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Advances of Electrochemical and Electrochemiluminescent Sensors Based on Covalent Organic Frameworks

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Nano-Micro Letters 2024年第2期16卷 395-422页

作者： Yue Cao Ru Wu yan‑yan Gao yang Zhou Jun‑Jie Zhu Key Laboratory for Organic Electronics and Information Displays(KLOEID)and Institute of Advanced Materials(IAM) Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023People’s Republic of China State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023People’s Republic of China

Covalent organic frameworks(COFs),a rapidly developing category of crystalline conjugated organic polymers,possess highly ordered structures,large specific surface areas,stable chemical properties,and tunable pore microenvironments.Since the first report of boroxine/boronate ester-linked COFs in 2005,COFs have rapidly gained popularity,showing important application prospects in various fields,such as sensing,catalysis,separation,and energy storage.Among them,COFs-based electrochemical(EC)sensors with upgraded analytical performance are arousing extensive interest.In this review,therefore,we summarize the basic properties and the general synthesis methods of COFs used in the field of electroanalytical chemistry,with special emphasis on their usages in the fabrication of chemical sensors,ions sensors,immunosensors,and aptasensors.Notably,the emerged COFs in the electrochemiluminescence(ECL)realm are thoroughly covered along with their preliminary applications.Additionally,final conclusions on state-of-the-art COFs are provided in terms of EC and ECL sensors,as well as challenges and prospects for extending and improving the research and applications of COFs in electroanalytical chemistry.

关键词： Covalent organic frameworks Electrochemistry Electrochemiluminescence Sensors

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Exosome-encapsulated lncRNA HOTAIRM1 contributes to PM_(2.5)-aggravated COPD airway remodeling by enhancing myofibroblast differentiation

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Science China(Life Sciences) 2024年第5期67卷 970-985页

作者： Huaqi Guo Luo Fei Hengyi Yu yan Li yan Feng Shaowei Wu yan Wang The Ninth People’s Hospital of Shanghai Jiao Tong University School of Medicine Shanghai 200011China School of Public Health Shanghai Jiao Tong University School of MedicineShanghai 200020China Department of Occupational and Environmental Health Sciences School of Public HealthXi’an Jiao Tong University Health Science CenterXi’an 710049China

Emphysema,myofibroblast accumulation and airway remodeling can occur in the lungs due to exposure to atmospheric pollution,especially fine particulate matter(PM_(2.5)),leading to chronic obstructive pulmonary disease(COPD).Specifically,bronchial epithelium-fibroblast communication participates in airway remodeling,which results in COPD.An increasing number of studies are now being conducted on the role of exosome-mediated cell-cell communication in disease pathogenesis.Here,we investigated whether exosomes generated from bronchial epithelial cells could deliver information to normal stromal fibroblasts and provoke cellular responses,resulting in airway obstruction in COPD.We studied the mechanism of exosome-mediated intercellular communication between human bronchial epithelial(HBE) cells and primary lung fibroblasts(pLFs).We found that PM_(2.5)-induced HBE-derived exosomes promoted myofibroblast differentiation in pLFs.Then,the exosomal lncRNA expression profiles derived from PM_(2.5)-treated HBE cells and nontreated HBE cells were investigated using an Agilent Human LncRNA Array.Combining coculture assays and direct exosome treatment,we found that HBE cell-derived exosomal HOTAIRM1 facilitated the myofibroblast differentiation of pLFs.Surprisingly,we discovered that exosomal HOTAIRM1 enhanced p LF proliferation to secrete excessive collagen secretion,leading to airway obstruction by stimulating the TGF-β/SMAD3 signaling pathway.Significantly,PM_(2.5)reduced FEV1/FVC and FEV1 and increased the level of serum exosomal HOTAIRM1 in healthy people;moreover,serum exosomal HOTAIRM1 was associated with PM_(2.5)-related reductions in FEV1/FVC and FVC.These findings show that PM_(2.5)triggers alterations in exosome components and clarify that one of the paracrine mediators of myofibroblast differentiation is bronchial epithelial cell-derived HOTAIRM1,which has the potential to be an effective prevention and therapeutic target for PM_(2.5)-induced COPD.

关键词： PM2.5 exosomal lncRNAs HOTAIRM1 chronic obstructive pulmonary disease

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Towards Data-Driving Multi-View Evaluation Framework for Scratch

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Tsinghua Science and Technology 2024年第2期29卷 517-528页

作者： Xiaolin Chai yan Sun yan Gao Department of Computer Science Beijing University of Posts and TelecommunicationBeijing 100876China Intellectual Property Institute Shandong Polytechnic CollegeJining 272067China

As one of the most popular visual programming languages,Scratch has a lot of evaluation around it.Reasonable evaluation can help programmers understand their projects better.At the same time,it can also provide a reference for them to browse other projects in the online community.Most of the existing evaluations on Scratch are carried from three perspectives:Computational Thinking(CT)ability,visual presentation aesthetics,and code quality.Among them,the assessment of CT and code quality is mainly carried out from the program script,while the evaluation of visual aesthetics is analyzed from the perspective of image sequences generated by project execution.The single-view evaluation focuses on the performance of a program in a certain aspect and is one-sided.In this paper,we propose a multi-view evaluation framework to integrate various evaluations using different policies.We quantitatively analyze the assessment of different views driven by data.Combined with overall evaluations that represent human opinions,we analyze their differences and connections.Through experiments,we determine the weights of different integration policies,the proposed multi-view evaluation method can generate evaluation results similar to human opinions.

关键词： Scratch Computational Thinking(CT) visual aesthetic static analysis integration policy machine learning

Mass-produced and uniformly luminescent photochromic fibers toward future interactive wearable displays

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Light(Science & Applications) 2024年第4期13卷 593-595页

作者： yan Li Yikai Su Department of Electronic Engineering Shanghai Jiao Tong University200240 ShanghaiChina

Enabling flexible fibers with light-emitting capabilities has the potential to revolutionize the design of smart wearable interactive devices.A recent publication in Light Science&Application,an interdisciplinary team of scientists led by Prof.yan-Qing Lu and Prof.Guangming Tao has realized a highly flexible,uniformly luminescent photochromic fiber based on a mass-produced thermal drawing method.It overcomes the shortcomings of existing commercial lightdiffusing fibers,exhibiting outstanding one-dimensional linear illumination performance.The research team integrated controllable photochromic fibers into various wearable interaction interfaces,providing a novel approach and insights to enable human-computer interaction.

关键词： interaction. fibers uniformly

Effects of different concentrations of nicotinamide on hematopoietic stem cells cultured in vitro

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World Journal of Stem Cells 2024年第2期16卷 163-175页

作者： yan Ren yan-Ni Cui Hong-Wei Wang The Second Clinical Medical College Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Hematology The Second Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Hematology Key Laboratory of Molecular Diagnosis and Treatment of Blood Diseases in Shanxi ProvinceTaiyuan 030001Shanxi ProvinceChina

BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital resource.Nicotinamide(NAM)can promote HSC expansion ex vivo,but its effect on hematopoietic stem and progenitor cells(HSPCs,CD34^(+)CD38)and functional subtypes of HSCs-shortterm repopulating HSCs(ST-HSCs,CD34^(+)CD38CD45RACD49f^(+))and long-term repopulating HSCs(LT-HSCs,CD34^(+)CD38CD45RACD49f^(+)CD90^(+))is not yet known.As a sirtuin 1(SIRT1)inhibitor,NAM participates in regulating cell adhesion,polarity,migration,proliferation,and differentiation.However,SIRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or cells.We propose that the concentration of NAM may influence proliferation,differentiation,and SIRT1 signaling of HSCs.AIM To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and differentiation.METHODS CD34^(+)cells were purified from umbilical cord blood using MacsCD34 beads,and cultured for 10-12 d in a serum-free medium supplemented with cytokines,with different concentrations of NAM added according to experimental requirements.Flow cytometry was used to detect phenotype,cell cycle distribution,and apoptosis of the cultured cells.Real-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors,che mokines,components of hypoxia pathways,and antioxidant enzymes.Dichloro-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species(ROS).Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead array.RESULTS Compared with the control group,the proportion and expansion folds of HSPCs(CD34^(+)CD38)incubated with 5 mmol/L or 10 mmol/L NAM were significantly increased(all P<0.05).The ST-HSCs ratio and fold expansion of the 5 mmol/L NAM group were significantly higher than those of the control and 10 mmol/L N

关键词： Hematopoietic stem cells Nicotinamide Concentration Proliferation Differentiation Sirtuin 1

Electromagnetic characteristic analysis and design of a linear motor used for ultra-high-speed EMS maglev train

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Science China Technological Sciences 2024年第6期67卷 1957-1973页

作者： GAO Han SHI TingNa GAO XinMai LEI yanXiao yan Dong GUO Liyan yan yan College of Electrical Engineering Zhejiang University Zhejiang University Advanced Electrical Equipment Innovation Center State Key Laboratory of High-speed Maglev Transportation Technology CRRC Qingdao Sifang Co.Ltd.

The operating speed of the commercial electromagnetic suspension(EMS) maglev train has been over 430 km/h, making it the fastest means of land transportation. With the increasing demands of people traveling, it is necessary to further improve the operating speed of maglev trains. Aiming to examine whether the existing EMS system can meet the requirements of ultra-highspeed operation(more than 600 km/h), the electromagnetic characteristics of an EMS linear motor under the operating speed of 600–1000 km/h fed by a square-wave voltage supply is investigated in this article. First, an electromagnetic field model of the EMS system under the square-wave voltage supply is established to investigate its electromagnetic performance, e.g., the characteristics of phase current, the magnetic flux density, and the electromagnetic force. Second, the relationship between the harmonic components of the air-gap magnetic flux density and electromagnetic force is investigated using the two-dimensional fast Fourier transform(2D-FFT) to reveal the mechanism of electromagnetic force ripple. Third, to address the issues of excessive armature current density and significant electromagnetic force ripple, the linear motor is re-designed by enlarging the stator slot area and reshaping the mover’s main magnetic poles. Furthermore, the Taguchi method is used to further improve the electromagnetic characteristics of the linear electric motor. Finally, the effectiveness of the proposed optimal design is validated by the finite-element analysis(FEA) based co-simulation.

关键词： ultra-high-speed maglev transportation electromagnetic suspension (EMS) linear motor electromagnetic force ripple suppression

Research on Modeling and Parameter Identification of Comprehensive Load Model of Distribution Network in Industrial Park

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Chinese Journal of Electronics 2024年第1期33卷 264-273页

作者： Tingling WANG Xiaohe yan School of Electric Engineering North China University of Water Resources and Electric Power Wenzhou Polytechnic

With the rapid development of industrial parks, its load model research has become a hot spot. In order to study the load of power system in industrial park, based on the characteristics of the industrial park load, a comprehensive load admittance static model with full voltage range adaptability is considered, and a comprehensive load model of distribution network of the industrial park is established. A complete parameter identification of the model is carried out through chaos particle swarm optimization. The simulation results show that the model can effectively describe the load characteristics of the distribution network in industrial parks.

关键词： Industrial park Comprehensive load model Distribution network Chaos particle swarm optimization

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

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China Foundry 2024年第1期21卷 82-90页

作者： Kun Gao yan Peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting process.The effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in detail.In each rotation,the casting wheel passes through four different spray zones.The results show that the temperature distribution of the casting wheel in different spray zones is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray zoneⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2 MPa and 1.82 mm,respectively.The temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray zones

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Topology Optimization of Two Fluid Heat Transfer Problems for Heat Exchanger Design

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1949-1974页

作者： Kun yan Yunyu Wang Jun yan School of Chemical Engineering Dalian University of TechnologyDalian116024China Jianghuai Advanced Technology Center Hefei230000China State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsInternational Research Center for Computational MechanicsDalian University of TechnologyDalian116024China

Topology optimization of thermal-fluid coupling problems has received widespread attention.This article proposes a novel topology optimization method for laminar two-fluid heat exchanger design.The proposed method utilizes an artificial density field to create two permeability interpolation functions that exhibit opposing trends,ensuring separation between the two fluid domains.Additionally,a Gaussian function is employed to construct an interpolation function for the thermal conductivity coefficient.Furthermore,a computational program has been developed on the OpenFOAM platform for the topology optimization of two-fluid heat exchangers.This program leverages parallel computing,significantly reducing the time required for the topology optimization process.To enhance computational speed and reduce the number of constraint conditions,we replaced the conventional pressure drop constraint condition in the optimization problem with a pressure inlet/outlet boundary condition.The 3D optimization results demonstrate the characteristic features of a surface structure,providing valuable guidance for designing heat exchangers that achieve high heat exchange efficiency while minimizing excessive pressure loss.At the same time,a new structure appears in large-scale topology optimization,which proves the effectiveness and stability of the topology optimization program written in this paper in large-scale calculation.

关键词： Topology optimization two fluid heat exchanger OpenFOAM large scale