12 research outputs found

    Hand hygiene during the spread of COVID-19: a cross-sectional study of awareness and practices among academic institutions in Lebanon

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    IntroductionDuring the pandemic, the World Health Organization has recommended hand hygiene as one of the effective preventive measures to limit the global spread of COVID-19. However, the awareness gap of hand hygiene protocols could increase the spread of COVID-19 and consequently increase the absenteeism rate among academic institutions. This study aims to assess hand hygiene awareness and practices levels among various university communities in Lebanon.MethodsA cross-sectional study was conducted between December 2021 and June 2022 among 1,291 participants from academic settings in Lebanese universities. An online survey (score-based questionnaire) of hand hygiene was conducted to evaluate the awareness and practices among university communities (faculty, staff, and students). Mann-Whitney and Kruskal-Wallis tests were used to determine whether significant differences exist in the levels of awareness with regard to gender, age, provinces, educational level, and university status. Pearson’s chi-squared test was applied to assess differences among the sample characteristics and participants’ practice of hand hygiene.ResultsIt was found that most of the participants showed a moderate level of awareness (76.4%) with a mean score of 7.59 out of 12 (SD = 1.68). The Mann-Whitney test indicated that females recorded higher levels of awareness than males with a significant difference of 102, 104: p < 0.05. Another notable variable was the educational level of the participants with university degrees holders recording higher scores of awareness than the ones with high school degrees as per the Kruskal-Wallis test (p < 0.05). Significant differences were also shown in awareness scores among the age groups and the university status (p < 0.05). The Pearson’s chi-squared test results showed that females used alcohol-based hand rubs or soap and water more frequently than males (p < 0.05). However, males significantly preferred the frequent use of water alone compared to females (p < 0.05).ConclusionThe study findings highlighted the necessity of awareness campaigns and health educational programs addressing the technical skills of hand hygiene among both genders (especially males) of the academic communities in Lebanon

    Evaluation of public awareness and performance toward the safe use of household disinfectants-cleaners to prevent COVID-19 in the Emirate of Abu Dhabi

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    IntroductionDisinfection is one of the most effective hygienic practices that would limit the spread of the Coronavirus Disease (COVID-19) through deactivating the coronavirus on contaminated skin, supplies, and surfaces. However, the type and concentration of disinfectants should be carefully selected to avoid damaging surfaces and to limit the side effects of these chemicals on household members and users. The aim of this study is to assess the public levels of awareness and performance concerning the safe use of household cleaning products and disinfectants during the spread of COVID-19 in the Emirate of Abu Dhabi.MethodsThe cross-sectional study was conducted between October and December 2021 among 750 residents of Abu Dhabi, Al Dhafrah, and Al-Ain regions. A google survey was distributed electronically for the online recruitment of the general population. Mann-Whitney and Kruskal-Wallis tests were used to determine whether significant differences exist in the levels of awareness and performance with regard to gender, region, education level, and diagnosis with COVID-19. Spearman correlation was used to test if any correlation existed between levels of awareness and performance. Kruskal-Wallis test was also used to check if significant differences exist in the mean score of performance with respect to irritation-to-poisoning symptoms.ResultsThe study population recorded a lower mean score of awareness (5.37 out of 12) than performance (11.75 out of 16). The majority of the study population claimed a minimum of one irritation-to-poisoning symptom during the handling of household cleaners and disinfectants. Significant differences exist in the awareness and performance mean scores among various educational levels (P < 0.001). The level of awareness was statistically significant with regard to infection with SARS-CoV-2 (P < 0.05). Also, the level of performance was significantly different between males and females (P < 0.001). Kruskal-Wallis test showed that the mean score of performance is statistically significant with all the studied irritation-to poisoning symptoms (P < 0.05).ConclusionsAwareness campaigns and training programs are recommended to address the safe use of household cleaning products and disinfectants in the United Arab Emirates (UAE)

    Activité biologique et électrochimie de protéines membranes, de bactéries et de bactériophages dans un matériau sol-gel hybride

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    Accès restreint aux membres de l'Université de Lorraine jusqu'au 2015-10-01The work reported in this thesis has been developed at the interface between three disciplines, i.e., electrochemistry, material science and microbiology. The purpose of this research was first to study the activity of bacteria immobilized in silica-based films prepared by the sol-gel process on electrode surfaces. Potential applications concern biosensors, bioreactors and biofuel cells. Electrochemically assisted bacterial encapsulation has been developed, using sol electrolysis to immobilize Escherichia coli in a hybrid sol-gel layer. The combination of silica precursors, chitosan, poly(ethylene glycol) and trehalose allowed preservation of cell membrane integrity and metabolic activity. Electrochemistry was then considered as an analytical method. Shewanella putrefaciens and Pseudomonas fluorescens have been encapsulated in silica-based films and the electron transfer reactions from bacteria to different redox mediators have been monitored. Single-walled carbon nanotubes functionalized with ferrocene moieties and bovine heart cytochrome c have been considered as redox shuttles to facilitate the electron transfer in the non-conducting silica matrix, leading to the elaboration of artificial biofilms. Interestingly, these two classes of mediator, i.e. chemical and biological, led to different substrate sensitivity because of their different mechanism of interaction with the bacteria. Immobilization of membrane associated redox proteins in sol-gel films have been then considered and applied for electrocatalysis. Direct and mediated electrochemical communication has been investigated between the electrode surface and cytochrome P450 (CYP1A2) or mandelate dehydrogenase, respectively, showing the interest of sol-gel to stabilize the bioelectrocatalytic reaction. Finally, the influence of encapsulation in a hybrid sol-gel matrix on the infectivity of bacteriophage [phi]X174 has been studied and the protective effect of polyethyleneimine or glycerol was shownLe travail décrit dans cette thèse a été mené à l'interface entre trois disciplines: l'électrochimie, la science des matériaux et la microbiologie. L'objectif de cette recherche était tout d'abord d'étudier l'activité de bactéries immobilisées dans un film de silice déposé par le procédé sol-gel à la surface d'électrodes. Les applications potentielles de ce travail fondamental sont les biocapteurs, les bioréacteurs ou biopiles. L'encapsulation bactérienne assistée par électrochimie a été développée en utilisant l'électrolyse du sol de départ pour immobiliser la bactérie Escherichia Coli dans une couche mince sol-gel hybride. La combinaison de précurseurs de silice, de chitosan, de poly(ehtylène glycol) et de tréhalose permet de préserver l'intégrité membranaire et l'activité métabolique. L'électrochimie a ensuite été utilisée comme moyen analytique. Shewanella putrefaciens et Pseudomonas fluorescens ont été encapsulées dans un film à base de silice et les réactions de transfert d'électron de la bactérie à différent médiateurs rédox ont été analysées. Des nanotubes de carbone fonctionnalisés par des espèces ferrocène et la protéine rédox cytochrome c ont été utilisés pour faciliter ce transfert électronique au sein de cette matrice de silice isolante, permettant l'obtention d'un biofilm artificiel. Ces deux types de médiateurs, chimique ou biologique, ont conduit à des sensibilités différentes de la bioélectrode à l'ajout du substrat pourvoyeur d'électron en raison des mécanismes différents impliqués pour transférer ces électrons. L'immobilisation de protéines rédox membranaires a également été considérée dans ces couches minces inorganiques pour favoriser la stabilité de la réponse électrocatalytique. Les protéines considérées impliquent des mécanismes de transfert électronique différents, soit direct pour le cytochrome P450 (CYP1A2), soit médié pour la mandélate déshydrogénase. Finalement, l'influence de l'encapsulation dans une matrice sol-gel hybride sur l'infectivité du bactériophage [phi]X174 a été étudiée, montrant l'effet protecteur de la polyéthylènenimine ou du glycéro

    Biological activity and/or electrochemistry of membrane proteins, bacteria and bacteriophages in a hybrid-based sol-gel material

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    Le travail décrit dans cette thèse a été mené à l'interface entre trois disciplines: l'électrochimie, la science des matériaux et la microbiologie. L'objectif de cette recherche était tout d'abord d'étudier l'activité de bactéries immobilisées dans un film de silice déposé par le procédé sol-gel à la surface d'électrodes. Les applications potentielles de ce travail fondamental sont les biocapteurs, les bioréacteurs ou biopiles. L'encapsulation bactérienne assistée par électrochimie a été développée en utilisant l'électrolyse du sol de départ pour immobiliser la bactérie Escherichia Coli dans une couche mince sol-gel hybride. La combinaison de précurseurs de silice, de chitosan, de poly(ehtylène glycol) et de tréhalose permet de préserver l'intégrité membranaire et l'activité métabolique. L'électrochimie a ensuite été utilisée comme moyen analytique. Shewanella putrefaciens et Pseudomonas fluorescens ont été encapsulées dans un film à base de silice et les réactions de transfert d'électron de la bactérie à différent médiateurs rédox ont été analysées. Des nanotubes de carbone fonctionnalisés par des espèces ferrocène et la protéine rédox cytochrome c ont été utilisés pour faciliter ce transfert électronique au sein de cette matrice de silice isolante, permettant l'obtention d'un biofilm artificiel. Ces deux types de médiateurs, chimique ou biologique, ont conduit à des sensibilités différentes de la bioélectrode à l'ajout du substrat pourvoyeur d'électron en raison des mécanismes différents impliqués pour transférer ces électrons. L'immobilisation de protéines rédox membranaires a également été considérée dans ces couches minces inorganiques pour favoriser la stabilité de la réponse électrocatalytique. Les protéines considérées impliquent des mécanismes de transfert électronique différents, soit direct pour le cytochrome P450 (CYP1A2), soit médié pour la mandélate déshydrogénase. Finalement, l'influence de l'encapsulation dans une matrice sol-gel hybride sur l'infectivité du bactériophage [phi]X174 a été étudiée, montrant l'effet protecteur de la polyéthylènenimine ou du glycérolThe work reported in this thesis has been developed at the interface between three disciplines, i.e., electrochemistry, material science and microbiology. The purpose of this research was first to study the activity of bacteria immobilized in silica-based films prepared by the sol-gel process on electrode surfaces. Potential applications concern biosensors, bioreactors and biofuel cells. Electrochemically assisted bacterial encapsulation has been developed, using sol electrolysis to immobilize Escherichia coli in a hybrid sol-gel layer. The combination of silica precursors, chitosan, poly(ethylene glycol) and trehalose allowed preservation of cell membrane integrity and metabolic activity. Electrochemistry was then considered as an analytical method. Shewanella putrefaciens and Pseudomonas fluorescens have been encapsulated in silica-based films and the electron transfer reactions from bacteria to different redox mediators have been monitored. Single-walled carbon nanotubes functionalized with ferrocene moieties and bovine heart cytochrome c have been considered as redox shuttles to facilitate the electron transfer in the non-conducting silica matrix, leading to the elaboration of artificial biofilms. Interestingly, these two classes of mediator, i.e. chemical and biological, led to different substrate sensitivity because of their different mechanism of interaction with the bacteria. Immobilization of membrane associated redox proteins in sol-gel films have been then considered and applied for electrocatalysis. Direct and mediated electrochemical communication has been investigated between the electrode surface and cytochrome P450 (CYP1A2) or mandelate dehydrogenase, respectively, showing the interest of sol-gel to stabilize the bioelectrocatalytic reaction. Finally, the influence of encapsulation in a hybrid sol-gel matrix on the infectivity of bacteriophage [phi]X174 has been studied and the protective effect of polyethyleneimine or glycerol was show

    Biological activity and/or electrochemistry of membrane proteins, bacteria and bacteriophages in a hybrid-based sol-gel material

    No full text
    Le travail décrit dans cette thèse a été mené à l'interface entre trois disciplines: l'électrochimie, la science des matériaux et la microbiologie. L'objectif de cette recherche était tout d'abord d'étudier l'activité de bactéries immobilisées dans un film de silice déposé par le procédé sol-gel à la surface d'électrodes. Les applications potentielles de ce travail fondamental sont les biocapteurs, les bioréacteurs ou biopiles. L'encapsulation bactérienne assistée par électrochimie a été développée en utilisant l'électrolyse du sol de départ pour immobiliser la bactérie Escherichia Coli dans une couche mince sol-gel hybride. La combinaison de précurseurs de silice, de chitosan, de poly(ehtylène glycol) et de tréhalose permet de préserver l'intégrité membranaire et l'activité métabolique. L'électrochimie a ensuite été utilisée comme moyen analytique. Shewanella putrefaciens et Pseudomonas fluorescens ont été encapsulées dans un film à base de silice et les réactions de transfert d'électron de la bactérie à différent médiateurs rédox ont été analysées. Des nanotubes de carbone fonctionnalisés par des espèces ferrocène et la protéine rédox cytochrome c ont été utilisés pour faciliter ce transfert électronique au sein de cette matrice de silice isolante, permettant l'obtention d'un biofilm artificiel. Ces deux types de médiateurs, chimique ou biologique, ont conduit à des sensibilités différentes de la bioélectrode à l'ajout du substrat pourvoyeur d'électron en raison des mécanismes différents impliqués pour transférer ces électrons. L'immobilisation de protéines rédox membranaires a également été considérée dans ces couches minces inorganiques pour favoriser la stabilité de la réponse électrocatalytique. Les protéines considérées impliquent des mécanismes de transfert électronique différents, soit direct pour le cytochrome P450 (CYP1A2), soit médié pour la mandélate déshydrogénase. Finalement, l'influence de l'encapsulation dans une matrice sol-gel hybride sur l'infectivité du bactériophage [phi]X174 a été étudiée, montrant l'effet protecteur de la polyéthylènenimine ou du glycérolThe work reported in this thesis has been developed at the interface between three disciplines, i.e., electrochemistry, material science and microbiology. The purpose of this research was first to study the activity of bacteria immobilized in silica-based films prepared by the sol-gel process on electrode surfaces. Potential applications concern biosensors, bioreactors and biofuel cells. Electrochemically assisted bacterial encapsulation has been developed, using sol electrolysis to immobilize Escherichia coli in a hybrid sol-gel layer. The combination of silica precursors, chitosan, poly(ethylene glycol) and trehalose allowed preservation of cell membrane integrity and metabolic activity. Electrochemistry was then considered as an analytical method. Shewanella putrefaciens and Pseudomonas fluorescens have been encapsulated in silica-based films and the electron transfer reactions from bacteria to different redox mediators have been monitored. Single-walled carbon nanotubes functionalized with ferrocene moieties and bovine heart cytochrome c have been considered as redox shuttles to facilitate the electron transfer in the non-conducting silica matrix, leading to the elaboration of artificial biofilms. Interestingly, these two classes of mediator, i.e. chemical and biological, led to different substrate sensitivity because of their different mechanism of interaction with the bacteria. Immobilization of membrane associated redox proteins in sol-gel films have been then considered and applied for electrocatalysis. Direct and mediated electrochemical communication has been investigated between the electrode surface and cytochrome P450 (CYP1A2) or mandelate dehydrogenase, respectively, showing the interest of sol-gel to stabilize the bioelectrocatalytic reaction. Finally, the influence of encapsulation in a hybrid sol-gel matrix on the infectivity of bacteriophage [phi]X174 has been studied and the protective effect of polyethyleneimine or glycerol was shownNANCY-INPL-Bib. électronique (545479901) / SudocMETZ-SCD (574632105) / SudocSudocFranceF

    Evaluation of awareness and performance towards COVID-related disinfectant use among the university communities in Lebanon

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    Abstract Background The fast spread of COVID-19 reinforced the daily use of disinfectants around the world. However, the awareness gap of disinfectant use could lead to health risks during the prevention of the pandemic. This study aims to assess the level of awareness and performance towards COVID-related disinfectant use among various university communities (student, staff, and faculty) in Lebanon. Methods: A cross-sectional study was conducted between December 2021 and June 2022 among 925 participants (males and females aged between 18 and 64 years old) from academic settings in Lebanese universities using convenience sampling. An online validated survey (score-based questionnaire) of personal disinfectants’ utilization was conducted to evaluate the awareness and performance levels using SPSS (version 21). Mann–Whitney and Kruskal–Wallis tests were used to check significant differences in awareness and performance levels among gender, age, provinces, educational level, university status, and field of study. Friedman test was used to test for significant differences in performance level questions pre-and post-COVID-19. The Spearman correlation test was used to determine the correlation between the awareness and performance of the respondents regarding the use of disinfectants. Results: It was found that the majority of the respondents showed a weak level of awareness (70.8%) while their performance (61.9%) was moderate. Spearman’s correlation analysis concluded a weak correlation between the awareness and performance levels (p < 0.01). The Mann–Whitney test indicated that there was a significant difference (p < 0.05) in awareness and performance levels between males and females. Another notable variable was the educational level of the respondents (p < 0.05) with postgraduate degrees holders recording higher mean scores of awareness than the ones with undergraduate and high school degrees as per Kruskal–Wallis test. Significant differences were shown in awareness scores among the age groups and in performance scores among the field of study (p < 0.05). Conclusions: The study findings highlighted the necessity of awareness campaigns and training programs addressing the technical handling of disinfectants among the communities in Lebanon. Lebanese governmental authorities (Ministry of Public Health, MoPH, and Ministry of Education and Higher Education, MEHE), and the healthcare professionals and public health researchers in Lebanon may utilize this new evidence to initiate public health interventions as a part of the United Nations (UN) sustainability goal of wellbeing (Sustainable Development Goal 3, SDG 3)

    Sol–gel based ‘artificial’ biofilm from Pseudomonas fluorescens using bovine heart cytochrome c as electron mediator

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    Bovine heart cytochrome c can serve as electron mediator between Pseudomonas fluorescens bacteria immobilized in a sol–gel film and a glassy carbon electrode surface. Such system illustrates the concept of ‘artificial’ biofilm in which strategies suggested in natural biofilms to transfer electrons are mimicked. Keywords: Artificial biofilm, Cytochrome c, Pseudomonas fluorescens, Bioelectrochemical system, Sol–ge

    Electrochemically assisted bacteria encapsulation in thin hybrid sol–gel films

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    International audienceA novel method, based on the electrochemical manipulation of the sol-gel process, was developed to immobilize bacteria in thin hybrid sol-gel films. This enabled the safe immobilization of Escherichia coli on electrode surfaces. E. coli strains C600, MG1655 pUCD607 and MG1655 pZNTA-GFP were incorporated and physically encapsulated in a hybrid sol-gel matrix and the metabolic activity and membrane integrity of the bacteria were assessed as a function of the aging time in the absence of nutrients at +4 degrees C or -80 degrees C. LIVE/DEAD BacLight bacterial viability analysis detected by epifluorescence microscopy indicated the preservation of 95% of E. coli C600 membrane integrity in the sol-gel film. The presence of chitosan, trehalose and polyethylene glycol additives was shown to strongly improve the viability of E. coli cells in the electrodeposited matrix for 1 month after encapsulation. Finally, the bioluminescent activity of E. coli MG1655 pUCD607 was preserved by approximately 50% of the cells present in such composite films

    Immobilization of membrane-bounded (S)-mandelate dehydrogenase in sol-gel matrix for electroenzymatic synthesis

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    International audienceMembrane-bounded (S)-mandelate dehydrogenase has been immobilized on the surface of glassy carbon and carbon felt electrodes by encapsulation in a silica film obtained by sol-gel chemistry. Such bioelectrochemical system has been used for the first time for electroenzymatic conversion of (S)-mandelic acid to phenylglyoxylic acid. Apparent Km in this sol-gel matrix was 0.7 mM in the presence of ferrocenedimethanol, a value in the same order of magnitude as reported previously for vesicles in solution with other electron acceptors, i.e., Fe(CN)(6)(3-) or 2,6-dichloroindophenol. The bioelectrode shows very good operational stability for more than 6 days. This stability was definitively improved by comparison to a bioelectrode prepared by simple adsorption of the proteins on the electrode surface (fast activity decrease during the first 15 h of experiment). Optimal electroenzymatic reaction was achieved at pH 9 and 40 degrees C. Apparent Km of the protein activity was 3 times higher in carbon felt electrode than on glassy carbon surface, possibly because of transport limitations in the porous architecture of the carbon felt A good correlation was found between electrochemical data and chromatographic characterization of the reaction products in the bioelectrochemical reactor

    Electrochemical activity of cytochrome P450 1A2: the relevance of O2 control and the natural electron donor

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    The direct electrochemical response of membrane-bound human cytochrome P450 1A2 (CYP1A2) was studied on pyrolytic graphite electrodes, while encapsulated in a sol-gel matrix. The enzymatic reduction of O2 was evaluated in the presence and absence of its electron donor partner, cytochrome P450 oxidoreductase (CPR). When used without CPR, CYP1A2 was shown to be highly sensitive to O2 even in the presence of residual amounts. Under aerobic conditions (air-saturated solutions), the catalytic signal attributed to the reaction with O2 was lost, suggesting the enzyme was inactivated. In contrast, the CYP1A2/CPR complex retained O2 reductase activity with high O2 concentration in solution. The results demonstrated a crucial role of CPR in stabilizing the immobilized CYP1A2 enzyme and in the preservation of O2 electrocatalysis, when using this electrochemical set-up. Though the enzyme's monooxygenase activity towards caffeine was not detected, this study highlights the complexity of coupling CYP1A2 reduction currents with substrate turnover, owing to the simultaneous electrochemical measurement of the O2 reduction reaction
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