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Climate change is a new disrupter to global fisheries systems and their governance frameworks. It poses a pressing management challenge, particularly in China, which is renowned as the world's largest fishing country and seafood producer. As climate change continues to intensify in the region and climate awareness grows within the country's national policy, the need to understand China's fisheries' resilience to the escalating climate crisis becomes paramount. In this study, we conduct an interdisciplinary analysis to assess the vulnerability and risk of China's marine capture fisheries in response to climate change. This study employs a spatially explicit, indicator-based approach with a coupled social-ecological framework, focusing on 67 species and 11 coastal regions. By integrating diverse sets of climatic, ecological, economic, societal, and governance indicators and information, we elucidate the factors that could hinder climate adaptation, including a limited understanding of fish early life stages, uncertainty in seafood production, unequal allocation and accessibility of resources, and inadequate consideration of inclusive governance and adaptive management. Our results show that species, which have managed to survive the stress of overfishing, demonstrate a remarkable ability to adapt to climate change. However, collapsing stocks such as large yellow croaker face a high risk due to the synergistic effects of inherent biological traits and external management interventions. We emphasize the imperative to build institutional, scientific, and social capacity to support fisheries adaptation. The scientific insights provided by this study can inform fisheries management decisions and promote the operationalization of climate-resilient fisheries in China and other regions.
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Conservação dos Recursos Naturais , Pesqueiros , Animais , Mudança Climática , Meio Social , China , Ecossistema , PeixesRESUMO
Efficient and accurate acquisition of cellular biomolecular information is crucial for exploring cell fate, achieving early diagnosis, and the effective treatment of various diseases. However, current DNA biosensors are mostly limited to single-target detection, with few complex logic circuits for comprehensive analysis of three or more targets. Herein, we designed a sea anemone-like DNA nanomachine based on DNA strand displacement composed of three logic gates (YES-AND-YES) and delivered into the cells using gold nano bipyramid carriers. The AND gate activation depends on the trigger chain released by upstream DNA strand displacement reactions, while the output signal relies on the downstream DNAzyme structure. Under the influence of diverse inputs (including enzymes, miRNA, and metal ions), the interconnected logic gates simultaneously perform logical analysis on multiple targets, generating a unique output signal in the YES/NO format. This sensor can successfully distinguish healthy cells from tumor cells and can be further used for the diagnosis of different tumor cells, providing a promising platform for accurate cell-type identification.
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DNA Catalítico , Anêmonas-do-Mar , Animais , Anêmonas-do-Mar/genética , DNA/química , DNA Catalítico/química , Lógica , Ouro , Computadores MolecularesRESUMO
Cuproptosis, a recently discovered copper-dependent cell death, presents significant potential for the development of copper-based nanoparticles to induce cuproptosis in cancer therapy. Herein, a unique ternary heterojunction, denoted as HACT, composed of core-shell Au@Cu2O nanocubes with surface-deposited Titanium Dioxide quantum dots and modified with hyaluronic acid is introduced. Compared to core-shell AC NCs, the TiO2/Au@Cu2O exhibits improved energy structure optimization, successfully separating electron-hole pairs for redox use. This optimization results in a more rapid generation of singlet oxygen and hydroxyl radicals triggering oxidative stress under ultrasound radiation. Furthermore, the HACT NCs initiate cuproptosis by Fenton-like reaction and acidic environment, leading to the sequential release of cupric and cuprous ions. This accumulation of copper induces the aggregation of lipoylated proteins and reduces iron-sulfur proteins, ultimately initiating cuproptosis. More importantly, HACT NCs show a tendency to selectively target cancer cells, thereby granting them a degree of biosecurity. This report introduces a ternary heterojunction capable of triggering both cuproptosis and oxidative stress-related combination therapy in a stimulus-responsive manner. It can energize efforts to develop effective melanoma treatment strategies using Cu-based nanoparticles through rational design.
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Nanozymes, serving as synthetic alternatives to natural enzymes, offer several benefits including cost-effectiveness, enzyme-like catalytic abilities, enhanced stability, adjustable catalytic activity, easy recyclability, mild reaction conditions, and environmental friendliness. Nonetheless, the ongoing quest to develop nanozymes with enhanced activity and to delve into the catalytic mechanism remains a challenge. In our research, we effectively developed Au@CuO nanocomposites (Au@CuO Nc), replicating the functions of four enzymes found in nature: peroxidase (POD), catalase (CAT), glutathione peroxidase (GPx), and oxidase (OXD). The catalytic efficiency of Au@CuO Nc for TMB oxidation (oxTMB) was approximately 4.8 times greater than that of plain Cu2O cubes, attributed to the synergistic catalytic impact between the Au element and Cu2O within Au@CuO Nc. Mechanistic studies revealed that the novel Au@CuO Nc nanozyme greatly enhances the decomposition of H2O2 to reactive oxygen species (ROS) intermediates (ËOH, ËO2- and 1O2), resulting in increased POD-like activity of the single-component Cu2O cubes. When an antioxidant like TA was added to the chromogenic system, it converted oxTMB into a colorless form of TMB, enabling further evaluation of TA. Hence, a colorimetric sensor was developed for the rapid and precise quantitative measurement of TA, demonstrating strong linearity between 0.3 and 2.4 µM and featuring a low detection threshold of 0.25 µM. Moreover, this sensor was effectively utilized for the assessment of TA in actual tea samples. This work innovatively proposes a simplified and reliable strategy for the advanced design of highly effective Cu-based nanozymes, enhancing enzyme-like reactions for simultaneous, on-site colorimetric probing of antioxidants.
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Zinc oxide nanoparticles (ZnO NPs) stand as among the most significant metal oxide nanoparticles in trigger the formation of reactive oxygen species (ROS) and induce apoptosis. Nevertheless, the utilization of ZnO NPs has been limited by the shallowness of short-wavelength light and the constrained production of ROS. To overcome these limitations, a strategy involves achieving a red shift towards the near-infrared (NIR) light spectrum, promoting the separation and restraining the recombination of electron-hole (e--h+) pairs. Herein, the hybrid plasmonic system Au@ZnO (AZ) with graphene quantum dots (GQDs) doping (AZG) nano heterostructures is rationally designed for optimal NIR-driven cancer treatment. Significantly, a multifold increase in ROS generation can be achieved through the following creative initiatives: (i) plasmonic Au nanorods expands the photocatalytic capabilities of AZG into the NIR domain, offering a foundation for NIR-induced ROS generation for clinical utilization; (ii) elaborate design of mesoporous core-shell AZ structures facilitates the redistribution of electron-hole pairs; (iii) the incorporation GQDs in mesoporous structure could efficiently restrain the recombination of the e--h+ pairs; (iv) Modification of hyaluronic acid (HA) can enhance CD44 receptor mediated targeted triple-negative breast cancer (TNBC). In addition, the introduced Au NRs present as catalysts for enhancing photothermal therapy (PTT), effectively inducing apoptosis in tumor cells. The resulting HA-modified AZG (AZGH) exhibits efficient hot electron injection and e--h+ separation, affording unparalleled convenience for ROS production and enabling NIR-induced PDT for the cancer treanment. As a result, our well-designed mesoporous core-shell AZGH hybrid as photosensitizers can exhibit excellent PDT efficacy.
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Ouro , Grafite , Estresse Oxidativo , Pontos Quânticos , Espécies Reativas de Oxigênio , Neoplasias de Mama Triplo Negativas , Óxido de Zinco , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Humanos , Estresse Oxidativo/efeitos dos fármacos , Feminino , Linhagem Celular Tumoral , Ouro/química , Grafite/química , Óxido de Zinco/química , Animais , Pontos Quânticos/química , Camundongos , Nanopartículas Metálicas/química , Apoptose/efeitos dos fármacos , Ácido Hialurônico/química , ElétronsRESUMO
OBJECTIVE: To establish an ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method for simultaneous determination of 11 nutritional components(thiamine, riboflavin, nicotinamide, nicotinic acid, pantothenic acid, pyridoxine, pyridoxal, pyridoxamine, biotin, choline, L-carnitine) in liquid milk. METHODS: Milk samples were shaken with 20 mmol/L ammonium formate solution and heated in a water bath at 100 â for 30 min, then incubated with papain and acid phosphatase at 45 â for 16 h, the lower liquid was collected after centrifugation for analysis. UPLC separation was performed on an ACQUITY~(TM) HSS T3(3.0 mm×150 mm, 1.8 µm) column, 2 mmol/L ammonium formate(containing 0.1% formic acid) solution and acetonitrile(containing 0.1% formic acid) were used as mobile phase. Quantitative detection was performed by internal standard method. RESULTS: 11 nutritional components can be effectively separated and detected in 12 min, and the linear correlation coefficients(R~2) were all above 0.995. The limits of detection(LODs) were between 0.05 and 0.50 µg/L, and the limits of quantification(LOQs) were between 0.20 and 1.25 µg/L. The recovery rates of three-level addition were 85.6%-119.3%, and the precision RSDs were between 3.68% and 7.82%(n=6). Based on the detection of 60 liquid milk samples from 5 different animals, it was found that the contents of 11 nutrients in liquid milk from different milk sources were significantly different, but pyridoxine could not be detected. CONCLUSION: The method can quantitatively detect 11 water-soluble nutrients, including free and bound forms, by effective enzymolysis. It is sensitive, reproducible and can meet the needs of quantitative detection.
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Leite , Espectrometria de Massas em Tandem , Leite/química , Espectrometria de Massas em Tandem/métodos , Animais , Cromatografia Líquida de Alta Pressão/métodos , Niacinamida/análise , Riboflavina/análise , Nutrientes/análise , Ácido Pantotênico/análise , Bovinos , Piridoxina/análise , Niacina/análise , Carnitina/análiseRESUMO
Piezoelectric material-mediated sonodynamic therapy (SDT) has received considerable research interest in cancer therapy. However, the simple applications of conventional piezoelectric materials do not realize the full potential of piezoelectric materials in medicine. Therefore, the energy band structure of a piezoelectric material is modulated in this study to meet the actual requirement for cancer treatment. Herein, an elaborate PEGylated piezoelectric solid solution 0.7BiFeO3 -0.3BaTiO3 nanoparticles (P-BF-BT NPs) is synthesized, and the resultant particles achieve excellent piezoelectric properties and their band structure is tuned via band engineering. The tuned band structure of P-BF-BT NPs is energetically favorable for the synchronous production of superoxide radicals (â¢O2 - ) and oxygen (O2 ) self-supply via water splitting by the piezoelectric effect. Besides, the P-BF-BT NPs can initiate the Fenton reaction to generate hydroxyl radical (â¢OH), and thus, chemodynamic therapy (CDT) can be augmented by ultrasound. Detailed in vitro and in vivo research has verified the promising effects of multimodal imaging-guided P-BF-BT NP-mediated synergistic SDT/CDT by the piezo-Fenton process in hypoxic tumor elimination, accompanied by high therapeutic biosafety. The current demonstrates a novel strategy for designing and synthesizing "custom-made" piezoelectric materials for cancer therapy in the future.
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Nanopartículas , Neoplasias , Humanos , Engenharia , Radical Hidroxila , Hipóxia , Oxigênio , Linhagem Celular Tumoral , Neoplasias/terapia , Peróxido de HidrogênioRESUMO
Phylogenetic diversity has been widely used to explore diversity patterns and assess processes governing the species composition in community. The estimates of many metrics depend on high-quality data collected from well-designed sampling surveys. However, knowledge of impacts of sampling design on estimation of phylogenetic diversity metrics remains unclear. This study is aim to evaluate the influence of sampling design on phylogenetic diversity metrics estimation of fish community. Simple random sampling (SRS), systematic sampling (SS) and stratified random sampling (StRS) with different sampling intensities were chosen and mean pairwise distances (MPD), mean nearest taxon distance (MNTD), phylogenetic diversity (PD), phylogenetic species variability (PSV), phylogenetic species evenness (PSE) and phylogenetic species richness (PSR) were selected. SRS and StRS showed similar impact on phylogenetic diversity indices estimation and performed relatively well for collecting data to estimate phylogenetic diversity. The accuracy and precision of the estimation increased with sampling intensity under SRS and StRS except SS. MNTD was the only metric not underestimated in four seasons. Metrics strongly influenced by species richness were underestimated when sampling intensity was insufficient. MPD, PSV and PSE showed an obvious seasonal change, which was due to the seasonal differences in fish species composition. In cases where under-sampling is suspected or logistically unavoidable, phylogenetic diversity metrics that are relatively insensitive to sampling design (e.g., MPD and PSV) should be prioritized, especially for exploring the temporal variation in fish community. This study reveals it is indispensable to evaluate sampling design when estimating phylogenetic diversity metrics, especially those indices susceptible to species richness.
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Biodiversidade , Peixes , Animais , Filogenia , Estações do AnoRESUMO
In this study, a peptide-based method employing ultra high performance liquid chromatography electrostatic field orbitrap high-resolution mass spectrometry and triple quadrupole mass spectrometry was developed for quantification of A1-type and A2-type ß-casein in milk from Yak, cows, and their offspring of crosses, Pien-niu. The specific peptides of A1-type and A2-type ß-casein were screened and confirmed by protein software after analysis of high-resolution mass spectrometry. The multiple reaction monitoring method was established based on the qualitative results, and isotope-label peptides were used as internal standards. The linear correlation coefficients of this method were >0.99. The relative standard deviations of repeatability test were 0.2-3.6%. The recovery rate ranged from 93.3 to 114.4% with relative standard deviations <6% at three different spiking levels. The method was applied to analyze 45 milk samples from different species. The results showed that ß-casein in Yak and Pien-niu milk was about 30% higher than that in cow milk. Furthermore, the ß-casein in the Yak milk only contains A2-type ß-casein. A1-type and A2-type ß-casein coexist in most samples of Pien-niu and cow milk, a few samples contain only one type of ß-casein. These results provide further understanding in nutritional value of milk from Yak and Pien-niu.
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Caseínas/análise , Leite/química , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Peptídeos/químicaRESUMO
Acrylamide classified as a probable carcinogen to humans is a high production volume chemical in industrial applications released to aquatic and environmental ecosystems, and also widely found in the thermal processing of starch-rich foods. To gain insight into the urinary metabolomics that may induce physiological responses stimulated by acrylamide, rats were orally administered with a single dose of 13C3-acrylamide (10 mg/kg bw) in the treatment group and urine samples were continuously collected every 2 h during the first 18 h and every 3 h during the period from 18 h to 36 h. A reliable nontargeted screening method for the analysis of urinary metabolomics in rats was developed using ultra-high performance liquid chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry. All metabolites in urine of rats receiving isotope-labeled acrylamide were screened by validated orthogonal partial least squares-discriminant analyses compared to the animals in the control group, while exposure biomarkers were further confirmed according to the characteristic fragmentation rules and time-dependent profiles. Here we identified 2 new specific exposure biomarkers, named N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine-sulfoxide and N-acetyl-S-(2-carboxyl)-L-cysteine, compared to 4 currently acknowledged mercapturic acid adducts of acrylamide. In addition, our findings on analysis of acrylamide metabolic pathway and identification of exposure biomarkers confirmed that acrylamide could significantly affect energy metabolism and amino acid metabolism by the Kyoto Encyclopedia of Genes and Genomes pathway analysis for key metabolites. Homocysteine thiolactone and hypoxanthine may be potential biomarkers for the cardiotoxicity, while methionine sulfoxide, hippuric acid and melatonin may be specifically related to the neurotoxicity. Thus, the current study provided new evidence on the identification of emerging exposure biomarkers and specific signature metabolites related to the toxicity of acrylamide, and shed light on how acrylamide affected energy and amino acid metabolism by further mapping urinary metabolic fingerprints.
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The effects of separation and purification on structural characteristics of polysaccharide from quinoa (Chenopodium quinoa Willd) was investigated. Using quinoa as raw material, the quinoa polysaccharide (QP) was extracted by ultrasonic-assisted method and isolated and purified to obtain three sub-fractions (QPI, QPI-I, QPI-I-I) by resin adsorption, anion-exchange and gel filtration chromatography, respectively. After separation and purification, the polysaccharide content of quinoa polysaccharide increased from 83.29% to 90.12%. XRD and Congo red experiments showed that this process contributed to the formation of crystal structure and triple helix structure. Moreover, the intensity of fourier transform infrared spectroscopy (FT-IR), 1H and 13C Nuclear magnetic resonance spectroscopy (NMR), particle size, dispersion index gradually decreased according to separation and purification, which indicated that a more uniform and stable polysaccharide structure was formed. In addition, FT-IR, 1H NMR and 13C NMR analysis showed that QP, QPI, QPI-I, QPI-I-I were all neutral polysaccharides. The above results suggested that the separation and purification process significantly enhanced the stability of polysaccharide structure. In this process, the aggregation state changed with the polarity change, and the final structure changed, which led to the change of its solubility, viscosity and other physical and chemical properties.
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Chenopodium quinoa/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Tamanho da Partícula , Polissacarídeos/ultraestrutura , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
BACKGROUND AND OBJECTIVES: Breast milk proteins are essential to infants as they provide nutrition and protection. This study evaluated multiple factors that might influence breast milk proteins to identify the determinants that lead to inter-individual and longitudinal differences. METHODS AND STUDY DESIGN: Five major breast milk proteins (ß-casein, α-lactalbumin, lactoferrin, serum albumin and κ-casein) from breast milk samples collected from 55 mothers in three cities (Hohhot, Wuhan and Qingdao) in China were analyzed using a validated ultraperformance liquid chromatography-mass spectrometry method. Various factors were statistically evaluated for their associations with breast milk proteins: mother's age, parity, delivery mode, infant gender and infant birthweight. RESULTS: Although decreased in concentrations, the proportions of ß-casein and α-lactalbumin increased from colostrum (33.8% and 26.8%) to mature milk (40.3% and 31.6%), respectively. Mothers of older age were found to produce a lower concentration of total protein. Compared with vaginal delivery, caesarean section was associated with lower concentrations of κ-casein, lactoferrin and ß-casein in mature milk. Infant gender influenced breast milk proteins in colostrum: mothers who delivered a girl tended to produce more κ-casein, lactoferrin and total protein. Furthermore, regional differences were found, and mothers from Hohhot produced significantly higher concentrations of α-lactalbumin and lactoferrin than those from Qingdao and Wuhan. This regional difference might be linked to the different dietary patterns of these mothers among cities. CONCLUSIONS: Our study deepens the understanding of breast milk protein dynamics in Chinese population and provides evidence on potential determinants, which can serve as guidance for infant nutrition optimization.
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Colostro/química , Parto Obstétrico , Fenômenos Fisiológicos da Nutrição Materna , Proteínas do Leite/química , Leite Humano/química , Adulto , Cesárea , China , Estudos de Coortes , Cultura , Dieta , Feminino , Humanos , Recém-Nascido , Masculino , Proteínas do Leite/metabolismo , Fatores Sexuais , Adulto JovemRESUMO
In recent years, there is an increasing need to measure the concentration of individual proteins in human milk, instead of total human milk proteins. Due to lack of human milk protein standards, there are only few quantification methods established. The objective of the present work was to develop a simple and rapid quantification method for simultaneous determination of α-lactalbumin and ß-casein in human milk using signature peptides according to a modified quantitative proteomics strategy. The internal standards containing the signature peptide sequences were synthesized with isotope-labeled amino acids. The purity of synthesized peptides as standards was determined by amino acid analysis method and area normalization method. The contents of α-lactalbumin and ß-casein in human milk were measured according to the equimolar relationship between the two proteins and their corresponding signature peptides. The method validation results showed a satisfied linearity (R(2)>0.99) and recoveries (97.2-102.5% for α-lactalbumin and 99.5-100.3% for ß-casein). The limit of quantification for α-lactalbumin and ß-casein was 8.0mg/100g and 1.2mg/100g, respectively. CVs for α-lactalbumin and ß-casein in human milk were 5.2% and 3.0%. The contents of α-lactalbumin and ß-casein in 147 human milk samples were successfully determined by the established method and their contents were 205.5-578.2mg/100g and 116.4-467.4mg/100g at different lactation stages. The developed method allows simultaneously determination of α-lactalbumin and ß-casein in human milk. The quantitative strategy based on signature peptide should be applicable to other endogenous proteins in breast milk and other body fluids.
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Caseínas/isolamento & purificação , Lactalbumina/isolamento & purificação , Fragmentos de Peptídeos/análise , Sequência de Aminoácidos , Aminoácidos/química , Isótopos de Carbono , Cromatografia Líquida de Alta Pressão , Humanos , Limite de Detecção , Leite Humano/química , Isótopos de Nitrogênio , Padrões de Referência , Coloração e Rotulagem/métodos , Espectrometria de Massas em TandemRESUMO
The aim of the study was to develop a method for quantification of cow's whey and whole milk powder in goat or sheep milk products including infant formula. A ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was established for simultaneous quantification of four caseins and two major whey proteins by detecting their signature peptides, which were able to act as markers for differentiating goat or sheep from cow whey and whole milk powder in infant formulas. The signature peptides were screened based on the computational prediction by Biolynx software, and confirmed by database searching after analysis of liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry (LC-Q-TOF-MS). The isotopic-labeled signature peptide was used as internal standard to compensate the matrix effect. The limits of quantification were 0.01-0.05 g/100 g for target proteins. The observed recovery rates ranged from 82.3 to 116.6 % and the reproducibility was excellent (RSD <12 %) at different spiking levels. The RSDs of intra- and inter-day precision were 2.8-6.2 and 3.3-9.8 %, respectively. The multiple reaction monitoring method was successfully applied to milk powder with different composition, showing high specificity and accuracy in detection of species involved. The calculating formula was designed to assess the composition of adulteration in the actual detection of infant formulas. These results highlight applicability of this method for the detection of infant formulas with complicated matrix.
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Contaminação de Alimentos/análise , Fórmulas Infantis/química , Proteínas do Leite/análise , Leite/química , Espectrometria de Massas em Tandem/métodos , Proteínas do Soro do Leite/análise , Sequência de Aminoácidos , Animais , Caseínas/análise , Bovinos , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Cabras , Humanos , Recém-Nascido , Limite de Detecção , Ovinos , Espectrometria de Massas por Ionização por Electrospray/métodos , Soro do Leite/químicaRESUMO
A novel pre-treatment was proposed for the simultaneous determination of aflatoxins, ochratoxin A and zearalenone in foodstuffs using high-performance liquid chromatography with fluorescence detection. The analytical procedure was based on a first step using a quick, easy, cheap, effective, rugged, and safe based extraction procedure, followed by salting out and purification with a C18 solid-phase extraction column as interference removal clean-up. Subsequently, collected supernatant was subjected to dispersive liquid-liquid microextraction. Response surface methodology based on central composite design was employed to optimize conditions in the microextraction procedure. Under the optimum conditions, satisfactory analytical performance with recoveries ranging from 63.22 to 107.6% were achieved in different types of cereals and beans, as well as desirable precisions (0.81-8.13%). Limits of detections and quantifications for these six mycotoxins ranging from 0.03 to 13 µg/kg and 0.22 to 44 µg/kg, respectively, were obtained. Finally, the established method was successfully validated by four certified reference materials (P = 0.897 > 0.05) and applied to 79 samples from local markets.
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Grão Comestível/química , Contaminação de Alimentos/análise , Micotoxinas/análise , Cromatografia Líquida de Alta Pressão , Microextração em Fase Líquida , Extração em Fase SólidaRESUMO
Acrylamide is classified as a probable carcinogen to humans and generated from Maillard reaction. Currently, the short-term exposure to acrylamide was evaluated via external diet sources in vitro or two main mercapturic acid metabolites: N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) and N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA) in vivo. In the present work, we comprehensively profiled four mercapturic acid metabolites and evaluated their internal exposure in rats and Chinese adolescents. The cumulative excretion of mercapturic acid metabolites contributes 38.4-73.0 and 43.8-63.6 % of total in vivo metabolites of acrylamide in male and female rats, respectively, when 1, 10, and 50 mg/kg bw of acrylamide were orally administered. Toxicokinetic study revealed that the conversion of acrylamide into glycidamide and glutathione coupling process is highly related to the gender and oral gavage dose via evaluating kinetic parameters, accumulative excretion percentages, and molar ratios of oxidative to reductive metabolism. In human study, a total of 101 Chinese adolescents (41 men and 60 women) were enrolled and served with a meal of potato chips, corresponding to a single-dose (12.6 µg/kg bw) exposure to acrylamide. Toxicokinetic work showed that AAMA is an early and predominant metabolite appearing as a biomarker in urine. N-acetyl-S-(2-carbamoylethyl)-L-cysteine-sulfoxide (AAMA-sul), an oxidative product from AAMA, exhibits a higher peak concentration than GAMA and N-acetyl-S-(1-carbamoyl-2-hydroxyethyl)-L-cysteine (iso-GAMA) during the whole 48-h toxicokinetic period. The internal exposure via four mercapturic acid metabolites is associated with the gender and body mass index characteristics. Thus, current study aims at mercapturic acid metabolites as urinary biomarkers and provides comprehensive insights into the short-term internal exposure to acrylamide.
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Acrilamida/toxicidade , Biomarcadores/urina , Acetilcisteína/análogos & derivados , Acetilcisteína/metabolismo , Acetilcisteína/urina , Acrilamida/farmacocinética , Acrilamida/urina , Animais , Exposição Ambiental , Feminino , Humanos , Masculino , Ratos Sprague-Dawley , Testes de Toxicidade/métodos , Adulto JovemRESUMO
Macronutrient contents in human milk are the common basis for estimating these nutrient requirements for both infants and lactating women. A mid-infrared human milk analyser (HMA, Miris, Sweden) was recently developed for determining macronutrient levels. The purpose of the study is to compare the accuracy and precision of HMA method with fresh milk samples in the field studies with chemical methods with frozen samples in the lab. Full breast milk was collected using electric pumps and fresh milk was analyzed in the field studies using HMA. All human milk samples were thawed and analyzed with chemical reference methods in the lab. The protein, fat and total solid levels were significantly correlated between the two methods and the correlation coefficient was 0.88, 0.93 and 0.78, respectively (p < 0.001). The mean protein content was significantly lower and the mean fat level was significantly greater when measured using HMA method (1.0 g 100 mL-1 vs 1.2 g 100 mL-1 and 3. 7 g 100 mL-1 vs 3.2 g 100 mL-1 , respectively, p < 0.001). Thus, linear recalibration could be used to improve mean estimation for both protein and fat. There was no significant correlation for lactose between the two methods (p > 0.05). There was no statistically significant difference in the mean total solid concentration (12.2 g 100 mL-1 vs 12.3 g 100 mL-1 , p > 0.05). Overall, HMA might be used to analyze macronutrients in fresh human milk with acceptable accuracy and precision after recalibrating fat and protein levels of field samples.
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Leite Humano/química , Valor Nutritivo , Espectrofotometria Infravermelho , Calibragem , Gorduras na Dieta/análise , Feminino , Análise de Alimentos , Humanos , Lactose/análise , Proteínas do Leite/análiseRESUMO
A simple and reliable method of ultra high performance liquid chromatography coupled with photo-diode array detection has been proposed for the simultaneous determination of deoxynivalenol and its acetylated derivatives in wheat flour and rice, especially focusing on the optimization of sample extraction, cleanup, and chromatographic separation conditions. Sample pretreatment consisted of a first step using a quick, easy, cheap, effective, rugged, and safe based extraction procedure and a subsequent cleanup step based on solid-phase extraction. The method was extensively validated in wheat flour and rice, obtaining satisfactory analytical performance with good linearity (R(2) ≥ 0.999), acceptable recoveries (80.0-104.4%), and repeatability (RSDs 1.3-10.7%). The limits of detection (21.7-57.4 µg/kg) and quantitation (72.3-191.4 µg/kg) for deoxynivalenols were lower than those usually permitted by various countries' legislation in these food matrices. The method was applied to 34 wheat and rice samples. The results were further compared with results of ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry.
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Acetilação , Farinha/análise , Oryza/química , Tricotecenos/análise , Zea mays/química , Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
A robust ultra high performance liquid chromatography with tandem mass spectrometry method at peptide level was established for measuring α-lactalbumin in various dairy products. An isotope-labeled winged peptide (VKKILDKVG*INYW*LAHKALCSEKL) with extra amino acids of the sequence of signature peptide concatenated at each end as the internal standard was spiked in samples to participate in the whole tryptic digestion process. The peptide VG*INYW*LAHK that resulted from the isotope-labeled winged peptide was used as the final isotopically labeled internal standard of the α-lactalbumin signature peptide (VGINYWLAHK) during the quantitative analysis. The contents of α-lactalbumin in samples were calculated based on the equimolar relationship between the α-lactalbumin protein and signature peptide. The optimized molar ratio of trypsin to protein (1:60) and enzymatic digestion time (5 h) could not only improve the digestion efficiency and reduce the cost, but also minimize the period of sample pretreatment. Considering the robustness of the current method using the isotopically labeled internal standard and acceptable measurement cost, its application may promote the development of nutrient investigation and quality control of α-lactalbumin in dairy products. This protein analysis method might provide a new reference strategy for food analysis and quantitative protein analysis.