Search Results (3,389)

The Manila clam Ruditapes philippinarum is a commercially important bivalve worldwide, with China being the leading producer. While the reproductive biology of this species has been extensively studied in its native or long-established ranges, knowledge of how populations cultured from non-native seed sources adapt their reproductive cycles to new environmental conditions remains limited. In this observational study, we investigated the annual reproductive cycle of a Manila clam population originating from subtropical waters (Zhejiang Province, Southern China) that was cultured in temperate aquaculture grounds in Zhuanghe Bay, Northern China. Monthly histological examination of 50 clams demonstrated that the gametogenic cycle synchronized between male and female clams. Gametogenesis started in March when seawater temperature exceeded 5.7 °C, and most gametes matured by May. A distinct bimodal spawning pattern was observed: a minor spawning event occurred from May to July, followed by a major spawning phase from September to November after a one-month gonadal recovery period in August. The condition index (CI), analyzed monthly in 30 clams, effectively reflected reproductive stages, increasing during gametogenesis and declining sharply during spawning, with its amplitude indicating spawning intensity. Seawater temperature was identified as the primary regulatory factor driving reproductive development from gametogenesis to spawning, while food availability (indicated by chlorophyll a concentration) played a crucial role in supporting gonadal recovery during summer. These results align with observations in other temperate populations, demonstrating that subtropical-origin clams can successfully acclimate their reproductive cycles to temperate environmental conditions. This study provides the first comprehensive description of the reproductive biology of transplanted Manila clams in Northern China, offering critical benchmarks for optimizing hatchery production schedules and informing sustainable fishery management practices in the region. Full article

Superconducting-qubit control is fundamentally constrained by decoherence, finite bandwidth, and hardware-limited drive amplitudes, making high-fidelity state preparation sensitive to optimizer initialization under non-convex open-system dynamics. We propose a hybrid reinforcement learning (RL)–quantum optimal control (QOC) pipeline in which a lightweight, tabular, model-free RL agent is trained offline in simulation to generate feasible, bounded seed pulses, which are subsequently refined via GRAPE under Lindblad dynamics. Hard amplitude constraints are enforced consistently across both stages, ensuring strict feasibility throughout optimization. Performance is evaluated using a budget-matched protocol based on fidelity evaluations (F-evals), enabling controlled comparison with random-start multi-start GRAPE. On a transmon-like qubit benchmark with relaxation and dephasing, RL warm-starting reduces the median online refinement effort in the adopted finite-difference GRAPE implementation from 7568 to 3543 F-evals (2.14× reduction) while achieving terminal state fidelity ≥0.995 under identical constraints and evaluation budgets. We provide a theoretical interpretation of the improvement in terms of basin-of-attraction probability shaping in constrained control landscapes and an amortized cost analysis showing that the offline RL cost is recovered after a small number of reuse cycles. The results support the view that learning-based initialization can improve warm-start quality relative to uninformed feasible multi-start in constrained open-system quantum-control benchmarks, while broader practical comparison against stronger physics-guided seeds remains for future work. Full article

This paper presents the design and multi-domain evaluation of three chaos-based excitation strategies for brushless DC (BLDC) motor drives implemented using Chua circuit-generated deterministic chaotic signals injected at three distinct control points: the PWM duty cycle, the commutation sequence, and the current feedback loop. A systematic design methodology is established for each injection architecture, including signal normalization, amplitude parameterization, and injection point characterization, evaluated across the electromagnetic, thermal, mechanical, and acoustic domains through MATLAB (R2024a) simulation and physical test stand validation. PWM injection produces controlled spectral dispersion with 5–7% speed reduction and a 10–15 dB SNR decrease, making it the recommended design choice for acoustic signature masking in stealth UAV applications. Commutation injection achieves severe system destabilization with speed reduction exceeding 56% and SNR losses greater than 30 dB, establishing it as a design tool for accelerated stress testing and fault emulation. Current feedback injection delivers a balanced excitation profile with 12–20% efficiency loss and 16–30% SNR reduction, making it suitable as a design method for online parameter identification and adaptive control development. This study establishes the first multi-domain comparative design framework for application-specific selection of chaos excitation strategies in BLDC drives, supported by nonparametric statistical validation and experimental acoustic confirmation, providing drive engineers with quantitative selection criteria across four physical domains. Full article

Background: Melanoma is one of the most dangerous types of skin cancer, with its global incidence having surged in recent years. There exists an urgent clinical need for novel therapeutic strategies that combine high efficacy, low toxicity, and multiple mechanisms of action. Methods: This study applies a “Property Optimization and Therapeutic Synergy” strategy, selecting the natural active polysaccharide component, Cordyceps polysaccharides (WCP), as a functional carrier to encapsulate the broad-spectrum chemotherapeutic agent, 10-Hydroxycamptothecin (10HCPT, HCPT). Leveraging non-covalent interactions between the two components, a self-assembly nanoscale drug delivery system (H-W NPs) with high stability and dual antitumor activity was constructed to achieve more efficient and precise antitumor effects. Results: The H-W NPs demonstrated outstanding antitumor efficacy both in vitro and in vivo. The H-W NPs achieved a threefold increase in the inhibition rate against B16-F10 cells compared to free HCPT in vitro and demonstrated a remarkable tumor inhibition rate of 95.08% in vivo. The therapeutic effect may be attributed to the dual antitumor mechanisms of the H-W NPs. Mechanistic studies revealed a synergistic dual-mode of action driving this potent efficacy. Firstly, H-W NPs efficiently induced caspase-3-mediated apoptosis in tumor cells. RNA sequencing analysis suggested the involvement of pathways related to cell cycle arrest and apoptosis. Additionally, H-W NPs promoted the expansion and activation of CD8⁺ T cells in the spleen. These activated cytotoxic T cells reinforced the apoptotic cascade, effectively amplifying the caspase-3-mediated death signal. Conclusions: In summary, the self-assembly nanoscale drug system achieved potent antitumor efficacy through the synergistic action of direct tumor cell killing and immune modulation, offering a highly promising strategy for the development of novel formulations against melanoma. Full article

Microbial community structure and its carbon, nitrogen, and sulfur metabolic potentials are playing crucial roles in biogeochemical cycles within river ecosystems. However, in karst terrain regions, the impact of the distinctive baijiu industry on these ecosystems remains incompletely understood. This study integrates hydrogeochemical and metagenomic techniques to elucidate how microbial communities and their metabolic potentials respond to the baijiu industry. The results indicate that microbial community richness was higher in the downstream section than in the upstream and core zones. Microbial network modularity decreased from 0.832 upstream to 0.439 downstream, indicating reduced network stability. The migration rate decreased from upstream to downstream, suggesting that species diffusion limitation was gradually enhanced. The NST index gradually decreased from upstream to downstream, reflecting a weakening of random processes and strengthening of deterministic processes within the community. We found significant enrichment of genes associated with dissimilatory nitrate reduction, sulfur oxidation, carbon fixation, and methanogenesis in the core zone, whereas the abundance of denitrification genes decreased. Environmental factor analysis revealed that pH, DO, and elevation are the key hydrochemical parameters driving changes in microbial community structure and metabolic functions. This study reveals the potential impact mechanisms of the baijiu industry on karst river ecosystems from the perspectives of microbial community ecology and metabolic functions, providing a scientific basis for watershed ecological conservation and sustainable management. Full article

This paper presents a thermodynamic analysis of free-turbine turboshaft engines, focusing on the quantitative distribution of turbine power and related energy parameters between the gas generator turbine and the free power turbine. The study is based on an analytical calculation model combining catalog specifications and validated experimental data, applied to a series of turboshaft engines from different manufacturers with similar free-turbine architectures and power classes ranging from approximately 960 kW to 2100 kW. The comparative analysis is conducted at take-off conditions for the engine series, while a detailed regime-dependent investigation from idle to take-off is performed for the TV2-117A reference engine. The results indicate that, at take-off, the gas generator turbine typically absorbs between 55% and 66% of the total turbine power to drive the compressor, whereas the free power turbine delivers the remaining 34% to 45% as usable shaft output. For all analyzed engines, the total actual specific enthalpy drop of the expansion process exceeds 98% of the available thermal potential, demonstrating efficient turbine energy utilization. Total turbine temperature drops are found to range between approximately 335 K and 565 K, depending on engine power class and cycle characteristics. In the case of the TV2-117A engine, the gas generator turbine power share decreases from about 75% at idle to roughly 65% at take-off, confirming a clear regime-dependent redistribution of expansion work. Thermal efficiency values at take-off vary between approximately 23% and 31% across the analyzed engine series. Unlike previous studies primarily focused on single-engine modeling or control strategies, this work introduces a unified and experimentally validated multi-engine thermodynamic framework that quantifies internal turbine power distribution patterns and provides transferable design-oriented benchmarks for free-turbine turboshaft engines. Full article

To address the core challenges of low energy utilization efficiency and limited range in front-wheel-drive electric vehicles (FWD EVs), this study proposes a dynamic series braking energy recovery strategy featuring adaptive braking force distribution and multi-factor correction. A comprehensive simulation model integrating five core modules—Cycle, Driver, Controller, Vehicle, and Display—was developed using Matlab/Simulink, combining the dynamic series recovery strategy with traditional parallel recovery strategies. Model reliability was validated through chassis dynamometer test data (maximum error ≤ 3.2%), followed by simulation comparisons under CLTC conditions. Results demonstrate that compared to parallel strategies, the dynamic series approach increases range by 25.8% (from 318 km to 400 km). Key innovations include real-time adaptive front axle braking coefficients based on braking intensity and a correction mechanism integrating vehicle speed and state of charge (SOC), achieving a balance between recovery efficiency, braking stability, and battery protection. This study provides actionable design guidance for FWD EV powertrain optimization while establishing a validated regenerative braking simulation framework. Full article

The impending Euro 7 regulation will impose strict limits on brake particulate matter (PM) emissions from new light-duty vehicles, driving manufacturers to explore alternative rotor materials and/or surface treatments. This paper evaluates the friction and wear emission performance of both a laser-clad grey cast iron (GCI) rotor surface and a plasma electrolytic oxidation (PEO) treated aluminium surface compared to that of an uncoated GCI. Tests were conducted on a small-scale tribometer rig, which was specially adapted to measure airborne emissions while emulating the standard Worldwide harmonised Light vehicle Test Procedure (WLTP). The laser-clad coating was applied via extreme high-speed laser cladding to form an initial 430 L stainless steel layer, followed by a topcoat of 80/20 vol% 430L steel/TiC, both layers being c.100 micron thick. The PEO treatment applies a c.50 micron alumina coating to both a wrought and cast alloy, the latter being more suitable for the manufacture of full-size vented brake rotors. Results show that all rotor materials achieved a satisfactory coefficient of friction (CoF) against suitable low-metallic pad material, although the CoF for the wrought PEO-Al alloy was significantly higher at c.0.65 compared with c.0.50 for the other materials. The gravimetric wear of all the coated rotor surfaces after 8 WLTP cycles was almost undetectable, and pad wear was also significantly reduced. This improved wear resistance led to significant reductions in PM emissions, with the PM10 levels of the uncoated GCI reduced by around 75% for the laser-clad GCI and PEO wrought Al alloy, and by about 60% for the PEO cast Al alloy. When extrapolated to a full-sized passenger vehicle, the results indicated that both the laser-clad GCI and PEO-treated surfaces have the potential to meet the current Euro 7 emissions targets. Full article

Fungal fairy rings (FFRs) are circular patterns primarily formed by basidiomycete fungi. These structures significantly influence grassland ecosystems by mediating nutrient cycling, altering soil microbial communities, and driving shifts in plant community composition. The present study investigates FFR formed by Agaricus xanthodermus in a Pannonian sandy grassland, with a focus on vegetation structure, productivity, and diversity. Field surveys conducted along transects across FFR quantified plant species cover, height, and additional ecological parameters. The findings demonstrate that FFR alters species dominance, reduces diversity at the ring edge, and based on ecological indicator values of plant species it increases soil nitrogen, and modify the movement of water and nutrients within the soil. Collectively, these results suggest that FFRs function as ecosystem engineers, shaping ecological processes and affecting the agricultural potential of semi-natural grasslands. Full article

Groundwater is a critical component of the terrestrial water system, and understanding the spatiotemporal evolution of national groundwater storage is essential for ensuring water security and ecological sustainability in China. Based on GRACE and GRACE-FO satellite gravity data from January 2005 to December 2024, combined with land surface water components derived from GLDAS, this study investigates the spatiotemporal variations and driving mechanisms of groundwater storage anomalies (GWSAs) across China using parametric additive decomposition, Theil–Sen trend estimation, and the Mann–Kendall significance test. The results indicate that: (1) groundwater storage in China has experienced a persistent decline at an average rate of −1.97 mm yr⁻¹, with a cumulative depletion of 38.55 mm. This decline exhibits distinct phases, characterized by a rapid decrease during 2005–2011, a moderated decline during 2012–2017, and a renewed acceleration with increased variability during 2018–2024; (2) spatially, GWSA shows a pronounced “increase in the south and decrease in the north” pattern, with extremely significant declines concentrated in the North China Plain and arid northwestern inland regions, while significant increases are mainly observed in southwestern China and southeastern coastal areas; (3) GWSA exhibits a stable seasonal cycle of “summer surplus and spring deficit,” with groundwater replenishment driven by summer precipitation and substantial depletion caused by agricultural water demand in spring; and (4) groundwater variations in northern China are primarily controlled by intensive agricultural irrigation, resulting in sustained depletion, whereas southern China is mainly influenced by natural precipitation, maintaining a relatively dynamic equilibrium. These findings provide valuable insights for region-specific groundwater management and the sustainable utilization of water resources in China. Full article

Breast cancer represents a persistent global health burden, marked by extensive molecular heterogeneity and frequent therapeutic resistance in aggressive subtypes, particularly triple-negative breast cancer (TNBC). These clinical challenges underscore the urgency for alternative therapeutic strategies. Bioactive alkaloids isolated from Nelumbo nucifera, especially the bisbenzylisoquinoline compounds liensinine (LIE), isoliensinine (ISO), and neferine (NEF), have emerged as promising candidates due to their ability to disrupt oncogenic signaling pathways and inhibit malignant cellular transformation. The present study conducted a systematic investigation of LIE, ISO, and NEF across multiple breast cancer cell lines, including highly aggressive TNBC models. Results revealed potent growth-inhibitory effects mediated through apoptosis induction and cell cycle arrest at both the G1 and G2/M phases. Furthermore, transcriptomic profiling and molecular analysis identified LIE as a principal effector, driving extensive transcriptional reprogramming and targeting the MAPK and mTOR pathways as core regulators of its anti-cancer efficacy. Collectively, these findings define a mechanistic framework for the anti-cancer potential of N. nucifera-derived alkaloids and provide a compelling foundation for their development as therapeutic candidates for advanced breast cancer. Full article

Apples in China are planted mainly in nutrient-poor mountain soil, and a large amount of fertilizer input results in resource waste and a decrease in nutrient utilization efficiency. Controlled-release fertilizer (CRF) has been shown to be environmentally friendly and increase crop yield, but nutrient release cannot be precisely synchronized with apple demand. Here, a suitable secondary fertilization method was established by a two-year apple field experiment with CRF and common compound fertilizer (CF) at various ratios under a 25% reduction in application. The application of CF and CRF changes the temporal and spatial distributions of soil NPK nutrients, decreasing NPK losses and NH₃ emissions. The NH₃ emissions under CF and CRF decreased by 17.98–44.86%, as N loss decreased by 11.59–29.81% and by 4.45–8.19%, with respect to those under CF alone, while the soil pH and electrical conductivity increased by 8.28–17.12% and 10.73–18.29%, compared with those under CF alone. The increase in soil P and K also decreased losses by 8.28–17.12% and 10.73–18.29%. The combined application of CF and CRF can increase soil microbial diversity and functional taxa and nutrient cycling genes, resulting in efficient nutrient transformation and supply for apple trees. The regulation of nutrients and microbes by the secondary application of CF and CRF drives an increase in apple yield of 23.71–54.32%, resulting in high economic benefits. In total, the application ratio of CF and CRF at 3:7 in March and July was an effective way to balance apple productivity and the soil ecological environment, providing a sustainable solution for mountainous orchard ecosystems globally. Full article

The soil–water interface (SWI) represents a critical biogeochemical hotspot where steep physicochemical gradients across millimetre-to micrometre-scales create diverse ecological niches controlling nutrient cycling, carbon stabilisation, and contaminant transformation. This review synthesises emerging understanding of micro-scale microbial dynamics, biofilm architecture, and functional processes shaping SWI ecosystems. We examine redox stratification driving microbial community assembly, biofilm-mediated nutrient trapping and soil aggregate stabilisation, and dynamic drivers including hydrological fluctuations, viral lysis, and differential transport at gas–water versus solid–water interfaces. Advanced methodologies, microsensor profiling, cryo-sectioning, spatially resolved metatranscriptomics, and non-destructive imaging, now enable unprecedented resolution of SWI microhabitat chemistry and microbial organisation. Horizontal gene transfer within interface biofilms accelerates adaptive responses to environmental stressors. Integration of micro-scale observations into ecosystem-level models remains challenging but essential for predicting soil carbon sequestration, contaminant fate, and microbial resilience under climate change. Strategic SWI management through biofilm engineering and controlled redox manipulation offers novel pathways for sustainable agriculture and bioremediation, though it requires careful balance of multiple ecosystem functions. Full article

Both gut microbiota dysbiosis and disrupted cholesterol metabolism are associated with colorectal cancer (CRC). While the interactions between these two factors have been well explored in diseases such as cardiovascular disease and atherosclerosis, their interactions and underlying mechanisms in CRC pathogenesis remain insufficiently explored, constituting a critical area for further investigation. This review examines the complex relationship between gut microbiota and cholesterol metabolism in CRC development from 2 perspectives: how specific gut microbial species can increase CRC risk by modulating cholesterol metabolism, particularly through bile acids and oxysterols, and how disrupted cholesterol metabolism can exacerbate microbial dysbiosis and promote CRC. The bidirectional relationship between gut dysbiosis and cholesterol dysregulation creates a vicious cycle that drives CRC development. Moreover, the potential of targeting the gut microbiome and cholesterol metabolism to develop new strategies for preventing and treating CRC is discussed, highlighting the promise of certain bacterial strains that exert protective effects via cholesterol-lowering mechanisms. By elucidating the intricate connections between gut microbiota, cholesterol metabolism, and CRC, this review paves the way for innovative approaches in CRC prevention and therapy. Full article

As the net gain of carbon by plants after accounting for respiration, vegetation net primary productivity (NPP) plays a central role in the terrestrial carbon cycle. However, a systematic and quantitative analysis of the spatiotemporal evolution and driving mechanisms of vegetation NPP on Hainan Island, a tropical region, is still lacking. Focusing on Hainan Island, this study employs an integrated approach—including the coefficient of variation, Mann–Kendall test, Hurst exponent, geographical detector, and PLS-SEM—to investigate the spatiotemporal dynamics of vegetation NPP and its underlying drivers from 2001 to 2022. The main conclusions as follows: (1) Vegetation NPP on Hainan Island showed a fluctuating upward trend from 2001 to 2022, with a mean annual increase of 3.6 g C·m⁻²·yr⁻¹, and displayed a spatial pattern of decrease from the central-southern mountainous areas toward the coastal regions. (2) NPP changes were generally stable; historically, areas showing an increasing trend exceeded those with a decreasing trend by 30.55%. In the future, the predominant projected trends are “persistent decrease” and “increase to decrease,” which together account for over 80% of the total area. (3) Topography and climate were the dominant drivers of NPP spatial heterogeneity. Elevation had the strongest explanatory power, followed by evapotranspiration and temperature. A significant, nonlinear enhancement effect was observed in the interaction between any two factors. (4) Topographic, climatic, anthropogenic, and vegetation factors all exerted direct positive effects on vegetation NPP. Anthropogenic activities also indirectly promoted NPP by influencing pathways such as vegetation growth. The conclusions of this research provide support for the implementation and evaluation of land-use planning, afforestation projects, and ecological protection and restoration measures on Hainan Island. Full article