AIE fluorescent nanozyme-based dual-mode biosensor for analysis of the bioactive component hypoxanthine in meat products.

The development of facile, low-cost reliable, and precise onsite assays for the bioactive component hypoxanthine (Hx) in meat products is significant for safeguarding food safety and public health. Herein, we proposed a smartphone-assissted aggregation-induced emission (AIE) fluorogen tetraphenylethene (TPE)-incorporated amorphous Fe-doped phosphotungstates (Fe-Phos@TPE) nanozyme-based ratiometric fluorescence-colorimetric dual-mode biosensor for achieving the onsite visual detection of Hx. When the Hx existed, xanthine oxidase (XOD) catalyzed Hx into H2O2 to be further catalyzed into •OH by the prominent peroxidase activity of Fe-Phos@TPE at pH = 6.5, resulting in the oxidization of nonfluorescent o-phenylenediamine (OPD, naked-eye colorless) to be yellow fluorescent emissive 2,3-diaminophenazine (DAP, naked-eye dark yellow) at 550 nm as well as the intrinsic blue fluorescence of Fe-Phos@TPE at 440 nm to be decreased via inner-filter effect (IFE) action, thereby realizing a multi-enzyme cascade catalytic reaction at near-neutral pH to overcome the traditional acidity dependence-induced time-consuming and low sensitivity troublesome.

Advances in Metabolism and Metabolic Toxicology of Quinoxaline 1,4-Di-N-oxides.

Quinoxaline 1,4-di-N-Oxides (QdNOs) have been used as synthetic antimicrobial agents in animal husbandry and aquaculture. The metabolism and potential toxicity have been also concerns in recently years. The metabolism investigations showed that there were 8 metabolites of Carbadox (CBX), 34 metabolites of Cyadox (CYA), 33 metabolites of Mequindox (MEQ), 35 metabolites of Olaquindox (OLA), and 56 metabolites of Quinocetone (QCT) in different animals. Among them, Cb3 and Cb8, M6, and O9 are metabolic residual markers of CBX, MEQ and OLA, which are associated with N → O reduction. Toxicity studies revealed that QdNOs exhibited severe tumorigenicity, cytotoxicity, and adrenal toxicity. Metabolic toxicology showed that toxicity of QdNOs metabolites might be related to the N → O group reduction, and some metabolites exhibited higher toxic effects than the precursor, which could provide guidance for further research on the metabolic toxicology of QdNOs and provide a wealth of information for food safety evaluation.

Pyrococcus furiosus argonaute based Alicyclobacillus acidoterrestrsis detection in fruit juice.

Alicyclobacillus acidoterrestris is the major threat to fruit juice for its off-odor producing characteristic. In this study, Pyrococcus furiosus Argonaute (PfAgo), a novel endonuclease with precise DNA cleavage activity, was used for A. acidoterrestrisdetection, termed as PAD. The partially amplified 16 S rRNA gene of A. acidoterrestris can be cleaved by PfAgo activated by a short 5'-phosphorylated single strand DNA, producing a new guide DNA (gDNA). Then, PfAgo was activated by the new gDNA to cut a molecular beacon (MB) with fluorophore-quencher reporter, resulting in the recovery of fluorescence. The fluorescent intensity is positively related with the concentration of A. acidoterrestris. The PAD assay showed excellent specificity and sensitivity as low as 101 CFU/mL, which can be a powerful tool for on-site detection of A. acidoterrestris in fruit juice industry in the future, reducing the economic loss.

Differential Disruption of Glucose and Lipid Metabolism Induced by Phthalates in Human Hepatocytes and White Adipocytes.

Phthalic acid esters (PAEs), commonly used as plasticizers, are pervasive in the environment, leading to widespread human exposure. The association between phthalate exposure and metabolic disorders has been increasingly recognized, yet the precise biological mechanisms are not well-defined. In this study, we explored the effects of monoethylhexyl phthalate (MEHP) and monocyclohexyl phthalate (MCHP) on glucose and lipid metabolism in human hepatocytes and adipocytes. In hepatocytes, MEHP and MCHP were observed to enhance lipid uptake and accumulation in a dose-responsive manner, along with upregulating genes involved in lipid biosynthesis. Transcriptomic analysis indicated a broader impact of MEHP on hepatic gene expression relative to MCHP, but MCHP particularly promoted the expression of the gluconeogenesis key enzymes G6PC and FBP1. In adipocytes, MEHP and MCHP both increased lipid droplet formation, mimicking the effects of the Peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone (Rosi). Transcriptomic analysis revealed that MEHP predominantly altered fatty acid metabolism pathways in mature adipocytes (MA), whereas MCHP exhibited less impact. Metabolic perturbations from MEHP and MCHP demonstrate shared activation of the PPARs pathway in hepatocytes and adipocytes, but the cell-type discrepancy might be attributed to the differential expression of PPARγ. Our results indicate that MEHP and MCHP disrupt glucose and lipid homeostasis in human liver and adipose through mechanisms that involve the PPAR and adenosine monophosphate-activated protein kinase (AMPK) signaling pathways, highlighting the nuanced cellular responses to these environmental contaminants.

Antibiotic resistance genes profile in the surface sediments of typical aquaculture areas across 15 major lakes in China.

Aquatic farming is considered as a major source of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) for the natural environment of the lakes. ARB and ARGs in the natural environment have increased quickly because of the human activities. Here, we have profiled the diversity and abundance of ARGs in sediments from the typical aquaculture areas around 15 major lakes in China using PCR and qPCR, and further assessed the risk factor shaping the occurrence and distribution of ARGs. And class 1, 2 and 3 integrons were initially detected by PCR with specific primers. ARGs were widely distributed in the lakes: Weishan Lake and Poyang Lake showed high diversity of ARGs, followed by Dongting Lake, Chao Lake and Tai Lake. Generally, the ARGs in the Middle-Lower Yangtze Plain were more abundant than those in the Qinghai-Tibet Plateau. Tetracycline resistance genes (tet(C), tet(A) & tet(M)) were prominent in sediments, and the next was AmpC ß-lactamase gene group BIL/LAT/CMY, and the last was the genes resistance to aminoglycoside (strA-strB). Partial least squares path modeling analysis (PLS-PMA) revealed that livestock had a significant direct effect on the distribution of ARGs in lakes, and population might indirectly influence the profiles of ARGs by affecting the scale of livestock and aquaculture. The detectable rate of class 1, 2 and 3 integrons were 80%, 100% and 46.67%, respectively. The prevalence of integrons might play a key role in promoting more frequent horizontal gene transfer (HGT) events, resulting in the environmental mobilization and dissemination of ARGs between bacteria.

Recent advances in nanopore-based analysis for carbohydrates and glycoconjugates.

Saccharides are not only the basic constituents and nutrients of living organisms, but also participate in various life activities, and play important roles in cell recognition, immune regulation, development, cancer, etc. The analysis of carbohydrates and glycoconjugates is a necessary means to study their transformations and physiological roles in living organisms. Existing detection techniques can hardly meet the requirements for the analysis of carbohydrates and glycoconjugates in complex matrices as they are expensive, involve complex derivatization, and are time-consuming. Nanopore sensing technology, which is amplification-free and label-free, and is a high-throughput process, provides a new solution for the identification and sequencing of carbohydrates and glycoconjugates. This review highlights recent advances in novel nanopore-based single-molecule sensing technologies for the detection of carbohydrates and glycoconjugates and discusses the advantages and challenges of nanopore sensing technologies. Finally, current issues and future perspectives are discussed with the aim of improving the performance of nanopores in complex media diagnostic applications, as well as providing a new direction for the quantification of glycan chains and the study of glycan chain properties and functions.

Recent advances of nanopore technique in single cell analysis.

Single cells and their dynamic behavior are closely related to biological research. Monitoring their dynamic behavior is of great significance for disease prevention. How to achieve rapid and non-destructive monitoring of single cells is a major issue that needs to be solved urgently. As an emerging technology, nanopores have been proven to enable non-destructive and label-free detection of single cells. The structural properties of nanopores enable a high degree of sensitivity and accuracy during analysis. In this article, we summarize and classify the different types of solid-state nanopores that can be used for single-cell detection and illustrate their specific applications depending on the size of the analyte. In addition, their research progress in material transport and microenvironment monitoring is also highlighted. Finally, a brief summary of existing research challenges and future trends in nanopore single-cell analysis is tentatively provided.

Facile synthesis of hydroxylated triazine-based magnetic microporous organic network for ultrahigh adsorption of phenylurea herbicides: An experimental and density-functional theory study.

Microporous organic networks (MONs) are highly porous materials that are particularly useful in analytical chemistry. However, the use of these materials is often limited by the functional groups available on their surface. Here, we described the polymerization of a sea urchin-like structure material at ambient temperature, that was functionalized with hydroxyl, carboxyl, and triazine groups and denoted as OH-COOH-MON-TEPT. A substantial proportion of OH-COOH-MON-TEPT was intricately decorated EDA-Fe3O4, creating a well-designed configuration (EDA-Fe3O4 @OH-COOH-MON-TEPT-EDC) for superior adsorption of the target analytes phenylurea herbicides (PUHs) via magnetic solid-phase extraction (MSPE). The proposed method showed remarkably low limits of detection ranging from 0.03 to 0.22 ng·L-1. Experimental investigations and theoretical analyses unveiled the adsorption mode between EDA-Fe3O4 @OH-COOH-MON-TEPT-EDC and PUHs. These findings establish a robust foundation for potential applications of EDA-Fe3O4 @OH-COOH-MON-TEPT-EDC in the analysis of various polar contaminants.

Enzyme-Assisted Endogenous Guide DNA Generation-Mediated Pyrococcus furiosus Argonaute for Alicyclobacillus acidoterrestris Detection.

Pyrococcus furiosusArgonaute (PfAgo) emerged as a novel endonuclease for the nucleic acid test recently. However, the input of exogenous guide DNA (gDNA) to activate PfAgo has reduced its flexibility. In this work, an enzyme-assisted endogenous gDNA generation-mediated PfAgo for the target detection strategy, termed EGG-PAD, was proposed. With the aid of EcoR Ι, the target double-strand DNA was cut, producing a phosphate group at the 5' end, functioning as gDNA to activate PfAgo for nucleic acid detection. The applicability of this assay was tested in the detection ofAlicyclobacillus acidoterrestris, a bacterium causing the spoilage of fruit juice, showing excellent sensitivity and specificity, ascribed to the "duplex amplification and triple insurance" mechanism. Moreover, EGG-PAD exhibited superior versatility in the identification of common foodborne pathogens. This powerful platform could also be an on-site test tool for detecting nucleic acid-containing organisms such as tumor cell, pathogen, and virus in the future.

Exposure and Health Risk Assessment of Heavy Metal in Crayfish from the Middle and Lower Reaches of the Yangtze River.

Red swamp crayfish (Procambarus clarkia) is an exposed species to heavy metals due to their lifestyle of direct contact with sediments. Based on the complete crayfish industry, we focus on the presence of heavy metals in crayfish from different circulation links, which provides a new idea for the investigation of heavy metals in food. To analyze the exposure levels of heavy metals in crayfish during aquaculture and circulation, the five elements (Cd, Pb, Hg, Cr, Cu) in crayfish from 126 sampling sites were investigated. Cultured environmental samples were collected for Spearman correlation analysis. Monte Carlo simulation was used to analyze the uncertain health risks of heavy metals in crayfish. The results indicated that the average heavy metal concentrations in crayfish were all below the limit threshold values. The hepatopancreas was the main target organ for heavy metal accumulation (Cd: 0.3132 mg/kg; Pb: 0.0258 mg/kg; Hg: 0.0072 mg/kg; Cr: 0.1720 mg/kg; Cu: 10.6816 mg/kg). The positive correlation of heavy metal content between crayfish and sediments was not significant under the crayfish-rice coculture model. The 95th HI values for adults and children ranged from 0.022 to 0.042 and 0.071 to 0.137, well below 1, indicating that heavy metals do not pose a noncarcinogenic risk to humans. The potential carcinogenic risk of Cd and Cr in crayfish should be taken seriously, as the 95th CR values for children have reached 4.299 × 10-5 and 6.509 × 10-5, respectively.

A simple fluorescence pyrocatechol-polyethyleneimine detection method for 3-MCPD.

A rapid fluorescence detection method was established for 3-monochloropropane-1,2-diol (3-MCPD). The detection system works based on the fluorescence quenching of pyrocatechol-polyethyleneimine (PCh-PEI) polymer by 3-MCPD. The fluorescence quenching ability of 3-MCPD for PCh-PEI polymer was measured at different pH and temperatures. Indeed, in the presence of 3-MCPD, the fluorescence intensity of PCh-PEI polymer solution was quenched best at 100 °C and pH 8.5. Also, the effect of different concentrations of 3-MCPD on the optical properties of the PCh-PEI polymer was examined. Under optimal experimental conditions, fluorescence detection was linear in a range of 0.08-2.0 mg per L 3-MCPD, with a calculated detection limit of 0.06 mg L-1 and a correlation coefficient of 0.9974. Concisely, the reported method has good sensitivity and can be used for the rapid detection of 3-MCPD contamination in food products.

Target Analysis of Polychlorinated Naphthalenes and Nontarget Screening of Organic Chemicals in Bovine Milk, Infant Formula, and Adult Milk Powder by High-Resolution Mass Spectrometry.

Infant formula is intended as an effective substitute for breast milk but is the main source of polychlorinated naphthalenes (PCNs) to nonbreastfed infants. We performed target and nontarget analyses to determine PCNs and identify other organic contaminants in infant formula. The mean PCN concentrations in infant formula, milk powder, and bovine milk were 106.1, 88.8, and 78.2 µg kg-1 of dry weight, respectively. The PCN congener profiles indicated that thermal processes and raw materials were probably the main sources of PCNs in infant formula. A health risk assessment indicated that PCNs in infant formula do not pose health risks to infants. Using gas chromatography-Orbitrap mass spectrometry, 352, 372, and 161 organic chemicals were identified in the infant formula, milk powder, and bovine milk samples, respectively. Phthalate esters were detected in all four plastic-packed milk powder samples. The results indicated milk becomes more contaminated with organic chemicals during manufacturing, processing, and packaging.

Advancing food safety risk assessment in China: development of new approach methodologies (NAMs).

Novel techniques and methodologies are being developed to advance food safety risk assessment into the next-generation. Considering the shortcomings of traditional animal testing, new approach methodologies (NAMs) will be the main tools for the next-generation risk assessment (NGRA), using non-animal methodologies such as in vitro and in silico approaches. The United States Environmental Protection Agency and the European Food Safety Authority have established work plans to encourage the development and application of NAMs in NGRA. Currently, NAMs are more commonly used in research than in regulatory risk assessment. China is also developing NAMs for NGRA but without a comprehensive review of the current work. This review summarizes major NAM-related research articles from China and highlights the China National Center for Food Safety Risk Assessment (CFSA) as the primary institution leading the implementation of NAMs in NGRA in China. The projects of CFSA on NAMs such as the Food Toxicology Program and the strategies for implementing NAMs in NGRA are outlined. Key issues and recommendations, such as discipline development and team building, are also presented to promote NAMs development in China and worldwide.

[Associations of a mixture of eleven endocrine disruptors in human urine with the risk of papillary thyroid cancer].

OBJECTIVE: To examine the associations of human exposure to a mixture of 11 endocrine disruptors(EDCs) with the risk of papillary thyroid cancer(PTC), and to identify the priority of these EDCs. METHODS: EDCs were determined in fasting urine specimens to represent human exposure. Logistics regressions were performed to examine the associations between individual EDC and PTC risk. Bayes kernel machine regression was applied to examine the associations between the mixture of EDCs and PTC risk. Weighted quantile sum(WQS) regression and LASSO regression were performed to identify the main contributor. RESULTS: In the multivariate logistic regression model, after adjusting for a series of variables, 11 endocrine disruptors were statistically significantly correlated with the risk of PTC(P<0.05). In BKMR models, the mixture of EDCs was positively correlated with the risk of PTC(P<0.05). The weight and coefficient of mono(2-ethyl-5-hydroxyhexyl) phthalate(MEHHP) was 0.62 and 1.58 in WQS and LASSO models, respectively, which were much higher than those of the other EDCs. CONCLUSION: Combined exposure to o a variety of EDCs might promote the risk of PTC, and MEHHP was identified as the main contributor.

Dual-Modal Bimetallic Nanozyme-Based Sensing Platform Combining Colorimetric and Photothermal Signal Cascade Catalytic Enhancement for Detection of Hypoxanthine to Judge Meat Freshness.

Considering the enormous demand for meat in people's daily lives, the development of efficient meat freshness assays is of great significance for safeguarding food safety. Here, a novel bimetallic nanozyme Fe@CeO2 with high peroxidase-like activity was first synthesized by embedding ferrocenecarboxylic acid (Fc) into hollow CeO2 nanospheres, which combined with xanthine oxidase (XOD) to develop a self-supplying H2O2-facilitated enzymatic cascade catalytic system of XOD + Fe@CeO2, yielding a meat freshness indicator hypoxanthine (Hx)-responsive colorimetric and photothermal dual-mode analytical platform for judging meat freshness upon the assistance of 3,3',5,5'-tetramethylbenzidine (TMB). Owing to the catalytic activity of XOD to convert Hx into H2O2, Fe@CeO2 rapidly dissociated it into •OH via a peroxidase activity-triggered Fenton-like reaction, emerging a typical enzymatic cascade catalytic reaction. As a result, the colorless TMB was oxidized to be the product of dark-blue oxTMB by •OH, with a chromogenic reaction-driven absorption enhancement at 652 nm, which endowed it with a significant photothermal effect under 660 nm laser irradiation. On this basis, an Hx concentration-dependent colorimetric and photothermal dual-mode signal cascade catalytic enhancement sensing platform was proposed by integrating with a Color Picker App-installed smartphone and a 660 nm laser-equipped handheld thermal imager, achieving the onsite quantitative, reliable, and visual detection of Hx in real meat samples for judging meat freshness with acceptable results. Notably, the colorimetric and photothermal dual-mode signal cascade catalytic enhancement improved not only the reliability but also the sensitivity of the assay, which provided new insights for efficient onsite visual monitoring of meat freshness to safeguard food safety.

Insight into the negative effect and lipid profile alterations in liver of mice exposed to methylimidazolium ionic liquids, a novel "green" solvent.

Background: Ionic liquids (ILs) have been recognized as potential environmentally friendly solvents; however, their potential toxicity to living organisms warrants thorough investigation, particularly for novel-generation ILs in mammalian models. Methods: In this study, we examined the hepatic effects and disruption of lipid metabolism in mice exposed to 1-heptyl-3-methylimidazolium chloride (C7[MIM]Cl), a novel ILs. After four weeks of oral administration at different dosages (2.38, 5.95, and 11.9 mg/kg b.w.), we conducted clinical chemistry analysis and histopathological examination of the liver to assess biochemical and structural changes. Results: The low-dose C7[MIM]Cl group exhibited a significant increase in alanine aminotransferase (ALT) levels, while aspartate aminotransferase (AST) levels were elevated in both low-dose and high-dose groups without statistical significance. Histopathological examination showed inflammatory cell infiltration and red blood cell aggregation in the livers of mice exposed to C7[MIM]Cl, particularly in the high-dose group. Oxidative stress levels showed moderate changes in response to C7[MIM]Cl exposure. Notably, hepatic biochemical parameters revealed a dose-dependent increase in triglycerides (TG) levels with statistically significant differences compared to the control group (P ≤ 0.01). Targeted lipidomic analysis revealed notable alterations in liver lipids of mice exposed to C7[MIM]Cl, with lysophosphatidylethanolamine (18:0), phosphatidylcholines (18:0), and phosphatidylcholines (19:0) identified as critical lipids associated with C7[MIM]Cl exposure. Furthermore, metabolic pathway analyses demonstrated significant disturbances in the glycerophospholipid metabolic pathway. Conclusion: These findings provide valuable insights into the hepatic effects of C7[MIM]Cl exposure and novel perspectives on the disruption of lipid metabolism underlying ILs toxicity.

The Mechanism of Mori Folium and Eucommiae Cortex against Cyclophosphamide-Induced Immunosuppression Integrating Network Pharmacology, Molecular Docking, Molecular Dynamics Simulations, and Experimental Validation.

It has been reported that Mori Folium (MF) and Eucommiae Cortex (EC) exhibit pharmacological effects in the treatment of immunosuppression. However, the mechanism of MF and EC against immunosuppression remains unclear. This study aims to explore the mechanism of action of MF and EC for the treatment of immunosuppression through network pharmacology, molecular docking, molecular dynamics simulations and animal experiments. As a result, 11 critical components, 9 hub targets, and related signaling pathways in the treatment of immunosuppression were obtained based on network pharmacology. The molecular docking suggested that 11 critical components exhibited great binding affinity to 9 hub targets of immunosuppression. The molecular dynamics simulations results showed that (-)-tabernemontanine-AR, beta-sitosterol-AR and Dehydrodieugenol-HSP90AA1 complexes are stably bound. Additionally, in the animal experiments, the treated group results compared to the control group suggest that MF and EC have a significant effect on the treatment of immunosuppression. Therefore, MF and EC treatment for immunosuppression may take effects in a multi-component, multi-target, and multi-pathway manner. The results herein may provide novel insights into the treatment of immunosuppression in humans.

ß-Carbolines norharman and harman change neurobehavior causing neurological damage in Caenorhabditis elegans.

ß-Carbolines norharman and harman, belonging to the class of heterocyclic aromatic amines (HAAs), are typical hazardous substances produced during the thermal processing of food. Compared to other HAAs, there have been limited reports on the toxicity of ß-carbolines. Nevertheless, the current studies are concerned with the neurotoxic effects of norharman and harman at high doses. It is still unknown whether the relatively low dose of ß-carbolines in foods induces neurotoxicity and the mechanism of the toxicity. In this study, C. elegans was exposed to a series of gradients of norharman and harman (0, 0.05, 5, and 10 mg L-1). The survival rate and indicators of ethology (locomotor behaviors, foraging behavior, and chemotaxis ability) were assessed. The antioxidant system and the contents of neurotransmitters, as well as the activity of acetylcholinesterase (AChE), were evaluated. Additionally, the RNA-seq screening of differentially expressed genes (DEGs) revealed the potential molecular mechanisms of norharman- and harman-induced toxic effects. Our results indicated that the risk of long-term exposure to norharman and harman at low doses (food-related doses) should be emphasized. Moreover, ß-carbolines might induce neurotoxicity by causing oxidative damage, regulating the content of neurotransmitters, and interfering with cytochrome P450 metabolism. This study would provide a toxicological basis for the neurotoxicity of ß-carbolines and lay the foundation for the risk assessment of endogenous pollutants in food.

Unveiling the molecular interactions between alkyl imidazolium ionic liquids and human serum albumin: Implications for toxicological significance.

Alkyl imidazolium-based ionic liquids (ILs) are promising for diverse industrial applications; however, their growing prevalence has raised concerns regarding human exposure and potential health implications. A critical aspect to be clarified to address the adverse health effects associated with ILs exposure is their binding mode to human serum albumin (HSA). In this study, we delved into the binding interactions between three alkyl imidazolium ILs (1-hexyl-3-methyl-imidazolium (C6[MIM]), 1-ethyl-3-methyl-imidazolium chloride (C8[MIM]) and 1-decyl-3-methyl-imidazolium (C10[MIM]) and human serum albumins (HSAs) using a comprehensive approach encompassing molecular docking and multi-spectroscopy (UV-visible, Fluorescence, Circular Dichroism, FTIR). Furthermore, for the first time, we developed an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach time to quantify plasma protein binding rates. Our results revealed that the ILs primarily bind to the hydrophobic cavity of HSA through hydrogen bonding and van der Waals forces, forming stable complexes via static quenching. This affected HSA's secondary structure, reducing α-helical content, particularly around specific residues. Equilibrium dialysis and ultrafiltration coupled with UPLC-MS/MS analysis showed modest plasma protein binding rates (17.84%-31.85%) for the three ILs, with no significant influence from alkyl chain effects or concentration relationship. Lower plasma protein binding rates can affect bioavailability and distribution of ILs, potentially influencing their toxicity. These findings provide critical insights into the potential toxicological implications at the molecular level, thereby contributing to continuous efforts to evaluate the risk profiles and ensure the safe utilization of these compounds.