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Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第1期68卷 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-cheng Tang Ding-Kang chen ming-ming Cao Yao-Wen Chang Hong-yu Tang Chun-Mao yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

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Blood lead levels among children aged 0 to 6 years in 16 cities of China, 2004-2008

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Chinese Medical Journal 2013年第12期126卷 2291-2295页

作者： XIE Xiao-hua TAN Zang-wen JIA Ni FAN Zhao-yang ZHANG Shuai-ming Lu Yan-yu chen Li DAI Yao-hua Department of Integrated Early Childhood Development Capital Institute of Paediatrics Beijing 100020 China

Background The adverse health effects of lead for children under 6 years are well *** to assess the lead exposure among children in China are small in sample size and lack of national representative *** aim of this study therefore was to describe blood lead levels and identify risk factors for lead exposure among children aged 0 to 6 years living in 16 cities in *** We analyzed data from blood lead levels surveillance in China carried out in 16 large cities between 2004 and 2008.A stratified clustered random sampling strategy was used.A total of 69 968 children aged 0 to 6 years were *** conducted multiple Logistic regression analyses to explore risk factors to high blood lead *** The geometric mean blood lead level of the children was 4.50 μg/dl （median：4.90 μg/dl; IQR：3.20-7.00 μg/dl）.Overall prevalence of blood lead level ≥10.00 μg/dl among 0-to 6-year-old children was 7.57%.But the proportion of blood lead level ≥5.00 but 〈10.00 μg/dl was 42.12%.Blood lead levels were significantly higher in boys （4.63 μg/dl） than in girls （4.35 μg/dl）（P 〈0.0001）.The geometric mean blood lead levels and prevalence of blood lead level ≥10.00 μg/dl increased with age （P 〈0.0001 for the two trends）.After controlling for sociodemographic,dietary and behavior factors,multivariable analysis indicated that lower maternal education,male gender,younger age,often biting pencil or/and toys,walking or playing for long time on the street,not washing hands before eating are major risk factors for higher lead *** The blood lead levels among Chinese children in urban areas are lower than previous studies but close to those of developed ***,children with low lead exposure account for almost half and the sociodemographic factors （age,male sex,and low mother education level） continue to be associated with higher blood lead levels.

关键词： children lead poisoning blood lead risk factors

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Ammonia Volatilization and Deriitrification Losses from an Irrigated Maize-Wheat Rotation Field in the North China Plain

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Pedosphere 2004年第4期14卷 533-540页

作者： ZHANGyu-ming chenDe-Li ZHANGJia-Bao R.EDIS HUChun-Sheng ZHUAn-Ning InstituteofGeneticsandDevelopmentalBiology ChineseAcademyofSciencesShijiazhuang050021（China） DepartmentofResourceManagementandHorticulture InstituteofLandandFoodResourcetheUniversityofMel-bourneParkville3052Victoria（Australia） InstituteofSoilScience ChineseAcademyofSciencesNanjing210008（China）

Ammonia (NH3) volatilization, denitrification loss, and nitrous oxide (N2O) emission were investigated from an irrigated wheat-maize rotation field on the North China Plain, and the magnitude of gaseous N loss from denitrification and NH3 volatilization was assessed. The micrometeorological gradient diffusion method in conjunction with a Bowen Ratio system was utilized to measure actual NH3 fluxes over a large area, while the acetylene inhibition technique (intact soil cores) was employed for measurement of denitrification losses and N2O emissions. Ammonia volatilization loss was 26.62% of the applied fertilizer nitrogen (N) under maize, while 0.90% and 15.55% were lost from the wheat field at sowing and topdressing, respectively. The differences in NH3 volatilization between different measurement events may be due to differences between the fertilization methods, and to differences in climatic conditions such as soil *** losses in the fertilized plots were 0.67%-2.87% and 0.31%-0.49% of the applied fertilizer N under maize and wheat after subtracting those of the controls, respectively. Nitrous oxide emissions in the fertilized plots were approximately 0.08%-0.41% and 0.26%-0.34% of the applied fertilizer N over the maize and wheat seasons after subtracting those of the controls, correspondingly. The fertilizer N losses due to NH3 volatilization were markedly higher than those through denitrification and nitrous oxide emissions. These results indicated that NH3 volatilization was an important N transformation in the crop-soil system and was likely to be the major cause of low efficiencies with N fertilizer in the study area. Denitrification was not a very important pathway of N fertilizer loss, but did result in important evolution of the greenhouse gas N2O and the effect of N2O emitted from agricultural fields on environment should not be overlooked.

关键词： ammonia volatilization denitrification gaseous N loss N_2O emission

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MXene Hybridized Polymer with Enhanced Electromagnetic Energy Harvest for Sensitized Microwave Actuation and Self‑Powered Motion Sensing

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Nano-Micro Letters 2025年第3期17卷 265-279页

作者： yu‑Ze Wang yu‑Chang Wang Ting‑Ting Liu Quan‑Liang Zhao chen‑Sha Li Mao‑Sheng Cao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China School of Materials Science and Engineering Peking UniversityBeijing 100871People’s Republic of China School of Mechanical and Material Engineering North China University of TechnologyBeijing 100144People’s Republic of China Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080People’s Republic of China

Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.

关键词： Microwave absorption Electromagnetic response Energy harvest Self-sensing Soft actuator

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Homologous CoS2 interface with directed electron transfer and strong chloridion repulsion for efficient seawater oxidation

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Science China Chemistry 2025年

作者： yuan Tian Jiang-Bo chen Jie Ying Ge Tian yu-Xuan Xiao Yi Lu Si-ming Wu Wei Geng Ling Shen Xiao-yu Yang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing and School of Materials Science and Engineering and Shenzhen Research Institute & Laoshan Laboratory Wuhan University of Technology School of Chemical Engineering and Technology Sun Yat-Sen University National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies Foshan Xianhu Laboratory

Seawater electrolysis is a highly promising method to produce high energy density hydrogen,especially in dry areas that have scarce freshwater ***,application of seawater electrolysis is confronted by two major problems associated with catalysts employed for the anodic oxygen evolution reaction （OER） including the competitive hypochlorite evolution reaction（HCER） and strong chloridion （Cl–） triggered *** studies aimed at overcoming these problems,a facile method has been developed to synthesize a homologous CoS2heterojunction as an OER *** to a difference in work functions at the interface and increased electron density,this material has directed electron transfer and strong chloridion repulsion properties,*** have shown that CoS2achieves low overpotentials of 289 and 322 mV at 10 mA cm-2current density in respective alkaline （1 M KOH） and alkaline simulated seawater ***,the outstanding stability of CoS2is reflected in a negligible decline in activity during promotion of the OER for 100 *** of density functional theory calculations reveal that the homologous CoS2heterojunction promotes directed electron transport for optimizing adsorption/desorption of reactive species and heightens the Cl-adsorption energy for strongly repulsing Cl-,phenomena that enhance OER performance in alkaline simulated seawater.

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一种GNSS/SINS容错深组合导航系统设计

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中国惯性技术学报 2017年第1期25卷 77-80页

作者：陈帅蒋长辉付梦印薄煜明赵琛屈新芬南京理工大学自动化学院南京210094 中国工程物理研究院电子工程研究所绵阳621000

卫星惯性深组合导航技术是卫星惯性组合导航领域最有前景的技术之一。深组合导航系统的关键技术之一就是矢量跟踪环路技术,当一个或者多个通道信号质量较差时,组合导航滤波器必然会受影响,从而会影响矢量跟踪环路的参数计算,因此通道运... 详细信息

卫星惯性深组合导航技术是卫星惯性组合导航领域最有前景的技术之一。深组合导航系统的关键技术之一就是矢量跟踪环路技术,当一个或者多个通道信号质量较差时,组合导航滤波器必然会受影响,从而会影响矢量跟踪环路的参数计算,因此通道运行状态的实时检测十分必要。针对此问题,为每个通道设计了新的通道子滤波器和对应的子滤波器状态检测函数,当通道存在故障时,能够及时检测出故障并对故障通道进行隔离;当通道恢复正常时,也能够及时检测到并充分利用恢复正常的通道卫星信号。仿真结果表明,在部分通道卫星信号被遮挡导致伪距异常的环境下,改进的矢量跟踪环路提高了矢量跟踪卫星惯性深组合的导航性能,有效遏制了故障通道对组合导航系统的影响。

关键词：深组合容错状态检测矢量跟踪

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Adhesive cryogel particles for bridging confined and irregular tissue defects

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Military Medical Research 2023年第6期10卷 763-777页

作者： Yao-Ting Xue ming-yu chen Jia-Sheng Cao Lei Wang Jia-Hao Hu Si-Yang Li Ji-Liang Shen Xin-Ge Li Kai-Hang Zhang Shu-Qiang Hao Sarun Juengpanich Si-Bo cheng Tuck-Whye Wong Xu-Xu Yang Tie-Feng Li Xiu-Jun Cai Wei Yang Department of Engineering Mechanics Zhejiang UniversityHang‑zhou 310027China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang UniversityHangzhou 310027China Center for X‑Mechanics Department of Engineering MechanicsZhejiang Univer‑sityHangzhou 310027China Department of General Surgery Sir Run-Run Shaw HospitalZhejiang UniversityHangzhou 310016China Soft Intelligent Materials Co. LtdSuzhou 215123China School of Biomedical Engineering and Health Sciences and Advanced Membrane Technology Research Centre Universiti Teknologi Malaysia81310 SkudaiMalaysia

Background Reconstruction of damaged tissues requires both surface hemostasis and tissue *** with damage resulting from physical trauma or surgical treatments may have arbitrary surface topographies,making tissue bridging *** This study proposes a tissue adhesive in the form of adhesive cryogel particles(ACPs) made from chitosan,acrylic acid,1-ethyl-3-(3-dimethylaminopropyl) carbodiimide(EDC) and N-hydroxysuccinimide(NHS).The adhesion performance was examined by the 180-degree peel test to a collection of tissues including porcine heart,intestine,liver,muscle,and *** of ACPs was evaluated by cell proliferation of human normal liver cells(LO2)and human intestinal epithelial cells(Caco-2).The degree of inflammation and biodegradability were examined in dorsal subcutaneous rat *** ability of ACPs to bridge irregular tissue defects was assessed using porcine heart,liver,and kidney as the ex vivo ***,a model of repairing liver rupture in rats and an intestinal anastomosis in rabbits were established to verify the effectiveness,biocompatibility,and applicability in clinical *** ACPs are applicable to confined and irregular tissue defects,such as deep herringbone grooves in the parenchyma organs and annular sections in the cavernous *** formed tough adhesion between tissues[(670.9±50.1) J/m^(2) for the heart,(607.6±30.0) J/m^(2) for the intestine,(473.7±37.0) J/m^(2) for the liver,(186.1±13.3) J/m^(2) for the muscle,and(579.3±32.3) J/m^(2) for the stomach].ACPs showed considerable cytocompatibility in vitro study,with a high level of cell viability for 3 d[(98.8±1.2)%for LO2 and(98.3±1.6)%for Caco-2].It has comparable inflammation repair in a ruptured rat liver(P=0.58 compared with suture closure),the same with intestinal anastomosis in rabbits(P=0.40 compared with suture anastomosis).Additionally,ACP-based intestinal anastomosis(less than 30 s) was remarkably faster than the convention

关键词： Tissue reconstruction Wet adhesion Adhesive hydrogel Bioadhesive

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Co/Co_(7)Fe_(3)heterostructures with controllable alloying degree on carbon spheres as bifunctional electrocatalyst forrechargeable zinc-air batteries

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 476-487页

作者： Junkang chen Yongyue Zhuang Yanxin Qiao yu Zhang Aihua yuan Hu Zhou School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying *** optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline *** intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co *** the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based *** particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending *** work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.

关键词： bifunctional electrocatalysts oxygen reduction reaction oxygen evolution reaction zinc-air battery metal/alloy carbon sphere

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Robust facial expression recognition via lightweight reinforcement learning for rehabilitation robotics

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Optoelectronics Letters 2025年第2期21卷 97-104页

作者： chen Yifan FAN Weiming GAO Hongwei yu Jiahui JU Zhaojie School of Computing University of Portsmouth School of Automation and Electrical Engineering Shenyang Ligong University Department of Biomedical Engineering Zhejiang University

This paper proposes a lightweight reinforcement network (LRN) and auxiliary label distribution learning (ALDL)based robust facial expression recognition (FER) *** designed representation reinforcement (RR) network mainly comprises two modules,i.e.,the RR module and the auxiliary label space construction (ALSC) *** RR module highlights key feature messaging nodes in feature maps,and ALSC allows multiple labels with different intensities to be linked to one ***,LRN has a more robust feature extraction capability when model parameters are greatly reduced,and ALDL is proposed to contribute to the training effect of LRN in the condition of ambiguous training *** tested our method on FER-Plus and RAF-DB datasets,and the experiment demonstrates the feasibility of our method in practice during rehabilitation robots.

关键词： Reinforcement learning

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A Novel Self-Supervised Learning Network for Binocular Disparity Estimation

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 209-229页

作者： Jiawei Tian yu Zhou Xiaobing chen Salman A.AlQahtani Hongrong chen Bo Yang Siyu Lu Wenfeng Zheng Department of Computer Science and Engineering Major in Bio Artificial IntelligenceHanyang UniversityAnsan-si15577Republic of Korea School of Electrical and Computer Engineering Louisiana State UniversityBaton RougeLA 70803USA Department of Computer Engineering College of Computer and Information SciencesKing Saud UniversityRiyadh11574Saudi Arabia School of Automation University of Electronic Science and Technology of ChinaChengdu610054China

Two-dimensional endoscopic images are susceptible to interferences such as specular reflections and monotonous texture illumination,hindering accurate three-dimensional lesion reconstruction by surgical *** study proposes a novel end-to-end disparity estimation model to address these *** approach combines a Pseudo-Siamese neural network architecture with pyramid dilated convolutions,integrating multi-scale image information to enhance robustness against lighting *** study introduces a Pseudo-Siamese structure-based disparity regression model that simplifies left-right image comparison,improving accuracy and *** model was evaluated using a dataset of stereo endoscopic videos captured by the Da Vinci surgical robot,comprising simulated silicone heart sequences and real heart video *** results demonstrate significant improvement in the network’s resistance to lighting interference without substantially increasing ***,the model exhibited faster convergence during training,contributing to overall performance *** study advances endoscopic image processing accuracy and has potential implications for surgical robot applications in complex environments.

关键词： Parallax estimation parallax regression model self-supervised learning Pseudo-Siamese neural network pyramid dilated convolution binocular disparity estimation

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