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This study established a residue detection method based on the QuEChERS pre-treatment method and combined it with high-performance liquid chromatography-tandem mass spectrometry to test six herbicides (metamitron, clopyralid, desmedipham, phenmedipham, ethofumesate, and haloxyfop-p-methyl) in sugar beet plants, soil, and roots. The degradation dynamics and terminal residues of each herbicide in sugar beets were analysed. Finally, the dietary risks of various herbicides in sugar beets were evaluated based on the dietary structure of Chinese people, and the risk quotient values were below 100%. Using this detection method, all reagents exhibited good linearity (0.9724 ≤ R2 ≤ 0.9998), The limit of quantification (LOQ) ranged from 0.01 to 0.05â¯mg/L, the matrix effect ranged from -1.2% to -50%, the addition recovery rate ranged from 77.00% to 103.48%, and the relative standard deviation ranged from 1.61% to 16.17%; therefore, all indicators of this method met the residue detection standards. Under field conditions, the half-lives (t1/2) ranged about 0.65 â¼ 2.96 d and 0.38 â¼ 27.59 d in sugar beet plants and soil, respectively. All herbicides were easily degraded in sugar beet plants and soil (t1/2 < 30 d). The terminal residue amounts in the beet plants, soil, and roots ranged from < LOQ to 0.243â¯mg/kg. The dietary risk assessment of each pesticide was conducted based on the residual median of the terminal residues and the highest residual values on the edible part of the beetroot. The chronic exposure risk quotient (RQc) and acute exposure risk quotient (RQa) values were < 100%, indicating that the residue of each pesticide in beetroot posed low risks to consumers in China at the recommended dosage.
Assuntos
Beta vulgaris , Compostos de Flúor , Herbicidas , Resíduos de Praguicidas , Praguicidas , Piridinas , China , Herbicidas/análise , Resíduos de Praguicidas/análise , Praguicidas/análise , Solo/química , Açúcares , VerdurasRESUMO
Fe-based amorphous coatings are ideal materials for surface protection due to their outstanding mechanical properties and corrosion resistance. However, coating defects are inevitably formed during the preparation of coatings by thermal spray technology, which seriously affects the corrosion performance. Inspired by bionics, conceiving superhydrophobic surfaces with liquid barrier properties has become a new idea for the corrosion protection of metal surfaces. In this work, based on surface hydroxylation, we designed a superhydrophobic Fe-based amorphous coating with corrosion resistance by chemical etching combined with a thermally driven preparation strategy. The obtained superhydrophobic coatings exhibit liquid repellency (contact angle >150°) and excellent corrosion resistance (corrosion current density and passive current density reduced by 3 orders of magnitude). The results revealed that the superhydrophobic behavior stems from the construction of hydroxyl-induced surface micro-/nanomultilevel aggregates (cluster structures). The hydrophobic agent layer deposited on the surface of cluster aggregates and the nanoparticle elements that constitute the clusters dominate the corrosion resistance of the coating. This work provides an effective guide to the design of high-corrosion-resistant Fe-based amorphous alloy coatings and promotes their engineering applications.
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Propaquizafop is a highly efficient aryloxy phenoxy propionate chiral herbicide. However, the use of propaquizafop, including its safe use methods, residue patterns, dietary risk assessment, and maximum residue limits, for ginseng, a traditional Chinese medicinal plant, has not been studied. An analytical method was established for the simultaneous determination of propaquizafop and its four metabolites in ginseng soil, fresh ginseng, ginseng plant, and dried ginseng using HPLC-MS/MS. This approach showed good linearity (R2 ranging from 0.9827 to 0.9999) and limit of quantification ranging from 0.01 to 0.05 mg/kg. The intra- and interday recovery rates of this method ranged from 71.6 to 107.1% with relative standard deviation ranging from 1.3 to 23.2%. The method was applied to detect residual samples in the field, and it was found that the degradation of propaquizafop in ginseng plants and soil followed a first-order kinetic equation. R2 was between 0.8913 and 0.9666, and the half-life (t1/2) ranged from 5.04 to 8.05 days, indicating that it was an easily degradable pesticide (T1/2 < 30 days). The final propaquizafop residues in ginseng soil, plants, fresh ginseng, and dried ginseng ranged from 0.017 to 0.691 mg/kg. A dietary risk assessment was conducted on the final propaquizafop residue in fresh and dried ginseng. The results showed that the chronic exposure risk quotient values were less than 100% for fresh and dried ginseng (1.15% for fresh ginseng and 1.13% for dried ginseng). This illustrates that the dietary risk associated with the use of 10% propaquizafop emulsifiable concentrate in ginseng is very low. Thus, applying 750 mL/ha of propaquizafop on ginseng could not pose an unacceptable risk to public health. The results of the present study support the registration of propaquizafop in ginseng.
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Panax , Resíduos de Praguicidas , Poluentes do Solo , Espectrometria de Massas em Tandem/métodos , Panax/química , Resíduos de Praguicidas/análise , Poluentes do Solo/química , Medição de Risco , Meia-Vida , Solo/química , ChinaRESUMO
Bacterial infection is a critical factor in wound healing. Due to the abuse of antibiotics, some pathogenic bacteria have developed resistance. Thus, there is an urgent need to develop a non-antibiotic-dependent multifunctional wound dressing for the treatment of bacteria-infected wounds. In this work, a multifunctional AOCuT hydrogel embedded with CuS@TA-Fe nanoparticles (NPs) through Schiff base reaction between gelatin quaternary ammonium salt - gallic acid (O-Gel-Ga) and sodium dialdehyde alginate (ADA) along with electrostatic interactions with CuS@TA-Fe NPs is prepared. These composite hydrogels possess favorable injectability, rapid shape adaptation, electrical conductivity, photothermal antimicrobial activity, and biocompatibility. Additionally, the doped NPs not only impart fast self-healing properties and excellent adhesion performance to the hydrogels, but also provide excellent peroxide-like properties, enabling them to scavenge free radicals and exhibit anti-inflammatory and antioxidant capabilities via photothermal (PTT) and photodynamic (PDT) effects. In an S. aureus infected wound model, the composite hydrogel effectively reduces the expression level of wound inflammatory factors and accelerates collagen deposition, epithelial tissue, and vascular regeneration, thereby promoting wound healing. This safe and synergistic therapeutic system holds great promise for clinical applications in the treatment of infectious wounds.
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Anti-Infecciosos , Nanopartículas , Peróxidos , Hidrogéis/farmacologia , Staphylococcus aureus , Antibacterianos/farmacologia , AlginatosRESUMO
OBJECTIVE: We aimed to explore the expression and clinical prognostic significance of PAQR4 in hepatocellular carcinoma (HCC). METHODS: We obtained the gene expression matrix and clinical data of HCC from the cancer genome atlas (TCGA) and international cancer genome consortium (ICGC) databases. The prognostic value of PAQR4 in HCC was evaluated using the Kaplan-Meier and Cox regression analyses. PAQR4-related pathways were explored by gene set enrichment analysis (GSEA). A clinical nomogram prognostic model based on the PAQR family was constructed using Cox proportional hazards models. RESULTS: We found that PAQR4 is overexpressed in HCC from multiple databases; additionally, quantitative real-time polymerase chain reaction (qRT-PCR) validated the upregulation of PAQR4 in HCC. PAQR4 expression was related to age, grade, alpha fetoprotein (AFP), T classification and clinical stage of HCC patients. High PAQR4 expression was associated with poor overall survival and was an independent prognostic factor for HCC patients through Kaplan-Meier analysis and Cox regression analysis, respectively. In addition, GSEA identified that the high PAQR4 expression phenotype was involved in the cell cycle, Notch signaling pathway, mTOR signaling pathway, etc. Finally, three PAQR family genes (PAQR4, PAQR8 and PAQR9) were associated with the prognosis of patients with HCC. A clinical nomogram prediction model was verified in TCGA training and ICGC validation sets, and it exerted dramatic predictive efficiency in this study. CONCLUSIONS: PAQR4 may be regarded as a promising prognostic biomarker and therapeutic target for HCC.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Proteínas de Membrana/genética , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Nomogramas , PrognósticoRESUMO
With the aggressive scaling of integrated circuits, ruthenium has been proposed as the next generation barrier material to replace the conventional bilayer of tantalum and tantalum nitride due to its properties such as allowing direct copper electrodeposition. In this work, the effect of ethylenediamine (EDA) on the chemical mechanical polishing (CMP) properties of ruthenium in H2O2-based slurries was investigated. The results show that EDA or H2O2 alone has little effect, but the combined use of EDA and H2O2 significantly enhances the removal rate of ruthenium. Subsequently, the mechanism of action of ruthenium removal promoted by EDA was studied by combining CMP experiments, electrochemical experiments and surface chemical characterization methods. It is indicated that EDA molecules react with ruthenium oxide (not ruthenium metal) to generate a large number of complexes, which promotes the dissolution of ruthenium oxides and the corrosion of ruthenium. More importantly, the oxide layers on the ruthenium surface become rough and porous, and can be easily removed by mechanical action during the ruthenium CMP process. Meanwhile, the use of EDA can reduce the electrostatic repulsive force between the SiO2 particles and ruthenium surface in the CMP process, thus further accelerating the ruthenium removal. In order to obtain an adequate removal rate selectivity of ruthenium versus copper, the corrosion inhibitors for copper were added. As a consequence, the removal rate selectivity of 1.13 : 1 was obtained, while also reducing the corrosion potential difference between ruthenium and copper to 17 mV.
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The cleaning potential of selected Chinese bituminous coals during coal preparation was evaluated in terms of coal quality, cleaning grade, and cleanability. The cleaning potentials were determined for coals sampled from a total of six seams, two each in three different general exploration areas in southern Shanxi, China. Distribution maps of resources with different cleaning potential characteristics were prepared using mapping and geographical information software. In each case, the area and calculated reserves for coals having different classifications of cleaning potentials were determined. The total areal extent of the six coals studied is about 410 million m2, and the total reserves of these coals amount to about 1460 million tonnes, which include coals of poor, fair, good, and proficient cleanabilities. The proportion of high-quality coals is about 28.9%. Coals that can be processed into high-quality coals account for about 69.2%. A cleaning potential gradient is proposed for indicating the cleaning potential level, and an equation for calculating it is established. The necessity of processing raw coal of good quality is also to be considered in terms of economics. It does not make economic sense to process coal with an organic sulfur content more than 1.5%, even though it may have a good cleanability.