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Adding the adequate level of security of information systems dealing with sensitive data, privacy, or defense systems involves some form of access control. The audits performed are dealing with the determination of the allowed activities of the legal users, when attempting to access resources of the system. Usually, full access is provided after the user has been successfully authenticated through an authentication mechanism (e.g., password), while the corresponding authorization control is based on the confidentiality level of the respective resources and the authorization level assigned to each user. A very important diversification occurring in modern digital technologies is related to the identification based on blockchain technology, which is presented as a public, distributed data series, unable to modify its history and grouped in time-numbered blocks. In this work, a blockchain-based verifiable user data access control policy for secured cloud data storage is suggested for a version associated with big data in health care. It is an innovative system of applying classified access policies to secure resources in the cloud, which operates based on blockchain technology. System evaluation is carried out by studying a case in its resilience to Eclipse attack under different malicious user capabilities for routing table poisoning. [ABSTRACT FROM AUTHOR]

Streptococcus mutans (S. mutans) has been proved to be the main aetiological factor in dental caries. Curcumin, a natural product, has been shown to exhibit therapeutic antibacterial activity, suggesting that curcumin may be of clinical interest. The objective of this study is to evaluate the inhibitory effects of curcumin on metabolism and biofilm formation in S. mutans using a vitro biofilm model in an artificial oral environment. S. mutans biofilms were treated with varying concentrations of curcumin. The biofilm metabolism and biofilm biomass were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and the crystal violet assay. Confocal laser scanning microscopy was used to analyse the composition and extracellular polysaccharide content of S. mutans biofilm after curcumin treatment. The biofilm structure was evaluated using a scanning electron microscope. The gene expression of virulence-related factors was assessed by real-time PCR. The antibiofilm effect of curcumin was compared with that of chlorhexidine. The sessile minimum inhibitory concentration (SMIC50%) of curcumin against S. mutans biofilm was 500 μM. Curcumin reduced the biofilm metabolism from 5 min to 24 h. Curcumin inhibited the quantity of live bacteria and total bacteria in both the short term (5 min) and the long term. Moreover, curcumin decreased the production of extracellular polysaccharide in the short term. The expression of genes related to extracellular polysaccharide synthesis, carbohydrate metabolism, adherence, and the two-component transduction system decreased after curcumin treatment. The chlorhexidine-treated group showed similar results. We speculate that curcumin has the capacity to be developed as an alternative agent with the potential to reduce the pathogenic traits of S. mutans biofilm. [ABSTRACT FROM AUTHOR]

Background. Daodi medicinal material is widely used in Chinese herb medication. However, there is a lack of systematic methodology for identifying characteristics associated with good quality and reliable efficacy of Daodi med-material. Purpose. The purpose of this study is to provide some evidence to further substantiate the use of Daodi medicinal materials. Methods. Seven relevant databases were searched before July 2014. Two evaluators were responsible for screening and categorizing the results. The data was analyzed with Microsoft Excel 2007 and SPSS 21.0 statistical software. Results. Overall, 107 articles were systematically analyzed. Of these studies, 55.1% (59/107) focused on the methodology to assess Daodi med-material, and 38.3% (41/107) were interested in med-material ingredients, soil physical and chemical properties, and the geological background system (GBS). Only 6.5% (7/107) of studies were mainly conducted as clinical trials and animal experiments. Conclusion. Comparisons between Daodi and non-Daodi materials have been studied mainly in terms of the ingredients or composition of medical materials, soil physics and chemistry, and the GBS, and some identifying methodologies have been created to identify Daodi attributes. Until now, there is still no consensus of comparison criteria between Daodi and non-Daodi medicinal material. Only a few studies were conducted through animal experiments and clinical trials to determine Daodi superiority. [ABSTRACT FROM AUTHOR]