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Construction of lightweight NiCo-LDH/carbon fiber nanocomposites for broad-band microwave absorption

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ChemPhysMater

ChemPhysMater 2024年第2期3卷 212-219页

作者： Shuangshuang Liu Zhengying Shen Beibei zhao nannan Wu School of Material Science and Engineering Shandong University of Science and TechnologyQingdao 266590China

The rapidly increasing usage of electric technology during the last decades has facilitated the fabrication of high-efficiency microwave absorption(MA)materials(MAMs).In this study,hierarchical NiCo layered double hydroxide(LDH)/carbon fiber(CF)nanocomposites were constructed via simple hydrothermal production,and their MA properties were evaluated.Benefiting from interfacial polarization,defect-induced polarization,and multiple reflections induced by the hierarchical sheets,the LDH/CF composites delivered a better MA perfor-mance than that by pure CF and LDH.The addition ratio of the LDH also played a vital role in determining the impedance matching and microwave absorption performance.Specifically,the optimized LDH/CF composites demonstrated an exceptional reflection loss(RL)of-62.47 dB with a thickness of 2.22 mm,and an effective absorption bandwidth(EAB)covering 6.4 GHz(11.6-18.0 GHz)at a 20 wt.%filling ratio,which outperformed the reported CF-based microwave absorbers.Owing to this superior MA,the as-prepared LDH/CF composites demonstrated to be significantly promising for advancing the usage of CF-based MAMs.

关键词： Microwave absorption Nickel cobalt layered double hydroxides Carbon fiber Interface polarization

Short telomeres impede germ cell specification by upregulating MAPK and TGFβsignaling

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Science China(Life Sciences) 2023年第2期66卷 324-339页

作者： Chenglei Tian Dai Heng nannan zhao Linlin Liu Xiaoyan Sheng Jiyu Chen &Lin Liu State Key Laboratory of Medicinal Chemical Biology Nankai UniversityTianjin 300350China Haihe Laboratory of Cell Ecosystem Chinese Academy of Medical Sciences&Peking Union Medical CollegeTianjin 300020China Frontiers Science Center for Cell Responses College of Life SciencesNankai UniversityTianjin 300071China Institute of Translational Medicine Tianjin Union Medical CenterNankai UniversityTianjin 300000China The Danish Stem Cell Center University of CopenhagenBlegdamsvej 3BDK-2200 Copenhagen NDenmark

Functional telomeres protect chromosome ends and play important roles in stem cell maintenance and differentiation. Short telomeres negatively impact germ cell development and can contribute to age-associated infertility. Moreover, telomere syndrome resulting from mutations of telomerase or telomere-associated genes exhibits short telomeres and reduced fertility. It remains elusive whether and how telomere lengths affect germ cell specification. We report that functional telomere is required for the coordinated germ cell and somatic cell fate decisions. Using telomerase gene Terc deficient mice as a model, we show that short telomeres restrain germ cell specification of epiblast cells but promote differentiation towards somatic lineage. Short telomeres increase chromatin accessibility to elevate TGFβ and MAPK/ERK signaling for somatic cell differentiation. Notably,elevated Fst expression in TGFβ pathway represses the BMP4-pSmad signaling pathway, thus reducing germ cell formation. Reelongation of telomeres by targeted knock-in of Terc restores normal chromatin accessibility to suppress TGFβ and MAPK signaling, thereby facilitating germ cell formation. Taken together, our data reveal that functional telomeres are required for germ cell specification by repressing TGFβ and MAPK signaling.

关键词： telomere primordial germ cell MAPK TGFβ chromatin accessibility

The light and hypoxia induced gene ZmPORB1 determines tocopherol content in the maize kernel

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Science China(Life Sciences) 2024年第3期67卷 435-448页

作者： nannan Liu Yuanhao Du Shijuan Yan Wei Chen Min Deng Shutu Xu Hong Wang Wei Zhan Wenjie Huang Yan Yin Xiaohong Yang Qiao zhao Alisdair R.Fernie Jianbing Yan National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural UniversityWuhan 430070China Hubei Hongshan Laboratory Wuhan 430070China Agro-biological Gene Research Center Guangdong Academy of Agricultural SciencesGuangzhou 510640China College of Agronomy Hunan Agricultural UniversityChangsha 410128China College of Agronomy Northwest A&F UniversityXi'an 710000China State Key Laboratory of North China Crop Improvement and Regulation Hebei Sub-center of National Maize Improvement Center of ChinaCollege of AgronomyHebei Agricultural UniversityBaoding 071001China College of Life Sciences South-Central Minzu UniversityWuhan 430070China Plant Science Facility of the Institute of Botany Chinese Academy of SciencesBeijing 100093China National Maize Improvement Center of China Beijing Key Laboratory of Crop Genetic ImprovementChina Agricultural UniversityBeijing 100093China Shenzhen Key Laboratory of Synthetic Genomics Guangdong Provincial Key Laboratory of Synthetic GenomicsShenzhen Institute of Synthetic BiologyShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Max Planck Institute of Molecular Plant Physiology Potsdam-Golm 14476Germany

Tocopherol is an important lipid-soluble antioxidant beneficial for both human health and plant growth. Here, we fine mapped a major QTLqVE1 affecting γ-tocopherol content in maize kernel, positionally cloned and confirmed the underlying gene ZmPORB1(por1), as a protochlorophyllide oxidoreductase. A 13.7 kb insertion reduced the tocopherol and chlorophyll content, and the photosynthetic activity by repressing ZmPORB1 expression in embryos of NIL-K22, but did not affect the levels of the tocopherol precursors HGA(homogentisic acid)and PMP(phytyl monophosphate). Furthermore, ZmPORB1 is inducible by low oxygen and light, thereby involved in the hypoxia response in developing embryos. Concurrent with natural hypoxia in embryos, the redox state has been changed with NO increasing and H_(2)O_(2) decreasing, which lowered γ-tocopherol content via scavenging reactive nitrogen species. In conclusion, we proposed that the lower lightharvesting chlorophyll content weakened embryo photosynthesis, leading to fewer oxygen supplies and consequently diverse hypoxic responses including an elevated γ-tocopherol consumption. Our findings shed light on the mechanism for fine-tuning endogenous oxygen concentration in the maize embryo through a novel feedback pathway involving the light and low oxygen regulation of ZmPORB1 expression and chlorophyll content.

关键词： maize tocopherol hypoxia photosynthesis ZmPORB1

Characteristics of gut microbiota determine effects of specific probiotics strains in patients with functional constipation

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Chinese Medical Journal 2024年第1期137卷 120-122页

作者： Haohao Zhang Lijuan Sun Zhixin zhao Yao Zhou Yuyao Liu nannan Zhang Junya Yan Shibo Wang Renlong Li Jing Zhang Xueying Wang Wenjiao Li Yan Pan Meixia Wang Bing Luo Mengbin Li Zhihong Sun Yongxiang zhao Yongzhan Nie State Key Laboratory of Targeting Oncology National Center for International Research of Bio-targeting TheranosticsGuangxi Key Laboratory of Bio-targeting TheranosticsCollaborative Innovation Center for Targeting Tumor Diagnosis and TherapyGuangxi Talent Highland of Bio-targeting TheranosticsGuangxi Medical UniversityNanningGuangxi 530021China State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and National Clinical Research Center for Digestive Diseases Xijing Hospital of Digestive DiseasesFourth Military Medical UniversityXi’anShaanxi 710032China Key Laboratory of Resource Biology and Biotechnology in Western China Ministry of EducationSchool of MedicineNorthwest UniversityXi’anShaanxi 710000China Key Laboratory of Dairy Biotechnology and Engineering Ministry of EducationKey Laboratory of Dairy Products ProcessingMinistry of Agriculture and Rural AffairsInner Mongolia Key Laboratory of Dairy Biotechnology and EngineeringInner Mongolia Agricultural UniversityHohhotInner Mongolia 010018China

To the Editor:Probiotics are a promising treatment modality for functional constipation(FC);however,the factors affecting individual responses to probiotics remain unclear.Growing evidence has identified that there is a strong relationship among the gut microbiota and constipation and related gut-brain axis.[1]The gut microbiota may modulate the gut functions via gut metabolites or trigger the release of gut hormones,such as peptide YY,gastric inhibitory polypeptide,and 5-hydroxytryptamine.[2]In turn,gut hormones affect gut secretion,motility,and sensation through their receptors located on epithelial,enteric,and smooth muscle cells.[2]Based on these findings,exogenous probiotics have been used in patients with constipation;however,few have produced consistent results.[3]In this study,we investigated the efficacy and safety of several specific probiotics strains for constipation,and also examined the potential reasons for the individualized effects of probiotics,which may facilitate interventional decisionmaking for FC patients.

关键词： constipation patients sensation

Dynamics of iron and aluminum storages in a subtropical forest headwater stream

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Journal of Mountain Science 2024年第7期21卷 2193-2205页

作者： YI Qiumeng MA Diting PENG Yan zhao Zemin YUAN Chaoxiang YUAN Ji NI Xiangyin WU Fuzhong YUE Kai AN nannan Key Laboratory of Humid Subtropical Eco-geographical Processes of Ministry of Education School of Geographical SciencesFujian Normal UniversityFuzhou 350117China Fujian Sanming Forest Ecosystem National Observation and Research Station Sanming 365002China

The forest headwater streams are important hubs for connecting terrestrial and aquatic ecosystems,with plant litter and sediments as the major carriers for material migrations;however,until now we knew little about the dynamics of trace elements such as iron(Fe)and aluminum(Al)in forest headwater streams.Here,we quantitatively identified the spatiotemporal dynamics of Fe and Al storages in plant litter and sediments and their influencing factors in a subtropical forest headwater stream,and assessed the potential pollution risk.The results showed that:(1)the mean concentrations of Fe and Al in plant litter(sediments)were 5.48 and 8.46(7.39 and 47.47)g·kg^(-1),and the mean storages of Fe and Al in plant litter(sediments)were 0.26 and 0.43(749.04 and 5030.90)g·m^(-2),respectively;(2)the storages of Fe and Al in plant litter and sediments significantly fluctuated from January to December,and showed a decreasing pattern from the source to mouth;and(3)storages of Fe and Al had no significant correlation with riparian forest type and the present of tributary and the Fe and Al storages in plant litter were mainly affected by water temperature and water alkalinity,and their storages in sediments were mainly affected by water temperature and frequency of rainfall;and(4)there were no anthropogenic pollution in Fe and Al in the forest headwater stream.Our study revealed the primary factors of concentrations and storages of Fe and Al in plant litter and sediments in a forest headwater stream,which will improve our understanding of the role of headwater streams in forest nutrient storage and cycling along with hydrological processes.

关键词： Plant litter Sediments Storage Forest headwater stream Stream characteristics Trace element

“冲突—共识”:城市更新规划的公众利益实现路径——基于恩宁路二期和碧江社区实证

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城市规划 2024年第4期48卷 51-58页

作者：赵楠楠华南理工大学公共管理学院香港大学城市规划与设计系中国

新时期城市更新规划亟需加强对多元行动主体交往导向的公众利益认知。基于对不同尺度“公众”内涵的辨析,本文认为公众利益是“共同体”集体交往的结果,以广州恩宁路二期改造项目和佛山顺德碧江社区微更新项目为例,深入论证基于“冲突... 详细信息

新时期城市更新规划亟需加强对多元行动主体交往导向的公众利益认知。基于对不同尺度“公众”内涵的辨析,本文认为公众利益是“共同体”集体交往的结果,以广州恩宁路二期改造项目和佛山顺德碧江社区微更新项目为例,深入论证基于“冲突—共识”视角的异质化公众利益实现路径、规划模式和社区行动。研究发现,恩宁路案例表现出“冲突化解”导向下的协商型规划模式,采取“化整为零”的方式,在冲突释放的过程中“自上而下”地建构公众利益。碧江案例表现出“共识建构”导向下的协作型规划模式,采取“提零为整”的方式,在寻求共识的过程中“自下而上”地建构公众利益。最后,提出提升规划策略灵活性、强化政府主体制度化作用、规范社区规划师体系等政策建议,为我国推进社区参与下的微更新规划实践提供实证参考。

关键词：城市更新社区治理公众利益参与式规划社区规划师地方知识

Network pharmacology and molecular docking identify mechanisms of medicinal plant-derived 1,2,3,4,6-penta-O-galloyl-beta-D-glucose treating gastric cancer

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BIOCELL 2023年第5期47卷 977-989页

作者： MAN REN YUAN YANG DAN LI nannan zhao YUPING WANG YONGNING ZHOU The First Clinical Medical College Lanzhou UniversityLanzhou730000China Gansu Key Laboratory of Gastroenterology Lanzhou UniversityLanzhou730000China Department of Geriatrics Gerontology The First Hospital of Lanzhou UniversityLanzhou730000China Office of National Drug Clinical Trial Institutions The First Hospital of Lanzhou UniversityLanzhou730000China School of Pharmacy Lanzhou UniversityLanzhou730000China Department of Gastroenterology The First Hospital of Lanzhou UniversityLanzhou730000China

Background:1,2,3,4,6-penta-O-galloyl-beta-D-glucose(PGG)is a natural polyphenolic compound derived from multiple medicinal plants with favorable anticancer activity.Methods:In this study,the mechanisms of PGG against gastric cancer were explored through network pharmacology and molecular docking.First,the targets of PGG were searched in the Herbal Ingredients’Targets(HIT),Similarity Ensemble Approach(SEA),and Super-PRED databases.The potential targets related to gastric cancer were predicted from the Human Gene Database(GeneCards)and DisGeNET databases.The intersecting targets of PGG and gastric cancer were obtained by Venn diagram and then subjected to protein-protein interaction analysis to screen hub targets.Functional and pathway enrichment of hub targets were analyzed through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway databases.The differential expression and survival analysis of hub targets in gastric cancer were performed based on The Cancer Genome Atlas database.Finally,the affinity of PGG with hub targets was visualized by molecular docking.Results:Three hub targets were screened,including mitogen-activated protein kinase 14(MAPK14),BCL2 like 1(BCL2L1),and vascular endothelial growth factor A(VEGFA).MAPK14 had a higher expression,while BCL2L1 and VEGFA had lower expression in gastric cancer than in normal conditions.Enrichment analysis indicated enrichment of these hub targets in MAPK,neurotrophin,programmed death-ligand 1(PD-L1)checkpoint,phosphatidylinositol 3-kinases/protein kinase B(PI3K-Akt),Ras,and hypoxia-inducible factor-1(HIF-1)signaling pathways.Conclusion:Therefore,network pharmacology and molecular docking analyses revealed that PGG exerts a therapeutic efficacy on gastric cancer by multiple targets(MAPK14,BCL2L1,and VEGFA)and pathways(MAPK,PD-L1 checkpoint,PI3K-Akt,Ras,and HIF-1 pathways).

关键词： 1,2,3,4,6-penta-O-galloyl-beta-D-glucose Gastric cancer Network pharmacology Molecular docking MAPK14 BCL2L1 VEGFA

Utilization of Changyun Jujube, a Cultivar with Resistance to Witches Broom Disease

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Plant Diseases and Pests 2024年第3期15卷 23-25,30页

作者： Ya LIU nannan SUN Li zhao Jiayun LIU Xiumei GAO Shanting District Fruit Industry Service Center Zaozhuang 277200China Zaozhuang Agricultural Machinery Technology Extension Center Zaozhuang 277100China Zaozhuang Forestry Development Service Center Zaozhuang 277100China

In 2021,the Shanting District Fruit Industry Service Center conducted an application test of a treatment for jujube witches broom disease using Changyun jujube.The results demonstrated that when diseased Changhong jujube plants were grafted with Changyun jujube in the spring using bark or cleft grafting,the majority of the new shoots of Changyun jujube exhibited no symptoms of witches broom disease,while a few exhibited symptoms of the disease.With the growth of new shoots,the symptoms of witches broom disease gradually abated,returning to normal growth and development.Similarly,the symptoms of witches broom disease on the rootstock below the grafting mouth also gradually abated,returning to normal.The Changyun jujube rootstock was utilized as the intermediate rootstock to grafting the jujube cultivars Qiyuexian and Fucuimi.The two cultivars were subsequently affixed with branch bark from the witches broom disease.The two cultivars did not exhibit any symptoms of witches broom disease,thus providing an opportunity to investigate potential treatments for this disease in jujube.Finally,the cultivation techniques of the Changyun jujube were presented.

关键词： Changyun Jujube Resistance to witches broom disease Crispy jujube

A Novel Flux-weakening Control Method with Quadrature Voltage Constrain for Electrolytic Capacitorless PMSM Drives

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CES Transactions on Electrical Machines and Systems 2022年第3期6卷 279-287页

作者： Junya Huo Dawei Ding Zekun Ren Gaolin Wang nannan zhao Lianghong Zhu Dianguo Xu the School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150001China the Guangdong Midea Air-Conditioning Equipment Co. Ltd.Foshan 528311China IEEE

In electrolytic capacitorless permanent magnet synchronous motor(PMSM) drives, the DC-link voltage will fluctuate in a wide range due to the use of slim film capacitor. When the flux-weakening current is lower than-ψf/Ld during the high speed operation, the flux-weakening control loop will transform to a positive feedback mode, which means the reduction of flux-weakening current will lead to the acceleration of the voltage saturation, thus the whole system will be unstable. In order to solve this issue, this paper proposes a novel flux-weakening method for electrolytic capacitorless motor drives to maintain a negative feedback characteristic of the control loop during high speed operation. Based on the analysis of the instability mechanism in flux-weakening region, a quadrature voltage constrain mechanism is constructed to stabilize the system.Meanwhile, the parameters of the controller are theoretically designed for easier industrial application. The proposed algorithm is implemented on a 1.5 kW electrolytic capacitorless PMSM drive to verify the effectiveness of the flux-weakening performance.

关键词： Permanent magnet synchronous motor(PMSM) Electrolytic capacitorless drive Flux-weakening control Voltage constrain Stable operation