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Background Salinity is a worldwide factor limiting the agricultural production. Cotton is an important cash crop; however, its yield and product quality are negatively affected by soil salinity. Use of nanomaterials such as cerium oxide nanoparticles (nanoceria) to improve plant tolerance to stress conditions, e.g. salinity, is an emerged approach in agricultural production. Nevertheless, to date, our knowledge about the role of nanoceria in cotton salt response and the behind mechanisms is still rare. Results We found that PNC (poly acrylic acid coated nanoceria) helped to improve cotton tolerance to salinity, showing better phenotypic performance, higher chlorophyll content (up to 68% increase) and biomass (up to 38% increase), and better photosynthetic performance such as carbon assimilation rate (up to 144% increase) in PNC treated cotton plants than the NNP (non-nanoparticle control) group. Under salinity stress, in consistent to the results of the enhanced activities of antioxidant enzymes, PNC treated cotton plants showed significant lower MDA (malondialdehyde, up to 44% decrease) content and reactive oxygen species (ROS) level such as hydrogen peroxide (H 2 O 2 , up to 79% decrease) than the NNP control group, both in the first and second true leaves. Further experiments showed that under salinity stress, PNC treated cotton plants had significant higher cytosolic K + (up to 84% increase) and lower cytosolic Na + (up to 77% decrease) fluorescent intensity in both the first and second true leaves than the NNP control group. This is further confirmed by the leaf ion content analysis, showed that PNC treated cotton plants maintained significant higher leaf K + (up to 84% increase) and lower leaf Na + content (up to 63% decrease), and thus the higher K + /Na + ratio than the NNP control plants under salinity stress. Whereas no significant increase of mesophyll cell vacuolar Na + intensity was observed in PNC treated plants than the NNP control under salinity stress, suggesting that the enhanced leaf K + retention and leaf Na + exclusion, but not leaf vacuolar Na + sequestration are the main mechanisms behind PNC improved cotton salt tolerance. qPCR results showed that under salinity stress, the modulation of HKT1 but not SOS1 refers more to the PNC improved cotton leaf Na + exclusion than the NNP control. Conclusions PNC enhanced leaf K + retention and Na + exclusion, but not vacuolar Na + sequestration to enable better maintained cytosolic K + /Na + homeostasis and thus to improve cotton salt tolerance. Our results add more knowledge for better understanding the complexity of plant-nanoceria interaction in terms of nano-enabled plant stress tolerance. Graphic abstract

In order to improve the motion recognition effect of sports athletes based on image recognition technology, this study takes the current common diving athletes as the research material in the actual research, and combines the research status of image recognition to study the athlete’s motion recognition from image processing. Simultaneously, in this study, the gradient segmentation method is used to segment the image, the research object is segmented from the video image, the traditional image grayscale method is improved, and the image segmentation algorithm adapted to the diving motion is obtained. On this basis, this study combines Gaussian mixture background modeling and background subtraction to achieve the detection and extraction of target human body regions, and uses morphological operators to deal with noise and void phenomena in foreground images. The example analysis shows that the proposed method has certain practicality and can provide theoretical reference for subsequent related research.

Bacterial diseases are one of the most common issues that result in crop loss worldwide, and the increasing usage of chemical pesticides has caused the occurrence of resistance in pathogenic bacteria and environmental pollution problems. Nanomaterial mediated gene silencing is starting to display powerful efficiency and environmental friendliness for improving plant disease resistance. However, the internalization of nanomaterials and the physiological mechanisms behind nano-improved plant disease resistance are still rarely understood. We engineered the polyethyleneimine (PEI) functionalized gold nanoparticles (PEI-AuNPs) with fluorescent properties and ROS scavenging activity to act as siRNA delivery platforms. Besides the loading, protection, and delivery of nucleic acid molecules in plant mature leaf cells by PEI-AuNPs, its fluorescent property further enables the traceability of the distribution of the loaded nucleic acid molecules in cells. Additionally, the PEI-AuNPs-based RNAi delivery system successfully mediated the silencing of defense-regulated gene AtWRKY1 . Compared to control plants, the silenced plants performed better resistance to Pseudomonas syringae , showing a reduced bacterial number, decreased ROS content, increased antioxidant enzyme activities, and improved chlorophyll fluorescence performance. Our results showed the advantages of AuNP-based RNAi technology in improving plant disease resistance, as well as the potential of plant nanobiotechnology to protect agricultural production. Highlights Polyethyleneimine functionalized gold nanoparticles (PEI-AuNPs) with fluorescent properties and reactive oxygen species (ROS) scavenging ability are synthesized rationally; PEI-AuNPs with fluorescent properties act as the indicator to evaluate the nuclear acid internalization efficiency; PEI-AuNPs platform successfully mediate AtWRKY1 gene silencing and Pst DC3000 resistance by scavenging ROS, increasing antioxidant enzyme activity, and improving photosynthesis.

Water‐related ecosystem services (WES) provided by urban rivers are influenced by complex interactions between social and ecological systems. Understanding the public perception of WES is crucial for sustainable planning and management of urban rivers in the future. Although studies on public perception on WES have been growing in recent years, relevant research on urban rivers, particularly on how biophysical factors influence WES perception, remains limited. This study examines the public perception of WES across three types of urban rivers in Jinan, China, using a combination of questionnaire surveys and field investigations. Binary logistic regression is applied to analyse how the biophysical characteristics of urban rivers affect the public perception of WES. The main findings are as follows: (1) Public awareness of WES provided by urban rivers is generally low, especially regarding water purification. (2) The type of river significantly influences public perception, with natural rivers eliciting higher perceptions of WES. (3) The key factors that affect public perceptions of WES include water quality, flow speed, sinuosity, arbour coverage and habitat diversity. (4) Synergistic positive effects on public perceptions are observed among water quality, sinuosity and habitat diversity. This research supports the promotion of public engagement in environmental management and provides valuable insights for policy development and the sustainable development of urban rivers. Read the free Plain Language Summary for this article on the Journal blog. 摘要 城市河流所提供的与水相关的生态系统服务(WES)受社会系统与生态系统间复杂交互作用的影响。理解公众对WES的感知对于未来城市河流的可持续规划与管理至关重要。尽管近年来关于公众对WES感知的研究日益增多，但针对城市河流的相关研究，特别是生物物理因素如何影响WES认知的探讨仍显不足。 本研究通过问卷调查与实地考察相结合的方法，考察了中国济南市三类城市河流WES的公众感知，并采用二元逻辑回归分析城市河流生物物理特征如何影响了公众感知。 主要发现如下:(1) 公众对城市河流WES的感知普遍较低，尤其在水质净化方面；(2) 河流类型显著影响了公众感知，公众对自然河流的感知更高；(3) 影响公众感知的关键因素包括水质、流速、河道弯曲度、树木覆盖率及栖息地多样性。(4) 水质、河道弯曲度与生境多样性对公众感知呈现协同正向效应。 本研究支持并推动了公众参与环境治理，为政策制定及城市河流可持续发展提供了重要启示。 Read the free Plain Language Summary for this article on the Journal blog.

Lateral root (LR) formation is important for plant growth. ROS (reactive oxygen species)play an important role in LR formation. While how nanomaterials affect ROS distribution to promote LR formation and the role of ROS in primordia in LR formation are rarely known. Cerium oxide nanoparticles (nanoceria), as a potent ROS scavenger, are widely used in plants. This study investigates the effects of poly (acrylic acid) nanoceria (PNC, 6.5 nm, −36 mV), aminated nanoceria (ANC, 6.9 nm, 30 mV), and bulk nanoceria (BNC, 84.9 nm, −5.5 mV) on LR formation in Arabidopsis. Only PNC increased LR numbers by 73.5%, reducing root H2O2 levels by up to 90.44% and altering O₂•− distribution in LR primordia (LRP). Furthermore, DPI (diphenyleneiodonium, O₂•− inhibitor) decreased LR numbers by 18.9%, while PNC treatment reversed this inhibition (12.25 ± 0.53 vs 8.38 ± 0.52). Transcriptome analysis shows PNC regulated ROS metabolism via genes like peroxiredoxins and peroxidases, promoting LR formation. Interestingly, PNC does not affect auxin distribution (confirmed by DR5pro::GFP lines) or alleviate NPA‐induced (N‐1‐naphthylphthalamic acid, an auxin transport inhibitor) LR inhibition. These findings suggest that PNC enhances LR formation through ROS modulation rather than auxin signaling. PNC promote lateral root formation throughmodulating the dirstribution of superoxide anion rather than auxin.

MicroRNAs are endogenous short chain nucleotide RNAs that regulate gene function by direct binding of target mRNAs. In this study, we investigated the effects of microRNA-206 (miR-206) on the development of gastric cancer. miR-206 was first confirmed to be downregulated in gastric cancer specimens. Conversely, upregulation of c-Met was confirmed in tissue samples of human gastric cancer, with its level inversely correlated with miR-206 expression. Introduction of miR-206 inhibited cellular proliferation by inducing G1 cell cycle arrest, as well as migration and invasion. Moreover, important proliferation and/or migration related molecules such as c-Met, CDK4, p-Rb, p-Akt and p-ERK were confirmed to be downregulated by Western blot analysis. Targeting of c-Met also directly affected AGS cell proliferation, migration and invasion. In vivo, miR-206 expressing tumor cells also displayed growth delay in comparison to unaffected tumor cells. Our results demonstrated that miR-206 suppressed c-Met expression in gastric cancer and could function as a potent tumor suppressor in c-Met overexpressing tumors. Inhibition of miR-206 function could contribute to aberrant cell proliferation and migration, leading to gastric cancer development.

Al-Cu-Mn alloys are used in components in automotive and aircraft industry which work at high temperature. Recent research is focused on Al-Cu-Mn alloys to enhance their performance by promoting the formation of thermally stable phase particles. In this study, the effect of Cu/Mn content on microstructure and mechanical properties of two Al-Cu-Mn alloys (Cu/Mn wt.% ratio = 5.56, 2.75) is investigated by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and tensile testing. Results reveal that as-cast microstructure of both the alloys consists of trunks of α-Al dendrites surrounded by Cu-rich interdendritic region. After solution treatment, a great amount of Al-Cu-Mn intermetallic compound particles are found to precipitate adjacent to this region. Alloy with low Cu/Mn content ratio exhibits high strength due to relatively high amount of Al-Cu-Mn (T-phase) particles.

Salinity is an issue impairing crop production across the globe. Under salinity stress, besides the osmotic stress and Na+ toxicity, ROS (reactive oxygen species) overaccumulation is a secondary stress which further impairs plant performance. Chloroplasts, mitochondria, the apoplast, and peroxisomes are the main ROS generation sites in salt-stressed plants. In this review, we summarize ROS generation, enzymatic and non-enzymatic antioxidant systems in salt-stressed plants, and the potential for plant biotechnology to maintain ROS homeostasis. Overall, this review summarizes the current understanding of ROS homeostasis of salt-stressed plants and highlights potential applications of plant nanobiotechnology to enhance plant tolerance to stresses.

Pt bimetallic catalysts have been studied and used in the industry to prevent catalyst poisoning via coke formation and sintering in dehydrogenation of light alkanes. However, reactions at a molecular level have not been thoroughly studied due to difficulties in controlling conditions such as catalyst size, composition, distribution, surface area and substrate porosity, etc. Using surface techniques such as x-ray photoelectron spectroscopy (XPS), low energy ion scattering spectroscopy (ISS), and temperature programmed desorption (TPD), analysis of bimetallic modified size-selected Pt clusters via atomic layer deposition (ALD) methods under ultra-high vacuum (UHV) conditions can effectively correlate the catalyst catalytic properties and reaction mechanisms to cluster size, composition, geometric and electronic structures.With Pt clusters acting as nucleation sites, ALD process using SnCl4 and H2 gases created Pt7Sn3 clusters on alumina substrate. Sn deposition greatly changed the number and type of Pt-ethylene binding sites that prevented the formation of coke precursors. The Pt7Sn3 clusters were also found to be highly resistant to thermal sintering after being repeatedly heated to high temperatures.Ge was believed to be an effective promoter in coke and sintering prevention of Pt clusters for light alkane dehydrogenation; using a GeCl4 based ALD-like technique, Pt4Ge clusters were successfully developed on alumina substrates that were highly stable catalysts that prevented catalyst deactivation in a different mechanism than the previously developed PtSn clusters. The Pt4Ge clusters did not suppress coke formation completely; instead, it produced small amounts of carbon that was a self-limiting process and did not cause catalyst deactivation. Eventually, Pt4GeC2 clusters were formed that remained active and selective against coking.Finally, Ptn (n = 4,7,11) on alumina substrate were modified with Ge, and it was found that each cluster size had a slightly different preference of selective Ge binding that formed Pt4Ge, Pt7Ge2 and Pt11Ge4 clusters. All of the clusters were effective in coke and sintering prevention. Temperature-dependent ISS indicated the C2D4 that were responsible for dehydrogenation occupied the top of the Pt atoms for both Pt and PtGe clusters. Further DFT and more sensitive surface studies are required to investigate the geometric and electronic structures of different PtGe cluster sizes and their effects on ethylene and CO binding due to Pt clusters with more Pt exposure did not correspond to more molecule binding sites.