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Airdrop is a crucial concept in tokenomics. Startups of decentralized applications (DApps) reward early supporters by airdropping newly issued tokens up to a certain amount as a free giveaway. This naturally induces greedy hackers, called Sybils, to create multiple accounts for more shares. Most airdrops have prerequisites for qualification, in which utilizing these DApps is unsurprisingly the principal. One particular characteristic of DApps is to implement users' interactions with them in the form of token transfer transactions or smart contract calling transactions on public blockchains. We argue that these individual transactions could reveal underlying signatures of their sending accounts. Specifically, accounts controlled by the same Sybil may exhibit some common behaviors. A careful analysis of Sybil's behaviors shows that accounts controlled by the same Sybil may produce similar DApp activities and regular token transfer patterns. We model the transactions as graphs by representing accounts as vertices and transactions as edges. When multiple accounts receive tokens from the same Sybil to conduct interactions with DApps, we inspect the graphs for these activities and patterns to detect suspicious accounts. We demonstrate the effectiveness of the proposed method in a recent airdrop by presenting the suspicious accounts controlled by Sybils. All the detected accounts exhibit similar interaction activities and regular transfer patterns.

We have reported the high-pressure behavior of energetic material trimethylsilane azide ((CH3)3SiN3, TMSiN3) by in situ Raman scattering and synchrotron angle-dispersive X-ray diffraction (ADXRD) measurements in diamond anvil cells with a pressure up to ∼40 GPa at ambient temperature. The analyses of Raman spectra showed two liquid-liquid phase transitions at 0.13 and 7.9 GPa. The XRD results verified that TMSiN3 remained in a liquid state throughout the phase transitions. In the pressure range of 0.13-2.6 GPa, the distortion of the Si-C3 bond and the shortening of the bond between azide group and silicon atom lead to the first phase transition. The second transition is ascribed to the rotation of methyl group at 7.9 GPa. With further compression, the azide groups become increasingly asymmetric, and completely amorphous at 33.8 GPa. This paper is useful to understand the behavior of azide group and the molecular structural evolution of organic azide under high pressure. The unique high-pressure behavior of the azide group in TMSiN3 may be useful for improving in the formation of the polynitrogen compound with azides.

Objective The aim of the study is to summarize the effect of intensive-dose continuous renal replacement therapy (CRRT) on the mortality and other clinical outcomes. Methods A systematic search for randomized, controlled trials (RCTs) was performed. We estimated pooled relative ratios and 95% confidence intervals using fixed effects model or random effects model as appropriate. Results We analyzed data extracted from 6 RCTs comparing the effects of intensive and less intensive dose of RRT on clinical outcomes. A total of 3490 patients were included, including 1803 patients received intensive CRRT doses and 1687 received less-intensive doses. Overall, 44.5% (802/1803) patients died in the intensive dose group compared with 45.4% (766/1687) in the dose group, with the risk ratio of 0.91 (95% confidence interval: 0.77-1.08). The heterogeneity was remarkable (I2 = 75%), and the subgroup analysis limited to patients with sepsis failed to find a reason for the heterogeneity. The intensive dose showed no beneficial effects on other clinical outcomes, and the complications associated with RRT were higher in the intensive dose group. Conclusion This meta-analysis provides additional evidence that the higher dose of CRRT is not sufficient in reducing the mortality in critically ill patients with acute renal failure.

Strain ZF-7 was isolated from defective fruits in this study, and its product was determined as bacterial cellulose in view of the results of cellulose special reaction, FTIR spectroscopy analysis, and cellulose hydrolysis experiments. Based on morphological, physiological, and biochemical characteristics, ZF-7 was identified by 16S rDNA sequences and systematic analysis. The results indicated that 16S rDNA sequence of ZF-7 had 99.5 % similarity to the partial sequence of Bacillus amyloliquefaciens, suggesting that ZF-7 was categorized as a species of B. amyloliquefaciens, and denominated as B. amyloliquefaciens ZF-7. The fermentation performance of ZF-7 under shaking and static flasks was inspected preliminary, and the BC production was 6.6 and 6.2 g/L, respectively.