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1.
Chem Eng J ; 454: 140188, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36373160

RESUMO

Ozone - a powerful antimicrobial agent, has been extensively applied for decontamination purposes in several industries (including food, water treatment, pharmaceuticals, textiles, healthcare, and the medical sectors). The advent of the COVID-19 pandemic has led to recent developments in the deployment of different ozone-based technologies for the decontamination of surfaces, materials and indoor environments. The pandemic has also highlighted the therapeutic potential of ozone for the treatment of COVID-19 patients, with astonishing results observed. The key objective of this review is to summarize recent advances in the utilisation of ozone for decontamination applications in the above-listed industries while emphasising the impact of key parameters affecting microbial reduction efficiency and ozone stability for prolonged action. We realise that aqueous ozonation has received higher research attention, compared to the gaseous application of ozone. This can be attributed to the fact that water treatment represents one of its earliest applications. Furthermore, the application of gaseous ozone for personal protective equipment (PPE) and medical device disinfection has not received a significant number of contributions compared to other applications. This presents a challenge for which the correct application of ozonation can mitigate. In this review, a critical discussion of these challenges is presented, as well as key knowledge gaps and open research problems/opportunities.

3.
Environ Sci Technol ; 51(11): 5907-5912, 2017 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-28447452

RESUMO

To the best of our knowledge, this study represents the first observation of multiday persistence of an indoor aerosol transformation linked to a kitchen degreaser containing monoethanol amine (MEA). MEA remaining on the cleaned surfaces and on a wiping paper towel in a trash can was able to transform ammonium sulfate and ammonium nitrate into (MEA)2SO4 and (MEA)NO3. This influence persisted for at least 60 h despite a high average ventilation rate. The influence was observed using both offline (filters, impactors, and ion chromatography analysis) and online (compact time-of-flight aerosol mass spectrometer) techniques. Substitution of ammonia in ammonium salts was observed not only in aerosol but also in particles deposited on a filter before the release of MEA. The similar influence of other amines is expected based on literature data. This influence represents a new pathway for MEA exposure of people in an indoor environment. The stabilizing effect on indoor nitrate also causes higher indoor exposure to fine nitrates.


Assuntos
Aerossóis , Aminas , Sulfato de Amônio , Poluentes Atmosféricos , Amônia , Monitoramento Ambiental , Nitratos , Tamanho da Partícula
4.
Mol Cell Proteomics ; 14(9): 2357-74, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25693799

RESUMO

There is an increasing need in biology and clinical medicine to robustly and reliably measure tens to hundreds of peptides and proteins in clinical and biological samples with high sensitivity, specificity, reproducibility, and repeatability. Previously, we demonstrated that LC-MRM-MS with isotope dilution has suitable performance for quantitative measurements of small numbers of relatively abundant proteins in human plasma and that the resulting assays can be transferred across laboratories while maintaining high reproducibility and quantitative precision. Here, we significantly extend that earlier work, demonstrating that 11 laboratories using 14 LC-MS systems can develop, determine analytical figures of merit, and apply highly multiplexed MRM-MS assays targeting 125 peptides derived from 27 cancer-relevant proteins and seven control proteins to precisely and reproducibly measure the analytes in human plasma. To ensure consistent generation of high quality data, we incorporated a system suitability protocol (SSP) into our experimental design. The SSP enabled real-time monitoring of LC-MRM-MS performance during assay development and implementation, facilitating early detection and correction of chromatographic and instrumental problems. Low to subnanogram/ml sensitivity for proteins in plasma was achieved by one-step immunoaffinity depletion of 14 abundant plasma proteins prior to analysis. Median intra- and interlaboratory reproducibility was <20%, sufficient for most biological studies and candidate protein biomarker verification. Digestion recovery of peptides was assessed and quantitative accuracy improved using heavy-isotope-labeled versions of the proteins as internal standards. Using the highly multiplexed assay, participating laboratories were able to precisely and reproducibly determine the levels of a series of analytes in blinded samples used to simulate an interlaboratory clinical study of patient samples. Our study further establishes that LC-MRM-MS using stable isotope dilution, with appropriate attention to analytical validation and appropriate quality control measures, enables sensitive, specific, reproducible, and quantitative measurements of proteins and peptides in complex biological matrices such as plasma.


Assuntos
Proteínas de Neoplasias/sangue , Neoplasias/metabolismo , Peptídeos/análise , Proteômica/métodos , Cromatografia Líquida/métodos , Humanos , Marcação por Isótopo , Espectrometria de Massas/métodos , Proteínas de Neoplasias/química , Proteínas de Neoplasias/isolamento & purificação , Neoplasias/sangue , Peptídeos/química , Reprodutibilidade dos Testes
6.
Mol Cell Proteomics ; 13(4): 1034-49, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24505115

RESUMO

Breast cancer is a heterogeneous disease whose molecular diversity is not well reflected in clinical and pathological markers used for prognosis and treatment selection. As tumor cells secrete proteins into the extracellular environment, some of these proteins reach circulation and could become suitable biomarkers for improving diagnosis or monitoring response to treatment. As many signaling pathways and interaction networks are altered in cancerous tissues by protein phosphorylation, changes in the secretory phosphoproteome of cancer tissues could reflect both disease progression and subtype. To test this hypothesis, we compared the phosphopeptide-enriched fractions obtained from proteins secreted into conditioned media (CM) derived from five luminal and five basal type breast cancer cell lines using label-free quantitative mass spectrometry. Altogether over 5000 phosphosites derived from 1756 phosphoproteins were identified, several of which have the potential to qualify as phosphopeptide plasma biomarker candidates for the more aggressive basal and also the luminal-type breast cancers. The analysis of phosphopeptides from breast cancer patient plasma and controls allowed us to construct a discovery list of phosphosites under rigorous collection conditions, and second to qualify discovery candidates generated from the CM studies. Indeed, a set of basal-specific phosphorylation CM site candidates derived from IBP3, CD44, OPN, FSTL3, LAMB1, and STC2, and luminal-specific candidates derived from CYTC and IBP5 were selected and, based on their presence in plasma, quantified across all cell line CM samples using Skyline MS1 intensity data. Together, this approach allowed us to assemble a set of novel cancer subtype specific phosphopeptide candidates for subsequent biomarker verification and clinical validation.


Assuntos
Adenocarcinoma/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Fosfoproteínas/metabolismo , Proteômica/métodos , Neoplasias da Mama/sangue , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Fosforilação , Células Tumorais Cultivadas
7.
Proc Natl Acad Sci U S A ; 110(16): 6601-6, 2013 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-23576753

RESUMO

Large-scale proteomic approaches have identified numerous mitochondrial acetylated proteins; however in most cases, their regulation by acetyltransferases and deacetylases remains unclear. Sirtuin 3 (SIRT3) is an NAD(+)-dependent mitochondrial protein deacetylase that has been shown to regulate a limited number of enzymes in key metabolic pathways. Here, we use a rigorous label-free quantitative MS approach (called MS1 Filtering) to analyze changes in lysine acetylation from mouse liver mitochondria in the absence of SIRT3. Among 483 proteins, a total of 2,187 unique sites of lysine acetylation were identified after affinity enrichment. MS1 Filtering revealed that lysine acetylation of 283 sites in 136 proteins was significantly increased in the absence of SIRT3 (at least twofold). A subset of these sites was independently validated using selected reaction monitoring MS. These data show that SIRT3 regulates acetylation on multiple proteins, often at multiple sites, across several metabolic pathways including fatty acid oxidation, ketogenesis, amino acid catabolism, and the urea and tricarboxylic acid cycles, as well as mitochondrial regulatory proteins. The widespread modification of key metabolic pathways greatly expands the number of known substrates and sites that are targeted by SIRT3 and establishes SIRT3 as a global regulator of mitochondrial protein acetylation with the capability of coordinating cellular responses to nutrient status and energy homeostasis.


Assuntos
Lisina/metabolismo , Redes e Vias Metabólicas/fisiologia , Mitocôndrias Hepáticas/metabolismo , Proteínas Mitocondriais/metabolismo , Proteômica/métodos , Sirtuína 3/metabolismo , Acetilação , Animais , Biologia Computacional , Espectrometria de Massas , Redes e Vias Metabólicas/genética , Camundongos , Modelos Biológicos , Sirtuína 3/deficiência
8.
Mol Cell Proteomics ; 12(9): 2623-39, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23689285

RESUMO

Multiple reaction monitoring (MRM) mass spectrometry coupled with stable isotope dilution (SID) and liquid chromatography (LC) is increasingly used in biological and clinical studies for precise and reproducible quantification of peptides and proteins in complex sample matrices. Robust LC-SID-MRM-MS-based assays that can be replicated across laboratories and ultimately in clinical laboratory settings require standardized protocols to demonstrate that the analysis platforms are performing adequately. We developed a system suitability protocol (SSP), which employs a predigested mixture of six proteins, to facilitate performance evaluation of LC-SID-MRM-MS instrument platforms, configured with nanoflow-LC systems interfaced to triple quadrupole mass spectrometers. The SSP was designed for use with low multiplex analyses as well as high multiplex approaches when software-driven scheduling of data acquisition is required. Performance was assessed by monitoring of a range of chromatographic and mass spectrometric metrics including peak width, chromatographic resolution, peak capacity, and the variability in peak area and analyte retention time (RT) stability. The SSP, which was evaluated in 11 laboratories on a total of 15 different instruments, enabled early diagnoses of LC and MS anomalies that indicated suboptimal LC-MRM-MS performance. The observed range in variation of each of the metrics scrutinized serves to define the criteria for optimized LC-SID-MRM-MS platforms for routine use, with pass/fail criteria for system suitability performance measures defined as peak area coefficient of variation <0.15, peak width coefficient of variation <0.15, standard deviation of RT <0.15 min (9 s), and the RT drift <0.5min (30 s). The deleterious effect of a marginally performing LC-SID-MRM-MS system on the limit of quantification (LOQ) in targeted quantitative assays illustrates the use and need for a SSP to establish robust and reliable system performance. Use of a SSP helps to ensure that analyte quantification measurements can be replicated with good precision within and across multiple laboratories and should facilitate more widespread use of MRM-MS technology by the basic biomedical and clinical laboratory research communities.


Assuntos
Cromatografia Líquida/instrumentação , Cromatografia Líquida/métodos , Espectrometria de Massas/instrumentação , Espectrometria de Massas/métodos , Sequência de Aminoácidos , Animais , Bovinos , Limite de Detecção , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/metabolismo , Padrões de Referência , Software , Fatores de Tempo
9.
Electrophoresis ; 35(24): 3487-97, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24853916

RESUMO

Human plasma contains proteins that reflect overall health and represents a rich source of proteins for identifying and understanding disease pathophysiology. However, few studies have investigated changes in plasma phosphoproteins. In addition, little is known about the normal variations in these phosphoproteins, especially with respect to specific sites of modification. To address these questions, we evaluated variability in plasma protein phosphorylation in healthy individuals using multiple reaction monitoring (MRM) and SWATH-MS2 data-independent acquisition. First, we developed a discovery workflow for phosphopeptide enrichment from plasma and identified targets for MRM assays. Next, we analyzed plasma from healthy donors using an analytical workflow consisting of MRM and SWATH-MS2 that targeted phosphopeptides from 58 and 68 phosphoproteins, respectively. These two methods produced similar results showing low variability in 13 phosphosites from 10 phosphoproteins (CVinter < 30%) and high interpersonal variation of 16 phosphosites from 14 phosphoproteins (CVinter > 30%). Moreover, these phosphopeptides originate from phosphoproteins involved in cellular processes governing homeostasis, immune response, cell-extracellular matrix interactions, lipid and sugar metabolism, and cell signaling. This limited assessment of technical and biological variability in phosphopeptides generated from plasma phosphoproteins among healthy volunteers constitutes a reference for future studies that target protein phosphorylation as biomarkers.


Assuntos
Cromatografia Líquida/métodos , Fosfopeptídeos/sangue , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Adolescente , Adulto , Sequência de Aminoácidos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fosforilação , Fluxo de Trabalho , Adulto Jovem
10.
Mol Cell Proteomics ; 11(5): 202-14, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22454539

RESUMO

Despite advances in metabolic and postmetabolic labeling methods for quantitative proteomics, there remains a need for improved label-free approaches. This need is particularly pressing for workflows that incorporate affinity enrichment at the peptide level, where isobaric chemical labels such as isobaric tags for relative and absolute quantitation and tandem mass tags may prove problematic or where stable isotope labeling with amino acids in cell culture labeling cannot be readily applied. Skyline is a freely available, open source software tool for quantitative data processing and proteomic analysis. We expanded the capabilities of Skyline to process ion intensity chromatograms of peptide analytes from full scan mass spectral data (MS1) acquired during HPLC MS/MS proteomic experiments. Moreover, unlike existing programs, Skyline MS1 filtering can be used with mass spectrometers from four major vendors, which allows results to be compared directly across laboratories. The new quantitative and graphical tools now available in Skyline specifically support interrogation of multiple acquisitions for MS1 filtering, including visual inspection of peak picking and both automated and manual integration, key features often lacking in existing software. In addition, Skyline MS1 filtering displays retention time indicators from underlying MS/MS data contained within the spectral library to ensure proper peak selection. The modular structure of Skyline also provides well defined, customizable data reports and thus allows users to directly connect to existing statistical programs for post hoc data analysis. To demonstrate the utility of the MS1 filtering approach, we have carried out experiments on several MS platforms and have specifically examined the performance of this method to quantify two important post-translational modifications: acetylation and phosphorylation, in peptide-centric affinity workflows of increasing complexity using mouse and human models.


Assuntos
Mapeamento de Peptídeos/métodos , Processamento de Proteína Pós-Traducional , Proteoma/metabolismo , Software , Acetilação , Sequência de Aminoácidos , Animais , Neoplasias da Mama , Calibragem/normas , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Meios de Cultivo Condicionados/química , Feminino , Análise de Fourier , Humanos , Camundongos , Camundongos Knockout , Mitocôndrias Hepáticas/enzimologia , Mitocôndrias Musculares/metabolismo , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fosforilação , Proteoma/química , Proteoma/isolamento & purificação , Proteômica , Complexo Piruvato Desidrogenase/química , Complexo Piruvato Desidrogenase/isolamento & purificação , Complexo Piruvato Desidrogenase/metabolismo , Padrões de Referência , Espectrometria de Massas em Tandem/normas
11.
BMJ Open ; 14(2): e076194, 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38367966

RESUMO

INTRODUCTION: Children with chronic medical diseases are at an unacceptable risk of hospitalisation and death from influenza and SARS-CoV-2 infections. Over the past two decades, behavioural scientists have learnt how to design non-coercive 'nudge' interventions to encourage positive health behaviours. Our study aims to evaluate the impact of multicomponent nudge interventions on the uptake of COVID-19 and influenza vaccines in medically at-risk children. METHODS AND ANALYSES: Two separate randomised controlled trials (RCTs), each with 1038 children, will enrol a total of approximately 2076 children with chronic medical conditions who are attending tertiary hospitals in South Australia, Western Australia and Victoria. Participants will be randomly assigned (1:1) to the standard care or intervention group. The nudge intervention in each RCT will consist of three text message reminders with four behavioural nudges including (1) social norm messages, (2) different messengers through links to short educational videos from a paediatrician, medically at-risk child and parent and nurse, (3) a pledge to have their child or themselves vaccinated and (4) information salience through links to the current guidelines and vaccine safety information. The primary outcome is the proportion of medically at-risk children who receive at least one dose of vaccine within 3 months of randomisation. Logistic regression analysis will be performed to determine the effect of the intervention on the probability of vaccination uptake. ETHICS AND DISSEMINATION: The protocol and study documents have been reviewed and approved by the Women's and Children's Health Network Human Research Ethics Committee (HREC/22/WCHN/2022/00082). The results will be published via peer-reviewed journals and presented at scientific meetings and public forums. TRIAL REGISTRATION NUMBER: NCT05613751.


Assuntos
COVID-19 , Vacinas contra Influenza , Influenza Humana , Criança , Feminino , Humanos , COVID-19/prevenção & controle , SARS-CoV-2 , Influenza Humana/prevenção & controle , Vacinação , Vitória , Ensaios Clínicos Controlados Aleatórios como Assunto
12.
RSC Adv ; 13(32): 22593-22605, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37501772

RESUMO

The microbiological safety of medical equipment and general surfaces is paramount to both the well-being of patients and the public. The application of ozone (a potent oxidant) has been recognised and implemented for this purpose, globally. However, it has primarily been utilised in the gaseous and aqueous forms. In this study, we investigate the potency of fine ozone mists and evaluate the synergistic effect when combined with cationic, anionic and non-ionic surfactants (dodecyl trimethyl ammonium bromide - DTAB, sodium dodecyl sulfate - SDS, alkyl polyglycoside - APG) as well as polyethylene glycol (PEG). Ozone mist is generated via a nebuliser (equipped with a compressed gas stream) and the piezoelectric method; whereas fabric substrates contaminated with Escherichia coli and Staphylococcus aureus are utilised in this study. Contamination levels on the fabric swatches are evaluated using agar dipslides. Compared to gaseous ozonation and aqueous ozonation (via nanobubble generation), the produced ozone mists showed significantly inferior antimicrobial properties for the tested conditions (6 ppm, 5-15 min). However, the hybrid mist-based application of 'ozone + surfactants' and 'ozone + PEG' showed considerable improvements compared to their independent applications (ozone mist only and surfactant mist only). The 'ozone + DTAB' mist had the highest activity, with better results observed with the micron-mist nebuliser than the piezoelectric transducer. We propose a likely mechanism for this synergistic performance (micellar encapsulation) and demonstrate the necessity for continued developments of novel decontamination technologies.

13.
Ind Eng Chem Res ; 62(10): 4191-4209, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36943762

RESUMO

The control of infectious diseases can be improved via carefully designed decontamination equipment and systems. Research interest in ozone (a powerful antimicrobial agent) has significantly increased over the past decade. The COVID-19 pandemic has also instigated the development of new ozone-based technologies for the decontamination of personal protective equipment, surfaces, materials, and indoor environments. As this interest continues to grow, it is necessary to consider key factors affecting the applicability of lab-based findings to large-scale systems utilizing ozone. In this review, we present recent developments on the critical factors affecting the successful deployments of industrial ozone technologies. Some of these include the medium of application (air or water), material compatibility, efficient circulation and extraction, measurement and control, automation, scalability, and process economics. We also provide a comparative assessment of ozone relative to other decontamination methods/sterilization technologies and further substantiate the necessity for increased developments in gaseous and aqueous ozonation. Modeling methodologies, which can be applied for the design and implementation of ozone contacting systems, are also presented in this review. Key knowledge gaps and open research problems/opportunities are extensively covered including our recommendations for the development of novel solutions with industrial importance.

14.
Trials ; 24(1): 454, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37438776

RESUMO

BACKGROUND: Influenza and COVID-19 infections during pregnancy may have serious adverse consequences for women as well as their infants. However, uptake of influenza and COVID-19 vaccines during pregnancy remains suboptimal. This study aims to assess the effectiveness of a multi-component nudge intervention to improve influenza and COVID-19 vaccine uptake among pregnant women. METHODS: Pregnant women who receive antenatal care at five tertiary hospitals in South Australia, Western Australia and Victoria will be recruited to two separate randomised controlled trials (RCTs). Women will be eligible for the COVID-19 RCT is they have received two or less doses of a COVID-19 vaccine. Women will be eligible for the influenza RCT if they have not received the 2023 seasonal influenza vaccine. Vaccination status at all stages of the trial will be confirmed by the Australian Immunisation Register (AIR). Participants will be randomised (1:1) to standard care or intervention group (n = 1038 for each RCT). The nudge intervention in each RCT will comprise three SMS text message reminders with links to short educational videos from obstetricians, pregnant women and midwives and vaccine safety information. The primary outcome is at least one dose of a COVID-19 or influenza vaccine during pregnancy, as applicable. Logistic regression will compare the proportion vaccinated between groups. The effect of treatment will be described using odds ratio with a 95% CI. DISCUSSION: Behavioural nudges that facilitate individual choices within a complex context have been successfully used in other disciplines to stir preferred behaviour towards better health choices. If our text-based nudges prove to be successful in improving influenza and COVID-19 vaccine uptake among pregnant women, they can easily be implemented at a national level. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT05613751. Registered on November 14, 2022.


Assuntos
COVID-19 , Vacinas contra Influenza , Influenza Humana , Envio de Mensagens de Texto , Lactente , Feminino , Gravidez , Humanos , Vacinas contra Influenza/efeitos adversos , Influenza Humana/prevenção & controle , Vacinas contra COVID-19 , Gestantes , COVID-19/prevenção & controle , Vitória , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
J Proteome Res ; 11(4): 2508-20, 2012 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-22309216

RESUMO

We used a lectin chromatography/MS-based approach to screen conditioned medium from a panel of luminal (less aggressive) and triple negative (more aggressive) breast cancer cell lines (n=5/subtype). The samples were fractionated using the lectins Aleuria aurantia (AAL) and Sambucus nigra agglutinin (SNA), which recognize fucose and sialic acid, respectively. The bound fractions were enzymatically N-deglycosylated and analyzed by LC-MS/MS. In total, we identified 533 glycoproteins, ∼90% of which were components of the cell surface or extracellular matrix. We observed 1011 glycosites, 100 of which were solely detected in ≥3 triple negative lines. Statistical analyses suggested that a number of these glycosites were triple negative-specific and thus potential biomarkers for this tumor subtype. An analysis of RNaseq data revealed that approximately half of the mRNAs encoding the protein scaffolds that carried potential biomarker glycosites were up-regulated in triple negative vs luminal cell lines, and that a number of genes encoding fucosyl- or sialyltransferases were differentially expressed between the two subtypes, suggesting that alterations in glycosylation may also drive candidate identification. Notably, the glycoproteins from which these putative biomarker candidates were derived are involved in cancer-related processes. Thus, they may represent novel therapeutic targets for this aggressive tumor subtype.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Cromatografia de Afinidade/métodos , Glicoproteínas/análise , Lectinas/química , Biomarcadores Tumorais/química , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Feminino , Glicoproteínas/química , Glicoproteínas/classificação , Glicoproteínas/metabolismo , Humanos , Lectinas/metabolismo , Espectrometria de Massas/métodos , Proteínas de Membrana/análise , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Proteoma/análise , Proteoma/química
16.
Ind Eng Chem Res ; 61(27): 9600-9610, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35855724

RESUMO

For decades, ozone has been known to have antimicrobial properties when dissolved or generated in water and when utilized in its gaseous form on different substrates. This property (the ability to be used in air and water) makes it versatile and applicable to different industries. Although the medium of ozonation depends on the specific process requirements, some industries have the inherent flexibility of medium selection. Thus, it is important to evaluate the antimicrobial efficacy in both media at similar concentrations, an endeavor hardly reported in the literature. This study provides insights into ozone's efficacy in air and water using two Gram-negative bacteria (Escherichia coli NTCC1290 and Pseudomonas aeruginosa NCTC10332), two Gram-positive bacteria (Staphylococcus aureus ATCC25923 and Streptococcus mutans), and two fungi (Candida albicans and Aspergillus fumigatus). For gaseous ozonation, we utilized a custom-made ozone chamber (equipped with ultraviolet lamps), whereas an electrolysis oxygen radical generator was applied for ozone generation in water. During gaseous ozonation, the contaminated substrates (fabric swatches inoculated with bacterial and fungal suspensions) were suspended in the chamber, whereas the swatches were immersed in ozonated water for aqueous ozone treatment. The stability of ozone nanobubbles and their resulting impact on the aqueous disinfection efficiency were studied via dynamic light scattering measurements. It was observed that ozone is more effective in air than in water on all tested organisms except Staphylococcus aureus. The presented findings allow for the adjustment of the treatment conditions (exposure time and concentration) for optimal decontamination, particularly when a certain medium is preferred for ozonation.

17.
J Microbiol Methods ; 194: 106431, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35131364

RESUMO

Ozone treatment is an eco-friendly and cost-effective approach to achieve material disinfection, and this disinfection method is of utmost importance in the present global pandemic. The efficacy of ozone's oxidative potential on common microorganisms has been extensively studied, particularly in the food and water treatment industries. However, little is still understood regarding its antimicrobial capabilities for the treatment of textile substrates in air. In this study, fabric swatches inoculated with bacterial and fungal suspensions are exposed to ozone for different durations and at different ozone concentrations. Pathogenic bacteria (Escherichia coli, Staphylococcus aureus), and fungi (Aspergillus fumigatus, and Candida albicans), are the microbes utilised in this study. The efficacy of ozone is demonstrated by the complete removal of microbiota on the tested swatches when a concentration and exposure duration of 20 ppm and 4 mins are respectively maintained in a test ozone chamber. We expect the insights from this work to guide the development of new ozonation techniques capable of rapid sterilisation in industrial & public settings.


Assuntos
Ozônio , Purificação da Água , Bactérias , Desinfecção/métodos , Escherichia coli , Ozônio/farmacologia
18.
ACS Omega ; 7(47): 43006-43021, 2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36467929

RESUMO

With the advent of the COVID-19 pandemic, there has been a global incentive for applying environmentally sustainable and rapid sterilization methods, such as ultraviolet-C radiation (UVC) and ozonation. Material sterilization is a requirement for a variety of industries, including food, water treatment, clothing, healthcare, medical equipment, and pharmaceuticals. It becomes inevitable when devices and items like protective equipment are to be reused on/by different persons. This study presents novel findings on the performance of these sterilization methods using four microorganisms (Escherichia coli , Staphylococcus aureus , Candida albicans , and Aspergillus fumigatus) and six material substrates (stainless steel, polymethyl methacrylate, copper, surgical facemask, denim, and a cotton-polyester fabric). The combination of both ozone and UVC generally yields improved performance compared to their respective applications for the range of materials and microorganisms considered. Furthermore, the effectiveness of both UVC and ozone was higher when the fungi utilized were smeared onto the nonabsorbent materials than when 10 µL droplets were placed on the material surfaces. This dependence on the contaminating liquid surface area was not exhibited by the bacteria. This study highlights the necessity of adequate UVC and ozone dosage control as well as their synergistic and multifunctional attributes when sterilizing different materials contaminated with a wide range of microorganisms.

19.
Front Microbiol ; 11: 538476, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33262740

RESUMO

Aeolian prokaryotic communities (APC) are important components of bioaerosols that are transported freely or attached to dust particles suspended in the atmosphere. Terrestrial and marine ecosystems are known to release and receive significant prokaryote loads into and from the surrounded atmospheric air. However, compared to terrestrial systems, there is a lack of microbial characterization of atmospheric dust over marine systems, such as the Red Sea, which receives significant terrestrial dust loads and is centrally located within the Global Dust Belt. Prokaryotic communities are likely to be particularly important in the Global Dust Belt, the area between the west coast of North Africa and Central Asia that supports the highest dust fluxes on the planet. Here we characterize the diversity and richness of the APC over the Red Sea ecosystem, the only sea fully contained within the Global Dust Belt. MiSeq sequencing was used to target 16S ribosomal DNA of two hundred and forty aeolian dust samples. These samples were collected at ∼7.5 m high above the sea level at coastal and offshore sampling sites over a 2-year period (2015-2017). The sequencing outcomes revealed that the APC in the atmospheric dust is dominated by Proteobacteria (42.69%), Firmicutes (41.11%), Actinobacteria, (7.69%), and Bacteroidetes (3.49%). The dust-associated prokaryotes were transported from different geographical sources and found to be more diverse than prokaryotic communities of the Red Sea surface water. Marine and soil originated prokaryotes were detected in APC. Hence, depending on the season, these groups may have traveled from other distant sources during storm events in the Red Sea region, where the APC structure is influenced by the origin and the concentration of aeolian dust particles. Accordingly, further studies of the impact of atmospheric organic aerosols on the recipient environments are required.

20.
Sci Total Environ ; 719: 135177, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31864782

RESUMO

Along the past century, the Arabian Gulf has experienced a continuous and fast coastal development leading to increase the human pressures on the marine environment. The present study attempts to describe the historical changes of trace elements in the sediments of vegetated coastal habitats in the western Arabian Gulf. 210Pb-dated sediment cores collected from seagrass, mangrove and saltmarsh habitats were analyzed to evaluate historical variations in concentrations and burial rates of 20 trace elements (Al, As, Ba, Ca, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, S, Sr, V and Zn). The highest correlations (Spearman correlation coefficients ≥0.51) were found between crustal elements (Al, Fe, Co, Cr, K, Na, Mg, Mn, Ni, V, and P), suggesting a common crustal source in the Gulf. The increased concentrations of these crustal elements in modern marine sediments of the Arabian Gulf seem to be linked to increased mineral dust deposition in the area. Over the last century, both elemental concentrations and burial rates increased by factors of 1-9 and 1-15, respectively, with a remarkably fast increase occurring in the past six decades (~1960 - early 2000). This is most likely due to an increase in anthropogenic pressures along the Gulf coast. Our study demonstrates that sediments in vegetated coastal habitats provide long-term archives of trace elements concentrations and burial rates reflecting human activities in the Arabian Gulf.

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