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Chinese Journal of Chemistry 2018年第1期36卷 55-58页

作者： Yang Gu Changhui Lu Yucheng gu Qilong Shen Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic Chemistry University of Chinese Academy Sciences Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China Syngenta Jealott's Hill International Research Cente Bracknell Berkshire RG42 6EY UK

Highly regiodivergent copper-catalyzed allylic/propargylic difluoromethylation reactions by employing different ligands are described. When 5,6-dimethyl-1,10-phenanthroline was used as the ligand, exclusively α-difluoromethylated products were obtained, while γ-selective difluoromethylated products were generated when N-heterocyclic carbene-SIPr was used as the ligand. Likewise, high α- vs. γ-selectivities were achieved in the presence of similar copper catalysts for the reactions of propargyl bromides. Moreover, a copper-catalyzed asymmetric allylic difluoromethylation reaction with moderate to good enantioselectivity by the use of chiral ligands was developed.

关键词： fluorine difluoromethyl copper asymmetric allylic substitution

Formate as a supplementary substrate facilitates sugar metabolism and solvent production by Clostridium beijerinckii NCIMB 8052

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Synthetic and Systems Biotechnology 2023年第2期8卷 196-205页

作者： Ran Zhao Wenyue Dong Chen yang Weihong Jiang Jinzhong Tian Yang Gu CAS-Key Laboratory of Synthetic Biology CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China University of Chinese Academy of Sciences Beijing100049China

Microbial utilization and conversion of organic one-carbon compounds,such as formate and methanol that can be easily produced from CO_(2),has emerged as an attractive approach for biorefinery.In this study,we discovered Clostridium beijerinckii NCIMB 8052,a typical solventogenic Clostridium strain,to be a native formate-utilizing bacterium.^(13)C isotope analysis showed that formate could be metabolized via both assimilation and dissimi-lation pathways in C.beijerinckii NCIMB 8052.Notably,the use of formate as the supplementary substrate by this strain could significantly enhance its glucose consumption and ABE(acetone-butanol-ethanol)production,largely due to the up-regulation of genes responsible for glycolysis and glucose transport under formate stress.Based on these findings,we further improved formate tolerance of C.beijerinckii NCIMB 8052 by adaptive lab-oratory evolution,generating an evolved strain Cbei-FA01.The Cbei-FA01 strain could produce 23.0 g/L of ABE solvents using glucose and formate as dual substrates,~50%higher than that of the wild-type strain under the same condition.Moreover,such a promotion effect of formate on ABE production by Cbei-FA01 was also observed in fermenting a glucose-xylose mixture.This work reveals a previously unreported role of formate in biological ABE production,providing a new approach to utilize this one-carbon source.

关键词： Formate utilization Clostridium beijerinckii Metabolic pathways Adaptive laboratory evolution ABE solvents

Molecular design for enhanced spin transport in molecular semiconductors

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Nano Research 2023年第12期16卷 13457-13473页

作者： Tingting yang yang Qin Xianrong gu Xiangnan Sun Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Material Science and Engineering Zhengzhou UniversityZhengzhou 450001China

Molecular semiconductors(MSCs),characterized by a longer spin lifetime than most of other materials due to their weak spin relaxation mechanisms,especially at room temperature,together with their abundant chemical tailorability and flexibility,are regarded as promising candidates for spintronic applications.Molecular spintronics,as an emerging subject that utilizes the unique properties of MSCs to study spin-dependent phenomena and properties,has attracted wide attention.In molecular spintronic devices,MSCs play the role as medium for information transport,process,and storage,in which the efficient spin inject–transport process is the prerequisite.Herein,we focus mainly on summarizing and discussing the recent advances in theoretical principles towards spin transport of MSCs in terms of the injection of spin-polarized carriers through the ferromagnetic metal/MSC interface and the subsequent transport within the MSC layer.Based on the theoretical progress,we cautiously present targeted design strategies of MSCs that contribute to the optimization of spin-transport efficiency and give favorable approaches to exploring accessional possibilities of spintronic materials.Finally,challenges and prospects regarding current spin transport are also presented,aiming to promote the development and application of the rosy and energetic field of molecular spintronics.

关键词： molecular spintronics molecular semiconductors spin transport spin injection molecular design

The p-orbital magnetic topological states on a square lattice

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National Science Review 2022年第4期9卷 84-91页

作者： Jing-yang You Bo gu Gang Su Kavli Institute for Theoretical Sciences and CAS Center for Excellence in Topological Quantum ComputationUniversity of Chinese Academy of Sciences Department of Physics Faculty of ScienceNational University of Singapore Physical Science Laboratory Huairou National Comprehensive Science Center School of Physical Sciences University of Chinese Academy of Sciences

Honeycomb or triangular lattices were extensively studied and thought to be proper platforms for realizing the quantum anomalous Hall effect(QAHE), where magnetism is usually caused by d orbitals of transition metals. Here we propose that a square lattice can host three magnetic topological states, including the fully spin-polarized nodal loop semimetal, QAHE and the topologically trivial ferromagnetic semiconductor, in terms of the symmetry and k · p model analyses that are material independent. A phase diagram is presented. We further show that the above three magnetic topological states can indeed be implemented in the two-dimensional(2 D) materials Sc Li Cl5, Li Sc Z5(Z=Cl, Br) and Sc Li Br5, respectively.The ferromagnetism in these 2 D materials is microscopically revealed from p electrons of halogen atoms. This present study opens a door to explore the exotic topological states as well as quantum magnetism from p-orbital electrons by means of the material-independent approach.

关键词： p-orbital magnetism square lattice topological states

Numerical Simulation of the Distribution Function and Free Energy of a Single Wormlike Polymer Confined between Hard Walls

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Chinese Journal of Polymer Science 2020年第2期38卷 179-186,I0007页

作者： Yang Gu Hui Zhang Dong-Liang Zhang School of Mathematics Sciences Beijing Normal UniversityBeijing 100875China Laboratory of Mathematics and Complex Systems Ministry of EducationSchool of Mathematics SciencesBeijing Normal UniversityBeijing 100875China The department of Orthodontics Beijing Stomatology Hospital Affiliated to Capital Medical UniversityBeijing 100006China

We focus on the distribution and free energy of a wormlike polymer confined between two parallel hard walls.The variation in the distribution and free energy of the wormlike chain as the spacing between the walls decreases(or as the total contour length of the wormlike chain increases or as the persistence length of the chain increases)is simulated.The main reason for these changes is a degradation of the long wormlike chain into a Gaussian long chain under weak confinement.

关键词： Wormlike polymer Free energy Weak confinement

Identification of ring current proton precipitation driven by scattering of electromagnetic ion cyclotron waves

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Fundamental Research 2023年第2期3卷 257-264页

作者： Binbin Ni yang Zhang Xudong gu Department of Space Physics School of Electronic InformationWuhan UniversityWuhanHubei 430072China CAS Center for Excellence in Comparative Planetology Hefei 230026China MNR Key Laboratory for Polar Science Polar Research Institute of ChinaShanghai 200136China

Among the most intense emissions in the Earth's magnetosphere,electromagnetic ion cyclotron(EMIC)waves are regarded as a critical candidate contributing to the precipitation losses of ring current protons,which however lacks direct multi-point observations to establish the underlying physical connection.Based upon a robust conjunction between the satellite pair of Van Allen Probe B and NOAA-19,we perform a detailed analysis to capture simultaneous enhancements of EMIC waves and ring current proton precipitation.By assuming that the ring current proton precipitation is mainly caused by EMIC wave scattering,we establish a physical model between the wave-driven proton diffusion and the ratio of precipitated-to-trapped proton count rates,which is subsequently applied to infer the intensity of EMIC waves required to cause the observed proton precipitation.Our simulations indicate that the model results of EMIC wave intensity,obtained using either the observed or empirical Gaussian wave frequency spectrum,are consistent with the wave observations,within a factor of 1.5.Our study therefore strongly supports the dominant contribution of EMIC waves to the ring current proton precipitation,and offers a valuable means to construct the global profile of EMIC wave intensity using low-altitude NOAA POES proton measurements,which generally have a broad L-shell coverage and high time resolution in favor of near-real-time conversion of the global EMIC wave distribution.

关键词： Electromagnetic ion cyclotron waves Ring current protons Wave-particle interactions Conjugate observations Precipitation losses

Comparison of brain functions between healthy participants and methamphetamine users with various addiction histories:Data analysis based on EEG and fNIRS

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Journal of Innovative Optical Health Sciences 2024年第3期17卷 41-55页

作者： Xuelin gu Xiaoou Li Banghua yang College of Medical Instruments Shanghai University of Medicine&Health SciencesShanghai 201318P.R.China School of Mechanical and Electrical Engineering and Automation Shanghai UniversityShanghai 200444P.R.China

The electroencephalogram(EEG)rhythm and functional near-infrared spectroscopy(fNIRS)activation levels have not been compared between a healthy control group(HCG)and methamphetamine user group(MUG)with different addiction histories.This study used 64-electrode EEG and fNIRS to conduct an experiment that analyzed the resting and craving states.The EEG and fNIRS data of 56 participants were collected,including 14 healthy participants,14 methamphetamine users with an addiction history of 0.5–5 years,14 users with an addiction history of 5–10 years,and 14 users with an addiction history of 10–15 years.Isolated effective coherence(iCoh)within the brain network was used to process the EEG data.Statistical analysis was performed to compare differences in iCoh among the delta,theta,alpha,beta,and gamma bands and explore oxyhemoglobin activation levels in the ventrolateral prefrontal cortex,dorsolateral prefrontal cortex,orbitofrontal cortex,and frontopolar prefrontal cortex(FPC)of the control group.Finally,the Kmeans,Gaussian mixed model(GMM),linear discriminant analysis(LDA),support vector machine(SVM),Bayes,and convolutional neural networks(CNN)algorithms were used to classify methamphetamine users based on drug and neutral images.A 3-class accuracy was achieved.Changes in EEG and fNIRS activation levels of HCG and MUG with varied addiction histories were demonstrated.

关键词： Drug addiction history electroencephalogram functional near-infrared spectroscopy isolated effective coherence addiction history classification

Layered Structural PBAT Composite Foams for Efficient Electromagnetic Interference Shielding

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Nano-Micro Letters 2024年第2期16卷 273-286页

作者： Jianming yang Hu Wang Yali Zhang Hexin Zhang Junwei gu School of Chemistry and Chemical Engineering Anhui University of TechnologyMa’anshanAnhui 243032People’s Republic of China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072ShaanxiPeople’s Republic of China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuPeople’s Republic of China

The utilization of eco-friendly,lightweight,high-efficiency and high-absorbing electromagnetic interference(EMI)shielding composites is imperative in light of the worldwide promotion of sustainable manufacturing.In this work,magnetic poly(butyleneadipate-coterephthalate)(PBAT)microspheres were firstly synthesized via phase separation method,then PBAT composite foams with layered structure was constructed through the supercritical carbon dioxide foaming and scraping techniques.The merits of integrating ferroferric oxideloaded multi-walled carbon nanotubes(Fe3O4@MWCNTs)nanoparticles,a microcellular framework,and a highly conductive silver layer have been judiciously orchestrated within this distinctive layered configuration.Microwaves are consumed throughout the process of“absorption-reflection-reabsorption”as much as possible,which greatly declines the secondary radiation pollution.The biodegradable PBAT composite foams achieved an EMI shielding effectiveness of up to 68 dB and an absorptivity of 77%,and authenticated favorable stabilization after the tape adhesion experiment.

关键词： Electromagnetic interference shielding Layered structure Supercritical carbon dioxide foaming Poly(butyleneadipateco-terephthalate) Microcellular

Label-free quantitative proteomics analysis models in vivo and in vitro reveal key proteins and potential roles in sciatic nerve injury

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生物细胞(英文) 2023年第9期47卷 2069-2080页

作者： Yang Gu MINGguANG BI DEHUI CHEN NING NI JIANMING CHEN Department of Trauma Orthopedics Surgery Ningbo No.6 HospitalNingbo University School of MedicineNingbo315000China Department of Orthopedics Ningbo Medical CenterLihuili HospitalNingbo University School of MedicineNingbo315000China Department of Orthopedic Surgery Fujian Medical University Union HospitalFuzhou350001China School of Medicine Ningbo UniversityNingbo315000China

Background:The underlying mechanism of sciatic nerve injury(SNI)is a common motor functional disorder,necessitates further research.Methods:A rat model of SNI was established,with the injury group subjected to compressive injury of the right sciatic nerve exposed at the midpoint of the thigh and the sham surgery group undergoing the same surgical procedure.An oxygen-glucose deprivation model was employed to simulate in vitro SNI in PC12 cells.Following data acquisition and quality control,differentially expressed proteins(DEPs)in each model were identified through differential analysis,and enrichment analysis was used to explore the potential functions and pathways of the DEPs.Venn diagrams were drawn,and DEPs from both in vivo and in vitro SNI models were imported into the STRING database to construct a protein-protein interaction network and screen for hub proteins.Results:After the peptide segments obtained from rat nerve blockade and PC12 cells met quality requirements,258 DEPs were identified in rat nerve samples,and 119 DEPs were screened in PC12 cells.Enrichment analysis revealed that DEPs in the rat model were predominantly concentrated in biological functions such as myogenic cell proliferation and signaling related to lipid and energy metabolism.DEPs in the in vitro model were mainly enriched in biological processes such as phagocytosis and were associated with lipid transport and metabolism.Two hub proteins,amyloid precursor protein(APP)and fibronectin 1(FN1),were identified through MCC,MCODE,and Degree scoring.Both PC12 cells and external validation sets showed relatively higher expression of APP and FN1 in injured samples.Results of gene set enrichment analysis indicated that these two proteins were associated with metabolic pathways,such as biosynthesis of glycosaminoglycan chondroitin sulfate and biosynthesis of unsaturated fatty acids.Conclusion:APP and FN1 are potential key molecules involved in SNI and are associated with various metabolic pathways in nerve repair.These findings provide a theore

关键词： Oxygen glucose deprivation Proteomics Sciatic nerve injury Peripheral nerve injury

Pneumatic separation system for collected seedlings using subdivided air streams

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International Journal of Agricultural and Biological Engineering 2022年第2期15卷 84-92页

作者： Delong Jiang Song gu Qi Chu Yanli yang Meizhang gu Yi yang College of Engineering South China Agricultural UniversityGuangzhou 510642China College of Electronic Engineering South China Agricultural UniversityGuangzhou 510642China Key Laboratory of Key Technology on Agricultural Machine and Equipment Ministry of EducationSouth China Agricultural UniversityGuangzhou 510642China guangzhou Sky Mechanical&Electrical Technology Co.Ltd Guangzhou 510642China

To adhere to the needs of automated supply of collected seedlings for mechanized grafting and cutting machines for enhancing their operational efficiency,herein,a separation system that uses subdivided air streams to separate the collected seedlings is developed.The separation system comprises a feeder for supplying collected seedlings,a seedling separator that uses subdivided air streams,a picking belt for the separated seedlings,a delivery unit for the separated seedlings,a pneumatic unit,and a control unit.To investigate the complete performance of separation,picking,and delivery of the separation system,several separation experiments were conducted to separate the collected Anthurium seedlings.The results show that the consistency of the moving direction of seedlings floated by subdivided air streams in the separation container and the moving direction of the picking belt have a significant effect on the picking of the separated seedlings by the picking belt.Moreover,the seedling supply timing of the feeder has a significant effect on the stability of the collected seedling separation rate during continuous separation.When this timing is such that the percentage of separated seedlings is 70%,the separation rate of continuous separation operation is 2.24 plant/s(the separation productivity is 8060 plants/h)with 0.12 CV.The operating conditions are 0.5 MPa separation pressure,0.5 s nozzle operation time,and 60 mm seedling thickness in the separation container.Moreover,the staying times of the collected seedlings separated in the separation container are less than 2.5 min.

关键词： grafting cuttings pneumatic separation system continuous separation subdivided air stream separation speed