Institutional Repository of Yantai Institute of Coastal Zone Research, CAS
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Suspended particulate matter affects the distribution and migration of heavy metals in the Yellow River
No full textSuspended particulate matter (SPM) is an important heavy metal transporter in water. As a well-known high-SPM river, its impact on the distribution and migration of heavy metals in the Yellow River (YR) deserves special attention. In this study, the spatial distributions of heavy metals in surface water and SPM of the YR were investigated. The results indicate that the concentrations (dissolved and particulate phases) and bioavailability (particulate phase) of most heavy metals were higher during the rainy season than during the dry season. A considerable proportion of heavy metals (>70 %) was transported by SPM and fine particles (clay) controlled the pollution status of heavy metals in the YR. This could lead to higher heavy metal concentrations in the SPM midstream and downstream during the rainy season and higher heavy metal concentrations in upstream during the dry season. Heavy metal adsorption experiments showed that specific combination methods (such as binding with carbonate) between Cd and SPM may cause SPM to act as a source of Cd midstream and downstream. This study provides a new perspective on the effects of SPM on heavy metal distribution and migration in the YR
Nitrogen fertilization enhances organic carbon accumulation in topsoil mainly by improving photosynthetic C assimilation in a salt marsh
No full textContinuous nitrogen (N) loading alters plant growth and subsequently has the potential to impact soil organic carbon (SOC) accumulation in salt marshes. However, the knowledge gap of photosynthesized carbon (C) allocation in plant-soil-microbial systems hampers the quantification of C fluxes and the clarification of the mechanisms controlling the C budget under N loading in salt marsh ecosystems. To address this, we conducted an N fertilization field observation combined with a 5 h 13C-pulse labeling experiment in a salt marsh dominated by Suaeda. salsa (S. salsa) in the Yellow River Delta (YRD), China. N fertilization increased net 13C assimilation of S. Salsa by 277.97%, which was primarily allocated to aboveground biomass and SOC. However, N fertilization had little effect on 13C allocation to belowground biomass. Correlation analysis showed that 13C incorporation in soil was significantly and linearly correlated with 13C incorporation in shoots rather than in roots both in a 0 N (0 g N m-2 yr-1) and +N (20 g N m- 2 yr-1) group. The results suggested that SOC increase under N fertilization was mainly due to an increased C assimilation rate and more efficient downward transfer of photosynthesized C. In addition, N fertilization strongly improved the 13C amounts in the chloroform-labile SOC component by 295.26%. However, the absolute increment of newly fix 13C mainly existed in the form of residual SOC, which had more tendency for burial in the soil. Thus, N fertilization enhanced SOC accumulation although C loss increased via belowground respiration. These results have important implications for predicting the carbon budget under further human-induced N loading
Atmospheric deposition and river runoff stimulate the utilization of dissolved organic phosphorus in coastal seas
No full textIn coastal seas, the role of atmospheric deposition and river runoff in dissolved organic phosphorus (DOP) utilization is not well understood. Here, we address this knowledge gap by combining microcosm experiments with a global approach considering the relationship between the activity of alkaline phosphatases and changes in phytoplankton biomass in relation to the concentration of dissolved inorganic phosphorus (DIP). Our results suggest that the addition of aerosols and riverine water stimulate the biological utilization of DOP in coastal seas primarily by depleting DIP due to increasing nitrogen concentrations, which enhances phytoplankton growth. This "Anthropogenic Nitrogen Pump" was therefore identified to make DOP an important source of phosphorus for phytoplankton in coastal seas but only when the ratio of chlorophyll a to DIP [Log10 (Chl a / DIP)] is larger than 1.20. Our study therefore suggests that anthropogenic nitrogen input might contribute to the phosphorus cycle in coastal seas
Physiological and transcriptomic responses of Aurelia coerulea polyps to acidified seawater conditions
No full textScyphozoan jellyfish, known for their evolutionary position and ecological significance, are thought to exhibit relatively notable resilience to ocean acidification. However, knowledge regarding the molecular mechanisms underlying the scyphozoan jellyfish response to acidified seawater conditions is currently lacking. In this study, two independent experiments were conducted to determine the physiological and molecular responses of moon jellyfish (Aurelia coerulea) polyps to within- and trans-generational exposure to two reduced pH treatments (pH 7.8 and pH 7.6). The results revealed that the asexual reproduction of A. coerulea polyps significantly declined under acute exposure to pH 7.6 compared with that of polyps at ambient pH conditions. Transcriptomics revealed a notable upregulation of genes involved in immunity and cytoskeleton components. In contrast, genes associated with metabolism were downregulated in response to reduced pH treatments after 6 weeks of withingenerational acidified conditions. However, reduced pH treatments had no significant influence on the asexual reproduction of A. coerulea polyps after exposure to acidified conditions over a total of five generations, suggesting that A. coerulea polyps may acclimate to low pH levels. Transcriptomics revealed distinct gene expression profiles between within- and trans-generational exposure groups to two reduced pH treatments. The offspring polyps of A. coerulea subjected to trans-generational acidified conditions exhibited both upregulated and downregulated expression of genes associated with metabolism. These physiological and transcriptomic characteristics of A. coerulea polyps in response to elevated CO2 levels suggest that polyps produced asexually under acidified conditions may be resilient to such conditions in the future
Optimizing an Abundance-Based Model for Satellite Remote Sensing of Phytoplankton Size Classes in the Bohai and Yellow Seas of China
No full textPhytoplankton size structure is crucial for the functionality of the ocean food web and biogeochemical cycling, serving as a key indicator for assessing the state of marine ecosystems quantitatively. Despite the development of various algorithms to quantify phytoplankton size classes (PSCs) using satellite ocean color data, their reliability in optically complex coastal regions remains uncertain and requires regional optimization. In this study, we optimized and compared typical abundance-based three-component PSC models for the Bohai and Yellow Seas (BYS) of China using an extensive in situ PSC dataset derived from pigment samples analyzed via high-performance liquid chromatography (HPLC). The optimized sea surface temperature (SST)-dependent abundance-based PSC model of the BYS (SA-PSC-BYS) generated the most accurate remotely sensed PSC datasets for the BYS and effectively reproduced the PSC patterns observed in previous in situ studies. These patterns highlight the prevalence of micro- and pico-phytoplankton at higher and lower total biomass levels, respectively, and the dominance of nanophytoplankton at the mid-range of total biomass. This reliable PSC model will be invaluable for future remote sensing studies aiming to understand the detailed spatiotemporal variability of PSCs in the BYS. Additionally, it has the potential to enhance our understanding of the trophic connections between phytoplankton size structure and fisheries, thereby facilitating the development of effective marine management strategies
Construction of a myoglobin scaffold-based biocatalyst for the biodegradation of sulfadiazine and sulfathiazole
No full textSulfonamide antibiotics, a family of broad-spectrum antibiotic drugs, are increasingly used in aquaculture and are frequently detected in aquatic environments. This poses a potential threat to organisms and may cause the evolution of antimicrobial resistance. Therefore, it is important to develop an environmentally friendly and efficient biocatalyst to degrade sulfonamides (SAs) such as sulfadiazine (SD) and sulfathiazole (ST). Here, we realized the direct and efficient degradation of SD and ST using a hydrogen peroxide-dependent artificial catalytic system based on myoglobin (Mb). The arrangements of amino acids at positions 29, 43, 64, and 68 were found to influence catalytic activity. An L29H/H64D/V68I myoglobin mutant showed the best catalytic efficiency (i.e., kcat/Km = 720.42 M-1 s-1) against SD. Next, mutant H64D/V68I showed the best degradation rate against SD (i.e., 91.45 +/- 0.16%). Moreover, L29H/H64D/V68I Mb was found to efficiently catalyze ST oxidatio
Research and improvement of cyanoacrylate on bonding properties of silicone adhesive material
No full textCyanoacrylate adhesives represent the earliest discovered and most widely utilized adhesives known to date, boasting exceptional bonding properties such as the ability to cure at room temperature, rapid curing rates, and strong adhesion. However, shortcomings persist in practical applications, notably in addressing inert materials like silicone that pose challenges for ideal adhesion. To enhance the bonding performance of cyanate ester adhesives with silicone materials, this study delves into two aspects: modifying cyanate esters and pre-treating silicone surfaces to reduce surface energy. Following internal modifications, the maximum bonding strength to silicone sheets reached 2.33 MPa, while pre-treating the silicone substrate surface enabled a maximum bonding strength of 6.10 MPa. Utilizing SEM, ATR, EDS, and other analytical techniques, the mechanisms behind the improvement in silicone substrate bonding strength are characterized, revealing changes in properties preand post-treatment. This research paves a novel path and direction for future scientific investigations and advancements in adhesive formulation and enhancement
Fatty acid esters of hydroxy fatty acids: A potential treatment for obesity-related diseases
No full textObesity, a burgeoning worldwide health system challenge, is associated with multiple chronic diseases, including diabetes and chronic inflammation. Fatty acid esters of hydroxy fatty acids (FAHFAs) are newly identified lipids with mitigating and anti-inflammatory effects in diabetes. Increasing work has shown that FAHFAs exert antioxidant activity and enhance autophagy in neuronal cells and cardiomyocytes. We systematically summarized the biological activities of FAHFAs, including their regulatory effects on diabetes and inflammation, antioxidant activity, and autophagy augmentation. Notably, the structure-activity relationships and potential biosynthesis of FAHFAs are thoroughly discussed. FAHFAs also showed potential roles as diagnostic biomarkers. FAHFAs are a class of resources with promising applications in the biomedical field that require in-depth research and hotspot development, as their structure has not been fully resolved and their biological activity has not been fully revealed
Facile fluorescence detection of malachite green in fish using molecularly imprinted polymers doped CdTe quantum dots based system
No full textMalachite green (MG) possesses high toxicity, therefore, the detection of MG in fish tissues is of vital importance. A novel core-shell MIPs doped CdTe quantum dots coated silica nanoparticles (CdTe-MIP/SiO2 NPs) were synthesized via a simple one -pot strategy. The materials were characterized carefully. The resulting CdTe-MIP/ SiO2 NPs were coated on the thin layer chromatography plate, and coupled with miniaturized fluorimeter for fluorescence detection of MG in fish samples. The resulting CdTe-MIP/SiO2 NPs based system possessed good linearity (0.01 - 20 mu mol/L), high recoveries (98.36 %-101.45 %) and low detection limit (3.7 nmol/L) for MG. Furthermore, CdTe-MIP/SiO2 NPs based system were employed to measure fish samples spiked with MG, meanwhile, HPLC was utilized to evaluate the accuracy and reliability. And the paired t -test was conducted to evaluate differences between fluorescence method and HPLC, P > 0.05 means no significant difference was observed, the results demonstrated that both fluorescence method and HPLC are suitable for MG analysis