73 research outputs found

    The Maize NBS-LRR Gene ZmNBS25 Enhances Disease Resistance in Rice and Arabidopsis

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    Nucleotide-binding site-leucine-rich repeat (NBS-LRR) domain proteins are immune sensors and play critical roles in plant disease resistance. In this study, we cloned and characterized a novel NBS-LRR gene ZmNBS25 in maize. We found that ZmNBS25 could response to pathogen inoculation and salicylic acid (SA) treatment in maize, and transient overexpression of ZmNBS25 induced a hypersensitive response in tobacco. High-performance liquid chromatography (HPLC) analysis showed that, compared to control plants, ZmNBS25 overexpression (ZmNBS25-OE) in Arabidopsis and rice resulted in higher SA levels. By triggering the expression of certain defense-responsive genes, ZmNBS25-OE enhanced the resistance of Arabidopsis and rice to Pseudomonas syringae pv. tomato DC3000 and sheath blight disease, respectively. Moreover, we found little change of grain size and 1000-grain weight between ZmNBS25-OE rice lines and controls. Together, our results suggest that ZmNBS25 can function as a disease resistance gene across different species, being a valuable candidate for engineering resistance in breeding programs

    An integrated tool for performance based engineering of structures in fire

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    Performance based engineering (PBE) is increasingly recognised as the gold standard for ensuring structural safety under extreme loading conditions such as a post-flashover fire. While no universally agreed methodology exists for implementing PBE for various kinds of extreme loadings in general, there are three clearly defined stages for doing so in order to design or assess structural resistance under fire loading. The fire loading is characterised in the first stage, which may range from simple prescribed time-temperature relationships if standard fires are adopted, which is against the spirit of PBE, to an expensive computational fluid dynamics simulation, which in most cases would constitute overkill. A number of options are available and gradually being developed that lie between these two extremes. A realistic characterisation of the load should in general allow the possibility of non-uniform heat fluxes to structural surfaces, which makes the second stage of determining structural temperatures very tedious. Furthermore, the computational models used in the third stage of determining nonlinear structural response are usually very different from the models used in the second stage thereby requiring significant manual intervention by the analyst. In the author’s view this, bar the need for further research on realistic fire scenarios, is the greatest obstacle in carrying out PBE for structural fire resistance design. This paper presents a simulation tool developed within the open source software framework OpenSees with the aim of integrating all the stages of the analysis discussed earlier in order to make PBE feasible even for design offices with modest resources in terms of trained analysts and computing hardware

    Wireless Monitoring of Small Strains in Intelligent Robots via a Joule Heating Effect in Stretchable Graphene–Polymer Nanocomposites

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    Flexible strain sensors are an important component for future intelligent robotics. However, the majority of current strain sensors must be electrically connected to a corresponding monitoring system via conducting wires, which increases system complexity and restricts the working environment for monitoring strains. Here, stretchable graphene–polymer nanocomposites that act as strain sensors using a Joule heating effect are reported. When the resistance of the sensor changes in response to a strain, the resulting change in temperature is wirelessly detected in an intelligent robot. By engineering and optimizing the surface structure of graphene–polymer nanocomposites, the fabricated strain sensors exhibit excellent stability when subjected to periodic temperature signals over 400 cycles while being periodically strained and deliver a high strain sensitivity of 7.03 × 10−4 °C−1 %−1 for strain levels of 0% to 30%. As a wearable electronic device, the approach provides the capability to wirelessly monitor small strains for intelligent robots at a high strain resolution of ≈0.1%. Moreover, when the strain sensing system operates as a multichannel structure, it allows precise strain detection simultaneously, or in sequence, for each finger of an intelligent robot.</p

    A coupled photo-piezo-catalytic effect in a BST-PDMS porous foam for enhanced dye wastewater degradation

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    Over the last decade, ferro-/piezo-electric materials have provided new directions to improve catalysis. However, current challenges that must be solved include secondary pollution by the piezoelectric particulates and a limited potential for reuse and recyclability. Here, we report an efficient approach of using a piezoceramic-polymer porous foam to package barium strontium titanate (BST) particulates and prevent secondary pollution, while being able to maintain a high photo-piezo-catalytic performance after 10 cycles of repeated catalytic reactions. The photo-piezo-catalysis achieves a 97.8% dye degradation and an enhanced performance of 275% when compared to individual photocatalysis by light irradiation or periodic low-frequency mechanical squeezing alone. It is suggested the photo-piezo-catalytic coupling effect combines the advantages of increased generated electron-hole pairs and the induced piezoelectric electric field leads to a higher degree of electron-hole separation. The BST-PDMS porous foam for photo-piezo-catalysis offers a potential approach in wastewater degradation via utilizing both solar energy and environmental mechanical sources.</p

    A novel lid-covering peptide inhibitor of nicotinic acetylcholine receptors derived from αd-conotoxin GeXXA

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    Nicotinic acetylcholine receptors (nAChRs) play a fundamental role in nervous signal transmission, therefore various antagonists and agonists are highly desired to explore the structure and function of nAChRs. Recently, a novel dimeric αD-conotoxin GeXXA was identified to inhibit nAChRs by binding at the top surface of the receptors, and the monomeric C-terminal domain (CTD) of αD-GeXXA retains some inhibitory activity. In this study, the internal dimeric N-terminal domain (NTD) of this conopeptide was further investigated. We first developed a regio-selective protection strategy to chemically prepare the anti-parallel dimeric NTD, and found that the isolated NTD part of GeXXA possesses the nAChR-inhibitory activity, the subtype-dependence of which implies a preferred binding of NTD to the β subunits of nAChR. Deletion of the NTD N-terminal residues did not affect the activity of NTD, indicating that the N-terminus is not involved in the interaction with nAChRs. By optimizing the sequence of NTD, we obtained a fully active single-chain cyclic NTD, based on which 4 Arg residues were found to interact with nAChRs. These results demonstrate that the NTD part of αD-GeXXA is a lid-covering nAChR inhibitor, displaying a novel inhibitory mechanism distinct from other allosteric ligands of nAChRs

    Temporal-spatial variation and regulatory mechanism of carbon budgets in territorial space through the lens of carbon balance: A case of the middle reaches of the Yangtze River urban agglomerations, China

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    As China’s largest cross-regional urban agglomerations, the middle reaches of the Yangtze River urban agglomerations (MRYRUA) possess both significant societal carbon source volume and ecological carbon sequestration capacity. Nevertheless, with the uncontrolled expansion of urban energy consumption activities and the industry migration from eastern coastal regions to inland cities, the carbon budget pattern of territorial space is increasingly unbalanced in the MRYRUA. To achieve low-carbon regulation, this study utilized land use and energy consumption data from 31 cities within the MRYRUA to establish a “carbon source-carbon sink” quantification and spatiotemporal exploration model, revealing the spatial-temporal variation of carbon budgets from 2005 to 2020. Furthermore, we developed a carbon balance indicator analysis system by employing the carbon offset rate (COR), carbon productivity (CP), Gini coefficient, ecological support coefficient (ESC), economic contribution coefficient (ECC), and functional zoning was performed. Finally, using the GM (1,1) model, we derived the carbon budget pattern for 2050 and explored the differentiated regulatory mechanisms under the carbon balance perspective. The results indicated that: (1) The MRYRUA’s territorial carbon budgets have increased annually, displaying a spatial distribution pattern with the highest values in the central region, followed by the northwest, and the lowest in the southeast near water bodies. The spatiotemporal differentiation effects manifest as an east–west axial development trend, with spatiotemporal clustering effects demonstrating a propensity for outward dispersion from the northern hot spot radiation core. (2) The MRYRUA’s COR has consistently remained below 10% and decreased annually, while the CP has shown a yearly increase at an accelerating rate. The ESC and ECC exhibit evident spatial heterogeneity among cities. In response to the carbon emission economic benefits and carbon sequestration ecological carrying capacity reflected by carbon balance indicators, each city was classified into low-carbon economic zones, carbon intensity control zones, carbon sink functional zones, and high-carbon optimization zones. (3) From 2020 to 2050, the polarization trend of the carbon budget pattern continues to intensify. Subsequently, we have established a differentiated territorial spatial carbon balance regulatory mechanism. This mechanism strengthens the leading role of low-carbon economic zones in the green low-carbon transition, moderately retains the carbon sink functional zones in the southeast with solid carbon fixation capabilities, and promotes the transition of the northern carbon intensity control zones and high-carbon optimization zones to low-carbon economic zones. The research findings provide a scientific basis for formulating territorial spatial planning policies from a carbon neutrality perspective
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