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Biological nitrogen and carbon fixation:Bridging the gap between synthetic symbioses and synthetic biology 被引量:1
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作者 Qi Cheng Chukang Ma Xuelu Wang 《The Crop Journal》 2026年第1期74-86,共13页
Biological nitrogen fixation(BNF)and photosynthetic carbon fixation underpin food production and climate mitigation,yet natural systems are constrained by oxygen sensitivity,high energy demand,and inefficient catalyst... Biological nitrogen fixation(BNF)and photosynthetic carbon fixation underpin food production and climate mitigation,yet natural systems are constrained by oxygen sensitivity,high energy demand,and inefficient catalysts.This review synthesizes advances that recast these processes as engineering targets and proposes a conceptual roadmap that bridges synthetic symbioses with the synthetic biology of enzymes and pathways.For BNF,progress spans cross-kingdom strategies—from refactoring nif gene sets and targeting nitrogenase assembly to eukaryotic organelles,to engineering plant-associated diazotrophs,rhizosphere control circuits,and emerging nodule-like microenvironments.For carbon assimilation,new-to-nature CO_(2)-fixation modules and photorespiratory bypasses illustrate how pathway redesign and alternative carboxylases can circumvent key Calvin–Benson–Bassham limitations,and expanding photosynthetic light capture offers additional leverage.Across these domains,we extract common design principles:(i)nitrogenase output is increasingly governed by carbon/energy supply and electron delivery as much as by oxygen protection;(ii)robust function requires compartment-aware enzyme–chassis coordination,substrate channeling,and dynamic regulation using sensors and control circuits;and(iii)scalable implementation may benefit from distributing metabolic labor across engineered consortia rather than forcing all functions into a single host.We discuss enabling technologies—including AI-guided protein design and directed evolution,cell-free prototyping,chassis toolkits,and materials/bioelectrochemical interfaces—that can accelerate design–build–test–learn cycles and reduce barriers to deployment.Together,these insights define a path toward integrated nitrogen and carbon fixation systems for low-emission agriculture and biomanufacturing. 展开更多
关键词 Biological nitrogen fixation Photosynthetic carbon fixation nitrogenase engineering Non-natural enzymes AI-guided protein design
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Dissolved organic matter characteristics linked to bacterial community succession and nitrogen removal performance in woodchip bioreactors
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作者 Achen Wang Xiang Li +5 位作者 Xuesong Luo Guangwen He Daqing Huang Qiaoyun Huang Xue-Xian Zhang Wenli Chen 《Journal of Environmental Sciences》 2025年第2期625-636,共12页
Woodchip bioreactors are an eco-friendly technology for removing nitrogen(N)pollution.However,there needs to be more clarity regarding the dissolved organicmatter(DOM)characteristics and bacterial community succession... Woodchip bioreactors are an eco-friendly technology for removing nitrogen(N)pollution.However,there needs to be more clarity regarding the dissolved organicmatter(DOM)characteristics and bacterial community succession mechanisms and their association with the N removal performance of bioreactors.The laboratory woodchip bioreactors were continuously operated for 360 days under three influent N level treatments,and the results showed that the average removal rate of TN was 45.80 g N/(m^(3)·day)when the influent N level was 100 mg N/L,which was better than 10 mg N/L and 50 mg N/L.Dynamic succession of bacterial communities in response to influent N levels and DOM characteristics was an important driver of TN removal rates.Medium to high N levels enriched a copiotroph bacterial module(Module 1)detected by network analysis,including Phenylobacterium,Xanthobacteraceae,Burkholderiaceae,Pseudomonas,and Magnetospirillaceae,carrying N-cycle related genes for denitrification and ammonia assimilation by the rapid consumption of DOM.Such a process can increase carbon limitation to stimulate local organic carbon decomposition to enrich oligotrophswith fewer N-cycle potentials(Module 2).Together,this study reveals that the compositional change ofDOMand bacterial community succession are closely related to N removal performance,providing an ecological basis for developing techniques for N-rich effluent treatment. 展开更多
关键词 Bacterial community succession Dissolved organic matter N removal performance Woodchip bioreactors
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NLRP3 inflammasome and gut microbiota–brain axis:A new perspective on white matter injury after intracerebral hemorrhage 被引量:1
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作者 Xiaoxi Cai Xinhong Cai +4 位作者 Quanhua Xie Xueqi Xiao Tong Li Tian Zhou Haitao Sun 《Neural Regeneration Research》 2026年第1期62-80,共19页
Intracerebral hemorrhage is the most dangerous subtype of stroke,characterized by high mortality and morbidity rates,and frequently leads to significant secondary white matter injury.In recent decades,studies have rev... Intracerebral hemorrhage is the most dangerous subtype of stroke,characterized by high mortality and morbidity rates,and frequently leads to significant secondary white matter injury.In recent decades,studies have revealed that gut microbiota can communicate bidirectionally with the brain through the gut microbiota–brain axis.This axis indicates that gut microbiota is closely related to the development and prognosis of intracerebral hemorrhage and its associated secondary white matter injury.The NACHT,LRR,and pyrin domain-containing protein 3(NLRP3)inflammasome plays a crucial role in this context.This review summarizes the dysbiosis of gut microbiota following intracerebral hemorrhage and explores the mechanisms by which this imbalance may promote the activation of the NLRP3 inflammasome.These mechanisms include metabolic pathways(involving short-chain fatty acids,lipopolysaccharides,lactic acid,bile acids,trimethylamine-N-oxide,and tryptophan),neural pathways(such as the vagus nerve and sympathetic nerve),and immune pathways(involving microglia and T cells).We then discuss the relationship between the activated NLRP3 inflammasome and secondary white matter injury after intracerebral hemorrhage.The activation of the NLRP3 inflammasome can exacerbate secondary white matter injury by disrupting the blood–brain barrier,inducing neuroinflammation,and interfering with nerve regeneration.Finally,we outline potential treatment strategies for intracerebral hemorrhage and its secondary white matter injury.Our review highlights the critical role of the gut microbiota–brain axis and the NLRP3 inflammasome in white matter injury following intracerebral hemorrhage,paving the way for exploring potential therapeutic approaches. 展开更多
关键词 gut microbiota gut microbiota–brain axis immune intracerebral hemorrhage NEUROINFLAMMATION NLRP3 protein stroke THERAPEUTICS white matter injury
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Post-anthesis dry matter production and leaf nitrogen distribution are associated with root-derived cytokinins gradient in rice
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作者 Kuanyu Zhu Yuemei Xu +9 位作者 Zhiwei Sun Yajun Zhang Weiyang Zhang Yunji Xu Junfei Gu Hao Zhang Zhiqin Wang Lijun Liu Jianhua Zhang Jianchang Yang 《Journal of Integrative Agriculture》 2025年第6期2106-2122,共17页
Aligning leaf nitrogen(N) distribution to match the light gradient is crucial for maximizing canopy dry matter production(DMP) and improving N utilization efficiency. However, the relationship between the gradient of ... Aligning leaf nitrogen(N) distribution to match the light gradient is crucial for maximizing canopy dry matter production(DMP) and improving N utilization efficiency. However, the relationship between the gradient of root-derived cytokinins and N distribution in rice leaves and its impact on DMP and the underlying mechanisms remains poorly understood. A two-year field experiment was conducted using two japonica N-efficient varieties(NEVs) and two japonica N-inefficient varieties(NIVs) under four different N rates(0, 90, 180, and 360 kg N ha^(-1)). These selected varieties exhibited similar values in the coefficient of light extinction(K_(L)). Results showed that at lower N rates(0–180 kg N ha^(-1)), the NEVs exhibited greater dry matter weight at maturity, higher grain yield, and improved internal N use efficiency(IE_(N)) compared to the NIVs, despite possessing comparable total N uptake. Compared with the NIVs, the NEVs exhibited a more pronounced nitrogen distribution gradient in leaves, as indicated by the coefficient of nitrogen extinction(K_(N)) values during the middle and early grain-filling stages. This enhanced gradient led to improved coordination between light and nitrogen, resulting in greater photosynthetic production, particularly at lower N rates. Furthermore, the NEVs demonstrated a larger gradient of zeatin(Z)+zeatin riboside(ZR) in leaves(i.e., higher ratios of Z+ZR levels between upper and lower leaves), enhanced expression levels of genes related to N export in lower leaves and Z+ZR loading in the root, respectively, elevated enzymes activities related to N assimilation in upper leaves, in relative to the NIVs. Correlation and random forest analyses demonstrated a strong positive correlation between the Z+ZR gradient, K_(N), and DMP, and the gradient facilitated the export of N from lower leaves and its assimilation in upper leaves, contributing significantly to both K_(N) and DMP. This process was closely linked to root activity, including root oxidation activity, root Z+ZR content, and Z+ZR loading capacity, as confirmed by applying an inhibitor or a promoter of cytokinins biosynthesis to roots. Interestingly, at the N rate of 360 kg N ha^(-1), both NEVs and NIVs showed indistinguishable plant traits, achieving a super high-yielding level(over 10.5 t ha^(-1)) but with remarkably low IE_(N). The results suggest that increasing the Z+ZR gradient can improve K_(N) and DMP, where it needs to maintain higher root activity, thus leading to high yield and high IE_(N). Further research is needed to explore and develop cultivation practices with reduced N to unlock the super-high-yielding potential of the NEVs. 展开更多
关键词 rice(Oryza sativa L.) grain yield dry matter production cytokinins gradient N distribution internal N use efficiency
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Exploring the optimal nitrogen threshold for global grassland restoration
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作者 Qi Zhang Fu Chen +12 位作者 Zhanbin Luo Jun Fan Yanfeng Zhu Jing Ma Yongjun Yang Xi-en Long Alejandro Gonzalez-Ollauri Miao Gan Weihong Guo Yuxiang Ma Qiaoling Wang Shenglu Zhou Mingan Shao 《Geography and Sustainability》 2026年第1期66-81,共16页
Amid accelerating global land degradation,establishing high-efficiency ecological restoration principles and frameworks is crucial.Here,we explore the application of threshold effects in the ecological restoration pro... Amid accelerating global land degradation,establishing high-efficiency ecological restoration principles and frameworks is crucial.Here,we explore the application of threshold effects in the ecological restoration process based on field experiments and globally available experimental data from 173 sites.Combining data integration analysis and meta-analysis,we collectively verified the universality of threshold effects in grasslands.The global grasslands’average nitrogen application threshold is 3.78 g·m^(-2)·yr^(−1),while the threshold value of degraded grassland(3.65 g·m^(-2)·yr^(−1))is lower than that of nondegraded grassland(5.90 g·m^(-2)·yr^(−1)).The low nitrogen-driven thresholds are affected by degradation status,climate(precipitation and temperature),and other site conditions,but not fertilization forms.Independent experiments further demonstrated that an increase in soil moisture content can lead to the disappearance of nitrogen threshold effects,revealing that ecological threshold effects are influenced by ecosystem stress factors.Following the significant increase in plant biomass triggered by the nitrogen threshold,the ecosystem undergoes systemic improvement.Soil organic carbon,urease activity,soil microbial diversity,and other soil properties are significantly enhanced.Soil nitrogen cycle-related microbial communities and soil physicochemical attributes are significantly activated.The results indicate that a threshold response pattern may develop before nitrogen saturation is reached,and low nitrogen input can boost productivity and improve the plant-soil-microbe system.Our findings reveal a nonprogressive path of restoration in degraded ecosystems,and thus,restoration based on threshold effects can offer an efficient and safe solution to combat ecological degradation. 展开更多
关键词 Ecological restoration Thresholds effect GRASSLAND nitrogen META-ANALYSIS
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Associations of indoor airborne microbiome with systemic inflammation in the context of indoor particulate matter pollution and the metabolic mechanisms
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作者 Yetong Zhao Luyi Li +8 位作者 Wenlou Zhang Shan Liu Wanzhou Wang Xuezhao Ji Di Yang Lifang Zhao Zhihong Zhang Xinbiao Guo Furong Deng 《Journal of Environmental Sciences》 2026年第1期187-198,共12页
Microorganisms constitute an essential component in the indoor environment,which is closely related to hu-man health.However,there is limited evidence regarding the associations between indoor airborne microbiome and ... Microorganisms constitute an essential component in the indoor environment,which is closely related to hu-man health.However,there is limited evidence regarding the associations between indoor airborne microbiome and systemic inflammation,as well as whether this association is modified by indoor particulate matter and the underlying mechanisms.In this prospective repeated-measure study among 66 participants,indoor airborne mi-crobiome was characterized using amplicon sequencing and qPCR.Indoor fine particulate matter(PM_(2.5))and inhalable particulate matter(PM10)were measured.Systemic inflammatory biomarkers were assessed,including white blood cell(WBC),neutrophil(NEUT),monocyte,eosinophil counts,and their proportions.Targeted serum amino acid metabolomics were conducted to explore the underlying mechanisms.Linear mixed-effect models re-vealed that bacterial and fungal Simpson diversity were significantly associated with decreased WBC and NEUT.For example,for each interquartile range increase in the bacterial Simpson diversity,WBC and NEUT changed by-4.53%(95%CI:-8.25%,-0.66%)and-5.95%(95%CI:-11.3%,-0.27%),respectively.Notably,increased inflammatory risks of airborne microbial exposure were observed when indoor PM_(2.5) and PM10 levels were below the WHO air quality guidelines.Mediation analyses indicated that dopamine metabolism partially mediated the anti-inflammatory effects of fungal diversity exposure.Overall,our study indicated protection from a diverse indoor microbial environment on cardiovascular health and proposed an underlying mechanism through amino acid metabolism.Additionally,health risks associated with microbial exposure deserve more attention in con-texts of low indoor particulate matter pollution.Further research is necessary to fully disentangle the complex relationships between indoor microbiome,air pollutants,and human health. 展开更多
关键词 Indoor air BIOAEROSOLS MICROBIOME Particulate matter Systemic inflammation Amino acid metabolism
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Community assembly and nitrogen metabolic characteristics of size-fractionated microorganisms in floating bed restoration area
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作者 Yi SHI Rui ZHAO +1 位作者 Lingfeng HUANG Wenjing ZHANG 《Journal of Oceanology and Limnology》 2026年第1期184-200,共17页
Ecological floating bed is an important biological remediation method for water pollution control.During the removal of excess nutrients and pollutants,changes in environmental factors affect the characteristics of mi... Ecological floating bed is an important biological remediation method for water pollution control.During the removal of excess nutrients and pollutants,changes in environmental factors affect the characteristics of microorganisms in aquatic ecosystems.To understand the influences of ecological floating beds on size-fractionated microorganisms,we investigated the community assembly and nitrogen metabolic characteristics of three size-fractionated microorganism groups in the ecological floating bed area,using 18S rDNA,16S rDNA metabarcoding,and metagenomic sequencing techniques.Firstly,we discovered substantial differences between size-fractionated groups in the diversity and compositions of both microeukaryotic and bacterial communities,as well as the influences of floating beds on specific groups.The floating beds appeared to provide more habitats for heterotrophs and symbiotes while potentially inhibiting the growth of certain phytoplankton(cyanobacteria).Secondly,we observed that microeukaryotic and bacterial communities were predominantly influenced by stochastic and deterministic processes,respectively,and they both exhibited distinct patterns across different size-fractionated groups.Notably,microeukaryotic community assembly demonstrated a greater sensitivity to ecological floating beds,as indicated by an increase in dispersal limitation processes.Finally,the nitrogen metabolism functional genes revealed that microbes associated with large-sized particles played a crucial role in dissimilatory nitrate reduction to ammonium(DNRA)and denitrification processes within the floating bed area,thereby facilitating the removal of excess nitrogen nutrients from the water.In contrast,freeliving microorganisms from small-sized groups were linked mainly to the genes involved in nitrogen assimilation and assimilatory nitrate reduction to ammonium(ANRA)processes.These findings help understand the impact of ecological floating beds on the diversity and functional characteristics of microorganism communities in different size-fractionated groups. 展开更多
关键词 size-fractionated MICROORGANISM METAGENOMIC nitrogen metabolism assembly process ecological floating bed
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Effects of Nitrogen Rate and Planting Density on the Growth and Quality of Tobacco Cultivar Chuxue 80
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作者 Xiao WANG Jiuchang SHI +4 位作者 Guangpu ZHANG Changhe CHENG Guanghua HUANG Huan HUANG Baoming QIAO 《Asian Agricultural Research》 2026年第1期36-38,45,共4页
[Objectives]To investigate the effects of different planting densities and nitrogen application rates on the yield and quality of the tobacco cultivar Chuxue 80.[Methods]A field experiment was conducted in Hubei Provi... [Objectives]To investigate the effects of different planting densities and nitrogen application rates on the yield and quality of the tobacco cultivar Chuxue 80.[Methods]A field experiment was conducted in Hubei Province,evaluating various combinations of planting density and nitrogen rate for Chuxue 80.[Results]At the maturity stage,the TN1 treatment(5 kg N per 667 m^(2) with a density of 1900 plants per 667 m^(2))demonstrated the most favorable agronomic performance.The TN9 treatment(11 kg N per 667 m^(2) with a density of 1110 plants per 667 m^(2))achieved the highest wrapper tobacco yield and output value.Meanwhile,the TN5 treatment(8 kg N per 667 m^(2) with a density of 1515 plants per 667 m^(2))resulted in the best smoking quality.[Conclusions]The TN9 treatment,with a planting density of 1110 plants per 667 m^(2) and a nitrogen application rate of 11 kg per 667 m^(2),is recommended as the optimal cultivation practice for Chuxue 80 in Hubei Province. 展开更多
关键词 TOBACCO nitrogen application rate Planting density Agronomic traits Smoking quality
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Effects of nighttime warming and nitrogen addition on phytoplankton biomass in a submerged macrophytes-dominated freshwater wetland
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作者 Yaru Lyu Jiayin Feng +9 位作者 Wenjing Ma Chao Wang Mengyu Yan Zixuan Yang Yunpeng Guo Jinhua Zhang Hongpeng Wang Jingyi Ru Xueli Qiu Shiqiang Wan 《Journal of Environmental Sciences》 2026年第1期721-730,共10页
Climate warming and atmospheric nitrogen(N)deposition have profound influences on the terrestrial biosphere.However,how these two global change drivers affect phytoplankton which are important primary producers in wet... Climate warming and atmospheric nitrogen(N)deposition have profound influences on the terrestrial biosphere.However,how these two global change drivers affect phytoplankton which are important primary producers in wetlands with large carbon stocks and complex hydrological fluctuations remain largely unclear.As part of a two-year field experiment in a freshwater wetland,this study was conducted to investigate the effects of nighttime warming and N addition on phytoplankton biomass in the North China Plain.The results showed that neither nighttime warming nor N addition influenced the Shannon-Wiener index of phytoplankton community.Nighttime warming did not change phytoplankton biomass,likely due to the different warming impacts on dominant phyla and in different seasons.Decreased phytoplankton biomass in spring because of the increased water pH and submerged plant coverage was compensated by the enhanced biomass in autumn due to the reduced dissolved oxygen and submerged plant coverage,leading to the neutral change of phytoplankton biomass under warming.Nitrogen addition elevated phytoplankton biomass by 11.6%,which could be attributed to the enhanced nutrient availability and reduced submerged plant coverage.Positive relationships of methane(CH4)emission rates at the water-air interface with phytoplankton biomass indicated the potentially crucial role of phytoplankton in mediating wetland CH4 cycling through photosynthesis-driven metabolisms.The findings suggested the seasonal variation of phytoplankton and their potential responses to nighttime warming and N deposition,which may provide a more accurate basis for assessing the global change-carbon feedback in wetland ecosystems. 展开更多
关键词 Climate warming nitrogen deposition Phytoplankton community Freshwater lake Seasonal variation
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Optimized nitrogen and potassium fertilizers application increases stem lodging resistance and grain yield of oil flax by enhancing lignin biosynthesis
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作者 Xiqiang Li Yuhong Gao +8 位作者 Zhengjun Cui Tingfeng Zhang Shiyuan Chen Shilei Xiang Lingling Jia Bin Yan Yifan Wang Lizhuo Guo Bing Wu 《Journal of Integrative Agriculture》 2026年第2期659-670,共12页
Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassi... Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassium fertilization interactively influence lignin biosynthesis in oil flax stems require further investigation.Therefore,this study aimed to enhance lodging resistance and increase grain yield in oil flax.We examined the interactive effects of different nitrogen (75,150,and 225 kg N ha^(–1)) and potassium (60 and 90 kg K_(2)O ha^(–1)) fertilizer rates on lignin metabolism,lodging resistance,and grain yield during the 2022 and 2023 growing seasons.Results indicated that nitrogen and potassium fertilizer levels and their interactions promoted lignin accumulation,improved lodging resistance,and increased grain yield.Compared to the control (CK),the75–150 kg N ha^(–1) combined with 60 kg K_(2)O ha^(–1) treatments significantly enhanced the activities of key lignin-synthesizing enzymes (tyrosine ammonia-lyase (TAL),phenylalanine ammonia-lyase (PAL),cinnamyl alcohol dehydrogenase (CAD),and peroxidase (POD)) and upregulated the expression of 4CL1 and F5H3 genes,leading to a 29.63–43.30%increase in lignin content,improved stem bending strength and lodging resistance index,and a 23.27–32.34%increase in grain yield.Correlation analysis revealed that nitrogen and potassium fertilizers positively regulated enzyme activities and gene expression related to lignin biosynthesis,thereby facilitating lignin accumulation and enhancing stem mechanical strength and lodging resistance.Positive correlations were observed among lignin-related enzyme activities,gene expression,lodging resistance traits,and grain yield.In summary,the application of 75–150 kg N ha^(–1) in conjunction with 60 kg K_(2)O ha^(–1)promoted lignin biosynthesis and accumulation,enhanced lodging resistance,and increased grain yield in oil flax grown in the dryland farming region of central Gansu,China.Furthermore,this treatment provides a technical basis for cultivating stress-tolerant and high-yield oil flax in arid regions. 展开更多
关键词 oil flax nitrogen fertilizer potassium fertilizer stem lodging resistance lignin biosynthesis YIELD
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Engineering green ammonia photoproduction from nitrogen:Advances,challenges and perspectives
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作者 Ying Tang Yang Song +4 位作者 Juan Jia Zhipeng Liu Hui Zeng Xue Yang Zebao Rui 《Journal of Energy Chemistry》 2026年第1期111-154,I0004,共45页
Green ammonia,produced by harnessing renewable solar energy to split nitrogen,plays a pivotal role in both agricultural practices and forthcoming energy configurations,driving the sustainable development of human soci... Green ammonia,produced by harnessing renewable solar energy to split nitrogen,plays a pivotal role in both agricultural practices and forthcoming energy configurations,driving the sustainable development of human society with zero-carbon emissions.However,nitrogen photoreduction currently faces the challenges of poor activation ability and low yield,and it is still challenging to unravel the intertwined problems in this field and provide direction for its development due to the complex reaction mechanism and multidisciplinary aspects such as photochemistry,catalysis,interface science,and technology.This review focuses on capturing the latest advances in photocatalytic nitrogen-to-ammonia conversion,delving into fundamental principles regarding the process,efficient photocatalysts for practical ammonia synthesis,and well-designed catalytic environments.Besides,this article provides insightful guidelines for analyzing complicated reaction mechanisms and identifying key bottlenecks or specific rate-determining steps,such as reactant activation,interfacial reaction engineering,and hydrogen evolution side reactions.By integrating perspectives from atomic mechanisms,nanoscale photocatalysts,microscale interfacial engineering,and macroscale reaction system design,this review advances the development of nitrogen photoreduction from proof-of-concept discoveries to viable solar-to-chemical conversion technologies,while also providing a valuable entry point for researchers into this burgeoning field. 展开更多
关键词 Green ammonia nitrogen photoreduction Reaction mechanism Photocatalyst design Catalytic environment optimization
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White matter matters inβ-glucocerebrosidase-related pathologies
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作者 Loris Russo Matilde Cescon 《Neural Regeneration Research》 2026年第6期2333-2334,共2页
β-glucocerebrosidase in health and disease:Mutations in theβ-glucocerebrosidase(GBA)gene do cause the rare lysosomal storage disorder Gaucher’s disease(GD)with an estimated global prevalence of 1:200,000(Imbalzano ... β-glucocerebrosidase in health and disease:Mutations in theβ-glucocerebrosidase(GBA)gene do cause the rare lysosomal storage disorder Gaucher’s disease(GD)with an estimated global prevalence of 1:200,000(Imbalzano et al.,2024).GBA is a membrane-bound lysosomalenzyme responsible for glucosylceramide and glucosylsphingosine hydrolysis.When this enzyme is mutated and dysfunctional,its substrates progressively accumulate within cells. 展开更多
关键词 white matter GLUCOSYLCERAMIDE Gaucher s disease GLUCOCEREBROSIDASE glucosylsphingosine lysosomal storage disorder glucocerebrosidase gene
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Self-supervised pre-training based hybrid network for deep gray matter nuclei segmentation
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作者 Yang Deng Jiaxiu Xi +1 位作者 Zhong Chen Lijun Bao 《Magnetic Resonance Letters》 2026年第1期53-65,共13页
The accurate segmentation of deep gray matter nuclei is critical for neuropathological research,disease diagnosis and treatment.Existing methods employ the supervised learning training approach,which requires large la... The accurate segmentation of deep gray matter nuclei is critical for neuropathological research,disease diagnosis and treatment.Existing methods employ the supervised learning training approach,which requires large labeled datasets.It is challenging and time-consuming to obtain such datasets for medical image analysis.In addition,these methods based on convolutional neural networks(CNNs)only achieve suboptimal performance due to the locality of convolutional operations.Vision Transformers(ViTs)efficiently model long-range dependencies and thus have the potentiality to outperform these methods in segmentation tasks.To address these issues,we propose a novel hybrid network based on self-supervised pre-training for deep gray matter nuclei segmentation.Specifically,we present a CNN-Transformer hybrid network(CTNet),whose encoder consists of 3D CNN and ViT to learn local spatial-detailed features and global semantic information.A self-supervised learning(SSL)approach that integrates rotation prediction and masked feature reconstruction is proposed to pre-train the CTNet,enabling the model to learn valuable visual representations from unlabeled data.We evaluate the effectiveness of our method on 3T and 7T human brain MRI datasets.The results demonstrate that our CTNet achieves better performance than other comparison models and our pre-training strategy outperforms other advanced self-supervised methods.When the training set has only one sample,our pre-trained CTNet enhances segmentation performance,showing an 8.4%improvement in Dice similarity coefficient(DSC)compared to the randomly initialized CTNet. 展开更多
关键词 Deep gray matter nuclei segmentation Self-supervised learning Rotation prediction Masked feature reconstruction TRANSFORMER
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Nitrogen addition alleviates negative effects of drought on root growth but aggravates them on leaf growth of Moso bamboo(Phyllostachys edulis)seedlings
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作者 Ge Gao Junyong Xia +5 位作者 Yaowen Xu Xiaogai Ge Aibo Li Ziqing Zhao Zhengcai Li Benzhi Zhou 《Forest Ecosystems》 2026年第1期35-43,共9页
Forest ecosystems are increasingly susceptible to droughts and nitrogen(N)deposition.However,the effects of N addition on the growth of bamboo under drought stress remain unclear.This study conducted a comprehensive f... Forest ecosystems are increasingly susceptible to droughts and nitrogen(N)deposition.However,the effects of N addition on the growth of bamboo under drought stress remain unclear.This study conducted a comprehensive factorial experiment to investigate the combined effects of drought and N addition on the growth of Moso bamboo(Phyllostachys edulis)seedlings.Six treatment combinations were established:0 mg·kg^(-1) N with 80%–85%field capacity(FC)soil moisture,0 mg·kg^(-1) N with 50%–55%FC,0 mg·kg^(-1) N with 30%–35%FC,100 mg·kg^(-1) N with 80%–85%FC,100 mg·kg^(-1) N with 50%–55%FC,and 100 mg·kg^(-1) N with 30%–35%FC.The results revealed that drought altered the soil microbial community structure and significantly reduced the biomass of Moso bamboo seedlings.Notably,N addition mitigated the adverse effects of drought on bamboo growth in general.Specifically,N addition alleviated the negative effects of drought on root biomass but aggravated them on leaf biomass of Moso bamboo seedlings,and with the intensification of drought stress,this effect was weakened.Furthermore,sucrose and urease exerted dominant and direct influences on the total biomass.The results underscore the pivotal role of N in facilitating plant drought tolerance,suggesting that the interplay between drought and N addition in plant growth should be considered in the context of changing environmental conditions,and offering novel perspectives on sustainable management strategies for bamboo forests. 展开更多
关键词 Drought stress nitrogen(N)deposition Moso bamboo Soil microbial community Plant biomass
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Nitrogen and oxygen isotopes in nitrate and nitrite in the polluted surface waters from the Arno River Basin(Central Italy)
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作者 Lorenzo Chemeri Barbara Nisi +5 位作者 Andrea Pierozzi Jacopo Cabassi Marco Taussi Stefania Venturi Antonio Delgado Huertas Orlando Vaselli 《Journal of Environmental Sciences》 2026年第1期250-262,共13页
The Arno River Basin(Central Italy)is affected by a considerable anthropogenic pressure due to the presence of large cities and widespread industrial and agricultural practices.In this work,26 water samples from the A... The Arno River Basin(Central Italy)is affected by a considerable anthropogenic pressure due to the presence of large cities and widespread industrial and agricultural practices.In this work,26 water samples from the Arno River and its main tributaries were analyzed to assess the water pollution status.The geochemical composition of the Arno River changes from the source(dominated by a Ca-HCO_(3) facies)to the mouth(where a Na-Cl(SO4)chemistry prevails)with an increasing quality deterioration,as suggested by the Chemical Water Quality Index,due to anthropogenic contributions and seawater intrusion before flowing into the Ligurian Sea.The Ombrone and Usciana tributaries introduce anthropogenic pollutants into the Arno River,whilst Elsa tributary supplies significant contents of geogenic sulfate.The concentrations of dissolved nitrate and nitrite(up to 63 and 9 mg/L,respectively)and the respective isotopic values of𝛿15N and𝛿18O were also determined to understand origin and fate of the N-species in the Arno River Basin surface waters.The combined application of𝛿15N-NO_(3) and𝛿18O-NO_(3) and N-source apportionment modelling allowed the identification of soil organic nitrogen and sewage and domestic wastes as primary sources for dissolved NO_(3)-.The𝛿15N-NO_(2) and𝛿18O-NO_(2) values suggest that the nitrification process affects the ARB waters,thus controlling the abundances and proportion of the N-species.Our work indicates that additional efforts are needed to improve management strategies to reduce the release of nitrogenated species to the surface waters of the Arno River Basin,since little progress has been made from the early 2000s. 展开更多
关键词 River geochemistry Water pollution nitrogen stable isotopes Surface water management Water quality Anthropogenic pollution
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Delayed microglial depletion protects against white matter injury following neonatal cerebral hemorrhage in mice
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作者 Xiaoxiao Jing Xiaoli Zhang +13 位作者 Hongwei Li Yu Yang Zuhang Zhao Yuandan Li Jinjin Zhu Yiran Xu Jing Yuan Tiantian He Chen Zhang Juan Song Xin Zhao Xiaoyang Wang Changlian Zhu Falin Xu 《Neural Regeneration Research》 2026年第6期2621-2631,共11页
Germinal matrix hemorrhage in preterm neonates often leads to white matter injury,contributing to long-term neurodevelopmental impairments.As resident brain immune cells,microglia play a complex role in injury respons... Germinal matrix hemorrhage in preterm neonates often leads to white matter injury,contributing to long-term neurodevelopmental impairments.As resident brain immune cells,microglia play a complex role in injury response,including inflammation and repair.Although colony-stimulating factor 1 receptor inhibitors such as PLX5622 enable the selective depletion of microglia,their therapeutic potential in neonatal germinal matrix hemorrhage remains underexplored.Here,we used a collagenase-induced germinal matrix hemorrhage model in postnatal day 5 mice,and intraperitoneally administered PLX562272 hours post-germinal matrix hemorrhage to achieve targeted,temporary microglial depletion during the peak injury response.We then assessed the effects of this delayed intervention on oligodendrocyte lineage cell maturation,white matter integrity,and neurobehavioral outcomes.Additionally,RNA sequencing data from a germinal matrix hemorrhage rat model were analyzed using weighted gene co-expression network analysis to identify the critical phases for interventions.RNA sequencing data revealed a critical period in which key synaptic functions declined while immune responses intensified post-germinal matrix hemorrhage,thus pinpointing the critical response phases for potential interventions.Delayed PLX5622 treatment effectively depleted activated microglia,protecting against white matter injury and enhancing oligodendrocyte lineage cell maturation and myelination in subcortical white matter regions.Moreover,magnetic resonance imaging analysis revealed reduced brain lesion volumes in treated mice.Behaviorally,PLX5622-treated mice exhibited significant improvements in motor coordination and reduced hyperactivity compared with vehicle-treated germinal matrix hemorrhage model mice.These findings suggest that,when timed to avoid interference with initial oligodendrocyte lineage cell proliferation,targeted microglial depletion with PLX5622 significantly mitigates white matter damage and improves neurobehavioral outcomes in neonatal germinal matrix hemorrhage.The present study highlights the therapeutic potential of selectively modulating microglial reactivity to support neurodevelopment in preterm infants with brain injury. 展开更多
关键词 colony-stimulating factor 1 receptor germinal matrix hemorrhage microglia MYELINATION neonatal brain oligodendrocyte lineage cell PLX5622 white matter injury
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Optimizing nitrogen application and planting density improves yield and resource use efficiency via regulating canopy light and nitrogen distribution in rice
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作者 Zichen Liu Liyan Shang +8 位作者 Shuaijun Dai Jiayu Ye Tian Sheng Jun Deng Ke Liu Shah Fahad XiaohaiTian Yunbo Zhang Liying Huang 《Journal of Integrative Agriculture》 2026年第1期81-91,共11页
Coordinating light and nitrogen(N)distribution within a canopy is essential for improving rice yield and resource use efficiency.However,limited research has examined light and N distribution in response to planting d... Coordinating light and nitrogen(N)distribution within a canopy is essential for improving rice yield and resource use efficiency.However,limited research has examined light and N distribution in response to planting density and N rate,and their relationships with grain yield,radiation use efficiency(RUE),and N use efficiency for grain production(NUEg)in rice.A two-year field experiment was conducted with two hybrid varieties under three N levels,0 kg ha^(-1)(N1),90 kg ha^(-1)(N2)and 180 kg ha^(-1)(N3),and two planting densities,22.2 hills m-2(D1)and 33.3 hills m^(-2)(D2).Results showed 3.4%higher yield and 4.4%higher NUEg under N2D2 compared with N3D1.The extinction coefficient for N(K_(N))and light(K_(L))and their ratio(K_(N)/K_(L))at heading stage were significantly influenced by N rate,planting density,and their interaction.K_(N)decreased with the increase of N input or planting density.Compared to N1,K_(N)decreased by 43.5 and 58.8%under N2 and N3,respectively,while K_(N)under D2 decreased by 16.0%compared to D1.Higher K_(L)and K_(N)/K_(L)values occurred under low N rates,with opposite trends under high N rates.Increased planting density led to decreased K_(L)and K_(N)/K_(L)values.N2D2 demonstrated higher K_(L)and K_(N),and thus comparable K_(N)/K_(L),compared to N3D1.Correlation analysis revealed K_(L)negatively correlated with RUE,while K_(N)and K_(N)/K_(L)positively correlated with NUEg.These findings indicate that increasing planting density under reduced N input could maintain rice yield while enhancing resource use efficiency through regulation of canopy light and N distribution. 展开更多
关键词 canopy light and N distribution nitrogen input planting density high yield and high efficiency hybrid rice
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Long-term manure amendment enhances N_(2)O emissions from acidic soil by alleviating acidification and increasing nitrogen mineralization
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作者 Lei Wu Jing Hu +4 位作者 Muhammad Shaaban Jun Wang Kailou Liu Minggang Xu Wenju Zhang 《Journal of Integrative Agriculture》 2026年第1期262-272,共11页
Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse... Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse gas N_(2)O emissions from acidic soil mediated by long-term manure application remain poorly understood. Herein, we investigated N_(2)O emission and its linkage with gross N mineralization and nitrification rates, as well as nitrifying and denitrifying microbes in an acidic upland soil subjected to 36-year fertilization treatments, including an unfertilized control(CK), inorganic fertilizer(F), 2× rate of inorganic fertilizer(2F), manure(M), and the combination of inorganic fertilizer and manure(FM) treatments. Compared to the CK treatment(1.34 μg N kg^(-1) d^(-1)), fertilization strongly increased N_(2)O emissions by 34-fold on average, with more pronounced increases in the manure-amendment(10.6-169 μg N kg^(-1) d^(-1)) than those in the inorganic fertilizer treatments(3.26-5.51 μg N kg^(-1) d^(-1)). The manure amendment-stimulated N_(2)O emissions were highly associated with increased soil pH, mean weight diameter of soil aggregates, substrate availability(e.g., particulate organic carbon, NO_(3)^(-)and available phosphorus), gross N mineralization rates, denitrifier abundances and the(nirK+nirS)/nosZ ratio. These findings suggest that the increased N_(2)O emissions primarily resulted from alleviated acidification, increased substrate availability and improved soil structure, thus enhancing microbial N mineralization and favoring N_(2)O^(-)producing denitrifiers over N_(2)O consumers. Moreover, ammonia-oxidizing bacteria(AOB) rather than ammonia-oxidizing archaea(AOA) positively correlated with soil NO_(3)^(-)concentration and N_(2)O emissions, indicating that nitrification indirectly contributed to N_(2)O production by supplying NO_(3)^(-)for denitrification. Collectively, manure amendment potentially stimulates N_(2)O emissions, primarily resulting from alleviated soil acidification and increased substrate availability, thus enhancing N mineralization and denitrifier-mediated N_(2)O production. Our findings suggest that consideration should be given to the greenhouse gas budgets of agricultural ecosystems when applying manure for managing the pH and fertility of acidic soils. 展开更多
关键词 long-term manure amendment N_(2)O emission nitrogen mineralization denitrification (nirK+nirS)/nosZ
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Soil nitrogen dynamics regulate differential nitrogen uptake between rice and upland crops
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作者 Shending Chen Ahmed S.Elrys +5 位作者 Siwen Du Wenyan Yang Zucong Cai Jinbo Zhang LeiMeng Christoph Müller 《Journal of Integrative Agriculture》 2026年第1期302-312,共11页
Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and th... Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and their impact on crop nitrogen uptake remain poorly understood.The N dynamics and impact on crop N uptake determine the downstream environmental pollution from nitrogen fertilizer.To address this poor understanding,we analyzed 2,044 observations of gross nitrogen transformation rates in soils from 136 studies to examine nitrogen dynamics in both systems and their effects on nitrogen uptake in rice and upland crops.Our findings revealed that nitrogen mineralization and autotrophic nitrification rates are lower in paddies than in upland soil,while dissimilatory nitrate reduction to ammonium is higher in paddies,these differences being driven by flooding and lower total nitrogen content in paddies.Rice exhibited higher ammonium uptake,while upland crops had over twice the nitrate uptake.Autotrophic nitrification stimulated by p H reduced rice nitrogen uptake,while heterotrophic nitrification enhanced nitrogen uptake of upland crops.Autotrophic nitrification played a key role in regulating the ammonium-to-nitrate ratio in soils,which further affected the balance of plant nitrogen uptake.These results highlight the need to align soil nitrogen dynamics with crop nitrogen preferences to maximize plant maximize productivity and reduce reactive nitrogen pollution. 展开更多
关键词 paddy soil upland soil plant nitrogen uptake N mineralization NITRIFICATION ^(15)N tracing study
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Response of soil carbon emissions to warming,rainfall increase and nitrogen addition in cold-temperate coniferous forests under global climate change
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作者 Yanan Jian Qiuliang Zhang +2 位作者 Tairui Liu Xin Zhang Shuai Hao 《Journal of Forestry Research》 2026年第1期169-187,共19页
Changes in the soil environment induced by major global changes in climate are affecting carbon emissions in cold-temperate coniferous forests.A randomized block experiment simulating warming,rainfall increase and nit... Changes in the soil environment induced by major global changes in climate are affecting carbon emissions in cold-temperate coniferous forests.A randomized block experiment simulating warming,rainfall increase and nitrogen addition in a Larix gmelinii forest was carried out to study the effects on soil carbon,nitrogen,and CO_(2)flux during the thawing,growing,and freezing periods.Our study found that warming(0-2.0℃)increased soil organic carbon(SOC)and total nitrogen(STN),dissolved organic carbon(DOC)and dissolved organic nitrogen(DON),and microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN).Warming played a direct role in regulating soil CO_(2)emissions,stimulated microbial and plant root respiration and soil CO_(2)flux rapidly increased.Rainfall increase initially increased soil carbon and nitrogen,but a 30%increase in mean annual rainfall caused losses of SOC,STN,DOC,and DON,while MBC and MBN accumulated.Soil CO_(2)emissions were regulated by MBC after an increase in rainfall,excess moisture inhibited microbial activity,and soil CO_(2)flux showed a trend of R2(20%rainfall increase)>R1(10%rainfall increase)>CK(control)>R3(30%rainfall increase).The addition of nitrogen increased SOC,STN,DOC,DON,MBC and MBN.Soil CO_(2)flux progressively decreased with nitrogen inputs(2.5,5.0 and 10.0 g m^(-2)a^(-1)),as more N intensified plant-microbe competition.Nitrogen addition indirectly regulated soil CO_(2)emissions by altering SOC and STN,with MBC and MBN acting as secondary regulators.The results highlight the role of cold-temperate coniferous forest soils in predicting carbon-climate feedback in high-latitude forest permafrost regions. 展开更多
关键词 Soil carbon and nitrogen Soil CO_(2)emissions Global climate change Response mechanism Larix gmelinii
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