19 research outputs found
Physical Adversarial Attack meets Computer Vision: A Decade Survey
Although Deep Neural Networks (DNNs) have achieved impressive results in
computer vision, their exposed vulnerability to adversarial attacks remains a
serious concern. A series of works has shown that by adding elaborate
perturbations to images, DNNs could have catastrophic degradation in
performance metrics. And this phenomenon does not only exist in the digital
space but also in the physical space. Therefore, estimating the security of
these DNNs-based systems is critical for safely deploying them in the real
world, especially for security-critical applications, e.g., autonomous cars,
video surveillance, and medical diagnosis. In this paper, we focus on physical
adversarial attacks and provide a comprehensive survey of over 150 existing
papers. We first clarify the concept of the physical adversarial attack and
analyze its characteristics. Then, we define the adversarial medium, essential
to perform attacks in the physical world. Next, we present the physical
adversarial attack methods in task order: classification, detection, and
re-identification, and introduce their performance in solving the trilemma:
effectiveness, stealthiness, and robustness. In the end, we discuss the current
challenges and potential future directions.Comment: 32 pages. Under Revie
Loss of spindle assembly checkpoint–mediated inhibition of Cdc20 promotes tumorigenesis in mice
Genomic instability is a hallmark of human cancers. Spindle assembly checkpoint (SAC) is a critical cellular mechanism that prevents chromosome missegregation and therefore aneuploidy by blocking premature separation of sister chromatids. Thus, SAC, much like the DNA damage checkpoint, is essential for genome stability. In this study, we report the generation and analysis of mice carrying a Cdc20 allele in which three residues critical for the interaction with Mad2 were mutated to alanine. The mutant Cdc20 protein (AAA-Cdc20) is no longer inhibited by Mad2 in response to SAC activation, leading to the dysfunction of SAC and aneuploidy. The dysfunction could not be rescued by the additional expression of another Cdc20 inhibitor, BubR1. Furthermore, we found that Cdc20AAA/AAA mice died at late gestation, but Cdc20+/AAA mice were viable. Importantly, Cdc20+/AAA mice developed spontaneous tumors at highly accelerated rates, indicating that the SAC-mediated inhibition of Cdc20 is an important tumor-suppressing mechanism
Janus Kinase Signaling: Oncogenic Criminal of Lymphoid Cancers
10.3390/cancers13205147CANCERS132
Cardioprotection of CAPE-oNO2 against myocardial ischemia/reperfusion induced ROS generation via regulating the SIRT1/eNOS/NF-κB pathway in vivo and in vitro
Caffeic acid phenethyl ester (CAPE) could ameliorate myocardial ischemia/reperfusion injury (MIRI) by various mechanisms, but there hadn’t been any reports on that CAPE could regulate silent information regulator 1 (SIRT1) and endothelial nitric oxide synthase (eNOS) to exert cardioprotective effect. The present study aimed to investigate the cardioprotective potential of caffeic acid o-nitro phenethyl ester (CAPE-oNO2) on MIRI and the possible mechanism based on the positive control of CAPE. The SD rats were subjected to left coronary artery ischemia /reperfusion (IR) and the H9c2 cell cultured in hypoxia/reoxygenation (HR) to induce the MIRI model. Prior to the procedure, vehicle, CAPE or CAPE-oNO2 were treated in the absence or presence of a SIRT1 inhibitor nicotinamide (NAM) and an eNOS inhibitor Nω-nitro-L-arginine methyl ester (L-NAME). In vivo, CAPE and CAPE-oNO2 conferred a cardioprotective effect as shown by reduced myocardial infarct size, cardiac marker enzymes and structural abnormalities. From immunohistochemical and sirius red staining, above two compounds ameliorated the TNF-α release and collagen deposition of IR rat hearts. They could agitate SIRT1 and eNOS expression, and consequently enhance NO release and suppress NF-κB signaling, to reduce the malondialdehyde content and cell necrosis. In vitro, they could inhibit HR-induced H9c2 cell apoptosis and ROS generation by activating SIRT1/eNOS pathway and inhabiting NF-κB expression. Emphatically, CAPE-oNO2 presented the stronger cardioprotection than CAPE both in vivo and in vitro. However, NAM and L-NAME eliminated the CAPE-oNO2-mediated cardioprotection by restraining SIRT1 and eNOS expression, respectively. It suggested that CAPE-oNO2 ameliorated MIRI by suppressing the oxidative stress, inflammatory response, fibrosis and necrocytosis via the SIRT1/eNOS/NF-κB pathway
One-Pot Synthesis of Ginsenoside Rh2 and Bioactive Unnatural Ginsenoside by Coupling Promiscuous Glycosyltransferase from <i>Bacillus subtilis</i> 168 to Sucrose Synthase
Ginsenosides,
the major effective ingredients of <i>Panax
ginseng</i>, exhibit various biological properties. UDP-glycosyltransferase
(UGT)-mediated glycosylation is the last biosynthetic step of ginsenosides
and contributes to their immense structural and functional diversity.
In this study, UGT Bs-YjiC from <i>Bacillus subtilis</i> 168 was demonstrated to transfer a glucosyl moiety to the free C3-OH
and C12-OH of protopanaxadiol (PPD) and PPD-type ginsenosides to synthesize
natural and unnatural ginsenosides. In vitro assays showed that unnatural
ginsenoside F12 (3-<i>O</i>-β-d-glucopyranosyl-12-<i>O</i>-β-d-glucopyranosyl-20(<i>S</i>)-protopanaxadiol) exhibited remarkable activity against diverse
human cancer cell lines. A one-pot reaction by coupling Bs-YjiC to
sucrose synthase (SuSy) was performed to regenerate UDP-glucose from
sucrose and UDP. With PPD as the aglycon, an unprecedented high yield
of ginsenosides F12 (3.98 g L<sup>–1</sup>) and Rh2 (0.20 g
L<sup>–1</sup>) was obtained by optimizing the conversion conditions.
This study provides an efficient approach for the biosynthesis of
ginsenosides using a UGT-SuSy cascade reaction