The spiral structure of interventional robots is widely utilized for vascular dredging procedures. Variations in the spiral structural parameters of these robots exert a significant impact on the hemodynamic parameters within the vessel during the interventional process; therefore, optimizing the design of these parameters constitutes a crucial prerequisite for ensuring safe diagnosis and treatment. Based on the bidirectional fluid-structure interaction (FSI) between pulsatile blood and elastic blood vessels, theoretical calculations and experimental measurements of the fluid velocity inside the vessel during robotic intervention were conducted. The results demonstrate that the trends and magnitudes of the calculated values are essentially consistent with those of the measured values. Furthermore, the range and variance methods in orthogonal design were applied to numerically investigate the effects of three key spiral parameters – spiral pitch, spiral groove depth, and thread profile – on hemodynamic and vascular parameters, including blood velocity, blood pressure, vascular wall shear stress, and vessel deformation. The findings indicate that spiral groove depth is the primary and most significant factor influencing blood velocity, blood pressure, and vessel deformation. In contrast, spiral pitch emerged as the main and critical factor affecting vascular wall shear stress. Meanwhile, thread profile is found to be a secondary factor with relatively minor impacts on all the aforementioned parameters. To achieve the objective of safe interventional diagnosis and treatment, it is recommended that the robot’s spiral structure be designed with a smaller spiral groove depth, a moderate spiral pitch, and a thread profile featuring strong cutting capability.

This work aims to investigate experimentally the control of a turbulent boundary layer over a flat plate based on a genetic-algorithm (GA)-based control system. A novel actuator is developed in house, consisting of one array of 11 spanwise-aligned synthetic minijets through longitudinal miniature slits, each independently controlled in terms of its exit momentum coefficient Cμ, frequency fe and phase ϕ, while nine wall wires are placed downstream of the actuator to measure a variation in wall friction. A GA is employed for the unsupervised learning of near-optimal control strategies, i.e. the optimal ϕ of the synthetic jets, with fe and Cμ optimized first. The learning process unveils three typical control strategies that may attain substantial drag reduction (DR) in both actuation and downstream regions, i.e. conventional uniform forcing (CUF), GA-I and GA-II. The latter two are characterized by the triangle- and trapezoid-like distributions of ϕ, respectively, thus each producing a spanwise motion. The three strategies achieve spanwise-averaged local DR by 45 %, 52 % and 52 %, respectively. The downstream drag-reducing areas exhibit an appreciable difference between the three cases, with CUF recovering drag more rapidly than the other two. It has been found that the three cases are associated with different DR mechanisms and flow physics, which account for the distinct control performances.

Boundary layer ingestion (BLI) propulsion can improve aircraft aerodynamic efficiency, but also introduces inlet distortion that affects fan flow and stability. This study investigates the resulting unsteady flow response and loss mechanisms by performing a parallel comparison of unsteady Reynolds-averaged Navier–Stokes (URANS) and large-eddy simulation (LES) under unified geometry and boundary conditions, together with a time-sequence analysis of three representative LES instants. The results show that, compared with URANS, LES provides a more detailed depiction of the distortion pattern and internal vortical structures. LES captures the generation and mixing of fragmented vortex systems, and reveals corner separation near the stator hub and the decay of throughflow capacity, identifying major internal loss sources. The time-sequence comparison further shows that, although the distorted vortex core evolves in strength and shape, its circumferential phase remains essentially preserved, leading to a stable distorted sector at the aerodynamic interface plane. Within this sector, the rotor approaches critical incidence and triggers local separation, while the stator passages exhibit a sector-fixed, circumferentially continuous loss distribution. These findings clarify distortion-induced unsteady loss mechanisms in BLI fans and provide numerical guidance for locating loss regions and supporting distortion-tolerant design of intake–fan integrated systems.

The species of Pavo and Afropavo are known as peafowl, and they occupy a disjunct distribution in southern Asia and central Africa. This distinct geographic distribution has led to debate regarding the origin and evolution of this clade, and the current fossil record of peafowl extends into the Neogene of Europe, Asia, and Africa, pointing to a more recent origin of the disjunction. Here we describe an associated partial skeleton from late Miocene deposits in the Linxia Basin, China, at the edge of the Tibetan Plateau, representing a new extinct bird taxon, Eopavo hezhengensis n. gen. n. sp. The holotype is represented by parts of the limbs, synsacrum, pelvis, pectoral girdle, and vertebrae. Morphological comparisons and a phylogenetic analysis place this extinct species as the closest relative of Pavo and Afropavo, nested within the clade Pavonini. Eopavo hezhengensis has a relatively longer spur given its smaller body frame, likely indicating that the holotype specimen derives from a male individual and that this species possibly participated in aggressive, physical contact between conspecific males as some relatives do today. The small body size of Eopavo may be linked to its occupation of a high-elevation Miocene savanna habitat, which is different from the humid forest preferred by its extant relatives. Along with older fossil peafowl records in the Himalayan area dated to 13.6 Ma, Eopavo hezhengensis helps to document the diversity and ancient history of the peafowl clade in Asia, and it indicates that peafowl dispersed from Asia to other continents during the late Miocene and Pliocene, with the Tibetan Plateau as a potential center of origin.

UUID: http://zoobank.org/44294174-a06f-487c-b566-d466fafd6165

We investigate experimentally the flow structure in a fluid layer of thermal conductivity $k$, heated from below with a uniform heat flux $F$, and exposed to a horizontal temperature gradient, $\lambda$, on the top plate. This is a model system for the dynamics in subglacial lakes where such a competition between Rayleigh–Bénard convection (RBC) and horizontal convection (HC) is thought to happen. We evidence a hysteretic transition from a RBC flow structure to a HC flow structure when the non-dimensional control parameter, $\varLambda = k\lambda /F$, is $4\times 10^{-4}$ when $\varLambda$ is decreasing, and $7\times 10^{-4}$ when $\varLambda$ is increasing. These values are lower than the threshold value found in recent two-dimensional direct numerical simulations (Couston et al. 2022 J. Fluid Mech., vol. 947, p. A13), of order $10^{-2}$, highlighting the importance of exploring three-dimensional dynamics at higher realistic Prandtl numbers, and suggesting that HC may be more common in subglacial lakes than previously predicted. For large values of $\varLambda$, we observe that the warmest part of the top plate has approximately the same temperature as the bottom plate, such that a stable temperature gradient settles below the warm side of the top plate. Thermal plumes are no longer visible in this region, and seem to be replaced by internal gravity waves.

The objective of this study was to investigate the gene-breastfeeding interaction on BMI based on the Chinese National Twin Register (CNTR). The study included 4,573 pairs of same-sex twins aged 2–18 from CNTR. Data were collected using a self-reported questionnaire, and a structural equation model was used to analyze the gene-environment interaction of breastfeeding with BMI in six age groups. Our findings indicate that as age increases, the heritability of BMI shows an increasing trend, being the lowest (h2: 0.08; 95% CI [0.00, 0.19]) in the 6- to 8-year age group and the highest (h2: 0.57, 95% CI [0.44, 0.72]) in the 12- to 14-year age group. Additionally, breastfeeding significantly modified the additive genetic component of BMI in the 6- to 8-year age group and 12- to 14-year age group. In the 6- to 8-year age group, breastfeeding decreased the impact of genes on BMI, with a genetic effect modification coefficient (βa) of −0.19 (−0.25, −0.13). In the 12- to 14-year age group, breastfeeding increased the impact of genes on BMI, with a genetic effect modification coefficient (βa) of 0.08 (0.02, 0.15). In conclusion, as age increases, the genetic influence on children’s BMI becomes more pronounced. Breastfeeding may modulate genetic effects at the ages of 6–8 and 12–14. Given the metabolic diversity of obesity, our findings offer insight into how breastfeeding interacts with genetic background, helping to unravel the complex gene–environment interplay influencing obesity.

Multi-plane light conversion (MPLC) is a versatile technique that enables arbitrary manipulation of optical fields, and is numerically investigated as a novel avenue for coherent beam combining (CBC) applications. The optical parameters have been investigated to guide the MPLC design, indicating that the number of phase planes and plane spacing serve as pivotal factors. The channel scalability is simulated, revealing that the plane spacing should be increased in a larger array to maintain high performance under a few-plane limit. CBC of up to 1027 lasers has been numerically demonstrated with near-diffraction-limited beam quality (M2 of 1.16 and combining efficiency close to 100%) with only seven phase plates. Beam steering is investigated, revealing that steering capability is related to both the number of multiplexed modes in MPLC and their mode fidelities, and the main-lobe power ratio of 87.1% at one divergence angle is achieved in a 10-mode MPLC with five phase plates.

Dietary intervention represents a promising strategy for managing post-surgical patients with Crohn’s disease (CD). This study aims to evaluate the effects of a modified Mediterranean diet (MMD) supplemented with partial enteral nutrition (PEN) for 4–5 weeks on quality of life in post-surgical CD patients, compared with exclusive enteral nutrition (EEN). The study was conducted at The Second Affiliated Hospital of Zhejiang University School of Medicine. The primary outcome was quality of life, measured using the 22-item inflammatory bowel disease quality-of-life questionnaire (IBDQOL-22) at the end of the intervention. Secondary outcomes included nutritional status and disease-related characteristics. Among 115 screened patients, forty-six were randomised to either the EEN group (n 24) or the MMD supplemented with PEN group (n 22). Twenty-three patients in the EEN group and twenty-two in the MMD supplemented with PEN group completed the study and were included for analysis. At the end of the intervention, both groups achieved similar 22-item inflammatory bowel disease quality-of-life questionnaire (IBDQOL-22) scores (EEN v. MMD supplemented with PEN: 88·43 (sd 9·17) v. 87·57 (sd 7·38), P = 0·734). In addition, both groups exhibited comparable nutritional status and disease-related characteristics (all P > 0·05). These results suggest that MMD supplemented with PEN provides comparable clinical benefits to EEN in post-surgical CD patients and may serve as an alternative nutritional strategy.

Dysregulation of fatty acids metabolism has been associated with the risk of osteoarthritis (OA), yet current evidence from epidemiological or genetic studies remains inconclusive. We aimed to investigate the phenotypic association and genetic architecture between total fatty acids, saturated fatty acids (SFA), MUFA, PUFA and OA. Leveraging individual-level data from the UK Biobank, combined with the hitherto largest genome-wide association studies of fatty acids (n 136 016) and OA (n 826 690) in European individuals, we implemented a comprehensive analytical framework. This included observational and genetic analyses, incorporating phenotypic associations, genetic correlations, cross-trait meta-analysis, enrichment analysis and Mendelian randomisation (MR). Observational analysis identified SFA as a risk factor, while MUFA and PUFA as protective factors for OA. Despite a lack of genome-wide genetic correlation, statistically significant local signals were detected within three specific genomic regions. Cross-trait meta-analysis identified sixty-eight pleiotropic loci shared between fatty acids and OA, of which nine were novel. Enrichment analysis revealed the shared genes were enriched in lipoprotein metabolism, immune response and inflammation regulation pathways. Two-sample MR provided evidence for a causal relationship of MUFA and PUFA on OA that survived false discovery rate correction. This study supports associations between circulating fatty acids and OA, with MUFA and PUFA exerting a protective role. Our findings provide new perspectives into OA prevention especially regarding the potential dietary interventions.

Precise control of the polarization of X-ray lasers is crucial in broad applications such as ultrafast-physics experiments and material characterization. Existing X-ray polarization converters, however, are mainly suited for low-power conditions and usually suffer from either large size or low conversion efficiency. Here we propose a compact and efficient scheme for polarization conversion of high-power, high-intensity femtosecond X-ray lasers, based on linear total internal reflection at the interface of the vacuum and solid-density plasma plate. Particle-in-cell simulations show that although the reflectivity is affected by the density oscillations of the surface plasma waves that are inevitably excited, the single-pass reflectivity can still exceed 95% and approach 100% for a broad range of laser parameters. Beyond its high conversion efficiency and damage resistance, this method offers dynamic tunability and enables ultrafast polarization switching (sub-ps), positioning it as a compact and innovative solution for polarization control in high-power X-ray laser systems.

In view of the post-stroke finger contracture period, the patient’s muscle weakness causes the fingers to bend and not be extended, and the fingers are in a contracture state. A new hand rehabilitation exoskeleton with a cable and leaf spring hybrid drive is designed. The high-stiffness leaf spring helps the patient complete the extension movement, and the flexion and grasping movement is completed under the action of the cable. The exoskeleton combines the cable and the leaf spring in the driving form. It is flexible and can generate enough grasping force to meet daily activities. The workspace when wearing the exoskeleton is analyzed, and the simulation verifies that the exoskeleton has a high movement space. The stiffness of the finger module is analyzed to determine the appropriate size parameters of the leaf spring. The experimental prototype is built, and the structural performance test is carried out. A prosthetic hand model is made to simulate the hand of a patient without motor ability. The position control is carried out to complete the gesture experiment and grasping experiment, which verifies that the exoskeleton can meet the rehabilitation needs and daily grasping movements. Finally, a variety of performance parameters are designed to evaluate a variety of exoskeletons. The comparison shows that the exoskeleton in this paper has significant advantages, and the area coverage rate of the performance evaluation map can reach 70.4% of the ideal exoskeleton.

We examine the dynamic interactions between the large-scale coherent motion and the small-scale turbulence in the passive scalar field of a circular cylinder wake, where the coherent motion exhibits strong periodicity. A combination of four X-wires and four cold wires was used to simultaneously measure the three velocity and temperature fluctuations at nominally the same location. Measurements were taken at $x/d=10$, 20 and 40 in the mean shear plane at Reynolds number 2500, based on the cylinder diameter $d$ and the free-stream velocity. The phase-averaging technique is used to distinguish the large-scale coherent motion from the stochastic motion, enabling the construction of phase-averaged structure functions of the passive scalar in the scale phase plane. The maximum of the coherent scalar $\tilde {\theta }$ closely aligns with the minima of the phase-averaged strain $\langle S \rangle$ and the vortex centre, suggesting that heat is contained within the interior of the vortex. The scale-by-scale distributions of the scalar variance and the streamwise velocity variance exhibit a similar phase dependence associated with the coherent motion. This dependence is perceptible even at the smallest scales. However, as the distance from the cylinder increases, the perceivable scale range decreases and eventually disappears. An expression is formulated to describe the time-averaged second-order structure function of coherent scalar and the time-averaged second-order mixed structure function between the coherent scalar and coherent streamwise velocity at $x/d= 10$ and 20, where the coherent motion is prominent. Furthermore, the scale-by-scale contribution of the coherent scalar variance to the total scalar variance is evaluated. Also, we derive the scale-by-scale scalar variance transport equations that account for the coherent motion in both general and isotropic formulations. Assuming local isotropy, it is found that the equation agrees approximately with the experimental data across all scales at $x/d= 40$. Finally, the differences between the scale-by-scale transport equation for the stochastic scalar variance and that for the stochastic turbulent kinetic energy are discussed.

Conceptual improvements are a significant dimension through which local moral progress occurs, both at the individual and societal levels. Michele Moody-Adams (1999) offers a narrow view of moral progress, suggesting that only a deepened understanding of complex, existing moral concepts can constitute moral progress. Consequently, she views the role of moral philosophy as limited to constructing deeper accounts of these concepts. We broaden Moody-Adams’s (1999) account by identifying three distinct types of conceptual improvements that can constitute moral progress: deepening the understanding of existing concepts, creating new concepts, and enhancing the ability to apply concepts. We support this typology with historical examples where such improvements constituted moral progress. Based on this typology, we argue that the role of moral philosophy extends beyond developing and refining moral theories to include the active creation of new concepts and the facilitation of conceptual application.