Deep neural networks (DNN) have achieved unprecedented success in numerous machine learning tasks in various domains. However, the existence of adversarial examples raises our concerns in adopting ...deep learning to safety-critical applications. As a result, we have witnessed increasing interests in studying attack and defense mechanisms for DNN models on different data types, such as images, graphs and text. Thus, it is necessary to provide a systematic and comprehensive overview of the main threats of attacks and the success of corresponding countermeasures. In this survey, we review the state of the art algorithms for generating adversarial examples and the countermeasures against adversarial examples, for three most popular data types, including images, graphs and text.
Colloidal carbon sphere nanoreactors have been explored extensively as a class of versatile materials for various applications in energy storage, electrochemical conversion, and catalysis, due to ...their unique properties such as excellent electrical conductivity, high specific surface area, controlled porosity and permeability, and surface functionality. Here, the latest updated research on colloidal carbon sphere nanoreactor, in terms of both their synthesis and applications, is summarized. Various synthetic strategies are first discussed, including the hard template method, the soft template method, hydrothermal carbonization, the microemulsion polymerization method, and extension of the Stöber method. Then, the functionalization of colloidal carbon sphere nanoreactors, including the nanoengineering of compositions and the surface features, is discussed. Afterward, recent progress in the major applications of colloidal carbon sphere nanoreactors, in the areas of energy storage, electrochemical conversion, and catalysis, is presented. Finally, the perspectives and challenges for future developments are discussed in terms of controlled synthesis and functionalization of the colloidal carbon sphere nanoreactors with tunable structure, and the composition and properties that are desirable for practical applications.
Colloidal carbon spheres with tailored pore sizes, heteroatoms, and surface functionalities are considered as promising materials in a number of research areas such as batteries, catalysis, water and air purification, and adsorption. The latest work, mainly focusing on synthetic approaches with optimized properties of nanoporous carbon spheres toward electrochemical storage, conversion, and catalysis, is systematically summarized.
Understanding the molecular mechanisms regulating the maintenance and destruction of intervertebral disc may lead to the development of new therapies for intervertebral disc degeneration (IDD). Here ...we present evidence from miRNA microarray analyses of clinical data sets along with in vitro and in vivo experiments that miR-141 is a key regulator of IDD. Gain- and loss-of-function studies show that miR-141 drives IDD by inducing nucleus pulposus (NP) apoptosis. Furthermore, miR-141 KO in mice attenuated spontaneous and surgically induced IDD. Mechanistically, miR-141 promotes IDD development by targeting and depleting SIRT1, a negative regulator of NF-κB pathway. Therapeutically, upregulation or downregulation of miR-141 by nanoparticle delivery in IDD model aggravated or alleviated experimental IDD, respectively. Our findings reveal a novel mechanism by which miR-141, in part, promotes IDD progression by interacting with SIRT1/NF-κB pathway. Blockade of miR-141 in vivo may serve as a potential therapeutic approach in the treatment of IDD.
Hypoxia and the acidic microenvironment play a vital role in tumor metastasis and angiogenesis, generally compromising the chemotherapeutic efficacy. This provides a tantalizing angle for the design ...of platinum(IV) prodrugs for the effective and selective killing of solid tumors. Herein, two carbonic anhydrase IX (CAIX)‐targeting platinum(IV) prodrugs have been developed, named as CAIXplatins. Based on their strong affinity for and inhibition of CAIX, CAIXplatins can not only overcome hypoxia and the acidic microenvironment, but also inhibit metabolic pathways of hypoxic cancer cells, resulting in a significantly enhanced therapeutic effect on hypoxic MDA‐MB‐231 tumors both in vitro and in vivo compared with cisplatin/oxaliplatin, accompanied with excellent anti‐metastasis and anti‐angiogenesis activities. Furthermore, the cancer selectivity indexes of CAIXplatins are 70–90 times higher than those of cisplatin/oxaliplatin with effectively alleviated side‐effects.
Tumor microenvironment and metabolism regulation can be achieved by targeting carbonic anhydrase IX with platinum(IV) prodrugs, termed CAIXplatins. This strategy could be used to treat hypoxic and aggressive tumors. The advantages of CAIXplatins in comparison to cisplatin/oxaliplatin include the greatly increased cancer selectivity index, enhanced therapeutic efficiency, reduced level of side‐effects, as well as the excellent anti‐angiogenesis activity.
Thermoelectric Mg3+δ(Sb, Bi)2 Zintls have attracted significant attention because of their high‐performing, eco‐friendly, and cost‐effective features, but their thermoelectric properties still need ...improvement for application to practical devices. Here an outstanding ZT of ≈1.87 at 773 K and a high average ZT of ≈1.2 in n‐type Y‐doped Mg3.2Sb1.5Bi0.49Se0.01 are reported, both of which rank as top values among the reported literature. First‐principles calculations indicate that substituting the Mg site with Y shifts the Fermi level into the conduction band and simultaneously narrows the bandgap, both strengthening the n‐type semiconducting feature and boosting the electron carrier density of Mg3.2Sb1.5Bi0.49Se0.01. A high power factor of ≈21.4 µW cm–1 K–2 is achieved at 773 K in Mg3.18Y0.02Sb1.5Bi0.49Se0.01, benefiting from the rationally tuned carrier density of ≈7.7 × 1019 cm–3 at this temperature. In addition, the doped Ys act as point defects to cause significant lattice distortions and strains, confirmed by comprehensive micro/nanostructure characterizations. These lattice imperfections suppress the lattice thermal conductivity to ≈0.41 W m–1 K–1 at 773 K, leading to such a high ZT. Furthermore, a high energy conversion efficiency of ≈13.8% is predicted by a temperature gradient of 450 K, indicating a great potential to be applied to practical devices for mid‐temperature applications.
A new strategy of Y doping and nanostructuring is designed for achieving outstanding thermoelectric performance in Mg3.2Sb1.5Bi0.49Se0.01‐based Zintls with a peak ZT of ≈1.87 at 773 K, a high average ZT of ≈1.2, and a high energy conversion efficiency of ≈13.8% predicted by a temperature gradient of 450 K.
G‐quadruplex DNA show structural polymorphism, leading to challenges in the use of selective recognition probes for the accurate detection of G‐quadruplexes in vivo. Herein, we present a tripodal ...cationic fluorescent probe, NBTE, which showed distinguishable fluorescence lifetime responses between G‐quadruplexes and other DNA topologies, and fluorescence quantum yield (Φf) enhancement upon G‐quadruplex binding. We determined two NBTE‐G‐quadruplex complex structures with high Φf values by NMR spectroscopy. The structures indicated NBTE interacted with G‐quadruplexes using three arms through π–π stacking, differing from that with duplex DNA using two arms, which rationalized the higher Φf values and lifetime response of NBTE upon G‐quadruplex binding. Based on photon counts of FLIM, we detected the percentage of G‐quadruplex DNA in live cells with NBTE and found G‐quadruplex DNA content in cancer cells is 4‐fold that in normal cells, suggesting the potential applications of this probe in cancer cell detection.
G4 imaging: A tripodal cationic fluorescence probe, NBTE, was used for the visualization (based on fluorescence lifetime) and quantification (based on photon counts) of G‐quadruplex DNA in live cells by fluorescence lifetime imaging microscopy (FLIM). Structural studies provided a structural basis for the DNA‐topology‐based fluorescence response of NBTE.
During autophagy, the intracellular components are captured in autophagosomes and delivered to lysosomes for degradation and recycling. Changes in lysosomal trafficking and contents are key events in ...the regulation of autophagy, which has been implicated in many physiological and pathological processes. In this work, two iridium(III) complexes (LysoIr1 and LysoIr2) are developed as theranostic agents to monitor autophagic lysosomes. These complexes display lysosome‐activated phosphorescence and can specifically label lysosomes with high photostability. Simultaneously, they can induce autophagy potently without initiating an apoptosis response. We demonstrate that LysoIr2 can effectively implement two functions, namely autophagy induction and lysosomal tracking, in the visualization of autophagosomal–lysosomal fusion. More importantly, they display strong two‐photon excited fluorescence (TPEF), which is favorable for live cell imaging and in vivo applications.
Kill Two Birds with One Stone: Two iridium(III) complexes can specifically image lysosomes and induce an autophagic response in live cells. The combination of these two intriguing properties makes them ideal theranostic agents to track lysosomal changes during autophagic processes. Additionally, these complexes display strong two‐photon excited fluorescence, which is favorable for live cell imaging and in vivo applications.
The development and malignancy of cancer cells are closely related to the changes of the epigenome. In this work, a mitochondria‐targeted rhenium(I) complex (DFX‐Re3), integrating the clinical iron ...chelating agent deferasirox (DFX), has been designed. By relocating iron to the mitochondria and changing the key metabolic species related to epigenetic modifications, DFX‐Re3 can elevate the methylation levels of histone, DNA, and RNA. As a consequence, DFX‐Re3 affects the events related to apoptosis, RNA polymerases, and T‐cell receptor signaling pathways. Finally, it is shown that DFX‐Re3 induces immunogenic apoptotic cell death and exhibits potent antitumor activity in vivo. This study provides a new approach for the design of novel epigenetic drugs that can recode the cancer epigenome by intervening in mitochondrial metabolism and iron homeostasis.
Reported here is a mitochondria‐targeted ReI complex, DFX‐Re3, that can relocate iron to the mitochondria and change the metabolites related to epigenetics. DFX‐Re3 can elevate the methylation levels of histone/DNA/RNA, affect RNA polymerase activities, and induce immunogenic apoptosis. This study provides a new approach to the design of epigenetic drugs for recoding the cancer epigenome by intervening in mitochondrial metabolism and iron homeostasis.
ABSTRACT
Xanthomonas is a well-studied genus of bacterial plant pathogens whose members cause a variety of diseases in economically important crops worldwide. Genomic and functional studies of these ...phytopathogens have provided significant understanding of microbial-host interactions, bacterial virulence and host adaptation mechanisms including microbial ecology and epidemiology. In addition, several strains of Xanthomonas are important as producers of the extracellular polysaccharide, xanthan, used in the food and pharmaceutical industries. This polymer has also been implicated in several phases of the bacterial disease cycle. In this review, we summarise the current knowledge on the infection strategies and regulatory networks controlling virulence and adaptation mechanisms from Xanthomonas species and discuss the novel opportunities that this body of work has provided for disease control and plant health.
Here, we discuss the current knowledge surrounding regulatory networks and systems that control virulence and adaption mechanisms in Xanthomonas species. Additionally, we detail how study of these pathogens has provided novel opportunities for disease control and plant health.
The reinforcing effects of highly effective flame retardant magnesium hydroxide (FMX) content on the tensile and flexural properties of filled polypropylene (PP) composites were investigated within ...the FMX weight fraction range from 5 to 60 wt%. It was found that the Young's modulus and flexural modulus increased approximately linearly while the tensile yield strength and tensile fracture strength decreased slightly with increasing the FMX weight fraction. When the FMX weight fraction was lower than 20%, the tensile elongation at break decreased considerably, and then decreased slightly; the flexural strength increased when the FMX weight fraction was lower than 30%, and then decreased slightly. The tensile properties increased with increasing rate of tension. Moreover, the tensile yield strength of the composites was estimated using an equation proposed in previous work, and good agreement was shown between the predicted and the measured data.
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