Cytotoxicity of seven recent dentine bonding agents on mouse 3T3 fibroblast cells

Today it is generally accepted that most bonding agents are cytotoxic. In this study the relative cyto-toxicity of seven recent dentine bonding agents on mouse 3T3 fibroblast cells were investigated. Materials and Methods. Near-confluent mouse 3T3 fibro- blast cells were exposed to Dulbecco Modified Eagle’s Medium containing extractions from the seven different bonding agents. The cell survival rate was then determined using the standard MTT assay. Results. The cell survival rate ranking is: iBond (94%) < Gbond (78%) < Xeno V (71%) < Adper Easy Bond (63%) < Xeno V+ (61%) < Adper Scotchbond SE (33%) < XP Bond (32%). Part A of Adper Scotchbond SE had a survival rate of 35% and part B 38%. These two parts did not differ significantly. Adper Scotchbond SE and XP Bond do not differ significantly. While Xeno V+, Xeno V and Adper Easy Bond do not differ. (p < 5%; Tukey-Kramer Multiple-Comparison Test). Conclusion. All of the tested adhesive bonding agents were cytotoxic with survival rate of 3T3 cells between 94% to 31%. Of the 7 bonding agents tested iBond was found to be only slightly toxic and by far the least toxic. The two bonding agents (XP Bond and Adper Scotchbond SE) containing UDMA plus TEGDMA plus HEMA plus camphorquinone were found to be the most toxic

Insights into chitosan hydrogels on dentine bond strength and cytotoxicity

Contemporary dental adhesives show favorable im- mediate results in terms of bonding effectiveness. However, the durability of resin-dentin bonds is their major problem. Materials and Methods: Preparation of 3 chitosan-antioxidant hydrogels was achieved us- ing modified hydrogel preparation method. Their effect on the bond strength to dentine both short term (after 24 hours) and long term (after 6 months) were evaluated using shear bond strength measurements using Instron Universal Testing Mascine). The SEM was used to study the surface of the hydrogels. The cell survival rate (cytotoxicity) of the antioxidants re- sveratrol, β-carotene and propolis towards Balb/c 3T3 mouse fibroblast cells was also assessed using the standard MTT assay. Results: It was found that chi- tosan-H treated dentine gives significantly (p propolis (68%) > resveratrol (33%). Conclusion: the antioxidant-chitosan hydro- gels significantly improved bonding to dentine with or without phosphoric acid treatment. The pH of the growth medium had a high influence on the cell survival rate of Balb/c mouse 3T3 fibroblast cells. The release of the antioxidant β-carotene would not have an influence on the pulp cells. These materials might address the current perspectives for improving bond durability.DDF fund of the South African Dental Association; School of Dentistry and Oral Health, Griffith UniversityWeb of Scienc

Smartphone data evaluation model : identifying authentic smartphone data

Ever improving smartphone technology, along with the widespread use of the devices to accomplish daily tasks, leads to the collection of rich sources of smartphone data. Smartphone data are, however, susceptible to change and can be altered intentionally or accidentally by end-users or installed applications. It becomes, therefore, important to establish the authenticity of smartphone data, confirming the data refer to actual events, before submitting the data as potential evidence. This paper focuses on data created by smartphone applications and the techniques that can be used to establish the authenticity of the data. To identify authentic smartphone data, a better understanding of the smartphone, related smartphone applications and the environment in which the smartphone operates are required. From the gathered knowledge and insight, requirements are identified that authentic smartphone data must adhere to. These requirements are captured in a new model to assist digital forensic professionals with the evaluation of smartphone data. Experiments, involving different smartphones, are conducted to determine the practicality of the new evaluation model with the identification of authentic smartphone data. The presented results provide preliminary evidence that the suggested model offers the necessary guidance to identify authentic smartphone data.http://www.elsevier.com/locate/diinhj2019Computer Scienc

Synthesis and In Vitro (Anticancer) Evaluation of eta(6)-Arene Ruthenium Complexes Bearing Stannyl Ligands

Treatment of the known half-sandwich complexes of the type [(eta(6)-C6H6)RuCl2(P(OR)(3))] (R = Me or Ph) with SnCl2 yielded three new half-sandwich ruthenium complexes (C1-C3): [(eta(6)-C6H6)RuCl(SnCl3)(P(OMe)(3))] (C1), [(eta(6)-C6H6)RuCl(SnCl3)(P(OPh)(3))] (C2) and the bis-stannyl complex [(eta(6)-C6H6)Ru(SnCl3)(2)(P(OMe)(3))] (C3) by facile insertion of SnCl2 into the Ru-Cl bonds. Treatment of the known complexes [(eta(6)-C6H6)RuCl(SnCl3)(PPh3)] and [(eta(6)-C6H6)RuCl2(PPh3)] with 4-dimethylaminopyridine (DAMP) and ammonium tetrafluoroborate afforded the complex salts: [(eta(6)-C6H6)Ru(SnCl3)(PPh3)(DAMP)]+BF4- (C4) and [(eta(6)-C6H6)RuCl(PPh3)(DAMP)]+BF4- (C5) respectively. Complexes C1-C5 have been fully characterized by spectroscopic means (IR, UV-vis, multinuclear NMR, ESI-MS) and their thermal behaviour elucidated by thermal gravimetric analysis (TGA). Structural characterization by single crystal X-ray crystallography of the novel complex C2 and [(eta(6)-C6H6)RuCl2(P(OPh)(3))], the latter having escaped elucidation by this method, is also reported. Finally, the cytotoxicity of the complexes was determined on the A2780 (human ovarian cancer), A2780cisR (human ovarian cis-platin-resistant cancer), and the HEK293 (human embryonic kidney) cell lines and discussed, and an attempt is made to elucidate the effect of the stannyl ligand on cytotoxicity

Cell cycle checkpoint status in human malignant mesothelioma cell lines: response to gamma radiation

Knowledge of the function of the cell cycle checkpoints in tumour cells may be important to develop treatment strategies for human cancers. The protein p53 is an important factor that regulates cell cycle progression and apoptosis in response to drugs. In human malignant mesothelioma, p53 is generally not mutated, but may be inactivated by SV40 early region T antigen (SV40 Tag). However, the function of p53 has not been investigated in mesothelioma cells. Here, we investigated the function of the cell cycle checkpoints in six human mesothelioma cell lines (HMCLs) by studying the cell distribution in the different phases of the cell cycle by flow cytometry, and expression of cell cycle proteins, p53, p21WAF1/CIP1 and p27KIP1. In addition, we studied p53 gene mutations and expression of SV40 Tag. After exposure to γ-radiation, HMCLs were arrested either in one or both phases of the cell cycle, demonstrating a heterogeneity in cell cycle control. G1 arrest was p21WAF1/CIP1- and p53-dependent. Lack of arrest in G1 was not related to p53 mutation or binding to SV40 Tag, except in one HMCL presenting a missense mutation at codon 248. These results may help us to understand mesothelioma and develop new treatments

Exploring The Versatility Of Ionic Liquids : From fundamental understanding to materials inspired from ionic liquids

Ionic liquids (ILs) have gained popularity as “green” and safe replacements for conventional organic solvents. They are defined as ionic salts displaying a melting point below 100 °C. Some of their unique characteristics also include negligible vapour pressure, good electrical conductivity as well as good thermal and chemical stability. While their “green” nature has since been disputed, they can be used and applied in many additional fields, such as solar energy production, new lighting technology and much more.  In this thesis, the aim is to gain fundamental knowledge on ILs, specifically their structures and behaviour, in order to design materials tailored for specific applications. We also aim to use ILs to access otherwise difficult to synthesize materials and study their properties and applications. The thermal properties of ILs are one of their most important characteristics. However, it is still poorly understood how the structural aspects of ILs influence their particular thermal behaviour. By studying different systems, we derived relationships between the structure and the thermal behaviour of ILs. Hydrogen bonding and other supramolecular interactions play a major role in controlling both the melting temperature and the IL's ability to support a liquid crystalline mesophase. This control was shown both in a series of ILs based on 1-alkyl-3-dodecylimidazolium bromide and in a series of ILs based on azobenzene-imidazolium compounds. The stability issues associated with the electrolytes used in dye-sensitized solar cells (DSSCs) present a major disadvantage. We tested using ILs as electrolytes to avoid this problem. In our study, we used 1,3-dialkyltriazolium ILs as electrolytes in combination with the iodide redox couple, and not only was the stability of the DSSC improved but also the performance of IL-based DSSCs. Efficient luminescent materials are always sought after. Using ILs in combination with lanthanides, we achieved highly luminescent compounds as well as some magnetic ones. ILs can also be used to access anhydrous forms of otherwise hydrophilic species, such as ions of the lanthanides. We have used acetate ILs to attain water free complexes of the ions from the whole lanthanide series, starting from the hydrated species. This simple process could be applied to more species of hydrophilic metals that are otherwise known to form hydrates. Finally, the ligand obtained through ILs, 1,3-diethylimidazole-2-thione was used to aid in the studying of phase transitions when combined with zinc chloride (ZnCl2). It helped to reveal a yet unseen amorphous step in the solid-solid phase transition from a single crystal into another one, where morphology of the particle was preserved. I forsee that more fundamental structural studies can be conducted by forcing the coordination of the soft-donor nitrogen onto lanthanides by using dicyanamide ILs in the future

Development of efficient perovskite solar cells using a low-temperature liquid process

Perovskites-photovoltaic cells are a type of photovoltaic cells which include a chemical compound having perovskite structure, most often a hybrid organic-inorganic lead or a tin halide, in its light-converting active layer. The efficiency of photovoltaic cells used in these materials is increasing constantly since the beginning of the new millennium. It went from 3.8% in 2009 [6] to 22.1% [7] in early 2016 [8].Up until today, this is the fastest development in the history of the photovoltaic history. To this day, some stability problems unfortunately still remain unsolved. However, this technology still exhibits a significant margin to improve performance and low production costs. This means that perovskite cells have become commercially attractive, and start-up companies already announce modules on the market by 2019. This study concluded that the addition of halogenated bidentate additives such as 1,8 Diiodooctane (DIO) not only influenced the performances of perovskite solar cells but also their stability over time. By fine elemental analysis, it was concluded that the addition of chlorine in the solution did not imply the substitution of iodide by chlorine in the structure. Chlorine is therefore believed to play a role in getting rid of the excess of methylamine, thus helping stabilizing the cell and enhancing its performance. As requested by the industry, this work demonstrated the feasibility of replacing the electron transport layer (ETL) of TiO2 by a materials obtained by liquid low-temperature process (&lt;150°C)

Exploring The Versatility Of Ionic Liquids : From fundamental understanding to materials inspired from ionic liquids

Ionic liquids (ILs) have gained popularity as “green” and safe replacements for conventional organic solvents. They are defined as ionic salts displaying a melting point below 100 °C. Some of their unique characteristics also include negligible vapour pressure, good electrical conductivity as well as good thermal and chemical stability. While their “green” nature has since been disputed, they can be used and applied in many additional fields, such as solar energy production, new lighting technology and much more.  In this thesis, the aim is to gain fundamental knowledge on ILs, specifically their structures and behaviour, in order to design materials tailored for specific applications. We also aim to use ILs to access otherwise difficult to synthesize materials and study their properties and applications. The thermal properties of ILs are one of their most important characteristics. However, it is still poorly understood how the structural aspects of ILs influence their particular thermal behaviour. By studying different systems, we derived relationships between the structure and the thermal behaviour of ILs. Hydrogen bonding and other supramolecular interactions play a major role in controlling both the melting temperature and the IL's ability to support a liquid crystalline mesophase. This control was shown both in a series of ILs based on 1-alkyl-3-dodecylimidazolium bromide and in a series of ILs based on azobenzene-imidazolium compounds. The stability issues associated with the electrolytes used in dye-sensitized solar cells (DSSCs) present a major disadvantage. We tested using ILs as electrolytes to avoid this problem. In our study, we used 1,3-dialkyltriazolium ILs as electrolytes in combination with the iodide redox couple, and not only was the stability of the DSSC improved but also the performance of IL-based DSSCs. Efficient luminescent materials are always sought after. Using ILs in combination with lanthanides, we achieved highly luminescent compounds as well as some magnetic ones. ILs can also be used to access anhydrous forms of otherwise hydrophilic species, such as ions of the lanthanides. We have used acetate ILs to attain water free complexes of the ions from the whole lanthanide series, starting from the hydrated species. This simple process could be applied to more species of hydrophilic metals that are otherwise known to form hydrates. Finally, the ligand obtained through ILs, 1,3-diethylimidazole-2-thione was used to aid in the studying of phase transitions when combined with zinc chloride (ZnCl2). It helped to reveal a yet unseen amorphous step in the solid-solid phase transition from a single crystal into another one, where morphology of the particle was preserved. I forsee that more fundamental structural studies can be conducted by forcing the coordination of the soft-donor nitrogen onto lanthanides by using dicyanamide ILs in the future

Do you see me the way I see myself? Narcissists are less prone to illusion of transparency than other people

People tend to believe that their internal states are transparent to others (e.g. illusion of transparency), and even more when they are self-centred. Would it be the case for narcissistic individuals who are highly self-centred? Three studies investigated whether narcissists feel more transparent because they are egocentric, or whether they feel less transparent because they are socially skilled. Using a vignette method, Study 1 showed that the more participants were narcissists, the less they felt transparent with regard to their emotions, values and behaviour. Study 2 further showed that this association was stronger when narcissistic characteristics were valorised. In addition, the negative link between narcissism and felt transparency was mediated by self-monitoring. Using a face-to-face interaction, Study 3 provided evidence that participants high on narcissism were less prone to illusion of transparency. Overall our studies suggest that narcissists’ meta-perception is more accurate, less egocentric because they are socially skilled.info:eu-repo/semantics/publishe