检索结果-南通市图书馆

China Foundry 2024年第1期21卷 29-43页

作者： zhao-yang yin Qi-chi Le Yan-chao Jiang Da-zhi zhao Qi-yu Liao Qi Zou Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

A transient 3D model was established to investigate the effect of spatial interaction of ultrasounds on the dual-frequency ultrasonic field in magnesium alloy melt.The effects of insertion depth and tip shape of the ultrasonic rods,input pressures and their ratio on the acoustic field distribution were discussed in detail.Additionally,the spacing,angle,and insertion depth of two ultrasonic rods significantly affect the interaction between distinct ultrasounds.As a result,various acoustic pressure distributions and cavitation regions are obtained.The spherical rods mitigate the longitudinal and transversal attenuation of acoustic pressure and expand the cavitation volume by 53.7%and 31.7%,respectively,compared to the plate and conical rods.Increasing the input pressure will enlarge the cavitation region but has no effect on the acoustic pressure distribution pattern.The acoustic pressure ratio significantly affects the pressure distribution and the cavitation region,and the best cavitation effect is obtained at the ratio of 2:1(P15:P20).

关键词： dual-frequency ultrasonic numerical model acoustic pressure spatial interaction magnesium alloy

How plants sense and respond to osmotic stress

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第3期66卷 394-423页

作者： Bo Yu Dai-yin Chao yang zhao Shanghai Center for Plant Stress Biology CAS Center for Excellence in Molecular Plant SciencesThe Chinese Academy of SciencesShanghai 200032China Key Laboratory of Plant Carbon Capture The Chinese Academy of SciencesShanghai 200032China National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyThe Chinese Academy of SciencesShanghai 200032China University of Chinese Academy of Sciences Beijing 100049China

Drought is one of the most serious abiotic stresses to land plants.Plants sense and respond to drought stress to survive under water deficiency.Scientists have studied how plants sense drought stress,or osmotic stress caused by drought,ever since Charles Darwin,and gradually obtained clues about osmotic stress sensing and signaling in plants.Osmotic stress is a physical stimulus that triggers many physiological changes at the cellular level,including changes in turgor,cell wall stiffness and integrity,membrane tension,and cell fluid volume,and plants may sense some of these stimuli and trigger downstream responses.In this review,we emphasized water potential and movements in organisms,compared putative signal inputs in cell wall-containing and cell wall-free organisms,prospected how plants sense changes in turgor,membrane tension,and cell fluid volume under osmotic stress according to advances in plants,animals,yeasts,and bacteria,summarized multilevel biochemical and physiological signal outputs,such as plasma membrane nanodomain formation,membrane water permeability,root hydrotropism,root halotropism,Casparian strip and suberin lamellae,and finally proposed a hypothesis that osmotic stress responses are likely to be a cocktail of signaling mediated by multiple osmosensors.We also discussed the core scientific questions,provided perspective about the future directions in this field,and highlighted the importance of robust and smart root systems and efficient source-sink allocations for generating future high-yield stress-resistant crops and plants.

关键词： cell volume drought membrane tension osmotic stress turgor

Developmental toxicity assessment of neonicotinoids and organophosphate esters with a human embryonic stem cell-and metabolism-based fast-screening model

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第3期137卷 370-381页

作者： Shuxian Zhang Miaomiao zhao Shichang Li Renjun yang Nuoya yin Francesco Faiola State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

In recent years,neonicotinoids(NEOs)and organophosphate esters(OPEs)have been widely used as substitutes for traditional pesticides and brominated fame-retardants,respectively.Previous studies have shown that those compounds can be frequently detected in environmental and human samples,are able to penetrate the placental barrier,and are toxic to animals.Thus,it is reasonable to speculate that NEOs and OPEs may have potential adverse effects in humans,especially during development.We employed a human embryonic stem cell differentiation-and liver S9 fraction metabolism-based fast screening model to assess the potential embryonic toxicity of those two types of chemicals.We show that four NEO and five OPE prototypes targeted mostly ectoderm specification,as neural ectoderm and neural crest genes were down-regulated,and surface ectoderm and placode markers up-regulated.Human liver S9 fraction's treatment could generally reduce the effects of the chemicals,except in a few specific instances,indicating the liver may detoxify NEOs and OPEs.Our findings suggest that NEOs and OPEs interfere with human early embryonic development.

关键词： Neonicotinoids Organophosphate esters Human embryonic stem cells Fast screening model Developmental toxicity

Emerging strategies for nerve repair and regeneration in ischemic stroke:neural stem cell therapy

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第11期19卷 2430-2443页

作者： Siji Wang Qianyan He yang Qu Wenjing yin Ruoyu zhao Xuyutian Wang Yi yang Zhen-Ni Guo Stroke Center Department of Neurologythe First Hospital of Jilin UniversityChangchunJilin ProvinceChina Neuroscience Research Center Department of Neurologythe First Hospital of Jilin UniversityChangchunJilin ProvinceChina Department of Breast Surgery General Surgery Centerthe First Hospital of Jilin UniversityChangchunJilin ProvinceChina

Ischemic stroke is a major cause of mortality and disability worldwide,with limited treatment options available in clinical practice.The emergence of stem cell therapy has provided new hope to the field of stroke treatment via the restoration of brain neuron function.Exogenous neural stem cells are beneficial not only in cell replacement but also through the bystander effect.Neural stem cells regulate multiple physiological responses,including nerve repair,endogenous regeneration,immune function,and blood-brain barrier permeability,through the secretion of bioactive substances,including extracellular vesicles/exosomes.However,due to the complex microenvironment of ischemic cerebrovascular events and the low survival rate of neural stem cells following transplantation,limitations in the treatment effect remain unresolved.In this paper,we provide a detailed summary of the potential mechanisms of neural stem cell therapy for the treatment of ischemic stroke,review current neural stem cell therapeutic strategies and clinical trial results,and summarize the latest advancements in neural stem cell engineering to improve the survival rate of neural stem cells.We hope that this review could help provide insight into the therapeutic potential of neural stem cells and guide future scientific endeavors on neural stem cells.

关键词： bystander effect cell replacement extracellular vesicles ischemic stroke neural stem cells neural stem cell engineering

A sub-grid scale model for Burgers turbulence based on the artificial neuralnetwork method

在线全文

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2024年第3期14卷 162-165页

作者： Xin zhao Kaiyi yin Department of Mechanics Beijing Institute of TechnologyBeijing 100081China

The present study proposes a sub-grid scale model for the one-dimensional Burgers turbulence based on the neuralnetwork and deep learning method.The filtered data of the direct numerical simulation is used to establish thetraining data set,the validation data set,and the test data set.The artificial neural network(ANN)methodand Back Propagation method are employed to train parameters in the ANN.The developed ANN is applied toconstruct the sub-grid scale model for the large eddy simulation of the Burgers turbulence in the one-dimensionalspace.The proposed model well predicts the time correlation and the space correlation of the Burgers turbulence.

关键词： Artificial neural network Back propagation method Burgers turbulence Large eddy simulation Sub-grid scale model

Clinical relevance of distolingual roots and periodontal status in mandibular first molars: a cross-sectional study employing CBCT analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第3期25卷 244-253页

作者： Feifei MAO Meng WANG Shuai ZHOU Yan zhao Jiaping HUANG Fengying yin Haiping yang Pei-hui DING Stomatology Hospital School of StomatologyZhejiang University School of MedicineZhejiang Provincial Clinical Research Center for Oral DiseasesKey Laboratory of Oral Biomedical Research of Zhejiang ProvinceCancer Center of Zhejiang UniversityHangzhou 310016China

Objectives:Distolingual root of the permanent mandibular first molar(PMFM-DLR)has been frequently reported,which may complicate the treatment of periodontitis.This study aimed to assess the morphological features of PMFM-DLR and investigate the correlation between the morphological features of PMFM-DLR and periodontal status in patients with Eastern Chinese ethnic background.Materials and methods:A total of 836 cone beam computed tomography(CBCT)images with 1497 mandibular first molars were analyzed to observe the prevalence of PMFM-DLR at the patients and tooth levels in Eastern China.Among them,complete periodontal charts were available for 69 Chinese patients with 103 teeth.Correlation and regression analyses were used to evaluate the correlation between the morphological features of DLR,bone loss,and periodontal clinical parameters,including clinical attachment loss(CAL),probing pocket depth(PPD),gingival recession(GR),and furcation involvement(FI).Results:The patient-level prevalence and tooth-level prevalence of DLR in mandibular first molars were 29.4%and 26.3%,respectively.Multiple linear regression analysis suggested that bone loss at the lingual site and CAL were negatively affected by the angle of separation between distolingual and mesial roots in the transverse section,while they were significantly influenced by age and the angle of separation between distobuccal and mesial roots in the coronal section.Conclusions:The prevalence of PMFM-DLR in Eastern China was relatively high in our cohort.The morphological features of DLR were correlated with the periodontal status of mandibular first molars.This study provides critical information on the morphological features of DLR for improved diagnosis and treatment options of mandibular molars with DLR.

关键词： Distolingual root Mandibular first molar Periodontal clinical parameter Clinical attachment loss Cone beam computed tomography(CBCT)

Analytical solution for the effective elastic properties of rocks with the tilted penny-shaped cracks in the transversely isotropic background

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 221-243页

作者： Zheng-Qian Ma Xing-Yao yin zhao-Yun Zong Yuan-Yuan Tan Ya-Ming yang National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao266200ShandongChina

Seismic prediction of cracks is of great significance in many disciplines,for which the rock physics model is indispensable.However,up to now,multitudinous analytical models focus primarily on the cracked rock with the isotropic background,while the explicit model for the cracked rock with the anisotropic background is rarely investigated in spite of such case being often encountered in the earth.Hence,we first studied dependences of the crack opening displacement tensors on the crack dip angle in the coordinate systems formed by symmetry planes of the crack and the background anisotropy,respectively,by forty groups of numerical experiments.Based on the conclusion from the experiments,the analytical solution was derived for the effective elastic properties of the rock with the inclined penny-shaped cracks in the transversely isotropic background.Further,we comprehensively analyzed,according to the developed model,effects of the crack dip angle,background anisotropy,filling fluid and crack density on the effective elastic properties of the cracked rock.The analysis results indicate that the dip angle and background anisotropy can significantly either enhance or weaken the anisotropy degrees of the P-and SH-wave velocities,whereas they have relatively small effects on the SV-wave velocity anisotropy.Moreover,the filling fluid can increase the stiffness coefficients related to the compressional modulus by reducing crack compliance parameters,while its effects on shear coefficients depend on the crack dip angle.The increasing crack density reduces velocities of the dry rock,and decreasing rates of the velocities are affected by the crack dip angle.By comparing with exact numerical results and experimental data,it was demonstrated that the proposed model can achieve high-precision estimations of stiffness coefficients.Moreover,the assumption of the weakly anisotropic background results in the consistency between the proposed model and Hudson's published theory for the orthorhombic rock.

关键词： Effective elastic property Tilted crack Transverse isotropy Analytical solution Crack opening displacement

CircPTEN-MT from PTEN regulates mitochondrial energy metabolism

在线全文

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2024年第5期51卷 531-542页

作者： Danhui Ruan Jiancheng Xu yang Liu Juan Luo Xuyang zhao Yuhua Li Guangxi Wang Jiawen Feng Hui Liang Yue yin Jianyuan Luo Yuxin yin Institute of Systems Biomedicine Department of PathologySchool of Basic Medical SciencesBeijing Key Laboratory of Tumor Systems BiologyPeking University International Cancer InstitutePeking-Tsinghua Center of Life SciencesPeking University Health Science CenterBeijing 100191China Institute of Precision Medicine Peking University Shenzhen HospitalShenzhenGuangdong 518036China Department of Pharmacology School of Basic Medical SciencesPeking University Health Science CenterBeijing 100191China Department of Medical Genetics Center for Medical GeneticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing 100191China Soochow University Cancer Institute SuzhouJiangsu 215127China

Phosphatase and tensin homolog(PTEN)is a multifunctional gene involved in a variety of physiological and pathological processes.Circular RNAs(circRNAs)are generated from back-splicing events during mRNA processing and participate in cell biological processes through binding to RNAs or proteins.However,PTEN-related circRNAs are largely unknown.Here,we report that circPTEN-mitochondria(MT)(hsa_circ_0002934)is a circular RNA encoded by exons 3,4,and 5 of PTEN and is a critical regulator of mitochondrial energy metabolism.CircPTEN-MT is localized to mitochondria and physically associated with leucine-rich pentatricopeptide repeat-containing protein(LRPPRC),which regulates posttranscriptional gene expression in mitochondria.Knocking down circPTEN-MT reduces the interaction of LRPPRC and steroid receptor RNA activator(SRA)stem-loop interacting RNA binding protein(SLIRP)and inhibits the polyadenylation of mitochondrial mRNA,which decreases the mRNA level of the mitochondrial complex I subunit and reduces mitochondrial membrane potential and adenosine triphosphate production.Our data demonstrate that circPTEN-MT is an important regulator of cellular energy metabolism.This study expands our understanding of the role of PTEN,which produces both linear and circular RNAs with different and independent functions.

关键词： Circular RNA LRPPRC Mitochondrial energy metabolism mtDNApost-transcriptional regulation

Annexin A1 in the nervous and ocular systems

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第3期19卷 591-597页

作者： Aijia Wang Hong Zhang Xing Li yin zhao Department of Ophthalmology 2Department of AnesthesiologyTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei ProvinceChina

The therapeutic potential of Annexin A1,an important member of the Annexin superfamily,has become evident in results of experiments with multiple human systems and animal models.The anti-inflammatory and pro-resolving effects of Annexin A1 are characteristic of pathologies involving the nervous system.In this review,we initially describe the expression sites of Annexin A1,then outline the mechanisms by which Annexin A1 maintains the neurological homeostasis through either formyl peptide receptor 2 or other molecular approaches;and,finally,we discuss the neuroregenerative potential qualities of Annexin A1.The eye and the nervous system are anatomically and functionally connected,but the association between visual system pathogenesis,especially in the retina,and Annexin A1 alterations has not been well summarized.Therefore,we explain the beneficial effects of Annexin A1 for ocular diseases,especially for retinal diseases and glaucoma on the basis of published findings,and we explore present and future delivery strategies for Annexin A1 to the retina.

关键词： Annexin A1(ANXA1) glaucoma nervous system neuroprotection neuroregeneration ocular disease retina

Mechanical Janus lattice with plug-switch orientation

在线全文

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2024年第1期14卷 23-26页

作者： Yupei Zhang Jiawei Zhong Zhengcai zhao Ruiyu Bai Yanqi yin yang Yu Bo Li State Key Laboratory for Manufacturing System EngineeringShaanxi Key Laboratory of Intelligent Robots School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China Qian Xuesen Honors College Xi’an Jiaotong UniversityXi’an 710049China

In recent years,materials with asymmetric mechanical response properties(mechanical Janus materials)have been found possess numerous potential applications,i.***.shock absorption and vibration isolation.In this study,we propose a novel mechanical Janus lattice whose asymmetric mechanical response can be switched in orientation by a plug.Through finite element analysis and experimental verification,this lattice exhibits asymmetric displacement responses to symmetric forces.Furthermore,with such a plug structure inside,individual lattices can switch the orientation of asymmetry and thus achieve reprogrammable design of a mechanical structure with chained lattices.The reprogrammable asymmetry of this material will offer multiple functions in design of mechanical metamaterials.

关键词： Janus Non-reciprocity Programmability Mechanical metamaterial