Data Privacy Protection Based on Micro Aggregation with Dynamic Sensitive Attribute Updating.

With the rapid development of information technology, large-scale personal data, including those collected by sensors or IoT devices, is stored in the cloud or data centers. In some cases, the owners of the cloud or data centers need to publish the data. Therefore, how to make the best use of the data in the risk of personal information leakage has become a popular research topic. The most common method of data privacy protection is the data anonymization, which has two main problems: (1) The availability of information after clustering will be reduced, and it cannot be flexibly adjusted. (2) Most methods are static. When the data is released multiple times, it will cause personal privacy leakage. To solve the problems, this article has two contributions. The first one is to propose a new method based on micro-aggregation to complete the process of clustering. In this way, the data availability and the privacy protection can be adjusted flexibly by considering the concepts of distance and information entropy. The second contribution of this article is to propose a dynamic update mechanism that guarantees that the individual privacy is not compromised after the data has been subjected to multiple releases, and minimizes the loss of information. At the end of the article, the algorithm is simulated with real data sets. The availability and advantages of the method are demonstrated by calculating the time, the average information loss and the number of forged data.

[Protective effect and mechanism of total lignans from Tibetan medicinal Herpetospermum seeds on carbon tetrachloride-induced liver fibrosis in rats].

This experiment was aimed to discuss the protective effect and mechanism of total lignans from Tibetan medicinal Herpetospermum seeds on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Forty-eight male Sprague-Dawley rats were randomly divided into the blank control group (G1), model group (G2), total lignans high, middle and low dose groups (400,200, and 100 mg•kg⁻¹â€¢d⁻¹)(G3/4/5) and the glycyrrhizin positive control group (25 mg•kg⁻¹â€¢d⁻¹)(G6), n=8 in each group. The rats in blank group received normal feeding; the rats in model group, total lignans low, middle and high dose groups and glycyrrhizic group were subcutaneously in jected with 3 mL•kg⁻¹ olive oilsolution containing 40%CCl4 every two or three days for Eight weeks. During the course, the rats inblank group and model group were orally administered with 2 mL normal saline, and the rats in total lignans groups and the glycyrrhizin positive control group received corresponding doses of drugs by intragastric administration. Eight weeks later, after the the last time modeling, the rats were sacrificed. Then the biochemical analysis was used to determine alanine aminotransferase(ALT), aspartate aminotransferase(AST), and alkaline phosphatase (ALP) levels in serum while enzyme-linked immuno sorbent assay(ELISA) was applied for detecting transforming growth factor ß1(TGF-ß1), hyaluronic acid(HA), hydroxy-proline(HYP) and superoxide dismutase(SOD) levels in serum. HE and Masson's trichrome stainings were conducted in liver tissues to observe the pathological variations and grades of hepatic fibrosis. The results showed that as compared with the model group, the levels of ALT, AST, ALP, TGF-ß1, HA, HYP and SOD in serum of total lignans groups were significantly decreased (P<0.05, P<0.01); levels of SOD in the liver tissue homogenate were increased(P<0.05, P<0.01); the pathological damage of the liver tissues were relieved (P<0.05, P<0.01), and liver fibrosis scores were decreased(P<0.05, P<0.01). The above experimentsindicated that total lignans from Tibetan medicinal Herpetospermum seeds can effectively reduce carbon tetrachloride-induced hepatic injury of rat liver fibrosis, reduce the degree of liver fibrosis, and its mechanism maybe associated with down-regulating TGF-ß1 expression.