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  • Author: Guang Gong x
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Mesh: A Supply Chain Solution with Locally Private Blockchain Transactions

Abstract

A major line of research on blockchains is geared towards enhancing the privacy of transactions through anonymity using generic non-interactive proofs. However, there is a good cluster of application scenarios where complete anonymity is not desirable and accountability is in fact required. In this work, we utilize non-interactive proofs of knowledge of elliptic curve discrete logarithms to present membership and verifiable encryption proof, which offers plausible anonymity when combined with the regular signing process of the blockchain transactions. The proof system requires no trusted setup, both its communication and computation complexities are linear in the number of set members, and its security relies on the discrete logarithm assumption. As a use-case for this scenario, we present Mesh which is a blockchain-based framework for supply chain management using RFIDs. Finally, the confidentiality of the transacted information is realized using a lightweight key chaining mechanism implemented on RFIDs. We formally define and prove the main security features of the protocol, and report on experiments for evaluating the performance of the modified transactions for this system.

Open access
Exploration of the main sites for the transformation of normal prion protein (PrPC) into pathogenic prion protein (PrPsc)

Abstract

Introduction: The functions and mechanisms of prion proteins (PrPC) are currently unknown, but most experts believe that deformed or pathogenic prion proteins (PrPSc) originate from PrPC, and that there may be plural main sites for the conversion of normal PrPC into PrPSc. In order to better understand the mechanism of PrPC transformation to PrPSc, the most important step is to determine the replacement or substitution site.

Material and Methods: BALB/c mice were challenged with prion RML strain and from 90 days post-challenge (dpc) mice were sacrificed weekly until all of them had been at 160 dpc. The ultra-structure and pathological changes of the brain of experimental mice were observed and recorded by transmission electron microscopy.

Results: There were a large number of pathogen-like particles aggregated in the myelin sheath of the brain nerves, followed by delamination, hyperplasia, swelling, disintegration, phagocytic vacuolation, and other pathological lesions in the myelin sheath. The aggregated particles did not overflow from the myelin in unstained samples. The phenomenon of particle aggregation persisted all through the disease course, and was the earliest observed pathological change.

Conclusion: It was deduced that the myelin sheath and lipid rafts in brain nerves, including axons and dendrites, were the main sites for the conversion of PrPC to PrPSc, and the PrPSc should be formed directly by the conversion of protein conformation without the involvement of nucleic acids.

Open access