionally, a consistent and conservative scheme is employed to calculate the induced current densities and electromagnetic forces. We investigate the magnetohydrodynamic effects on film boiling, particularly examining the pattern transition of the vapour bubble and the evolution of heat transfer characteristics, exposed to either a vertical or horizontal magnetic field. In single-mode scenarios, film boiling under a vertical magnetic field displays an isotropic flow structure, forming a columnar vapour jet at higher magnetic field intensities. In contrast, horizontal magnetic fields result in anisotropic flow, creating a two-dimensional vapour sheet as the magnetic strength increases. In multi-mode scenarios, the patterns observed in single-mode film boiling persist, with the interaction of vapour bubbles introducing additional complexity to the magnetohydrodynamic flow. More importantly, our comprehensive analysis reveals how and why distinct boiling effects are generated by various orientations of magnetic fields, which induce directional electromagnetic forces to suppress flow vortices within the cross-sectional plane.

The disassembly of end-of-life lithium–ion batteries (EOL-LIBs) is inherently complex, owing to their multi-state and multi-type characteristics. To mitigate these challenges, a human–robot collaboration disassembly (HRCD) model is developed. This model capitalizes on the cognitive abilities of humans combined with the advanced automation capabilities of robots, thereby substantially improving the disassembly process’s flexibility and efficiency. Consequently, this method has become the benchmark for disassembling EOL-LIBs, given its enhanced ability to manage intricate and adaptable disassembly tasks. Furthermore, effective disassembly sequence planning (DSP) for components is crucial for guiding the entire disassembly process. Therefore, this research proposes an approach for the generation of HRCD sequences for EOL-LIBs based on knowledge graph, providing assistance to individuals lacking relevant knowledge to complete disassembly tasks. Firstly, a well-defined disassembly process knowledge graph integrates structural information from CAD models and disassembly operating procedure. Based on the acquired information, DSP is conducted to generate a disassembly sequence knowledge graph (DSKG), which serves as a repository in graphical form. Subsequently, knowledge graph matching is employed to align nodes in the existing DSKG, thereby reusing node sequence knowledge and completing the sequence information for the target disassembly task. Finally, the proposed method is validated using retired power LIBs as a case study product.

Skeletal muscle is of great importance for human activity and quality of life, as its loss contributes greatly to immobilisation, especially for aged individuals. An increased dietary intake of antioxidant vitamins may be beneficial for muscle loss because of ageing. However, the quantitative relationship between total antioxidant capacity (TAC) of antioxidant vitamins and muscle mass is undetermined. Totally, 4009 participants from the National Health and Nutrition Examination Survey (NHANES) were included. Multivariate linear regression analysis was performed with demographic, lifestyle and dietary intake adjustment factors. The dose saturation effect was also determined by a saturation effect analysis. Subgroup analysis was performed for age and sex. In the fully adjusted model, per unit increase of dietary TAC was associated with an increase of 0·018 g/kg appendicular lean mass (95 % CI 0·007, 0·029), 0·014 g/kg trunk lean mass (95 % CI 0·004, 0·024) and 0·035 g/kg total lean mass (95 % CI 0·014, 0·055). TAC was associated with a decrease of 0·004 kg/kg total percent fat (95 % CI −0·006, −0·002), 0·005 kg/kg trunk percent fat (95 % CI −0·007, −0·002) and 0·003 kg/m2 BMI (95 % CI −0·006, −0·001) at the same time. Subgroup analysis indicated that women and adults < 50 years may experience the most significant association between TAC and skeletal muscle mass. We revealed a positive correlation between TAC and lean body mass and a negative association between TAC and body fat and BMI. Saturation values were found among people aged 40–59 years. Age and sex mediate these associations.

In a horizontally heated melting system, where a solid substance is subject to melting by a warmer liquid beneath, the presence of solute in the liquid introduces a complex interplay between temperature and concentration dynamics. Employing a recently developed sharp interface method (Xue et al., J. Comput. Phys., vol. 491, 2023), we conduct direct numerical simulations to investigate the transient behaviour of the system across a broad range of Rayleigh numbers and solute concentrations. Our observations reveal distinct flow regimes: at low concentrations, the system resembles a temperature-driven melting problem, characterized by vortex rolls beneath the melting interface. As the solute concentration increases, a stably stratified layer emerges beneath the interface, leading to the transition from thermal convection to penetrative convection, which resembles those flow characteristics observed in the double-diffusive convection. This shift results from the competition between the stabilizing effect induced by solute concentration gradient and the destabilizing effect caused by temperature gradient. Otherwise in the diffusion regime, characterized by very high solute concentrations, the flow becomes static due to the complete suppression of convection by the stably stratified layer. This regime further exhibits two distinct patterns: ‘melting’ and ‘dissolution’. Beyond characterizing diverse flow patterns, our study conducts a quantitative analysis, examining heat/mass transfer, melting rates, and the evolution of temperature and concentration at the interface. These insights contribute to a better understanding of the intricate interplay between temperature and solute concentration during phase change, with implications for accurately estimating melting rates in binary fluid systems.

The buoyancy-driven motion of a deformable bubble rising near a vertical hydrophilic wall is studied numerically. We focus on moderately inertial regimes in which the bubble undergoes low-to-moderate deformations and would rise in a straight line in the absence of the wall. Three different types of near-wall motion are observed, depending on the buoyancy-to-viscous and buoyancy-to-capillary force ratios defining the Galilei ($Ga$) and Bond ($Bo$) numbers of the system, respectively. For low enough $Ga$ or large enough $Bo$, bubbles consistently migrate away from the wall. Conversely, for large enough $Ga$ and low enough $Bo$, they perform periodic near-wall bounces. At intermediate $Ga$ and $Bo$, they are first attracted to the wall down to a certain critical distance, and then perform bounces with a decreasing amplitude before stabilising at this critical separation. Periodic bounces are accompanied by the shedding of a pair of streamwise vortices in the wake, the formation of which is governed by the near-wall shear resulting from the no-slip condition. These vortices provide a repulsive force that overcomes the viscous resistance of the fluid to the departing motion, making the bubble capable of returning to the region where it is attracted again to the wall. Although periodic, the shedding/regeneration cycle of these vortices is highly asymmetric with respect to the lateral bubble displacements, vortices being shed when the gap left between the bubble and the wall reaches its maximum, and reborn only when this gap comes back to its minimum.

This study presents observations of coherent modes (CMs) in a spherical tokamak using a microwave interferometer near the midplane. The CMs within the 30–60 kHz frequency range were observed during electron cyclotron resonance heating only, and the frequency of the CMs increased proportionally with the square root of the electron temperature near $R = 0.7m$. Generally, these modes displayed bursting and chirping signatures with strong density rise and fall. Their appearance indicated an increase in the intensity of hard x rays, suggesting a deterioration in energetic electron confinement. Furthermore, the effect of CMs on the intensity of energetic electron-driven whistler waves was observed. They decreased when CMs were present and gradually increased with the decrease in CM intensity. The CMs may influence the intensity of whistler waves by affecting the energetic electron confinement.

The impact of shoaling on linear water waves is well known, but it has only been recently found to significantly amplify both the intensity and frequency of rogue waves in nonlinear irregular wave trains atop coastal shoals. At least qualitatively, this effect has been partially attributed to the ‘rapid’ nature of the shoaling process, i.e. shoaling occurs over a distance far shorter than that required for waves to modulate themselves and adapt to the reduced water depth. Through a theoretical model and highly accurate nonlinear simulations, we disentangle the respective effects of the length and angle of a shoal's slope. We investigate the effects of the shoaling process rapidness on the evolution of key statistical and spectral sea-state parameters. We let the wave field evolve over a slope with constant angle in all cases while we vary the slope length. Our results indicate that the non-equilibrium dynamics is not affected by the slope length, because further extending the slope length does not influence the magnitude of the statistical and spectral measures as long as the non-equilibrium dynamics dominates the wave evolution. Thus, the shoaling effect on rogue waves is deduced to be mainly driven by the slope magnitude rather than the slope length.

Repulsive guidance molecule b (RGMb), a glycosylphosphatidylinositol-anchored member of the RGM family, is initially identified as a co-receptor of bone morphogenetic protein (BMP) in the nervous system. The expression of RGMb is transcriptionally regulated by dorsal root ganglion 11 (DRG11), which is a transcription factor expressed in embryonic DRG and dorsal horn neurons and plays an important role in the development of sensory circuits. RGMb is involved in important physiological processes such as embryonic development, immune response, intercellular adhesion and tumorigenesis. Furthermore, RGMb is mainly involved in the regulation of RGMb–neogenin–Rho and BMP signalling pathways. The recent discovery of programmed death-ligand 2 (PD-L2)–RGMb binding reveals that the cell signalling network and functional regulation centred on RGMb are extremely complex. The latest report suggests that down-regulation of the PD-L2–RGMb pathway in the gut microbiota promotes an anti-tumour immune response, which defines a potentially effective immune strategy. However, the biological function of RGMb in a variety of human diseases has not been fully determined, and will remain an active research field. This article reviews the properties and functions of RGMb, focusing on its role under various physiological and pathological conditions.

MicroRNAs (miRNAs) play important roles in regulating salt tolerance in Dongxiang wild rice (DXWR, Oryza rufipogon Griff.). The development of salt-responsive miRNA-simple sequence repeat (SSR) markers will significantly bolster research on DXWR, providing novel tools for exploring salt-tolerant genetic resources and advancing the development of salt-tolerant rice varieties. In the present study, a total of 137 miRNA-SSR markers were successfully developed, specifically derived from miRNAs responsive to salt stress in DXWR. Subsequently, a subset of 20 markers was randomly selected for validation across three distinct DXWR populations, along with 35 modern rice varieties. Notably, 13 of these markers exhibited remarkable polymorphism. The polymorphic markers collectively amplified 52 SSR loci, averaging four alleles per locus. The polymorphism information content values associated with these loci spanned from 0.23 to 0.70, with a mean value of 0.49. Particularly noteworthy is the miR162a-SSR marker, which demonstrated distinct allelic patterns and holds potential as a diagnostic marker for discriminating the salt-tolerant rice varieties from the non-tolerant varieties. This study provides a valuable tool for genetic analysis and precision breeding, facilitating the identification and utilization of valuable salt-tolerant genetic resources.

MicroRNAs (miRNAs) are endogenous, non-coding RNAs, which are functional in a variety of biological processes through post-transcriptional regulation of gene expression. However, the role of miRNAs in the interaction between Bacillus thuringiensis and insects remains unclear. In this study, small RNA libraries were constructed for B. thuringiensis-infected (Bt) and uninfected (CK) Spodoptera exigua larvae (treated with double-distilled water) using Illumina sequencing. Utilising the miRDeep2 and Randfold, a total of 233 known and 726 novel miRNAs were identified, among which 16 up-regulated and 34 down-regulated differentially expressed (DE) miRNAs were identified compared to the CK. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that potential target genes of DE miRNAs were associated with ABC transporters, fatty acid metabolism and MAPK signalling pathway which are related to the development, reproduction and immunity. Moreover, two miRNA core genes, SeDicer1 and SeAgo1 were identified. The phylogenetic tree showed that lepidopteran Dicer1 clustered into one branch, with SeDicer1 in the position closest to Spodoptera litura Dicer1. A similar phylogenetic relationship was observed in the Ago1 protein. Expression of SeDicer1 increased at 72 h post infection (hpi) with B. thuringiensis; however, expression of SeDicer1 and SeAgo1 decreased at 96 hpi. The RNAi results showed that the knockdown of SeDicer1 directly caused the down-regulation of miRNAs and promoted the mortality of S. exigua infected by B. thuringiensis GS57. In conclusion, our study is crucial to understand the relationship between miRNAs and various biological processes caused by B. thuringiensis infection, and develop an integrated pest management strategy for S. exigua via miRNAs.

Immunity activation and inflammation are the main characteristics of rheumatoid arthritis and clonal hematopoiesis. However, it remains unclear whether rheumatoid arthritis increase the risk of clonal hematopoiesis. Here, a Mendelian randomization (MR) analysis was conduct to explore the causal effects of rheumatoid arthritis on clonal hematopoiesis. Summary statistics data of rheumatoid arthritis (13,838 cases and 33,742 controls) and clonal hematopoiesis (10,203 cases and 173,918 controls) derived from a genomewide association study were selected to analyze. We selected inverse-variance weighted, MR-Egger, weighted median, simple mode, and weighted mode to evaluate the causal effect of rheumatoid arthritis on clonal hematopoiesis. The two-sample MR analysis suggested a strong causal relationship between rheumatoid arthritis and clonal hematopoiesis by inverse-variance weighted (OR = 1.002311673, 95% CI [1.000110757, 1.004517433], p = .039706) and weighted median (OR = 1.002311673, 95% CI [1.000110757, 1.004517433], p = .039518447) methods. No significant pleiotropy or heterogeneity was found in the sensitivity analysis. These results supported a potentially causal relationship between rheumatoid arthritis and clonal hematopoiesis, and the exposure of rheumatoid arthritis increased the risks of clonal hematopoiesis. Our findings highlight the importance of how chronic inflammation and immune activation induced rheumatoid arthritis enhances the risks of clonal hematopoiesis, and that early intervention with rheumatoid arthritis patients might reduce the clonal hematopoiesis risks in rheumatoid arthritis patients. Moreover, our study provides clues for prediction of risk factors and potential mechanisms of clonal hematopoiesis.

In the double-cone ignition scheme of inertial confinement fusion, the head-on collision of two compressed fuel jets from the cone-tips forms an isochoric plasma, which is then heated suddenly by a MeV relativistic electron beam produced by ultra-intense picosecond laser pulses. This fast-heating process was studied experimentally at the Shenguang II upgrade laser facility. By observing temporal-resolved X-ray emission and the spatial-resolved X-ray spectrum, the colliding process and heating process are carefully studied. The colliding plasma was imaged to have dimensions of approximately 86 μm in the implosion direction and approximately 120 μm in the heating direction. By comparing the simulated plasma X-ray spectrum with experimental data, the electron temperature of the heated plasma was found to rapidly increase to 600 ± 50 eV, almost doubling the temperature achieved before the heating laser incidence.