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Influence of initial curing conditions and exposure environments on chloride migration in concrete using

Wen XUE, Weiliang JIN, Hiroshi YOKOTA,

《结构与土木工程前沿(英文)》 2010年 第4卷 第3期   页码 348-353 doi: 10.1007/s11709-010-0077-3

摘要: To investigate the influence of initial curing conditions and exposure environments on chloride ions’ migration in concrete, the specimens that were cured in different conditions and placed in several marine environments were studied. The amount of chloride ions passing through the specimen’s section was monitored in the accelerated chloride migration test. The effective chloride diffusion coefficients () were calculated from the steady-state on the basis of Nernst-Planck’s equation. The results indicated that the initial curing conditions and the wet-dry interval of external environments have coupling influence on effective diffusion coefficient of chloride ion significantly. reflected the density and pore connectivity of concrete. The co-effects of the initial curing condition and following exposure environment should be taken into account in durability design for concrete structure located in marine environment.

关键词: durability     effective diffusion coefficient     steady-state     migration test    

Theoretical study on the mechanism of sulfur migration to gas in the pyrolysis of benzothiophene

《化学科学与工程前沿(英文)》 2023年 第17卷 第3期   页码 334-346 doi: 10.1007/s11705-022-2209-4

摘要: The release and control of sulfur species in the pyrolysis of fossil fuels and solid wastes have attracted attention worldwide. Particularly, thiophene derivatives are important intermediates for the sulfur gas release from organic sulfur, but the underlying migration mechanisms remain unclear. Herein, the mechanism of sulfur migration during the release of sulfur-containing radicals in benzothiophene pyrolysis was explored through quantum chemistry modeling. The C1-to-C2 H-transfer has the lowest energy barrier of 269.9 kJ·mol–1 and the highest rate constant at low temperatures, while the elevated temperature is beneficial for C−S bond homolysis. 2-Ethynylbenzenethiol is the key intermediate for the formation of S and SH radicals with the overall energy barriers of 408.0 and 498.7 kJ·mol–1 in favorable pathways. The generation of CS radicals is relatively difficult because of the high energy barrier (551.8 kJ·mol–1). However, it can be significantly promoted by high temperatures, where the rate constant exceeds that for S radical generation above 930 °C. Consequently, the strong competitiveness of S and SH radicals results in abundant H2S during benzothiophene pyrolysis, and the high temperature is more beneficial for CS2 generation from CS radicals. This study lays a foundation for elucidating sulfur migration mechanisms and furthering the development of pyrolysis techniques.

关键词: benzothiophene     sulfur migration     pyrolysis     density functional theory    

Regulatory factors of mesenchymal stem cell migration into injured tissues and their signal transduction

null

《医学前沿(英文)》 2011年 第5卷 第1期   页码 33-39 doi: 10.1007/s11684-011-0114-1

摘要:

Adult stem cells hold great promise for wound healing and tissue regeneration. Mesenchymal stem cells (MSCs), for example, have been shown to play a role in tissue repair. Research has shown that endogenous bone marrow MSCs or exogenously delivered MSCs migrate to the sites of injury and participate in the repair process. The precise mechanisms underlying migration of MSCs into the injured tissue are still not fully understood, although multiple signaling pathways and molecules were reported, including both chemoattractive factors and endogenous electric fields at wounds. This review will briefly summarize the regulatory facors and signaling transduction pathways involved in migration of MSCs. A better understanding of the molecular mechanisms involved in the migration of MSCs will help us to develop new stem cell-based therapeutic strategies in regenerative medicine.

关键词: mesenchymal stem cells     migration     molecular mechanisms     signaling pathway    

Effects of sucrose crystallization and moisture migration on the structural changes of a coated intermediate

Tiancheng LI, Peng ZHOU, Theodore P. LABUZA

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 346-350 doi: 10.1007/s11705-009-0256-8

摘要: The purpose of this study was to investigate whether moisture migration and sugar crystallization play an important role in the changes of IMF matrix structure. The migration of water was monitored with changes of water activity in different physical domains of samples during storage, while the crystallization of sucrose was determined with X-ray powder diffraction (XRD). The formation of both a hard inner-layer and agglomerated particles in the inner matrix was observed during storage. Our results suggested that both moisture loss and sucrose crystallization were mainly responsible for the formation of the crusty intermediate inner layer, and the agglomerated matrix particles were the result of sucrose crystallization.

关键词: inner-layer     agglomerated     IMF     moisture migration     crystallization    

Disabled homolog 2 is required for migration and invasion of prostate cancer cells

null

《医学前沿(英文)》 2015年 第9卷 第3期   页码 312-321 doi: 10.1007/s11684-015-0401-3

摘要:

Disabled homolog 2 (DAB2) is frequently deleted or epigenetically silenced in many human cancer cells. Therefore, DAB2 has always been regarded as a tumor suppressor gene. However, the role of DAB2 in tumor progression and metastasis remains unclear. In this study, DAB2 expression was upregulated along with human prostate cancer (PCa) progression. DAB2overexpression or knockdown effects in LNCaP and PC3 cell lines were verified to address the biological functions of DAB2 in PCa progression and metastasis. LNCaP and PC3 cell lines were generated from human PCa cells with low and high metastatic potentials, respectively. The results showed that DAB2 shRNA knockdown can inhibit the migratory and invasive abilities of PC3 cells, as well as the tumorigenicity, whereas DAB2 overexpression enhanced LNCaP cell migration and invasion. Further investigation showed that DAB2 regulated the cell migration associated genes in PC3 cells, and the differential DAB2 expression between LNCaP and PC3 cells was partly regulated by histone 4 acetylation. Therefore, DAB2 may play an important role in PCa progression and metastasis.

关键词: DAB2     prostate cancer     migration     invasion     acetylation    

Fighting for the poverty: a case study for human migration in the context of sustainable dryland farming

Yongqing MA, Jie CHEN, Shuqi DONG, Lun SHAN

《农业科学与工程前沿(英文)》 2014年 第1卷 第1期   页码 62-68 doi: 10.15302/J-FASE-2014027

摘要: The Southern Ningxia Hilly Area is one of the most impoverished areas of Ningxia Hui Autonomous Region (a province) of China due to an economy that mainly relies on agriculture, which is affected by droughts in two out of every three years. Government programs have attempted to develop an increased and sustainable level of scientifically based agricultural production while restoring the environment. However, since the population exceeds the capacity of the land to adequately support it, a program is underway to move 350000 people to more suitable locations. This paper outlines the past improvements to the Southern Ningxia Hilly Area and considers future development in the context of migration for ecological reasons.

关键词: agricultural production     animal husbandry     development strategy     ecological migration    

Effects of miR-200c on the migration and invasion abilities of human prostate cancer Du145 cells and

null

《医学前沿(英文)》 2014年 第8卷 第4期   页码 456-463 doi: 10.1007/s11684-014-0353-z

摘要:

microRNAs (miRNAs) have played a key role in human tumorigenesis, tumor progression, and metastasis. On the one hand, miRNAs are aberrantly expressed in many types of human cancer; on the other hand, miRNAs can function as tumor suppressors or oncogenes that target many cancer-related genes. This study aimed to investigate the effects of miRNA-200c (miR-200c) on the biological behavior and mechanism of proliferation, migration, and invasion in the prostate cancer cell line Du145. In this study, Du145 cells were transfected with miR-200c mimics or negative control miR-NC by using an X-tremeGENE siRNA transfection reagent. The relative expression of miR-200c was measured by RT-PCR. The proliferation, migration, and invasion abilities of Du145 cells were detected by CCK8 assays, migration assays and invasion assays, respectively. The expressions of ZEB1, E-cadherin, and vimentin were observed by western blot. Results showed that DU145 cells exhibited a high expression of miR-200c compared with immortalized normal prostate epithelial cell RWPE-1. Du145 cells were then transfected with miR-200c mimics and displayed lower abilities of proliferation, migration, and invasion than those transfected with the negative control. The protein levels of ZEB1 and vimentin were expressed at a low extent in Du145 cells, which were transfected with miR-200c mimics; by contrast, E-cadherin was highly expressed. Hence, miR-200c could significantly inhibit the proliferation of the prostate cancer cell line Du145; likewise, miR-200c could inhibit migration and invasion by epithelial-mesenchymal transition.

关键词: miR-200c     proliferation     migration     invasion     prostate cancer     Du145 cell     ZEB1    

A microarray study of altered gene expression during melanoblasts migration in normal pigmented White

Yulin LI,Deping HAN,Junying LI,Dawn KOLTES,Xuemei DENG

《农业科学与工程前沿(英文)》 2014年 第1卷 第4期   页码 299-306 doi: 10.15302/J-FASE-2014040

摘要: Melanoblasts originating from neural crest cells can migrate through the mesenchyme of the developed embryo and give rise to melanocytes. Unlike the melanocytes that are confined to the integument in other vertebrates, melanocytes in Silky Fowl can reach the ventral regions of the embryos owing to differences in gene expression in the process of melanoblasts migration. In this study, we used microarray profiling to identify differences in gene expression between White Leghorn and Silky Fowl. Differential expression of 2517 microarray probes ( <0.01, Fold Change>2) was observed in Silky Fowl compared to White Leghorn. After filtration by cluster analysis, functional annotation and pathway analysis, eight differentially expressed genes were identified to be closely related to the development of melanocytes. Moreover, differences in expression of immune genes were also detected between Silky Fowl and White Leghorn. The differentially expressed genes associated with melanocyte development were verified by q-PCR, and results were highly consistent with the microarray data. The genes with significantly altered expression involved in melanoblast migration and development suggested that different microenvironments resulted in the abnormal melanoblast migration in Silky Fowl, although there were no big differences in melanoblast development between these two breeds. The candidate genes discovered in this study are beneficial to understand the molecular mechanism of hyperpigmentation in Silky Fowl.

关键词: Silky Fowl     White Leghorn     melanoblast migration     gene expression    

Migration and fate of polycyclic aromatic hydrocarbons in bioretention systems with different media:

《环境科学与工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1802-9

摘要:

● Bioretention systems showed > 92% load reduction rates of PAHs.

关键词: Bioretention     Polycyclic aromatic hydrocarbons     HYDRUS-1D     Model simulation     Migration    

Influence of the intensity and loading time of direct current electric field on the directional migration

null

《医学前沿(英文)》 2016年 第10卷 第3期   页码 286-296 doi: 10.1007/s11684-016-0456-9

摘要:

Exogenic electric fields can effectively accelerate bone healing and remodeling through the enhanced migration of bone marrow mesenchymal stem cells (BMSCs) toward the injured area. This study aimed to determine the following: (1) the direction of rat BMSC (rBMSC) migration upon exposure to a direct current electric field (DCEF), (2) the optimal DCEF intensity and duration, and (3) the possible regulatory role of SDF-1/CXCR4 axis in rBMSC migration as induced by DCEF. Results showed that rBMSCs migrated to the positive electrode of the DCEF, and that the DCEF of 200 mV/mm for 4 h was found to be optimal in enhancing rBMSC migration. This DCEF strength and duration also upregulated the expression of osteoblastic genes, including ALP and OCN, and upregulated the expression of ALP and Runx2 proteins. Moreover, when CXCR4 was inhibited, rBMSC migration due to DCEF was partially blocked. These findings indicated that DCEF can effectively induce rBMSC migration. A DCEF of 200 mV/mm for 4 h was recommended because of its ability to promote rBMSC migration, proliferation, and osteogenic differentiation. The SDF-1/CXCR4 signaling pathway may play an important role in regulating the DCEF-induced migration of rBMSCs.

关键词: DCEF     migration     osteogenesis differentiation     rBMSCs     SDF-1/CXCR-4    

Occurrence and migration of microplastics and plasticizers in different wastewater and sludge treatment

《环境科学与工程前沿(英文)》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1577-9

摘要:

● Reduce the quantifying MPs time by using Nile red staining.

关键词: Microplastics     Municipal wastewater treatment plant     Phthalate esters     Thermal hydrolysis    

Assessment of future climate change impacts on water-heat-salt migration in unsaturated frozen soil using

Hanli Wan, Jianmin Bian, Han Zhang, Yihan Li

《环境科学与工程前沿(英文)》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1302-5

摘要: Abstract • A model coupling water-heat-salt of unsaturated frozen soil was established. • Future temperature, precipitation, and evaporation increase in freeze–thaw period. • Soil water, heat, and salt transport are closely coupled during freeze–thaw period. • Freeze–thaw cycles and future climate change can exacerbate salinization. The transport mechanisms of water, heat, and salt in unsaturated frozen soil, as well as its response to future climate change are in urgent need of study. In this study, western Jilin Province in north-eastern China was studied to produce a model of coupled water-heat-salt in unsaturated frozen soil using CoupModel. The water, heat, and salt dynamics of unsaturated frozen soil under three representative concentration pathway (RCP) scenarios were simulated to analyze the effects of future climate change on unsaturated frozen soil. The results show that water, heat, and salt migration are tightly coupled, and the soil salt concentration in the surface layer (10 cm) exhibits explosive growth after freezing and thawing. The future (2020–2099) meteorological factors in the study area were predicted using the Statistical Downscaling Model (SDSM). For RCP2.6, RCP4.5, and RCP8.5 scenarios, future temperatures during the freeze–thaw period increased by 2.68°C, 3.18°C, and 4.28°C, respectively; precipitation increased by 30.28 mm, 28.41 mm, and 32.17 mm, respectively; and evaporation increased by 93.57 mm, 106.95 mm, and 130.57 mm, respectively. Climate change will shorten the freeze–thaw period, advance the soil melting time from April to March, and enhance water and salt transport. Compared to the baseline period (1961–2005), future soil salt concentrations at 10 cm increased by 1547.54 mg/L, 1762.86 mg/L, and 1713.66 mg/L under RCP2.6, RCP4.5, and RCP8.5, respectively. The explosive salt accumulation is more obvious. Effective measures should be taken to prevent the salinization of unsaturated frozen soils and address climate change.

关键词: Soil salinization     Climate change     Unsaturated frozen soil     Water-heat-salt balance     Soil environment change    

复杂环境下起伏地形探地雷达逆时偏移成像 Article

John H. Bradford,Janna Privette,David Wilkins,Richard Ford

《工程(英文)》 2018年 第4卷 第5期   页码 661-666 doi: 10.1016/j.eng.2018.09.004

摘要: 为了优化成像效果,本文提出了一种基于麦克斯韦方程组二阶解耦形式的逆时偏移成像(reversetime migration,RTM)算法,该算法特点在于只需计算电场,且可直接从采集面而非基准面进行波场延拓

关键词: 探地雷达     逆时偏移     沙丘     振幅分析    

Mechanical performance analysis and stiffness test of a new type of suspension bridge

《结构与土木工程前沿(英文)》 2021年 第15卷 第5期   页码 1160-1180 doi: 10.1007/s11709-021-0760-6

摘要: A new type of suspension bridge is proposed based on the gravity stiffness principle. Compared with a conventional suspension bridge, the proposed bridge adds rigid webs and cross braces. The rigid webs connect the main cable and main girder to form a truss that can improve the bending stiffness of the bridge. The cross braces connect the main cables to form a closed space truss structure that can improve the torsional stiffness of the bridge. The rigid webs and cross braces are installed after the construction of a conventional suspension bridge is completed to resist different loads with different structural forms. A new type of railway suspension bridge with a span of 340 m and a highway suspension bridge with a span of 1020 m were designed and analysed using the finite element method. The stress, deflection of the girders, unbalanced forces of the main towers, and natural frequencies were compared with those of conventional suspension bridges. A stiffness test was carried out on the new type of suspension bridge with a small span, and the results were compared with those for a conventional bridge. The results showed that the new suspension bridge had a better performance than the conventional suspension bridge.

关键词: new type of suspension bridge     stiffness test     mechanical performance     railway bridge     space truss    

Mixed mode properties of CNT reinforced composites using Arcan test rig

Jacob MUTHU

《结构与土木工程前沿(英文)》 2015年 第9卷 第4期   页码 397-404 doi: 10.1007/s11709-015-0321-y

摘要: Composite materials reinforced with carbon nanotubes were mechanical tested using Arcan test rig under Mode-I, Mode-II and mixed mode loading conditions to obtain their fracture properties. The butterfly composite specimens were fabricated with 0.02, 0.05 and 0.1 wt % CNTs. The polyester/CNT composite was fabricated using VRTM (Vacuum Resin Transfer Molding) where the CNTs were first functionalised to reach an optimum properties. Arcan test rig was designed and fabricated to work with the Shimadzu testing machine. The results show that the functionalised CNTs have improved the fracture behavior by acting as bridge between the cracked face. In addition, the fracture properties were not improved for the higher weight fraction of 0.1 wt% CNTs.

关键词: CNT     composites     Arcan test rig     stress intensity factor    

标题 作者 时间 类型 操作

Influence of initial curing conditions and exposure environments on chloride migration in concrete using

Wen XUE, Weiliang JIN, Hiroshi YOKOTA,

期刊论文

Theoretical study on the mechanism of sulfur migration to gas in the pyrolysis of benzothiophene

期刊论文

Regulatory factors of mesenchymal stem cell migration into injured tissues and their signal transduction

null

期刊论文

Effects of sucrose crystallization and moisture migration on the structural changes of a coated intermediate

Tiancheng LI, Peng ZHOU, Theodore P. LABUZA

期刊论文

Disabled homolog 2 is required for migration and invasion of prostate cancer cells

null

期刊论文

Fighting for the poverty: a case study for human migration in the context of sustainable dryland farming

Yongqing MA, Jie CHEN, Shuqi DONG, Lun SHAN

期刊论文

Effects of miR-200c on the migration and invasion abilities of human prostate cancer Du145 cells and

null

期刊论文

A microarray study of altered gene expression during melanoblasts migration in normal pigmented White

Yulin LI,Deping HAN,Junying LI,Dawn KOLTES,Xuemei DENG

期刊论文

Migration and fate of polycyclic aromatic hydrocarbons in bioretention systems with different media:

期刊论文

Influence of the intensity and loading time of direct current electric field on the directional migration

null

期刊论文

Occurrence and migration of microplastics and plasticizers in different wastewater and sludge treatment

期刊论文

Assessment of future climate change impacts on water-heat-salt migration in unsaturated frozen soil using

Hanli Wan, Jianmin Bian, Han Zhang, Yihan Li

期刊论文

复杂环境下起伏地形探地雷达逆时偏移成像

John H. Bradford,Janna Privette,David Wilkins,Richard Ford

期刊论文

Mechanical performance analysis and stiffness test of a new type of suspension bridge

期刊论文

Mixed mode properties of CNT reinforced composites using Arcan test rig

Jacob MUTHU

期刊论文