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A unified viscoplasticity constitutive model based on irreversible thermodynamics

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Science China(Technological Sciences) 2008年第4期51卷 378-385页

作者： lIU ChangChun lü hexiang GUAN Ping State Key laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Prediction&Control Key laboratory on Complicated Structure System Dalian UniversityDalian 116622China

A unified viscoplasticity constitutive model for metal materials is developed within the framework of irreversible thermodynamics, and an expression for the Helmholtz free energy function involving the parameters reflecting kinematic hardening and isotropic hardening is given. At the same time a non-associated flow potential function including the corresponding state variables is also given, from which the flow equation and the evolution equations of the internal state variables are derived. Thus, a general theoretical framework constructing a unified viscoplasticity constitutive model is given. Compared with the typical unified viscoplasticity constitutive models, the presented model evidently satisfies the irreversible thermodynamics laws. Moreover, this method not only provides a new theoretical foundation for further development of the unified viscoplasticity constitutive model, but also gives a new theoretical framework for the stress-strain analysis of more materials.

关键词： irreversible thermodynamics viscoplasticity unified constitutive kinematic hardening isotropic hardening

Geometric and defects engineering collaboration for enhanced cascade enzymatic nanoreactors

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Nano Research 2024年第4期17卷 2451-2461页

作者： Zhichao Yu Ruijin Zeng hexiang Gong Yuan Gao Shuyun Chen Yunsen Wang Dianping Tang Key laboratory for Analytical Science of Food Safety and Biology(MOE&Fujian Province) Department of ChemistryFuzhou UniversityFuzhou 350108China

Highly evolved multi-enzyme cascade catalytic reactions in organisms facilitate rapid transfer of substrates and efficient conversion of intermediates in the catalytic unit,thus rationalizing their efficient biocatalysis.In this study,pore-ordered mesoporous single-atom(Fe)nitrogen-doped carbon nanoreactors(Mp-Fe-CN)were designed,in which a reasonable pore size was designed as a natural enzyme trap coupled to a simulated enzyme center.A polarity-mediated strategy was developed to obtain atomically dispersed nanoporous substrates,with the finding that polarity-guided engineering of the nitrogen-ligand environment and vacancy cluster defects clearly affects nanoporous activity,accompanied by appreciable mesoporous pore size elevation.The active center and distal N atom coordination of Fe-N_(4) affect the catalytic process of the nanozyme exposed by density functional theory(DFT),determining the contribution of hybridized orbitals to electron transfer and the decisive step.A cascade nanoreactor-based domain-limited sarcosine oxidase developed for non-invasive monitoring of sarcosine levels in urine for evaluation of potential prostate carcinogenesis as a proof of concept.Based on the design of surface mesoporous channels of nanocatalytic units,a bridge was built for the interaction between nanozymes and natural enzymes to achieve cascade nanocatalysis of natural enzymatic products.

关键词： nanozyme single-atom catalyst bioreactor cascade catalysis non-Invasive sensing

Screening and identifying natural products with SARS-CoV-2 infection inhibitory activity from medicinal fungi

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Biosafety and Health 2024年第1期6卷 12-20页

作者： Shuang Zhao Amelia Siqi Huang Weibo Zhang lili Ren hexiang Wang Jianbin Wang Xinyang Shao Guanbo Wang Institute of Agri-Food Processing and Nutrition Institute of Plant ProtectionBeijing Academy of Agriculture and Forestry SciencesBejing 100097China Bejing Key laboratory of Fruits and Vegetable Storage and Processing Key Laboratory of Vegetable Postharvest ProcessingMinistry of AgricultureBejing 100097China Dalton Academy The Affliated High School of Peking UniversityBeijing 100190China NHC Key laboratory of Systems Biology of Pathogens and Christophe Merieux laboratory National Institute of Pathogen BiologyBejing 100730China Key laboratory of Respiratory Disease Pathogenomics Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China College of Biological Sciences China Agricultural UniversityBejing 100193China School of life Sciences Tsinghua UniversityBeijing 100084China Changping laboratory Beijing 102206China Institute for Cell Analysis Shenzhen Bay LaboratoryShenzhen 518132China

The coronavirus disease of 2019(COVID‐19),a global pandemic caused by the severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2),can result in severe health complications.In addition to physical preventative measures,pharmaceutical intervention is also crucial.Numerous natural products from medicinal fungi have shown promise as potential antiviral drugs and may serve as a source of effective components with antiviral activity against SARS‐CoV‐2 and other coronaviruses.In this study,we developed a workflow that integrates viral infection inhibition assays at both cellular and molecular levels,as well as molecular separation and characterization,to screen and identify natural products with antiviral activity.Using this workflow,we screened 167 extracts extracted from 36 medicinal fungi using optimized extraction methods.We assessed the antiviral effects of these extracts by measuring their ability to inhibit SARS‐CoV‐2 infection and receptor binding domain‐human angiotensin‐converting enzyme 2(RBD‐hACE2)binding in vitro.Following charge‐and size‐based characterization of the active compounds through filtration and chromatographic fractionation,mass spectrometry characterization of the fractionated compounds revealed that the active components are polysaccharides and determined their monosaccharide residue composition.Our findings provide new insights into the antiviral potential of natural products and their screening strategies and may contribute to the development of effective antiviral therapeutics against COVID‐19 and other diseases.

关键词： Medicinal fungi Natural products Antiviral activity COVID‐19 Polysaccharides

Modification of food protein fibrils: During and after fibrillization

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Food Science and Human Wellness 2024年

作者： Kefan Ouyang hexiang Xie Hua Xiong Qiang Zhao Wenjun Wang State Key laboratory of Food Science and Resources Nanchang University Jiangxi Key laboratory of Natural Products and Functional Food College of Food Science and Engineering Jiangxi Agricultural University

Fibrillization endows food proteins with anisotropic nanostructures， significantly enhancing their functional properties. The resultant food protein fibrils (FPFs) have garnered attention for their diverse applications across the food industry. However， the full potential of FPFs is hindered by inherent challenges， particularly their limited stability. This review critically examines the formation of FPFs in food processing， the new protein sources， and on the modification strategies of FPFs， thereby unlocking new avenues for FPF utilization in food processing. In particular， the strategies during and after fibrillization are highlighted. The first strategy is to modify the structure and function of protein fibrils by influencing fibrillization， such as through pretreatment， incubation conditions， nuclei induction， and ingredient interactions. The second strategy is to modify the mature FPFs by regulating their properties and interactions with other components. The review also discusses the potential applications and challenges of FPFs in food systems， such as food preservation， functional food design， and novel delivery carriers.

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Method for the extraction of circulating nucleic acids based on MOF reveals cell-free RNA signatures in liver cancer

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National Science Review 2024年第1期11卷 94-106页

作者： Yuqing Sun Haixin Yu Shaoqing Han Ruoxi Ran Ying Yang Yongling Tang Yuhao Wang Wenhao Zhang Heng Tang Boqiao Fu Boshi Fu Xiaocheng Weng Song-Mei liu hexiang Deng Shuang Peng Xiang Zhou College of Chemistry and Molecular Sciences Key Laboratory of Biomedical Polymers-Ministry of Education Wuhan University Department of Digestive Surgical Oncology Union Hospital Tongji Medical College Huazhong University of Science and Technology Cancer Center Union HospitalTongji Medical CollegeHuazhong University of Science and Technology Department of Clinical laboratory Center for Gene Diagnosis and Program of Clinical Laboratory Zhongnan Hospital of Wuhan University College of Chemistry and Materials Science Hubei Engineering University Department of Pharmacology School of Pharmacy China Medical University Taikang Center for life and Medical Sciences Wuhan University Department of Hematology Zhongnan Hospital of Wuhan University

Cell-free RNA(cf RNA) allows assessment of health, status, and phenotype of a variety of human organs and is a potential biomarker to non-invasively diagnose numerous diseases. Nevertheless, there is a lack of highly efficient and bias-free cf RNA isolation technologies due to the low abundance and instability of cf RNA.Here, we developed a reproducible and high-efficiency isolation technology for different types of cell-free nucleic acids(containing cf RNA and viral RNA) in serum/plasma based on the inclusion of nucleic acids by metal-organic framework(MOF) materials, which greatly improved the isolation efficiency and was able to preserve RNA integrity compared with the most widely used research kit method. Importantly, the quality of cf RNA extracted by the MOF method is about 10-fold that of the kit method, and the MOF method isolates more than three times as many different RNA types as the kit method. The whole transcriptome mapping characteristics of cf RNA in serum from patients with liver cancer was described and a cf RNA signature with six cf RNAs was identified to diagnose liver cancer with high diagnostic efficiency(area under curve = 0.905 in the independent validation cohort) using this MOF method. Thus, this new MOF isolation technique will advance the field of liquid biopsy, with the potential to diagnose liver cancer.

关键词： MOF circulating cell-free RNA biomarker liver cancer diagnosis

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多自由度非线性动力学方程的能量校准算法

力学学报 2007年第3期39卷 356-364页

作者：李伟东吕和祥大连理工大学工业装备结构分析国家重点实验室大连116023

针对非线性动力学方程,通过Taylor展开和Duhamel积分,得到一个具有待定参数的逐步积分求解公式;通过数学变换,将原动力学方程转换为一个能确定待定参数的能量校准方程;最后将该参数回代入逐步积分公式,得到数值解．数值算例的结果说明... 详细信息

针对非线性动力学方程,通过Taylor展开和Duhamel积分,得到一个具有待定参数的逐步积分求解公式;通过数学变换,将原动力学方程转换为一个能确定待定参数的能量校准方程;最后将该参数回代入逐步积分公式,得到数值解．数值算例的结果说明了该方法的有效性,可以消除算法阻尼和抑制数值解发散,同时,在大步长的条件下也得到了非常准确而且稳定的结果,可以对系统长期性态进行仿真．

关键词：能量校准方程算法阻尼条件稳定数值积分非线性动力学方程

多尺度深层特征加强的CME小样本目标检测模型

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计算机工程与应用 2024年第6期60卷 222-229页

作者：丁政伟白鹤翔胡深山西大学计算机与信息技术学院太原030006

针对现有的小样本目标检测模型存在对图像全局语义信息考虑不足、输入图像大小不一而导致检测器性能下降的问题,提出了多尺度深层特征加强的CME小样本目标检测模型。利用大量有标签的基类数据和基于残差跳跃的多层卷积神经网络及多尺度... 详细信息

针对现有的小样本目标检测模型存在对图像全局语义信息考虑不足、输入图像大小不一而导致检测器性能下降的问题,提出了多尺度深层特征加强的CME小样本目标检测模型。利用大量有标签的基类数据和基于残差跳跃的多层卷积神经网络及多尺度特征增强模块训练一个泛化性良好的模型,经过少量有标签的新类数据和基类数据对模型微调,利用微调后的模型进行目标检测。为验证模型的有效性,使用VOC2007和VOC2012数据集对模型进行训练和评估,相关消融实验证明了引入残差跳跃结构的多层卷积神经网络和多尺度特征增强模块的单独使用和组合使用均可进一步增加模型的准确率。在与6个具有代表性的小样本目标检测模型的对比实验中表明,多尺度深层特征加深的CME比最先进的检测器得分平均提高4.75个百分点。

关键词：小样本学习目标检测残差跳跃多尺度特征深层特征

Three-Wave Mixing of Dipole Solitons in One-Dimensional Quasi-Phase-Matched Nonlinear Crystals

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Chinese Physics letters 2024年第1期41卷 25-33页

作者：郭宇欣徐晓喜陈招拼周延桂刘彬和河向黎永耀谢嘉宁 School of Physics and Optoelectronic Engineering Foshan UniversityFoshan 528000China Physics Department and Solid-State Institute TechnionHaifa 32000Israel Guangdong-Hong Kong-Macao Joint laboratory for Intelligent Micro-Nano Optoelectronic Technology School of Physics and Optoelectronic EngineeringFoshan UniversityFoshan 528000China

A quasi-phase-matched technique is introduced for soliton transmission in a quadratic[χ^((2))]nonlinear crystal to realize the stable transmission of dipole solitons in a one-dimensional space under three-wave mixing.We report four types of solitons as dipole solitons with distances between their bimodal peaks that can be laid out in different stripes.We study three cases of these solitons:spaced three stripes apart,one stripe apart,and confined to the same stripe.For the case of three stripes apart,all four types have stable results,but for the case of one stripe apart,stable solutions can only be found atω_(1)=ω_(2),and for the condition of dipole solitons confined to one stripe,stable solutions exist only for Type1 and Type3 atω_(1)=ω_(2).The stability of the soliton solution is solved and verified using the imaginary time propagation method and real-time transfer propagation,and soliton solutions are shown to exist in the multistability case.In addition,the relations of the transportation characteristics of the dipole soliton and the modulation parameters are numerically investigated.Finally,possible approaches for the experimental realization of the solitons are outlined.

关键词： soliton solitons dipole

On the functions of astrocyte-mediated neuronal slow inward currents

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Neural Regeneration Research 2024年第12期19卷 2602-2612页

作者： Balázs Pál Department of Physiology Faculty of MedicineUniversity of DebrecenDebrecenHungary

Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events are significantly slower than the excitatory postsynaptic currents.Parameters of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto rs.Astrocytes are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback loop.Mostly as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological conditions.There is a growing body of evidence on the roles of slow inward currents on a single neuron or local network level.These events often occur in synchro ny on neurons located in the same astrocytic domain.Besides synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic plasticity.In addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory inputs.Of note,there might be important regionspecific differences in the roles and actions triggering slow inward currents.In greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological ones.Slow inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural networks.Slow inward currents are significant contributors to paroxysmal depolarizational shifts/interictal spikes.These events are related to epilepsy,but also found in Alzheimer's disease,Parkinson's disease,and stroke,leading to the decline of cognitive functions.Events with features overlapping with slow inward currents(excitatory,N-methyl-Daspartate-receptor mediated currents with astrocyti

关键词： astrocyte cortical spreading depolarization gliotransmission glutamate neural synchronization NMDA receptor paroxysmal depolarizational shift slow inward current