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1.
J Hazard Mater ; 468: 133859, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38402686

RESUMEN

The magnetic properties of lake sediments account for close relationships with heavy metal(loid)s (HMs), but little is known about their relationships with chemical fractions (CFs) of HMs. Establishing an effective workflow to predict HMs risk among various machine learning (ML) methods in conjunction with magnetic measurement remains challenging. This study evaluated the simulation efficiency of nine ML methods in predicting the risk assessment code (RAC) and ratio of the secondary and primary phases (RSP) of HMs with magnetic parameters in sediment cores of a shallow lake. The sediment cores were collected and sliced, and the total amount and CFs of HMs, as well as magnetic parameters, were determined. Support vector machine (SVM) outperformed other models, as evidenced by coefficient of determination (R2) > 0.8. Interpretable machine learning (IML) methods were employed to identify key indicators of RAC and RSP among the magnetic parameters. Values of χARM, HIRM, χARM/χ, and χARM/SIRM of sediments ranging in 220-500 × 10-8 m3/kg, 30-40 × 10-5Am2/kg, 15-25, and 0.5-1, respectively, indicated the potential ecological risks of Cd, Hg, and Sb. This study offers new perspectives on the risk assessment of HMs in lake sediments by combining magnetic measurement with IML workflow.

2.
Anal Bioanal Chem ; 415(8): 1487-1496, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36732370

RESUMEN

A novel matrix certified reference material (CRM) for clenbuterol in mutton (GBW 10216) was developed to assist measurement and risk monitoring of clenbuterol in mutton. The candidate CRM raw samples were obtained by oral administration of clenbuterol and investigating the pharmacokinetics of clenbuterol in sheep. A high-precision isotope dilution coupled with liquid chromatography tandem mass spectrometry (LC-ID-MS/MS) method was established and assigned the value of clenbuterol in mutton powder through combined detection of nine inter-laboratories. The certified value with expanded uncertainty was 21.1 ± 2.2 µg/kg (k = 2, 95% confidence) for clenbuterol in mutton. The prepared matrix CRM was sufficiently homogeneous between and within bottles. The long-term stability of clenbuterol in mutton powder was evaluated for 12 months at -20℃ and short-term stability for 7 days at 4℃ and 50℃. The uncertainties originating from characterization, homogeneity, and stability were systematically analyzed and evaluated. The prepared matrix CRM can be applied for proficiency testing and nationwide risk monitoring programs to guarantee the accuracy and comparability of clenbuterol measurement results in mutton.


Asunto(s)
Clenbuterol , Espectrometría de Masas en Tándem , Animales , Ovinos , Espectrometría de Masas en Tándem/métodos , Clenbuterol/análisis , Estándares de Referencia , Polvos , Cromatografía Liquida/métodos
3.
Chemosphere ; 322: 138205, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36822525

RESUMEN

Sediment cores were collected from Taihu Lake in China. The chronology was determined by radionuclide. Heavy metals and magnetic properties of each core slice were assessed, respectively. The concentrations of most heavy metals in sediments surged at 20 cm from the surface, accompanying the increase in the concentrations of single-domain magnetic particles. This may be resulted from the influence of anthropic activities on the lake's environment after the 1970s. Two feature selection methods, random forest (RF) and maximal information coefficient (MIC), were combined with support vector machine (SVM) model to simulate heavy metals, with the inclusion of selected magnetic and physicochemical parameters. Compared with the modeling results obtained with the full set of parameters, a reasonable simulation performance was obtained with RF and MIC. RF performed better than MIC by increasing the R2 of simulation models for Cd, Cr, Cu, Pb, and Sb. For heavy metals with high ecological risks (As, Cd, Cr, Hg, Pb, Sb), the correlation coefficients for observed and predicted data ranged from 0.73 to 0.97 with only 14-27% of the parameters selected by RF as input variables. The RF-RBF-SVM enabled heavy metal predictions based on the magnetic properties of the lake sediments.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Cadmio , Plomo , Sedimentos Geológicos/química , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Metales Pesados/análisis , Lagos/química , China , Aprendizaje Automático , Medición de Riesgo
4.
Artículo en Inglés | MEDLINE | ID: mdl-35838334

RESUMEN

Some florfenicol (FF) metabolites have a strong binding affinity towards biomolecules in the edible tissues of some food animals. These bound FF residues cannot be extracted directly from edible tissues with organic solvents and are present in higher concentrations even than solvent extractable residues. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established to detect the total residues of FF in eggs, by quantifying the metabolite florfenicol amine (FFA). The sample was hydrolyzed at 95-100 °C for 4 hours to release sample-matrix bound residues and convert them all into FFA. The hydrolyzed sample was washed with ethyl acetate to remove interfering substances, extracted with ethyl acetate under alkaline conditions, purified by solid phase extraction and quantified by UPLC-MS/MS. The recoveries of FFA in eggs ranged from 91.2 to 102.4%, with an RSD ≤ 10.9%. The LOD and LOQ were 0.5 and 1.0 µg/kg, respectively. This method can be applied to the quantification of total FF residues in eggs.


Asunto(s)
Residuos de Medicamentos , Tianfenicol , Animales , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida/métodos , Residuos de Medicamentos/análisis , Solventes/química , Espectrometría de Masas en Tándem/métodos , Tianfenicol/análogos & derivados
5.
RSC Adv ; 12(26): 16790-16797, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35754881

RESUMEN

Peanut is an important crop grown worldwide. The geographic origin of peanuts has been a topic of substantial attention since their prices can vary according to their geographic origins. This study evaluated the main macro (K, Ca, Mg, Na, and Al), micro (Fe, Zn, Mn, Ni, Sr, Mo, Cu, Se, V, Co), and toxic (As, Cd, Cr, and Pb) element concentrations in peanuts collected from six different Chinese provinces. Multi-element analysis of peanuts from different regions was carried out to develop a reliable method to trace the origin of peanuts. After microwave digestion, the element concentrations were determined through inductively coupled plasma mass spectrometry (ICP-MS). Certified reference material (CRM, GBW10011) was used to ensure accurate results. The profile of contents of major elements obtained in the current study showed the order: K > Mg > Ca > Al > Na > Zn > Fe > Mn > Ni > Sr > Mo. The average concentrations of toxic elements such as Pb, Cd, As, and Cr were very low and within the safe limits. Correlation analysis showed that there was a strong correlation between individual elements in peanut samples. The data were processed by means of the chemometric approach of linear discriminant analysis (LDA) and 97.0% of samples were correctly predicted.

6.
Sci Total Environ ; 836: 155655, 2022 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-35526622

RESUMEN

Microplastics (plastic particles < 5 mm; MPs) are ubiquitous in aquatic environments but their potential adverse ecological effects on biota remain poorly understood. This is in part because in typical ecotoxicology tests the toxic effects of MPs were found to be limited. To capture the potential find-scale effects of MPs on freshwater organisms, we employed ultra-performance liquid chromatography-tandem mass spectrometry based untargeted metabolomics to investigate the metabolic impact of polystyrene microbeads microplastics (PS-MPs) of different sizes (0.1, 1, 10, 100 µm) and concentrations (1, 10, 100 mg/L) on a common freshwater microalga, Microcystis aeruginosa, after a 96-h exposure test. The phenotype-based results illustrated that while PS-MPs had no discernible effects on microalgal growth and photosynthesis, both oxidative stress and microcystin production were slightly increased. Metabolomics analysis revealed that the PS-MPs altered the global metabolic profile of the microalga. Specially, PS-MPs of larger size and higher concentration induced a larger number of differentially expressed metabolites. The PS-MPs significantly disturbed metabolisms involved in amino acid synthesis, membrane formation, nitrogen storage, and antioxidant defense of the microalga, consistent with the phenotypic observations. These results suggested several perturbed metabolic pathways, especially arginine-related pathways, as the mechanism. Our study showed that the insights provided by metabolomics-based approaches can enhance assessments of the ecological impacts of MPs on freshwater organisms.


Asunto(s)
Microalgas , Microcystis , Contaminantes Químicos del Agua , Organismos Acuáticos/metabolismo , Agua Dulce , Microplásticos/toxicidad , Plásticos/toxicidad , Poliestirenos/metabolismo , Poliestirenos/toxicidad , Contaminantes Químicos del Agua/metabolismo
7.
Water Res ; 212: 118116, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35114532

RESUMEN

Microplastics contamination in the environment is a global problem, but little is known about their dynamics in urban river networks, an important site of microplastics occurrence and harboring complex transport pathways. In this study, we investigated the spatiotemporal dynamic of microplastics in a typical urban river network in eastern China from December 2018 to September 2019. microplastics abundance (mean ± standard deviation) in the river network ranged from 2.3 ± 1.2 to 104.6 ± 5.6 particles/L and was significantly higher during the wet than during the dry season. The distribution of microplastics in the upper, middle, and lower reaches of the river network did not significantly differ, nor did the abundance of microplastics in the surface water vs. the bottom water. However, high abundances were determined in commercial and industrial areas, at a wastewater treatment plant outlet, in an urban canal, and in an urban-rural fringe area. The seasonal dynamics of the overall abundance of microplastics could be explained by the hysteresis effect of urban plastic production and the variation in regional precipitation. 78.2% of the microplastics were < 330 µm in size; the most common colors were blue and black, and the most common shapes were fragments and fibers. The polymer types of the microplastics were assessed using laser direct infrared (LDIR), a novel chemical imaging system that identified silicone, rubber, polytetrafluoroethylene, and polypropylene as the main components of the microplastics. A non-metric multidimensional scaling analysis (NMDS) based on the abundance of the polymer components across samples showed aggregations of sampling sites, that indicated the possible sources of the microplastics. Our study provides insights into the spatiotemporal dynamics of microplastics in an urban river network and suggests the potential of LDIR in the accurate quantitative analysis of microplastics in the environment.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Plásticos , Ríos , Contaminantes Químicos del Agua/análisis
8.
J Immunother Cancer ; 9(7)2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34244308

RESUMEN

BACKGROUND: Neoantigen (NeoAg) peptides displayed at the tumor cell surface by human leukocyte antigen molecules show exquisite tumor specificity and can elicit T cell mediated tumor rejection. However, few NeoAgs are predicted to be shared between patients, and none to date have demonstrated therapeutic value in the context of vaccination. METHODS: We report here a phase I trial of personalized NeoAg peptide vaccination (PPV) of 24 stage III/IV non-small cell lung cancer (NSCLC) patients who had previously progressed following multiple conventional therapies, including surgery, radiation, chemotherapy, and tyrosine kinase inhibitors (TKIs). Primary endpoints of the trial evaluated feasibility, tolerability, and safety of the personalized vaccination approach, and secondary trial endpoints assessed tumor-specific immune reactivity and clinical responses. Of the 16 patients with epidermal growth factor receptor (EGFR) mutations, nine continued TKI therapy concurrent with PPV and seven patients received PPV alone. RESULTS: Out of 29 patients enrolled in the trial, 24 were immunized with personalized NeoAg peptides. Aside from transient rash, fatigue and/or fever observed in three patients, no other treatment-related adverse events were observed. Median progression-free survival and overall survival of the 24 vaccinated patients were 6.0 and 8.9 months, respectively. Within 3-4 months following initiation of PPV, seven RECIST-based objective clinical responses including one complete response were observed. Notably, all seven clinical responders had EGFR-mutated tumors, including four patients that had continued TKI therapy concurrently with PPV. Immune monitoring showed that five of the seven responding patients demonstrated vaccine-induced T cell responses against EGFR NeoAg peptides. Furthermore, two highly shared EGFR mutations (L858R and T790M) were shown to be immunogenic in four of the responding patients, all of whom demonstrated increases in peripheral blood neoantigen-specific CD8+ T cell frequencies during the course of PPV. CONCLUSIONS: These results show that personalized NeoAg vaccination is feasible and safe for advanced-stage NSCLC patients. The clinical and immune responses observed following PPV suggest that EGFR mutations constitute shared, immunogenic neoantigens with promising immunotherapeutic potential for large subsets of NSCLC patients. Furthermore, PPV with concurrent EGFR inhibitor therapy was well tolerated and may have contributed to the induction of PPV-induced T cell responses.


Asunto(s)
Vacunas contra el Cáncer/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Vacunas contra el Cáncer/farmacología , Carcinoma de Pulmón de Células no Pequeñas/patología , Receptores ErbB/metabolismo , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Mutación
9.
Mar Pollut Bull ; 161(Pt A): 111656, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33022496

RESUMEN

Polyhalogenated carbazoles (PHCZs), a novel type of organic pollutants with dioxin-like toxicity, have gained increasing attention in the past several years. In this study detection and distribution of five PHCZ compounds found in the Yellow Sea region are studied. The range of ∑PHCZ in the detection area is 0.062-0.322 ng/L (median: 0.112 ng/L), with 3,6-dichlorocarbazole and 3,6-dibromocarbazole content being the greatest, ranging from 0.035-0.269 ng/L and 0.010-0.682 ng/L, respectively, followed by 3-CCZ (0.010-0.020 ng/L). The relative toxicity of PHCZs is evaluated by the toxicity equivalent (TEQ), in which a range of 0-0.19 pgTEQ/L (median: 0.006 pgTEQ/L) is determined. According to the results, PHCZs are widely distributed in Yellow Sea water with relatively lower toxicity, and the impact of natural factors, as well as their potential sources, are discussed in order to provide basic scientific data for the investigation of PHCZs in seawater.


Asunto(s)
Dioxinas , Contaminantes Químicos del Agua , Carbazoles/análisis , China , Medición de Riesgo , Agua de Mar , Contaminantes Químicos del Agua/análisis
10.
Artículo en Inglés | MEDLINE | ID: mdl-32619394

RESUMEN

In this study, we carried out two experiments to evaluate depletion of florfenicol (FF) and its metabolite florfenicol amine (FFA) in eggs from growing pullets and laying hens. Eggs were collected, and the egg white and yolk were separated. FF and FFA were analysed by liquid chromatography-tandem mass spectrometry. In the first experiment, 30 laying hens were given FF capsules at 50 mg/kg·bw-1 daily for 5 d. FF + FFA was detectable in egg white (1,190 µg/kg) on day 1 of treatment and increased slowly thereafter. After treatment, the residues decreased rapidly and were not detected by day 11. In yolk, residues were detected at a lower concentration on day 1 and increased dramatically to 3308 µg/kg at the end of treatment. The residues remained steady over the next 4 days post-treatment, followed by a rapid drop. Residues were not detectable on day 15 post-treatment. In the second experiment, four groups (B1 through B4) of growing pullets were treated in the same manner for 25, 20, 15, and 10 days before egg primiparity. FF and FFA were not detectable in the eggs of group B1; however, they were detectable in egg whites and yolks of groups B2, B3, and B4. The highest total concentrations of FF and FFA detected in egg white and yolk of group B4 were 3,190 µg/kg and 3,214 µg/kg, respectively. Thereafter, concentrations decreased until no more residues were detected in egg whites or yolks on days 17 and 21 post-treatment, respectively. Therefore, drug treatment should be stopped at least 21 d before primiparity of growing pullets to guarantee food safety.


Asunto(s)
Antibacterianos/análisis , Clara de Huevo/química , Yema de Huevo/química , Huevos/análisis , Tianfenicol/análogos & derivados , Administración Oral , Animales , Antibacterianos/administración & dosificación , Pollos , Tianfenicol/administración & dosificación , Tianfenicol/análisis
11.
Mediators Inflamm ; 2020: 5821428, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32189994

RESUMEN

Inflammation and oxidative stress play key roles in the process of aging and age-related diseases. Since serine availability plays important roles in the support of antioxidant and anti-inflammatory defense system, we explored whether serine deficiency affects inflammatory and oxidative status in D-galactose-induced aging mice. Male mice were randomly assigned into four groups: mice fed a basal diet, mice fed a serine- and glycine-deficient (SGD) diet, mice injected with D-galactose and fed a basal diet, and mice injected with D-galactose and fed an SGD diet. The results showed that D-galactose resulted in oxidative and inflammatory responses, while serine deficiency alone showed no such effects. However, serine deficiency significantly exacerbated oxidative stress and inflammation in D-galactose-treated mice. The composition of fecal microbiota was affected by D-galactose injection, which was characterized by decreased microbiota diversity and downregulated ratio of Firmicutes/Bacteroidetes, as well as decreased proportion of Clostridium XIVa. Furthermore, serine deficiency exacerbated these changes. Additionally, serine deficiency in combination with D-galactose injection significantly decreased fecal butyric acid content and gene expression of short-chain fatty acid transporters (Slc16a3 and Slc16a7) and receptor (Gpr109a) in the brain. Finally, serine deficiency exacerbated the decrease of expression of phosphorylated AMPK and the increase of expression of phosphorylated NFκB p65, which were caused by D-galactose injection. In conclusion, our results suggested that serine deficiency exacerbated inflammation and oxidative stress in D-galactose-induced aging mice. The involved mechanisms might be partially attributed to the changes in the microbiota-gut-brain axis affected by serine deficiency.


Asunto(s)
Galactosa/farmacología , Inflamación/metabolismo , Estrés Oxidativo/fisiología , Animales , Western Blotting , Clostridium/fisiología , Firmicutes/fisiología , Microbioma Gastrointestinal/genética , Microbioma Gastrointestinal/fisiología , Glicina/deficiencia , Inflamación/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/genética , Serina/deficiencia , Factor de Transcripción ReIA/metabolismo
12.
Artículo en Inglés | MEDLINE | ID: mdl-32148551

RESUMEN

Major depressive disorder (MDD), especially combined with anxiety, has a high incidence and low detection rate in China. Literature has shown that patients under major depression with anxiety (MDA) are more likely to nominate a somatic, rather than psychological, symptom as their presenting complaint. In the theory of Traditional Chinese Medicine (TCM), clinical symptoms of MDD patients are mainly categorized into two different syndrome patterns: Deficiency and Excess. We intend to use resting-state functional magnetic resonance imaging (rs-fMRI) to investigate their brain functional differences and hopefully to find their brain function mechanism. For our research, 42 drug-naive MDA patients were divided into two groups (21 for Deficiency and 21 for Excess), with an additional 19 unaffected participants in the normal control (NC) group. We took Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale (HAMA), and brain fMRI scan for each group and analyzed the data. We first used Degree Centrality (DC) to map the functional differences in brain regions, utilized these regions as seed points, and used a seed-based functional connectivity (FC) analysis to identify the specific functional connection between groups. The Deficiency group was found to have higher HAMD scores, HAMA scores, and HAMD somatic factor than the Excess group. In the DC analysis, significant decreases were found in the right precuneus of both the Deficiency and Excess groups compared to the NC group. In the FC analysis, the right precuneus showed significant decreased network connectivity with the bilateral cuneus, as well as the right lingual gyrus in the Deficiency group when compared to the NC group and the Excess group. Through our research, it was found that precuneus dysfunction may have a relationship with MDA and Deficiency patients have more severe physical and emotional symptoms, and we realized that a larger sample size and multiple brain mode observations were needed in further research.

13.
Molecules ; 25(3)2020 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-31979297

RESUMEN

The experiment developed the ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) method for testing emamectin benzoate, and studied the metabolism of emamectin benzoate in rice plants and rice-growing environments via application of this testing method. The dissipation curve of emamectin benzoate standard substance was good at 0.5-200 µg L-1, and its correlation coefficient was greater than 0.99. In the concentration range of 0.1-50 µg kg-1, the average recovery rate of plants, soil, and field water was 82 %-102 %, and relative standard deviation (RSD) was between 0.3 % and 15.9 %. Half-lives in rice plants and soil were 0.8-2.8 days and 1.9-3.8 days, respectively, and emamectin benzoate was not detected in rice or rice hull. The experiment showed that emamectin benzoate is harmless to human health at the concentration recommended by the manufacturer.


Asunto(s)
Cromatografía Liquida/métodos , Ivermectina/análogos & derivados , Oryza/química , Residuos de Plaguicidas/análisis , Suelo/química , Espectrometría de Masas en Tándem/métodos , Monitoreo del Ambiente/métodos , Ivermectina/química , Ivermectina/metabolismo , Tallos de la Planta/química , Sensibilidad y Especificidad
14.
RSC Adv ; 10(12): 6736-6742, 2020 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-35493914

RESUMEN

We analyzed the concentrations of 17 elements including arsenic (As), lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), strontium (Sr), tin (Sn), aluminum (Al), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), sodium (Na), and selenium (Se) in cow, goat, buffalo, yak, and camel milk in China using inductively coupled plasma mass spectrometry. The concentrations of the elements varied and depended on the milk type. K, Ca, Na, and Mg were the most abundant elements. Fe and Zn concentrations ranged from 1 to 6 µg g-1, while Cu, Al, and Mn concentrations ranged from 0.1 to 1 µg g-1. Trace elements, especially toxic trace elements, were present at very low concentrations; however, Pb concentrations in cow milk reached the MRLs established by the Codex Alimentarius Commission. Data were analyzed by chemometrics to evaluate the correlations between elements in the milk samples. PCA and factor analysis highlighted the relationship between element distribution and milk type. The LDA model correctly identified most milk types. Element analysis combined with chemometrics can be used to distinguish milk types.

15.
Sci Rep ; 9(1): 19609, 2019 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-31844083

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

16.
Molecules ; 24(22)2019 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-31752401

RESUMEN

An ultrahigh-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of lactoferrin in camel milk based on the signature peptide. The camel lactoferrin was purified by heparin affinity chromatography and then used to screen tryptic signature peptides. The signature peptide was selected on the basis of sequence database search and identified from the tryptic hydrolysates of purified camel lactoferrin by ultrahigh-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry. The pretreatment procedures included the addition of isotope-labeled winged peptide and the disposal of lipids and caseins followed by an enzymatic digestion with trypsin. Analytes were separated on an Acquity UPLC BEH 300 C18 column and then detected on a triple-quadrupole mass spectrometer in 7 min. The limits of detection and quantification were 3.8 mg kg-1 and 11 mg kg-1, respectively. The recoveries ranged from 74.5% to 103.6%, with relative standard deviations below 7.7%. The validated method was applied to determine the lactoferrin in ten samples collected from Xinjiang Province.


Asunto(s)
Cromatografía Líquida de Alta Presión , Marcaje Isotópico , Lactoferrina/análisis , Leche/química , Péptidos/química , Espectrometría de Masas en Tándem , Animales , Camelus , Análisis de los Alimentos , Péptidos/análisis , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
Metabolites ; 9(8)2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31374906

RESUMEN

Rapeseed is an important oilseed with proper fatty acid composition and abundant bioactive components. Canada and China are the two major rapeseed-producing countries all over the world. Meanwhile, Canada and Mongolia are major importers of rapeseed due to the great demand for rapeseed in China. To investigate the metabolites in rapeseeds from three countries, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based metabolomics was employed to analyze rapeseeds from China, Canada, and Mongolia. As results, 67, 53, and 68 metabolites showed significant differences between Chinese and Canadian, Chinese and Mongolian, and Canadian and Mongolian rapeseeds, respectively. Differential metabolites were mainly distributed in the metabolic pathways including phenylpropanoid biosynthesis, flavone and flavonol biosynthesis, and ubiquinone and other terpenoid-quinone biosynthesis. Among the differential metabolites, contents of sinapate and sinapine were higher in Chinese rapeseeds, while the contents of brassicasterol, stigmasterol, and campestanol were higher in Canadian rapeseeds. These findings might provide insight into the metabolic characteristics of rapeseeds from three countries to guide processing and consumption of the products of rapeseed.

18.
Sci Rep ; 9(1): 8510, 2019 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-31186462

RESUMEN

This study was aimed to identify the chemical compounds of Aedes aegypti that can be potentially used to develop pheromone-based vector control methods. In this study, we compared the chemical compounds collected from the organs of mosquitoes at different developmental stages in the life cycle. We also compared the composition and amount of extracts from the different tissues of male and female adult mosquito. Interestingly, we found large amount of C17-C20 ethyl and methyl esters in the wings of female and antennae of male mosquito. We also found that isopropyl esters, dodelactone, octadecenoic acid and medium-chain fatty acid increase drastically during the late larval stage (L4). Old adult mosquitoes showed remarkable increase in production of C16:1 and C18:1 methyl esters, as a first example of chemical signatures specifically associated with aging in the animals. This knowledge may open the ground to find new behaviorally-important molecules with the ability to control Aedes specifically.


Asunto(s)
Aedes/virología , Dengue/parasitología , Mosquitos Vectores/virología , Odorantes/análisis , Aedes/crecimiento & desarrollo , Animales , Femenino , Masculino , Compuestos Orgánicos Volátiles/análisis
19.
Protein Expr Purif ; 138: 46-55, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28711731

RESUMEN

Insulin chains are usually expressed in Escherichia coli as fusion proteins with different tags, including various low molecular weight peptide tags. The objective of this study was to determine if insulin chains could facilitate the recombinant expression of other target proteins, with an emphasis on low molecular weight peptides. A series of short peptides were fused to mini-proinsulin, chain B or chain A, and induced for expression in Escherichia coli. All the tested peptides including glucagon-like peptide 1 (GLP-1), a C-terminal extended GLP-1, oxyntomodulin, enfuvirtide, linaclotide, and an unstructured artificial peptide were expressed with reasonable yields, identified by Tricine-SDS-PAGE and immunoblotting. All recombinant products were expressed in inclusion bodies. The effective accumulation of products was largely attributed to the insoluble expression induced by fusion with insulin chains, and was confirmed by the fusion expression of transthyretin. Insulin chains thus show promise as efficient fusion tags for mass production of heterologous peptides in prokaryotes.


Asunto(s)
Vectores Genéticos/metabolismo , Péptido 1 Similar al Glucagón/genética , Proteína gp41 de Envoltorio del VIH/genética , Fragmentos de Péptidos/genética , Péptidos/genética , Proinsulina/genética , Proteínas Recombinantes de Fusión/genética , Secuencia de Aminoácidos , Western Blotting , Clonación Molecular , Electroforesis en Gel de Poliacrilamida , Enfuvirtida , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Vectores Genéticos/química , Péptido 1 Similar al Glucagón/aislamiento & purificación , Péptido 1 Similar al Glucagón/metabolismo , Proteína gp41 de Envoltorio del VIH/aislamiento & purificación , Proteína gp41 de Envoltorio del VIH/metabolismo , Humanos , Cuerpos de Inclusión/química , Peso Molecular , Fragmentos de Péptidos/aislamiento & purificación , Fragmentos de Péptidos/metabolismo , Péptidos/aislamiento & purificación , Péptidos/metabolismo , Prealbúmina/genética , Prealbúmina/aislamiento & purificación , Prealbúmina/metabolismo , Proinsulina/aislamiento & purificación , Proinsulina/metabolismo , Proteínas Recombinantes de Fusión/aislamiento & purificación , Proteínas Recombinantes de Fusión/metabolismo , Temperatura
20.
Luminescence ; 31(2): 462-467, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26250149

RESUMEN

The antimonate compound La3SbO7 has high chemical stability, lattice stiffness and thermal stability. Orange-red-emitting antimonate-based phosphors La3SbO7:xSm(3+) (x = 0.02, 0.05, 0.08, 0.10, 0.15, 0.20 and 0.25) were synthesized. The phase structure and photoluminescence properties of these phosphors were investigated. The emission spectrum obtained on excitation at 407 nm contained exclusively the characteristic emissions of Sm(3+) at 568, 608, 654 and 716 nm, which correspond to the transitions from (4)G5/2 to (6)H5/2, (6)H7/2, (6)H9/2 and (6)H11/2 of Sm(3+), respectively. The strongest emission was located at 608 nm due to the (4)G5/2→(6)H7/2 transition of Sm(3+), generating bright orange-red light. The critical quenching concentration of Sm(3+) in La3SbO7:Sm(3+) phosphor was determined as 10% and the energy transfer between Sm(3+) was found to be through an exchange interaction. The International Commission on Illumination chromaticity coordinates of the La3SbO7:0.10Sm(3+) phosphors are located in the orange-red region. The La3SbO7:Sm(3+) phosphors may be potentially used as red phosphors for white light-emitting diodes.


Asunto(s)
Antimonio/química , Lantano/química , Luminiscencia , Oxígeno/química , Samario/química , Procesos Fotoquímicos
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