To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Omega-3 polyunsaturated fatty acids (PUFAs) docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), possess anti-inflammatory properties, yet their association with obesity-depression comorbidity remains unclear. This study investigated the association among US adults and explored underlying mechanisms. We performed a cross-sectional analysis of 4,423 individuals participating in the National Health and Nutrition Examination Survey (NHANES) 2003–2004 & 2011–2014. Serum fatty acids were quantified by gas chromatography. Obesity was defined using anthropometric criteria, and depression was assessed using the PHQ-9 or antidepressant use. Multivariable logistic regression estimated odds ratios (ORs) per standard deviation (SD) increase in PUFA levels. Mechanistic explore through network pharmacology identified potential pathways, which were examined using correlation analyses with inflammatory indices. Higher omega-3 PUFA levels were associated with lower odds of central obesity comorbid depression in females (OR: 0.82, 95% CI: 0.69–0.96) and older adults (OR: 0.79, 95% CI: 0.64–0.97). DHA was significantly associated with lower odds of central obesity (OR: 0.83, 95% CI: 0.73–0.95), depressive symptoms (OR: 0.88, 95% CI: 0.77–1.00), and their comorbidity (OR: 0.85, 95% CI: 0.74–0.98), whereas no significant associations were found for EPA. Mechanistic exploration implicated DHA in TNF and IL-17 signaling pathways, supported by inverse correlations with monocyte-to-HDL ratio (r: −0.138, P < 0.001) and lymphocyte-to-HDL ratio (r: −0.108, P < 0.001). In conclusion, serum DHA is inversely associated with obesity-depression comorbidity, with potential involvement of anti-inflammatory pathways. These findings underscore the potential of DHA for the management of obesity comorbid depression and the need for further interventional trials.
Prior observational studies have reported conflicting results regarding whether antidepressant treatment reduces long-term dementia risk, likely due to confounding by indication and reverse causation. We aimed to investigate the association between baseline antidepressant use and incident dementia, incorporating cognitive and neuroimaging outcomes.
Methods
We conducted a prospective cohort study using UK Biobank participants free of dementia at baseline. Antidepressant use was self-reported at baseline (2006–2010). Incident dementia was identified through linked electronic health records until December 19, 2022. Cox proportional hazards models estimated hazard ratios (HRs) for all-cause dementia, Alzheimer’s disease (AD), and vascular dementia (VD), adjusting for sociodemographic, lifestyle, health-related, antidepressant indication factors, and co-medication of other anticholinergics. In subsamples, cognitive performance (n = 57,330) and structural brain imaging (n = 42,276) were examined as intermediate outcomes.
Results
Among 461,464 participants, 33,721 (7.3%) reported baseline antidepressant use. Over a mean follow-up of 13.4 years, 7,922 (1.7%) developed incident dementia. Baseline antidepressant use was associated with higher risks of all-cause dementia (adjusted HR: 1.47, 95% CI 1.36–1.60), AD (1.53, 1.36–1.73), and VD (1.44, 1.23–1.70). Users performed worse on fluid intelligence and prospective memory tasks and showed lower total and gray matter volume, regional reductions in the hippocampal gray matter and basal nucleus, and greater white matter hyperintensity volume.
Conclusions
Baseline antidepressant use was linked to a higher risk of dementia, poorer cognitive performance, and adverse brain structural changes. These findings underscore the importance of judicious prescribing, regular cognitive monitoring, and consideration of non-pharmacological approaches in clinical care.
The performance of the wavy leading edge (WLE) on the self-noise from a cambered NACA 65(12)-10 airfoil at a Reynolds number of 100 000 is investigated in this paper. The self-noise from the airfoils is measured in an anechoic wind tunnel while the flow details are obtained from both planar particle image velocimetry measurements and the wall-resolved large eddy simulations. It turns out that the WLE is effective in reducing both the tonal and the broadband separation noise in the mid-to-low-frequency range from the baseline airfoil. The underlying mechanisms of the noise reduction are also examined carefully from both the tonal and the broadband aspects. By introducing the WLE, the generated streamwise vortices can modify the boundary-layer development and reduce the spanwise coherence of the flow structures. As a consequence, the acoustic feedback loop responsible for the tonal noise from the baseline airfoil is disturbed. Additionally, the WLE decreases the convection velocity and generates less coherent wall pressure fluctuations in the low-to-mid-frequency range, leading to broadband separation noise reduction.
Current flying-car designs lack scalability for diverse missions. This paper presents a modular design platform for developing reconfigurable flying-cars, embedding modularity across structural, electrical, and flight control domains. A full-scale sightseeing prototype demonstrates the platform’s feasibility and flexibility. The work contributes to design methodology by illustrating how modular architectures improve cross-mission adaptability, scalability, and lifecycle efficiency in complex mechatronic systems. (project introduction video available at https://www.aidilab.ai/flying-car)
Volatile organic compounds (VOCs) pose risks to human health and the environment, making the development of efficient technologies to reduce their emissions a priority. Catalytic oxidation represents a simple, efficient and environmentally friendly method for eliminating VOCs. Herein, a spinel CuCo2O4/biochar/attapulgite (ATP) composite was successfully synthesized via a sol–gel method using waste walnut shell powder as both a complexing agent and a combustion promoter. The effect of the mass ratio on toluene degradation performance was systematically investigated. The results indicated that when the mass ratio of CuCo2O4/ATP to the biomass precursor was optimized to 1:4, the catalyst exhibited excellent catalytic oxidation performance for toluene degradation, achieving 99% conversion at 300°C along with high stability. The introduction of biochar induced the formation of abundant oxygen vacancies on the spinel surface and effectively suppressed the agglomeration of CuCo2O4 particles. Moreover, the rich functional groups on biochar improved toluene adsorption, favouring the subsequent catalytic oxidation. The current study offers a cost-effective strategy for VOC abatement by taking advantage of minerals and biomass.
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.
Controlling multiphase flow in disordered media is central to diverse practical contexts. Although nanoparticles have been widely utilised to modify surface wettability, factors governing their effects on dynamic displacement patterns remain unclear. Here, we identify the criterion for nanoparticle-induced wettability alteration during displacement by combining interfacial-scale wetting models, pore-scale microfluidic experiments and simulations. Motivated by striking contrasts in static wettability, we find that nanoparticle adsorption on solid surfaces affects displacement interfaces only when spreading of wetting films is pre-established, corresponding to corner-flow conditions. Displacement experiments under varying intrinsic wettability show that wetting-film development and non-aqueous droplet detachment are strengthened exclusively on moderately water-wet surfaces satisfying the corner-flow criterion. Investigations across designed porous structures with varying degrees of structural hierarchy validate the generality of the wettability criterion, while improvement in displacement efficiency diminishes with reduced hierarchy. The structural effect arises from variations in flow heterogeneity, with stronger heterogeneity simultaneously promoting film flow and ganglion mobilisation. The coupled impacts of wettability and structural conditions are summarised in an illustrative phase diagram delineating nanoparticle-tuned multiphase displacement. Our findings offer mechanistic insights into complex fluid flow in porous media and suggest optimised strategies for displacement control via nanoparticle suspensions.
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.
The environmental effects of state ownership are still controversial. The ‘reverse privatization’ phenomenon of injecting state capital into non-state-owned enterprises offers a novel perspective to study the environmental impact of state ownership. Using data on Chinese listed companies from 2011 to 2021, this study empirically analyses the impact of state capital injections (SCAI) on firms’ green innovation. Our results reveal that SCAI has a positive effect on the quantity and quality of green innovation, reflecting the net outcome of opposing forces. SCAI promotes green innovation by enhancing firms’ innovative capabilities and willingness, increasing environmental regulatory pressure and reducing managerial myopia, though it may hinder such innovation by exacerbating agency problems and policy burdens. Moreover, SCAI’s positive effects on green innovation quantity and quality are more pronounced for firms with relatively high state capital control, in heavily polluting industries and in less marketized regions.
Recently, Alfvénic ion temperature gradient (AITG) modes have been observed in the core plasma on the HL-2A tokamak. Only when electron cyclotron resonance heating (ECRH) and neutral beam injection are simultaneously injected into the deuterium plasma do the AITG modes become unstable. The instability is electromagnetic and localised in the core plasma with an internal transport barrier. Dynamic evolution of AITG modes is greatly affected by the off-axis ECRH. Theoretical analysis suggests that there is a strong dependence of the AITG modes on $\eta _i\simeq \boldsymbol{\nabla }\ln T_i/\boldsymbol{\nabla }\ln n_i$, where $n_i$ is the ion density. It is also found that ECRH can enhances AITG modes by causing a drop of electron density and an increase of $\tau =T_e/T_i$; here $T_e$ and $T_i$ are the electron and ion temperatures, respectively. Besides, high-power ECRH may also change the safety factor or magnetic shear and then contribute to the mitigation of AITG modes. The new findings can not only enrich scientific knowledge for pressure gradient-driven instability, but also be beneficial to active control of core-localised electromagnetic modes in future fusion devices.
A combined experimental and numerical investigation was conducted to examine the mechanisms of aerodynamic noise reduction for twisted hexagonal cylinders at Reynolds numbers ($ \textit{Re} = 2\times 10^4$–$10^5$) and twist angles per unit span $\gamma ^*\in \mathbb{R}[0,1/3]$. It reveals a non-monotonic dependence of noise reduction on $\gamma ^*$, optimised for $\gamma ^* = 1/6$, where a tonal noise reduction of 15 dB and a total sound reduction of 11 dB at $ \textit{Re} = 2\times 10^4$ were achieved. This was consistent across all Reynolds numbers tested. Additionally, dual tones were observed in the noise spectra for cases with $1/18\leqslant \gamma ^* \lt 1/6$, leading to the identification of two distinct flow patterns (Pattern I and II) based on the number of tones in the spectrum. Large-eddy simulations were performed at $ \textit{Re} = 2\times 10^4$ to support the acoustic measurements. Spanwise variations in flow separation gave rise to two distinct regimes: separation (RI) and reattachment (RII). For Pattern I ($1/5.4 \leqslant \gamma ^* \leqslant 1/3$), the spanwise variation of shear layer separation induced wavy vortex shedding, contributing to a moderate noise reduction. For Pattern II ($1/18 \leqslant \gamma ^* \leqslant 1/7.2$), differences in vortex shedding frequencies between RI and RII regimes led to vortex dislocation, forming C- or X-type vortex structures. The $\gamma ^* = 1/6$ configuration leads to a transitional pattern between Pattern I and II, where modulation was predominantly observed in the RI regime. The superior noise reduction of $\gamma ^* = 1/6$ stems from the combined effects of frequent vortex dislocation and modulation, which reduces spanwise coherency and increases wake three-dimensionality.
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.
Community-acquired pneumonia (CAP) remains an important public-health problem, and the COVID-19 pandemic and non-pharmaceutical interventions (NPIs) may have altered its burden. This study aimed to provide updated CAP burden among adults in Shanghai from 2016–2023.We analysed 61,230 participants aged 20–74 years from the Shanghai Suburban Adult Cohort and Biobank. CAP episodes were ascertained via ICD codes and clinical diagnoses. We calculated incidence rates before, during, and after NPIs, conducted subgroup analyses by age, sex, comorbidity and lifestyle. We used Poisson regression to compare stages, and Cox models to identify risk factors. The Overall CAP incidence was 42.1 per 1,000 person–years (95% CI 41.3–42.8). Incidence declined during NPIs (24.2/1,000 py) and rose after NPIs (95.9/1,000 py). The inpatient-to-outpatient ratio increased to 10.1% during NPIs and fell to 5.7% post–NPI. Among those without underlying conditions, rates were 40.1, 20.1 and 73.6/1,000 py before, during and after NPIs. Incidence was higher in participants ≥60 years and in those with multiple comorbidities, especially respiratory diseases. CAP burden temporarily fell during NPIs but resurged post–NPI, notably among high–risk groups. These findings highlight the need for targeted preventive strategies and continued CAP surveillance in the post-pandemic era.
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.
MicroRNAs (miRNAs) alterations in patients with bipolar disorder (BD) are pivotal to the disease’s pathogenesis. Since obtaining brain tissue is challenging, most research has shifted to analyzing miRNAs in peripheral blood. One innovative solution is sequencing miRNAs in plasma extracellular vesicles (EVs), particularly those neural-derived EVs emanating from the brain.
Methods
We isolated plasma neural-derived EVs from 85 patients with BD and 39 healthy controls (HC) using biotinylated antibodies targeting a neural tissue marker, followed by miRNA sequencing and expression analysis. Furthermore, we conducted bioinformatic analyses and functional experiments to delve deeper into the underlying pathological mechanisms of BD.
Results
Out of the 2,656 neural-derived miRNAs in EVs identified, 14 were differentially expressed between BD patients and HC. Moreover, the target genes of miR-143-3p displayed distinct expression patterns in the prefrontal cortex of BD patients versus HC, as sourced from the PsychENCODE database. The functional experiments demonstrated that the abnormal expression of miR-143-3p promoted the proliferation and activation of microglia and upregulated the expression of proinflammatory factors, including IL-1β, IL-6, and NLRP3. Through weighted gene co-expression network analysis, a module linking to the clinical symptoms of BD patients was discerned. Enrichment analyses unveiled these miRNAs’ role in modulating the axon guidance, the Ras signaling pathway, and ErbB signaling pathway.
Conclusions
Our findings provide the first evidence of dysregulated plasma miRNAs within neural-derived EVs in BD patients and suggest that neural-derived EVs might be involved in the pathophysiology of BD through related biological pathways, such as neurogenesis and neuroinflammation.
Depression is closely associated with abnormalities in brain function. Traditional static functional connectivity analyses offer limited insight into the temporal variability of brain activity. Recent advances in dynamic analyses enable a deeper understanding of how depression relates to temporal fluctuations in brain activity.
Methods
This study utilized a large resting-state functional magnetic resonance imaging dataset (N = 696) to examine the association between brain dynamics and depression. Two complementary approaches were employed. Hidden Markov modeling (HMM) was used to identify discrete brain states and quantify their temporal switching patterns; temporal variability was computed within and between large-scale functional networks to capture time-varying fluctuations in functional connectivity.
Results
Depression scores were positively associated with switching rate and negatively associated with maximum fractional occupancy. Furthermore, depression scores were significantly associated with greater temporal variability both within and between networks, with particularly strong effects observed in the default mode network, ventral attention network, and frontoparietal network. Together, these findings suggest that individuals with higher depression scores exhibit more unstable brain dynamics.
Conclusion
Our findings reveal that individuals with higher depression levels exhibit greater instability in brain state transitions and increased temporal variability in functional connectivity across large-scale networks. This instability in brain dynamics may contribute to difficulties in emotion regulation and cognitive control. By capturing whole-brain temporal patterns, this study offers a novel perspective on the neural basis of depression.
The selection of random sampling points is crucial for the path quality generated by probabilistic roadmap (PRM) algorithm. Increasing the number of sampling points can enhance path quality. However, it may also lead to extended convergence time and reduced computational efficiency. Therefore, an improved probabilistic roadmap algorithm (TL-PRM) is proposed based on topological discrimination and lazy collision. TL-PRM algorithm first generates a circular grid area among start and goal points. Then, it constructs topological nodes. Subsequently, elliptical sampling areas are created between each pair of adjacent topological nodes. Random sampling points are generated within these areas. These sampling points are interconnected using a layer connection strategy. An initial path is generated using a delayed collision strategy. The path is then adjusted by modifying the nodes on the convex outer edges to avoid obstacles. Finally, a reconnection strategy is employed to optimize the path. This reduces the number of path waypoints. In dynamic environments, TL-PRM algorithm employs pose adjustment strategies for semi-static and dynamic obstacles. It can use either the same or opposite pose adjustments to avoid dynamic obstacles. Experimental results indicate that TL-PRM algorithm reduces the average number of generated sampling points by 70.9% and average computation time by 62.1% compared with PRM* and PRM-Astar algorithms. In winding and narrow passage maps, TL-PRM algorithm significantly decreases the number of sampling points and shortens convergence time. In dynamic environments, the algorithm can adjust its pose orientation in real time. This allows it to safely reach the goal point. TL-PRM algorithm provides an effective solution for reducing the generation of sampling points in PRM algorithm.
This study presents a novel investigation into the vortex dynamics of flow around a near-wall rectangular cylinder based on direct numerical simulation at $Re=1000$, marking the first in-depth exploration of these phenomena. By varying aspect ratios ($L/D = 5$, $10$, $15$) and gap ratios ($G/D = 0.1$, $0.3$, $0.9$), the study reveals the vortex dynamics influenced by the near-wall effect, considering the incoming laminar boundary layer flow. Both $L/D$ and $G/D$ significantly influence vortex dynamics, leading to behaviours not observed in previous bluff body flows. As $G/D$ increases, the streamwise scale of the upper leading edge (ULE) recirculation grows, delaying flow reattachment. At smaller $G/D$, lower leading edge (LLE) recirculation is suppressed, with upper Kelvin–Helmholtz vortices merging to form the ULE vortex, followed by instability, differing from conventional flow dynamics. Larger $G/D$ promotes the formation of an LLE shear layer. An intriguing finding at $L/D = 5$ and $G/D = 0.1$ is the backward flow of fluid from the downstream region to the upper side of the cylinder. At $G/D = 0.3$, double-trailing-edge vortices emerge for larger $L/D$, with two distinct flow behaviours associated with two interactions between gap flow and wall recirculation. These interactions lead to different multiple flow separations. For $G/D = 0.9$, the secondary vortex (SV) from the plate wall induces the formation of a tertiary vortex from the lower side of the cylinder. Double-SVs are observed at $L/D = 5$. Frequency locking is observed in most cases, but is suppressed at $L/D = 10$ and $G/D = 0.9$, where competing shedding modes lead to two distinct evolutions of the SV.
Schistosomiasis is a parasitic disease that imposes a significant burden on society. The eggs are the primary pathogenic factor in schistosomiasis, and their accumulation in liver could lead to the formation of granulomas and liver fibrosis. However, the metabolic changes in liver resulting from schistosomiasis remain poorly understood. We established a mouse model of schistosomiasis japonica, where the eggs accumulate in the liver and form egg granulomas. We used mass spectrometry imaging to analyze the differences in metabolites among various liver regions, including the liver tissue from normal mice, the liver area outside the granulomas in schistosomiasis mice, and the granuloma region in schistosomiasis mice. There were significant differences in metabolites between different liver regions, which enriched in metabolic pathways such as the biosynthesis of unsaturated fatty acids, taurine and hypotaurine metabolism, glycerophospholipid metabolism, glycolysis/gluconeogenesis, purine metabolism, arachidonic acid metabolism, and bile secretion. In normal liver tissue, higher concentrations of oleic acid (FA (18:1)), eicosapentaenoic acid (FA (20:5)), and L-glutamine were observed. In liver regions outside the granulomas, D-glucose and pyruvic acid were elevated compared to those in normal mice. Taurine increased in the liver of schistosomiasis. Meanwhile, there were elevated uric acid and spermidine in the egg granulomas. We employed mass spectrometry imaging technology to investigate metabolic reprogramming in liver of Schistosoma japonicum-infected mice. We explored the spatial distribution of differential metabolites in liver of schistosomiasis including unsaturated fatty acids, taurine, glutamine, spermidine, and uric acid. Our research provides valuable insights for further elucidating metabolic reprogramming in schistosomiasis.
The propagation of multiple ultraintense femtosecond lasers in underdense plasmas is investigated theoretically and numerically. We find that the energy merging effect between two in-phase seed lasers can be improved by using two obliquely incident guiding lasers whose initial phase is $\pi$ and $\pi /2$ ahead of the seed laser. Particle-in-cell simulations show that due to the repulsion and energy transfer of the guiding laser, the peak intensity of the merged light is amplified by more than five times compared to the seed laser. The energy conversion efficiency from all incident lasers to the merged light is up to approximately 60$\%$. The results are useful for many applications, including plasma-based optical amplification, charged particle acceleration and extremely intense magnetic field generation.