56 research outputs found

    The art of defense: letting networks fool the attacker

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    Some deep neural networks are invariant to some input transformations, such as Pointnet is permutation invariant to the input point cloud. In this paper, we demonstrated this property could be powerful in defense of gradient-based attacks. Specifically, we apply random input transformation which is invariant to the networks we want to defend. Extensive experiments demonstrate that the proposed scheme defeats various gradient-based attackers in the targeted attack setting, and breaking the attack accuracy into nearly zero. Our code is available at: {\footnotesize{\url{https://github.com/cuge1995/IT-Defense}}}

    Experimental and Simulation Identification of Xanthohumol as an Inhibitor and Substrate of ABCB1

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    Xanthohumol (XN) is a well-known prenylated flavonoid found in Humulus lupulus L. It is involved in several pharmacological activities, including the sensitization of doxorubicin-resistant breast cancer (MCF-7/ADR) cells to doxorubicin (DOX) through a reduction in cell viability and stemness. In the present study, we revealed another mechanism to further explain the reverse of the drug resistance of XN. In the MCF-7/ADR cell line, we found that XN inhibited the efflux functions of ATP-binding cassette subfamily B member 1 (ABCB1). We also observed that XN was a substrate of ABCB1 and stimulated its ATPase activity. Moreover, our results revealed that XN showed a synergic effect with the ABCB1 substrate colchicine (COL) in the MCF-7/ADR cell line. Further, we showed that XN bound to the central transmembrane domain (TMD) site, overlapping with the DOX binding site. This mechanism was supported by molecular modeling and simulation data, which revealed that XN bound to the ABCB1 transmembrane domain, where doxorubicin also binds, and its binding affinity was stronger than that of doxorubicin, resulting in less protein and ligand position fluctuation. These results support the XN-induced reversal of drug resistance via the inhibition of ABCB1-mediated transport of doxorubicin, stimulating ABCB1 ATPase activity and acting as a substrate of ABCB1

    Effect of high salinity on cell growth and protein production of Antarctic ice microalgae Chlamydomonas sp. ICE-L

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    Antarctic ice microalgae Chlamydomonas sp. ICE-L can survive and thrive in Antarctic sea ice. In this study, Chlamydomonas sp. ICE-L could survive at the salinity of 132% NaCl. SDS-PAGE showed that the density of 2 bands (26 and 36 kD) decreased obviously at the salinity of 99% NaCl compared to at the salinity of 33% NaCl. The soluble proteins in Chlamydomonas sp. ICE-L grown under salinity of 33% and 99% NaCl were compared by 2-D gel electro-phoresis. After shocking with high salinity, 8 protein spots were found to disappear, and the density of 28 protein spots decreased. In addition, 19 protein spots were enhanced or induced, including one new peptide(51kD).The changes of proteins might be correlated with the resistance for Chlamydomonas sp. ICE-L to high salinity
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