Merkel cells, functioning as critical tactile receptors in human skin, exhibit remarkable sensitivity to light-touch stimuli, and the three-dimensional morphology of these receptors demonstrates a high adaptation to their force-field sensing functions. We propose a fluid-structure interaction (FSI) hypothesis: the characteristic short finger-like protrusions on the Merkel cell surface act as biomechanical micro-amplifiers, significantly enhancing their perception efficacy for light touch. To validate this hypothesis, we developed a micropillar array chip with biomimetic protrusion morphologies to replicate the stratified micro mechanical environment of native skin in vitro. Integrating micro-particle image velocimetry (μPIV) and finite element analysis (FEA), the research reveals that under ultra-gentle mechanical stimulation (< 1 mN), these protrusions alter local hydrodynamic characteristics by enhancing localized vorticity and shear strain, thereby functioning as micro-amplifiers for tactile signals. The results indicate that, compared to the smooth control structures without protrusions, the biomimetic microstructures with protrusions increase the local vorticity and the wall friction coefficient. This localized physical field amplification directly facilitates the effective transmission of stress to the cell membrane and its subsequent deformation. Utilizing microfluidic trapping and ultrasonic phased array stimulation, we verified at the cellular level that these amplified mechanical signals can significantly enhance the activation of Piezo channels, manifested as prominent calcium influx. This study not only elucidates the mechanism by which Merkel cell protrusions exert mechanical signal amplification through microenvironmental modulation from a micromechanical perspective, but also provides a biomimetic framework and theoretical guidance for the design of highly sensitive artificial electronic skin.
Coal-fired thermal power plants have been an important way to produce heat and power, but they account for a great proportion of anthropogenic carbon dioxide emissions, responsible for climate change. Partially replacing it with ammonia is a potential way to reduce carbon footprint while enhancing combustion characteristics. Extensive experimental and numerical investigations have been carried out on the pollutant formation, flame stability, thermodynamic, and techno-economic aspects of ammonia/coal co-firing thermal power plants, which are important to the development and application. This work aims to provide a comprehensive review of the recent progress of such a combustion strategy, advancing its practical application. First, pollutant formation, including NOx, soot, and carbon-related emissions, and control strategies, as well as mitigation mechanisms, are presented. Then, flame morphology and combustion stability, which are rarely reviewed in previous works, are analyzed in detail, along with the enhancement mechanisms. The thermodynamic performances of such combustion systems are also provided. This is followed by technical-economic analysis, including the levelized cost of energy and life cycle assessment. The main achievements of ammonia/coal co-firing are described in terms of carbon reduction, technical and economic feasibility. Future research directions, such as chemical mechanism modeling and pollutant formation interaction, are finally concluded.
Polyoxymethylene dimethyl ethers (PODE) and biodiesel, as low-carbon oxygenated fuels, can effectively improve engine combustion performance and reduce pollutant emissions. This study systematically investigates the effects of direct-injection fuel types (D100, B100 and P10D90) and PODE blending ratios (10%, 30% and 50%) on in-cylinder combustion, emission components and energy distribution of a turbocharged common-rail engine based on the single-fuel (SF) and dual-fuel (DF) modes. The results show that in both combustion modes, biodiesel (B100) exhibits the earliest ignition phase and the highest combustion pressure peak due to the high cetane number and high oxygen content. The introduction of methanol enhances the premixed combustion intensity in DF mode, and the peak values of premixed heat release rate of pure diesel (D100) and diesel-PODE (10% volume PODE, P10D90) increase by 68.40% and 64.10%, respectively. As the methanol torque substitution ratio (MTSR) increases, the combustion rate in DF mode increases, the combustion heat release process becomes more concentrated, cyclic variability intensifies, the ignition delay (ID) lengthens, and the combustion duration (CD) shortens. P10D90 has the relatively low emission levels of incomplete combustion products, especially CH3OH and HCHO emissions. When the PODE blending ratio (PBR) rises from 10% to 50%, the ID and CD in DF mode decrease by 9.19% and 4.94%, respectively, and Soot emissions in SF and DF modes decrease by 16.67% and 23.80%, respectively. With the increase of MTSR and PBR, NO2 emissions in DF mode significantly increase, the proportion of engine effective work is improved, while the exhaust losses decrease.
Postharvest losses in citrus fruit are significantly driven by Penicillium digitatum, the causal agent of green mold. Elucidating the mechanisms by which P. digitatum infects citrus can provide a theoretical basis for developing safe and effective postharvest disease control strategies. However, the key virulence factors mediating its pathogenicity remain poorly understood. Here, we identified a cerato-platanin effector, PdCP1, via a bioinformatics pipeline and confirmed its essential role in infection through overexpression assays. The secreted PdCP1 promotes pathogen virulence by inducing host reactive oxygen species accumulation and reducing defense enzyme activities, leading to oxidative damage in fruit tissues. Mechanistically, PdCP1 interacts with PdSkp1, a core component of the ubiquitin-proteasome system. This interaction is associated with the suppression of the α-linolenic acid metabolism pathway and the disruption of ROS homeostasis, thereby compromising citrus disease resistance. The present study provides new thoughts on the role and mechanism of effector protein involved P. digitatum pathogenesis.
Context Developing appropriate irrigation and nitrogen application schedules (INASs) is essential for maize production on sandy soils, where low water-retention and nutrient-holding capacities make crop performance highly sensitive to within-season water and nitrogen management. However, most crop-model-based optimization studies have focused mainly on yield and resource-use efficiency, while grain nutritional quality and the economic qualifications of optimized schedules have received less attention. Objective This study aimed to develop a CERES-Maize–NSGA-III framework to optimize INASs for shallow-buried drip-irrigated maize on sandy soil, while clarifying trade-offs among yield, crop water productivity (WPc), nitrogen physiological efficiency (PEN), and grain nitrogen concentration (GNC), and evaluate the economic performance of selected candidate schedules through partial-budget analysis. Methods CERES-Maize was calibrated and validated using two years of field observations and then coupled with NSGA-III to optimize irrigation timing, irrigation amount, nitrogen application timing, and nitrogen rate. Pareto-optimal schedules were further evaluated through candidate-schedule selection, weather-year stress testing, and partial-budget economic sensitivity analysis. Results and conclusions CERES-Maize reproduced maize growth, yield, seasonal water use, and total nitrogen uptake with acceptable accuracy. The Pareto front revealed clear trade-offs among yield, WPc, PEN, and GNC. The 16 high-yield (HY) candidates selected using the historical farmer-yield benchmark exceeded the corresponding weather-matched farmer yield in all five annual simulations and maintained positive ΔPNR across all tested price–cost combinations. Among these candidates, HY01 showed the strongest combined yield and partial-budget performance, with the highest five-year mean simulated yield (12,003.2 kg/ha) and the highest mean ΔPNR relative to the corresponding farmer-managed schedules (1307.83 yuan/ha) across the tested weather-year and price–cost combinations. In contrast, the distance-to-utopia compromise schedule produced lower yield than the corresponding farmer-managed schedule in each weather year and showed weather- and price–cost-dependent economic performance. Significance The proposed framework provides a biophysical optimization tool for generating candidate INASs and clarifying trade-offs among yield, WPc, PEN, and GNC in sandy-soil maize. Weather variability was evaluated only through ex-post simulations of selected candidates and was not incorporated directly into the optimization. Further field-level, operational, economic, and environmental validation is therefore required before practical implementation.
