The COVID-19 pandemic has become a long-term crisis that calls for long-term solutions. We combined an augmented SEIR simulation model with real-time human mobility data to decompose the effects of ...lockdown, travel bans and effective testing measures in the curtailment of COVID-19 spread in China over different time horizons. Our analysis reveals that the significant growth in the detection rate of infectious cases, thanks to the expansion in testing efficiency, were as effective as city lockdowns in explaining the reduction in new infections up to mid-March. However, as we extended the analysis to July, increasing the detection rate to at least 50% is the only reliable way to bring the spread under control.
•Combing usage of QuEChERS and DLLME for the determination of neonicotinoid residues in grains.•Smart role of water as extractant in QuEChERS and as external phase in DLLME.•Extraction relay using ...MeCN after water in QuEChERS and successive play of MeCN as dispersant in DLLME.•Comprehensive consideration of the single factor test and response surface method to optimize parameters.•Good sensitivity, precision, and applicability of the developed method for real grains samples.
Monitoring neonicotinoid residues in grains is of significant interest for the proper assessment of pesticide exposure to human. The quick, easy, cheap, effective, rugged, and safe extraction method combined with dispersive liquid-liquid micro-extraction (QuEChERS-DLLME) was developed for extracting, purifying, and concentrating seven common neonicotinoid pesticides from the grains (rice, millet, and maize). Water and acetonitrile were used in tandem as extractants in QuEChERS, while water, acetonitrile, and trichloromethane in DLLME acted as the external phase, dispersant, and extractant, respectively. Comprehensive consideration of the single factor test and response surface method to optimize parameters including type and volume of extractants and dispersant. The evaluation showed that the QuEChERS-DLLME method held excellent linearity (R2 > 0.99). The limits of quantitation ranged from 0.003 to 0.08 µg kg−1 for the seven insecticides. The recoveries were in the range of 62–118%, and good reproducibility was obtained with a relative standard deviation below 15%.
Disinfection byproducts (DBPs) remains an ongoing issue because of their widespread occurrence and toxicity. Various organic substances in Algogenic organic matter (AOM) can produce DBPs in the ...chlorination process. To provide specific suggestions for the targeted removal of DBP precursors in AOM, the main biochemical components in AOM were qualitatively and quantitatively analyzed. An accurate model for predicting the DBP formation potentials (DBPFPs) of AOM was herein developed based on the dissolved organic carbon of the five main biochemical components in AOM and the DBPFPs of their corresponding surrogates. The contributions of each biochemical component to the three DBP species were evaluated, and the key components were identified. The results showed that lipids, proteins, carbohydrates, humic acid-like substances, and fulvic acid-like substances were the main biochemical components in AOM. Thereof, proteins (71.2 ± 2.1%) and carbohydrates (53.1 ± 2.1%) were the major contributor to the carbon content in intracellular organic matter and extracellular organic matter, respectively. The contribution results of biochemical components to the formation of DBPs showed that proteins were the key contributor to DBPs, suggesting that the targeted removal of proteins before the chlorination process would effectively reduce DBPs from AOM.
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•Carbon contents of biochemical components in AOM were first determined.•Main biochemical components in AOM were qualitatively determined.•Proteins and carbohydrates were the major biochemical components in AOM.•Proteins in AOM were the key contributor to DBPs during chlorination of AOM.
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•Twenty-nine DBPs including nitrosamines were investigated in swimming pools.•The risk assessment of nitrosamines in pool water was reported firstly.•The reliability of using THMs as ...the sole standard for DBPs was discussed.•The multivariate regression model for DBP concentrations was developed.
Disinfection is an indispensable water treatment process used to inactivate pathogens and prevent outbreaks of infectious diseases in swimming pools. However, toxic disinfection byproducts (DBPs) are inevitably formed during the process. To improve the supervision and regulation of DBPs in swimming pools, the reliability of using trihalomethanes (THMs) as the sole indicator of organic DBPs and the possibility of using easily detectable water quality parameters as predictors of DBPs were discussed based on the occurrence of 29 typical DBPs in swimming pools. Among the target DBP categories, THMs and haloacetic acids (HAAs) were the prominent species, and the concentrations of HAAs were the highest. The risk assessment results indicated that the total risk values in most pools were higher than the acceptable value (10−6). Compared with nitrosamines and THMs, HAAs were the main contributors to the cancer risks posed by dermal absorption and ingestion. THMs (r = 0.619; p < 0.01) and HAAs (r = 0.989; p < 0.01) were both significantly correlated with total DBPs (the sum of 29 DBPs). A stepwise multivariate regression model was developed by analyzing the correlations between total DBPs and water quality parameters, and the relationship coefficient R2 was 0.756. This study provides important information and perspectives for the improvement and implementation of standards for swimming pool water.
•Degradation of clofibric acid (CA) was studied by UV/PS and UV/chlorine.•The second-order rate constants of CA with SO4−, OH and Cl were determined.•Impacts of different conditions including oxidant ...dosage, pH, Cl− and HCO3− were discussed.•UV/chlorine was found to be more cost-effective.•The disinfection by-products (DBPs) formation was evaluated during followed chlor(am)ination.
This study investigated the UV/persulfate (UV/PS) and UV/chlorine processes as alternative method for the removal of clofibric acid (CA). The formation of disinfection byproducts (DBPs) during subsequent chlor(am)ination was also evaluated. The degradation of CA followed the pseudo-first order kinetics. The second-order rate constants of CA with SO4−, OH and Cl were respectively determined as kSO4-,CA=(1.73±0.01)×109M−1s−1, kOH,CA=(2.72±0.08)×109M−1s−1 and kCl,CA=(9.76±0.15)×1010M−1s−1. The degradation rate constant increased with increasing oxidant dosage in UV/PS and UV/chlorine processes. The degradation rate constant was found to be the highest at pH 9 and decreased dramatically at pH 11 in UV/PS process. For UV/chlorine, the rate constant continuously decreased with increasing pH from 3 to 11. Presence of HCO3− and Cl− had different effects (promotion and/or inhibition) on CA degradation in both processes. An inhibition effect was observed in the presence of NOM for the two UV-based processes. The higher CA removal in real water suggested the two processes were suitable for treating water containing CA, and the UV/chlorine was more cost-effective than UV/PS based on the total cost of electrical energy. Compared with the chlor(am)ination of CA, the UV/PS and UV/chlorine pre-oxidation significantly impacted the DBP formation during subsequent chlor(am)ination, which indicated the application of the two UV-based processes needs to be carefully balanced against the downstream effect on DBP formation.
This research aims to identify the hub genes associated with the senescence of triploid caudal fin cells. Transcriptomic data are obtained from the high and low generation (P6, P60) of triploid ...crucian carp caudal fin cells by high-throughput sequencing technology. Initially, all differential genes between the high and low generations are screened, yielding 4140 significantly upregulated genes and 3724 significantly downregulated genes. Subsequently, an aging gene set containing 950 genes is downloaded from the CellAge database to extract the differentially expressed genes associated with caudal fin cell aging, totaling 29 genes. GO and KEGG enrichment analyses are performed on these 29 aging differential genes. The GO analysis shows enrichment mainly in cellular processes related to aging, such as regulation of cell division, chromatin organization, cell cycle regulation. KEGG analysis reveals that the 29 aging-related genes are primarily involved in cell cycle and cellular senescence pathways. A PPI network of aging-related genes is constructed using the STRING database and Cytoscape software. Top-ranked genes were identified by using Degree, MCC, MNC, and Closeness algorithms in the Cytohubba plugin in Cytoscape, resulting in hub genes EZH2, JUN, MYD88, RBL2, BMP4, CCND1, NFKB2, MMP9. Lastly, qRT-PCR validation of these eight hub genes further confirmed the involvement of four genes: EZH2, RBL2, BMP4, and CCND1. The hub gene screened in this study may become a potential biomarker of fish caudal fin cell senescence, which provides a valuable experimental basis for the senescence of fish caudal fin cells, especially the senescence of caudal fin cells in polyploid fish, and the reproduction and breeding improvement of polyploid fish. It also provides meaningful data for elucidating the molecular mechanism of polyploid formation in animals, as well as the formation of aging and tumour in human beings.
Antimony (Sb) is a non-essential metalloid that can be taken up by plants from contaminated soils and thus enter the food chain and threaten human health. Boehmeria nivea L. (ramie) is a promising ...phytoremediation plant for Sb-polluted soils. However, the mechanisms of antimonite (SbIII) and antimonate (SbV) uptake by ramie remain unclear. In this study, a hydroponic system was established to investigate how different substances affect the uptake of SbIII or SbV by ramie, including an energy inhibitor (malonic acid), an aquaglyceroporin inhibitor (silver nitrate), an SbV analog (phosphate—PV), and SbIII analogs (arsenite—AsIII, glycerol, silicic acid—Si, and glucose). The results indicated that ramie primarily transported Sb by increasing the Sb concentration in the bleeding sap, rather than increasing the weight of the bleeding sap. After 16 h of Sb exposure, the absolute amount of transported Sb from the roots to the aboveground parts was 1.90 times higher under SbIII than under SbV. The addition of malonic acid significantly inhibited the uptake of SbV but had limited effects on SbIII, indicating that SbV uptake was energy dependent. PV addition significantly reduced SbV uptake, while the addition of AsIII, glycerol, and Si obviously inhibited SbIII uptake. This suggested that the uptake of SbV might be via low-affinity P transporters and SbIII might use aquaglyceroporins. These findings deepen the understanding of Sb uptake pathways in ramie, contribute to a better comprehension of Sb toxicity mechanisms in ramie, and establish a foundation for identifying the most effective Sb uptake pathways, which could further improve the efficiency of phytoremediation of Sb-polluted soils.
Baling Tieshan Reservoir is one of the important artificial inland lakes in Hunan Province, with abundant aquatic resources, including high-quality fish species such as organic bighead carp. In order ...to further utilize the resource advantages of Baling Tieshan Reservoir and create a high-quality brand, this experiment analysis the biological characteristics and excellent traits of Baling Tieshan organic bighead carp (BTOBC) through techniques such as gene cloning, qRT-PCR, and paraffin section, and provides experimental basis for improving the quality of BOTBC. Pond-cultured bighead carp (PCBC) was used as a control for comparison. The findings reveal that BTOBC exhibits excellent traits in terms of body color, body shape and meat quality, which better meets the market and consumers' demands. Analysis of muscle nutrient composition and observation of muscle fiber histomorphology demonstrate a higher muscle fat proportion, and umami amino acid (AA) content, higher muscle fiber density, enhanced taste in BTOBC. Blood index and liver histology observation indicate that BTOBC has relatively healthier physiological conditions. mRNA expression detection of umami taste receptor genes T1r1 and T1r3 in various tissues shows that the meat of BTOBC has a more delicious taste. This study provides a comprehensive understanding of the nutritional characteristics of BTOBC and explores its excellent traits, which can serve as a reference for subsequent processing, comprehensive utilization, and healthy breeding in the reservoir area. Moreover, it offers a scientific basis for the rational use of reservoir resources and the sustainable development of reservoir fisheries.
Triploid crucian carp is a new breed of aquaculture with rapid growth characteristics. However, its growth regulation mechanism has not yet been elucidated. In this study, our results show that the ...expression levels of mTOR signaling pathway-related genes (AKT1, AKT2, AKT3, mTOR, 4E-BP1 and S6K1) are higher in the muscle and intestine tissues of triploid crucian carp than those of diploid red crucian carp. Embryos of triploid crucian carp exhibit a faster growth rate comparing to red crucian carp. And in muscle effect stage, the mRNA levels of mTOR signaling pathway related genes in triploid crucian carp are higher than red crucian carp, except for AKT2. Inhibition of mTOR activity with rapamycin leads to slower embryonic development and the eliminated expression of mTOR in the embryos of neurula, muscle effect, and eye pigmentation stages. Conversely, overexpression of the upstream gene AKT2 can promote the development of zebrafish embryos and affect the expression of mTOR signaling pathway. These data highlight the significant role of mTOR signaling pathway in regulating fish embryonic development and rapid growth, and might offer new insights and avenues for exploring fish embryonic development, improving fish growth.
Disinfection byproducts (DBPs) in swimming pool waters are receiving increasing attention because of their toxicity and widespread occurrence. Current studies rarely investigate the formation of DBPs ...from typical precursors in swimming pools under mixed exposure. They also rarely investigate the formation of carbonaceous DBPs (C-DBPs) and nitrogenous DBPs (N-DBPs) simultaneously. In this study, the formation of C-DBPs and N-DBPs were investigated during chlorination of mixed precursors (i.e., tryptophan, urea, creatinine, and ammonia). The effects of precursors and operation parameters were also investigated. Among the four precursors, tryptophan had the highest DBP formation potential. Urea and ammonia restrained the formation of C-DBPs but promoted the formation of more toxic N-DBPs. C-DBP yields were significantly higher than N-DBP yields under all experimental conditions. Longer reaction time and higher chlorine dosage promoted the formation of C-DBPs, while higher temperature decreased the concentration of N-DBPs. The presence of bromide not only improved the sum yields of DBPs, but also shifted chlorinated DBPs to brominated species.
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•Tryptophan had the highest DBP formation potential in swimming pools.•Creatinine significantly contributed to TCNM formation in swimming pools.•Urea and ammonia restrained C-DBP formation but promoted N-DBP formation.•Increasing reaction time and chlorine dosage promoted the formation of C-DBPs.•Higher temperature decreased the concentration of N-DBPs in swimming pools.
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