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1.
Molecules ; 26(1)2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33375142

RESUMO

This work evaluated the application of organic acids (acetic and peracetic acid) and ultrasound as alternative sanitization methods for improving the microbiological and physicochemical qualities of strawberries. A reduction of up to 2.48 log CFU/g aerobic mesophiles and between 0.89 and 1.45 log CFU/g coliforms at 35 °C was found. For molds and yeasts, significant differences occurred with different treatments and storage time (p < 0.05). Ultrasound treatments in combination with peracetic acid and acetic acid allowed a decimal reduction in molds and yeasts (p < 0.05). All evaluated treatments promoted a significant reduction in the Escherichia coli count (p < 0.05). Scanning electron microscopy revealed fragmented E. coli cells due to treatment with acetic acid and ultrasound. Storage time significantly affected pH, total titratable acidity, total soluble solids and the ratio of the total titratable acidity to the total soluble solids (p < 0.05). Anthocyanin content did not change with treatment or time and generally averaged 13.47 mg anthocyanin/100 g of strawberries on fresh matter. Mass loss was not significantly affected by the applied treatments (p > 0.05). The combination of ultrasound and peracetic acid may be an alternative to chlorine-based compounds to ensure microbiological safety without causing significant changes in the physicochemical characteristics of strawberries.


Assuntos
Ácido Acético/química , Desinfecção , Microbiologia de Alimentos , Fragaria , Ácido Peracético/química , Ondas Ultrassônicas , Ácido Acético/farmacologia , Fenômenos Químicos , Desinfetantes/química , Desinfetantes/farmacologia , Desinfecção/métodos , Microbiologia de Alimentos/métodos , Qualidade dos Alimentos , Fragaria/microbiologia , Microbiota , Ácido Peracético/farmacologia
2.
Biomed Instrum Technol ; 54(6): 397-409, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33339032

RESUMO

Standard methods are needed to reliably and efficiently assess bacterial contamination of processed medical devices. This article demonstrates a standard operating procedure (SOP) for fluorescence microscopy-based detection of residual bacteria on medical devices (BAC-VIS). BAC-VIS uses a 4',6-diamidino-2-phenylindole (DAPI) stain with fluorescent microscopy to quickly and cost-effectively detect bacterial contamination of processed medical device parts. The BAC-VIS protocol was optimized and achieved greater than 80% staining efficiency and a signal-to-noise ratio of more than 20 using four representative organisms. The SOP was first validated for use on a buildup biofilm model, accessory channels of contaminated clinically used devices, and inoculated endoscope end caps and O-rings. The buildup biofilm model was used to evaluate BAC-VIS after repeated treatment of adherent bacteria with three common high-level disinfectants: glutaraldehyde, ortho-phthalaldehyde, and peracetic acid. Next, BAC-VIS was used to assess clinically used endoscope parts that cultured positive for Gram-negative bacteria. DAPI-stained cells were found on all culture-positive devices, especially in grooves and imperfections on the surface. Finally, BAC-VIS was used to detect bacteria on inoculated endoscope device components. The results showed potential for BAC-VIS to be a valuable tool for industry and academic/medical researchers for investigations of contaminated medical devices. Results obtained using BAC-VIS can increase understanding of the role of design in cleanability, wear, and prevention of contamination and may lead to improvements in materials and design that could make processed endoscope use safer for patients. Of note, this protocol is not for detecting bacteria on scopes or scope parts that will be put back into clinical use.


Assuntos
Desinfetantes , Bactérias , Contaminação de Equipamentos/prevenção & controle , Humanos , Microscopia de Fluorescência/métodos , Ácido Peracético/química
3.
Chemosphere ; 257: 127229, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32505952

RESUMO

With low potential to generate harmful by-products, peracetic acid (PAA) has drawn increasing attention as an alternative oxidant for disinfection and advanced oxidation processes in wastewater treatment. Commercial formulations contain significant concentrations of both PAA and H2O2 in aqueous solutions and a robust method to distinctively quantify the two respective oxidants simultaneously is needed. This study aimed to improve the accuracy of employing methyl p-tolyl sulfide (MTS) and triphenylphosphine (TPP) as indicators for PAA and H2O2, respectively, under various environmental conditions, by the detection of the oxidation products of sulfoxide MTSO and phosphine oxide TPPO using HPLC-UV. To improve the analytical method, the reaction rates of MTS and TPP with PAA and H2O2, impact of pH on the detection, and matrix effects of real wastewater effluents and produce wash water were evaluated to minimize the interference of H2O2 with PAA determination. The determined rate constants of PAA reaction with MTS (kPAA/MTS=34.6±0.4M-1s-1 in 2/1 H2O/acetonitrile (ACN) (v/v)) and H2O2 reaction with TPP ( [Formula: see text] in 1/1 H2O/ACN (v/v)) provided the fundamental guidance to optimize the method. Overall, a highly accurate and sensitive method for simultaneous quantification of PAA and H2O2 (method quantification limit = 0.8 and 6.0 µM, respectively) is established and will be useful for various environmental samples with PAA and H2O2 applications.


Assuntos
Ácido Peracético/química , Purificação da Água/métodos , Cromatografia Líquida de Alta Pressão , Desinfecção/métodos , Peróxido de Hidrogênio , Oxidantes , Oxirredução , Águas Residuárias , Água
4.
J Environ Sci (China) ; 89: 1-8, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31892382

RESUMO

Increasing concerns have been raised on endocrine disrupting chemicals like the sex hormone 17α-ethinylestradiol (EE2), the more since traditional wastewater (WW) treatments appear to be ineffective for their removal. The efficacy of the relatively novel disinfectant peracetic acid (PAA) in EE2 removal was evaluated, as well as its potential effects on WW quality parameters. The treatments tested for EE2 removal were also evaluated in terms of toxicity, through the determination of biochemical responses (antioxidant enzymes, lipid peroxidation and vitellogenin induction) using zebrafish (Danio rerio) as a biological model. PAA contact times less than 20 min appeared insufficient regardless of the PAA dose tested, but a 100% EE2 removal was attained at a PAA concentration of 15 mg/L with a contact time of 20 min. Total suspended solids, chemical oxygen demand and pH in PAA treatments remained well within levels set in European legislation for WW discharge. EE2 induced significant increased vitellogenin (VTG) levels in both female and male fish, indicating increased estrogenic activity, especially in males suggesting an endocrine disruption effect. With the addition of PAA (15 mg/L), however, VTG levels in both sexes returned to control values. Although this PAA treatment showed increased levels of the antioxidant enzyme catalase, the lipid peroxidation levels were similar or even lower than in controls. Overall the results suggest that the use of PAA appears a promising way forward as a less toxic alternative to chlorine disinfection with high efficiency in the removal of EDC like EE2.


Assuntos
Etinilestradiol/química , Ácido Peracético/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias , Poluentes Químicos da Água/química , Anticoncepcionais , Estradiol , Etinilestradiol/análise , Ácido Peracético/análise , Vitelogeninas , Poluentes Químicos da Água/análise
5.
Environ Monit Assess ; 192(2): 114, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31940101

RESUMO

17ß-Estradiol (E2) is a natural estrogen produced by the feminine endocrine system. It is excreted mainly through urine and feces. Exposure to E2 may affect the reproductive system of both animals and humans, especially since the removal of E2 in conventional processes and technologies present in the wastewater treatment plants is not sufficient. Chlorine is one of the most studied and used oxidant worldwide. Although there are studies that demonstrate the endocrine disrupting compounds removal like E2, its reaction with organic matter can originate by-products, namely, trihalomethanes, which are known to have high toxic potential. The main aim of the present study was to evaluate the removal of E2 (50 µg E2 L-1-maximum concentration) using peracetic acid (PAA), a seeming cleaner and innocuous alternative to chlorine. To this end, a series of jar tests were performed, using different peracetic acid concentrations (1, 5, 10, and 15 mg L-1) and contact times (10, 15, and 20 min). The results obtained showed that a peracetic acid concentration of 15 mg L-1 with a contact time of 20 min had a removal efficacy of approximately 100%. The second main goal of this study was to evaluate the ecotoxicological potential of the tested treatments on the zebrafish Danio rerio. Several oxidative stress biomarkers were evaluated, namely glutathione S-transferase, lipid peroxidation, and catalase, besides vitellogenin. Both peracetic acid and E2 caused significant increases in the oxidative stress biomarkers, although this did not lead to increased lipid peroxidation levels. In addition, peracetic acid significantly decreased the estrogenic activity of E2, as indicated by decreased vitellogenin levels. Peracetic acid demonstrated to have great potential as an alternative disinfectant for chlorine treatments, and indications for future research are discussed.


Assuntos
Monitoramento Ambiental , Estrogênios/análise , Ácido Peracético/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Animais , Cloro , Desinfetantes , Disruptores Endócrinos/análise , Estradiol/análise , Estrona , Humanos , Trialometanos , Vitelogeninas , Águas Residuárias
6.
Biochim Biophys Acta Proteins Proteom ; 1868(2): 140334, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31786473

RESUMO

Aseptic processing and terminal sterilization become increasingly challenging as medical devices become more complex and include active biologics. Terminal sterilization is preferred for patient safety and production costs. We aimed to determine how sterilization using supercritical CO2 (scCO2) with low levels of peracetic acid (PAA) affects amino acids and human epidermal growth factor (EGF) as a model protein. In a benchtop reactivity test, the amino acids methionine, tryptophan, arginine and lysine reacted with low levels of PAA in solution. At PAA levels used for scCO2 sterilization, however, mass spectrometry only identified oxidative adducts on methionine and tryptophan. Mass spectrometry analysis of EGF exposed to scCO2/PAA identified oxidative adducts on residues Met21, Trp49 and Trp50, as well as a low level of truncations after residues Trp49 and Trp50. Importantly, processing of EGF in solution with scCO2 did not affect its native conformation, and sterilized EGF maintained its activity in cell proliferation assays. When processing samples in lyophilized form with scCO2/PAA, amino acids did not react with PAA and the presence of adducts was strongly reduced on methionine and tryptophan, both as single amino acids and in EGF. Truncation after tryptophan residues did not occur. EGF sterilized in the lyophilized form retained its activity when processing occurred with added moisture. These results have significant implications for the maintenance of biological function in sterilized decellularized scaffolds and the ability to manufacture terminally sterilized combination devices containing therapeutic peptides or proteins.


Assuntos
Dióxido de Carbono/química , Fator de Crescimento Epidérmico/química , Ácido Peracético/química , Esterilização , Células 3T3 , Animais , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Fator de Crescimento Epidérmico/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Humanos , Espectrometria de Massas , Metionina/análise , Metionina/química , Camundongos , Oxirredução , Triptofano/análise , Triptofano/química
7.
Braz Oral Res ; 33: e057, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31365704

RESUMO

The aim of this study was to evaluate the effect of peracetic acid (PAA) as a single irrigant on the smear layer, on the intraradicular dentinal bond strength, and on the penetrability of an epoxy-based resin sealer into the dentinal tubules. A total of 120 roots were distributed into 4 groups according to the irrigant used in root canal preparation: 1% PAA (PAA); 2.5% NaOCl followed by final irrigation with 17% EDTA and 2.5% NaOCl (NaOCl-EDTA-NaOCl); 2.5% NaOCl (NaOCl); and saline solution (SS). The smear layer was evaluated using scanning electron microscopy. The bond strength of an epoxy-based resin sealer (AH Plus) to root dentin was evaluated by the push-out test and penetrability of the sealer into dentinal tubules was observed by confocal laser microscopy. The results were analyzed by the Kruskal-Wallis and the Dunn post-test (α = 0.05). The use of 1% PAA as single root canal irrigant provided smear layer removal and improved the penetrability and bond strength of AH Plus to root dentin in a manner similar to that of the NaOCl-EDTA-NaOCl group (p > 0.05). The NaOCl and SS groups had higher values of smear layer and lower values of sealer penetrability and dentin bond strength than the PAA and NaOCl-EDTA-NaOCl groups (p < 0.05). Thus, 1% PAA has the potential to be used as a single irrigant in root canals.


Assuntos
Cavidade Pulpar/efeitos dos fármacos , Dentina/efeitos dos fármacos , Resinas Epóxi/química , Ácido Peracético/química , Materiais Restauradores do Canal Radicular/química , Irrigantes do Canal Radicular/química , Camada de Esfregaço/química , Colagem Dentária/métodos , Cavidade Pulpar/química , Dentina/química , Ácido Edético/química , Humanos , Teste de Materiais , Microscopia Confocal , Microscopia Eletrônica de Varredura , Valores de Referência , Reprodutibilidade dos Testes , Hipoclorito de Sódio/química
8.
Int J Biol Macromol ; 133: 382-390, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31002909

RESUMO

Keratin has been attracting interest due to its stability against enzymatic degradation thereby allowing more predictable degradation profile for tissue regeneration applications. While the efficacy of keratin has been demonstrated in different tissue models, there has been no systematic study to investigate and compare the different routes of keratin extraction from human hair. Here, we compared the four commonly used extraction methods and highlighted both physical and chemical differences in the extracted keratin. Keratin was extracted from human hair using one of four common agents, namely, sodium sulfide, peracetic acid, urea and thioglycolic acid. Whereas no specific trend was observed, the keratin extracted through peracetic acid method had significantly different properties. It resulted in lowest yield of 52 µg/mL and low crystallinity but the protein formed aggregates with highest hydrodynamic average size of around 283 nm compared to the other three methods. However, despite greater aggregation, keratin extracted from peracetic acid method exhibited secondary structural conformation similar to thioglycolic acid method. All the four extracted keratin promoted cellular proliferation of osteoblasts compared to the uncoated surface. These results provide new insight into the extraction of keratin from human hair with implications for its use as a biomaterial.


Assuntos
Fracionamento Químico/métodos , Cabelo/química , Queratinas/isolamento & purificação , Humanos , Queratinas/química , Tamanho da Partícula , Ácido Peracético/química , Estrutura Secundária de Proteína , Tioglicolatos/química
9.
Int J Biol Macromol ; 125: 1008-1015, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30572050

RESUMO

Water soluble keratose proteins were obtained from an Ovis Aries wool using peracetic acid oxidation. The wool samples and the extracted keratose proteins were characterized by using FTIR, XRD, SEM and TGA techniques. Fractions of α-keratose (MW = 43-53 kDa) along with protein species with molecular weights between 23 kDa and 33 kDa were identified in the SDS-PAGE analysis result of the extracted protein mixture. DLS and AFM experiments indicated that self-assembled globular nanoparticles with diameters between 15 nm and 100 nm formed at 5 mg/ml keratose concentration. On the other hand, upon incubation of 10 w % keratose solutions at 37 °C and 50 °C, interconnected keratose hydrogels with respective storage modulus (G') values of 0.17 ±â€¯0.03 kPa and 3.7 ±â€¯0.5 kPa were obtained. It was shown that the keratose hydrogel prepared at 37 °C supported L929 mouse fibroblast cell proliferation which suggested that these keratose hydrogels could be promising candidates in soft tissue engineering applications.


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Queratinas/isolamento & purificação , Nanopartículas/química , Tecidos Suporte , Fibra de Lã/análise , Animais , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Hidrogéis/farmacologia , Queratinas/farmacologia , Queratinas/ultraestrutura , Camundongos , Peso Molecular , Nanopartículas/ultraestrutura , Oxirredução , Tamanho da Partícula , Ácido Peracético/química , Carneiro Doméstico , Engenharia Tecidual/métodos
10.
Poult Sci ; 98(1): 393-397, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30125007

RESUMO

In 2016, USDA-Food Safety and Inspection Service began using a neutralizing buffered peptone water (nBPW) to rinse broiler carcasses for Salmonella and Campylobacter performance standard testing. The nBPW contains standard buffered peptone water (BPW) with compounds to neutralize residual antimicrobials that may be transferred from the carcass to the sample rinsate. However, a direct comparison of nBPW and BPW on carcasses commercially treated with antimicrobials has not been conducted. On 3 replicate days in a commercial broiler processing plant, an immersion chilling biomap using whole carcass rinse samples taken prior to any chilling treatment (30), after pre-chill treatment (30), after primary chill (30), after secondary chill (30), after post-chill treatment (50), and after post-chill treatment without the pre-chill treatment (49) were tested. Carcasses were rinsed with either BPW (without neutralizer) or nBPW. Rinsates were sampled for Salmonella and Campylobacter prevalence and both Enterobacteriaceae (EB) prevalence and counts. No significant differences were observed between sampling sites or rinse media for Salmonella due to an overall low prevalence (4 positive/219 samples). Campylobacter prevalence significantly decreased from prior to chilling (93%) to after all chilling steps (47%) as anticipated (P < 0.0001); however, overall significantly fewer Campylobacter positive carcasses were detected when nBPW was used (55%) in comparison to BPW (70%, P = 0.0258). Both EB prevalence and counts significantly decreased (both P < 0.0001) from prior to chilling (100%, 2.35 log10 CFU/mL) through after all chilling steps (52%, 0.47 log10 CFU/mL). The use of nBPW versus BPW did not impact EB prevalence; however, samples rinsed with nBPW had significantly higher overall counts (1.26 vs. 1.00 log10 CFU/mL, P = 0.0134). The results from this study indicate that the use of a PAA pre-chill treatment did not significantly impact bacteria recovery following all chilling steps. The use of nBPW was effective in neutralizing residual PAA in carcass rinsates when sampling for EB counts; however, nBPW may lessen the ability to detect Campylobacter in these same samples.


Assuntos
Campylobacter/isolamento & purificação , Enterobacteriaceae/isolamento & purificação , Manipulação de Alimentos/métodos , Microbiologia de Alimentos/métodos , Salmonella/isolamento & purificação , Animais , Anti-Infecciosos/química , Tampões (Química) , Galinhas , Carne/microbiologia , Peptonas/química , Ácido Peracético/química , Água
11.
Food Environ Virol ; 11(1): 76-89, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30430442

RESUMO

With increasing interest in peracetic acid (PAA) as a disinfectant in water treatment processes, this study determined PAA treatment effects on human noroviruses (hNoVs) genotype I (GI) and genotype II (GII) as well as effects on bacteriophage MS2 and murine norovirus (MNV) in relation to pH. Across all pH conditions, PAA achieved between 0.2 and 2.5 log10 reduction of hNoVs over 120 min contact time in buffer solution as measured by reverse transcription-qPCR (RT-qPCR). The PAA treatments produced similar RT-qPCR reductions of MS2 and MNV, in the range of 0.2-2.7 log10. Infectivity assays achieved > 4 log10 reduction of both MS2 and MNV in buffer solution after 120 min contact time. Comparing PAA activity across varying pH, disinfection at pH 8.5, in general, resulted in less reduction of infectivity and molecular signals compared to pH conditions of 6.5 and 7.5. This difference was most pronounced for reductions in infectivity of MNV and MS2, with as much as 2.7 log10 less reduction at pH 8.5 relative to lower pH conditions. This study revealed that PAA was an effective disinfectant for treatment of hNoV GI and GII, MS2 and MNV, with greatest virus reduction observed for MS2 and MNV infectivity. RT-qPCR reductions of MS2 and MNV were lower than concurrent MS2 and MNV infectivity reductions, suggesting that observed hNoV RT-qPCR reductions may underestimate reductions in hNoV infectivity achieved by PAA. Although virus disinfection by PAA occurred at all evaluated pH levels, PAA is most effective at pH 6.5-7.5.


Assuntos
Infecções por Caliciviridae/virologia , Norovirus/efeitos dos fármacos , Ácido Peracético , Desinfetantes/química , Desinfetantes/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Norovirus/genética , Norovirus/patogenicidade , Ácido Peracético/química , Ácido Peracético/farmacologia , RNA Viral/análise , RNA Viral/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacos
12.
Chemosphere ; 213: 25-40, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30212717

RESUMO

Peracetic acid (PAA) has gained increasing attention over the last decades as a suitable and environmentally-friendly alternative to chlorine-based compounds for wastewater disinfection, claiming limited disinfection by-products (DBPs) formed and no persistent residues in the environment. The present work aims at presenting a comprehensive and updated review of the ecotoxicological effects of effluents treated with PAA, to be ascribed to residual PAA and hydrogen peroxide (H2O2) and DBP formation. Modest concentrations of DBPs have been observed after PAA treatment, mainly carboxylic acids, which are not recognized as genotoxic. Moreover, there is no evidence of any endocrine disruption potential of PAA in human health or in the ecotoxicological studies. The associated H2O2 fraction can potentially minimize the formation of halogenated DBPs and also contribute to the acute toxic effects of treated effluents. Effluents disinfected with PAA at concentrations typical of the wastewater treatment field have displayed limited toxic, mutagenic and genotoxic effects on different aquatic organisms, particularly low compared to chlorine-based disinfectants.


Assuntos
Desinfecção/métodos , Ecotoxicologia/métodos , Ácido Peracético/química , Humanos
13.
Korean J Gastroenterol ; 71(6): 319-323, 2018 Jun 25.
Artigo em Coreano | MEDLINE | ID: mdl-29943558

RESUMO

Background/Aims: We aimed to investigate the efficacy of peracetic acid (EndoPA® Firson Co., Ltd., Cheonan, Korea) in disinfecting endoscopes. Methods: We prospectively investigated the gastroscopes (Part I) utilized in 100 gastroscopic examinations and colonoscopes (Part II) utilized in 30 colonoscopic examinations after disinfecting them with 0.2% peracetic acid (EndoPA® Firson Co., Ltd.). These instruments had been collected consecutively throughout the study period. We reprocessed and disinfected the endoscopes according to the guidelines for cleaning and disinfecting gastrointestinal endoscopes laid down by the Korean Society of Gastrointestinal Endoscopy in 2017. Three culture samples were obtained from each examination, based on different sampling methods. The primary outcome was a positive culture rate. Results: In Part I of our study, two of 300 samples were positive. The culture positive rate after disinfection was 0.7% (2/300). The culture positive rate was not significantly different based on the exposure time to EndoPA® or the age of the scopes (p=0.7 or 0.2, respectively). In Part II of our study, all samples (n=90) were negative. Conclusions: We conclude that 0.2% peracetic acid (EndoPA®) appears to be a good disinfectant for both gastroscopes and colonoscopes.


Assuntos
Desinfetantes/farmacologia , Endoscópios Gastrointestinais/microbiologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Ácido Peracético/farmacologia , Desinfetantes/química , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/crescimento & desenvolvimento , Bactérias Gram-Positivas/isolamento & purificação , Ácido Peracético/química , Estudos Prospectivos
14.
Meat Sci ; 143: 69-73, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29715662

RESUMO

"Blown pack" spoilage is primarily caused by Clostridium estertheticum. The primary source of contamination is probably pelts, faeces and soil during opening cuts and de-hiding. Peroxyacetic acid (POAA) based fogs are commonly included in an abattoir's routine cleaning process. Hydrogen peroxide (H2O2) is a powerful oxidizing agent that penetrates microbe cell walls causing cell death. In this study, we compared the ability of H2O2 and OXYSAN ZS (POAA containing 1-hydroxyethylidine-1,1-diphosphonic acid as a stabilizer) in different formats to inactivate C. estertheticum spores. Hydrogen peroxide treatment using Phytagel™ gel as carrier was effective on fleece against both naturally contaminating microflora and C. estertheticum spores. This is the first time an antimicrobial treatment has been shown to inactivate C. estertheticum spores on such a complex and highly contaminated matrix. Both H2O2 and OXYSAN ZS treatments inactivated C. estertheticum spores on stainless steel indicating their potential use as an in-plant decontamination procedure or inclusion in routine in-process cleaning.


Assuntos
Antibacterianos/farmacologia , Clostridium/efeitos dos fármacos , Desinfetantes/farmacologia , Peróxido de Hidrogênio/farmacologia , Ácido Peracético/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Matadouros , Pelo Animal/efeitos dos fármacos , Pelo Animal/microbiologia , Animais , Antibacterianos/química , Carga Bacteriana/efeitos dos fármacos , Clostridium/crescimento & desenvolvimento , Clostridium/fisiologia , Desinfetantes/química , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Géis , Peróxido de Hidrogênio/química , Indústria de Embalagem de Carne/métodos , Viabilidade Microbiana/efeitos dos fármacos , Nova Zelândia , Ácido Peracético/química , Carneiro Doméstico , Esporos Bacterianos/crescimento & desenvolvimento , Esporos Bacterianos/fisiologia , Aço Inoxidável , Volatilização
15.
Biomacromolecules ; 19(7): 3020-3029, 2018 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-29757614

RESUMO

To expand the use of renewable materials, paper products with superior mechanical and optical properties are needed. Although beating, bleaching, and additives are known to improve industrially produced Kraft pulp papers, properties are limited by the quality of the fibers. While the use of nanocellulose has been shown to significantly increase paper properties, the current cost associated with their production has limited their industrial relevance. Here, using a simple mild peracetic acid (PAA) delignification process on spruce, we produce hemicellulose-rich holocellulose fibers (28.8 wt %) with high intrinsic strength (1200 MPa for fibers with microfibrillar angle smaller than 10°). We show that PAA treatment causes less cellulose/hemicellulose degradation and better preserves cellulose nanostructure in comparison to conventional Kraft pulping. High-density holocellulose papers with superior mechanical properties (Young's modulus of 18 GPa and ultimate strength of 195 MPa) are manufactured using a water-based hot-pressing process, without the use of beating or additives. We propose that the preserved hemicelluloses act as "glue" in the interfiber region, improving both mechanical and optical properties of papers. Holocellulose fibers may be affordable and applicable candidates for making special paper/composites where high mechanical performance and/or optical transmittance are of interest.


Assuntos
Celulose/análogos & derivados , Papel/normas , Módulo de Elasticidade , Ácido Peracético/química , Madeira/química
16.
Bioprocess Biosyst Eng ; 41(6): 803-809, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29500661

RESUMO

Aurantiochytrium can produce significant amounts of omega-3 fatty acids, specifically docosahexaenoic acid and docosapentaenoic acid. Use of a glucose-based medium for heterotrophic growth is needed to achieve a high growth rate and production of abundant lipids. However, heat sterilization for reliable cultivation is not appropriate to heat-sensitive materials and causes a conversion of glucose via browning (Maillard) reactions. Thus, the present study investigated the use of a direct degradation of Peracetic acid (PAA) for omega-3 production by Aurantiochytrium. Polymer-based bioreactor and glucose-containing media were chemically co-sterilized by 0.04% PAA and neutralized through a reaction with ferric ion (III) in HEPES buffer. Mono-cultivation was achieved without the need for washing steps and filtration, thereby avoiding the heat-induced degradation and dehydration of glucose. Use of chemically sterilized and neutralized medium, rather than heat-sterilized medium, led to a twofold faster growth rate and greater productivity of omega-3 fatty acids.


Assuntos
Meios de Cultura/química , Ácidos Graxos Ômega-3/biossíntese , Ácido Peracético/química , Esterilização/métodos , Estramenópilas/crescimento & desenvolvimento
17.
J Prosthet Dent ; 120(1): 92-98, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29310877

RESUMO

STATEMENT OF PROBLEM: The optimal irrigating solution with antimicrobial and dentin cleansing properties for post space preparation for fiber posts is unclear. Peracetic acid is one option but is available in various chemical formulations that require evaluation. PURPOSE: The purpose of this in vitro study was to evaluate dentin surface cleanliness based on the presence of a smear layer and the number of open dentin tubules. It also investigates the chemical composition of residues after canal irrigation with a 1% peracetic acid solution (PA) at low or high concentration of hydrogen peroxide during the preparation of intracanal fiber posts. MATERIAL AND METHODS: After filling the root canals of 40 mandibular incisors, a rotary instrument was used for intracanal preparation to place fiber posts. The teeth were divided into 4 groups (n=10) according to the post space irrigation protocol as follows: CG (control): distilled water; NA (NaOCl): 2.5% sodium hypochlorite; LH: PA with low concentration of hydrogen peroxide; and HH: PA with high concentrations of hydrogen peroxide. After irrigation, the teeth were sectioned, and the intracanal dentin surface was subjected to analysis using energy dispersive spectroscopy to evaluate chemical composition and to scanning electron microscopy (×500) to evaluate the presence of the smear layer. The number of open dentin tubules was measured by scanning electron microscopy analysis (×2000) using photo-editing software. ANOVA and the Tukey test (α=.05) were used to evaluate the data, except for the presence of a smear layer, for which the Kruskal-Wallis and Dunn tests were used (α=.05). RESULTS: The highest concentrations of oxygen in the dentin residues were detected in LH and HH (P<.05); CG and NA showed similar oxygen concentrations (P>.05). NA had a higher concentration of chlorine (P<.05), whereas LH had a lower amount of smear layer and a larger number of open dentin tubules than the other groups (P<.05). These were equivalent to each other (P>.05), except for HH, which also had a larger number of open dentin tubules than CG and NA (P<.05). CONCLUSIONS: PA 1% with a low concentration of hydrogen peroxide yielded a lower amount of smear layer and a larger number of open dentin tubules in the dentin of the post space when compared with PA 1% with a high concentration of hydrogen peroxide, despite maintaining a similar oxygen concentration in these dentin residues.


Assuntos
Dentina/efeitos dos fármacos , Ácido Peracético/química , Irrigantes do Canal Radicular/química , Tratamento do Canal Radicular , Camada de Esfregaço/tratamento farmacológico , Dentina/ultraestrutura , Humanos , Peróxido de Hidrogênio/química , Técnicas In Vitro , Incisivo , Mandíbula , Microscopia Eletrônica de Varredura , Técnica para Retentor Intrarradicular , Hipoclorito de Sódio/química , Espectrometria por Raios X , Propriedades de Superfície
18.
Environ Sci Pollut Res Int ; 25(33): 32851-32859, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28210951

RESUMO

Conventional wastewater treatment is challenging in the Arctic region due to the cold climate and scattered population. Thus, no wastewater treatment plant exists in Greenland, and raw wastewater is discharged directly to nearby waterbodies without treatment. We investigated the efficiency of physicochemical wastewater treatment, in Kangerlussuaq, Greenland. Raw wastewater from Kangerlussuaq was treated by chemical coagulation and UV disinfection. By applying 7.5 mg Al/L polyaluminium chloride (PAX XL100), 73% of turbidity and 28% phosphate was removed from raw wastewater. E. coli and Enterococcus were removed by 4 and 2.5 log, respectively, when UV irradiation of 0.70 kWh/m3 was applied to coagulated wastewater. Furthermore, coagulated raw wastewater in Denmark, which has a chemical quality similar to Greenlandic wastewater, was disinfected by peracetic acid or UV irradiation. Removal of heterotrophic bacteria by applying 6 and 12 mg/L peracetic acid was 2.8 and 3.1 log, respectively. Similarly, removal of heterotrophic bacteria by applying 0.21 and 2.10 kWh/m3 for UV irradiation was 2.1 and greater than 4 log, respectively. Physicochemical treatment of raw wastewater followed by UV irradiation and/or peracetic acid disinfection showed the potential for treatment of arctic wastewater.


Assuntos
Desinfecção/métodos , Ácido Peracético/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Regiões Árticas , Bactérias/efeitos dos fármacos , Bactérias/efeitos da radiação , Dinamarca , Desinfetantes/química , Desinfetantes/farmacologia , Enterococcus/efeitos dos fármacos , Enterococcus/efeitos da radiação , Escherichia coli/efeitos dos fármacos , Escherichia coli/efeitos da radiação , Groenlândia , Processos Heterotróficos , Ácido Peracético/farmacologia , Raios Ultravioleta
19.
J Mech Behav Biomed Mater ; 77: 408-413, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29020663

RESUMO

Sterilization is the certain and absolute decontamination of microorganisms totally from all manner of alive and active species. Sterilization devices used in the sterilization processes are between laboratory and external patient application devices of biomedical device technology, and they are designed to remove equipments from germs. The application potential of hetarilazo indole based azo dyes in the biomedical sterilization are known and azo dyes come into prominence in this class because of simplicity of their synthesis and procurement of low-cost raw materials. In this work, the application potential of a novel synthesized azo dye, (E)-N-phenyl-4-(thiazole-2-yldiazenyl)aniline was investigated as an indicator in the biomedical sterilization performing the electrochemical and spectroscopic characterizations. The application of indicator was tested by ethylene oxide, hydrogen peroxide and peracetic acid sterilization techniques introducing into various sterilization rolls.


Assuntos
Compostos de Anilina/química , Compostos Azo/química , Indóis/química , Esterilização/métodos , Tiazóis/química , Colorimetria , Eletroquímica , Eletrodos , Óxido de Etileno/química , Hidrazonas/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Oxigênio/química , Ácido Peracético/química , Espectrofotometria , Espectrofotometria Ultravioleta , Propriedades de Superfície , Temperatura , Raios Ultravioleta
20.
Infect Control Hosp Epidemiol ; 38(7): 784-791, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28462746

RESUMO

OBJECTIVE Activated alkaline glutaraldehyde (GTA) remains one of the most widely used high-level disinfectants worldwide. However, several reports have highlighted the potential for nontuberculous mycobacteria to develop high-level resistance to this product. Because aldehyde resistance may lead to cross-resistance to other biocides, we investigated the susceptibility profile of GTA-resistant Mycobacterium chelonae and M. abscessus isolates to various disinfectant chemistries. METHODS High-level disinfectants commonly used in the reprocessing of endoscopes and other heat-sensitive, semicritical medical equipment, including different formulations of aldehyde-based products and oxidizing agents, were tested against 10 slow- and fast-growing, GTA-susceptible and GTA-resistant, Mycobacterium isolates in suspension tests and carrier tests at different temperatures. RESULTS While peracetic acid- and hydrogen peroxide-based disinfectants (S40, Resert XL, Reliance DG) efficiently killed all of the Mycobacterium isolates, GTA- and ortho-phthalaldehyde-based products (ie, Cidex, Aldahol, Cidex OPA) showed variable efficacy against GTA-resistant strains despite the ability of some formulations (Aldahol) to overcome the resistance of some of these isolates, especially when the temperature was increased from 20°C to 25°C. CONCLUSIONS Application permitting, oxidizing chemistries may provide a safe alternative to aldehyde-based products, particularly in GTA-resistant mycobacterial outbreaks. Infect Control Hosp Epidemiol 2017;38:784-791.


Assuntos
Aldeídos/farmacologia , Desinfetantes/farmacologia , Glutaral/farmacologia , Micobactérias não Tuberculosas/efeitos dos fármacos , Ácido Peracético/farmacologia , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana , Mycobacterium abscessus/efeitos dos fármacos , Mycobacterium chelonae/efeitos dos fármacos , Ácido Peracético/química , Temperatura
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