In many parts of the world, apple trees suffer from severe foliar damage each year due to infection of Alternaria blotch (Alternaria alternata f. sp. Mali), resulting in serious economic losses to ...growers. Traditional methods for disease detection and severity classification mostly rely on manual labor, which is slow, labor-intensive and highly subjective. There is an urgent need to develop an effective protocol to rapidly and accurately evaluate disease severity. In this study, DeeplabV3+, PSPNet and UNet were used to assess the severity of apple Alternaria leaf blotch. For identifications of leaves and disease areas, the dataset with a total of 5382 samples was randomly split into 74% (4004 samples) for model training, 9% (494 samples) for validation, 8% (444 samples) for testing and 8% (440 samples) for overall testing. Apple leaves were first segmented from complex backgrounds using the deep-learning algorithms with different backbones. Then, the recognition of disease areas was performed on the segmented leaves. The results showed that the PSPNet model with MobileNetV2 backbone exhibited the highest performance in leaf segmentation, with precision, recall and MIoU values of 99.15%, 99.26% and 98.42%, respectively. The UNet model with VGG backbone performed the best in disease-area prediction, with a precision of 95.84%, a recall of 95.54% and a MIoU value of 92.05%. The ratio of disease area to leaf area was calculated to assess the disease severity. The results showed that the average accuracy for severity classification was 96.41%. Moreover, both the correlation coefficient and the consistency correlation coefficient were 0.992, indicating a high agreement between the reference values and the value that the research predicted. This study proves the feasibility of rapid estimation of the severity of apple Alternaria leaf blotch, which will provide technical support for precise application of pesticides.
Benzoylaconitine (BAC), the main hydrolysate of aconitine, is a lower toxic monoester type alkaloid considered as the pharmacodynamic constituent in Aconitum species. In this study, the effects and ...mechanisms of BAC on production of inflammatory cytokines interleukin (IL)-6 and IL-8 were investigated in IL-1β-stimulated human synovial SW982 cells. The SW982 cells were incubated with BAC (0, 5 and 10 µM) before stimulating with IL-1β (10 ng/mL). The results revealed that BAC suppressed gene and protein expression of IL-6 and IL-8 induced by IL-1β. BAC decreased activation of mitogen-activated protein kinase (MAPK) and phosphorylation of Akt. BAC also inhibited degradation of inhibitor of kappaB (IκB)-α, phosphorylation and nuclear transposition of p65 protein. The results demonstrate that BAC exerts an anti-inflammatory effect dependent on MAPK, Akt and nuclear factor-κB (NF-κB) pathways in human synovial cells stimulated with IL-1β, suggesting that BAC may be exploited as a potential therapeutic agent for rheumatoid arthritis (RA) treatment.
The main theme of this paper is to propose a switching method to reduce the loss of phase-shift-controlled full-bridge converter under light-load and standby conditions. It will be shown that the ...efficiency can be improved using the proposed switching control technique. The presented switching control technique controls the full-bridge converter by pulsewidth-modulated (PWM) switching mode under light-load condition and PWM switching with burst mode under standby condition. The transition point between phase-shift switching method and the proposed method is investigated and confirmed by experimental results. A field-programmable-gate-array-based digital-controlled experimental system has been set up. The specifications of the converter include: input voltage = 400 V, output voltage = 12 V, and output power = 400 W. Experimental results show that the efficiency improvement can be up to 26% under light-load condition and the standby power is less than 1 W. These results confirm the effectiveness of the proposed switching control technique.
The construction of the SCF3‐containing 1,1‐diaryl tertiary carbon stereocenters with high enantioselectivities is reported via a nickel‐catalyzed asymmetric C−C coupling strategy. This method ...demonstrates simple operations, mild conditions and excellent functional group tolerance, with newly designed SCF3‐containing synthon, which can be easily obtained from commercially available benzyl bromide and trifluoromethylthio anion in a two‐step manner. Further substrate exploration indicated that the reaction system could be extended to diverse perfluoroalkyl sulfide (SC2F5, SC3F7, SC4F9, SCF2CO2Et)‐substituted 1,1‐diaryl compounds with excellent enantioselectivities. The synthetic utility of this transformation was further demonstrated by convenient derivatization to optical SCF3‐containing analogues of bioactive compounds without an apparent decrease in enantioselectivity.
The construction of chiral SRf (SCF3, SC2F5, SC3F7, SC4F9 and SCF2CO2Et)‐containing 1,1‐diaryl tertiary carbon centers with high enantioselectivities was developed by a nickel catalyzed asymmetric Negishi coupling reaction. The synthetic utility of this strategy was demonstrated in a gram scale reaction and the syntheses of optical analogues of bioactive compounds by introducing SCF3 groups without an apparent decrease in enantioselectivity.
To date, photothermal sensitizers include organic and inorganic nanomaterials for biomedical applications. However, the impediments of low biodegradability and potential toxicity hinder their further ...applications in clinics. Liquid metal nanospheres show superior photothermal effects under near-infrared laser irradiation, in addition, a transformation in shape can be triggered, which also promotes biodegradability that helps to avoid potential systemic toxicity. Here, we fabricated tunable liquid metal nanoparticles having sphere-shaped to rod-shaped characteristics, resulting in good biocompatibility, favorable photothermal conversion efficiency, and targeting capability to tumors. The synthesis strategy is easy to achieve through one-step sonication. We systematically evaluated the photothermal properties of these liquid metal nanoparticles as well as their destructive effects on tumors in a quantitative way both in vitro and in vivo under laser exposure. Results have shown for the first time in mice that gallium nanorods, regulated and controlled through the production of GaO(OH), displayed outstanding photothermal conversion efficiency and exhibited distinct temperature elevation compared to gallium nanospheres and gallium-indium alloy nanorods. These shape transformable and biocompatible gallium nanorods establish the basis for the future laser ablation of tumors to achieve enhanced therapeutic outcomes. This shape tunability of a smart nano-liquid metal directly contributes to enhanced photothermal therapy in mice and opens new opportunities for potential applications with tumor therapy and imaging.
Background/Aims: This study was developed to investigate a potential therapeutic method for myocardial ischemia/reperfusion injury involving the promotion of miR-24-3p expression. Methods: Microarray ...analysis was used to screen differentially expressed genes in a myocardial ischemia/reperfusion (I/R) injury mouse model. Gene set enrichment analysis was utilized to determine vital signaling pathways. Targeting verification was conducted with a luciferase reporter assay. Myocardial I/R injury was developed in mice, and the expression levels of RIPK1 and miR-24-3p were investigated by qRT-PCR and Western blot. Hemodynamic parameters and the activity of serum myocardial enzymes were measured to evaluate cardiac function. Infarct area was observed through HE and TTC staining. Myocardial cell apoptosis was examined by TUNEL staining and caspase-3 activity analysis. Results: RIPK1 was an upregulated mRNA found by microarray analysis and a verified target of the downregulated miRNA miR-24-3p. The upregulation of RIPK1 (1.8-fold) and the downregulation of miR-24-3p (0.3-fold) were confirmed in I/R mice. RIPK1 led to impaired cardiac function indexes, increased infarct area and cell apoptosis, while miR-24-3p could reverse the injury by regulating RIPK1. The TNF signaling pathway was proven to be involved in myocardial I/R injury through the detection of the dysregulation of related proteins. Conclusion: In conclusion, RIPK1 was upregulated and miR-24-3p was downregulated in a myocardial I/R injury mouse model. RIPK1 could aggravate myocardial I/R injury via the TNF signaling pathway, while miR-24-3p could suppress RIPK1 and therefore exert cardioprotective effects in myocardial I/R injury.
The organic–inorganic hybrid perovskite solar cells present a rapid improvement on power conversion efficiency from 3.8% to 25.5% in the past decades. Owing to the tuneable bandgaps, low‐cost, and ...ease of fabrication, perovskites become ideal candidate materials for fabricating tandem solar cells, especially for efficient and high‐voltage monolithic two‐terminal devices. In this review, an overview of recent advances in various monolithic perovskite‐based tandem solar cells with a focus on the key challenges is provided. Subsequently, the recombination layer materials, construction of wide‐bandgap perovskite layer, stability of narrow‐bandgap, and current matching principle in tandems are highlighted in order to optimize the output voltage and conversion efficiency of tandem solar cells. Finally, the recent progress is summarized with a focus on potential applications of tandem solar cells for energy conversion and storage, including hydrogen production by water splitting, CO2 reduction, supercapacitors, and rechargeable batteries, benefiting from the adjustable output voltage of tandem solar cells. It is hoped that this work can offer a feasible strategy to explore more possibilities for fabricating new two‐terminal tandem solar cells with high voltage and high conversion efficiency for energy conversion and storage.
This review provides an essential feature of two‐terminal monolithic perovskite tandem solar cells, and an outlook about on the achieved and potential applications of perovskite‐based tandem devices for energy conversion and storage. These include hydrogen production by water splitting, CO2 reduction, supercapacitors, and rechargeable batteries, benefiting from the adjustable output voltage of tandem solar cells.
Emerging cybersecurity vulnerabilities in supervisory control and data acquisition (SCADA) systems are becoming urgent engineering issues for modern substations. This paper proposes a novel intrusion ...detection system (IDS) tailored for cybersecurity of IEC 61850 based substations. The proposed IDS integrates physical knowledge, protocol specifications, and logical behaviors to provide a comprehensive and effective solution that is able to mitigate various cyberattacks. The proposed approach comprises access control detection, protocol whitelisting, model-based detection, and multiparameter-based detection. This SCADA-specific IDS is implemented and validated using a comprehensive and realistic cyber-physical test-bed and data from a real 500 kV smart substation.
Tungsten inert gas (TIG) welding with flat tungsten electrode can effectively reduce the arc pressure distribution, restrain welding defects, and improve the welding speed of thin plate. In this ...article, the arc characteristics of symmetric and asymmetric flat tungsten electrodes are studied by selecting different tip angles and tilt angles of flat tungsten electrodes. The temperature variation, current density variation, flow field variation, and pressure variation of flat tungsten electrode arc are calculated. Based on the approximate formula of cathode jet intensity of flat tungsten arc, the variation laws of various physical fields are clarified from the perspective of flow.
Horizontally stacked Ge-nanosheet gate-all-around FETs (GAAFETs) are demonstrated for the first time. The Ge/Si multilayers instead of the typically used Ge/SiGe ones were epitaxially grown as the ...starting material. To avoid island growth, the Ge/Si multilayers were epitaxially grown at a low temperature. Using megasonic agitation, the Si in Ge/Si multilayers can be easily etched with good selectivity using a tetramethylammonium hydroxide water solution at an appropriate temperature. Finally, the p- and n-GAAFETs of gate length (<inline-formula> <tex-math notation="LaTeX">{L}_{G}) </tex-math></inline-formula> 90 nm were fabricated, and drive currents <inline-formula> <tex-math notation="LaTeX">{I}_{ \mathrm{\scriptscriptstyle ON}} </tex-math></inline-formula> of 1650 and <inline-formula> <tex-math notation="LaTeX">1510~\mu \text{A}/\mu \text{m} </tex-math></inline-formula> (per width of channel footprint) were achieved, respectively.
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