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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    

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amino-functionalized University of Oslo 66 membranes as efficacious polysulfide barriers for lithium−sulfur

《化学科学与工程前沿（英文）》 2023年 第17卷 第2期   页码 194-205 doi: 10.1007/s11705-022-2206-7

摘要： The shuttle effect of soluble polysulfides is a serious problem impeding the development of lithium−sulfur batteries. Herein, continuous amino-functionalized University of Oslo 66 membranes supported on carbon nanotube films are proposed as ion-permselective interlayers that overcome these issues and show outstanding suppression of the polysulfide shuttle effect. The proposed membrane material has appropriately sized pores, and can act as ionic sieves and serve as barriers to polysulfides transport while allowing the passage of lithium ions during electrochemical cycles, thereby validly preventing the shuttling of polysulfides. Moreover, a fast catalytic conversion of polysulfides is also achieved with the as-developed interlayer. Therefore, lithium−sulfur batteries with this interlayer show a desirable initial capacity of 999.21 mAh·g–1 at 1 C and a durable cyclic stability with a decay rate of only 0.04% per cycle over 300 cycles. Moreover, a high area capacity of 4.82 mAh·cm–2 is also obtained even under increased sulfur loading (5.12 mg·cm–2) and a lean-electrolyte condition (E/S = 4.8 μL·mg–1).

关键词： lithium−sulfur batteries     amino-functionalized University of Oslo 66 membrane     polysulfide     interlayer    

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Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic

《化学科学与工程前沿（英文）》 2023年 第17卷 第1期   页码 93-101 doi: 10.1007/s11705-022-2175-x

摘要： Defect construction and heteroatom doping are effective strategies for improving photocatalytic activity of carbon nitride (g-C3N4). In this work, N defects were successfully prepared via cold plasma. High-energy electrons generated by plasma can produce N defects and embed sulfur atoms into g-C3N4. The N defects obviously promoted photocatalytic degradation performance that was 7.5 times higher than that of pure g-C3N4. The concentration of N defects can be tuned by different power and time of plasma. With the increase in N defects, the photocatalytic activity showed a volcanic trend. The g-C3N4 with moderate concentration of N defects exhibited the highest photocatalytic activity. S-doped g-C3N4 exhibited 11.25 times higher photocatalytic activity than pure g-C3N4. It provided extra active sites for photocatalytic reaction and improved stability of N defects. The N vacancy-enriched and S-doped g-C3N4 are beneficial for widening absorption edge and improving the separation efficiency of electron and holes.

关键词： g-C3N4     nitrogen defect     sulfur doping     photodegradation     plasma    

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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    

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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    

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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    

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Kombucha SCOBY-based carbon and graphene oxide wrapped sulfur/polyacrylonitrile as a high-capacity cathodein lithium-sulfur batteries

Krishnaveni Kalaiappan, Subadevi Rengapillai, Sivakumar Marimuthu, Raja Murugan, Premkumar Thiru

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 976-987 doi: 10.1007/s11705-019-1897-x

摘要： Hierarchically-porous carbon nano sheets were prepared as a conductive additive for sulfur/polyacrylonitrile (S/PAN) composite cathodes using a simple heat treatment. In this study, kombucha (that was derived from symbiotic culture of bacteria and yeast) carbon (KC) and graphene oxide (GO) were used as a carbon host matrix. These rational-designed S/PAN/KC/GO hybrid composites greatly suppress the diffusion of polysulfides by providing strong physical and chemical adsorption. The cathode delivered an initial discharge capacity of 1652 mAh·g at a 0.1 C rate and a 100 cycle capacity of 1193 mAh·g . The nano sheets with embedded hierarchical pores create a conductive network that provide effective electron transfer and fast electrochemical kinetics. Further, the nitrogen component of PAN can raise the affinity/interaction of the carbon host with lithium polysulfides, supporting the cyclic performance. The results exploit the cumulative contribution of both the conductive carbon matrix and PAN in the enhanced performance of the positive electrode.

关键词： sulfur cathode     kombucha SCOBY     graphene oxide     polyacrylonitrile     lithium-sulfur battery    

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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    

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Denitrification performance and sulfur resistance mechanism of Sm–Mn catalyst for low temperature NH-SCR

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 617-633 doi: 10.1007/s11705-022-2258-8

摘要： MnOx and Sm–Mn catalysts were prepared with the coprecipitation method, and they showed excellent activities and sulfur resistances for the selective catalytic reduction of NOx by NH3 between 50 and 300 °C in the presence of excess oxygen. 0.10Sm–Mn catalyst indicated better catalytic activity and sulfur resistance. Additionally, the Sm doping led to multi-aspect impacts on the phases, morphology structures, gas adsorption, reactions process, and specific surface areas. Therefore, it significantly enhances the NO conversion, N2 selectivity, and sulfur resistance. Based on various experimental characterization results, the reaction mechanism of catalysts and the effect of SO2 on the reaction process about the catalysts were extensively explored. For 0.10Sm–Mn catalyst, manganese sulfate and sulfur ammonium cannot be generated broadly under the influence of SO2 and the amount of surface adsorbed oxygen. The Bronsted acid sites strengthen significantly due to the addition of SO2, enhancing the sulfur resistance of the 0.10Sm–Mn catalyst.

关键词： MnOx     Sm–Mn     catalyst     NH3-SCR     sulfur resistance    

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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    

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zirconium-based metal-organic framework-801 films on carbon cloth as shuttle-inhibiting interlayers for lithium-sulfur

《化学科学与工程前沿（英文）》 2022年 第16卷 第4期   页码 511-522 doi: 10.1007/s11705-021-2068-4

摘要： Lithium-sulfur batteries have been regarded as the next-generation rechargeable batteries due to their high theoretical energy density and specific capacity. Nevertheless, the shuttle effect of lithium polysulfides has hindered the development of lithium-sulfur batteries. Herein, a novel zirconium-based metal-organic framework-801 film on carbon cloth was developed as a versatile interlayer for lithium-sulfur batteries. This interlayer has a hierarchical porous structure, suitable for the immobilization of lithium polysulfides and accommodating volume expansion on cycling. Moreover, the MOF-801 material is capable of strongly adsorbing lithium polysulfides and promoting their catalytic conversion, which can be enhanced by the abundant active sites provided by the continuous structure of the MOF-801 films. Based on the above advantages, the lithium-sulfur battery, with the proposed interlayer, delivers an initial discharge capacity of 927 mAh·g–1 at 1 C with an extremely low decay rate of 0.04% over 500 cycles. Additionally, a high area capacity of 4.3 mAh·cm–2 can be achieved under increased S loading.

关键词： lithium-sulfur batteries     metal-organic framework-801 film     interlayer     shuttle effect    

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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    

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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    

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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    

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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    

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标题 作者 时间 类型 操作

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

期刊论文

amino-functionalized University of Oslo 66 membranes as efficacious polysulfide barriers for lithium−sulfur

期刊论文

Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic

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

Kombucha SCOBY-based carbon and graphene oxide wrapped sulfur/polyacrylonitrile as a high-capacity cathodein lithium-sulfur batteries

Krishnaveni Kalaiappan, Subadevi Rengapillai, Sivakumar Marimuthu, Raja Murugan, Premkumar Thiru

期刊论文

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

Wen XUE, Weiliang JIN, Hiroshi YOKOTA,

期刊论文

Denitrification performance and sulfur resistance mechanism of Sm–Mn catalyst for low temperature NH-SCR

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

zirconium-based metal-organic framework-801 films on carbon cloth as shuttle-inhibiting interlayers for lithium-sulfur

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