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In this work, titania nanoparticles (TiO2NPs) and silver nanoparticles (AgNPs) were combined in situ to obtain a single TiO2–Ag nanoplatform with synergistic antibacterial effects and perspectives in biological applications. To improve colloidal stability in the aqueous environment, the bifunctional (3-mercaptopropyl)-trimethoxysilane (MPTMS) and sodium 3-mercapto-1-propanesulfonate (3MPS) were used as stabilizing agents for covalent binding to TiO2NP (formation of Ti–O–Si chemical bonds) and AgNP surfaces (through the Ag–S bond), respectively. Synthesis conditions were optimized by tuning the Ag content decorating the TiO2NPs, and the colloidal stability, size, morphology, and chemical composition were studied in both solution and solid-state by UV–visible, Fourier-transform infrared, 1H NMR, X-ray photoelectron spectroscopy, field emission scanning electron microscopy-energy-dispersive X-ray spectroscopy, transmission electron microscopy, inductively coupled plasma optical emission spectrometry, dynamic light scattering, and ζ-potential. The antibacterial activities of these nanohybrids were investigated on Gram-positive and Gram-negative bacteria, and the results showed an enhanced antibacterial effect arising from the combination of TiO2NPs and AgNPs in the nanohybrid with the lower Ag content (more than 60% in the case of S. aureus exposed to TiO2–Ag), compared to the pristine TiO2NPs and control groups. Electron paramagnetic resonance with spin trapping detected the presence of hydroxyl radicals both in the nanohybrids and in the pristine TiO2NPs, supporting the hypothesis that the antibacterial effect is related to the presence of reactive oxygen species. The results of this research contribute to the synthesis of new potent antimicrobial nanohybrids for applications in more complex biological media. [ABSTRACT FROM AUTHOR]

Purpose:To identify and assess, among the participants in the RENEB (Realizing the European Network of Biodosimetry) project, the emergency preparedness, response capabilities and resources that can be deployed in the event of a radiological or nuclear accident/incident affecting a large number of individuals. These capabilities include available biodosimetry techniques, infrastructure, human resources (existing trained staff), financial and organizational resources (including the role of national contact points and their articulation with other stakeholders in emergency response) as well as robust quality control/assurance systems. Materials and methods:A survey was prepared and sent to the RENEB partners in order to acquire information about the existing, operational techniques and infrastructure in the laboratories of the different RENEB countries and to assess the capacity of response in the event of radiological or nuclear accident involving mass casualties. The survey focused on several main areas: laboratory’s general information, country and staff involved in biological and physical dosimetry; retrospective assays used, the number of assays available per laboratory and other information related to biodosimetry and emergency preparedness. Following technical intercomparisons amongst RENEB members, an update of the survey was performed one year later concerning the staff and the available assays. Conclusions:The analysis of RENEB questionnaires allowed a detailed assessment of existing capacity of the RENEB network to respond to nuclear and radiological emergencies. This highlighted the key importance of international cooperation in order to guarantee an effective and timely response in the event of radiological or nuclear accidents involving a considerable number of casualties. The deployment of the scientific and technical capabilities existing within the RENEB network members seems mandatory, to help other countries with less or no capacity for biological or physical dosimetry, or countries overwhelmed in case of a radiological or nuclear accident involving a large number of individuals. [ABSTRACT FROM PUBLISHER]

Purpose: In the EC-funded project RENEB (Realizing the European Network in Biodosimetry), physical methods applied to fortuitous dosimetric materials are used to complement biological dosimetry, to increase dose assessment capacity for large-scale radiation/nuclear accidents. This paper describes the work performed to implement Optically Stimulated Luminescence (OSL) and Electron Paramagnetic Resonance (EPR) dosimetry techniques. Materials and methods: OSL is applied to electronic components and EPR to touch-screen glass from mobile phones. To implement these new approaches, several blind tests and inter-laboratory comparisons (ILC) were organized for each assay. Results: OSL systems have shown good performances. EPR systems also show good performance in controlled conditions, but ILC have also demonstrated that post-irradiation exposure to sunlight increases the complexity of the EPR signal analysis. Conclusions: Physically-based dosimetry techniques present high capacity, new possibilities for accident dosimetry, especially in the case of large-scale events. Some of the techniques applied can be considered as operational (e.g. OSL on Surface Mounting Devices [SMD]) and provide a large increase of measurement capacity for existing networks. Other techniques and devices currently undergoing validation or development in Europe could lead to considerable increases in the capacity of the RENEB accident dosimetry network. [ABSTRACT FROM AUTHOR]

Lithium-oxygen aprotic batteries (aLOBs) are highly promising next-generation secondary batteries due to their high theoretical energy density. However, the practical implementation of these batteries is hindered by parasitic reactions that negatively impact their reversibility and cycle life. One of the challenges lies in the oxidation of Li 2 O 2 , which requires large overpotentials if not catalyzed. To address this issue, redox mediators (RMs) have been proposed to reduce the oxygen evolution reaction (OER) overpotentials. In this study, we focus on a lithium iodide RM and investigate its role on the degradation chemistry and the release of singlet oxygen in aLOBs, in different solvent environments. Specifically, we compare the impact of a polar solvent, dimethyl sulfoxide (DMSO), and a low polarity solvent, tetraglyme (G4). We demonstrate a strong interplay between solvation, degradation, and redox mediation in OER by LiI in aLOBs. The results show that LiI in DMSO-based electrolytes leads to extensive degradation and to 1 O 2 release, affecting the cell performance, while in G4-based electrolytes, the release of 1 O 2 appears to be suppressed, resulting in better cyclability.

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event., Materials and Methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners., Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes)., Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested.

Purpose: In the frame of the QA program of RENEB, an inter-laboratory comparison (ILC) of calibration sources used in biological dosimetry was achieved to investigate the influence of calibration practices and protocols on the results of the dose estimation performance as a first step to harmonization and standardization of dosimetry and irradiation practices in the European biological dosimetry network., Materials and Methods: Delivered doses by irradiation facilities used by RENEB partners were determined with EPR/alanine dosimetry system. Dosimeters were irradiated in the same conditions as blood samples. A short survey was also performed to collect the information needed for the data analysis and evaluate the diversity of practices., Results: For most of partners the deviation of delivered dose from the targeted dose remains below 10%. Deviations larger than 10% were observed for five facilities out of 21. Origins of the largest discrepancies were identified. Correction actions were evaluated as satisfactory. The re-evaluation of some ILC results for the fluorescence in situ hybridization (FISH) and premature chromosome condensation (PCC) assays has been performed leading to an improvement of the overall performances., Conclusions: This work has shown the importance of dosimetry in radiobiology studies and the needs of harmonization, standardization in irradiation and dosimetry practices and educational training for biologists using ionizing radiation.

Dosimetry based on the detection by electron paramagnetic resonance (EPR) spectroscopy of ionizing radiation-induced radicals is an established method for the retrospective dosimetry of past exposures and the dosimetry of potentially exposed persons in radiological emergencies. The dose is estimated by measuring the physical damage induced in materials contained in objects placed on or next to the potentially exposed person. The aim of this paper is to survey the current literature about methodologies and materials that have been proposed for EPR dosimetry, in order to identify those that could be suitable for population triage according to criteria such as ubiquity, non invasiveness and easy sample collection, presence of a post-irradiation EPR signal, negligible background signal, linearity of dose-response relationship, minimum detection limit and post-irradiation signal stability. The paper will survey the features of sugar, plastics, glass, clothing tissues, and solid biological tissues (nails, hair and calcified tissues).