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1.
Small Methods ; 6(1): e2101186, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35041283

RESUMO

Interfacial microenvironment modulation has been proven to be a promising route to fabricate highly efficient catalysts. In this work, the lattice defect-rich NiS2 /MoS2 nanoflakes (NMS NFs) electrocatalysts are successfully synthesized by a simple strategy. Benefiting from the abundant lattice defects and modulated interfacial microenvironment between NiS2 and MoS2 , the prepared NMS NFs show superior catalytic activity for water splitting. Particularly, the optimized NMS NFs (the molar ratio of Ni:Mo = 5:5) exhibit remarkable catalytic activity toward overall water splitting with a voltage of 1.60 V at 10 mA cm-2 in alkaline media, which is lower than that of the noble-metal-based electrocatalysts (1.68 V at 10 mA cm-2 ). The NMS NFs electrocatalysts also show exceptional long-term stability (>50 h) for overall water splitting. The density functional theory results demonstrate that the injection of NiS2 into MoS2 can greatly optimize the catalytic kinetics and reduce the energy barrier for hydrogen/oxygen evolution reactions. The work does not only offer a promising candidate for a highly efficient water splitting electrocatalyst but also highlights that interfacial microenvironment modulation is a potential strategy to optimize the catalytic kinetics.

2.
ACS Appl Mater Interfaces ; 13(48): 58085-58095, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34826222

RESUMO

Many researchers have contributed to the assembly of zeolitic nanosheets and nanocrystallites into three-dimensional (3D) networks as it can remarkably improve the catalytic and/or adsorptive performances of zeolites. However, the applications of these synthesized materials are seriously limited because of low hydrothermal stability. A highly interesting strategy, but a great challenge, is the alignment of well-crystallized zeolite crystals into desirable architectures. Here, well-crystallized silicalite-1 crystals are assembled like toy Lego bricks into one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) architectures, and the assembly mechanism is investigated by combining elaborate experiments, in situ spectroscopy, and theoretical calculations. A 1D architecture was formed by stacking crystals along the b axis with the assistance of ethanol that is selectively adsorbed on (100) and (001) crystal facets. Such adsorption increases the condensation energy barriers along a and c axes, but facilitates the condensation between (010) facets. The assembly of the crystals into well-arrayed 2D architectures is achieved using both ethanol and benzaldehyde because of their preferable adsorption on the (001) facet. When an amphiphilic copolymer (P123) was further added in the gel along with the substitution of ethanol by 1-propanol, a 3D network was fabricated by the agglomeration and self-pillaring of the 2D Lego bricks possibly with P123 aggregates as the substrate matrix. Excitingly, upon alignment of crystals into 2D architectures, the adsorptive selectivity of 1-butanol (2 wt %) to water of silicalite-1 increases by 45.3 times, while into 3D networks, the catalytic activity for the Beckmann rearrangement of cyclohexanone oxime elevates by 79% along with a great enhancement of catalytic stability.

3.
Sensors (Basel) ; 21(22)2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34833581

RESUMO

Robot-assisted minimally invasive surgery (MIS) has received increasing attention, both in the academic field and clinical operation. Master/slave control is the most widely adopted manipulation mode for surgical robots. Thus, sensing the force of the surgical instruments located at the end of the slave manipulator through the main manipulator is critical to the operation. This study mainly addressed the force detection of the surgical instrument and force feedback control of the serial surgical robotic arm. A measurement device was developed to record the tool end force from the slave manipulator. An elastic element with an orthogonal beam structure was designed to sense the strain induced by force interactions. The relationship between the acting force and the output voltage was obtained through experiment, and the three-dimensional force output was decomposed using an extreme learning machine algorithm while considering the nonlinearity. The control of the force from the slave manipulator end was achieved. An impedance control strategy was adopted to restrict the force interaction amplitude. Modeling, simulation, and experimental verification were completed on the serial robotic manipulator platform along with virtual control in the MATLAB/Simulink software environment. The experimental results show that the measured force from the slave manipulator can provide feedback for impedance control with a delay of 0.15 s.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Cirurgia Assistida por Computador , Desenho de Equipamento , Retroalimentação , Procedimentos Cirúrgicos Minimamente Invasivos
4.
Artigo em Inglês | MEDLINE | ID: mdl-34758920

RESUMO

Nowadays, the fabrication of robust and earth-abundant hydrogen evolution electrocatalysts with noble-metal-like catalytic activities is still facing great challenges. In this report, nanorod (NR)-shaped nickel sulfide (NiS) is successfully decorated on graphene (Gr) by utilizing carbon cloth (CC) as a substrate (NiS-Gr-CC). Benefiting from the NR morphology and strong interfacial synergetic effect between NiS and Gr, the NiS-Gr-CC electrocatalyst shows good catalytic activity for hydrogen evolution reaction (HER). Specifically, the low Tafel slopes of 46 and 56 mV dec-1 along with the small overpotentials of 66 and 71 mV at 10 mA cm-2 are obtained in the acidic and alkaline electrolytes, respectively. Density functional theory results indicate that the combination of NiS and Gr can optimize the adsorption energy of H* during the HER process. The long-term durability measurement result reveals that our NiS-Gr-CC heterostructure has good electrocatalytic cycling stability (∼80 h) in both acidic and alkaline electrolytes. These results confirm that the NiS-Gr-CC heterostructure is a promising candidate for hydrogen evolution electrocatalyst with high catalytic activity.

5.
J Am Chem Soc ; 143(40): 16641-16652, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34606264

RESUMO

Enzymatic microarchitectures with spatially controlled reactivity, engineered molecular sieving ability, favorable interior environment, and industrial productivity show great potential in synthetic protocellular systems and practical biotechnology, but their construction remains a significant challenge. Here, we proposed a Pickering emulsion interface-directed synthesis method to fabricate such a microreactor, in which a robust and defect-free MOF layer was grown around silica emulsifier stabilized droplet surfaces. The compartmentalized interior droplets can provide a biomimetic microenvironment to host free enzymes, while the outer MOF layer secludes active species from the surroundings and endows the microreactor with size-selective permeability. Impressively, the thus-designed enzymatic microreactor exhibited excellent size selectivity and long-term stability, as demonstrated by a 1000 h continuous-flow reaction, while affording completely equal enantioselectivities to the free enzyme counterpart. Moreover, the catalytic efficiency of such enzymatic microreactors was conveniently regulated through engineering of the type or thickness of the outer MOF layer or interior environments for the enzymes, highlighting their superior customized specialties. This study provides new opportunities in designing MOF-based artificial cellular microreactors for practical applications.

6.
Nano Lett ; 21(19): 8455-8465, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34569805

RESUMO

Golgi apparatus is a major subcellular organelle responsible for drug resistance. Golgi apparatus-targeted nanomechanical disruption provides an attractive approach for killing cancer cells by multimodal mechanism and avoiding drug resistance. Inspired by the poisonous twisted fibrils in Alzheimer's brain tissue and enhanced rigidity of helical structure in nature, we designed transformable peptide C6RVRRF4KY that can self-assemble into nontoxic nanoparticles in aqueous medium but transformed into left-handed helical fibrils (L-HFs) after targeting and furin cleavage in the Golgi apparatus of cancer cells. The L-HFs can mechanically disrupt the Golgi apparatus membrane, resulting in inhibition of cytokine secretion, collapse of the cellular structure, and eventually death of cancer cells. Repeated stimulation of the cancers by the precursors causes no acquired drug resistance, showing that mechanical disruption of subcellular organelle is an excellent strategy for cancer therapy without drug resistance. This nanomechanical disruption concept should also be applicable to multidrug-resistant bacteria and viruses.


Assuntos
Nanopartículas , Neoplasias , Complexo de Golgi , Humanos , Neoplasias/tratamento farmacológico
7.
Sci Rep ; 11(1): 19370, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34588471

RESUMO

In this paper, the MIL-53(Al)-NH2 metal-organic frameworks (MOFs) was prepared based on the anodic electrosynthesis under green conditions. The anodic electrosynthesis as an environmentally friendly procedure was performed in the aqueous solution, room temperature, atmospheric pressure, and in the short reaction time (30 min). Also, the employed procedure was accomplished without the need for the ex-situ salt and base/probase additives as cation source and ligand activating agent at the constant current mode (10.0 mA cm-2). The electrosynthesized MOFs was functionalized with phosphorus acid tags as a novel mesoporous catalyst. This mesoporous catalyst was successfully employed for synthesis of new series (N-methyl-pyrrol)-pyrazolo[3,4-b]pyridines by one-pot condensation reaction of 3-methyl-1-phenyl-1H-pyrazol-5-amine, 3-(1-methyl-1H-pyrrol-2-yl)-3-oxopropanenitrile and various aromatic aldehydes (mono, bis and tripodal). This catalyst proceeded the organic synthetic reaction via a cooperative vinylogous anomeric based oxidation mechanism with a marginal decreasing its catalytic activity after recycling and reusability.

8.
Nano Lett ; 21(16): 7005-7011, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34350759

RESUMO

The Mott state in 1T-TaS2 is predicted to host quantum spin liquids (QSLs). However, its insulating mechanism is controversial due to complications from interlayer coupling. Here, we study the charge transfer state in monolayer 1T-NbSe2, an electronic analogue to TaS2 exempt from interlayer coupling, using spectroscopic imaging scanning tunneling microscopy and first-principles calculations. Monolayer NbSe2 surprisingly displays two types of star of David (SD) motifs with different charge transfer gap sizes, which are interconvertible via temperature variation. In addition, bilayer 1T-NbSe2 shows a Mott collapse by interlayer coupling. Our calculation unveils that the two types of SDs possess distinct structural distortions, altering the effective Coulomb energies of the central Nb orbital. Our calculation suggests that the charge transfer gap, the same parameter for determining the QSL regime, is tunable with strain. This finding offers a general strategy for manipulating the charge transfer state in related systems, which may be tuned into the potential QSL regime.

9.
Sci Rep ; 11(1): 16817, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413353

RESUMO

A metal-organic framework (MOF) with sulfonic acid tags as a novel mesoporous catalyst was synthesized. The precursor of Zr-UiO-66-PDC was synthesized both via chemical and electrochemical methods. Then, zirconium-based mesoporous metal-organic framework [Zr-UiO-66-PDC-SO3H]Cl was prepared by reaction of Zr-UiO-66-PDC and SO3HCl. The structure of [Zr-UiO-66-PDC-SO3H]Cl was confirmed by FT-IR, PXRD, FE-SEM, TEM, BET, EDX, and Mapping analysis. This mesoporous [Zr-UiO-66-PDC-SO3H]Cl was successfully applied for the synthesis of dicyanomethylene pyridine derivatives via condensation of various aldehyde, 2-aminoprop-1-ene-1,1,3-tricarbonitrile and malononitrile. At the electrochemical section, a green electrochemical method has successfully employed for rapid synthesis of the zirconium-based mesoporous metal-organic framework UiO-66-PDC at room temperature and atmospheric pressure. The synthesized UiO-66-PDC has a uniform cauliflower-like structure with a 13.5 nm mean pore diameter and 1081.6 m2 g-1 surface area. The described catalyst [Zr-UiO-66-PDC-SO3H]Cl was also employed for the convergent paired electrochemical synthesis of dihydropyridine derivatives as an environmentally friendly technique under constant current at 1.0 mA cm-2 in an undivided cell. The proposed method proceeds with moderate to good yields for the model via a cooperative vinylogous anomeric based oxidation.

10.
Huan Jing Ke Xue ; 42(9): 4520-4526, 2021 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-34414752

RESUMO

Nanoscale zero-valent iron (nZVI) shows excellent reduction of Cr(Ⅵ), but the passivation on its outer surface can restrict its longevity and performance. To tackle this problem, this work introduced Shewanella oneidensis MR-1, a dissimilatory iron-reducing bacterium, into the chemical reduction system of aged nZVI/biochar (B) and Cr(Ⅵ). The potential synergistic effect of Cr(Ⅵ) reduction of aged nZVI/B and MR-1 was systematically investigated under varying conditions. The results indicated that aged nZVI/B and MR-1 exhibited a synergistic effect at a pH of 7, and the removal rate of Cr(Ⅵ) increased by 51.3%. Further research showed that the synergistic effect could be attenuated with the increase in the initial Cr(Ⅵ) concentration and enhanced with the increase in the MR-1 concentration. The XPS spectra confirmed that Cr(Ⅵ) was mainly removed through reduction. The dissimilatory iron-reducing ability of MR-1 played a key role in enhancing the Cr(Ⅵ) reduction. The reductive dissolution of the oxidation layers not only released reactive sites inside the nZVI, but also reduced Cr(Ⅵ) by producing ferrous ions. Moreover, B promoted the reduction by dispersing the nZVI and mediating the extracellular electron transfer. This study provides a new insight into solving the passivation problem of the long-term application of nZVI for Cr(Ⅵ) removal, which is considered a promising solution for synergistically improving the performance of nZVI in environmental remediation.


Assuntos
Ferro , Poluentes Químicos da Água , Carvão Vegetal , Cromo , Shewanella , Poluentes Químicos da Água/análise
11.
ACS Chem Neurosci ; 12(14): 2705-2711, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34240598

RESUMO

As an intrinsic origin cause, histidine behaviors play a critical role in protein misfolding processes. Generally, the English (H6R) mutation will disrupt H6 interactions. However, the structural properties of Aß40 H6R and Aß42 H6R under the complex influence of a histidine tautomeric effect and an H6R mutation remain unclear. Therefore, we performed a replica exchange molecular dynamics simulation to unveil such structural properties. Our result showed that the H6R substitute could promote the generation of ß-sheet structures in comparison to the wild type. Three ß-strand structure properties were observed in Aß40 (rδδ), Aß42 (rεε), Aß42 (rεδ), and Aß42 (rδδ) with ß-sheet contents of 47.5%, 37.2%, 46.9%, and 38.6%, respectively, and the dominant conformational properties of Aß40 (rδδ), Aß42 (rεε), Aß42 (rεδ), and Aß42 (rδδ) had top conformational states of 86.0%, 73.2%, 67.0%, and 56.5%, respectively. Further analysis confirmed that R6 had different mechanisms for controlling the conformational features in Aß40 H6R and Aß42 H6R. In the Aß40 systems, H14 H-bond networks played a critical role in controlling the structural properties. However, in the Aß42 systems, R6 was more important because it was directly involved in the ß-strand formation and maintained the ß-sheet between the N-terminus and the central hydrophobic core region. Our current study helps to elucidate the histidine tautomeric behaviors in H6R mutations, which will present opportunities to understand the correlation between with/without H6 and the Aß40/Aß42 H6R misfolding mechanisms.


Assuntos
Doença de Alzheimer , Histidina , Peptídeos beta-Amiloides/genética , Histidina/genética , Humanos , Mutação/genética , Fragmentos de Peptídeos/genética
12.
Neuroreport ; 32(12): 1049-1057, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34232131

RESUMO

Depression is one of the most common and disabling mental disorders. There is growing evidence that 5-HT1A receptor is involved in the regulation of depressive-related behaviors. However, the exact mechanism underlying the role of 5-HT1A receptor in depression remains unknown. Histone acetylation is associated with the pathophysiology and treatment of depression. In the current study, we investigated whether the epigenetic histone deacetylase (HDAC)-induced histone acetylation mediates the regulation of 5-HT1A receptor in depressive behaviors. We showed that 5-HT1A receptor selective agonist (±)-8-hydroxy-2-(dipropylamino) tetralin hydrobromide led to significant increase in acetylation of H3 at lysine 9 (Ac-H3K9) and H4 at lysine 5 (Ac-H4K5) and lysine 12 (Ac-H4K12) with obviously decreasing histone deacetylase 1 (HDAC1), histone deacetylase 2 (HDAC2), histone deacetylase 4 (HDAC4) and histone deacetylase 5 (HDAC5) expression in hippocampus of mice. Conversely, 5-HT1A receptor selective antagonist NAN-190 decreased the level of acetylation of H3 and H4 with increasing the expression of HDAC1, HDAC2, HDAC4 and HDAC5 in the hippocampus. Furthermore, we found that HDAC inhibitors, trichostatin A or suberoylanilide hydroxamic acid infusion to hippocampus prevented the depressive behaviors induced by NAN-190, as well as histone H3 and H4 acetylation in mice. Our results suggested that epigenetic histone acetylation coupled with 5-HT1A receptor may play vital role in the pathophysiology and treatment of depressive disorders.

13.
ACS Omega ; 6(25): 16488-16497, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34235320

RESUMO

Aluminum hydroxide is an effective defluoridation adsorbent; however, the poor defluoridation performance limits its wide application. In this work, amorphous and crystalline AlOOH adsorbents are synthesized through hydrolysis of Al salts, and their defluoridation performances are evaluated in terms of adsorption capacity and rate, sensitivity to pH value, and water quality after defluoridation. The defluoridation performance of AlOOH is closely related to the hydrolysis pH value, but hardly to the type of Al salts. The adsorbent can remove >95% fluoride in the first 2 min and reach adsorption equilibrium within 2 h, and the maximum defluoridation capacity is 41.9 mg/g. Furthermore, the adsorbent exhibits an excellent defluoridation efficiency at a wide pH range of 4.5-10.5. After fluoride removal, the adsorbents prepared at pH values of 6 and 7 exhibit low residual Al concentration. The Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results confirm that the fluoride removal mechanism is the ligand exchange between fluoride and hydroxyl groups. The excellent defluoridation capacity and low residual Al demonstrate that AlOOH is a potential adsorbent for fluoride separation from water.

14.
Biosens Bioelectron ; 189: 113356, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34077863

RESUMO

In this study, a DYS14 aptamer/polyaniline-reduced graphene oxide-gold nanoparticles/gold (Apt/PANi-RGO-G*NPs/Au) electrode was fabricated to detect the Y-chromosome DYS14 DNA sequence in cffDNA in the blood plasma of pregnant women and used on real and laboratory samples with high success rate. The electrochemical properties of the prepared E-DNA biosensor were characterized by CV, SWV, XRD, and EIS. The E-DNA biosensor morphological characteristics were investigated by TEM, SEM, and EDX. Phosphorothioate was used to link the aptamer to PANi-RGO-G*NPs modified gold electrode. This is due to control of the adsorption polarity and increase adsorption stability. Under optimized conditions, the linear range of the analytical technique with respect to the logarithm of the target sequence concentration was 1.0 × 10-16-1.0 × 10-8 M, the detection limit was 4.26 × 10-17 M, and the limit of quantitation was 1.422 × 10-16 M. The E-DNA biosensor displayed high selectivity and sensitivity, high efficiency, and acceptable repeatability. For fetal sex detection, 12 pregnant women from the 5th to the 15th week of gestation participated in the study. Results indicated the fabricated Apt/PANi-RGO-G*NPs/Au E-DNA biosensor to be appropriate for fetal sex determination in pregnant women between the 7th and 9th week of gestation. Notably, this method can be used as a model for the study of pathogens like bacteria and viruses.


Assuntos
Técnicas Biossensoriais , Ácidos Nucleicos Livres , Grafite , Nanopartículas Metálicas , DNA/genética , Técnicas Eletroquímicas , Eletrodos , Feminino , Ouro , Humanos , Gravidez
15.
iScience ; 24(5): 102503, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34113834

RESUMO

The stability of protein structures and biological functions at normal temperature is closely linked with the universal aqueous environment of organisms. Preserving bioactivities of proteins in hyperthermia water would expand their functional capabilities beyond those in native environments. However, only a limited number of proteins derived from hyperthermophiles are thermostable at elevated temperatures. Triggered by this, here we describe a general method to stabilize mesophilic proteins in hyperthermia water. The mesophilic proteins, protected by amphiphilic polymers with multiple binding sites, maintain their secondary and tertiary structures after incubation even in boiling water. This approach, outside the conventional environment for bioactivities of mesophilic proteins, provides a general strategy to dramatically increase the Tm (melting temperature) of mesophilic proteins without any changes to amino sequences of the native proteins. Current work offers a new insight with protein stability engineering for potential application, including vaccine storage and enzyme engineering.

16.
Int J Occup Saf Ergon ; : 1-8, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34126878

RESUMO

Previous studies have concentrated on the value of managerial leadership for safety behavior conduct by employees in the workplace. However, safety leadership styles concerning mindful safety practices have rarely been examined. The goal of this study is therefore to investigate the relationships between safety-specific leaderships (transformational and active transactional leadership) and the adoption of mindful safety practices among first-line workers mediated by safety climate in the Chinese petroleum industry. Data were obtained from first-line workers in two Chinese petroleum companies. PLS-SEM results show that transformational and active transactional leadership are positively related to safety climate, which in turn affects mindful safety practice adoption in the Chinese petroleum industry. The results of the current study indicate that transformational and active transactional leadership in a safety-specific view offer a comprehensive leadership model for mindful safety practices conduct in the Chinese petroleum industry.

17.
Chem Commun (Camb) ; 57(41): 5086-5089, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33899849

RESUMO

Herein, we synthesized an oxygen- and nitrogen-containing carbonaceous structure (ONCS). This ONCS possessed exceptional light-harvesting ranging from the visible to NIR light region. Characterization results confirmed that the ONCS was an n-type semiconductor. The ONCS can efficiently catalyze hydrogen photosynthesis and benzyl alcohol oxidation under visible light, even under NIR light irradiation.

18.
Int J Occup Saf Ergon ; : 1-8, 2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33704011

RESUMO

The petroleum industry is a high-risk industry and operates under the social technical system. Therefore, the safety behavior of employees needs to be paid high attention. Thus, six dimensions of safety management practices are identified as independent variables to predict a special component of common safety behavior-mindful safety practices in the Chinese petroleum industry. High-reliability organization theory is adopted as the underpinning theory. A total 255 first-line workers from a Chinese petroleum company participated in this survey. The results reveal that safety training and safety communication and feedback are positively related to safety motivation. Moreover, workers' involvement and safety promotion policy have direct and positive impacts on mindful safety practices. Further, safety motivation is found to play a mediating role in the prediction of mindful safety practices in the Chinese petroleum industry. These findings give new insights for petroleum companies into how to promote mindful safety practices in the workplace.

19.
Phys Chem Chem Phys ; 23(6): 4030-4038, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33554982

RESUMO

By means of density functional theory (DFT) computations, we explored the potential of carbon- and nitrogen-doped Mo2P (CMP and NMP) layered materials as the representative of transition metal phosphides (TMPs) for the development of lithium-ion battery (LIB) anode materials, paying special attention to the synergistic effects of the dopants. Both CMP and NMP have exceptional stabilities and excellent electronic conductivity, and a high theoretical maximum storage capacity of ∼ 486 mA h g-1. Li-ion diffusion barriers on the two-dimensional (2D) CMP and NMP surfaces are extremely low (∼0.036 eV), and it is expected that on these 2D layers Li can diffuse 104 times faster than that on MoS2 and graphene at room temperature, and both monolayers have relatively low average open-circuit voltage (0.38 and 0.4 eV). All these exceptional properties make CMP and NMP monolayers as promising candidates for high-performance LIB anode materials, which also demonstrates that simple doping is an effective strategy to enhance the performance of anode materials in rechargeable batteries.

20.
Food Microbiol ; 95: 103669, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33397632

RESUMO

Fungal contamination is a concern for the food industry. Fungal spores resist food sterilization treatments and produce mycotoxins that are toxic for animals and humans. Technologies that deactivate spores and toxins without impacting food quality are desirable. This study demonstrates the efficiency of a high voltage atmospheric cold plasma (HVACP) technology using air to generate reactive oxygen (ROS) and nitrogen (RNS) species for the degradation of Aspergillus flavus cultures and the deoxynivalenol (DON) mycotoxin. Optical emission and absorption spectroscopy demonstrate ionization of hydroxyl groups, atomic oxygen and nitrogen, and confirm production of ROS and RNS, e.g. O3, NO2, NO3, N2O4, and N2O5. Fungal cultures show a depletion in pigmentation and an ~50% spore inactivation after 1-min treatments. Treated spores show surface ablation and membrane degradation by scanning electron microscopy. Twenty-minute direct HVACP treatments of 100 µg of DON in one mL aqueous suspensions resulted in a greater than 99% reduction in DON structure and rescued over 80% of Caco-2 cell viability; however, the same treatment on 100 µg of powdered DON toxin only showed a 33% reduction in DON and only rescued 15% of cell viability. In summary, HVACP air treatment can inactivate both fungal spores and toxins in minutes.


Assuntos
Aspergillus flavus/efeitos dos fármacos , Gases em Plasma/farmacologia , Esporos Fúngicos/crescimento & desenvolvimento , Tricotecenos/metabolismo , Aspergilose/microbiologia , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/metabolismo , Células CACO-2 , Humanos , Gases em Plasma/química , Espécies Reativas de Oxigênio/metabolismo , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/metabolismo
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