Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50
Filtrar
1.
Electrophoresis ; 2022 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-35562841

RESUMO

Sorghum is an important grain with high economic value for liquor producing. Tracing the geographical origin of sorghum is vital to guarantee the liquor flavor. Soldering iron based rapid evaporative ionization mass spectrometry(REIMS) combined with chemometrics was developed for real-time discrimination of the sorghum geographical origin. The working conditions of soldering iron based ionization was optimized and then the obtained MS profiling data was processed using chemometrics analysis methods including principal component analysis-linear discriminate analysis (PCA-LDA) and orthogonal projection to latent structures discriminant analysis (OPLS-DA). A recognition model was established and discrimination of sorghum samples from10 provinces in China were achieved with correct rate higher than 90%. On the basis of OPLS-DA, the specific ions of m/z 279.2327, 281.2479 and 283.2639 had relatively strong discrimination power for the geographical origins of sorghum. The developed method was successfully applied in the discrimination of sorghum origins. The results indicated that the soldering iron based REIMS technique combined with chemometrics is a useful tool for direct, fast and real-time ionization of poor conductivity samples and acquisition of metabolic profiling data. This article is protected by copyright. All rights reserved.

2.
Anal Chem ; 94(18): 6719-6727, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35475631

RESUMO

Discovering the fungus-infected or mycotoxin-contaminated biomarkers is significant for systems biology since the metabolites in biological samples have significant polarity differences in both stochastic gene expression and microenvironmental change. Here, we aim to establish a comprehensive method for a lipidome by ion mobility mass spectrometry (IMS) merged with chemometrics to accurately find out the more scientific markers of cell interference by mycotoxins and for pathogenesis exploration and drug development. The differences in the abundances of several small molecules found in these metabolites were explored through multivariate statistical analysis, including principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA), to further screen biomarkers. Good applicability and predictability were demonstrated by R2(X) and Q2 (R2 = 0.959, Q2 = 0.999). Five compounds with m/z values of 512.502 8, 540.5343, 722.525 8, 787.667 5, and 813.683 0 were selected as markers, and four of them were further confirmed by chemical standards (i.e., MSMS of m/z 813.683 0 covering m/z 86.0978, 125.0008, 184.0745, and 185.0781). In summary, we demonstrated the integration of UPLC-TOF-IMS and the chemometrics approach to elucidate identified biomarkers, which also provides a new way of thinking for covering lipid biomarkers or prognostic indicators for mycotoxins.


Assuntos
Lipidômica , Micotoxinas , Biomarcadores , Cromatografia Líquida de Alta Pressão/métodos , Células Hep G2 , Humanos , Metabolômica/métodos
3.
Angew Chem Int Ed Engl ; 61(7): e202111151, 2022 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-34873818

RESUMO

Manipulation of cell-cell interactions via cell surface engineering has potential biomedical applications in tissue engineering and cell therapy. However, manipulation of the comprehensive and multiple intercellular interactions remains a challenge and missing elements. Herein, utilizing a DNA triangular prism (TP) and a branched polymer (BP) as functional modules, we fabricate tunable DNA scaffold networks on the cell surface. The responsiveness of cell-cell recognition, aggregation and dissociation could be modulated by aptamer-functionalized DNA scaffold networks with high accuracy and specificity. By regulating the DNA scaffold networks coated on the cell surface, controlled intercellular molecular transportation is achieved. Our tunable network provides a simple and extendible strategy which addresses a current need in cell surface engineering to precisely manipulate cell-cell interactions and shows promise as a general tool for controllable cell behavior.


Assuntos
DNA/química , Redes Neurais de Computação , Polímeros/química , Comunicação Celular , Células HeLa , Células Hep G2 , Humanos
4.
Int J Surg Pathol ; 30(1): 15-22, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34255581

RESUMO

Primary urothelial carcinoma (UCa) of the urethra is relatively uncommon, and the underlying pathogenesis has not been well characterized, especially in the absence of concurrent UCa at other sites. A search for cases of primary UCa of the urethra was conducted. Patients with concurrent UCa of the renal pelvis, ureter, or bladder at the time of diagnosis of the primary tumor were excluded. Clinicopathologic and follow-up data were obtained. A total of 35 cases from 30 patients (27 male and 3 female) were included in the study. The mean patient age at the initial diagnosis was 71 years (range: 41-90 years). Cases were composed of high-grade UCa (26 of 35 = 74%), low-grade UCa (4 of 35 = 11%), and UCa in situ (5 of 35 = 14%). Invasion was present in 14 of 26 (54%) cases of high-grade UCa. Interestingly, 23 of 30 (77%) patients had a previous history of UCa including 7 (30%) cases with divergent differentiation or variant histology. Follow-up data were available in 23 patients with a mean duration of 26.7 months (range: 0.6-87 months). Eleven patients (31%) died of metastatic UCa. This is one of the largest studies to date of primary UCa of the urethra without concurrent UCa of the renal pelvis, ureter, or bladder. Previous history of UCa of the bladder, especially with divergent differentiation or variant histology is conceivably a key risk factor for developing subsequent primary UCa of the urethra. These findings are important for the development of surveillance protocols and therapeutic strategies.


Assuntos
Carcinoma de Células de Transição/patologia , Neoplasias Uretrais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células de Transição/diagnóstico , Carcinoma de Células de Transição/mortalidade , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias Uretrais/diagnóstico , Neoplasias Uretrais/mortalidade
5.
J Phys Chem Lett ; 12(44): 10753-10760, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34714072

RESUMO

Group-VA two-dimensional layered materials in a puckered honeycomb structure exhibit strong in-plane anisotropy and have emerged as new platforms for novel devices. Here, we report on systematic Raman investigations on exfoliated b-As flakes on the Ag1 and Ag2 polarization dependence on their symmetry, excitation wavelength, and flake thickness. The intensity maximums of both phonons are corrected in the b-As armchair direction under 633 nm excitation regardless of the flake thickness upon considering optical birefringence effects and interference effects. The intensity ratio of Ag1 to Ag2 modes under 532 nm excitation is useful for b-As crystalline orientation identification. Temperature-dependent Raman investigations reveal the linearly anharmonic behaviors of both phonons in the range from 173 to 293 K and a slightly greater first-order temperature coefficient in the zigzag direction. Our findings give deep insight into the in-plane phonon anisotropy and anharmonicity of b-As and provide a step toward future device applications.

6.
Anal Bioanal Chem ; 413(28): 7021-7030, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34642779

RESUMO

Understanding the spatial distribution of bioactive small molecules is indispensable for elucidating their biological or pharmaceutical roles. Here, a rapid and effective analysis strategy was introduced to study the distribution of veterinary drugs in aquatic products. Malachite green (MG), one of the most widely used veterinary drugs in aquaculture, was selected as the targeted compound. Zebrafish (Danio rerio) was used as a model organism. After an exposure test, the matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) technique was applied to directly analyze the content changes of malachite green in zebrafish tissues. The reliable relationship of exposure time and content change of MG was described precisely by the extended Freundlich equation. The process of modeling was discussed in detail, and some important parameters or trend information was obtained, including the maximum content of MG in different fish tissues, time to maximum content, elimination time, equilibrium content, and so on. With a simplification of sample pretreatment, this research strategy can be used for monitoring the spatial distribution of veterinary drugs and related metabolites of laboratory-exposed fish. The obtained model can provide a perspective for rational drug use in aquaculture and precise drug residue detection in production activities.


Assuntos
Corantes de Rosanilina/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Modelos Químicos , Padrões de Referência , Corantes de Rosanilina/normas , Peixe-Zebra
7.
Mikrochim Acta ; 188(8): 246, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34235593

RESUMO

Magnetic covalent organic framework nanocomposite denoted as Fe3O4@TAPB-Tp with core-shell structure was fabricated via a simple template-mediated precipitation polymerization method at mild conditions. The polyimine network shell was created through the polymerization of 1,3,5-tris(4-aminophenyl)-benzene (TAPB) and 1,3,5-triformyl-phloroglucinol (Tp) in tetrahydrofuran (THF) by the Schiff-base reaction. Featuring with large specific surface area (163.19 m2 g-1), good solution dispersibility, and high stability, the obtained Fe3O4@TAPB-Tp exhibited high adsorption capacities and fast adsorption for zearalenone and its derivatives (ZEAs). The adsorption isotherms showed multilayer adsorption dominated at low concentration and monolayer adsorption at high concentration between the interface of ZEAs and Fe3O4@TAPB-Tp. With the Fe3O4@TAPB-Tp as sorbent, a magnetic solid-phase extraction-ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was established for simultaneous adsorption and detection of five ZEAs in complex samples. The proposed method displayed favorable linearity, low limits of detection (0.003 ~ 0.018 µg kg-1), and good repeatability (2.37~10.4%). The developed method has been applied for real sample analysis, with recoveries of 81.27~90.26%. These results showed that Fe3O4@TAPB-Tp has a good application potential for the adsorption of ZEAs in food samples. Magnetic covalent organic framework nanocomposite (Fe3O4@TAPB-Tp) were quickly fabricated at mild conditions and used as effective adsorbent for magnetic solid-phase extraction of zearalenone and its derivatives (ZEAs) from food samples prior to ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis.


Assuntos
Nanopartículas de Magnetita/química , Estruturas Metalorgânicas/química , Micotoxinas/análise , Zearalenona/análise , Adsorção , Animais , Derivados de Benzeno/química , Cromatografia Líquida de Alta Pressão , Ovos/análise , Contaminação de Alimentos/análise , Limite de Detecção , Fenômenos Magnéticos , Leite/química , Micotoxinas/química , Micotoxinas/isolamento & purificação , Nanocompostos/química , Floroglucinol/análogos & derivados , Floroglucinol/química , Polimerização , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem , Zea mays , Zearalenona/análogos & derivados , Zearalenona/isolamento & purificação
8.
J Agric Food Chem ; 69(20): 5709-5724, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-33955749

RESUMO

An intelligent surgical knife (iKnife) coupled with rapid evaporative ionization mass spectrometry (REIMS) was employed for the lipidomic profiling of fresh and frozen-thawed beef muscle. The data were obtained by REIMS and then processed using multivariate statistical analysis methods including principal component analysis-linear discriminant analysis (PCA-LDA) and orthogonal partial least-squares discriminant analysis (OPLS-DA). The discrimination of fresh and frozen-thawed meat has been achieved, and the real-time identification accuracy was 92-100%. Changes in the composition and content of fatty acids and phospholipids were statistically analyzed by OPLS-DA, and the ions of m/z 279.2317, m/z 681.4830, and m/z 697.4882 were selected as differential compounds/metabolites. The developed method was also successfully applied in the discrimination of fresh and frozen-thawed meat samples. These results showed that REIMS as a high-throughput, rapid, and real-time mass spectrometry detection technology can be used for the identification of fresh and frozen-thawed meat samples.


Assuntos
Carne , Músculos , Animais , Bovinos , Análise Discriminante , Congelamento , Espectrometria de Massas , Carne/análise
9.
Antioxidants (Basel) ; 10(3)2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33809627

RESUMO

Oxidative stress is increasingly being recognized as a player in the pathogenesis of intestinal pathologies, and probiotics are becoming an attractive means of addressing it. The present study investigated the effects of dietary supplementation with Lactobacillus delbrueckii (LAB) on intestinal integrity and oxidative damage in lipopolysaccharide (LPS)-challenged piglets. A total of 36 crossbred weaned piglets (Duroc × Landrace × Large Yorkshire) were randomly divided into three groups: (1) non-challenged controls (CON), (2) LPS-challenged controls (LPS), and (3) 0.2% LAB (2.01 × 1010 CFU/g) + LPS treatment (LAB + LPS). On the 29th day of the experiment, the LPS and CON groups were injected intraperitoneally with LPS and saline at 100 ug/kg body weight, respectively. The results show that the LPS-induced elevation of the serum diamine oxidase (DAO) level and small intestinal crypt depth (CD) were reversed by the dietary addition of LAB, which also markedly increased the ileal expression of tight junction proteins (occludin, ZO-1, and claudin-1) in the LPS-challenged piglets. Furthermore, LAB supplementation normalized other LPS-induced changes, such as by decreasing malondialdehyde (MDA) in both the serum and intestinal mucosa and 8-hydroxy-2-deoxyguanosine (8-OHdG) in the jejunal mucosa, increasing glutathione reductase (GR) and glutathione peroxidase (GSH-Px) in both the serum and intestinal mucosa, and increasing glutathione (GSH) and superoxide dismutase (SOD) in the jejunal mucosa. LAB also activated Toll-like receptor (TLR)-Bruton's tyrosine kinase (Btk)-nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathways in the intestine, suggesting that it plays a vital role in the ameliorative antioxidant capacity of weaned piglets. In summary, LAB increased intestinal integrity by improving the intestinal structure and tight junctions while enhancing antioxidant functions via the activation of the TLR-Btk-Nrf2 signaling pathway.

10.
Talanta ; 226: 122134, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676688

RESUMO

Deep investigation, profiling of chemical diversity of constituent compounds and discovery of novel structures is a great challenge. A novel comprehensive and effective approach to mine trace unknown compounds combined with structure recognition in complex matrix is developed, in order to profiling potential Chlorogenic acids (CGAs) in Lonicera Flos (LFs): using multiple neutral loss/precursor ion (NL/PI) markers scans combined with high resolution mass spectrometry (HRMS). The workflow included (i) Fragmentation rules deduced by Q-orbitrap and selection of multiple NL/PI markers. (ii) Multiple NL/PI marker scans and grouping of peaks that had responses on two or more channels. (iii) Alignment of peaks in Full-MS scan and multiple NL/PI scans. (iv) The precursor ions list was introduced to mine novel CGAs according to simulated molecular formula. (v) Identification and structure recognition with the aid of HRMS. The procedure proved to be valid to screen and identify 51 CGAs from Lonicera Flos (LFs) with 16 categories, especially dihydroxyphenyl and glucoside for the first time. Its application could also be extended for global profiling of other complicated chemical systems, such as Chinese medicinal formulas.


Assuntos
Lonicera , Ácido Clorogênico , Cromatografia Líquida de Alta Pressão , Glucosídeos , Espectrometria de Massas
11.
Angew Chem Int Ed Engl ; 60(19): 10745-10755, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33555644

RESUMO

DNA-based molecular communications (DMC) are critical for regulating biological networks to maintain stable organismic functions. However, the complicated, time-consuming information transmission process involved in genome-coded DMC and the limited, vulnerable decoding activity generally lead to communication impairment or failure, in response to external stimuli. Herein, we present a conceptually innovative DMC strategy mediated by the DNA framework-based artificial DNA encoder. With the free-radical cascade as a proof-of-concept study, the artificial DNA encoder shows active sensing and real-time actuation, in situ and broad free radical-decoding efficacy, as well as robust resistance to environmental noise. It can also block undesirable short-to-medium-range communications between free radicals and inflammatory networks, leading to a synergistic anti-obesity effect. The artificial DNA encoder-based DMC may be generalized to other communication systems for a variety of applications.


Assuntos
DNA/química , Radicais Livres/química
12.
Histopathology ; 78(2): 300-309, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32767784

RESUMO

AIMS: Signet ring cell carcinoma (SRCC) is challenging to recognise on intra-operative frozen sections, with known high false-negative rates. The objective of this study was to investigate common factors contributing to discrepancies between intra-operative frozen diagnoses and those made upon review of permanent sections, and summarise our experiences gained and lessons learned on minimising errors on intra-operative frozen diagnoses of gastrointestinal SRCC. METHODS AND RESULTS: We retrospectively examined our pathology database from 25 May 2000 to 1 January 2018 and re-reviewed intra-operative frozen sections and permanent haematoxylin and eosin (H&E) slides for specimens confirmed with SRCC on permanent sections. This study includes 83 specimens taken from 50 patients, with an accuracy of 85.5%. Main common factors causing discordance or deferral in recognising SRCC between intra-operative frozen procedures and permanent sections include: (i) resemblance of clusters of SRCC cells with a myxoid background; (ii) disguise as normal or reactive cells (histiocytes, macrophages, large reactive lymphocytes, plasma cells or adipocytes) due to their relatively clear or depleted cytoplasmic mucin; and (iii) histological sampling errors, leading to misses of small foci of SRCC on frozen section slides. CONCLUSIONS: An accurate diagnosis of SRCC during intra-operative frozen consultations remains challenging. Based on our experiences and lessons, the most important strategies to reduce diagnostic errors are: (i) understanding the unusual histomorphological features of SRCC cells on frozen sections including, but not limited to, intracellular mucin depletion, absence of desmoplasia and no adjacent pre-cancer changes; and (ii) close attention to abrupt transition from normal architecture (e.g. glandular or submucosal loose connective tissue) to myxoid and/or inflammatory-like appearance, which potentially harbours SRCC.


Assuntos
Carcinoma de Células em Anel de Sinete , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células em Anel de Sinete/diagnóstico , Carcinoma de Células em Anel de Sinete/patologia , Carcinoma de Células em Anel de Sinete/cirurgia , Erros de Diagnóstico , Feminino , Secções Congeladas/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Encaminhamento e Consulta , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia
13.
Environ Pollut ; 274: 115800, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33234369

RESUMO

In this work, two deep subsurface wastewater infiltration systems (SWISs) were constructed and fed with domestic sewage (control system, S1) and mixed wastewater consisting of old landfill leachate and domestic sewage (experimental system, S2). S1 and S2 exhibited favorable removal efficiencies, with TP (98.8%, 98.7%), COD (87.6%, 86.9%), NH4+-N (99.8%, 99.9%) and TN (99.2%, 98.9%). Even when increasing the pollutant load in S2 by adding old landfill leachate, the almost complete removal performance could be maintained in terms of low effluent concentrations and even increased in terms of load removal capabilities, which included COD (19.4, 25.9 g∙m-2·d-1), NH4+-N (8.2, 19.9 g∙m-2·d-1), TN (8.9, 20.6 g∙m-2·d-1). To investigate the transformation of dissolved organic matter along depth, Three-Dimensional Excitation Emission Matrix fluorescence spectroscopy combined with Fluorescence Regional Integration analysis was applied. The results showed that PⅠ,n and PⅡ,n (the proportions of biodegradable fractions) increased gradually from 6.59% to 21.8% at S2_20 to 10.8% and 27.7% at S2_110, but PⅢ,n and PⅤ,n (the proportions of refractory organics) declined from 23.1% to 27.8% at S2_20 to 21.1% and 16.4% at S2_110, respectively. In addition, high-throughput sequencing technology was employed to observe the bacterial community at different depths, and the predicted functional potential of the bacterial community was analyzed by PICRUSt. The results showed that the genera Flavobacterium, Pseudomonas, Vogesella, Acinetobacter and Aquabacterium might be responsible for refractory organic degradation and that their products might serve as the carbon source for denitrifiers to achieve simultaneous nitrate and refractory organic removal. PICRUSt further demonstrated that there was a mutual response between refractory organic degradation and denitrification. Overall, the combined treatment of domestic sewage and old leachate in rural areas by SWIS is a promising approach to achieve comprehensive treatment.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Reatores Biológicos , Desnitrificação , Nitrogênio/análise , Esgotos
14.
Geriatr Gerontol Int ; 21(2): 203-208, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33325103

RESUMO

AIM: In this study, we seek to empirically understand the relationship between lifestyle habits and dementia risk. METHODS: Through an original online survey, we first confirm the significant difference in the dementia risk indicators between good and bad lifestyle habits. Then, using regression analysis to hold other factors equal, we examine the relationships between lifestyle habits and an aggregate dementia risk indicator. RESULTS: Through the t-test results, we find that the average scores of dementia risk for respondents avoiding good habits and preferring bad habits are significantly higher than those of the respondents favoring good habits and avoiding bad habits. Our empirical findings showed that Japanese-style dietary habits significantly correlate with a decreased dementia risk. An additional 1-point increase in eating habits will reduce dementia risk scores by 0.148 points, on average. Furthermore, we also confirm that walking (more than three times per week) and watching TV (almost every day) help prevent dementia. CONCLUSIONS: We conclude that maintaining a good lifestyle helps prevent dementia. In particular, good eating habits, both in terms of types of food and eating routines, are essential to avoid the development of dementia. Most of these lifestyle habits belong to the targets of the "Health Japan 21" project. Therefore, our findings might provide some convincing evidence for promoting the project, which will not only extend healthy life expectancy, but also reduce the increasing number of older adults with dementia. Geriatr Gerontol Int 2021; 21: 203-208.


Assuntos
Demência , Estilo de Vida , Idoso , Demência/epidemiologia , Demência/etiologia , Demência/prevenção & controle , Comportamento Alimentar , Hábitos , Humanos , Japão/epidemiologia , Fatores de Risco
15.
Animals (Basel) ; 11(1)2020 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-33375747

RESUMO

This study investigated the effects of excessive or restrictive energy on growth performance, meat quality, intramuscular fat (IMF) deposition, and related gene expression in finishing Ningxiang pigs. A total of 36 Ningxiang pigs (43.26 ± 3.21 kg) were randomly assigned to three treatments (6 pens of 2 piglets per treatment) and fed by one of three dietary treatments until the pigs of each treatment weighed approximately 75 kg equally. The three treatments were control diet (digestible energy, DE:13.02 MJ/kg, CON), excessive energy diet (DE 15.22 MJ/kg, EE), and restrictive energy diet (DE 10.84 MJ/kg, RE). Results showed that EE improved average daily gain (ADG) and feed conversion ratio (FCR) (p < 0.01), while nothing significantly changed by RE except FCR increasing (p < 0.01). EE increased the content of IMF and triglycerides (TG) (p < 0.05), L*24h and b*45min (p < 0.01), while decreasing cooking loss and meat tenderness in longissimus thoracis (LT) (p < 0.05). b*24h was significantly increased with the increase of energy level (p < 0.01). Meanwhile, EE increased the cross-sectional area (CSA) of muscle fiber and the mRNA expression of myosin heavy chain (MyHC) IIb, acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), and adipocyte fatty-acid binding protein (FABP4) (p < 0.05). In addition, throughout: A diet supplemented with excessive energy promoted IMF deposition by positively changing lipogenic potential while decreasing tenderness by increasing glycolytic muscle fibers, which together affected meat quality. In terms of growth performance and meat quality, the present study suggests that the low-energy diet is suitable for finishing Ningxiang pigs.

16.
Artigo em Inglês | MEDLINE | ID: mdl-33151806

RESUMO

An analytical method based on gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-MS/MS) was developed for the simultaneous determination of exogenous prohibited flavour compounds in coffee samples. In addition, gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) was developed to determine the origin of the founded prohibited flavour compound, N-methylpyrrole-2-carboxaldehyde (NMPCA). The good selectivity and sensitivity achieved in multiple reactions monitoring (MRM) mode allowed satisfactory confirmation and quantitation for the flavour compounds. The limits of detection (LODs) and limits of quantitation (LOQs) of these compounds were in the range of 0.0005-5.0 µg/kg and 0.002-16.0 µg/kg, respectively. The coffee samples were extracted with simultaneous distillation extraction (SDE) and NMPCA was analysed on a GC/C/IRMS system. The δ13C values of endogenous NMPCA in coffee beans were within a range of -35.0‰ to -31.1‰, whereas exogenous NMPCA was the range from -27.9‰ to -23.9‰. The validation results revealed that the GC-MS/MS method was sensitive and reliable, and the origin of NMPCA can be distinguished by GC/C/IRMS. Finally, this method was successfully applied to coffee samples analysis and NMPCA was found in coffee samples.


Assuntos
Aldeídos/análise , Café/química , Aromatizantes/análise , Pirróis/análise , Cromatografia Gasosa , Espectrometria de Massas em Tandem
17.
Talanta ; 219: 121282, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887172

RESUMO

Rapid analysis of trace analytes in complex biological samples is a great challenge for direct mass spectrometry, which suffers from low detection sensitivity. In this study, molecular imprinting technology was explored on the stainless steel sheet and integrated with the electrospray ionization method for direct sample analyses. The molecularly imprinted polymer-coated stainless steel sheet (MIPCS) was prepared and used as a solid-phase microextraction tip for rapid sampling of trace fluoroquinolone antibiotics in milk samples and then applied as an electrospray ionization tip to couple MS for sensitive detection. Our results shown that MIPCS could significantly enrich the trace fluoroquinolone antibiotics in milk samples. In our study, the extraction process of milk sample was completed within 30 min and the direct MS analysis was accomplished within 1 min. In addition, this proposed MIPCS-ESI-MS method showed a good linearity (R2>0.99) ranged from 1 to 1000 ng mL-1. The limits of detection (LODs) and limits of quantitation (LOQs) for the analytes range from 0.1 to 5 ng mL-1. The recoveries were in a range of 78.84%-103.04%. The relative standard deviation (RSD%) of inter-day and intra-day precision ranged from 7.00% to 10.4% and 4.46%-11.44% respectively. Overall, the proposed MIPCS-ESI-MS method could be feasibly used as a rapid and sensitive method for determination of trace analytes in complex food samples.


Assuntos
Impressão Molecular , Espectrometria de Massas por Ionização por Electrospray , Animais , Antibacterianos/análise , Fluoroquinolonas/análise , Leite/química , Polímeros Molecularmente Impressos , Aço Inoxidável
18.
Mikrochim Acta ; 187(9): 503, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32812169

RESUMO

A novel magnetic dual-template molecularly imprinted polymer (DMIP) was prepared with methyl-parathion and quinalphos as templates. For comparison, a series of single-template polymers with only methyl-parathion (MPMIP) or quinalphos (QPMIP) as template as well as a non-imprinted polymer (NIP) in the absence of the template, were synthesized using the same procedure of DMIP. The obtained MIPs were characterized by scanning electron microscopy(SEM), Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometer (VSM), and X-ray diffraction (XRD). The properties including kinetic effect, thermodynamic effect, selectivity, and reusability of MIPs were investigated . Only DMIP possessed high affinity and good recognition for all twelve OPPs including quinalphos, isazophos, chlorpyrifos-methyl, chlorpyrifos, methidathion, triazophos, profenofos, fenthion, fenitrothion, methyl-parathion, parathion, and paraoxon in comparison to MPMIP, QPMIP, or NIP. Moreover, DMIP was used as magnetic solid phase extraction (MSPE) sorbent for the pre-concentration of twelve OPPs in cabbage samples. The developed DMIP-MSPE-GC-MS method showed high sensitivity, low LODs (1.62-13.9 ng/g), fast adsorption equilibrium (10 min), and acceptable spiked recoveries (81.5-113.4%) with relative standard deviations (RSD) in the range 0.05-7.0% (n = 3). The calibration plots were linear in the range 10-800 ng/mL with coefficients of determination (R2) better 0.99 for all twelve compounds. These results suggest that the DMIP is applicable for rapid determination and high throughput analysis of multi-pesticide residues. Graphical abstract.


Assuntos
Metil Paration/isolamento & purificação , Polímeros Molecularmente Impressos/química , Compostos Organotiofosforados/isolamento & purificação , Praguicidas/isolamento & purificação , Adsorção , Brassica/química , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Fenômenos Magnéticos , Nanopartículas de Magnetita/química , Metil Paration/química , Compostos Organotiofosforados/química , Extração em Fase Sólida/métodos
19.
J Am Chem Soc ; 142(33): 14234-14239, 2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32677826

RESUMO

The requirement of special expensive instruments for quantitative information readout has significantly restricted sustainable development, from ideation to execution, of advanced artificial networks. Here we present a step toward a paradigm of evolutionary signaling networks that enable translating complex signaling information into easy-to-read temperature output. Combining DNA molecular engineering with basic optical mechanisms, a DNA/Hemin complex-derived versatile temperature-output transducer is established, which can be coupled with other functional modules to fabricate diverse portable DNA signaling networks by dynamic programming of DNA chemical reactions. Its versatility is successfully demonstrated by constructing self-amplified and logic-circuit-based DNA signaling networks to monitor trace and multibit nucleic acid interactions using a thermometer. This affordable yet powerful DNA signaling network design may portend an era of point-of-care signaling network methodology.


Assuntos
DNA/química , Hemina/química , Temperatura , Transdutores
20.
Oxid Med Cell Longev ; 2020: 6028606, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32104535

RESUMO

This study was conducted to evaluate the effect of dietary supplementation with Lactobacillus delbrueckii (LAB) on intestinal morphology, barrier function, immune response, and antioxidant capacity in weaned piglets challenged with lipopolysaccharide (LPS). A total of 36 two-line crossbred (Landrace × large Yorkshire) weaned piglets (28 days old) were divided into three groups: (1) nonchallenged control (CON); (2) LPS-challenged control (LPS); and (3) LAB+LPS treatment (0.2% LAB+LPS). Compared to the LPS piglets, the LAB+LPS piglets improved intestinal morphology, indicated by greater (P < 0.05) villus height in the duodenum and ileum; villus height : crypt depth ratio in the duodenum, jejunum, and ileum, as well as decreased (P < 0.05) crypt depth in the jejunum and ileum; and better intestinal barrier function, indicated by upregulated (P < 0.05) mRNA expression of tight junction proteins in the intestinal mucosa. Moreover, compared to the LPS piglets, LAB significantly decreased (P < 0.05) concentrations of TNF-α and IL-1ß in the small intestine and increased (P < 0.05) IL-10 levels in the jejunum and ileum. Additionally, LAB increased (P < 0.05) T-AOC activities of the colon, GSH concentrations of the jejunum, and mRNA expression of CAT and Cu/Zn-SOD, while reduced (P < 0.05) MDA concentrations in the jejunum and ileum in LPS-changed piglets. Collectively, our results indicate that supplementation of LAB improved intestinal integrity and immune response and alleviated intestinal oxidative damage in LPS-challenged piglets.


Assuntos
Antioxidantes/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Lactobacillus delbrueckii/fisiologia , Lipopolissacarídeos/farmacologia , Animais , Suplementos Nutricionais , Duodeno/efeitos dos fármacos , Duodeno/metabolismo , Duodeno/microbiologia , Feminino , Íleo/efeitos dos fármacos , Íleo/metabolismo , Íleo/microbiologia , Mucosa Intestinal/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Jejuno/metabolismo , Jejuno/microbiologia , Masculino , Suínos , Desmame
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...