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1.
J Environ Manage ; 340: 117996, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37087889

RESUMO

Potassium ferrate (PF) pretreatment in anaerobic sludge and its potential influence mechanisms have received widely attention. This study investigated the coupling effect of PF loading on steel slag (SS) on excess sludge anaerobic fermentation. Results showed that SS loading increase the treatment performance of PF on short chain volatile fatty acids (SCFAs) production from anaerobic fermented sludge. It was showed that the modified PF loaded SS (MPF-SS) promoted the dissolution and release of organic substrates from intracellular to extracellular. Further exploration showed the promotion of PF and MPF-SS exposure to acid production microorganisms was much more than that to acid consumption microorganisms. MPF-SS addition can also effectively reinforce the carbohydrate transport, amino acid metabolism and the key enhanced genes associated with fatty acid biosynthesis pathways. This study fills the knowledge gap about modified PF on sludge treatment and also expands a new perspective for its application for sludge resource recovery.


Assuntos
Esgotos , Aço , Fermentação , Esgotos/química , Anaerobiose , Ácidos Graxos Voláteis , Concentração de Íons de Hidrogênio
2.
J Environ Manage ; 343: 118203, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37235988

RESUMO

Quaternary ammonium compounds (QACs) was frequently detected in wastewater treatment plants and leads to potential toxicity to the related biological processes. In this study, the effect of benzalkonium bromide (BK) on anaerobic sludge fermentation process for short chain fatty acid (SCFAs) production was investigated. Batch experiments indicated that BK exposure significantly enhanced the SCFAs production from anaerobic fermentation sludge and the maximum concentration of total SCFAs increased from 474.40 ± 12.35 mg/L to 916.42 ± 20.35 mg/L with BK increasing from 0 to 8.69 mg/g VSS. Mechanism exploration exhibited that the presence of BK enhanced much more bioavailable organic matters release, little affected on hydrolysis, acidification, but seriously inhibited methanogenesis. Microbial community investigation revealed that BK exposure importantly enhanced the relative abundances of hydrolytic-acidifying bacteria and also improved the metabolic pathways and functional genes for sludge lysis. This work further supplement the information for environmental toxicity of emerging pollutants.


Assuntos
Compostos de Benzalcônio , Esgotos , Fermentação , Anaerobiose , Brometos , Ácidos Graxos Voláteis/metabolismo , Concentração de Íons de Hidrogênio
3.
Crit Rev Food Sci Nutr ; : 1-25, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35880423

RESUMO

Mycotoxins are toxic secondary metabolites generated from toxigenic fungi in the contaminated food and agro-food, which have been regarded as a serious threat to the food safety and human health. Therefore, the control of mycotoxins and toxigenic fungi contamination is of great significance and has attracted the increasing attention of researchers. As we know, nano-semiconductors have many unique properties such as large surface area, structural stability, good biocompatibility, excellent photoelectrical properties, and low cost, which have been developed and applied in many research fields. Recently, nano-semiconductors have also been promisingly applied in mitigating or controlling mycotoxins and toxigenic fungi contaminations in food and agro-food. In this review, the type, occurrence, and toxicity of main mycotoxins in food and agro-food were introduced. Then, a variety of strategies to mitigate the mycotoxin contamination based on nano-semiconductors involving mycotoxins detection, inhibition of toxigenic fungi, and mycotoxins degradation were summarized. Finally, the outlook, opportunities, and challenges have prospected in the future for the mitigation of mycotoxins and toxigenic fungi based on nano-semiconductors.

4.
Plant Cell Rep ; 41(12): 2379-2391, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36208306

RESUMO

KEY MESSAGE: Within a QTL, the genetic recombination and interactions among five and two functional variations at MdbHLH25 and MdWDR5A caused much complicated phenotype segregation in apple FFR and FCR. The storability of climacteric fruit like apple is a quantitative trait. We previously identified 62 quantitative trait loci (QTLs) associating flesh firmness retainability (FFR) and flesh crispness retainability (FCR), but only a few functional genetic variations were identified and validated. The genetic variation network controlling fruit storability is far to be understood and diagnostic markers are needed for molecular breeding. We previously identified overlapped QTLs F16.1/H16.2 for FFR and FCR using an F1 population derived from 'Zisai Pearl' × 'Red Fuji'. In this study, five and two single-nucleotide polymorphisms (SNPs) were identified on the candidate genes MdbHLH25 and MdWDR5A within the QTL region. The SNP1 A allele at MdbHLH25 promoter reduced the expression and SNP2 T allele and/or SNP4/5 GT alleles at the exons attenuated the function of MdbHLH25 by downregulating the expression of the target genes MdACS1, which in turn led to a reduction in ethylene production and maintenance of higher flesh crispness. The SNPs did not alter the protein-protein interaction between MdbHLH25 and MdWDR5A. The joint effect of SNP genotype combinations by the SNPs on MdbHLH25 (SNP1, SNP2, and SNP4) and MdWDR5A (SNPi and SNPii) led to a much broad spectrum of phenotypic segregation in FFR and FCR. Together, the dissection of these genetic variations contributes to understanding the complicated effects of a QTL and provides good potential for marker development in molecular breeding.


Assuntos
Malus , Locos de Características Quantitativas , Locos de Características Quantitativas/genética , Malus/genética , Mapeamento Cromossômico , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
5.
Int J Mol Sci ; 23(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36499548

RESUMO

Construction of the tunable oxygen vacancies (OVs) is widely utilized to accelerate molecular oxygen activation for boosting photocatalytic performance. Herein, the in-situ introduction of OVs on Bi2MoO6 was accomplished using a calcination treatment in an H2/Ar atmosphere. The introduced OVs can not only facilitate carrier separation, but also strengthen the exciton effect, which accelerates singlet oxygen generation through the energy transfer process. Superior carrier separation and abundant singlet oxygen played a crucial role in favoring photocatalytic NaPCP degradation. The optimal BMO-001-300 sample exhibited the fastest NaPCP degradation rate of 0.033 min-1, about 3.8 times higher than that of the pristine Bi2MoO6. NaPCP was effectively degraded and mineralized mainly through dechlorination, dehydroxylation and benzene ring opening. The present work will shed light on the construction and roles of OVs in semiconductor-based photocatalysis and provide a novel insight into ROS-mediated photocatalytic degradation.


Assuntos
Pentaclorofenol , Oxigênio Singlete , Oxigênio , Sódio
6.
Entropy (Basel) ; 24(2)2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35205589

RESUMO

As computational fluid dynamics (CFD) advances, entropy generation minimization based on CFD becomes attractive for optimizing complex heat-transfer systems. This optimization depends on the accuracy of CFD results, such that accurate turbulence models, such as elliptic relaxation or elliptic blending turbulence models, become important. The performance of a previously developed elliptic blending turbulence model (the SST k-ω-φ-α model) to predict the rate of entropy generation in the fully developed turbulent circular tube flow with constant heat flux was studied to provide some guidelines for using this class of turbulence model to calculate entropy generation in complex systems. The flow and temperature fields were simulated by using a CFD package, and then the rate of entropy generation was calculated in post-processing. The analytical correlations and results of two popular turbulence models (the realizable k-ε and the shear stress transport (SST) k-ω models) were used as references to demonstrate the accuracy of the SST k-ω-φ-α model. The findings indicate that the turbulent Prandtl number (Prt) influences the entropy generation rate due to heat-transfer irreversibility. Prt = 0.85 produces the best results for the SST k-ω-φ-α model. For the realizable k-ε and SST k-ω models, Prt = 0.85 and Prt = 0.92 produce the best results, respectively. For the realizable k-ε and the SST k-ω models, the two methods used to predict the rate of entropy generation due to friction irreversibility produce the same results. However, for the SST k-ω-φ-α model, the rates of entropy generation due to friction irreversibility predicted by the two methods are different. The difference at a Reynolds number of 100,000 is about 14%. The method that incorporates the effective turbulent viscosity should be used to predict the rate of entropy generation due to friction irreversibility for the SST k-ω-φ-α model. Furthermore, when the temperature in the flow field changes dramatically, the temperature-dependent fluid properties must be considered.

7.
Appl Opt ; 57(11): 2804-2808, 2018 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-29714282

RESUMO

High-power photoconductive semiconductor switching devices were fabricated from a high-purity, semi-insulating 4H-SiC wafer. A highly n-doped GaN subcontact layer was inserted between the contact metal and the high-resistivity SiC wafer. The minimum ON-state resistance of the device was less than 1 ohm when the energy of a 355 nm laser was 10.5 mJ with a bias voltage of 6 kV. The maximum device lifetime is 3151 pulses, after which the device completely fails. The failure mechanisms are determined using several analysis methods. Under a strong electric field, the failure mechanism differs for the two electrodes. Near the edge of the anode electrode, the switch is damaged due to the thermal stress caused by impact ionization. At the edge of the cathode electrode, the electrode erosion is the main reason for the failure to operate for long periods of time. These two different damage mechanisms are both important factors influencing the device performance. The electron avalanche breakdown at the edge of the anode electrode causes the formation of cracks between the electrodes, which is the root cause of the switch failure.

8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(9): 2516-20, 2015 Sep.
Artigo em Zh | MEDLINE | ID: mdl-26669158

RESUMO

Soil available phosphorus (P) and available potassium (K) don't possess direct spectral response in the near infrared (NIR) region. They are predictable because of their correlation with spectrally active constituents (organic matter, carbonates, clays, water, etc.). Such correlation may of course differ between the soil sample sets. Therefore, the NIR calibration models with fixed structure are difficult to achieve good prediction performances for soil P and K. In this work, the method of recursive partial least squares (RPLS), which is able to update the model coefficients recursively during the prediction process, has been applied to improve the predictive abilities of calibration models. This work compared the performance of partial least squares regression (PLS), locally weighted PLS (LW-PLS), moving window LW-PLS (LW-PLS2) and RPLS for the measurement of soil P and K. The entire data set of 194 soil samples was split into calibration set and prediction set based on soil types. The calibration set was composed of 120 Anthrosols samples, while the prediction set included 29 Ferralsols samples, 23 Anthrosols samples and 22 Primarosols samples. The best prediction results were obtained by the RPLS model. The coefficient of determination (R2) and residual prediction deviation (RPD) were respectively 0.61, 0.76 and 1.60, 2.05 for soil P and K. The results indicate that RPLS is able to learn the information from the latest modeling sample by recursively updating the model coefficients. The proposed method RPLS has the advantages of wider applicability and better performance for NIR prediction of soil P and K compared with other methods in this work.

9.
BMC Musculoskelet Disord ; 15: 314, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25257938

RESUMO

BACKGROUND: Metal hypersensitivity, mostly documented in prosthesis implantation, is a rare complication after arthroplasty. Such cases become rarer and more difficult to diagnose when it comes to lumbar surgery. CASE PRESENTATION: We present the case of a 52-year-old female patient with reoccured low back pain and sciatica after posterior lumbar decompression and fusion (PLDF) for her lumbar disc herniation. The initial clinical and radiological examinations showed no pathologies. Further imaging and histopathological studies in later period revealed an aseptic loosening of the hardware and an aseptic inflammatory response which was diagnosed to be metal hypersensitivity. To our knowledge, few allergic cases in the matter of spinal fusion were reported so far. CONCLUSIONS: Metal hypersensitivity after spinal fusion should be considered in patients with representation of postoperative back pain. And elaborate history taking would conduce a lot to it's diagnose.


Assuntos
Dermatite de Contato/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Metais/efeitos adversos , Fusão Vertebral/efeitos adversos , Dermatite de Contato/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Radiografia , Fusão Vertebral/instrumentação , Resultado do Tratamento
10.
BMC Musculoskelet Disord ; 15: 40, 2014 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-24517217

RESUMO

BACKGROUND: Currently, Posterior Short Segment Pedicle Screw Fixation is a popular procedure for treating unstable thoracolumbar/lumbar burst fracture. But progressive kyphosis and a high rate of hardware failure because of lack of the anterior column support remains a concern. The efficacy of different methods remains debatable and each technique has its advantages and disadvantages. METHODS: A consecutive series of 20 patients with isolated thoracolumbar/lumbar burst fractures were treated by posterior short segment pedicle screw fixation and transforaminal thoracolumbar/lumbar interbody fusion (TLIF) between January 2005 and December 2007. All patients were followed up for a minimum of 2 years. Demographic data, neurologic status, anterior vertebral body heights, segmental Cobb angle and treatment-related complications were evaluated. RESULTS: The mean operative time was 167 minutes (range, 150-220). Blood loss was 450 ~ 1200 ml, an average of 820 ml. All patients recovered with solid fusion of the intervertebral bone graft, without main complications like misplacement of the pedicle screw, nerve or vessel lesion or hard ware failure. The post-operative radiographs demonstrated a good fracture reduction and it was well maintained until the bone graft fusion. Neurological recovery of one to three Frankel grade was seen in 14 patients with partial neurological deficit, three grades of improvement was seen in one patient, two grades of improvement was observed in 6 patients and one grade of improvement was found in 6 patients. All the 6 patients with no paraplegia on admission remained neurological intact, and in one patient with Frankel D on admission no improvement was observed. CONCLUSION: Posterior short-segment pedicle fixation in conjunction with TLIF seems to be a feasible option in the management of selected thoracolumbar/lumbar burst fractures, thereby addressing all the three columns through a single approach with less trauma and good results.


Assuntos
Parafusos Ósseos , Fixação de Fratura/instrumentação , Vértebras Lombares/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Fusão Vertebral/instrumentação , Vértebras Torácicas/cirurgia , Adolescente , Adulto , Perda Sanguínea Cirúrgica , Transplante Ósseo , Feminino , Fixação de Fratura/efeitos adversos , Consolidação da Fratura , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/lesões , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Osseointegração , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Desenho de Prótese , Radiografia , Recuperação de Função Fisiológica , Fraturas da Coluna Vertebral/diagnóstico , Fraturas da Coluna Vertebral/fisiopatologia , Fusão Vertebral/efeitos adversos , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/lesões , Vértebras Torácicas/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(11): 3015-9, 2014 Nov.
Artigo em Zh | MEDLINE | ID: mdl-25752049

RESUMO

Ultraviolet/visible (UV/Vis) spectroscopy was investigated for the rapid determination of chemical oxygen demand (COD) which was an indicator to measure the concentration of organic matter in aquaculture water. A total number of 135 collected turtle breeding water samples were scanned for UV/Vis spectrum, uninformative variable elimination (UVE) and successive projections algorithm (SPA) were combined as a mixed variable selection method to perform characteristic wavelength selection from the full wavelength spectrum, 7 characteristic wavelengths were selected from full 201 UV/Vis spectral variables, which were just 3.48% number of the full range spectrum, and the calibration time and complexity of the modeling were greatly reduced. The predicted results which were obtained by using least squares-support vector machine (LS-SVM) calibration showed that the characteristic wavelengths achieved better results (0.89 for correlation coefficient (r), 15.46 mg x L(-1) for root mean square error of prediction (RMSEP)) than full wavelengths did (0.88 for r and 15.71 mg x L(-1) for RMSEP). The comprehensive results revealed that the UV/Vis characteristic wavelengths which were obtained by UVE-SPA variable selection method, combined with LS-SVM calibration could apply to the rapid and accurate determination of COD in aquaculture water. Moreover, this study laid the foundation for further implementation of online analysis of aquaculture water and rapid determination of other water quality parameters.


Assuntos
Aquicultura , Compostos Orgânicos/análise , Espectroscopia de Luz Próxima ao Infravermelho , Água/análise , Algoritmos , Calibragem , Análise dos Mínimos Quadrados , Máquina de Vetores de Suporte
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(8): 2070-5, 2014 Aug.
Artigo em Zh | MEDLINE | ID: mdl-25474936

RESUMO

In the present work, recursive variable selection methods (updating both the model coefficients and effective variables during the prediction process) were applied to maintain the predictive abilities of calibration models. This work compared the performances of partial least squares (PLS), recursive PLS (RPLS) and three recursive variable selection methods, namely vari- able importance in the projection combined with RPLS (VIP-RPLS), VIP-PLS, and uninformative variable elimination combined with PLS (UVE-PLS) for the measurement of soil total nitrogen (TN) and organic matter (OM) using Vis-NIR spectroscopy. The dataset consisted of 195 soil samples collected from eight towns in Wencheng County, Zhejiang Province, China. The entire data set was split randomly into calibration set and prediction set. The calibration set was composed of 120 samples, while the prediction set included 75 samples. The best prediction results were obtained by the VIP-RPLS model. The coefficient of determination (R2) and residual prediction deviation (RPD) were respectively 0.85, 0.86 and 2.6%, 2.7% for soil TN and OM. The results indicate that VIP-RPLS is able to capture the effective information from the latest modeling sample by recursively updating the effective variables. The proposed method VIP-RPLS has the advantages of better performance for Vis-NIR prediction of soil N and OM compared with other methods in this work.


Assuntos
Nitrogênio/análise , Compostos Orgânicos/análise , Solo/química , Espectroscopia de Luz Próxima ao Infravermelho , China , Análise dos Mínimos Quadrados , Modelos Teóricos
13.
Food Chem ; 456: 140082, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38878532

RESUMO

Establishing a moderate elimination strategy for mycotoxins with the maintained food nutrition is significant to food safety. Herein, the Au-NPs decorated defective Bi2WO6 (Au-BWO-OV) with modulated ROS generation was successfully synthesized, integrating the merits of defect-engineering and Au-NPs induced LSPR-effect. The Au-BWO-OV exhibited modified photoelectrochemical property and O2-adsorption capacity, supporting the selective generation of •O2- and 1O2 with moderate oxidizing ability. As a result, >90% of AFB1 and ZEN were eliminated within 100 and 50 min, along with the maintained nutrition in vegetable oil. Moreover, the reasonable degradation mechanism triggered by •O2- and 1O2 was proposed based on the trapping experiments, DFT calculations and LC-MS analysis for intermediate products, including the steps of hydrolysis, oxidative dissociation, cis-trans isomerization, and dehydroxylation. This work not only paved the way for balancing the contradiction between detoxification and nutrient retention, but also casted new insights into the ROS-mediated degradation mechanism.

14.
Water Res ; 241: 120171, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37295227

RESUMO

Hydrogen sulfide (H2S) production from waste activated sludge (WAS) is the main reason for odor emission during anaerobic fermentation system. CaO has been reported to effectively improve the resources recovery of WAS, but its potential effect on H2S production in anaerobic fermentation process remains unrecognized. In present study, it was found that the addition of 60 mg/g VSS CaO greatly inhibited H2S production and the maximum yield of H2S was 60.1 ± 1.8% lower than the control. Mechanism investigation demonstrated that CaO destroyed sludge structure and increased the release of intracellular organic matter with hydrogen bonding networks destroying, but had a mild effect on the transformation of sulfur containing organic matters and inorganic sulfate reduction. Additionally, the enhancement in H+ and S2- consumption by alkaline condition and metal ions release was another reason for the inhibition of H2S production in CaO addition reactors. Furthermore, microbial analysis showed that CaO addition importantly reduced the hydrolysis microorganism, particularly denitrification hydrolytic bacterias (e.g., unclassified_f_Chitinophagaceae and Dechloromonas), sulfate reducing bacterias (SRBs) (e.g., unclassified_c_Deltaproteobacteria and Desulfosarcina) and genes (e.g., PepD, cysN/D, CysH/C and Sir) involved in organic sulfur hydrolysis and sulfate reduction. Results from this study provides theoretical insights into the practical applications of CaO.


Assuntos
Sulfeto de Hidrogênio , Esgotos , Esgotos/química , Fermentação , Sulfeto de Hidrogênio/análise , Anaerobiose , Enxofre , Ácidos Graxos Voláteis , Concentração de Íons de Hidrogênio
15.
Food Chem ; 405(Pt B): 134895, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36435100

RESUMO

Establishing an effective and sustainable strategy for zearalenone (ZEN) degradation is of great significance to agricultural development and food safety. Herein, more than 98 % of ZEN (2 ppm) was photocatalytic degraded within 90 min over the oxygen-deficient Bi2WO6 ultrathin layers (BWO-U), along with the sharp elimination of biotoxicity to GES-1 cells. Theoretical calculations and characterizations revealed the ultrathin structure and oxygen vacancies endowed BWO-U with strengthened photoelectrochemical activity and O2-adsorption capacity, facilitating the generation of •O2- and 1O2 which play decisive roles in ZEN degradation. Furthermore, a possible mechanism was proposed based on nine intermediates identified via LC-MS, including the steps of cis-trans isomerization, oxidation and cleavage. Eventually, the method also exhibited immense potential in reducing ZEN-contamination in corn oil, and made no significant impact on the quality of corn oil. This work might provide a feasible strategy to mitigate ZEN-contamination and cast a new light on the ROS-mediated mechanism.


Assuntos
Óleo de Milho , Zearalenona , Espécies Reativas de Oxigênio , Adsorção , Oxigênio
16.
Food Res Int ; 165: 112544, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36869531

RESUMO

Edible oils play important roles in biological functions, and triacylglycerols (TAGs) in edible oils are complex mixtures. This makes accurate TAGs quantitation quite difficult that bring economically motivated food adulteration. Herein, we demonstrated a strategy for accurate quantification of TAGs in edible oils, which could be applied in identification of olive oil adulteration. The results showed that the proposed strategy could significantly improve the accuracy of TAG content determination, reduce the relative error of fatty acids (FAs) content determination, and present a wider accurate quantitative range than that of gas chromatography-flame ionization detection. Most important, this strategy coupled with principal component analysis could be used to identify adulteration of high-priced olive oil with cheaper soybean oils, rapeseed oils or camellia oils at a lower concentration of 2%. These findings indicated that the proposed strategy could be regarded as a potential method for edible oils quality and authenticity analysis.


Assuntos
Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta Pressão , Azeite de Oliva , Cromatografia Gasosa-Espectrometria de Massas , Triglicerídeos
17.
Toxins (Basel) ; 15(3)2023 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-36977107

RESUMO

Peanuts are susceptible to aflatoxins produced by Aspergillus flavus. Exploring green, efficient, and economical ways to inhibit Aspergillus flavus is conducive to controlling aflatoxin contamination from the source. In this study, Ag-loaded titanium dioxide composites showed more than 90% inhibition rate against Aspergillus flavus under visible light irradiation for 15 min. More importantly, this method could also reduce the contaminated level of Aspergillus flavus to prevent aflatoxins production in peanuts, and the concentrations of aflatoxin B1, B2, and G2 were decreased by 96.02 ± 0.19%, 92.50 ± 0.45%, and 89.81 ± 0.52%, respectively. It was found that there are no obvious effects on peanut quality by evaluating the changes in acid value, peroxide value, and the content of fat, protein, polyphenols, and resveratrol after inhibition treatment. The inhibition mechanism was that these reactive species (•O2-, •OH-, h+, and e-) generated from photoreaction destroyed cell structures, then led to the reduced viability of Aspergillus flavus spores. This study provides useful information for constructing a green and efficient inhibition method for Aspergillus flavus on peanuts to control aflatoxin contamination, which is potentially applied in the field of food and agri-food preservation.


Assuntos
Aflatoxinas , Aspergillus flavus , Aspergillus flavus/metabolismo , Arachis/química , Aflatoxina B1/toxicidade , Aflatoxina B1/metabolismo
18.
J Hazard Mater ; 441: 129853, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36084459

RESUMO

Sensitive, on-site and multiple detection of mycotoxins is a vital early-warning tool to minimize food losses and protect human health and the environment. Although paper-based lateral flow immunoassay (LFIA) has been extensively applied in mycotoxins monitoring, low-cost, portable, ultrasensitive and quantitative detection is still a formidable challenge. Herein, a series of Fe-N-C single-atom nanozymes (SAzymes) were synthesized and systematic characterized. The optimal Fe-N-C SAzyme with highly efficient catalytic performance was successfully used as both label and catalyst in lateral flow immunoassays for mycotoxin detection. By taking advantage of the catalytic amplified system, the qualitative and quantitative detection can be easily and flexibly done via observing the test lines by naked eyes or a smartphone, with the limit of detections (LODs) of 2.8 and 13.9 pg mL-1 for AFB1 and FB1, which were respectively over 700- and 71,000-fold lower than the maximum limit set by the European Union. Besides, underlying catalytic mechanisms and the active sites of the Fe-N-C SAzyme are also investigated by DFT simulation. This work not only provides a promising detection strategy for the application of advanced SAzymes but also offers experimental and theoretical guidelines to understand the active centers of Fe-N-C SAzymes and the catalytic process.


Assuntos
Micotoxinas , Catálise , Humanos , Imunoensaio , Limite de Detecção , Micotoxinas/análise
19.
Light Sci Appl ; 12(1): 28, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36693852

RESUMO

SiC semiconductor is the focus of recent international research. It is also an important raw material for China to achieve carbon emission peak and carbon neutrality. After nearly 20 years of research and development, we focus on the three types SiC crystals, n-type, p-type and semi-insulating, indicating the development of Shandong University for crystal growth. And defects control, electrical property, atomic polishing, and corresponding device authentication all obtain great progress. Total dislocation density of 6-inch n-type substrates decreases to 2307 cm-2, where BPD (Basal Plane Dislocation) lowers to 333 cm-2 and TSD (Threading Screw Dislocation) 19 cm-2. The full width at half maximum (FWHM) (0004) rocking curves is only 14.4 arcsec. The resistivity reaches more than 1E + 12 Ω·cm for semi-insulating SiC and lower than 20 mΩ·cm for n-type SiC. The impurity concentrations in 6-inch high-purity semi-insulating (HPSI) SiC crystals reach extreme low levels. The devices made of various substrate materials have good performance.

20.
ACS Appl Mater Interfaces ; 14(24): 28021-28032, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35675545

RESUMO

Aspergillus flavus is a kind of widespread fungi that can produce carcinogenic, teratogenic, and mutagenic secondary metabolites known as aflatoxins. Aspergillus flavus mainly spread through the means of fungal spores in air, thus preventing the spores spread is an effective strategy to control aflatoxins contamination from source. Herein, a rapid and efficient control way to prevent the spread of Aspergillus flavus spores in air was demonstrated. Ag-AgCl nanoparticles were combined with tetrahedral α-Fe2O3 to form plasmonic composites that presented 93.65 ± 1.53% prevention rate of Aspergillus flavus spores under 50 min visible light irradiation. The efficient activity was attributed to the synergy effect of Ag including intrinsic disinfection, electron sink, and localized surface plasmon resonance effect, which were proven by photoelectric characterization, density functional theory, and finite difference time domain methods. The calculated work functions of α-Fe2O3, Ag, and AgCl were 3.71, 4.52, and 5.38 eV, respectively, which could accelerate photoinduced carrier transfer through Ag during photoreaction. Moreover, it was found that the intrinsic disinfection of Ag and hydroxyl radical from photocatalytic reaction were the main factors to the prevention of Aspergillus flavus spores, which resulted in the destruction of spore structure and the leakage of intracellular protein with 62.15 ± 2.63 µg mL-1. Most important, it was proven that the composites also showed high activity (90.52 ± 1.26%) to prevent Aspergillus flavus spore spread in the storage process of peanuts. These findings not only provided useful information for an efficient and potential strategy to prevent Aspergillus flavus contamination but also could be as a reference in toxic fungi control.


Assuntos
Aflatoxinas , Aspergillus flavus , Aflatoxinas/metabolismo , Aflatoxinas/farmacologia , Aspergillus flavus/metabolismo , Luz , Esporos Fúngicos , Ressonância de Plasmônio de Superfície
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