Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Agric Food Chem ; 67(32): 8905-8918, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31380641

RESUMO

NAC TFs play crucial roles in response to abiotic stresses in plants. Here, ZmNAC071 was identified as a nuclear located transcriptional repressor. Overexpression of ZmNAC071 in Arabidopsis enhanced sensitivity of transgenic plants to ABA and osmotic stress. The expression levels of SODs, PODs, P5CSs, and AtMYB61 were inhibited by ZmNAC071, which results in reduced ROS scavenging and proline content, increased ROS level, and water loss. Besides, the expression levels of some ABA or abiotic stress-related genes, like ABIs, RD29A, DREBs, and LEAs were also significantly inhibited by ZmNAC071. Yeast one-hybrid assay demonstrated that ZmNAC071 specifically bound to the cis-acting elements containing CGT[G/A] core sequences in the promoter of stress-related genes, suggesting that ZmNAC071 may participate in the regulation of transcription of these genes through recognizing the core sequences CGT[G/A]. These results will facilitate further studies concerning the cis-elements and downstream genes targeted by ZmNAC071 in maize.


Assuntos
Arabidopsis/efeitos dos fármacos , Arabidopsis/fisiologia , Ácido Ascórbico/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/fisiologia , Fatores de Transcrição/genética , Zea mays/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação para Baixo/efeitos dos fármacos , Pressão Osmótica , Plantas Geneticamente Modificadas/genética , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Fatores de Transcrição/metabolismo
2.
Carbohydr Polym ; 222: 115008, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31320085

RESUMO

Amino cellulose (AC) is a cellulose derivative with biodegradability, biocompatibility, and excellent film-forming property, but AC film exhibits poor mechanical property and thermal stability. To improve the performance of AC film and further promote application, a novel composite film prepared from AC and bisphenol A-type-benzoxazine (BATB) are reported. In this paper, AC and BATB were firstly synthesized and characterized, then AC-BATB composite films were prepared with different weight ratios (AC/BATB) and temperatures by the synergistic interactions of chemical cross-linking and hydrogen bonds. Based on the results of tensile test and thermal analysis, BATB played a vital role in improving the mechanical and thermal properties of composite films, and the enhancement effect was more remarkable at elevated temperature. The maximum tensile strength and tensile modulus of composite films were 2.86 times and 7.26 times higher than that of AC control film, thus promoting the functional application of composite films.

3.
Dev Neurosci ; 41(1-2): 79-93, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31167194

RESUMO

Oligodendrocyte progenitor cells (OPCs) may have beneficial effects in cell replacement therapy of neurodegenerative disease owing to their unique capability to differentiate into myelinogenic oligodendrocytes (OLs) in response to extrinsic signals. Therefore, it is of significance to establish an effective differentiation methodology to generate highly pure OPCs and OLs from some easily accessible stem cell sources. To achieve this goal, in this study, we present a rapid and efficient protocol for oligodendroglial lineage differentiation from mouse neural stem cells (NSCs), rat NSCs, or mouse embryonic stem cell-derived neuroepithelial stem cells. In a defined culture medium containing Smoothened Agonist, basic fibroblast growth factor, and platelet-derived growth factor-AA, OPCs could be generated from the above stem cells over a time course of 4-6 days, achieving a cell purity as high as ∼90%. In particular, these derived OPCs showed high expandability and could further differentiate into myelin basic protein-positive OLs within 3 days or alternatively into glial fibrillary acidic protein-positive astrocytes within 7 days. Furthermore, transplantation of rodent NSC-derived OPCs into injured spinal cord indicated that it is a feasible strategy to treat spinal cord injury. Our results suggest a differentiation strategy for robust production of OPCs and OLs from rodent stem cells, which could provide an abundant OPC source for spinal cord injury.

4.
Nutrients ; 11(6)2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31207908

RESUMO

Obesity is associated with microvascular dysfunction. While low-fat diet improves cardiovascular risk, its contributions on microvascular function, independent of weight loss, is unknown. We tested the hypothesis that nitric oxide (NO)-dependent vasodilation in microvessels is improved by low-fat diets designed for weight loss (LFWL) compared to low-fat weight maintenance (LFWM) diet. Obese adults were randomly assigned to either a LFWL diet (n = 11) or LFWM diet (n = 10) for six weeks. Microvessels were obtained from gluteal subcutaneous fat biopsies before and after the intervention for vascular reactivity measurements to acetylcholine (Ach) and flow, with and without L-NAME or indomethacin. Vascular and serum NO and C-reactive protein (CRP) were also measured. LFWL diet increased flow-induced (FID) and ACh-induced dilation (AChID); an effect that was inhibited by L-NAME. Conversely, LFWM diet did not affect FID or AChID. Indomethacin improved FID and AChID in the baseline and this effect was minimized in response to both diets. Serum NO or CRP did not change in response to either diet. In conclusion, LFWL diet improves microvascular reactivity compared to LFWM diet and increased vascular NO contribution to the improved microvascular dilation. These data suggest that weight reduction on low fat diet is critical for microvascular health.

5.
Int J Biol Macromol ; 134: 122-130, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31071408

RESUMO

A facile and green route is introduced to fabricate antimicrobial composite films in this article from xylan (XL) and hydroxyethyl cellulose (HEC) with citric acid (CA) and polyethylene glycol 400 (PEG-400) as crosslinker and plasticizer, respectively. XL was obtained by precipitating wood hydrolysate (WH) produced during pulping process with ethanol. Antimicrobial activity was constructed by incorporating ß-cyclodextrin/sodium benzoate (ß-CD/NaBz) complex into the composite matrix. The interactions, including hydrogen bonds and covalent bonds, between the polymers were confirmed by FT-IR spectroscopy. Morphology and crystallinity of composite films at different curing time were investigated by AFM and XRD, respectively. The composite film cured for 40 min exhibits tensile strength up to 62.3 MPa and oxygen permeability (OP) as low as 1.0 cm3·µm m-2·d-1·kPa-1. Finally, the antimicrobial test against Staphylococcus aureus reveals superior antimicrobial activity of composite films with complex. In conclusion, the XL/HEC antimicrobial film has great potential in the field of sustainable food packing materials.

6.
Int J Biol Macromol ; 133: 514-521, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31004633

RESUMO

Eucalyptus wood was pretreated with an integrated process based on hydrothermal and alkaline pretreatments. The structural changes of hemicelluloses during the pretreatments and the components of the hydrolysates were comprehensively characterized. Sugar and spectral analyses indicated that the hemicelluloses remained in the residues obtained at hydrothermal pretreatment under low temperatures were mainly composed of a (1 → 4)-ß-D-Xylp backbone with 4-O-methyl-α-D-glucuronic acids attached at O-2 of the xylose together with various monosaccharides of rhamnose, arabinose, galactose, glucose, and mannose. The pretreatments resulted in serious degradation of hemicelluloses at high pretreatment temperatures. The distribution changes of the hemicelluloses in the cell walls during the integrated pretreatments were detected by Confocal Raman Microscopy, which revealed that the dissolution of hemicelluloses in different morphological regions was inhomogeneous, and the a large portion of hemicelluloses were removed from the secondary cell wall regions during the pretreatments.

7.
Int J Biol Macromol ; 132: 836-843, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30926494

RESUMO

Valorization of lignin by-product is an urgent issue in the context of biorefinery. Lignin is a natural anti-UV active ingredient with great potential applications. In this study, a natural broad-spectrum photo-protection agent was prepared using lignin from organic acid extraction process. The submicrometer particles were prepared by dialysis lignin recovered from the pretreatments with organic acid extraction processes (formic acid, formic acid/hydrogen peroxide, and acetic acid/hydrogen peroxide/HCl) and they served as active ingredients in sunblock formulation. The structures of the lignin submicrometer particles were characterized by multiple spectroscopies. The submicrometer particles from organic acid lignin showed high capacities to enhance the sun protection factor values of lotion by 2.80-3.53 at the dosage of 5%, and the lotions containing lignin submicrometer particles had good UV-blocking properties. In addition, the UVA/UVB values (i.e., the ratio of absorbance at UVA to that at UVB) were in the range of 0.69-0.72 for the organic acid lignin submicrometer particles, indicating that they exhibited superior properties. The results indicated that the lignin submicrometer-based lotions with excellent antioxidant and UV protection capacities offered a natural source for sunblock cosmetics.

8.
Bioresour Technol ; 280: 489-492, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30808592

RESUMO

In this study, an organosolv process based on tetrahydro-2-furanmethanol/acid aqueous solution was developed to release lignin and hemicelluloses from eucalyptus for the enhancement of enzymatic hydrolysis. The pretreatment with 80% THFA aqueous solution containing 1% HCl at a solid to liquid ratio of 1:10 was conducted at 120-180 °C for 30 min. Under the serious conditions, the cellulose-rich residue had a high proportion of cellulose up to 87.31%. The enzymatic hydrolysis rate of the cellulose-rich fraction was 94.18%, which was enhanced by 7.3-fold as compared to that of the raw material without pretreatment. The fractionation process resulted in a high delignification rate of 93.95%. The lignin produced with medium molecular weight (2190 g/mol) and high purity (contaminated sugar content 0.6%) was a good substrate for further application as chemicals.


Assuntos
Celulose/metabolismo , Eucalyptus/metabolismo , Lignina/metabolismo , Metanol/química , Eucalyptus/química , Hidrólise , Peso Molecular
9.
PLoS One ; 13(12): e0208110, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30540809

RESUMO

The propensity for differentiation varies substantially across human pluripotent stem cell (hPSC) lines, greatly restricting the use of hPSCs for cell replacement therapy or disease modeling. Here, we investigate the underlying mechanisms and demonstrate that activation of the retinoblastoma (Rb) pathway in a transient manner is important for differentiation. In prior work, we demonstrated that pre-treating hPSCs with dimethylsulfoxide (DMSO) before directed differentiation enhanced differentiation potential across all three germ layers. Here, we show that exposure to DMSO improves the efficiency of hPSC differentiation through Rb and by repressing downstream E2F-target genes. While transient inactivation of the Rb family members (including Rb, p107, and p130) suppresses DMSO's capacity to enhance differentiation across all germ layers, transient expression of a constitutively active (non-phosphorylatable) form of Rb increases the differentiation efficiency similar to DMSO. Inhibition of downstream targets of Rb, such as E2F signaling, also promotes differentiation of hPSCs. More generally, we demonstrate that the duration of Rb activation plays an important role in regulating differentiation capacity.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Dimetil Sulfóxido/farmacologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Proteína do Retinoblastoma/metabolismo , Transdução de Sinais/efeitos dos fármacos , Aminopiridinas/farmacologia , Técnicas de Cultura de Células , Diferenciação Celular/genética , Linhagem Celular , Fatores de Transcrição E2F/antagonistas & inibidores , Fatores de Transcrição E2F/metabolismo , Técnicas de Silenciamento de Genes , Camadas Germinativas/citologia , Camadas Germinativas/efeitos dos fármacos , Camadas Germinativas/fisiologia , Humanos , Hidroxiquinolinas/farmacologia , Células-Tronco Pluripotentes/fisiologia , Proteína do Retinoblastoma/genética , Proteína p107 Retinoblastoma-Like/genética , Proteína p107 Retinoblastoma-Like/metabolismo , Proteína p130 Retinoblastoma-Like/genética , Proteína p130 Retinoblastoma-Like/metabolismo , Transdução de Sinais/genética , Fatores de Tempo
10.
Materials (Basel) ; 11(11)2018 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-30428577

RESUMO

Wood auto-hydrolysates (WAH) are obtained in the pulping process by the hydrothermal extraction, which contains lots of hemicelluloses and slight lignin. WAH and chitosan (CS) were introduced into this study to construct WAH-based films by the casting method. The FT-IR results revealed the crosslinking interaction between WAH and CS due to the Millard reaction. The morphology, transmittance, thermal properties and mechanical properties of composite WAH/CS films were investigated. As the results showed, the tensile strength, light transmittances and thermal stability of the WAH-based composite films increased with the increment of WAH/CS content ratio. In addition, the results of oxygen transfer rate (OTR) and water vapor permeability (WVP) suggested that the OTR and WVP values of the films decreased due to the addition of CS. The maximum value of tensile strengths of the composite films achieved 71.2 MPa and the OTR of the films was low as 0.16 cm³·µm·m-2·24 h-1·kPa-1, these properties are better than those of other hemicelluloses composite films. These results suggested that the barrier composite films based on WAH and CS will become attractive in the food packaging application for great mechanical properties, good transmittance and low oxygen transfer rate.

11.
J Nematol ; 50(1): 3-8, 2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-30335907

RESUMO

A variety of natural substances including both volatile organic compounds and water-soluble compounds play a significant role in the chemotactic behaviors of the model nematode Caenorhabditis elegans. We observed chemotactic behaviors of C. elegans with respect to response to attractants produced by nematode parasitic fungus Stropharia rugosoannulata, which were partially induced by specific amino acids. The results of gas chromatography-mass spectrometer analysis suggested that 1-octen-3-ol was produced and benzaldehyde concentrations increased when L-phenylalanine was added to water agar plate. Similarly, the addition of L-tryptophan to the medium induced the production of benzaldehyde, 1-octen-3-ol and indole. The presence of L-phenylalanine and L-tryptophan increased the attraction of C. elegans to S. rugosoannulata. With attraction increased, nematode mortality increased more than 6 times higher.

12.
Bioresour Technol ; 270: 216-222, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30218938

RESUMO

Subcritical hydrothermal liquefaction of poplar was performed at 220-280 °C, and the liquid phase produced was extracted by ethyl acetate to obtain light oil (LO), which contained LO1 (water-soluble) and LO2 (ethyl acetate-soluble). The residue was further extracted with acetone to produce heavy oil (HO) and solid residue (SR). The highest bio-oil yield of 19.88% was obtained at 260 °C. The HO produced at 260 °C had the highest content of C (69.13%) and the higher heating value was 27.97 MJ/kg. The O/C and H/C ratios of LO were higher than those of HO due to less aromatics in LO. Oxidative inhibition rates of bio-oils, measured in DPPH-ethanol solution at a concentration of 0.1 mg/mL, reached 60.76% for LO1 while 90.29% and 90.85% for LO2 and HO, respectively. The bio-oil with good antioxidant activity can be utilized as an additive in bio-diesel to improve oxidation stability.

13.
J Agric Food Chem ; 66(35): 9199-9208, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-30102859

RESUMO

To study the differences in chemical composition analysis and spatial distribution of young Neosinocalamus affinis bamboo, we used the methods of standard of National Renewable Energy Laboratory and confocal Raman microscopy, respectively. It was found that the acid-soluble lignin and acid-insoluble lignin content showed an inverse relationship with the increasing bamboo age. Raman analysis revealed that Raman signal intensity of lignin in both the secondary cell wall and the compound middle lamella regions showed a similar increase trend with growth of bamboo. In addition, eight hemicellulosic fractions were obtained by successively treating holocellulose of the 2-, 4-, 8-, and 12-month-old Neosinocalamus affinis bamboo culms with DMSO and alkaline solution. The ratio of arabinose to xylose of hemicelluloses was increased with the growth of bamboo. FT-IR and NMR analyses revealed that DMSO-soluble hemicelluloses of young bamboo culms are mainly composed of highly substituted xylans and ß-d-glucans.


Assuntos
Bambusa/química , Extratos Vegetais/química , Bambusa/crescimento & desenvolvimento , Parede Celular/química , Lignina/química , Lignina/isolamento & purificação , Espectroscopia de Ressonância Magnética , Extratos Vegetais/isolamento & purificação , Brotos de Planta/química , Brotos de Planta/crescimento & desenvolvimento , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Artigo em Inglês | MEDLINE | ID: mdl-30103405

RESUMO

Although the acceleration of urbanization brings social and economic development, it also produces various problems. Accurate evaluation of sustainable urbanization performance can help local governments summarize experiences and solve problems. Sustainable urban development should focus not only on modern construction, but also on original natural ecosystems and traditional cultural protection. This paper develops a holistic framework based on an "origin" and "modernization" perspectives and uses the multilevel extension method and the Analytic Hierarchy Process (AHP) method for accurately evaluating sustainable urbanization performance. A case study of Chongqing City in China demonstrates the process of using the holistic framework and evaluation method. The empirical results from this study indicate that Chongqing has a medium level of sustainable urbanization. The city is considered as a medium level in "origin" performance and the "modernization" performance is good, while uncoordinated. The case study reveals that the proposed framework and the method are effective theoretical bases for policy-makers and practitioners to understand the performance of urban sustainability and for promoting urbanization toward better sustainability. Beyond the application case, the holistic framework and method can be applied to other cities.

15.
Sheng Li Xue Bao ; 70(4): 343-353, 2018 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-30112559

RESUMO

Myocardial fibrosis (MF) is an important pathological process of cardiac remodeling in patients with heart failure; however its etiology has not been clear. It has been known that the angiotensin II type 1 receptor autoantibody (AT1-AA) is present in patients with heart failure, but it is unclear whether this antibody directly causes MF. In this study, we investigated the role of AT1-AA in MF and its effects on cardiac fibroblasts (CFs). The AT1-AA positive rat model was established by active immunization method, and the measurement of indexes were made in the 8th week after active immunity. The results of heart echocardiography showed that the cardiac systolic and diastolic functions of AT1-AA positive rats were impaired with reduced left ventricular wall thickness and enlarged heart chambers. HE staining results showed that the myocardial fibers were disorganized and ruptured, and Masson staining revealed that the area of collagen fibers around the myocardium and coronary arteries was significantly increased in AT1-AA positive group compared with that of the control group (P < 0.05). Moreover, primary CFs isolated from neonatal rats were cultured and treated with AT1-AA for 48 h. CCK-8 and immunofluorescence staining results showed that AT1-AA enhanced proliferation rate of CFs (P < 0.001), and Western blot results showed that AT1-AA significantly increased expressions of collagen I (Col I), Col III, matrix metalloproteinase-2 (MMP-2) and MMP-9 in CFs (all P < 0.05). Taken together, these results suggest that AT1-AA may induce MF and cardiac dysfunction via activating CFs.

16.
Am J Physiol Cell Physiol ; 315(4): C587-C597, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30044661

RESUMO

Osteoblasts secrete collagen and isolate bone matrix from extracellular space. In the matrix, alkaline phosphatase generates phosphate that combines with calcium to form mineral, liberating 8 H+ per 10 Ca+2 deposited. However, pH-dependent hydroxyapatite deposition on bone collagen had not been shown. We studied the dependency of hydroxyapatite deposition on type I collagen on pH and phosphate by surface plasmon resonance in 0-5 mM phosphate at pH 6.8-7.4. Mineral deposition saturated at <1 mM Ca2+ but was sensitive to phosphate. Mineral deposition was reversible, consistent with amorphous precipitation; stable deposition requiring EDTA removal appeared with time. At pH 6.8, little hydroxyapatite deposited on collagen; mineral accumulation increased 10-fold at pH 7.4. Previously, we showed high expression Na+/H+ exchanger (NHE) and ClC transporters in osteoblasts. We hypothesized that, in combination, these move protons across osteoblasts to the general extracellular space. We made osteoblast membrane vesicles by nitrogen cavitation and used acridine orange quenching to characterize proton transport. We found H+ transport dependent on gradients of chloride or sodium, consistent with apical osteoblast ClC family Cl-,H+ antiporters and basolateral osteoblast NHE family Na+/H+ exchangers. Little, if any, active H+ transport, supported by ATP, occurred. Major transporters include cariporide-sensitive NHE1 in basolateral membranes and ClC3 and ClC5 in apical osteoblast membranes. The mineralization inhibitor levamisole reduced bone formation and expression of alkaline phosphatase, NHE1, and ClC5. We conclude that mineral deposition in bone collagen is pH-dependent, in keeping with H+ removal by Cl-,H+ antiporters and Na+/H+-exchangers. Periodic orientation hydroxyapatite is organized on type I collagen-coiled coils.

17.
Artigo em Inglês | MEDLINE | ID: mdl-29958438

RESUMO

With the rapid development of urbanization in China, a vast number of subway projects are under construction and planned in many cities. However, the complexities of the environment in subway construction inherently bring about many uncertainties and risk factors. Understanding the inherent properties of the critical success factors (CSFs) will contribute significantly to the subway construction. From this perspective, this paper aims to identify the CSFs for safety management in subway construction. This study screened preliminary CSFs through a literature review and in-depth interviews with experts in China. Based on the data gathered and subsequently analyzed from the questionnaire surveys, a final total of 24 CSFs were identified. Then, interpretative structural modeling was employed to ascertain the interrelations among them. The result showed that the factors concerning the engineering survey and design not only occupy relatively higher scores in the questionnaire survey but also contribute significantly latent impacts on other factors. In addition, the creation of a reasonable schedule and the investment of the safety measures were also found to have a fundamental impact on the safety management of subway construction. This research guided the safety managers in determining the most important safety factors they must face and provided them valuable information that could promote safety performance and decrease the number of accidents over the course of subway construction.

18.
Carbohydr Polym ; 195: 303-310, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29804981

RESUMO

Chemical structure determination of xylo-oligosaccharides obtained by common production pathway is difficult, since the products mixture must be separated and purified into individual chemicals. In the present study, gel permeation chromatography was used to efficiently separate and purify the xylo-oligosaccharides produced by biomass autohydrolysis for the chemical structural evaluation. Results showed that the separation obtained high purity (85.2-94.5%) xylo-oligosaccharides with individual component. The separated samples were further characterized by ESI-MS and NMR, which revealed that the samples were non-substituted xylobiose and acetylated xylo-oligosaccharides with degree of polymerization from 3 to 6. The combined 1H, 13C and two-dimensional proton-detected heteronuclear single quantum (2D HSQC) NMR spectra results suggested that acetyl groups only attached to the internal units of xylo-oligosaccharides after autohydrolysis, and no acetylated non-reducing ends were detected.

19.
Sci Rep ; 8(1): 5502, 2018 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-29615755

RESUMO

Methamphetamine (MA) abuse has been rising rapidly over the past decade, however, its impact in spatial cognitive function remains unknown. To understand its effect on visuospatial ability and spatial orientation ability, 40 MA users and 40 non-MA users conducted the Simple Reaction Task (Task 1), the Spatial Orientation Task (Task 2), and the Mental Rotation Task (Task 3), respectively. There was no significant difference in either accuracy or reaction time (RT) between 2 groups in Task 1. During Task 2, in comparison with non-MA users, MA users performed poorer on RT, but not in accuracy for foot and hand stimuli. In addition, both non-MA and MA users responded much more quickly to upward stimuli than downward stimuli on vertical surface, however, only non-MA users exhibited leftward visual field advantage in horizontal orientation processing. As for Task 3, MA users exhibited poorer performance and more errors than their healthy counterparts. For each group, linear relationship was revealed between RT and orientation angle, whereas MA abuse led to longer intercept for all stimuli involved. Our findings suggested that MA abuse may lead to a general deficit in the visuospatial ability and the spatial orientation ability with more serious impact in the former.

20.
Artigo em Inglês | MEDLINE | ID: mdl-29451853

RESUMO

Mycotoxins are potential food pollutants produced by fungi. Among them, aflatoxins (AFs) are the most toxic. Therefore, AFs were selected as models, and a sensitive, simple and green graphene oxide (GO)-based stir bar sorptive extraction (SBSE) method was developed for extraction and determination of AFs with high performance liquid chromatography-laser-induced fluorescence detector (HPLC-LIF). This method improved the sensitivity of AFs detection and solved the deposition difficulty of the direct use of GO as adsorbent. Several parameters including a spiked amount of NaCl, stirring rate, extraction time and desorption time were investigated. Under optimal conditions, the quantitative method had low limits of detection of 2.4-8.0 pg/mL, which were better than some reported AFs analytical methods. The developed method has been applied to soy milk samples with good recoveries ranging from 80.5 to 102.3%. The prepared GO-based SBSE can be used as a sensitive screening technique for detecting AFs in soy milk.


Assuntos
Aflatoxinas/isolamento & purificação , Fluorescência , Grafite/química , Lasers , Óxidos/química , Extração em Fase Sólida , Leite de Soja/química , Adsorção , Aflatoxinas/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Fluorescência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA