Prymnesium parvum is a bloom forming haptophyte that has been responsible for numerous fish kill events across the world. The toxicity of P. parvum has been attributed to the production of large polyketide compounds, collectively called prymnesins, which based on their structure can be divided into A-, B- and C-type. The polyketide chemical nature of prymnesins indicates the potential involvement of polyketide synthases (PKSs) in their biosynthesis. However, little is known about the presence of PKSs in P. parvum as well as the potential molecular trade-offs of toxin biosynthesis. In the current study, we generated and analyzed the transcriptomes of nine P. parvum strains that produce different toxin types and have various cellular toxin contents. Numerous type I PKSs, ranging from 37 to 109, were found among the strains. Larger modular type I PKSs were mainly retrieved from strains with high cellular toxin levels and eight consensus transcripts were present in all nine strains. Gene expression variance analysis revealed potential molecular trade-offs associated with cellular toxin quantity, showing that basic metabolic processes seem to correlate negatively with cellular toxin content. These findings point towards the presence of metabolic costs for maintaining high cellular toxin quantity. The detailed analysis of PKSs in P. parvum is the first step towards better understanding the molecular basis of the biosynthesis of prymnesins and contributes to the development of molecular tools for efficient monitoring of future blooms.Large rivers are important terrestrial dissolved organic matter (DOM) sources to marginal seas, and dissolved organic nitrogen (DON) plays an essential role in DOM cycling. The Yellow River ranks as the fifth largest river (in length) in the world and is well-known for its high dissolved inorganic nitrogen (DIN) concentration and relatively low DON concentration, leading to extreme measuring uncertainties in DON and nitrogen isotopic composition (δ15N), consequently leaving its DON cycling as an unresolved puzzle. To fill such a knowledge gap, we analyzed 17 samples from the middle to downstream with a combination of spectroscopy, tangential flow filtration, nitrogen isotope, and DNA sequencing. DON less then 1kDa dominated the DON pool and significantly correlated inversely with DIN, indicating the DON less then 1kDa mineralized into nitrate. This finding was further supported by the observed Rayleigh fractionation in δ15NDON less then 1kDa and the spatial distribution pattern of ammonia-oxidizing bacteria/archaea abundance. The redundancy analysis revealed that the geographical features and the microbial community were closely related, which joined together to drive the DON cycling. In addition, we propose a rational method to quantify the flux of mineralized DON in large rivers. This study discovered the active DON cycling hidden in high DIN large river and highlighted the importance of DON mineralization as well as its role in marginal seas carbon cycling.Dermal sorption is an important route for human exposure to organic chemicals embedded in consumer products, but the related chemical migration from consumer products to sweats was often overlooked in assessing skin exposure risk. To address this issue, the present study selected polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), and benzothiazoles (BTs) as the target compounds and developed an in vitro simulation model with two artificial sweats (i.e., acidic and alkaline), a sorbent, and a PVC standard material. An appropriate biological inhibitor (ampicillin) and incubation time of 20 d for assessing the maximum migration efficiency of chemicals were selected. The mass balance of the target compounds during the in vitro incubation was verified. The established in vitro simulation model was used to determine the migration ratios of PAEs and BTs in three types of mouse pads. The maximum migration ratios of DBP, DIBP, DEHP, and BT from leather pad to both sweats were less than those for silicone and rubber pads. Key controlling parameters in migration ratios should be examined in subsequent investigations. Risk assessment showed that the daily exposure doses of PAEs and BTs in mouse pads were higher than the literature data. The hazard index of PAEs in leather pad exceed 1, indicating that PAEs could induce non-carcinogenic effects to human health through hand contact. Navitoclax purchase Overall, the established in vitro simulation model provides a feasible alternative for assessing the potential risk for dermal exposure to consumer products.Overcoming the relatively low catalytic activity and strict acid pH condition of common photo-Fenton reaction is the key to alleviate the serious global burden caused by common organic pollutants. Herein, a binary homologous bimetallic heterojunction of magnetic CuFe2O4@MIL-100(Fe, Cu) metal-organic frameworks (MCuFe MOF) with photothermal-boosted photo-Fenton activity is constructed as an ideal practical photo-Fenton catalyst for the degradation of organic pollutants. Through an in-situ derivation strategy, the formed homologous bimetallic heterojunction with binary redox couples can simultaneously improve the visible light harvesting capacity and expedite the separation and transfer of photogenerated electrons/holes pairs, leading to the continuous and rapid circulation of both FeIII/FeII and CuII/CuI redox couples. Notably, the heterojunction shows intrinsic photo-thermal conversion effect, which is found to be beneficial to boost the photo-Fenton activity. Impressively, MCuFe MOF shows remarkable catalytic performance towards the degradation of various organic pollutants by comprehensively increasing H2O2 decomposition efficiency and decreasing the required dosage of MCuFe MOF (0.05 g L-1) with a wide pH range (3.0-10.0). As such, a photo-Fenton catalyst consisting of binary homologous bimetallic heterojunction is first disclosed, as well as its photothermal-enhanced effect, which is expected to drive great advance in the degradation of organic pollutants for practical applications.The outbreak of COVID-19 pandemic was accompanied by global mobility restrictions and slowdown in manufacturing activities. Accordingly, cities experienced a significant decrease of CO2 emissions. In this study, continuous measurements of CO2 fluxes, atmospheric CO2 concentrations and δ13C-CO2 values were performed in the historical center of Florence (Italy) before, during and after the almost two-month long national lockdown. The temporal trends of the analyzed parameters, combined with the variations in emitting source categories (from inventory data), evidenced a fast response of flux measurements to variations in the strength of the emitting sources. Similarly, the δ13C-CO2 values recorded the change in the prevailing sources contributing to urban atmospheric CO2, confirming the effectiveness of carbon isotopic data as geochemical tracers for identifying and quantifying the relative contributions of emitting sources. Although the direct impact of restriction measurements on CO2 concentrations was less clear due to seasonal trends and background fluctuations, an in-depth analysis of the daily local CO2 enhancement with respect to the background values revealed a progressive decrease throughout the lockdown phase at the end of the heating season (>10 ppm), followed by a net increase (ca.