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Advancements in the preparation of high-performance liquid chromatographic organic polymer monoliths for the separation of small-molecule drugs 被引量:5
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作者 Xiali Ding Jing Yang Yuming Dong 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2018年第2期75-85,共11页
The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographer... The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency. 展开更多
关键词 HIGH-PERFORMANCE LIQUID chromatography Polymer MONOLITH Preparation methods Small molecules
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Discovery of a small-molecule bromodomain-containing protein 4 inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer 被引量:4
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作者 Jin ZHANG Jie LIU Liang OUYANG 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2017年第10期980-980,共1页
OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mech... OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mechanisms.METHODS BRD4 interactors were analyzed by PPI network prediction and The Cancer Genome Atlas(TCGA)analysis.The interaction between BRD4 and AMPK was confirmed by co-immunoprecipitation assay.Novel BRD4 inhibitors were designed and synthesized based upon pharmacophore analysis of BRD4(1),then screened by antiproliferative activity and Alpha Screen of BRD4(1).The selectivity of the best candidate compound 8f was validated by co-crystallization,FRET assay and co-immuno precipitation assay.The mechanisms of 8f were investigated by fluorescence microscopy,electron microscopy,Western blotting,immunocytochemistry,si RNA and GFP-m RFP-LC3 plasmid transfections,as well as immunohistochemistry and immunofluorescence.Potential mechanisms were discovered by i TRAQ-based proteomics analysis and the therapeutic effect of 8f was assessed by xenograft breast cancer mouse and zebrafish models.RESULTS We identified that BRD4 interacted with AMPK,which was remarkably downregulated in breast cancer.We next designed and synthesized 49 candidate compounds,and eventually discovered a selective small-molecule inhibitor of BRD4(8f).Subsequently,8f was discovered to induce autophagyassociated cell death(ACD)by BRD4-AMPK interaction,and thus activating AMPK-m TOR-ULK1-modulated autophagic pathway in breast cancer cells.Interestingly,the i TRAQ-based proteomics analyses revealed that 8f induced ACD pathways,involved in HMGB1,VDAC1/2 and e EF2.Moreover,8f displayed a therapeutic potential on both xenograft breast cancer mouse and zebrafish models.CONCLUSION We discovered a novel small-molecule inhibitor of BRD4 that induces BRD4-AMPK-modulated ACD in breast cancer,which may provide a candidate drug for future cancer therapy. 展开更多
关键词 bromodomain-containing protein 4(BRD4) BRD4-AMPK interaction small-molecule inhibitor of BRD4 Autophagy-associated cell death(ACD) breast cancer
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Transient Folate Deprivation in Combination with Small-molecule Compounds Facilitates the Generation of Somatic Cell-derived Pluripotent Stem Cells in Mice 被引量:1
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作者 胡文涛 闫秋月 +2 位作者 方瑜 邱占东 张苏明 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2014年第2期151-156,共6页
Induced pluripotent stem cells (iPSCs) can be propagated indefinitely, while maintaining the capacity to differentiate into all cell types in the body except for the extra-embryonic tissues. This iPSC technology not... Induced pluripotent stem cells (iPSCs) can be propagated indefinitely, while maintaining the capacity to differentiate into all cell types in the body except for the extra-embryonic tissues. This iPSC technology not only represents a new way to use individual-specific stem cells for regenerative medicine but also constitutes a novel method to obtain large numbers of disease-specific cells for biomedical re- search. However, the low efficiency of reprogramming and genomic integration of oncogenes and viral vectors limit the potential application of iPSCs. Chemical-induced reprogramming offers a novel ap- proach to generating iPSCs. In this study, a new combination of small-molecule compounds (SMs) (so- dium butyrate, A-83-01, CHIR99021, Y-27632) under conditions of transient folate deprivation was used to generate iPSC. It was found that transient folate deprivation combined with SMs was sufficient to permit reprogramming from mouse embryonic fibroblasts (MEFs) in the presence of transcription factors, Oct4 and Klf4, within 25 days, replacing Sox2 and c-Myc, and accelerated the generation of mouse iPSCs The resulting cell lines resembled mouse embryonic stem (ES) cells with respect to proliferation rate, morphology, pluripotency-associatedmarkers and gene expressions. Deprivation of folic acid, combined with treating MEFs with SMs, can improve the inducing efficiency of iPSCs and reduce their carcino- genicity and the use of exogenous reprogramming factors. 展开更多
关键词 folic acid deprivation small-molecule compounds induced pluripotent stem cells
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Efficient small-molecule donor with improved structural order and molecular aggregation enabled by side-chain modification 被引量:1
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作者 Haiyan Chen Ke Yang +5 位作者 Peihao Huang Dingqin Hu Hua Tang Jie Lv Gang Li Shirong Lu 《Materials Reports(Energy)》 2021年第4期54-60,共7页
Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvem... Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvement,including molecular microstructure,orientating packing and aggregation are urgent for all-small-molecule(ASM)systems.Herein,employing a fluorine-modified two-dimension benzodithiophene(BDT)as central unit,we contrastively synthesized two small-molecule donors,namely BDT-F-SR and BDT-F-R,each welding alkylthio side-chains on thienyl of central BDT unit and the other grafted non-sulfuric alkyl side-chains.As predicted,the synergetic side-chain modification of fluorination and alkyl changeover triggers diverse molecular dipole moments and orientations,resulting in different molecular energy levels,thermal stabilities,molecular planarity and order.Eventually,together with the preeminent small-molecule acceptor Y6,BDT-F-R-based ASM OSCs obtain enhanced power conversion efficiency(PCE)of 13.88%compared to BDT-F-SR-based devices(PCE of 12.75%)with more suitable phase-separation and balanced carrier mobilities.The contrast results reveal that alkyl sidechains seem to be a more satisfactory partner for fluorine-modified 2D BDT-based small-molecule donors compared to alkylthio pendants,and highlight the significance of subtle side-chain modification for molecular structural order fun-tuning and morphology control,laying the foundation for efficient ASM OSCs. 展开更多
关键词 Organic solar cell small-molecule donor Side-chain modification Molecular dipole moment MORPHOLOGY
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A Review on Sources,Extractions and Analysis Methods of a Sustainable Biomaterial:Tannins 被引量:2
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作者 Antonio Pizzi Marie-Pierre Laborie Zeki Candan 《Journal of Renewable Materials》 EI CAS 2024年第3期397-425,共29页
Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly ... Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses. 展开更多
关键词 TANNINS FLAVONOIDS SOURCES extraction methods analysis methods
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Design,synthesis,and evaluation of fluoroquinolone derivatives as microRNA-21 small-molecule inhibitors
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作者 Yuan-Yuan Hei Si Wang +6 位作者 Xiao-Xiao Xi Hai-Peng Wang Yuanxu Guo Minhang Xin Congshan Jiang Shemin Lu San-Qi Zhang 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2022年第4期653-663,共11页
MicroRNA-21(miRNA-21)is highly expressed in various tumors.Small-molecule inhibition of miRNA-21 is considered to be an attractive novel cancer therapeutic strategy.In this study,fluoroquinolone derivatives A1eA43 wer... MicroRNA-21(miRNA-21)is highly expressed in various tumors.Small-molecule inhibition of miRNA-21 is considered to be an attractive novel cancer therapeutic strategy.In this study,fluoroquinolone derivatives A1eA43 were synthesized and used as miRNA-21 inhibitors.Compound A36 showed the most potent inhibitory activity and specificity for miRNA-21 in a dual-luciferase reporter assay in HeLa cells.Compound A36 significantly reduced the expression of mature miRNA-21 and increased the protein expression of miRNA-21 target genes,including programmed cell death protein 4(PDCD4)and phosphatase and tensin homology deleted on chromosome ten(PTEN),at 10 μM in HeLa cells.The Cell Counting Kit-8 assay(CCK-8)was used to evaluate the antiproliferative activity of A36;the results showed that the IC_(50) value range of A36 against six tumor cell lines was between 1.76 and 13.0 μM.Meanwhile,A36 did not display cytotoxicity in BEAS-2B cells(lung epithelial cells from a healthy human donor).Furthermore,A36 significantly induced apoptosis,arrested cells at the G_(0)/G_(1) phase,and inhibited cell-colony formation in HeLa cells.In addition,mRNA deep sequencing showed that treatment with A36 could generate 171 dysregulated mRNAs in HeLa cells,while the expression of miRNA-21 target gene dual-specificity phosphatase 5(DUSP5)was significantly upregulated at both the mRNA and protein levels.Collectively,these findings demonstrated that A36 is a novel miRNA-21 inhibitor. 展开更多
关键词 Quinolone derivatives small-molecule miRNA-21 inhibitor Antitumor agent Drug design
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Small-Molecule Ligands as Challenge for Positron Emission Tomography of Peptide Receptors in Neurons and Microglia of the Brain
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作者 Margit Pissarek 《World Journal of Neuroscience》 2019年第4期294-327,共34页
Neuropeptide and chemokine receptors of the G protein-coupled receptor (GPCR) family belong to different classes and subgroups providing different docking sites and special binding behavior at extracellular and also t... Neuropeptide and chemokine receptors of the G protein-coupled receptor (GPCR) family belong to different classes and subgroups providing different docking sites and special binding behavior at extracellular and also transmembrane domains for small molecules potentially suitable for positron emission tomography (PET). The contribution gives an overview updating developments of small-molecule, nonpeptide ligands at a selection of peptide and chemokine receptors, expressed in neurons and microglia of the brain, regarding the last five years. Orexin 1 and orexin 2 receptors (OX1R;OX2R) and neuropeptide Y1 and Y2 receptors (NPY1R, NPY2R) were chosen as representatives of Class A neuropeptide receptors, chemokine receptor CX3C (CX3CR1) as Class A, protein-activated receptor, highly expressed in activated microglia, and corticotropin releasing factor receptor 1 (CRFR1) as representative Class B1 receptor. Structural differences between binding domains and their endogenous ligands as well as parallel expression in different types of cells and generally low density of these receptors in brain tissue are factors making the search for selective and sensitive ligands more difficult than for classical GPCR receptors. Main progress in ligand development is observed for NPY receptor antagonists and orexin receptor antagonists. For orexin receptors, search for suitable ligands can be supported with modelling approaches, as recently the complete molecular structure of these receptors is available. Small molecules, binding at CRFR1, as for other Class B1 receptor ligands, in PET and investigations of pharmacodynamics revealed rather allosteric binding modes, although, the complete crystal structure of CRFR1 as prototype of Class B1 provides, hitherto, improved possibilities for understanding binding mechanisms. Highly specific as a marker of microglia among?the GPCRs, CX3CR1 is focused as target of PET during inflammation of brain and spinal cord. 展开更多
关键词 POSITRON Emisson Tomography BRAIN small-molecule Ligand Peptide RECEPTORS Neuron MICROGLIA
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Drilling-based measuring method for the c-φ parameter of rock and its field application 被引量:3
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作者 Bei Jiang Fenglin Ma +5 位作者 Qi Wang Hongke Gao Dahu Zhai Yusong Deng Chuanjie Xu Liangdi Yao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期65-76,共12页
The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R... The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters. 展开更多
关键词 Digital drilling Rock crushing zone c-u parameter Measurement method Field application
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A comparison study on structure-function relationship of polysaccharides obtained from sea buckthorn berries using different methods:antioxidant and bile acid-binding capacity 被引量:5
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作者 Qiaoyun Li Zuman Dou +5 位作者 Qingfei Duan Chun Chen Ruihai Liu Yueming Jiang Bao Yang Xiong Fu 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期494-505,共12页
In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic... In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods. 展开更多
关键词 Sea buckthorn Extraction method STRUCTURE Rheological properties Antioxidant activity Bile acid binding capacity
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Material point method simulation of hydro-mechanical behaviour in twophase porous geomaterials: A state-of-the-art review 被引量:2
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作者 Xiangcou Zheng Shuying Wang +1 位作者 Feng Yang Junsheng Yang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2341-2350,共10页
The material point method(MPM)has been gaining increasing popularity as an appropriate approach to the solution of coupled hydro-mechanical problems involving large deformation.In this paper,we survey the current stat... The material point method(MPM)has been gaining increasing popularity as an appropriate approach to the solution of coupled hydro-mechanical problems involving large deformation.In this paper,we survey the current state-of-the-art in the MPM simulation of hydro-mechanical behaviour in two-phase porous geomaterials.The review covers the recent advances and developments in the MPM and their extensions to capture the coupled hydro-mechanical problems involving large deformations.The focus of this review is aiming at providing a clear picture of what has or has not been developed or implemented for simulating two-phase coupled large deformation problems,which will provide some direct reference for both practitioners and researchers. 展开更多
关键词 Coupled problems Hydro-mechanical behaviour Large deformation Material Point method(MPM)
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Deciphering gastric inflammation-induced tumorigenesis through multi-omics data and AI methods 被引量:1
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作者 Qian Zhang Mingran Yang +3 位作者 Peng Zhang Bowen Wu Xiaosen Wei Shao Li 《Cancer Biology & Medicine》 SCIE CAS CSCD 2024年第4期312-330,共19页
Gastric cancer(GC), the fifth most common cancer globally, remains the leading cause of cancer deaths worldwide. Inflammation-induced tumorigenesis is the predominant process in GC development;therefore, systematic re... Gastric cancer(GC), the fifth most common cancer globally, remains the leading cause of cancer deaths worldwide. Inflammation-induced tumorigenesis is the predominant process in GC development;therefore, systematic research in this area should improve understanding of the biological mechanisms that initiate GC development and promote cancer hallmarks. Here, we summarize biological knowledge regarding gastric inflammation-induced tumorigenesis, and characterize the multi-omics data and systems biology methods for investigating GC development. Of note, we highlight pioneering studies in multi-omics data and state-of-the-art network-based algorithms used for dissecting the features of gastric inflammation-induced tumorigenesis, and we propose translational applications in early GC warning biomarkers and precise treatment strategies. This review offers integrative insights for GC research, with the goal of paving the way to novel paradigms for GC precision oncology and prevention. 展开更多
关键词 Gastric cancer inflammation-induced tumorigenesis multi-omics artificial intelligence network-based methods
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Volumetric lattice Boltzmann method for pore-scale mass diffusionadvection process in geopolymer porous structures 被引量:1
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作者 Xiaoyu Zhang Zirui Mao +6 位作者 Floyd W.Hilty Yulan Li Agnes Grandjean Robert Montgomery Hans-Conrad zur Loye Huidan Yu Shenyang Hu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2126-2136,共11页
Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advecti... Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material design.In this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous structures.These structures are created using the phase field method(PFM)to precisely control pore architectures.In our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population function.To address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(GPU)parallelization.Validation of the developed model involves examining the flow and diffusion fields in porous structures.Remarkably,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,respectively.Notably,all three parameters exert an influence on the diffusion-advection process.Increased background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,respectively.Conversely,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore volume.This comprehensive parametric study provides valuable insights into the kinetics of isotope uptake in porous structures,facilitating the development of porous materials for nuclear waste treatment applications. 展开更多
关键词 Volumetric lattice Boltzmann method(VLBM) Phase field method(PFM) Pore-scale diffusion-advection Nuclear waste treatment Porous media flow Graphics processing unit(GPU) parallelization
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Uncertainties of landslide susceptibility prediction: Influences of random errors in landslide conditioning factors and errors reduction by low pass filter method 被引量:2
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作者 Faming Huang Zuokui Teng +4 位作者 Chi Yao Shui-Hua Jiang Filippo Catani Wei Chen Jinsong Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期213-230,共18页
In the existing landslide susceptibility prediction(LSP)models,the influences of random errors in landslide conditioning factors on LSP are not considered,instead the original conditioning factors are directly taken a... In the existing landslide susceptibility prediction(LSP)models,the influences of random errors in landslide conditioning factors on LSP are not considered,instead the original conditioning factors are directly taken as the model inputs,which brings uncertainties to LSP results.This study aims to reveal the influence rules of the different proportional random errors in conditioning factors on the LSP un-certainties,and further explore a method which can effectively reduce the random errors in conditioning factors.The original conditioning factors are firstly used to construct original factors-based LSP models,and then different random errors of 5%,10%,15% and 20%are added to these original factors for con-structing relevant errors-based LSP models.Secondly,low-pass filter-based LSP models are constructed by eliminating the random errors using low-pass filter method.Thirdly,the Ruijin County of China with 370 landslides and 16 conditioning factors are used as study case.Three typical machine learning models,i.e.multilayer perceptron(MLP),support vector machine(SVM)and random forest(RF),are selected as LSP models.Finally,the LSP uncertainties are discussed and results show that:(1)The low-pass filter can effectively reduce the random errors in conditioning factors to decrease the LSP uncertainties.(2)With the proportions of random errors increasing from 5%to 20%,the LSP uncertainty increases continuously.(3)The original factors-based models are feasible for LSP in the absence of more accurate conditioning factors.(4)The influence degrees of two uncertainty issues,machine learning models and different proportions of random errors,on the LSP modeling are large and basically the same.(5)The Shapley values effectively explain the internal mechanism of machine learning model predicting landslide sus-ceptibility.In conclusion,greater proportion of random errors in conditioning factors results in higher LSP uncertainty,and low-pass filter can effectively reduce these random errors. 展开更多
关键词 Landslide susceptibility prediction Conditioning factor errors Low-pass filter method Machine learning models Interpretability analysis
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Sparse Modal Decomposition Method Addressing Underdetermined Vortex-Induced Vibration Reconstruction Problem for Marine Risers 被引量:1
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作者 DU Zun-feng ZHU Hai-ming YU Jian-xing 《China Ocean Engineering》 SCIE EI CSCD 2024年第2期285-296,共12页
When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fa... When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real risers.The problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration modes.However,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known measurements.This study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal space.In the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring. 展开更多
关键词 motion reconstruction vortex-induced vibration(VIV) marine riser modal decomposition method compressed sensing
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Numerical manifold method for thermo-mechanical coupling simulation of fractured rock mass 被引量:1
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作者 Jiawei Liang Defu Tong +3 位作者 Fei Tan Xiongwei Yi Junpeng Zou Jiahe Lv 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期1977-1992,共16页
As a calculation method based on the Galerkin variation,the numerical manifold method(NMM)adopts a double covering system,which can easily deal with discontinuous deformation problems and has a high calculation accura... As a calculation method based on the Galerkin variation,the numerical manifold method(NMM)adopts a double covering system,which can easily deal with discontinuous deformation problems and has a high calculation accuracy.Aiming at the thermo-mechanical(TM)coupling problem of fractured rock masses,this study uses the NMM to simulate the processes of crack initiation and propagation in a rock mass under the influence of temperature field,deduces related system equations,and proposes a penalty function method to deal with boundary conditions.Numerical examples are employed to confirm the effectiveness and high accuracy of this method.By the thermal stress analysis of a thick-walled cylinder(TWC),the simulation of cracking in the TWC under heating and cooling conditions,and the simulation of thermal cracking of the SwedishÄspöPillar Stability Experiment(APSE)rock column,the thermal stress,and TM coupling are obtained.The numerical simulation results are in good agreement with the test data and other numerical results,thus verifying the effectiveness of the NMM in dealing with thermal stress and crack propagation problems of fractured rock masses. 展开更多
关键词 Heat conduction Fractured rock mass Crack propagation Galerkin variation Numerical manifold method(NMM)
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A stable implicit nodal integration-based particle finite element method(N-PFEM)for modelling saturated soil dynamics 被引量:1
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作者 Liang Wang Xue Zhang +1 位作者 Jingjing Meng Qinghua Lei 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2172-2183,共12页
In this study,we present a novel nodal integration-based particle finite element method(N-PFEM)designed for the dynamic analysis of saturated soils.Our approach incorporates the nodal integration technique into a gene... In this study,we present a novel nodal integration-based particle finite element method(N-PFEM)designed for the dynamic analysis of saturated soils.Our approach incorporates the nodal integration technique into a generalised Hellinger-Reissner(HR)variational principle,creating an implicit PFEM formulation.To mitigate the volumetric locking issue in low-order elements,we employ a node-based strain smoothing technique.By discretising field variables at the centre of smoothing cells,we achieve nodal integration over cells,eliminating the need for sophisticated mapping operations after re-meshing in the PFEM.We express the discretised governing equations as a min-max optimisation problem,which is further reformulated as a standard second-order cone programming(SOCP)problem.Stresses,pore water pressure,and displacements are simultaneously determined using the advanced primal-dual interior point method.Consequently,our numerical model offers improved accuracy for stresses and pore water pressure compared to the displacement-based PFEM formulation.Numerical experiments demonstrate that the N-PFEM efficiently captures both transient and long-term hydro-mechanical behaviour of saturated soils with high accuracy,obviating the need for stabilisation or regularisation techniques commonly employed in other nodal integration-based PFEM approaches.This work holds significant implications for the development of robust and accurate numerical tools for studying saturated soil dynamics. 展开更多
关键词 Particle finite element method Nodal integration Dynamic saturated media Second-order cone programming(SOCP)
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An inverse analysis of fluid flow through granular media using differentiable lattice Boltzmann method 被引量:1
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作者 Qiuyu Wang Krishna Kumar 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2077-2090,共14页
This study presents a method for the inverse analysis of fluid flow problems.The focus is put on accurately determining boundary conditions and characterizing the physical properties of granular media,such as permeabi... This study presents a method for the inverse analysis of fluid flow problems.The focus is put on accurately determining boundary conditions and characterizing the physical properties of granular media,such as permeability,and fluid components,like viscosity.The primary aim is to deduce either constant pressure head or pressure profiles,given the known velocity field at a steady-state flow through a conduit containing obstacles,including walls,spheres,and grains.The lattice Boltzmann method(LBM)combined with automatic differentiation(AD)(AD-LBM)is employed,with the help of the GPU-capable Taichi programming language.A lightweight tape is used to generate gradients for the entire LBM simulation,enabling end-to-end backpropagation.Our AD-LBM approach accurately estimates the boundary conditions for complex flow paths in porous media,leading to observed steady-state velocity fields and deriving macro-scale permeability and fluid viscosity.The method demonstrates significant advantages in terms of prediction accuracy and computational efficiency,making it a powerful tool for solving inverse fluid flow problems in various applications. 展开更多
关键词 Inverse problem Fluid flow Granular media Automatic differentiation(AD) Lattice Boltzmann method(LBM)
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Robustness Study and Superior Method Development and Validation for Analytical Assay Method of Atropine Sulfate in Pharmaceutical Ophthalmic Solution
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作者 Md. Nazmus Sakib Chowdhury Sreekanta Nath Dalal +4 位作者 Md. Ariful Islam Md. Anwar Hossain Pranab Kumar Das Shakawat Hossain Parajit Das 《American Journal of Analytical Chemistry》 CAS 2024年第5期151-164,共14页
Background: The robustness is a measurement of an analytical chemical method and its ability to contain unaffected by little with deliberate variation of analytical chemical method parameters. The analytical chemical ... Background: The robustness is a measurement of an analytical chemical method and its ability to contain unaffected by little with deliberate variation of analytical chemical method parameters. The analytical chemical method variation parameters are based on pH variability of buffer solution of mobile phase, organic ratio composition changes, stationary phase (column) manufacture, brand name and lot number variation;flow rate variation and temperature variation of chromatographic system. The analytical chemical method for assay of Atropine Sulfate conducted for robustness evaluation. The typical variation considered for mobile phase organic ratio change, change of pH, change of temperature, change of flow rate, change of column etc. Purpose: The aim of this study is to develop a cost effective, short run time and robust analytical chemical method for the assay quantification of Atropine in Pharmaceutical Ophthalmic Solution. This will help to make analytical decisions quickly for research and development scientists as well as will help with quality control product release for patient consumption. This analytical method will help to meet the market demand through quick quality control test of Atropine Ophthalmic Solution and it is very easy for maintaining (GDP) good documentation practices within the shortest period of time. Method: HPLC method has been selected for developing superior method to Compendial method. Both the compendial HPLC method and developed HPLC method was run into the same HPLC system to prove the superiority of developed method. Sensitivity, precision, reproducibility, accuracy parameters were considered for superiority of method. Mobile phase ratio change, pH of buffer solution, change of stationary phase temperature, change of flow rate and change of column were taken into consideration for robustness study of the developed method. Results: The limit of quantitation (LOQ) of developed method was much low than the compendial method. The % RSD for the six sample assay of developed method was 0.4% where the % RSD of the compendial method was 1.2%. The reproducibility between two analysts was 100.4% for developed method on the contrary the compendial method was 98.4%. 展开更多
关键词 ROBUSTNESS method Validation HPLC Compendial method method Development GDP LOQ
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Cascading multi-segment rupture process of the 2023 Turkish earthquake doublet on a complex fault system revealed by teleseismic P wave back projection method 被引量:1
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作者 Bonan Cao Zengxi Ge 《Earthquake Science》 2024年第2期158-173,共16页
In this study,the vertical components of broadband teleseismic P wave data recorded by China Earthquake Network are used to image the rupture processes of the February 6th,2023 Turkish earthquake doublet via back proj... In this study,the vertical components of broadband teleseismic P wave data recorded by China Earthquake Network are used to image the rupture processes of the February 6th,2023 Turkish earthquake doublet via back projection analysis.Data in two frequency bands(0.5-2 Hz and 1-3 Hz)are used in the imaging processes.The results show that the rupture of the first event extends about 200 km to the northeast and about 150 km to the southwest,lasting~90 s in total.The southwestern rupture is triggered by the northeastern rupture,demonstrating a sequential bidirectional unilateral rupture pattern.The rupture of the second event extends approximately 80 km in both northeast and west directions,lasting~35 s in total and demonstrates a typical bilateral rupture feature.The cascading ruptures on both sides also reflect the occurrence of selective rupture behaviors on bifurcated faults.In addition,we observe super-shear ruptures on certain fault sections with relatively straight fault structures and sparse aftershocks. 展开更多
关键词 2023 Turkish earthquake doublet back projection method cascading segmented rupture process coseismic triggering super-shear ruptures
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Hybrid Strategy of Partitioned and Monolithic Methods for Solving Strongly Coupled Analysis of Inverse and Direct Piezoelectric and Circuit Coupling
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作者 Daisuke Ishihara Syunnosuke Nozaki +1 位作者 Tomoya Niho Naoto Takayama 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1371-1386,共16页
The inverse and direct piezoelectric and circuit coupling are widely observed in advanced electro-mechanical systems such as piezoelectric energy harvesters.Existing strongly coupled analysis methods based on direct n... The inverse and direct piezoelectric and circuit coupling are widely observed in advanced electro-mechanical systems such as piezoelectric energy harvesters.Existing strongly coupled analysis methods based on direct numerical modeling for this phenomenon can be classified into partitioned or monolithic formulations.Each formulation has its advantages and disadvantages,and the choice depends on the characteristics of each coupled problem.This study proposes a new option:a coupled analysis strategy that combines the best features of the existing formulations,namely,the hybrid partitioned-monolithic method.The analysis of inverse piezoelectricity and the monolithic analysis of direct piezoelectric and circuit interaction are strongly coupled using a partitioned iterative hierarchical algorithm.In a typical benchmark problem of a piezoelectric energy harvester,this research compares the results from the proposed method to those from the conventional strongly coupled partitioned iterative method,discussing the accuracy,stability,and computational cost.The proposed hybrid concept is effective for coupled multi-physics problems,including various coupling conditions. 展开更多
关键词 Structure-piezoelectric-circuit interaction energy harvesting partitioned method monolithic method hybrid method
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