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Enzymatic self-assembly/disassembly turns “ON”/“OFF” the mimetic hydrolytic activity of histidine nanofibers

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science China Chemistry 2024年第2期67卷 517-522页

作者： Xianbao Sun Manli Wang Xiaoyang Liu Wenjun Zhan Guangqiong Xu Qiaochu Jiang Hai-Dong Xu Fuqiang Wang Gaolin Liang State Key Laboratory of Digital medical engineering School of Biological Science and Medical EngineeringSoutheast UniversityNanjing210096China Analysis Center Nanjing Medical UniversityNanjing210029China

Mimetic enzymes are devised as alternates or supplements of natural enzymes in broad fields but regulating their activities in a switchable manner remains ***,we proposed an enzymatic self-assembly/disassembly strategy to address this issue.A peptide molecule Nap FFEYIH(YH) was rationally designed which,after self-assembling into nanofibers,lined up the histidine moieties to form active hydrolysis centers for mimicking hydrolase *** dephosphorylation of Nap FFEYp IH(Yp H) by alkaline phosphatase to yield YH also turned “ON” the hydrolase *** turn,phosphorylation of YH by phosphokinase epidermal growth factor receptor to yield Yp H disassembled the nanofibers and thus turned the activity “OFF”.As such,the “ON”/“OFF” of the mimetic hydrolase activities could be regulated under physiological conditions through ALP/EGFR-mediated self-assembly/disassembly of histidine *** work provides a feasible strategy for the on-demand fabrication of artificial enzymes with controllable and superior activities.

关键词： disassembly hydrolytic activity mimetic enzyme phosphorylation self-assembly

Effect of mechanical stresses on degradation behavior of high-purity magnesium in bone environments

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Journal of Materials science & Technology 2024年第4期171卷 252-261页

作者： Yan Yao Jie Xia Lizhen Wang Yuanming Gao Xili Ding Chao Wang Yubo Fan Key Laboratory of Biomechanics and Mechanobiology(Beihang University) Ministry of EducationBeijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringSchool of Engineering MedicineBeihang UniversityBeijing 100083China

High-purity(HP)magnesium(Mg)has emerged as a promising biomaterial for supporting functional bone *** previous study found that mechanical stresses and the surrounding fibrotic tissue(subcuta-neous)both play crucial roles in the degradation of HP ***,due to challenges in the degradation and regeneration process in vivo,it remains unclear how stress affects HP Mg degradation in bone en-vironments,limiting its further *** this study,novel loading devices were designed and the effects of tensile and compressive stresses on HP Mg degradation in vivo and in vitro bone environments were quantitatively *** addition,bone osteointegration around HP Mg was explored *** stress increases the degradation rate of HP Mg in vivo and in *** Mg degradation in vivo is more sensitive to stress factors than in vitro,but the sensitivity decreases with corrosion *** volume loss rate of HP Mg is multilinear with the applied stress and degradation *** volume of bone tissue surrounding HP Mg is larger in the no-stress group compared to the stressed groups,which is more pronounced with increasing implantation *** results provide valuable insights for optimiz-ing the design of HP Mg-based implants considering load *** will help to achieve a balance between the degradation rate of the implant and the regeneration rate of the surrounding bone.

关键词： High-purity magnesium Quantitative stresses Degradation Bone environments In vivo and in vitro

Visualizing Wallerian degeneration in the corticospinal tract after sensorimotor cortex ischemia in mice

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Neural Regeneration Research 2024年第3期19卷 636-641页

作者： Jiao Mu Liufang Hao Zijue Wang Xuyang Fu Yusen Li Fei Hao Hongmei Duan Zhaoyang Yang Xiaoguang Li Beijing Key Laboratory for Biomaterials and Neural Regeneration School of Biological Science and Medical EngineeringBeihang UniversityBeijingChina Department of Neurobiology School of Basic Medical SciencesCapital Medical UniversityBeijingChina

Stroke can cause Wallerian degeneration in regions outside of the brain,particularly in the corticospinal *** investigate the fate of major glial cells and axons within affected areas of the corticospinal tract following stroke,we induced photochemical infarction of the sensorimotor cortex leading to Wallerian degeneration along the full extent of the corticospinal *** first used a routine,sensitive marker of axonal injury,amyloid precursor protein,to examine Wallerian degeneration of the corticospinal *** antibody to amyloid precursor protein mapped exclusively to proximal axonal segments within the ischemic cortex,with no positive signal in distal parts of the corticospinal tract,at all time *** improve visualization of Wallerian degeneration,we next utilized an orthograde virus that expresses green fluorescent protein to label the corticospinal tract and then quantitatively evaluated green fluorescent protein-expressing *** this approach,we found that axonal degeneration began on day 3 post-stroke and was almost complete by 7 days after *** addition,microglia mobilized and activated early,from day 7 after stroke,but did not maintain a phagocytic state over ***,astrocytes showed relatively delayed mobilization and a moderate response to Wallerian ***,no anterograde degeneration of spinal anterior horn cells was observed in response to Wallerian degeneration of the corticospinal *** conclusion,our data provide evidence for dynamic,pathogenic spatiotemporal changes in major cellular components of the corticospinal tract during Wallerian degeneration.

关键词： corticospinal tract green fluorescent protein microglia spinal anterior horn cells stroke virus trace Wallerian degeneration

Comparative assessment of liver tissue:from microstructural and mesoscale vascular architecture to macroscopic mechanics

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Acta Mechanica Sinica 2024年第7期40卷 195-205页

作者： Wei Kang Kaixin Sun Lizhen Wang Yubo Fan Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education Beijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringBeihang UniversityBeijing 100083China school of engineering Medicine Beihang UniversityBeijing 100083China

Accurately characterizing the liver's mechanical properties is of paramount importance for disease diagnosis,treatment,surgical prosthetic modeling,and impact injury ***,due to its inherent biological soft tissue nature,the characterization of mechanical behavior varies across testing methods and sample *** this study,we employed transmission electron microscope and Micro CT to observe the morphology of the marginal and center of rat livers and conducted macroscopic mechanical tests to characterize their elasticity and *** results revealed that the central region displayed higher metabolic levels,elongated mitochondria,and an abundance of rough endoplasmic reticulum at the *** the mesoscale,larger diameter portal veins were mainly distributed in the central region,while smaller diameter arteries were predominantly located at the *** the macroscale,under a strain rate of 0.0167 s^(-1),no significant differences were observed in the elastic properties between the two ***,as the strain rate increased up to 0.167 s^(-1),the central region displayed higher porosity,resulting in reduced liquid loss,increased hardness,and higher viscosity compared to the ***,the liver demonstrated overall heterogeneity,with isotropic models suitable for the peripheral region,while more intricate models may be required to capture the complexity of the central region with its intricate vasculature.

关键词： Liver Mechanical properties Micro and macro tests

Doped microspheres for whispering gallery mode microlasing

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science Bulletin 2024年第13期69卷 2021-2024页

作者： Xiaoxuan Wang Chaoyang Huang Chuansheng Xia Feifei Qin Gangyi Zhu Lingfeng Mao Yi Ma Zengliang Shi Qiannan Cui Chunxiang Xu State Key Laboratory of Digital medical engineering School of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China school of Electronic science and engineering Southeast UniversityNanjing 210096China Peter Grünberg Research Centre College of Telecommunications and Information EngineeringNanjing University of Posts and TelecommunicationsNanjing 210003China

Whispering gallery mode(WGM)optical microcavities,which are capable of light field confinement and manipulation in a relatively small volume,have gained considerable attention from fundamentals in enhanced light-matter interactions to laser applications[1].Undergoing decades of development,the improvement of lasing performance is always a significant issue,including low threshold and high quality(Q)factor[2].Increasing optical gain and reducing the losses are the key aspects towards the realization of a high-quality WGM laser.A perfect cavity structure and a smooth surface are the most crucial determinants to reduce optical losses and enhance light field confined abilities.

关键词： optical lasing mode

Additives strategies to improving cycling stability of Li metal batteries by modifying electrode electrolyte interphases

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Progress in Natural science:Materials International 2024年第2期34卷 338-344页

作者： Yuan Li Pengfei Huang Chunyu Cui Xiaoyuan Ma Li Chen Zekun Li Linhai Li Yuhong Tian school of biological and Chemical engineering Guangxi University of Science and Technology school of College of Chemistry and Chemical engineering Hunan University Isky Future Energy Institute

Li metal batteries（LMBs） have attracted much attention due to the ultra-high theoretical capacity of the Li metal anode（LMA）.However,the uncontrollable dendrites growth and low coulombic efficiency hinder their practical ***,we explore 3,5-difluoropyridine（2F-BD） as a novel electrolyte additive to enable highperformance *** 2F-BD additive participates in and modifies the solvation structure of Li ions by reducing the coordinated number of PF6-at the electrode surface,leading to the formation of a LiF and Li3N-rich solid electrolyte interphase（SEI）.The LiF component increases the robustness of SEI and suppresses the formation of Li dendrites,while the Li3N component facilitates the transportation and reaction kinetics of Li *** a result,the Li‖Li symmetric cell presents a stable cycling performance of up to 500 h at a current density of 1 mA *** coupling with LiFePO4cathode,the obtained full cell achieves high specific capacities of 106.06 mA h g-1and 84.98 mA h g-1at 2.55 mA cm-2and 5.10 mA cm-2,respectively,and maintains a high capacity retention of84.0% after 1000 cycles at 0.13 mA cm-2,with an average cycling CE of 99.58%.

关键词： Li metal batteries Li dendrites Electrolyte additive

Engineered exosome hybrid copper nanoscale antibiotics facilitate simultaneous self-assembly imaging and elimination of intracellular multidrug-resistant superbugs

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Chinese Chemical Letters 2024年第7期35卷 319-324页

作者： Zengchao Guo Weiwei Liu Tengfei Liu Jinpeng Wang Hui Jiang Xiaohui Liu Yossi Weizmann Xuemei Wang State Key Laboratory of Digital medical engineering School of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China Department of Chemistry Ben-Gurion University of the NegevBeer-Sheva 8410501Israel

With the increasing emergence of bacterial infections,especially multidrug-resistant(MDR)bacteria,poses an urgent *** study demonstrated a novel multifunctional nanotheranostics platform developed by the strategic integration of both in-situ bio-assembly imaging and target bacteria *** the introduction of copper ions into bacteria,the Cu^(2+)could spontaneously bio-selfassembled into a multifunctional copper nanoclusters(NCs)which efficiently enhanced epigallocatechin gallate(EGCG)uptake into *** visualizing the bacteria,the developed theranostic nanoplatform exhibited highly efficient disinfection activities with negligible side effects as reflected by higher cell viability and insignificant hemolytic ***,the exosomal formulation of EGCG integrated with Cu^(2+)showed an increased intracellular antibacterial activity,which could eliminate most of the methicillin-resistant Staphylococcus aureus(MRSA)phagocytosed by macrophages,guide macrophages toward M2-like phenotype polarization and alleviate inflammation,without exhibiting obvious cytotoxicity on host *** regimen could be viewed as an effective strategy for the sterilization of intractable bacterial infections.

关键词： In situ self-assembled Exosome Antibacterial agents Bioimaging Intracellular infection

Responses of osteoblasts under varied tensile stress types induced by stretching basement materials

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International Journal of Smart and Nano Materials 2024年第2期15卷 279-295页

作者： Xuezheng Geng Qiao Li Yan Yao Lizhen Wang Yubo Fan Beijing Advanced Innovation Center for Biomedical engineering School of Biological Science and Medical EngineeringKey Laboratory of Biomechanics and Mechanobiology(Beihang University)Ministry of EducationBeijingChina school of engineering Medicine Beihang UniversityBeijingChina

Osteoblasts are mechanosensitive *** stress with different conditions,including loading time,frequency,magnitude,*** cause varied responses in ***,it was not clarified that the effect of the loading types on the *** this study,we focused on the effect of varied tensile stress types on osteoblasts,including isotropic stretch,biaxial stretch,and uniaxial stretch with the negative ratio of transverse strain to axial strain(NR)-1,0,and 0.2 *** proliferation was determined to be most efficient when stimulated by 6%strain at a frequency of 1 Hz and a negative value of 0 for 1 h/*** varied strain resulted in a thickening of the F-actin cytoskeleton and a thinning of the *** flattening caused Yes-associated protein(YAP)to be transported to the *** was suggested that the influence of loading types on the mechanobiology responses must be *** mechanism of cell mechanical sensitivity under varied loading types was explored,which would provide good sugges-tions for designing microstructures to control deformation patterns in bone tissue engineering.

关键词： MC3T3-E1 tensile stress negative poisson’s ratio cell proliferation YAP

Accurate expression of neck motion signal by piezoelectric sensor data analysis

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Chinese Chemical Letters 2024年第9期35卷 250-256页

作者： Neng Shi Haonan Jia Jixiang Zhang Pengyu Lu Chenglong Cai Yixin Zhang Liqiang Zhang Nongyue He Weiran Zhu Yan Cai Zhangqi Feng Ting Wang State Key Laboratory of Digital medical engineering National Demonstration Center for Experimental Biomedical Engineering EducationSchool of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China SceneRay Co. Ltd.Suzhou 215123China school of Chemistry and Chemical engineering Nanjing University of Science and TechnologyNanjing 210094China

The development of high-precision sensors using flexible piezoelectric materials has the advantages of high sensitivity,high stability,good durability,and *** main problem with sensing equipment is low sensitivity,which is due to the mismatch between materials and analysis methods,resulting in the inability to effectively eliminate *** address this issue,we developed the denoising analysis method to motion signals captured by a flexible piezoelectric sensor fabricated from poly(l-lactic acid)(PLLA)and polydimethylsiloxane(PDMS)*** results demonstrate that this improved denoising method effectively removes noise components from neck muscle motion signals,thus obtaining high-quality,low-noise motion signal *** decomposition and reconstruction is a signal processing technique that involves decomposing a signal into different scales and frequency components using wavelets and then selectively reconstructing the signal to emphasize specific features or eliminate *** study employed the sym8 wavelet basis for wavelet decomposition and *** the denoised signals,a high degree of stability and periodic peaks are distinctly manifested,while amplitude and frequency differences among different types of movements also become noticeably *** a result of this study,we are enabled to accurately analyze subtle variations in neck muscle motion signals,such as nodding,shaking the head,neck lateral flexion,and neck *** temporal and frequency domain analysis of denoised motion signals,differentiation among various motion states can be ***,this improved analytical approach holds broad application prospects across various types of piezoelectric sensors,such as healthcare monitoring,sports biomechanics.

关键词： Piezoelectric transducer Wavelet decomposition Muscle motion signal Signal analysis Noise component Healthcare monitoring