Antimicrobial activity, toxicity and accumulated hard-tissue debris (AHTD) removal efficacy of several chelating agents

Aim: To evaluate the antimicrobial, toxicity and cleaning effectiveness of ethylenediaminetetraacetic acid (EDTA) and maleic acid (MA) alone and combined with cetrimide (CTR). Methodology: Cytotoxic and genotoxic effects were assessed on Chinese hamster cells V79 using the MTT, clonogenic and micronucleus assays, respectively. The bacterial inhibitory and bactericidal concentrations (MIC and MBC, respectively) were determined on a strain of Enterococcus faecalis. Antimicrobial tests were performed on a biofilm model after treatment with the chelating agents by using a biofilm eradication concentration (MBEC) and confocal laser scanning microscope (CLSM) assays. Quantification of cell biomass and percentage of live and dead cells in the biomass were assessed for each group. The percentage reduction of accumulated hard-tissue debris (AHTD) after root canal preparation and final irrigation protocols was evaluated by micro-CT. Statistical tests of one-way analysis of variance (anova), Bonferroni test, Kruskal\u2013Wallis test, Dunn\u2019s multiple comparison test and Wilcoxon matched-pairs signed-rank tests were used. Results: Cetrimide alone as well as in combination with EDTA and MA at dilutions of 1/10 and 1/100 was significantly more toxic as compared to untreated controls (P < 0.001). All tested mixtures were nontoxic at a dilution of 1/1000. EDTA retained a weak inhibitory and bactericidal effect against planktonic cells, whilst MA inhibited cells growth and killed 99.9% of the cells when diluted. CTR revealed the most prominent effect, being inhibitory and bactericidal, also when diluted. Cetrimide alone or combined with EDTA was able to remove, respectively, 40% (P < 0.01) and 60% (P < 0.001) of the entire biomass after 1 min. Conversely, MA alone and in combination with CTR did not have a significant effect on biomass reduction. After final irrigation, the AHTD volume was significantly decreased in all groups (P < 0.05). EDTA + CTR and MA + CTR were associated with a significant reduction in the percentage of AHTD on the entire root canal compared to the same solutions without surfactant. Conclusions: 7% MA was less cytotoxic in comparison with 17% EDTA. The addition of cetrimide to EDTA and MA removed accumulated hard-tissue debris effectively from the canal walls and increased their antimicrobial activity when compared to the same solutions without detergents

Can the concentration of citric acid affects its cytotoxicity and antimicrobial activity?

Background: There has been no unanimity concerning the ideal concentration of citric acid for safe use in clinical practice. This study evaluated the cytotoxicity and the antibacterial activity in infected dentinal tubules of 10% and 1% citric acid (CA) solutions. Methods: The cytotoxicity of CA solutions in DMEM (diluted 1/10, 1/100) was assessed in L-929 fibroblasts. A broth macrodilution method (MIC and MBC) was used to assess CA antibacterial concentration. The antimicrobial activity of CA solutions was also evaluated after their final rinse inside root canals in previously Enterococcus faecalis-contaminated dentinal tubules. Ten infected dentine samples were rinsed for 5 min with 5% NaOCl and subsequently with 1% citric acid for 3 min. Another 10 were rinsed with 5% NaOCl and 10% citric acid for 3 min; the remaining four specimens were utilized as positive controls. Two uncontaminated specimens were used as negative controls. After LIVE/DEAD BacLight staining, the samples were assessed using CLSM to analyze the percentage of residual live and dead cells. Results: Both undiluted and diluted CA solutions showed severe toxicity; no changes from normal morphology were displayed when diluted 1/100. The MIC and MBC of CA were 6.25 mg/mL and 12.50 mg/mL, respectively. CA solutions demonstrated significantly low levels of bacterial counts than the positive control group, reporting a value of 9.3% for the 10% solution versus the 1% solution (35.2%). Conclusions: Despite its valuable antimicrobial properties, the cytotoxic effects of citric acid should be considered during endodontic treatment

COVID-19 information disorder:six types of harmful information during the pandemic in Europe

{Sten Hansson and Kati Orru and Sten Torpan and Asta Bäck and Austeja Kazemekaityte and Sunniva Frislid Meyer and Johanna Ludvigsen and Lucia Savadori and Alessandro Galvagni and Ala Pigrée}, {COVID-19 information disorder: six types of harmful information during the pandemic in Europe}, {Journal of Risk Research}, {24}, {3-4}, {380-393}, {2021}, {Routledge}, {10.1080/13669877.2020.1871058}, { https://doi.org/10.1080/13669877.2020.1871058}The outbreak of a novel coronavirus disease COVID-19 propelled the creation, transmission, and consumption of false information – unverified claims, misleading statements, false rumours, conspiracy theories, and so on – all around the world. When various official or unofficial sources issue erroneous, misleading or contradicting information during a crisis, people who are exposed to this may behave in ways that cause harm to the health and well-being of themselves or others, e.g., by not taking appropriate risk reducing measures or blaming or harassing vulnerable groups. To work towards a typology of informational content that may increase people’s vulnerability in the context of the coronavirus pandemic, we explored 98 instances of potentially harmful information that spread in six European countries – France, Italy, Norway, Finland, Lithuania, and Estonia – between March and May 2020. We suggest that during the pandemic, exposure to harmful information may have made people more vulnerable in six ways: (1) by discouraging appropriate protective actions against catching/spreading the virus, (2) by promoting the use of false (or harmful) remedies against the virus, (3) by misrepresenting the transmission mechanisms of the virus, (4) by downplaying the risks related to the pandemic, (5) by tricking people into buying fake protection against the virus or into revealing their confidential information, and (6) by victimising the alleged spreaders of the virus by harassment/hate speech. The proposed typology can be used to guide the development of risk communication plans to address each of these information-related vulnerabilities.publishedVersio

Life satisfaction during temporary housing after an earthquake: Comparing three cases in Italy

A disaster has a considerable impact on people who have lost their homes. We analyzed the life satisfaction of displaced people accommodated in temporary housing after three strong earthquakes that occurred in Italy in 2009 (Abruzzo), 2012 (Emilia), and 2016–17 (Central Italy). Information was obtained through an anonymous survey on a large number of variables related to socio-demographic features, temporary housing type and quality, social support and protection network, personal psychological resources and preparedness, and psychophysical health. Responses were collected through face-to-face and telephone interviews, stand-alone paper-and-pencil questionnaires, or online (N = 261). In the whole-sample analysis, the significant predictors of life satisfaction were earthquake preparedness, which earthquake out of three was experienced, protection network, accommodation type and quality, and general health status, thus highlighting the complex and multi-faceted nature of the underpinnings of life satisfaction in people displaced after an earthquake. However, different predictors explained life satisfaction in the analysis of each earthquake, pointing to the need to consider their specificity and the local context. Nevertheless, the perceived quality of the accommodation was a significant predictor both in the whole-sample analysis and in the analysis of two earthquakes (2009 Abruzzo and 2012 Emilia), highlighting the importance of providing temporary houses with appropriate properties (privacy, space, thermal and acoustic insulation, light, quality of materials, surroundings) and placed in locations that allow the resumption of life activities (e.g., education, work, socialization, health and public facilities and services)

Hypoxia and risk preferences: Mild hypoxia impacts choices for low-probability high-payoff bets

Mild degrees of hypoxia are known to exert a detrimental effect on cognitive functions. In a lab study, we assessed the effect of mild hypoxia on risk-taking behavior. Participants (N = 25) were presented with pairs of bets of equal expected monetary value, one having a higher probability of winning/losing a lower payoff (safer bet) and one having a lower probability of winning/losing a higher payoff (riskier bet). We systematically varied the ratio of the probabilities (and corresponding payoffs) of the two bets and examined how this affected participants’ choice between them. Following a familiarization session, participants performed the task twice: once in a normoxic environment (20.9% oxygen concentration) and once in a mildly hypoxic environment (14.1% oxygen concentration). Participants were not told and could not guess which environment they were in. We found a higher preference for the riskier bet in the mild hypoxic than normoxic environment but only in the loss domain. Furthermore, as the probability ratio increased, mild hypoxia increased the preference for the riskier bet in the domain of losses but decreased it for gains. The present findings support that mild hypoxia promotes riskier choices in the loss domain and provide new insights into the impact of mild hypoxia in moderating the effect of probability ratio on risky choices

Food Risk/Benefit Communication: A Systematic Review

A systematic review relevant to the following research questions was conducted (1) the extent to which different theoretical frameworks have been applied to food risk/benefit communication and (2) the impact such food risk/benefit communication interventions have had on related risk/benefit attitudes and behaviors. Fifty four papers were identified. The analysis revealed that (primarily European or US) research interest has been relatively recent. Certain food issues were of greater interest to researchers than others, perhaps reflecting the occurrence of a crisis, or policy concern. Three broad themes relevant to the development of best practice in risk (benefit) communication were identified: the characteristics of the target population; the contents of the information; and the characteristics of the information sources. Within these themes, independent and dependent variables differed considerably. Overall, acute risk (benefit) communication will require advances in communication process whereas chronic communication needs to identify audience requirements. Both citizen's risk/benefit perceptions and (if relevant) related behaviors need to be taken into account, and recommendations for behavioral change need to be concrete and actionable. The application of theoretical frameworks to the study of risk (benefit) communication was infrequent, and developing predictive models of effective risk (benefit) communication may be contingent on improved theoretical perspectives

Temporal distance reduces the attractiveness of p-bets compared to $- bets

Although people normally prefer a more certain option over a riskier option of equal expected value, sometimes they are tempted to choose the riskier, but more rewarding one. Such temptation is even stronger when people decide for the distant future as compared with the near future. In Experiments 1 and 2 we showed that increasing temporal distance makes people more likely to choose a high risk $-bet (€400, 0.02;0) over a low risk p-bet (€14, 0.60;0). Furthermore, the risk aversion shift increased proportionally to the time delay and persisted even for long delays (6 months). In Experiment 3, we showed that this temporal effect is associated with a decrease in positive feelings towards the p-bet, and with a decrease in the positive evaluation of the high-probability (60%) of the p-bet, but not with an increase of the positive evaluation of the high-payoff (400 euro) of the p-bet. In Experiment 4, we showed that increasing the salience of the probability feature tended to decrease the temporal effect, while increasing the salience of the prize did not vary the strength of the effect. Results are in line with an affect-based explanation of the temporal effect

Percezione e paura dei rischi tecnologici

Il sistema esperienziale basato sulla componente emotiva \ue8 determinante nella percezione del rischio nucleare. Tale sistema, che ha garantito la sopravvivenza dell\u2019uomo, talvolta induce in errore e non riesce a rendere conto della diversit\ue0 dei giudizi sul nucleare. Questo risultato non pu\uf2 che essere imputato all\u2019apprendimento, e in particolare al diverso tipo di apprendimento cui gli individui sono esposti