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1.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 56(2): 182-189, 2021 Feb 09.
Artigo em Chinês | MEDLINE | ID: mdl-33557503

RESUMO

Objective: To study the influence of non-thermal atmospheric pressure plasma (NTAPP) on dentine surface temperature, wettability and morphology of collagen fibrils under different treatment condition. Methods: Helium was used as the operating gas at the flow rate of 3, 4, 5 L/min respectively. The plasma jet was operated at various input power of 8, 9, 10, 11 W. Thermal accumulation on human dentine surface (6 specimens per group, acquired from Department of Stomatology, The First Affiliated Hospital of Xi'an Medical University and Department of Stomatology, The Second Affiliated Hospital of Xi'an Medical University) of each group was measured continuously at 5 s intervals for 60 s by infrared thermography. Mean values were calculated and temperature curves were drawn. Dentine surface contact angles were measured after NTAPP treatment for 5, 10, 15, 20 s with gas flow rate and input power described above. The micro structure of the collagen fibrils of the negative control group (without NTAPP treatment) and NTAPP treatment groups (5 L/min gas flow rate, input power of 8, 9, 10, 11 W and treating time for 5, 10, 15, 20 s) was observed by field emission scanning electron microscopy (FE-SEM). All data were analyzed by SPSS 18.0. Results: Input power, gas flow and treatment time all showed significant influences on dentine surface temperature and wettability (P<0.01). Dentine temperature rose along with time. The greater input power was, the higher dentine temperature was. The greater gas flow rate was, the faster the temperature rose. Dentine surface temperature reached the highest point of (35.10±0.24) ℃ with NTAPP treatment for 60 s, at input power of 11 W and flow rate of 5 L/min. The contact angles of each experimental group decreased with time, and significant differences were found in the contact angles between the experimental groups and the negative control group (75.57°±1.45°). The contact angles showed a decreasing trend as the input power and the gas flow rate increased. The contact angles reached the lowest point of 13.19°±2.01° with NTAPP treatment for 20 s, at input power of 10 W and flow rate of 5 L/min. The FE-SEM results showed that, along with the increase of input power and extension of time, the demineralized collagen fibrils were destroyed in varying degrees. The collagen fibrils were curled, fractured, fused, and even disappeared. Conclusions: NTAPP could significantly increase the surface temperature, modify dentine wettability and alter the micro structure, which was significantly influenced by input power, gas flow rate and treating time.


Assuntos
Dentina , Gases em Plasma , Humanos , Microscopia Eletrônica de Varredura , Plasma , Propriedades de Superfície
2.
Am J Vet Res ; 82(2): 118-124, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33480278

RESUMO

OBJECTIVE: To determine whether a stainless steel implant sterilized with a novel cold atmospheric plasma sterilization (CAPS) device adversely affects local tissues in rabbits and whether CAPS was as effective as steam sterilization with an autoclave to inactivate Pasteurella multocida. ANIMALS: 31 healthy New Zealand White rabbits. PROCEDURES: Steam-autoclaved stainless steel implants inoculated with P multocida underwent a second steam autoclave sterilization (AIA) or CAPS (AICAPS). One AIA implant and 3 AICAPS implants were randomly placed subcutaneously at 4 sites in 21 rabbits (84 implants). These rabbits were monitored daily for 5 days for evidence of systemic illness and local tissue reactions at the implantation sites and then euthanized. Samples were taken from each implant site for bacterial culture and histologic examination. RESULTS: Cultures of samples obtained from all sites were negative for bacterial growth. No significant difference was observed in mean skin thickness or erythema between AIA and AICAPS implant sites on any observed day. Also, individual histologic grades for the epidermis, dermis, subcutis, and muscle and total histologic grade were not significantly different between AIA and AICAPS implant sites. CONCLUSIONS AND CLINICAL RELEVANCE: Cold atmospheric plasma sterilization was noninferior to steam sterilization of P multocida-contaminated stainless steel implants in the rabbits in the present study. However, studies of the efficacy of CAPS for inactivation of other important bacteria are needed.


Assuntos
Corpos Estranhos , Pasteurella multocida , Gases em Plasma , Animais , Corpos Estranhos/veterinária , Plasma , Coelhos , Esterilização
3.
Food Chem ; 346: 128974, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33465571

RESUMO

The effects of argon and nitrogen cold plasma treatments on the lipolytic enzymes activity in wheat germ were investigated. Using argon as plasma gas, the residual activity of lipase and lipoxygenase decreased to 42.50% and 87.72%, respectively after 30 min. Switching plasma input gas to nitrogen, the residual activities of lipase and lipoxygenase after the same time of atmospheric cold plasma (ACP) treatment were 77.50% and 92.52%, respectively. The antioxidant potential and phenolic compounds show no significant difference during ACP duration. However, the remaining activities of lipase and lipoxygenase after 30 min steam autoclaving were 6.25% and 18.60%, respectively. Also, the antioxidant activity and total phenolic content reduced by 14.70% and 30.80%, respectively. In brief, the ACP treatment efficiency was function of the input gas and the treatment time. The presented results about the input gas impacts would be useful in industrial development of ACP application for wheat germ stabilization.


Assuntos
Lipase/metabolismo , Lipoxigenase/metabolismo , Gases em Plasma/química , Triticum/enzimologia , Antioxidantes/química , Argônio/química , Nitrogênio/química , Fenóis/química , Temperatura , Triticum/química
4.
Bioresour Technol ; 323: 124621, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33412497

RESUMO

In this study, the long-acting mechanism of reactive species was investigated for enhanced ethanol production of Saccharomyces cerevisiae. The results indicated that short-lifetime active species from gas phase plasma dissolved into various liquid microenvironments with different media (water, buffer, medium, and cells), forming different types and amounts of reactive species in multi-scale microenvironments, such as extracellular reactive nitrogen species, endocellular reactive oxygen and nitrogen species. The sustained elevation of cytoplasm calcium concentration with treatment time depended on the activated calcium channels of Cch1p/Mid1p in cell membrane and Yvc1p in vacuole membrane by these species. Accordingly, the Ca2+ increase promoted the H+-ATPase expression. Consequently, 75.6% ATP hydrolysis induced about 5 fold NADH increase compared with the control. Ultimately, the bioethanol yield increased by 34.2% compared to the control. These results promote the development of atmospheric cold plasma as a promising bio-process enhancement technology for improved target product yields of microbes in fermentation industry.


Assuntos
Gases em Plasma , Proteínas de Saccharomyces cerevisiae , Etanol , Fermentação , Plasma/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
5.
Food Chem ; 337: 127783, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32791427

RESUMO

Jujube slices were pretreated by cold plasma for 15, 30, and 60 s on each side, followed by hot air drying at 50, 60, and 70 °C. Scanning electron microscopy investigation indicated that the application of cold plasma significantly changed the surface topography of jujube slice by etching larger cavities, which can facilitate moisture transfer and consequently enhance drying rate and effective diffusivity. Modified Henderson & Pabis model and Two-term model were the two most recommended models for describing the drying kinetics of jujube slices. Cold plasma pretreatment improved the contents of procyanidins, flavonoids, and phenolics by 53.81%, 33.89%, and 13.85% at most, respectively, and thereby enhanced antioxidant capacity by 36.85% at most. Besides, cold plasma pretreatment can reduce the production of 5-hydroxymethylfurfural by 52.19% at most. In summary, cold plasma can be used as a promising pretreatment tool for drying processes of jujube slices.


Assuntos
Dessecação/métodos , Manipulação de Alimentos/métodos , Frutas/química , Gases em Plasma , Ziziphus/química , Antioxidantes/análise , Flavonoides/análise , Cinética , Fenóis/análise , Proantocianidinas/análise
6.
Chemosphere ; 263: 127893, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32835971

RESUMO

Toluene and styrene were two typical aromatic VOCs which were commonly used and coexistence in the exhaust gases from industrial manufacturing. Their simultaneous removal performances under non-thermal plasma (NTP) and NTP-catalysis were carried out and compared by a single stage coaxial dielectric barrier discharge (DBD) reactor. The effects of VOCs mixture, humidity, materials filling in the discharge zoon on the removal efficiency, COx selectivity, byproducts types and their emission levels were deeply investigated to explore the degradation mechanism and coexistence effect. Experimental results showed that the toluene removal was significantly inhibited when treated together with styrene under plasma treatment. But that of styrene was hardly affected at the same conditions. It was found that benzaldehyde as the primary organic byproducts from styrene consumed the oxidizing particles (O and . OH), limiting the conversion of toluene. The introduction of Cu-doped MnO2 materials significantly improved the VOCs removal performance with nearly 100% conversion to COx at a discharge power less than 30 W, as well as O3 generation from more than 1.2 mg L-1 by NTP to 1.6 × 10-3 mg L-1 by NTP-catalysis. With the help of in situ FT-IR, it was believed that catalysts not only accelerated the adsorption and degradation of pollutants but also utilized ozone to involve this process. At last, a plausible explanation on binary coexistence effect under different conditions had been suggested and discussed.


Assuntos
Tolueno/química , Compostos Orgânicos Voláteis/química , Adsorção , Catálise , Compostos de Manganês , Óxidos , Ozônio , Gases em Plasma , Espectroscopia de Infravermelho com Transformada de Fourier , Estireno
7.
Water Res ; 188: 116513, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33091801

RESUMO

Although the identification of effective reactive oxygen species (ROS) generated by plasma has been extensively studied, yet the subcellular mechanism of microbial inactivation has never been clearly elucidated in plasma disinfection processes. In this study, subcellular mechanism of yeast cell inactivation during plasma-liquid interaction was revealed in terms of comprehensive factors including cell morphology, membrane permeability, lipid peroxidation, membrane potential, intracellular redox homeostasis (intracellular ROS and H2O2, and antioxidant system (SOD, CAT and GSH)), intracellular ionic equilibrium (intracellular H+ and K+) and energy metabolism (mitochondrial membrane potential, intracellular Ca2+ and ATP level). The ROS analysis show that ·OH, 1O2, ·O2-and H2O2 were generated in this plasma-liquid interaction system and ·O2-served as the precursor of 1O2. Additionally, the solution pH was reduced. Plasma can effectively inactivate yeast cells mainly via apoptosis by damaging cell membrane, intracellular redox and ion homeostasis and energy metabolism as well as causing DNA fragmentation. ROS scavengers (l-His, d-Man and SOD) and pH buffer (phosphate buffer solution, PBS) were employed to investigate the role of five antimicrobial factors (·OH, 1O2, ·O2-, H2O2 and low pH) in plasma sterilization. Results show that they have different influences on the aforementioned cell physiological activities. The ·OH and 1O2 contributed most to the yeast inactivation. The ·OH mainly attacked cell membrane and increased cell membrane permeability. The disturb of cell energy metabolism was mainly attributed to 1O2. The damage of cell membrane as well as extracellular low pH could break the intracellular ionic equilibrium and further reduce cell membrane potential. The remarkable increase of intracellular H2O2 was mainly due to the influx of extracellular H2O2 via destroyed cell membrane, which played a little role in yeast inactivation during 10-min plasma treatment. These findings provide comprehensive insights into the antimicrobial mechanism of plasma, which can promote the development of plasma as an alternative water disinfection strategy.


Assuntos
Gases em Plasma , Desinfecção , Humanos , Peróxido de Hidrogênio , Viabilidade Microbiana , Plasma , Pressão , Espécies Reativas de Oxigênio , Água
8.
J Environ Manage ; 278(Pt 1): 111515, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33113396

RESUMO

The use of non-thermal plasma (NTP) generators in air processing systems and their duct networks to improve indoor air quality (IAQ) has grown considerably in recent years. This paper reviews the advantages and disadvantages of NTP generators for IAQ improvement in biological, chemical and particulate pollutant terms. Also, it assesses and compares the ability of a multipin corona discharge (MPCD) and a dielectric barrier discharge (DBD) generator to reduce the concentration of fine particulate matter (PM2.5) in recycled, unfiltered air in a refrigeration chamber. The MPCD generator was found to have a higher PM2.5 removal efficiency; also, it was faster in removing pollutants, used less energy, and produced much less ozone. The fact that the MPCD generator performed better was seemingly the result of its increased ion production mainly. NTP generators, however, cannot match air filtration media purifiers in this respect as the latter are much more effective in removing particles. Besides, NTP-based air purifying technology continues to be subject to a major drawback, namely: the formation of ozone as a by-product. In any case, the ozone generation was uncorrelated to ion emission when using different technologies.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Gases em Plasma , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Habitação , Tamanho da Partícula , Material Particulado/análise
9.
Food Chem ; 339: 128157, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33152897

RESUMO

The effects of water soluble antioxidant (ascorbic acid and EDTA), fat soluble antioxidant (α-tocopherol) and amphiphilic antioxidant (ascorbyl palmitate; AP) on the chemical physics and bioaccessibility of ß-carotene loaded nanoemulsions (CNE) were investigated. During accelerated storage at 45 °C for 15 days, AP showed the highest protective actions against particle size growth, color fading, lipid oxidation, and ß-carotene degradation in CNE (p < 0.05). CNE with AP was then subjected to treat with cold plasma (CP) induced reactive species system under various powers and contact times compared to control. AP was able to protect physical and oxidative stabilities of CNE as well as ß-carotene integrity. The highest in vitro lipid digestibility, bioaccessibility and ß-carotene stability were found in CNE with AP (p < 0.05). However, those properties were lowered after CP exposure. The results indicated that AP was a promising antioxidant in improving physical stability, oxidative stability, ß-carotene retention, and ß-carotene bioaccessibility of CNE.


Assuntos
Antioxidantes/química , Emulsões/química , Nanoestruturas/química , beta Caroteno/farmacocinética , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/química , Digestão , Ácido Edético/química , Emulsões/farmacocinética , Armazenamento de Alimentos , Oxirredução , Tamanho da Partícula , Gases em Plasma , Solubilidade , alfa-Tocoferol/química , beta Caroteno/química
10.
Chemosphere ; 262: 128336, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182148

RESUMO

Dielectric barrier discharge plasma and photocatalysis have been proposed as tools for decontamination of process water, especially in food industry. The present investigation aims to redefine and identify the features of coupling the two technologies in terms of degradation efficiency of a model compound. Results show that, when the process is carried out in plasma activated water in the presence of irradiated TiO2, the efficiency of the integrated process is lower than the sum of the two processes acting separately. It is proposed that afterglow species, e.g. hydrogen peroxide and/or peroxynitrites could be activated by UVA light irradiation producing hydroxyl radicals in the liquid phase. Even if TiO2 limits this additional effect by acting as UVA screen barrier material, its decontamination efficiency under certain conditions results higher than that obtained with plasma systems. These results open the route to chlorine-free decontamination processes and redefine the application framework of this integrated approach.


Assuntos
Indústria de Processamento de Alimentos/métodos , Gases em Plasma , Poluentes Químicos da Água/química , Purificação da Água/métodos , Catálise , Desenho de Equipamento , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Azul de Metileno/química , Processos Fotoquímicos , Titânio , Raios Ultravioleta , Purificação da Água/instrumentação
11.
Arch Biochem Biophys ; 698: 108726, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33326801

RESUMO

The study investigates the effect of LPDBD (Low Pressure Dielectric Barrier Discharge) (Ar + Air) plasma on seed germination, seedling growth and antioxidant enzyme activity of rice. Rice seeds were treated with LPDBD (Ar + Air) plasma for 2min, 4min, 6min, 8min and 10min. Seed germination rate, seedling growth, total chlorophyll content, enzymatic activity, total soluble sugar and protein concentration were increased in plants grown from the LPDBD (Ar + Air) plasma treated seeds. It was observed that the sprouting of seeds and the growth of seedlings of rice depends on the feed gases used to generate plasma and plasma processing time. In the case of plantlets germinated from the plasma-treated seeds of rice, the H2O2 level was increased significantly both in leaves and roots for 6min, 8min and 10min treatment respectively. No significant change was observed in Nitric Oxide (NO) concentration in seed, leaf, or root of plants grown from LPDBD (Ar + Air) plasma-treated seeds. The amount of total soluble sugar and protein increased significantly in the case of 2min, 4min, 6min, 8min and 10min seed treatment. Although plants exhibited no significant increase in APX activities, but a significant increase of CAT and SOD activity in the leaf and root was found. This study reveals that LPDBD (Ar + Air) plasma is involved in the elevation of ROS species in leaf and root of rice plants which is tightly regulated by the upregulation of CAT activity that ultimately enhances the seed germination and growth of rice plantlets.


Assuntos
Catalase/metabolismo , Oryza/metabolismo , Gases em Plasma/farmacologia , Plântula/metabolismo , Sementes/metabolismo , Superóxido Dismutase/metabolismo , Ar , Argônio/química , Germinação/efeitos dos fármacos , Germinação/fisiologia , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento
12.
Food Chem ; 340: 128198, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33032147

RESUMO

In this study, potential of dielectric-barrier discharge (DBD) plasma treatment (40 kV, 12 kHz at 1, 2, 3 and 4 min) to eliminate soybean agglutinin (SBA) activity was investigated in a SBA model system and soymilk. The plasma treatment decreased the SBA in the model system and hemagglutination activity was decreased by 87.31%. SDS-PAGE analysis confirmed the degradation of the SBA polypeptide chain. The multi-spectroscopic analysis revealed a two-stage structure alteration in the SBA upon exposure to the plasma treatment. Oxidation of NH-/NH2- at the peptide bond disrupted the hydrogen bonds and altered the secondary structure of SBA. Further oxidation of aromatic amino acid, cleavage of peptide bonds and the breakage of polypeptide led to the SBA fragmentation and complete unfolding of the protein. The SBA inactivation by the plasma treatment was confirmed in soymilk. Plasma treatment is a promising technology for the elimination of SBA in soybean product.


Assuntos
Lectinas de Plantas/química , Gases em Plasma/química , Proteínas de Soja/química , Impedância Elétrica , Ligação de Hidrogênio , Oxirredução , Estrutura Secundária de Proteína , Leite de Soja/química
13.
Food Chem ; 336: 127635, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32763734

RESUMO

A one-step, highly-efficiency, and low-cost cold atmospheric pressure plasma (CAPP)-based method for obtaining safe-to-consume beetroot juice (BRJ) with enhanced nutritional quality is presented. Three reaction-discharge systems with different CAPPs were studied to check how the composition and physicochemical properties changed during CAPP treatment of BRJ. To identify reactive species occur in gas phase of applied CAPP for BRJ treatment, optical emission spectrometry was used. Finally, the cytotoxicity of so-obtained BRJ to human epithelial colorectal adenocarcinoma (Caco-2) and human non-malignant intestine microvascular endothelial cells (HIMEC) was assessed. Based on the performed analyses it was found that controlled CAPP treatment of BRJ changes the fraction pattern of elements in addition to increase the content of phenolic compound presents in BRJ. Furthermore, the defined CAPP treatment of BRJ inhibits proliferation of Caco-2 cell lines, exhibiting non-cytotoxic effect for HIMEC non-malignant endothelial cells. As a result, safe-to-consume BRJ of improved nutritional quality was produced.


Assuntos
Beta vulgaris/química , Indústria de Processamento de Alimentos/métodos , Sucos de Frutas e Vegetais , Gases em Plasma , Antioxidantes/química , Pressão Atmosférica , Células CACO-2 , Carboidratos/análise , Células Endoteliais/efeitos dos fármacos , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/toxicidade , Humanos , Metais/análise , Valor Nutritivo , Fenóis/análise , Testes de Toxicidade
14.
Food Chem ; 338: 127826, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32810815

RESUMO

This study aimed to evaluate the mutagenicity and oral acute toxicity of winter mushroom powder (PW) treated by atmospheric non-thermal plasma (ANP). Winter mushroom powder without plasma treatment (CW) containing an equivalent amount of sodium nitrite as PW was used as a control. The Ames test revealed that the number of revertant colonies did not significantly increase compared to that in the control. Acute toxicity was assessed in rats that were fed a single dose of winter mushroom powder (5000 mg/kg body weight). Results of the acute toxicity test revealed no remarkable clinical symptoms in any of the rats. No significant difference was observed in of the serum biochemical parameters between the treatments. Regardless of the ANP treatment, mild histological changes were observed in few rats in all groups. Therefore, it is concluded that ANP treatment did not cause any mutagenicity or acute toxicity in the winter mushroom.


Assuntos
Flammulina/química , Indústria de Processamento de Alimentos/métodos , Pós/toxicidade , Administração Oral , Animais , Masculino , Testes de Mutagenicidade , Gases em Plasma , Pós/administração & dosagem , Pós/química , Ratos Sprague-Dawley , Testes de Toxicidade Aguda
15.
Int J Food Microbiol ; 337: 108948, 2021 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-33197682

RESUMO

Novel processing methods such as cold atmospheric plasma (CAP) and natural antimicrobials like nisin, are of interest to replace traditional food decontamination approaches as, due to their mild nature, they can maintain desirable food characteristics, i.e., taste, texture, and nutritional content. However, the microbial growth characteristics (planktonic growth/surface colonies) and/or the food structure itself (liquid/solid surface) can impact the inactivation efficacy of these novel processing methods. More specifically, cells grown as colonies on a solid(like) surface experience a completely different growth environment to cells grown planktonically in liquid, and thus could display a different response to novel processing treatments through stress adaptation and/or cross protection mechanisms. The order in which combined treatments are applied could also impact their efficacy, especially if the mechanisms of action are complementary. This work presents a fundamental study on the efficacy of CAP and nisin, alone and combined, as affected by food system structure. More specifically, Listeria innocua was grown planktonically (liquid broth) or on a viscoelastic Xanthan gum gel system (1.5% w/v) and treated with CAP, nisin, or a combination of the two. Both the inactivation system, i.e., liquid versus solid(like) surface and the growth characteristics, i.e., planktonic versus colony growth, were shown to impact the treatment efficacy. The combination of nisin and CAP was more effective than individual treatments, but only when nisin was applied before the CAP treatment. This study provides insight into the environmental stress response/adaptation of L. innocua grown on structured systems in response to natural antimicrobials and novel processing technologies, and is a step towards the faster delivery of these food decontamination methods from the bench to the food industry.


Assuntos
Antibacterianos/farmacologia , Manipulação de Alimentos/métodos , Listeria/efeitos dos fármacos , Nisina/farmacologia , Gases em Plasma/farmacologia , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Listeria/crescimento & desenvolvimento , Modelos Biológicos , Pasteurização/métodos
16.
PLoS One ; 15(12): e0243965, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33326504

RESUMO

The response to the COVID-19 epidemic is generating severe shortages of personal protective equipment around the world. In particular, the supply of N95 respirator masks has become severely depleted, with supplies having to be rationed and health care workers having to use masks for prolonged periods in many countries. We sought to test the ability of 7 different decontamination methods: autoclave treatment, ethylene oxide gassing (ETO), low temperature hydrogen peroxide gas plasma (LT-HPGP) treatment, vaporous hydrogen peroxide (VHP) exposure, peracetic acid dry fogging (PAF), ultraviolet C irradiation (UVCI) and moist heat (MH) treatment to decontaminate a variety of different N95 masks following experimental contamination with SARS-CoV-2 or vesicular stomatitis virus as a surrogate. In addition, we sought to determine whether masks would tolerate repeated cycles of decontamination while maintaining structural and functional integrity. All methods except for UVCI were effective in total elimination of viable virus from treated masks. We found that all respirator masks tolerated at least one cycle of all treatment modalities without structural or functional deterioration as assessed by fit testing; filtration efficiency testing results were mostly similar except that a single cycle of LT-HPGP was associated with failures in 3 of 6 masks assessed. VHP, PAF, UVCI, and MH were associated with preserved mask integrity to a minimum of 10 cycles by both fit and filtration testing. A similar result was shown with ethylene oxide gassing to the maximum 3 cycles tested. Pleated, layered non-woven fabric N95 masks retained integrity in fit testing for at least 10 cycles of autoclaving but the molded N95 masks failed after 1 cycle; filtration testing however was intact to 5 cycles for all masks. The successful application of autoclaving for layered, pleated masks may be of particular use to institutions globally due to the virtually universal accessibility of autoclaves in health care settings. Given the ability to modify widely available heating cabinets on hospital wards in well-resourced settings, the application of moist heat may allow local processing of N95 masks.


Assuntos
Descontaminação/métodos , Reutilização de Equipamento , /virologia , /patologia , Óxido de Etileno/farmacologia , Humanos , Peróxido de Hidrogênio/farmacologia , Ácido Peracético/farmacologia , Gases em Plasma/farmacologia , /isolamento & purificação , Raios Ultravioleta , Vesiculovirus/efeitos dos fármacos , Vesiculovirus/efeitos da radiação
17.
Int J Food Microbiol ; 335: 108889, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33007604

RESUMO

The safety and quality of cereal grain supplies are adversely impacted by microbiological contamination, with novel interventions required to maximise whole grains safety and stability. The microbiological contaminants of wheat grains and the efficacy of Atmospheric Cold Plasma (ACP) for potential to control these risks were investigated. The evaluations were performed using a contained reactor dielectric barrier discharge (DBD) system; samples were treated for 0-20 min using direct and indirect plasma exposure. Amplicon-based metagenomic analysis using bacterial 16S rRNA gene and fungal 18S rRNA gene with internal transcribed spacer (ITS) region was performed to characterize the change in microbial community composition in response to ACP treatment. The antimicrobial efficacy of ACP against a range of bacterial and fungal contaminants of wheat, was assessed to include individual isolates from grains as challenge pathogens. ACP influenced wheat microbiome composition, with a higher microbial diversity as well as abundance found on the untreated control grain samples. Culture and genomic approaches revealed different trends for mycoflora detection and control. A challenge study demonstrated that using direct mode of plasma exposure with 20 min of treatment significantly reduced the concentration of all pathogens. Overall, reduction levels for B. atrophaeus vegetative cells were higher than for all fungal species tested, whereas B. atrophaeus spores were the most resistant to ACP among all microorganisms tested. Of note, repeating sub-lethal plasma treatment did not induce resistance to ACP in either B. atrophaeus or A. flavus spores. ACP process control could be tailored to address diverse microbiological risks for grain stability and safety.


Assuntos
Anti-Infecciosos/farmacologia , Resistência Microbiana a Medicamentos , Microbiota/efeitos dos fármacos , Gases em Plasma/farmacologia , Triticum/microbiologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Grão Comestível/microbiologia , Fungos/classificação , Fungos/efeitos dos fármacos , Fungos/genética , Fungos/isolamento & purificação , RNA Ribossômico/genética , Especificidade da Espécie
18.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(5): 566-570, 2020 Oct 01.
Artigo em Chinês | MEDLINE | ID: mdl-33085243

RESUMO

The application of cold atmospheric plasma to titanium surface modification has recently become a research focus in the area of material modification. Previous studies found that cold atmospheric plasma can affect the colonization of bacteria and biological behaviors of osteoblasts by changing the surface characteristics of titanium in vitro. In vivo studies reveal that cold atmospheric plasma can promote the process of osseointegration of titanium implants. This review focuses on research on the effects of the surface modification of titanium implants with cold atmospheric plasma on osseointegration.


Assuntos
Implantes Dentários , Gases em Plasma , Osseointegração , Osteoblastos , Titânio
19.
Anticancer Res ; 40(11): 6205-6212, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33109557

RESUMO

BACKGROUND/AIM: Mammary carcinoma (MC) remains one of the leading causes of morbidity and mortality in the female population worldwide. Cold physical plasma at atmospheric pressure (CAP) has an antioncogenic effect on tumor cells, and its anticancer properties may complement or even extend existing treatment options. In the present study, the efficacy of CAP was characterized on an MC in vitro cell culture system. MATERIALS AND METHODS: MC cells (MCF-7, MDA-MB-231) were directly treated with CAP or incubated with CAP-treated cell culture medium. Cell growth, cell mobility and apoptosis were subsequently analyzed. RESULTS: A single treatment of MC cells with CAP and CAP treated medium led to a treatment-time dependent reduction of cell growth. Furthermore, CAP exposure led to a loss of cellular motility and induced apoptosis. CONCLUSION: Due to its anticancer properties, CAP treatment is an innovative and promising physical approach to expand and complement the treatment options for MC. In particular, a combination of CAP application with surgical and/or chemotherapeutic interventions might significantly improve the therapeutic outcomes.


Assuntos
Argônio/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Gases em Plasma/uso terapêutico , Argônio/farmacologia , Pressão Atmosférica , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Cinética , Gases em Plasma/farmacologia
20.
Crit Rev Food Sci Nutr ; 60(16): 2676-2690, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32876477

RESUMO

In recent years, applications of cold plasma treatments have shown high efficiency in sterilization of fresh fruit and vegetables. With encouraging results, development of this technique focuses on influences of cold plasma on the quality attributes of these fresh produce. More studies found that the quality attributes are maintained in an acceptable range or can even be improved under certain plasma treatment conditions. This review provides an overview of the multiple effects of cold plasma on the fresh produce, in terms of physical, chemical and physiological aspects. Besides, the possible mechanisms of how plasma influences these quality attributes is elaborated, which is useful for further modification and improvement of the plasma technology, so that quality enhancement and shelf life extension can be achieved. Future trends in the development of cold plasma technology are also presented. Cold plasma treatment is a potential technology for treating fresh fruit and vegetables to enhance their quality and extend their shelf life. However, knowledge of the effects of cold plasma on the quality changes of fresh fruit and vegetables is still limited. Therefore, there is a need for future studies to understand the mechanisms of plasma effects on controlling the interactions between plasma and food products in order to realize the early adoption of the technology to the food industry.


Assuntos
Conservação de Alimentos , Frutas , Gases em Plasma , Verduras , Frutas/química , Frutas/fisiologia , Esterilização , Verduras/química , Verduras/fisiologia
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