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Synergistic asymmetric diarylation of tethered alkenes via C–H functionalization of simple(hetero)arenes

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Science China Chemistry 2024年第8期67卷 2710-2718页

作者： jian Yao Can zhao Lili Shao Xiaohong Huo Xiaoming Wang Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in Chemical Synthesis Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

By virtue of the atom-and step-economy, utilization of simple arenes as a supplant of pre-prepared aryl metal species or aryl halides for the synthesis of arylated chiral molecules has attracted great attention from the synthetic community. While transition-metal-catalyzed enantioselective diarylation of tethered alkenes has been employed to prepare important chiral cyclic compounds, the direct use of simple arenes as aryl precursors is still underdeveloped, probably due to the difficulties in the effective control of the reactivity, site-selectivity and/or enantioselectivity. Herein we report an asymmetric Pd/Ag dual metal catalytic system for the non-directed, site-and enantioselective domino Heck/intermolecular C–H functionalization of *** studies showed that Pd and Ag act in cooperation in the catalysis and the chiral bisphosphine ligand plays a bifunctional role, i.e., assisting the silver species in the cleavage of the aryl C–H bond, while inducing the enantioselectivity on direct complexation with palladium. This method provides an efficient approach to the corresponding chiral oxindoles with good enantiomeric excesses from a broad scope of arenes, including fluoroarenes, heteroarenes and several complex products derived from medicines or natural products.

关键词： asymmetric Pd/Ag dual metal catalytic system simple arenes C–H functionalization bifunctional role chiral oxindoles

Leader-follower Optimal Selection Method for Distributed Control System in Active Distribution Networks

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 314-323页

作者： jian Le Liangang zhao Cao Wang Qian Zhou Yang Wang School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China

Aiming at the shortcomings of a traditional centralized control in an active distribution network(AND),this paper proposes a leader-follower distributed group cooperative control strategy to realize multiple operation and control tasks for an *** distributed information exchange protocols of the distributed generation(DG)group devoted to node voltage regulation or exchange power control are developed using a DG power utilization ratio as the consensus *** these bases,this study further investigates the leader optimal selection method for a DG group to improve the response speed of the distributed control ***,a single or multiple leader selection model is established to minimize the constraints of the one-step convergence factor and the number of leaders to improve the response speed of the distributed control *** simulation results of the IEEE 33 bus standard test system show the effectiveness of the proposed distributed control *** addition,the response speed of a DG control group can be improved effectively when the single or multiple leaders are selected optimally.

关键词： Active distribution1network consensus algorithm leader-follower system mixed-integer semidefinite programming optimal distributed control

An aptamer-driven DNA nanodevice for improved delivery of synthetic immunostimulants

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Nano Research 2024年第10期17卷 9078-9083页

作者： Dejie Lu Zhenghan Di Lele Li jian zhao Li Zheng Guangxi Engineering Center in Biomedical Materials for Tissue and Organ Regeneration Collaborative Innovation Centre of Regenerative Medicine and Medical BioResource Development and ApplicationGuangxi Key Laboratory of Regenerative MedicineThe First Affiliated Hospital of Guangxi Medical UniversityGuangxi Medical UniversityNanning 530021China CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and TechnologyBeijing 100190China

Efficient delivery of therapeutics to immune cells remains a formidable challenge for cancer *** this work,we demonstrate that an aptamer-driven DNA nanodevice,constructed through linkage of a synthetic immunostimulant(Toll-like receptor 9 agonist:CpG motif)to an aptamer,could significantly enhance the immunostimulatory activity by facilitating the uptake and retention of therapeutics in *** administration of the DNA nanodevice results in efficient tumor growth inhibition in both breast cancer and melanoma mouse *** studies suggest that the DNA nanodevice leads to reeducation of tumor-associated macrophages and ultimately to reversing the tumor immune *** strategy for aptamer-mediated and vehicle-free delivery of immunostimulatory oligonucleotides provides a potential platform for cancer immunotherapy.

关键词： aptamer immunostimulatory oligonucleotides DNA nanodevice tumor-associated macrophages cancer therapy

A Recursive DRL-Based Resource Allocation Method for Multibeam Satellite Communication Systems

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Chinese Journal of Electronics 2024年第5期33卷 1286-1295页

作者： haowei MENG Ning XIN hao QIN Di zhao State Key Laboratory of Integrated Services Networks Xidian University China Academy of Space Technology Institute of Telecommunication Satellite

Optimization-based radio resource management(RRM) has shown significant performance gains on high-throughput satellites(HTSs). However, as the number of allocable on-board resources increases, traditional RRM is difficult to apply in real satellite systems due to its intense computational complexity. Deep reinforcement learning(DRL) is a promising solution for the resource allocation problem due to its model-free advantages. Nevertheless, the action space faced by DRL increases exponentially with the increase of communication scale, which leads to an excessive exploration cost of the algorithm. In this paper, we propose a recursive frequency resource allocation algorithm based on long-short term memory(LSTM) and proximal policy optimization(PPO), called PPO-RA-LOOP,where RA means resource allocation and LOOP means the algorithm outputs actions in a recursive manner. Specifically, the PPO algorithm uses LSTM network to recursively generate sub-actions about frequency resource allocation for each beam, which significantly cuts down the action space. In addition, the LSTM-based recursive architecture allows PPO to better allocate the next frequency resource by using the generated sub-actions information as a prior knowledge, which reduces the complexity of the neural network. The simulation results show that PPO-RA-LOOP achieved higher spectral efficiency and system satisfaction compared with other frequency allocation algorithms.

关键词： High-throughput satellites Proximal policy optimization Deep reinforcement learning Long-short term memory High-throughput satellites Proximal policy optimization Deep reinforcement learning Long-short term memory OPTIMIZATION POWER

Enhancing single-cell encapsulation in droplet microfluidics with fine-tunable on-chip sample enrichment

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Microsystems & Nanoengineering 2024年第1期10卷 149-160页

作者： Tao Tang hao zhao Shaofei Shen Like Yang Chwee Teck Lim Department of Biomedical Engineering National University of Singapore117583 SingaporeSingapore Integrative Sciences and Engineering Programme NUS Graduate SchoolNational University of Singapore119077 SingaporeSingapore Shanxi Key Lab for Modernization of TCVM College of Life ScienceShanxi Agricultural UniversityTaiguShanxi 030801China Institute for Health Innovation&Technology National University of Singapore117599 SingaporeSingapore Mechanobiology Institute National University of Singapore117411 SingaporeSingapore Institute for Digital Molecular Analytics and Science Nanyang Technological University636921 SingaporeSingapore

Single-cell encapsulation in droplet microfluidics is commonly hindered by the tradeoff between cell suspension density and on-chip focusing *** this study,we introduce a novel droplet microfluidic chip to overcome this *** chip comprises a double spiral focusing unit,a flow resistance-based sample enrichment module with fine-tunable outlets,and a crossflow droplet generation *** a low-density cell/bead suspension(2×10^(6) objects/mL),cells/beads are focused into a near-equidistant linear arrangement within the double spiral *** excess water phase is diverted while cells/beads remain focused and sequentially encapsulated in individual *** performance was assessed through numerical simulations and experiments at three flow rates(40,60,80μL/min),demonstrating successful focusing at 40 and 80μL/min for beads and cells,*** addition,both simulation and experimental results revealed that the flow resistance at the sample enrichment module is adjustable by punching different outlets,allowing over 50%of the aqueous phase to be ***8n-based droplet detection algorithms realized the counting of cells/beads in droplets,statistically demonstrating single-cell and bead encapsulation rates of 72.2%and 79.2%,*** the results indicate that this on-chip sample enrichment approach can be further developed and employed as a critical component in single-cell encapsulation in water-in-oil droplets.

关键词： beads outlet sample

Circulating RNA ZFR promotes hepatocellular carcinoma cell proliferation and epithelial-mesenchymal transition process through miR-624-3p/WEE1 axis

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Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 52-63页

作者： Li Zhang Sai He hao Guan Yao zhao Di Zhang Department of General Surgery the Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710004China Department of Breast Cancer Shaanxi Provincial Cancer HospitalXi’an 710000China

Background:Hepatocellular carcinoma(HCC),the most common type of primary liver cancer,is the fourth leading cause of cancer-related deaths *** evidence shows that the expression of circulating RNA ZFR(circZFR)is upregulated in HCC ***,the molecular mechanism of circZFR in HCC is ***:Quantitative reverse transcriptase polymerase chain reaction(qRT-PCR)was employed to detect the expression of circZFR,microRNA-624-3p(miR-624-3p)and WEE1 in HCC tissues and *** R assay and actinomycin D treatment assay were used to analyze the characteristics of *** functional analysis,the capacities of colony formation,cell proliferation,cell apoptosis,migration and invasion were assessed by colony formation assay,5-ethynyl-2-deoxyuridine(EdU)assay,flow cytometry assay and transwell *** blot was used to examine the protein levels of WEE1 and epithelial-mesenchymal transition(EMT)-related *** interactions between miR-624-3p and circZFR or WEE1 were validated by dual-luciferase reporter assay and RNA immunoprecipitation(RIP)*** models were established to determine the role of circZFR in ***:circZFR and WEE1 were upregulated,while miR-624-3p expression was reduced in HCC tissues and *** could sponge miR-624-3p,and WEE1 was a downstream gene of *** of circZFR significantly reduced the malignant behaviors of HCC and that co-transfection with miR624-3p inhibitor restored this *** of WEE1 abolished the inhibitory effect of miR624-3p mimic on HCC ***,circZFR acted as a competitive endogenous RNA(ceRNA)to regulate WEE1 expression by targeting ***,in vivo studies have illustrated that circZFR knockdown inhibited tumor ***:circZFR knockdown reduced HCC cell proliferation,migration and invasion and promoted apoptosis by regulating the miR-624-3p/WEE1 axis,suggesting that the circZFR/miR-624-3p/WEE1 axis might

关键词： Hepatocellular carcinoma circZFR miR-624-3p WEE1 Liver cancer

Interplay between mesenchymal stem cells and macrophages:Promoting bone tissue repair

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World Journal of Stem Cells 2024年第4期16卷 375-388页

作者： Fei-Fan Zhang Yang hao Kuai-Xiang Zhang jiang-Jia Yang Zhi-Qiang zhao Hong-jian Liu Ji-Tian Li Molecular Biology Lab Henan Luoyang Orthopedic Hospital(Henan Provincial Orthopedic Hospital)Zhengzhou 450000Henan ProvinceChina Graduate School Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina Graduate School Henan University of Chinese MedicineZhengzhou 450046Henan ProvinceChina Department of Orthopaedics The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina

The repair of bone tissue damage is a complex process that is well-orchestrated in time and space,a focus and difficulty in orthopedic *** recent years,the success of mesenchymal stem cells(MSCs)-mediated bone repair in clinical trials of large-area bone defects and bone necrosis has made it a candidate in bone tissue repair engineering and regenerative *** are closely related to *** one hand,MSCs regulate the immune regulatory function by influencing macrophages proliferation,infiltration,and phenotype polarization,while also affecting the osteoclasts differentiation of *** the other hand,macrophages activate MSCs and mediate the multilineage differentiation of MSCs by regulating the immune *** cross-talk between MSCs and macrophages plays a crucial role in regulating the immune system and in promoting tissue *** full use of the relationship between MSCs and macrophages will enhance the efficacy of MSCs therapy in bone tissue repair,and will also provide a reference for further application of MSCs in other diseases.

关键词： Bone tissue damage Inflammation Macrophages Mesenchymal stem cells Tissue regeneration

Genome-wide association study of grain micronutrient concentrations in bread wheat

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Journal of Integrative Agriculture 2024年第5期23卷 1468-1480页

作者： Yongchao hao Fanmei Kong Lili Wang Yu zhao Mengyao Li Naixiu Che Shuang Li Min Wang Ming hao Xiaocun Zhang Yan zhao State Key Laboratory of Crop Biology/College of Agronomy Shandong Agricultural UniversityTai'an 271018China College of Resources and Environment Shandong Agricultural UniversityTai'an 271018China Jining Liangshan Ecological Environment Affairs Center Jining 272100China College of Forestry Shandong Agricultural UniversityTai'an 271018China

Bread wheat(Triticum aestivum)is a staple food crop *** genetic dissection of important nutrient traits is essential for the biofortification of wheat to meet the nutritional needs of the world's growing ***,45,298 single-nucleotide polymorphisms(SNPs)from 55K chip arrays were used to genotype a panel of 768 wheat cultivars,and a total of 154 quantitative trait loci(QTLs)were detected for eight traits under three environments by genome-wide association study(GWAS).Three QTLs(qMn-3B.1,qFe-3B.4,and qSe-3B.1/qFe-3B.6)detected repeatedly under different environments or traits were subjected to subsequent analyses based on linkage disequilibrium decay and the P-values of significant *** SNPs in the three QTL regions formed six haplotypes for qMn-3B.1,three haplotypes for qFe-3B.4,and three haplotypes for qSe-3B.1/*** analysis revealed significant differences among *** results indicated that the concentrations of several nutrient elements have been modified during the domestication of landraces to modern *** on the QTL regions,we identified 15 high-confidence genes,eight of which were stably expressed in different tissues and/or developmental ***3B02G046100 in qMn-3B.1 and TraesCS3B02G199500 in qSe-3B.1/qFe-3B.6 were both inferred to interact with metal ions according to the Gene Ontology(GO)***3B02G199000,which belongs to qSe-3B.1/qFe-3B.6,was determined to be a member of the WRKY gene ***,this study provides several reliable QTLs that may significantly affect the concentrations of nutrient elements in wheat grain,and this information will facilitate the breeding of wheat cultivars with improved grain properties.

关键词： bread wheat nutritional element GWAS domestication haplotype

Resource Allocation in Multi-User Cellular Networks:A Transformer-Based Deep Reinforcement Learning Approach

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China Communications 2024年第5期21卷 77-96页

作者： zhao Di Zheng Zhong Qin Pengfei Qin hao Song Bin State Key Laboratory of Integrated Services Networks Xidian University710071China China Academy of Space Technology Beijing 100081China

To meet the communication services with diverse requirements,dynamic resource allocation has shown increasing *** this paper,we consider the multi-slot and multi-user resource allocation(MSMU-RA)in a downlink cellular scenario with the aim of maximizing system spectral efficiency while guaranteeing user *** first model the MSMURA problem as a dual-sequence decision-making process,and then solve it by a novel Transformerbased deep reinforcement learning(TDRL)***,the proposed TDRL approach can be achieved based on two aspects:1)To adapt to the dynamic wireless environment,the proximal policy optimization(PPO)algorithm is used to optimize the multi-slot RA strategy.2)To avoid co-channel interference,the Transformer-based PPO algorithm is presented to obtain the optimal multi-user RA scheme by exploring the mapping between user sequence and resource *** results show that:i)the proposed approach outperforms both the traditional and DRL methods in spectral efficiency and user fairness,ii)the proposed algorithm is superior to DRL approaches in terms of convergence speed and generalization performance.

关键词： dynamic resource allocation multi-user cellular network spectrum efficiency user fairness