A Review on the Security of the Ethereum-Based DeFi Ecosystem

Decentralized finance(DeFi)is a general term for a series of financial products and services.It is based on blockchain technology and has attracted people’s attention because of its open,transparent,and intermediary free.Among them,the DeFi ecosystem based on Ethereum-based blockchains attracts the most attention.However,the current decentralized financial system built on the Ethereum architecture has been exposed to many smart contract vulnerabilities during the last few years.Herein,we believe it is time to improve the understanding of the prevailing Ethereum-based DeFi ecosystem security issues.To that end,we investigate the Ethereum-based DeFi security issues:1)inherited from the real-world financial system,which can be solved by macro-control;2)induced by the problems of blockchain architecture,which require a better blockchain platform;3)caused by DeFi invented applications,which should be focused on during the project development.Based on that,we further discuss the current solutions and potential directions ofDeFi security.According to our research,we could provide a comprehensive vision to the research community for the improvement of Ethereum-basedDeFi ecosystem security.

Study on Mott-Insulator-Superfluid Phase Transition in Symmetric and Unsymmetric Double-Chain Bose-Hubbard Model

The symmetric and the asymmetric double-chain Bose-Hubbard Models( BHMs) are studied by the mean-field theory. By using Landau's quantum phase transition theory,phase diagrams for systems with different hopping energies and repulsive interactions are obtained. Thereby,Mott-insulator-superfluid( MISF)phase transition boundaries are determined. Our results show that tunneling effects between two chains provide additional channels for particles hopping between corresponding optical lattice sites of different chains,which makes easier for systems to transit from MI to SF phase. The two-site parity function is also utilized to investigate the properties of the system near the quantum phase transit point.We found that the increase of inter-chain hopping will reinforce the tunneling effects between two chains,and reduce the intrachain tunneling effects within the same chain.

Textbook outcome in gallbladder carcinoma after curative-intent resection:a 10-year retrospective single-center study

Background:Textbook outcome(TO)can guide decision-making among patients and clinicians during preoperative patient selection and postoperative quality improvement.We explored the factors associated with achieving a TO for gallbladder carcinoma(GBC)after curative-intent resection and analyzed the effect of adjuvant chemotherapy(ACT)on TO and non-TO patients.Methods:A total of 540 patients who underwent curative-intent resection for GBC at the Department of Hepatobiliary Surgery of the First Affiliated Hospital of Xi’an Jiaotong University from January 2011 to December 2020 were retrospectively analyzed.Multivariable logistic regression was used to investigate the factors associated with TO.Results:Among 540 patients with GBC who underwent curative-intent resection,223 patients(41.3%)achieved a TO.The incidence of TO ranged from 19.0%to 51.0%across the study period,with a slightly increasing trend over the study period.The multivariate analysis showed that non-TO was an independent risk factor for prognosis among GBC patients after resection(P=0.003).Age≤60 years(P=0.016),total bilirubin(TBIL)level≤34.1 mmol/L(P<0.001),well-differentiated tumor(P=0.008),no liver involvement(P<0.001),and T1-2 stage disease(P=0.006)were independently associated with achieving a TO for GBC after resection.Before and after propensity score matching(PSM),the overall survival outcomes of non-TO GBC patients who received ACT and those who did not were statistically significant;ACT improved the prognosis of patients in the non-TO group(P<0.05).Conclusion:Achieving a TO is associated with a better long-term prognosis among GBC patients after curative-intent resection,and ACT can improve the prognosis of those with non-TO.