151 research outputs found

    Spectrum Focused Frequency Adversarial Attacks for Automatic Modulation Classification

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    Artificial intelligence (AI) technology has provided a potential solution for automatic modulation recognition (AMC). Unfortunately, AI-based AMC models are vulnerable to adversarial examples, which seriously threatens the efficient, secure and trusted application of AI in AMC. This issue has attracted the attention of researchers. Various studies on adversarial attacks and defenses evolve in a spiral. However, the existing adversarial attack methods are all designed in the time domain. They introduce more high-frequency components in the frequency domain, due to abrupt updates in the time domain. For this issue, from the perspective of frequency domain, we propose a spectrum focused frequency adversarial attacks (SFFAA) for AMC model, and further draw on the idea of meta-learning, propose a Meta-SFFAA algorithm to improve the transferability in the black-box attacks. Extensive experiments, qualitative and quantitative metrics demonstrate that the proposed algorithm can concentrate the adversarial energy on the spectrum where the signal is located, significantly improve the adversarial attack performance while maintaining the concealment in the frequency domain.Comment: 6 pages, 9 figure

    Acetylation Regulates Gluconeogenesis by Promoting PEPCK1 Degradation via Recruiting the UBR5 Ubiquitin Ligase

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    Protein acetylation has emerged as a major mechanism in regulating cellular metabolism. Whereas most glycolytic steps are reversible, the reaction catalyzed by pyruvate kinase is irreversible and the reverse reaction requires phosphoenolpyruvate carboxykinase (PEPCK1) to commit for gluconeogenesis. Here we show that acetylation regulates the stability of the gluconeogenic rate limiting enzyme PEPCK1, thereby modulating cellular response to glucose. High glucose destabilizes PEPCK1 by stimulating its acetylation. PEPCK1 is acetylated by the P300 acetyltransferase and this acetylation stimulates the interaction between PEPCK1 and UBR5, a HECT domain containing E3 ubiquitin ligase, therefore promoting PEPCK1 ubiquitinylation and degradation. Conversely, SIRT2 deacetylates and stabilizes PEPCK1. These observations represent an example that acetylation targets a metabolic enzyme to a specific E3 ligase in response to metabolic condition changes. Given that increased levels of PEPCK is linked with type II diabetes, this study also identifies potential therapeutic targets for diabetes

    Plasma exosomal miR-320d, miR-4479, and miR-6763-5p as diagnostic biomarkers in epithelial ovarian cancer

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    BackgroundExosomal miRNA had been proved as the promising biomarkers for multiple cancers including epithelial ovarian cancer (EOC). This study aimed to validate the diagnostic accuracy of exosomal miR-320d, miR-4479, and miR-6763-5p for EOC.Materials and methodsExosomes isolated from the plasma by ultracentrifugation were verified using TEM, qNano and western blot. MiRNAs sequencing was used to screen out the differential exosomal miRNAs and miR-320d, miR-4479, and miR-6763-5p were selected as candidates, which were further verified by RT-qPCR in 168 healthy donors and 161 primary EOC patients. Besides, the diagnostic accuracy of these three exosomal miRNAs were evaluated using the receiver operating characteristic curve (ROC).ResultsMiRNAs sequencing revealed 95 differential exosomal miRNAs between EOC patients and healthy donors. Subsequently, exosomal miR-320d, miR-4479, and miR-6763-5p were significantly down regulated in EOC patients compared with healthy controls and benign patients. More importantly, these three miRNAs could serve as circulating diagnostics biomarkers for EOC, possessing areas under the curve (AUC) of 0.6549, 0.7781, and 0.6834, respectively. Moreover, these three exosomal miRNAs levels were closely associated with lymph node metastasis, meanwhile exosomal miR-320d and miR-4479 expression was related to tumor stage.ConclusionExosomal miR-320d, miR-4479, and miR-6763-5p might serve as potential biomarkers for EOC

    A clinical Pseudomonas juntendi strain with blaIMP−1 carried by an integrative and conjugative element in China

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    ObjectiveTo precisely determine the species of a carbapenem-resistant Pseudomonas strain 1809276 isolated from the urine of a Chinese patient and analyze its integrative and conjugative element (ICE) 1276 formation mechanism.MethodsSingle-molecule real-time (SMRT) sequencing was carried out on strain 18091276 to obtain the complete chromosome and plasmid (pCN1276) sequences, and average nucleotide identity (ANI) was used for precise species identification. The ICEs in GenBank with the same integrase structure as ICE 1276 were aligned. At the same time, the transfer ability of blaIMP−1 and the antibiotic sensitivity of Pseudomonas juntendi 18091276 were tested.ResultsThis bacterium was P. juntendi, and its drug resistance mechanism is the capture of the accA4' gene cassette by the Tn402-like type 1 integron (IntI1-blaIMP−1) to form In1886 before its capture by the ΔTn4662a-carrying ICE 1276. The acquisition of blaIMP−1 confers carbapenem resistance to P. juntendi 18091276.ConclusionThe formation of blaIMP−1-carrying ICE 1276, its further integration into the chromosomes, and transposition and recombination of other elements promote bacterial gene accumulation and transmission

    Recombinant Expression, Purification, and Functional Characterisation of Connective Tissue Growth Factor and Nephroblastoma-Overexpressed Protein

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    The CCN family of proteins, especially its prominent member, the Connective tissue growth factor (CTGF/CCN2) has been identified as a possible biomarker for the diagnosis of fibrotic diseases. As a downstream mediator of TGF-β1 signalling, it is involved in tissue scarring, stimulates interstitial deposition of extracellular matrix proteins, and promotes proliferation of several cell types. Another member of this family, the Nephroblastoma-Overexpressed protein (NOV/CCN3), has growth-inhibiting properties. First reports further suggest that these two CCN family members act opposite to each other in regulating extracellular matrix protein expression and reciprocally influence their own expression when over-expressed. We have established stable HEK and Flp-In-293 clones as productive sources for recombinant human CCN2/CTGF. In addition, we generated an adenoviral vector for recombinant expression of rat NOV and established protocols to purify large quantities of these CCN proteins. The identity of purified human CCN2/CTGF and rat CCN3/NOV was proven by In-gel digest followed by ESI-TOF/MS mass spectrometry. The biological activity of purified proteins was demonstrated using a Smad3-sensitive reporter gene and BrdU proliferation assay in permanent cell line EA•hy 926 cells. We further demonstrate for the first time that both recombinant CCN proteins are N-glycosylated

    Stressing the Ubiquitin-Proteasome System without 20S Proteolytic Inhibition Selectively Kills Cervical Cancer Cells

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    Cervical cancer cells exhibit an increased requirement for ubiquitin-dependent protein degradation associated with an elevated metabolic turnover rate, and for specific signaling pathways, notably HPV E6-targeted degradation of p53 and PDZ proteins. Natural compounds with antioxidant properties including flavonoids and triterpenoids hold promise as anticancer agents by interfering with ubiquitin-dependent protein degradation. An increasing body of evidence indicates that their α-β unsaturated carbonyl system is the molecular determinant for inhibition of ubiquitin-mediated protein degradation up-stream of the catalytic sites of the 20S proteasome. Herein we report the identification and characterization of a new class of chalcone-based, potent and cell permeable chemical inhibitors of ubiquitin-dependent protein degradation, and a lead compound RAMB1. RAMB1 inhibits ubiquitin-dependent protein degradation without compromising the catalytic activities of the 20S proteasome, a mechanism distinct from that of Bortezomib. Treatment of cervical cancer cells with RAMB1 triggers unfolded protein responses, including aggresome formation and Hsp90 stabilization, and increases p53 steady state levels. RAMB1 treatment results in activation of lysosomal-dependent degradation pathways as a mechanism to compensate for increasing levels of poly-ubiquitin enriched toxic aggregates. Importantly, RAMB1 synergistically triggers cell death of cervical cancer cells when combined with the lysosome inhibitor Chloroquine

    Nanotechnology in agriculture, livestock, and aquaculture in China. A review

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    Introduction of Rural Ecological Environment and Circular Economy Development Mode of Eco-agriculture and Forestry

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    Major causes of ecological environment situation and rural environment issues in the construction of new socialist countryside in China are analyzed. Two necessities of introducing circular economy development mode of eco-agriculture and forestry into the construction of new socialist countryside are expatiated. One is the needs of the rural eco-environmental situation, and the other is to realize the fundamental change of agricultural growth mode. Specific characteristics, existing foundation and current resistance of the circular economy of eco-agriculture and forestry are studied. Major principles in introducing circular economy mode of eco-agriculture and forestry into the construction of new socialist countryside are presented. Support system for constructing the circular economy mode of eco-agriculture and forestry is discussed, including the improved government function and regulatory mechanism, marketing organization, farmers professional cooperative organization, leading enterprise, circular economic market system of eco-agriculture and forestry, and human resources. Taking Huaping County, Lijiang City, Yunnan Province, China as an example, “919” circular economic model in this county and its development result are analyzed

    Introduction of Rural Ecological Environment and Circular Economy Development Mode of Eco-agriculture and Forestry

    No full text
    Major causes of ecological environment situation and rural environment issues in the construction of new socialist countryside in China are analyzed. Two necessities of introducing circular economy development mode of eco-agriculture and forestry into the construction of new socialist countryside are expatiated. One is the needs of the rural eco-environmental situation, and the other is to realize the fundamental change of agricultural growth mode. Specific characteristics, existing foundation and current resistance of the circular economy of eco-agriculture and forestry are studied. Major principles in introducing circular economy mode of eco-agriculture and forestry into the construction of new socialist countryside are presented. Support system for constructing the circular economy mode of eco-agriculture and forestry is discussed, including the improved government function and regulatory mechanism, marketing organization, farmers professional cooperative organization, leading enterprise, circular economic market system of eco-agriculture and forestry, and human resources. Taking Huaping County, Lijiang City, Yunnan Province, China as an example, “919†circular economic model in this county and its development result are analyzed.Ecological environment, Circular economy, Development, Introduction, China, Community/Rural/Urban Development, Environmental Economics and Policy, Resource /Energy Economics and Policy,
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