Hubei Academy of Environmental Sciences

Mitochondrial genome evolution(MGE) in flowering plants is quasi-intertwined-dynamic. MGE is driven via mutational pressures, translational selection, and functional constraints. However, unveiling the intra- and inter-genomic interplay governing evolutionary drives remains challenging. We investigate MGE-dynamic across twelve Gentianales species, revealing distinct codon usage patterns influenced by opposing evolutionary forces. While the first and second codon positions are highly conserved, the third codon positions show significant variability (27.7% - 45.8%), reflecting diverse selective pressures. Multi-dimensional analyses, including ENc-GC3s plots, neutrality plots, and PR2 bias, indicate that natural selection predominantly governs codon usage, outweighing mutational biases. Key findings include, non-significant correlations between GC12 and GC3 (R2 ≤ 0.21), suggesting minimal mutational impact on genome composition; ENc-GC12 analysis showing codon optimization results from both selection and mutation; and PR2-plot analysis highlighting a preference for T- and G-ending codons, indicative of translational efficiency constraints. Gene-specific analyses of substitution rates (dN, dS, and dN/dS ) uncover heterogeneous selective landscapes, with genes such as atp, ccm, nad, and rps exhibiting signatures of positive selection. Substantial mutually offsetting dynamics between T3s and C3s (r = - 0.73), coupled with strong correlations between G3s and translational-efficiency indices (CAI: r = 0.69; CBI: r = 0.65), underscore that third-codon biases optimize translation. Evolutionary rates (dS and dN/dS ) show positive correlations with GC3 content (r = 0.45 and r = 0.33, respectively), indicating the influence of nucleotide composition on synonymous substitutions. Thus, these results reveal the interplay of the mutation-selection balance in non-recombining genomes and offer new perspectives on mitochondrial diversity in flowering plants.

Most population-aggregated cities in developing countries are facing severe air pollution due to high concentrations of PM2.5 and O3, which could be associated with the impacts of local mesoscale circulations. The river land breeze (RLB) and mountain valley breeze (MVB) circulations made PM2.5 and O3 pollution causes more complicated in inland regions. By combining monitoring and simulating data from the inland region, this study analyzed the influence of local mesoscale circulations on pollutant concentrations and their underlying mechanisms. The daily average and peak concentrations of pollutants in RLB days and MVB days were different from those in non-RLB days and non-MVB days, indicating that local mesoscale circulations exerted distinct influences on regional pollutant concentrations. Moreover, hourly PM2.5 concentrations had a notable reduction during winter in RLB days when compared to non-RLB days (1.6-18.7 μg/m3), meanwhile, they increased the most during spring (1.3-7.0 μg/m3) and decreased the most during winter (2.5-14.3 μg/m3) in MVB days when compared to non-MVB days. Hourly O3 concentrations increased the least during winter in RLB days compared to non-RLB days (6.6-22.4 μg/m3), meanwhile, they showed the largest increase during spring (32.3 μg/m3) and the smallest increase during winter in MVB days compared to non-MVB days (13.2 μg/m3). Both the RLB and MVB could disperse particulate horizontally through the lower branches, with the extent of dispersion varying according to wind speeds in different seasons. The recirculation dominated by stronger branches (river/valley breezes) could enhance the formation of both O3 and secondary PM2.5 by prolonging the residence time within the region and promoting the pollutant mixing. Based on those diverse contributions, targeted management strategies will be highly desirable in regions over riverine and mountainous terrains in the inland region in Yichang, China, and similar cities around the world.

Heart failure represents the culmination of various cardiovascular diseases, distinguished by a spectrum of complex symptoms. Astragaloside IV (AST-IV) has shown significant cardiac protection in heart failure rats, though the mechanisms are not fully understood. This study aimed to investigate the effects of AST-IV using hypoxia-reoxygenation injury in cardiomyocytes and heart failure in rats to explore the effects of AST-IV. Experimental groups were treated with AST-IV, HIF-2α siRNA, or Y-27,632 (a ROCK inhibitor). Cell proliferation was assessed using CCK-8 and EdU assays, while mitochondrial membrane potential and apoptosis were evaluated using JC-1 fluorescent probes and TUNEL staining, respectively. Additionally, flow cytometry measured reactive oxygen species and apoptosis rates, with protein expressions of HIF-2α, RhoB, and ROCK determined via western blotting. Cardiac troponin I and caspase-3 levels were quantified using ELISA, and myocardial injury was examined through H&E and Masson staining. Results demonstrated that AST-IV notably increased HIF-2α and Rho/ROCK pathway protein expressions, enhancing cell proliferation, reducing apoptosis and ROS levels, but effects were partially reversible by Y-27,632 in vitro. Our findings suggest that AST-IV mitigates hypoxia-induced cardiomyocyte damage by modulating the HIF/Rho/ROCK pathway, indicating its potential as a therapeutic agent for heart failure.

China’s coastal fisheries face challenges to their sustainability due to climate and human-induced pressures on key habitat drivers. This study provides an 18-year (2003–2020) assessment of six key ecological and data-available environmental factors (sea-surface temperature (SST), salinity, transparency, currents (eastward velocity, EV; northward velocity, NV), and net primary productivity (NPP), selected for their ecological relevance and data availability, across the Bohai, Yellow, and East China Seas at a spatial resolution of 0.083°. Non-parametric trend tests and seasonal climatologies were applied using MODIS-Aqua and CMEMS data with a refined quasi-analytical algorithm (QAA-v6). The results show distinct gradients: SST ranging from 9 to 13 °C (Bohai Sea) to >20 °C (East China Sea); transparency ranging from <5 m (turbid coasts) to 29.20 m (offshore). Seasonal peaks occurred for SST (summer: 18.92 °C), transparency (summer: 12.54 m), and primary productivity (spring: 1289 mg/m2). Long-term trends reveal regional SST warming in the northern Yellow Sea (9.78% of the area), but cooling in the central East China Sea. Widespread increases in transparency were observed (65.14% of the area), though productivity declined significantly (27.3%). The drivers showed spatial coupling (e.g., SST–salinity r = 0.95), but the long-term trends were decoupled. This study provides a comprehensive and long-term assessment of multiple key habitat drivers across China’s coastal seas. The results provide an unprecedented empirical baseline and dynamic management tools for China’s changing coastal ecosystems.

An adequate food supply is a core issue for sustainable development worldwide. Amid greater instability in the food supply triggered by more armed conflicts, trade disputes, and climate change, a decline in grain cultivation area still plagues many regions. China, a major food producer globally, is a case in point. The truth is that at the moment, the formulation and implementation of policies as well as academic discussions regarding this issue are predominantly based on the sown area of grains, overlooking the fundamental role co-played by population, yield efficiency, and sown area in determining food supply. Furthermore, the commonly used indicator, the non-grain cultivation rate, fails to directly reflect the impact of the phenomenon on the grain supply. To address these gaps, this study introduces trend-change detection and factor-contribution analysis, uses long-term grain sown area data to identify regions with significant grain retreat, and quantifies the relative influence of population shifts, crop yield improvements, and sown area changes on food supply. Key findings include the following: China’s total grain production maintained steady growth from 2003 to 2023, far exceeding conventional food security thresholds. Temporary reductions in grain sown area (2015–2019, 2021–2022) were offset by rising yields, with no substantial decline in supply. Twelve provinces/municipalities, Beijing, Shanghai, Zhejiang, Fujian, Guangdong, Guangxi, Guizhou, Shaanxi, Ningxia, Sichuan, Chongqing, and Hainan, exhibited substantial declines in grain plantation. However, Sichuan and Shaanxi achieved counter-trend growth in food supply, while Ningxia and Guizhou experienced frequent fluctuations. The sown area was not always the dominant factor in per capita grain availability. Yield increases neutralized cropland reduction in Sichuan, Shaanxi, Guizhou, and Ningxia, whereas population inflows outweighed the sown area effect in the other eight provinces. The study concludes that China’s grain cropland reduction has not yet posed a threat to national food security. That said, the spatial concentration of these affected regions and their ongoing output reductions may raise domestic grain redistribution costs and intensify inter-regional conflicts over cropland protection. Meanwhile, population influx plays a similarly important role to that of grain plantation decline in the grain supply. Considering that, we believe that more moderate measures should be adopted to address the shrinkage of grain planting areas, with pre-set food self-sufficiency standards. These measures include, but are not limited to, improving productivity and adopting integrated farming. Methodologically, this work lowers distortions from normal annual cropland fluctuations, enabling more precise identification of non-grain production zones. By quantifying the separate impacts of population, crop yield, and sown area changes, it supplements existing observations on grain cropland decline and provides better targeted suggestions on policy formulation and coordination.

Nickel, as a toxic trace element in fine particulate matter (PM2.5), has detrimental effects on both air quality and human health. Based on measurements from 2020 to 2021 using a single-particle aerosol mass spectrometer (SPAMS), this study investigates the properties of nickel-containing particles (NCPs) in Guangzhou. The composition, sources, and temporal trends of NCPs were evaluated and the impact of the clean ship fuel policy introduced in 2020 was also examined. The key findings include: (1) Nickel particles account for 0.08% number fraction of PM2.5, which is consistent with previously reported mass fraction in PM2.5. (2) Three distinct types of NCPs were identified, including Ni-fresh, Ni-aged, and Ni-ash. Each type exhibits unique characteristics in size distribution, wind direction dependence, sources, and temporal variations. Ni-fresh particles originate from shipping emissions in the Huangpu Port area 2 km away and are the major contributors to fine nickel particles in the region. (3) Ni-aged and Ni-ash particles, which carry secondary components, tend to be larger (>500 nm) and are representative of regional or background nickel particles. (4) The implementation of the clean ship fuel policy has effectively reduced the number concentrations of NCPs and is beneficial to regional and local air quality.