Promazine Hydrochloride

Coastal ecosystems face increasing anthropogenic disturbances, making the survival strategies of phytoplankton communities under stress a critical issue in marine ecology. The community rescue theory suggests that exposure history can enhance phytoplankton's ability to withstand lethal stress, though the mechanisms remain unclear. This study utilized two-phase mesocosm experiments to simulate exposure history and lethal pressures. By combining tolerance and heritability tests, the mechanisms by which exposure history enhanced phytoplankton tolerance were investigated. The results demonstrated that: (1) Exposure history enhanced the community tolerance threshold to atrazine through ecological (the relative abundance of dinoflagellates increased by 13.6-66.4 %) and plastic processes (the EC50 of sensitive populations increased by 12.3-114.9 %). And this enhancement was positively correlated with exposure intensity but accompanied by suppression of community biomass. (2) Rescue was more likely to occur in large-scale communities, suggesting that high biomass was a prerequisite for populations/communities to survive the period of biomass collapse. Our findings aligned with the observation in in situ marine environments: long-term exposure to herbicides enhanced community tolerance (EC50 from 97.19 ± 6.8 nmol L^-1 to 115.5 ± 7.8 nmol L^-1) and delayed the collapse of communities under lethal pressure. However, this acquired tolerance was not heritable, and rescue still led to the loss of nearly half of rare taxa, potentially hindering the community's ability to withstand other environmental stressors. Our findings elucidate how phytoplankton communities achieve rescue through structural reorganization, providing crucial theoretical underpinnings for disturbance assessment in coastal ecosystems.

This work introduces an innovative method for electrochemical sensing via the creation of copper sulfide-decorated boron carbide (B₄C) nanocomposites (CuS@BC). The emphasis is on identifying sulfadiazine (SFZ), a commonly used antibiotic and environmental contaminant, often detected as a residue in water and human urine owing to its usage in beekeeping for treating bacterial infections. The existence of SFZ presents considerable hazards to vulnerable persons, highlighting the need for accurate detection techniques. The CuS was synthesized using hydrothermal technique, whereas the BC was created in a high-temperature tube furnace. This work utilizes the advanced CuS@BC nanocomposite-modified glassy carbon electrode (GCE) to examine the electrochemical detection of SFZ by differential pulse voltammetry (DPV). Thorough material characterization-incorporating Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS). A charge transfer resistance of 370 Ω was found for the CuS@BC-modified electrode by electrochemical investigation. The modified GCE exhibits exceptional electrocatalytic efficacy for SFZ electro-oxidation at appropriate physiological circumstances (pH 7.0), displaying increased cathodic currents compared with the unmodified electrode. The CuS@BC sensor has an extensive detection range of 1-110 µM and an exceptionally low limit of detection of 0.086 µM, indicating outstanding sensitivity. Displaying higher cathodic currents related to the unmodified electrode, providing outstanding selectivity, high repeatability, great reproducibility, and strong functional durability. The CuS@BC-based sensor enhances SFZ detection and shows potential for wider applications in environmental and biological monitoring.