IvyCross: A Privacy-Preserving and Concurrency Control Framework for Blockchain Interoperability

Interoperability is a fundamental challenge for long-envisioned blockchain applications. A mainstream approach is to use Trusted Execution Environment (TEEs) to support interoperable off-chain execution. However, this incurs multiple TEEs configured with non-trivial storage capabilities running on fragile concurrent processing environments, rendering current strategies based on TEEs far from practical. The purpose of this paper is to fill this gap and design a practical interoperability mechanism with simplified TEEs as the underlying architecture. Specifically, we present IvyCross, a TEE-based framework that achieves low-cost, privacy-preserving, and race-free blockchain interoperability. Specifically, IvyCross allows running arbitrary smart contracts across heterogenous blockchains atop only two distributed TEE-powered hosts. We design an incentive scheme based on smart contracts to stimulate the honest behavior of two hosts, bypassing the requirement of the number of TEEs and large memory storage. We examine the conditions to guarantee the uniqueness of the Nash Equilibrium via Sequential Game Theory. Furthermore, a novel extended optimistic concurrency control protocol is designed to guarantee the correctness of concurrent execution of off-chain contracts. We formally prove the security of IvyCross in the Universal Composability framework and implement a proof-of-concept prototype atop Bitcoin, Ethereum, and FISCO BOCS. The experiments indicate that (i) IvyCross is able to support privacy-preserving and multiple-round smart contracts for cross-chain communication; (ii) IvyCross successfully decreases the off-chain costs on storage and communication of a TEE without using complex cryptographic primitives; and (iii) the total on-chain transaction fees in cross-chain communication are relatively low, within ranges of 0.2 USD ~ 1 USD

Active learning for software engineering

© 2019 Copyright held by the owner/author(s). Publication rights licensed to ACM. Software applications have grown increasingly complex to deliver the features desired by users. Software modularity has been used as a way to mitigate the costs of developing such complex software. Active learning-based program inference provides an elegant framework that exploits this modularity to tackle development correctness, performance and cost in large applications. Inferred programs can be used for many purposes, including generation of secure code, code re-use through automatic encapsulation, adaptation to new platforms or languages, and optimization. We show through detailed examples how our approach can infer three modules in a representative application. Finally, we outline the broader paradigm and open research questions

Inhibition of Fatty Acid β-Oxidation by Fatty Acid Binding Protein 4 Induces Ferroptosis in HK2 Cells Under High Glucose Conditions

Background Ferroptosis, which is caused by an iron-dependent accumulation of lipid hydroperoxides, is a type of cell death linked to diabetic kidney disease (DKD). Previous research has shown that fatty acid binding protein 4 (FABP4) is involved in the regulation of ferroptosis in diabetic retinopathy. The present study was constructed to explore the role of FABP4 in the regulation of ferroptosis in DKD. Methods We first detected the expression of FABP4 and proteins related to ferroptosis in renal biopsies of patients with DKD. Then, we used a FABP4 inhibitor and small interfering RNA to investigate the role of FABP4 in ferroptosis induced by high glucose in human renal proximal tubular epithelial (HG-HK2) cells. Results In kidney biopsies of DKD patients, the expression of FABP4 was elevated, whereas carnitine palmitoyltransferase-1A (CP-T1A), glutathione peroxidase 4, ferritin heavy chain, and ferritin light chain showed reduced expression. In HG-HK2 cells, the induction of ferroptosis was accompanied by an increase in FABP4. Inhibition of FABP4 in HG-HK2 cells changed the redox state, sup-pressing the production of reactive oxygen species, ferrous iron (Fe2+), and malondialdehyde, increasing superoxide dismutase, and reversing ferroptosis-associated mitochondrial damage. The inhibition of FABP4 also increased the expression of CPT1A, reversed lipid deposition, and restored impaired fatty acid β-oxidation. In addition, the inhibition of CPT1A could induce ferroptosis in HK2 cells. Conclusion Our results suggest that FABP4 mediates ferroptosis in HG-HK2 cells by inhibiting fatty acid β-oxidation

A retrospective study of 23 cases with subacute combined degeneration

<p><i>Purpose</i>: To study retrospectively the diverse presentations, ancillary tests and neuroimaging in patients with subacute combined degeneration (SCD). <i>Methods</i>: Twenty-three Chinese patients with SCD were included in this study. The clinical presentations and laboratory data including comprehensive metabolic panel, serum folic acid, vitamin B12 levels, gastroscopy and images of spinal cord on magnetic resonance imaging (MRI) were evaluated. Rating scales for localizations of lesions and functional disabilities were used to define the severity of neurological impairment. <i>Results</i>: No difference was found between men and women in the age of disease onset. For most of the patients, sensory symptoms, oftentimes as initial symptoms, occurred earlier than motor symptoms. The signs of the disease were more obvious than the symptoms. Six patients had sensory deficit levels mimicking transverse myelopathy. Anemia was not always detected in our patients with SCD. Normal or even elevated serum levels of vitamin B12 were found in seven patients. Spinal cord lesions on MRI were observed in six patients and the clinical and neuroimaging findings were not necessarily consistent. <i>Conclusions</i>: The sensory symptoms occur earlier than the motor symptoms in SCD patients. SCD patients may have sensory deficit level. Normal or even elevated serum levels of vitamin B12 may occur in patients with SCD.</p

San-Huang-Xie-Xin-Tang constituents exert drug-drug interaction of mutual reinforcement at both pharmacodynamics and pharmacokinetic level: a review

Abstract Inflammatory disorders underlie varieties of human diseases. San-huang-xie-xin-tang (SHXXT), composed with Rhizoma Rhei (Rheum palmatum L.), Rhizoma Coptidis (Coptis chinensis Franch), and Radix Scutellaria (Scutellaria baicalensis Georgi), is a famous formula which has been widely used in the fight against inflammatory abnormalities. Mutual reinforcement is one of the basic theories of traditional Chinese medicine. Here this article reviewed and analyzed the recent research on (1) How the main constituents of SHXXT impact on inflammation-associated signaling pathway molecules. (2) The interaction between the main constituents and efflux pumps or intestinal transporters. The goal of this work was to,(1) Provide evidence to support the theory of mutual reinforcement. (2) Clarify the key targets of SHXXT and suggest which targets need further investigation.(3) Give advice for the clinical use of SHXXT to elevated the absorption of main constituents and eventually promote oral bioavailability. We search literatures in scientific databases with key words of ‘each main SHXXT constituent’, in combination with ‘each main inflammatory pathway target molecule’ or each main intestinal transporter, respectively. We report the effect of five main constituents on target molecules which lies in three main inflammatory signaling pathways, we as well investigate the interaction between constituents and intestinal transporter.We conclude,(1)The synergistic effect of constituents at both levels confirm the mutual reinforcement theory of TCM as it is proven in this work. (2) The effect of main constituents on downstream targets in nuclear need more further investigation. (3) Drug elevating the absorption of rhein, berberine and baicalein can be employed to promote oral bioavailability of SHXXT