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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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In-situ generated ordered-disordered Bi_(2)WO_(6)homojunction for enhanced photocatalytic nitrogen fixation performance
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作者 ZHANG Lulu HOU Yahui +2 位作者 LU Yunfei LI Rui LIU Jianxin 《无机化学学报》 北大核心 2026年第3期606-616,共11页
A collection of ordered-disordered Bi_(2)WO_(6)homojunction catalysts was prepared in-situ through a facile one-step hydrothermal process,and their photocatalytic nitrogen fixation to synthesize ammonia performance wa... A collection of ordered-disordered Bi_(2)WO_(6)homojunction catalysts was prepared in-situ through a facile one-step hydrothermal process,and their photocatalytic nitrogen fixation to synthesize ammonia performance was evaluated.Results showed that ordered-disordered Bi_(2)WO_(6)(OD-2)obtained by adding 1.5 mL of ethylene glycol during preparation exhibited the optimal nitrogen fixation performance,with a nitrogen fixation rate of 114.92μmol·g^(-1)·h^(-1).However,its crystal counterpart,Bi_(2)WO_(6)(BWO),lacked nitrogen-fixation activity.In-situ diffuse reflectance-Fourier transform infrared technique(DR-FTIR),electrochemical tests,and energy band structure analysis confirmed that the surface disordered structure in OD-2 not only promoted nitrogen activation but also enabled the effective separation of photogenerated electron-hole pairs at the ordered-disordered interface,facilitating the interface electrons transfer to the surface disordered structure of OD-2 and reacting with N_(2) adsorbed on the disordered structure,thereby promoting the smooth progress of the nitrogen fixation reaction. 展开更多
关键词 ordered-disordered homojunction Bi_(2)WO_(6) photocatalytic nitrogen fixation
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Comparative Study on the Efficacy of Closed Reduction and Kirschner Wire Fixation versus Open Reduction and Plate Fixation in the Treatment of Hand Surgery Fractures
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作者 Weishun Wang 《Journal of Clinical and Nursing Research》 2026年第2期81-87,共7页
Objective: To investigate the therapeutic advantages of closed reduction and Kirschner wire fixation versus open reduction and plate fixation in patients with hand surgery fractures. Methods: The sample was collected ... Objective: To investigate the therapeutic advantages of closed reduction and Kirschner wire fixation versus open reduction and plate fixation in patients with hand surgery fractures. Methods: The sample was collected from May 2021 to May 2025, consisting of 80 patients with hand surgery fractures. These patients were randomly divided into two groups using the red and blue ball method: the plate fixation group (40 cases, treated with open reduction and plate fixation) and the Kirschner wire fixation group (40 cases, treated with closed reduction and Kirschner wire fixation). The therapeutic effects between the two groups were randomly compared. Results: The Kirschner wire fixation group outperformed the plate fixation group in all indicators except for hand function scores (p < 0.05). There was no statistically significant difference in hand function scores between the two groups (p > 0.05). Conclusion: Compared with open reduction and plate fixation, closed reduction and Kirschner wire fixation for patients with hand surgery fractures achieves a more pronounced therapeutic effect, with advantages such as less trauma, shorter operation time, less bleeding, and a lower incidence of complications. It is suitable for hand surgery fractures with good stability. Open reduction and plate internal fixation have greater advantages in complex fractures and cases requiring high stability, and are worthy of promotion and application. 展开更多
关键词 Closed reduction and Kirschner wire fixation Open reduction and plate fixation Hand surgery fractures
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Research on Reactive Power Control Strategy for Small Extinction Angle Operation of Hybrid Commutation Converters
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作者 Jiaxing Ning Xiaoguang Wei +3 位作者 Zhichang Yuan Longlong Chen Hui Du Zhanqing Yu 《Protection and Control of Modern Power Systems》 2026年第1期26-39,共14页
Hybrid commutation converters(HCCs)utilizing reverse-blocking integrated gate commutation thyristors(IGCTs)have gained significant attention due to their immunity to commutation failure.Leveraging the recovery enhance... Hybrid commutation converters(HCCs)utilizing reverse-blocking integrated gate commutation thyristors(IGCTs)have gained significant attention due to their immunity to commutation failure.Leveraging the recovery enhancement characteristics of IGCTs,HCCs demonstrate superior performance at reduced extinction angles,thereby minimizing reactive power consumption.This study presents a comprehensive investigation into reactive power control strategies for HCCs operating at small extinction angles.First,the topological configuration and commutation principle of HCC are elucidated.Subsequently,the mechanism of HCC reactive power control is analyzed,and a reactive power control strategy is proposed by combining the converter transformer taps with extinction angles.Moreover,the relationship between transformer taps and reactive power exchange under different rated extinction angles is calculated,and the theoretically rated extinction angle is proposed.Finally,to validate the proposed control strategy,a four-terminal ultra-high voltage direct current power grid incorporating HCC technology is modeled and sim-ulated using PSCAD/EMTDC.The simulation results demonstrate that the proposed strategy effectively supports AC systems by reducing reactive power absorption in HCCs,while simultaneously exhibiting enhanced reli-ability and economic efficiency. 展开更多
关键词 Commutation failure extinction angle HCC reactive power tap position
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Opportunistic keystone diazotrophs from co-occurrence networks drive biological nitrogen fixation in peanut/cotton intercropping systems
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作者 Shijie Zhang Yingchun Han +10 位作者 Guoping Wang Lu Feng Yaping Lei Shiwu Xiong Beifang Yang Xiaoyu Zhi Minghua Xin Yahui Jiao Xiaofei Li Yabing Li Zhen Jiao 《Journal of Integrative Agriculture》 2026年第3期1209-1222,共14页
Legume-based intercropping enhances asymbiotic biological nitrogen fixation(BNF);however,the underlying mechanisms remain unclear,including the roles of soil keystone diazotroph taxa with varying niche breadths.A fiel... Legume-based intercropping enhances asymbiotic biological nitrogen fixation(BNF);however,the underlying mechanisms remain unclear,including the roles of soil keystone diazotroph taxa with varying niche breadths.A field experiment was conducted to evaluate soil BNF variations between rhizosphere and bulk soils in peanut/cotton intercropping systems and monocultures.BNF activities were measured by nitrogen fixation rates,nitrogenase activity,and nifH gene abundance.Phylogenetic null models,co-occurrence networks,and niche breadth analysis were applied to investigate the roles of diazotrophic keystone taxa and their ecological niches.Rhizosphere soils exhibited 7.8–125.5%higher BNF potentials than bulk soils,whereas intercropping systems showed 11.6–323.0%increases over monocultures for nitrogen fixation rate,nitrogenase activity,and nifH gene abundance(all P<0.05).Diazotrophic community composition and diversity differed significantly,with Proteobacteria(excluding Alphaproteobacteria)enriched in intercropping and rhizosphere soils,while Cyanobacteria and Firmicutes were less abundant.Deterministic processes,particularly heterogeneous selection,dominated community assembly in the rhizosphere(91.9%)and intercropping soils(86.3%).The co-occurrence networks consistently revealed more complex and interconnected communities in intercropping and rhizosphere soils that were dominated by opportunistic diazotrophs(78.8–85.9%),followed by specialists(10.2–18.5%)and generalists(1.38–3.80%).Keystone taxa,including opportunists such as Azoarcus,Azohydromonas,and Steroidobacter,and generalists like Pseudomonas and Azotobacter,correlated positively with microbial biomass carbon and nitrate nitrogen,contributing to enhanced BNF.Peanut/cotton intercropping enhances BNF by selectively enriching the keystone diazotrophic taxa with varying ecological roles,particularly opportunists and generalists.Such targeted intercropping strategies can optimize BNF,improve soil fertility,and promote sustainable agricultural production. 展开更多
关键词 biological nitrogen fixation community assembly habitat ecotypes keystone diazotroph taxa
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Facile method for creating frustrated Lewis pairs in g-C_(3)N_(4) to enhance photocatalytic nitrogen fixation performance
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作者 Lanxin Wang Kaiwei Liang +2 位作者 Xuelian Yu Guocheng Lv Libing Liao 《Chinese Chemical Letters》 2026年第1期622-625,共4页
The rate-limited activation of N≡N triple bonds with high bond energies has been a bottleneck in photoctalytic nitrogen fixation.Here,polymeric carbon nitride with frustrated Lewis pairs(FLPs) was constructed by inse... The rate-limited activation of N≡N triple bonds with high bond energies has been a bottleneck in photoctalytic nitrogen fixation.Here,polymeric carbon nitride with frustrated Lewis pairs(FLPs) was constructed by inserting electron-deficient magnesium into g-C_(3)N_(4)(CN).The synergistic interactions between Mg and amino groups in CN led to a 7.2 fold increase in the photoreactivity of nitrogen(N_(2)) fixation by carbon nitride. 展开更多
关键词 N_(2)fixation PHOTOCATALYTIC FLPs AMMONIA g-C_(3)N_(4)
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Minimally invasive four-point scleral refixation for dislocated 4-haptic IOL by horizontal mattress sutures and Hoffman pockets
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作者 Zhao-Liang Zhang Jia-Hui Shen +3 位作者 Jun-Yi Chen Qin-Tuo Pan Xu-Ting Hu Zong-Duan Zhang 《International Journal of Ophthalmology(English edition)》 2026年第3期483-489,共7页
AIM:To evaluate the clinical outcomes of a new minimally invasive technique using horizontal mattress sutures and Hoffman pockets for four-point refixation of dislocated fourhaptic intraocular lenses(IOLs).METHODS:Thi... AIM:To evaluate the clinical outcomes of a new minimally invasive technique using horizontal mattress sutures and Hoffman pockets for four-point refixation of dislocated fourhaptic intraocular lenses(IOLs).METHODS:This retrospective consecutive case series included eyes with dislocated Akreos AO60 IOLs underwent scleral refixation using a horizontal mattress doubleneedle suture technique with intralamellar knot burial via Hoffman pockets.Clinical outcomes assessed included pre-and postoperative best-corrected visual acuity(BCVA),intraocular pressure(IOP),spherical equivalent(SE),suture duration,IOL centration,and perioperative complications.RESULTS:A total of 10 eyes from 10 patients(6 males)were included.The mean age at the time of IOL refixation was 53.10±13.07y(range:28-68y).The mean interval between initial IOL implantation and dislocation was 8.44±3.54y.The mean postoperative follow-up duration was 11.45±10.30mo.Surgical time averaged 15.3±1.77min,with no intraoperative complications.The mean axial length was 27.16±4.35 mm,with high myopia(HM)as the leading comorbidity(4/10 eyes).Postoperative BCVA significantly improved compared to preoperative values(P=0.025).Postoperative SE was significantly improved compared with preoperative(P=0.01).All IOLs remained centered throughout follow-up.CONCLUSION:This minimally invasive four-point scleral fixation technique offers a safe and effective refixation strategy for dislocated four-haptic IOLs.The horizontal mattress suture configuration combined with Hoffman pockets facilitates durable centration,avoids conjunctival dissection,and could be adopted into routine surgical practice. 展开更多
关键词 intraocular lens dislocation four-haptic intraocular lens intraocular lens refixation scleral fixation horizontal mattress suture Hoffman pocket minimally invasive ophthalmic surgery
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Cu doping induced lattice distortion and oxygen vacancy formation in PbBiO_(2)Br:Band structure modulation enhances photocatalytic nitrogen fixation and pollutant degradation performance
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作者 Shude Yuan Yekang Zheng +6 位作者 Yuxin Chu Chuanqi Xia Ruoyu Dong Jiating Xu Botao Teng Ying Wu Yiming He 《Green Energy & Environment》 2026年第1期211-223,共13页
Photocatalytic nitrogen fixation has emerged as a sustainable alternative for ammonia synthesis,playing a crucial role in alleviating energy shortages and environmental pollution.In this study,PbBiO_(2)Br was applied ... Photocatalytic nitrogen fixation has emerged as a sustainable alternative for ammonia synthesis,playing a crucial role in alleviating energy shortages and environmental pollution.In this study,PbBiO_(2)Br was applied to photocatalytic nitrogen fixation for the first time,and its photocatalytic performance was effectively enhanced through Cu doping.The catalyst was synthesized via a simple reduction method,and its morphology,structure,and physicochemical properties were systematically investigated using various characterization techniques and density functional theory calculations.The results revealed that the incorporation of Cu2+partially replaced Pb2+,inducing lattice distortion in PbBiO_(2)Br,promoting the formation of oxygen vacancies,and modifying its electronic band structure.Specifically,Cu doping led to a slight bandgap narrowing,a reduction in work function,and a significant upward shift in the conduction band position.These changes enhanced light absorption,facilitated charge carrier migration and separation,and improved the reduction ability of photogenerated electrons.Moreover,Cu doping promoted N_(2)adsorption and activation.Consequently,the photocatalytic nitrogen fixation performance of Cu-doped PbBiO_(2)Br was significantly enhanced,achieving an optimal nitrogen fixation rate of 293μmol L^(−1)g^(−1)h^(−1),which is 3.6 times higher than that of pristine PbBiO_(2)Br.Additionally,Cu–PbBiO_(2)Br also showed good activity in the photocatalytic degradation of RhB,with a degradation rate 4.6 times higher than that of PbBiO_(2)Br.This work offers new insights into the application of PbBiO_(2)Br in photocatalytic nitrogen fixation and offers valuable guidance for the development of highly efficient nitrogen fixation materials in the future. 展开更多
关键词 PbBiO_(2)Br Cu doping Oxygen vacancy Charge separation Photocatalytic N_(2)fixation
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CO_(2) utilization and fixation in biomass-derived furanics conversion:Thermochemical and electrochemical pathways
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作者 Saeideh Gharouni Fattah Sabah Karimi +5 位作者 Shaoyu Yuan Zheng Li Mohammad Jalal Zohuriaan-Mehr Lu Lin Xianhai Zeng Buxing Han 《Green Energy & Environment》 2026年第1期1-22,共22页
Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The appro... Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The approach to biomass,as the only true full-scale alternative to fossil resources,is progressing rapidly.Converting biomass into furanic compounds,as versatile platform chemicals for synthesizing a wide range of bio-based products is the cornerstone of sustainable technologies.The extensive body of this review combines the biomass valorization to furanic compounds by CO_(2)utilization and furanic compounds conversion by CO_(2)fixation.These processes can be strategically applied through both‘thermochemical’and‘electrochemical’pathways,by utilizing CO_(2)from the atmosphere or industrial emission point and returning it to the natural carbon cycle.In the thermochemical pathway CO_(2)acts as a carbon source(carboxylation and polymerization)or active reaction assistant in the biomass conversion(CO_(2)-assisted conversion),without altering its oxidation state,facilitating the synthesis of valuable products and polymers.Conversely,in the electrochemical pathway,CO_(2)can be used as a carbon source(electrocarboxylation)to give the corresponding carboxylic acid,or it can undergo reduction,yielding methanol,carbon monoxide(CO),formic acid,and analogous compounds,while on the other side,furanic compounds undergo oxidation yielding high-value-added chemicals.Finally,potential future research directions are suggested to promote CO_(2)utilization and fixation in the valorization of biomass-derived furanic compounds,and challenges facing further research are highlighted. 展开更多
关键词 CO_(2)utilization and fixation Biomass valorization Furanic compounds Thermochemical and electrochemical pathways Renewable and sustainable resources
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Bi-Bi_(2)Ti_(2)O_(7) ohmic junction:Dual electron channels driving efficient photocatalytic nitrogen fixation
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作者 Pengkun Li Runjie Wu +5 位作者 Shuai Gao Zeping Qin Mingming Sun Changzheng Wang Wenming Sun Qiang Wang 《Chinese Chemical Letters》 2026年第1期563-569,共7页
Photocatalysis uses solar energy to convert nitrogen and water directly into ammonia,helping reduce dependence on fossil fuels and offering a way to integrate the nitrogen cycle into a clean energy network.Ohmic junct... Photocatalysis uses solar energy to convert nitrogen and water directly into ammonia,helping reduce dependence on fossil fuels and offering a way to integrate the nitrogen cycle into a clean energy network.Ohmic junctions between metals and semiconductors have demonstrated significant advantages in enhancing stability and reducing carrier recombination,but their application in photocatalytic nitrogen fixation is limited due to the difficulty of work function matching and the complexity of fabrication processes.In this study,density functional theory(DFT) calculations were used to confirm the work function matching between Bi and Bi_(2)Ti_(2)O_(7)(BTO),ensuring the formation of an Ohmic junction.A Bi-Bi_(2)Ti_(2)O_(7)(B-BTO) composite was successfully synthesized via a one-step hydrothermal method,using bismuth nitrate and titanium sulfate as precursors.Compared to pure BTO,the B-BTO heterojunction,driven by dual electron injection from both metal Bi and BTO,significantly increased the ammonia synthesis rate to 686.95 μmol g^(-1)h^(-1),making it the most active nitrogen fixation material among similar pyrochlorebased catalysts to date.The differential charge density calculations,photocurrent(i-t) measurements,and photoluminescence(PL) tests further validate the role of Ohmic contacts in enhancing charge transfer and prolonging carrier lifetimes.This research provides valuable insight into the application of Ohmic junctions in photocatalytic nitrogen fixation and contributes to advancements in this field. 展开更多
关键词 PHOTOCATALYTIC N_(2)fixation Ohmic junction Dual electron channels Bi_(2)Ti_(2)O_(7)
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DNA methylation regulates the extinction of fear memory 被引量:1
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作者 Le Jiang Rui-Xue Ma +11 位作者 Er-Shu He Xiao-Ye Zheng Xin Peng Wen-Hao Ma Ying Li Han-Wei li Xue-Yan Zhang Jie-Yu Ji Yan-Jiao Li Shang-Lan Qu Li-Juan Li Zhi-Ting Gong 《World Journal of Psychiatry》 2025年第7期273-283,共11页
BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge... BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge.Fear conditioning and extinction in animal models offer insights into its mechanisms.Our previous research indi-cates that DNA methyltransferases play a role in fear memory renewal.AIM To investigate the role of DNA methylation in the extinction of fear memory,with the goal of identifying potential strategies to enhance the efficacy of exposure therapy for fear-related disorders.METHODS This study investigated the role of DNA methylation in fear memory extinction in mice.DNA methylation was manipulated using N-phthalyl-L-tryptophan(RG108)to reduce methylation and L-methionine injections to enhance it.Neuronal activity,and dendritic spine density was measured following extinction training.RESULTS RG108 suppressed extinction,reduced spine density,and inhibited neuronal activity.Methionine injections facilitated extinction.CONCLUSION DNA methylation is crucial for fear memory extinction.Enhancing methylation may improve the efficacy of exposure therapy,offering a potential strategy to treat fear-related disorders. 展开更多
关键词 RG108 DNA methylation Fear memory Exposure therapy extinction
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Local Electric Fields Coupled with Cl^(−)Fixation Strategy for Improving Seawater Oxygen Reduction Reaction Performance
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作者 Yu-Rong Liu Miao Zhang +8 位作者 Yan-Hui Yu Ya-Lin Liu Jing Li Xiao-Dong Shi Zhen-Ye Kang Dao-Xiong Wu Peng Rao Ying Liang Xin-Long Tian 《电化学(中英文)》 北大核心 2025年第9期46-55,共10页
Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field c... Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field coupled with chloride ions(Cl-)fixation strategy in dual single-atom catalysts(DSACs)was proposed,and the resultant catalyst delivered considerable ORR performance in a seawater electrolyte,with a high half-wave potential(E_(1/2))of 0.868 V and a good maximum power density(Pmax)of 182 mW·cm^(−2)in the assembled SZABs,much higher than those of the Pt/C catalyst(E_(1/2):0.846 V;Pmax:150 mW·cm^(−2)).The in-situ characterization and theoretical calculations revealed that the Fe sites have a higher Cl^(−)adsorption affinity than the Co sites,and preferentially adsorbs Cl^(−)in a seawater electrolyte during the ORR process,and thus constructs a low-concentration Cl^(−)local microenvironment through the common-ion exclusion effect,which prevents Cl^(−)adsorption and corrosion in the Co active centers,achieving impressive catalytic stability.In addition,the directional charge movement between Fe and Co atomic pairs establishes a local electric field,optimizing the adsorption energy of Co sites for oxygen-containing intermediates,and further improving the ORR activity. 展开更多
关键词 Seawater zinc-air battery Oxygen reduction reaction Local electric field Chloride ion fixation strategy Sin-gle-atom catalyst
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Genomic insights into the absence of root nodule formation and nitrogen fixation in Zenia insignis
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作者 Hang Yu Yongbin Lu +4 位作者 Chao Zhang Wenyuan Yang Hongjiang Xie Huiru Liu Haifeng Wang 《Journal of Genetics and Genomics》 2025年第6期860-863,共4页
Symbiotic nitrogen fixation in members of the Fabaceae family is highly efficient and beneficial for global agriculture,but not all species in this family form root nodules with rhizobial bacteria.Nodulation mainly oc... Symbiotic nitrogen fixation in members of the Fabaceae family is highly efficient and beneficial for global agriculture,but not all species in this family form root nodules with rhizobial bacteria.Nodulation mainly occurs in plants belonging to the Papilionoideae and Caesalpinioideae subfamilies(Tederso0 et al.,2018;van Velzen et al.,2019).Nodulation mechanisms in Fabaceae are well studied(Yang et al.,2022),and genomic comparisons of nodulating and non-nodulating host species can provide valuable insights into the evolutionary and genetic basis of this key process. 展开更多
关键词 nitrogen fixation genomic insights rhizobial bacterianodulation symbiotic nitrogen fixation root nodule formation Zenia insignis genomic comparisons FABACEAE
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Insights of stearic acid/polypyrrole superhydrophobic coating on controlling corrosion,antibacterial and cytocompatibility of biodegradable Mg alloy and its implication on fracture fixation
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作者 Satyabrata Nigamananda Sahoo Pritish Rath +4 位作者 Santanu Mandal Meeta Ashok Kamde Partha Saha Samit Kumar Nandi Mangal Roy 《Journal of Magnesium and Alloys》 2025年第12期6195-6220,共26页
Surface modification is found to be an effective way to control the initial degradation of Mg based biomedical alloys.The present study focuses on the modulation of in vitro and in vivo degradation behavior of Mg-Ce a... Surface modification is found to be an effective way to control the initial degradation of Mg based biomedical alloys.The present study focuses on the modulation of in vitro and in vivo degradation behavior of Mg-Ce alloy through a stearic acid-treated polypyrrole coating,which developed superhydrophobic surface(contact angle∼153°)that drastically enhanced the corrosion resistance(more than 85%efficacy).Cerium addition to Mg alloy results basal texture strengthening and grain refinement,resulting in improved mechanical properties.All the specimens exhibited excellent antibacterial performance against gram-negative E.Coli(DH5α)and gram positive S.aureus bacteria.The oligodynamic effect of polypyrrole coating leads to complete bacterial mitigation.Non-toxic nature of the specimens was studied by MC3T3-E1 cell proliferation and differentiation in indirect cell culture method.Improved corrosion resistance of the coated specimen leads to enhanced cell proliferation and osteogenic differentiation.Hard tissue histology and micro-CT analysis exhibited higher fraction of newly formed callus tissues and highest bone-implant integration across the coated specimen,when implanted in rabbit femur.Efficacy of the material in fracture healing was evaluated by implanting bone plate and screw in a clinically fractured goat tibia.At 3 months,complete fracture healed with no vital organ toxicity was observed for the coated specimen.The present results suggest that Ce addition and polypyrrole coating are effective ways to modulate the corrosion and biocompatibility behavior making it a potential candidate for fracture fixation applications. 展开更多
关键词 POLYPYRROLE Superhydrophobic coating ANTIBACTERIAL CYTOCOMPATIBILITY Fracture fixation
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Heterogeneous iron-based catalysts for a sustainable photoinduced nitrogen fixation
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作者 Amalia M.Grigoras Federica Valentini +1 位作者 Loredana Latterini Luigi Vaccaro 《Green Energy & Environment》 2025年第4期733-755,共23页
Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also par... Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also paralleleds by the high CO_(2) emissions associated with its production.Therefore,decarbonizing NH3 synthesis is one of the most urgent contemporary challenges.Taking inspiration from Nature,solar-driven nitrogen fixation under mild conditions is one of the most promising yet challenging alternatives to classic methods.In this review,we focused our attention on the photocatalytic methods for the synthesis of ammonia;in particular,we concentrated on stable and recyclable heterogeneous Fe-based photocatalysts for producing NH3.Indeed,recoverable and widely abundant and low-cost iron catalysts may represent a very promising tool for future sustainable access to this largely desired chemical target.After an overview of the pioneering works on Fe-driven nitrogen photofixation,the recent strategies on the use of Fe are herein reported.Compared with pristine photocatalysts,adding Fe as dopant or composite and heterojunction highly enhances the photocatalytic performances,opening the way to sustainable and low-cost nitrogen production. 展开更多
关键词 Nitrogen fixation AMMONIA Iron photocatalysts PHOTOCATALYSIS
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How Fear Memory is Updated:From Reconsolidation to Extinction?
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作者 Jiahui Chen Zhuowen Fang +2 位作者 Xiaolan Zhang Yanrong Zheng Zhong Chen 《Neuroscience Bulletin》 2025年第6期1054-1084,共31页
Post-traumatic stress disorder(PTSD)is a psychiatric disorder caused by traumatic past experiences,rooted in the neurocircuits of fear memory formation.Memory processes include encoding,storing,and recalling to forget... Post-traumatic stress disorder(PTSD)is a psychiatric disorder caused by traumatic past experiences,rooted in the neurocircuits of fear memory formation.Memory processes include encoding,storing,and recalling to forgetting,suggesting the potential to erase fear memories through timely interventions.Conventional strategies such as medications or electroconvulsive therapy often fail to provide permanent relief and come with significant side-effects.This review explores how fear memory may be erased,particularly focusing on the mnemonic phases of reconsolidation and extinction.Reconsolidation strengthens memory,while extinction weakens it.Interfering with memory reconsolidation could diminish the fear response.Alternatively,the extinction of acquired memory could reduce the fear memory response.This review summarizes experimental animal models of PTSD,examines the nature and epidemiology of reconsolidation to extinction,and discusses current behavioral therapy aimed at transforming fear memories to treat PTSD.In sum,understanding how fear memory updates holds significant promise for PTSD treatment. 展开更多
关键词 Post-traumatic stress disorder Fear memory RECONSOLIDATION extinction Engram
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Cerium-based metal-organic framework-modified natural mineral vermiculite for photocatalytic nitrogen fixation under visible-light irradiation
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作者 Sixiao Liu Tianyi Wang +2 位作者 Lei Zhang Chengyin Wang Huan Pang 《Chinese Chemical Letters》 2025年第3期177-181,共5页
In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal... In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal-organic framework,Ce-UiO-66.Vermiculite was treated with formic acid;thus,Ce-UiO-66 particles grew in-situ on vermiculite;then,Ce-UiO-66 particles were activated by ultraviolet irradiation.The vermiculite absorbed visible light with a narrow band gap,and transferred photogenerated electrons to the active sites on Ce-UiO-66.Moreover,the lamella structure of vermiculite protected Ce-UiO-66 during photocatalytic process.Therefore,with only 45.92 wt%of Ce-UiO-66,the nitrogen fixation performance of VMCeact was 2.29 times that of pure activated Ce-UiO-66 particles under 455nm light irradiation(apparent quantum efficiency of 4.49%),and retained at least 96.05%performance after 7×24 h of photocatalytic reaction.This cost-reduced,efficient and stable photocatalyst has the opportunity to facilitate environmentally friendly ammonia production. 展开更多
关键词 Metal-organic frameworks VERMICULITE Nitrogen fixation VISIBLE-LIGHT LOW-COST
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Elevated extinction risk of low-elevation populations of two songbirds on the Taiwan island
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作者 Xuntao Ma Yadan Liu +2 位作者 Zhang Zhang Mingwang Zhang Feng Dong 《Avian Research》 2025年第3期467-472,共6页
Prevailing concerns on mountainous biodiversity are concentrated on the impacts of climate change at higher elevations. However, the lower elevations are facing additional human disturbance and are expected to suffer ... Prevailing concerns on mountainous biodiversity are concentrated on the impacts of climate change at higher elevations. However, the lower elevations are facing additional human disturbance and are expected to suffer from higher extinction risk but have attracted less conservation attention. Here, we employed population genomics to compare extinction risk two common songbirds—the Vinous-throated Parrotbill (Sinosuthora webbiana) and the Rufous-capped Babbler (Cyanoderma ruficeps)—at lower and higher elevations on the Taiwan island. As the result, we observed decreased genetic diversity and increased genetic load and thus elevated extinction risk in the low-elevation populations of both birds in the eastern slope of the Central Mountains on the Taiwan island. In contrast, genetic-load patterns of both birds in the western slope might be confused by substantial gene flow across lower and higher elevations. These results, on the one hand, call for conservation efforts to lower elevations in mountains and, on the other hand, highlight the importance of population connection in maintaining population viability under impending global change. 展开更多
关键词 extinction risk Genetic load Human disturbance Mountainous biodiversityi Population genomics
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Clinical Efficacy of Different Internal Fixation Implants for Post-Traumatic Nonunion of Limb Fractures:A Comparative Study
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作者 Li He Cheng Weiqiang Zhu Dingguo 《Science International Innovative Medicine》 2025年第2期25-30,共6页
To compare the clinical efficacy of locking plate(LP)fixation and intramedullary nail(IMN)fixation for the treatment of post-traumatic nonunion of diaphyseal fractures of the femur and tibia.Methods:This single-center... To compare the clinical efficacy of locking plate(LP)fixation and intramedullary nail(IMN)fixation for the treatment of post-traumatic nonunion of diaphyseal fractures of the femur and tibia.Methods:This single-center retrospective comparative study included 50 adult patients with aseptic nonunion of femoral or tibial diaphyseal fractures treated at our institution between January 2015 and January 2025.Patients underwent either locking-plate(LP)fixation(n=25)or intramedullary nailing(IMN)(n=25).The primary outcome was radiographic union at 12 months postoperatively.Secondary outcomes included time to union,operative time,intraoperative blood loss,length of hospital stay,incidence of complications(superficial/deep infection,implant failure,malunion),and 12-month functional status assessed by the Lower Extremity Functional Scale(LEFS).Statistical comparisons used Welch t tests for continuous variables and χ^(2) or Fisher exact tests for categorical variables.The protocol received institutional review board approval with waiver of informed consent.Results:Among 50 patients(LP=25;IMN=25),the 12-month union rate was 88.00%(22/25)in the LP group and 96.00%(24/25)in the IMN group(p=0.609).Time to union was shorter with IMN(6.20±1.83 vs 7.51±2.12 months;p=0.023).Operative time(110.52±25.23 vs 145.81±30.21 min;p<0.01)and intraoperative blood loss(250.41±80.64 vs 350.22±95.30 ml;p<0.01)favored IMN.Length of hospital stay was similar(6.24±1.83 vs 6.82±2.11 days;p=0.284).The incidence of superficial wound infection did not differ significantly(12.00%vs 4.00%;p=0.609).Twelve-month LEFS scores were comparable(65.44±10.21 vs 67.10±9.83;p=0.451).Conclusion:Both locking plate and intramedullary nail fixation are effective in the treatment of femoral and tibial nonunion,with high rates of union and good functional outcomes.Intramedullary nailing may be associated with a shorter time to union,reduced operative time and blood loss,and a lower risk of superficial wound infection compared to locking plate fixation.The choice of implant should be individualized based on fracture characteristics,patient factors,and surgeon preference. 展开更多
关键词 NONUNION Limb Fractures Internal fixation Locking Plate Intramedullary Nail Clinical Efficacy
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Extinction and Optimal Control of Stochastic Epidemic Model with Multiple Vaccinations and Time Delay
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作者 YANG Rujie QIU Hong JU Xuewei 《数学理论与应用》 2025年第2期110-121,共12页
In this paper,based on the SVIQR model we develop a stochastic epidemic model with multiple vaccinations and time delay.Firstly,we prove the existence and uniqueness of the global positive solution of the model,and co... In this paper,based on the SVIQR model we develop a stochastic epidemic model with multiple vaccinations and time delay.Firstly,we prove the existence and uniqueness of the global positive solution of the model,and construct suitable functions to obtain sufficient conditions for disease extinction.Secondly,in order to effectively control the spread of the disease,appropriate control strategies are formulated by using optimal control theory.Finally,the results are verified by numerical simulation. 展开更多
关键词 Stochastic epidemic model Multiple vaccinations extinction of disease Isolation delay Optimal control
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