Coronavirus Papain-like Proteases Negatively Regulate Antiviral Innate Immune Response through Disruption of STING-Mediated Signaling

Viruses have evolved elaborate mechanisms to evade or inactivate the complex system of sensors and signaling molecules that make up the host innate immune response. Here we show that human coronavirus (HCoV) NL63 and severe acute respiratory syndrome (SARS) CoV papain-like proteases (PLP) antagonize innate immune signaling mediated by STING (stimulator of interferon genes, also known as MITA/ERIS/MYPS). STING resides in the endoplasmic reticulum and upon activation, forms dimers which assemble with MAVS, TBK-1 and IKKε, leading to IRF-3 activation and subsequent induction of interferon (IFN). We found that expression of the membrane anchored PLP domain from human HCoV-NL63 (PLP2-TM) or SARS-CoV (PLpro-TM) inhibits STING-mediated activation of IRF-3 nuclear translocation and induction of IRF-3 dependent promoters. Both catalytically active and inactive forms of CoV PLPs co-immunoprecipitated with STING, and viral replicase proteins co-localize with STING in HCoV-NL63-infected cells. Ectopic expression of catalytically active PLP2-TM blocks STING dimer formation and negatively regulates assembly of STING-MAVS-TBK1/IKKε complexes required for activation of IRF-3. STING dimerization was also substantially reduced in cells infected with SARS-CoV. Furthermore, the level of ubiquitinated forms of STING, RIG-I, TBK1 and IRF-3 are reduced in cells expressing wild type or catalytic mutants of PLP2-TM, likely contributing to disruption of signaling required for IFN induction. These results describe a new mechanism used by CoVs in which CoV PLPs negatively regulate antiviral defenses by disrupting the STING-mediated IFN induction

Effect of azoxystrobin fungicide on the physiological and biochemical indices and ginsenoside contents of ginseng leaves

Background: The impact of fungicide azoxystrobin, applied as foliar spray, on the physiological and biochemical indices and ginsenoside contents of ginseng was studied in ginseng (Panax ginseng Mey. cv. “Ermaya”) under natural environmental conditions. Different concentrations of 25% azoxystrobin SC (150 g a.i./ha and 225 g a.i./ha) on ginseng plants were sprayed three times, and the changes in physiological and biochemical indices and ginsenoside contents of ginseng leaves were tested. Methods: Physiological and biochemical indices were measured using a spectrophotometer (Shimadzu UV-2450). Every index was determined three times per replication. Extracts of ginsenosides were analyzed by HPLC (Shimadzu LC20-AB) utilizing a GL-Wondasil C18 column. Results: Chlorophyll and soluble protein contents were significantly (p=0.05) increased compared with the control by the application of azoxystrobin. Additionally, activities of superoxide dismutase, catalase, ascorbate peroxidase, peroxidase, and ginsenoside contents in azoxystrobin-treated plants were improved, and malondialdehyde content and O2− contents were reduced effectively. Azoxystrobin treatments to ginseng plants at all growth stages suggested that the azoxystrobin-induced delay of senescence was due to an enhanced antioxidant enzyme activity protecting the plants from harmful active oxygen species. When the dose of azoxystrobin was 225 g a.i./ha, the effect was more significant. Conclusion: This work suggested that azoxystrobin played a role in delaying senescence by changing physiological and biochemical indices and improving ginsenoside contents in ginseng leaves. Keywords: azoxystrobin, ginsenoside contents, leaves, Panax ginseng, physiological and biochemical indice

Investigating the Influences of the Adsorbed Species on Catalytic Activity for Hydrogen Oxidation Reaction in Alkaline Electrolyte

Catalysts for hydrogen oxidation reaction (HOR) in alkaline electrolyte are important for anion exchange membrane fuel cells. Understanding the role of OH^– during the HOR catalytic process in alkaline electrolyte is essential to design highly active HOR catalysts. Here, we attempt to isolate the influence of OH^– by using surface-controlled Pt based nanoparticles as the model catalysts. With a comparison of the HOR activity between PtNi nanoparticles and acid washed PtNi nanoparticles, which have almost the same hydrogen binding energies but much different OH binding energies, it was found that the HOR activity in alkaline electrolyte is not mainly controlled by the OH adsorption. Therefore, a bifunctional catalyst promoting OH adsorption may not useful for HOR in alkaline electrolyte. Tuning the hydrogen binding energy was found to be an efficient way to enhance the HOR activity, and making Pt base alloy is a reasonable way to tune the hydrogen binding energies

Nanometer Titanium Dioxide Mediated High Efficiency Photodegradation of Fluazifop-p-Butyl

The widespread use of fluazifop-p-butyl (FPB) contributes to its presence in the environment. Considering the ecological risks of FPB residues in the environment, the anatase nanometer titanium dioxide (nano-TiO2) mediated photocatalytic degradation of FPB was studied by smearing FPB and nano-TiO2 together on a glass plane; illumination, trimethylsilane derivatization of photolysis products, high performance liquid chromatography (HPLC) quantitative analysis and gas chromatograph-mass spectrometer (GC-MS) identification were used. Results showed that the first order dynamic model could describe the photodegradation of FPB by nano-TiO2 mediated, and the photodegradation and photosensitization rates were found to be positively correlated with the dose of nano-TiO2 at lower dose ranges. It is noticeable that a strong photosensitization effect was exhibited on degradation of FPB, not only under high-pressure mercury lamps, but also simulated sunlight (xenon lamp light). Ultimately, twelve main photolytic products were reasonably speculated, whilst five photolysis pathways were proposed. These results together suggest that nano-TiO2 can be used as an effective photosensitizer to accelerate FPB photolysis

Research on precise detection method of personnel in shearer operation area

The current intelligent shearer has the functions of three-dimensional positioning, memory cutting and remote monitoring, but it lacks the detection and early warning protection function of personnel entering the shearer operation area by mistake. Therefore, the precise detection of personnel is one of the key problems to be solved urgently. Affected by the low illumination and complex working conditions of fully mechanized working face, the application of active anti-collision warning technology for coal mine electromechanical equipment based on laser, radio frequency, ultrasonic and other sensors is limited, and the anti-collision technology based on visible light sensor cannot meet the requirements of accuracy and stability. The system architecture of precise detection of personnel in shearer operation area based on infrared thermal imaging technology is built, and then the precise detection method of personnel is proposed. Aiming at the high intensity and uneven characteristics of the infrared image noise in fully mechanized working face, an improved multi-layer guided filter model based on Gauss mask-code is used to filter out infrared image noise effectively and retain the edge information. The moving foreground target motion information under dynamic background is extracted by optical flow method that based on Lucas-Kanade. The intuitionistic fuzzy C-means clustering algorithm based on the weight of local image information is used to segment the infrared image information of the shearer operation area so as to obtain the position information of the moving target. Based on the morphological weighted voting method, the extraction results of the moving target motion information and the infrared image information segmentation results are fused to realize the precise detection of personnel in the shearer operation area. The underground industrial test is carried out in 21208 fully mechanized working face of Gengcun Coal Mine. The results show that the average tracking deviation of the precise detection method for personnel in the shearer operation area is 0.106 5 pixel, the average overlap ratio is 96.10%, and the average single processing time is 0.490 8 s, which meet the needs of field application

Determination of the Novel Insecticide Flupyradifurone and Its Two Metabolites in Traditional Chinese Herbal Medicines Using Modified QuEChERS and High-Performance Liquid Chromatography-Tandem Mass Spectrometry

In this study, an analytical method for the simultaneous determination of the novel insecticide flupyradifurone and its two metabolites in a variety of traditional Chinese herbal medicines was developed for the first time using high-performance liquid chromatography-tandem mass spectrometry. A simple and efficient method using dispersive solid-phase extraction was employed for the pretreatment of the samples. Several extractions and cleanup strategies were evaluated. The recoveries (n = 15) of flupyradifurone and its metabolites at three spiking levels were in the range 71.3%–101.7%, with corresponding intraday and interday relative standard deviations of 1.1%–14.8%. The limits of quantitation were 0.01 mg/kg for flupyradifurone and 0.1 mg/kg for its two metabolites. Overall, our developed method was sensitive and reliable for the fast screening of flupyradifurone and its two metabolites in traditional Chinese herbal medicine samples

Semi-automated landslide inventory mapping from bitemporal aerial photographs using change detection and level set method

Landslide inventory mapping (LIM) is an increasingly important research topic in remote sensing and natural hazards. Past studies achieve LIM mainly using on-screen interpretation of aerial photos, and little attention has been paid to developing more automated methods. In recent years, the use of multitemporal remote sensing images makes it possible to map landslides semi-automatically. Although numerous methods have been proposed, only a few methods are competent for some specific situations and there is large room for improvement in their degree of automation. For these reasons, a semi-automated approach is proposed for reliable and accurate LIM from bitemporal aerial orthophotos. Specifically, it consists of two principal steps: 1) change detection-based thresholding (CDT) and 2) level set evolution (LSE). CDT is mainly used to generate the initial zero-level curve (ZLC) for LSE, thus automating the proposed method considerably. It includes three substeps: 1) generating difference image (DI) using change vector analysis (CVA), 2) detecting landslide candidates using a thresholding method, and 3) removing errors using morphology operations. Then, landslide boundaries are detected using two types of LSE, i.e., edge-based LSE (ELSE) and region-based LSE (RLSE). Finally, the effectiveness and advantages of the proposed methods are corroborated by a series of experiments. Given its efficiency and accuracy, it can be applied to rapid responses of natural hazards. This study is the first attempt to apply LSE to LIM from bitemporal remote sensing images

Dissipation, Processing Factors and Dietary Risk Assessment for Flupyradifurone Residues in Ginseng

The massive use of pesticides has brought great risks to food and environmental safety. It is necessary to develop reliable analytical methods and evaluate risks through monitoring studies. Here, a method was used for the simultaneous determination of flupyradifurone (FPF) and its two metabolites in fresh ginseng, dried ginseng, ginseng plants, and soil. The method exhibited good accuracy (recoveries of 72.8–97.5%) and precision (relative standard deviations of 1.1–8.5%). The field experiments demonstrated that FPF had half-lives of 4.5–7.9 d and 10.0–16.9 d in ginseng plants and soil, respectively. The concentrations of total terminal residues in soil, ginseng plants, dried ginseng, and ginseng were less than 0.516, 2.623, 2.363, and 0.641 mg/kg, respectively. Based on these results, the soil environmental risk assessment shows that the environmental risk of FPF to soil organisms is acceptable. The processing factors for FPF residues in ginseng were 3.82–4.59, indicating that the concentration of residues increased in ginseng after drying. A dietary risk assessment showed that the risk of FPF residues from long-term and short-term dietary exposures to global consumers were 0.1–0.4% and 12.07–13.16%, respectively, indicating that the application of FPF to ginseng at the recommended dose does not pose a significant risk to consumers

A Multi-Residue Method for the Determination of 77 Pesticides in Red Ginseng Using QuEChERS and Gas Chromatography/Tandem Mass Spectrometry (GC-MS/MS)

A simple, sensitive, and rapid multi-residue analytical method was developed based on gas chromatography-tandem mass spectrometry (GC–MS/MS) and used to determine 77 multiclass pesticides in red ginseng. Samples were extracted and purified via a modified QuEChERS method. The calibration curves were in the range of 5 to 200 ng mL−1. The limits of detection (LODs) of the method were from 0.08 to 4.0 μg kg−1 and limits of quantification (LOQs) were in the range of 0.2–12.0 μg kg−1. The average recoveries of the method ranged from 61% to 133.9% at two spiked levels of 20 and 100 μg kg−1 in red ginseng samples, with relative standard deviations (RSDs) of 0.2% to 14.9%