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Chondrogenic commitment of human umbilical cord blood and umbilical cord-derived mesenchymal stem cells induced by the supernatant of chondrocytes:A comparison study

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Animal Models and Experimental Medicine 2024年第6期7卷 793-801页

作者： xingfu li Zhenhan Deng Wei Lu Department of Orthopedics Shenzhen Second People's Hospital(The First Affiliated Hospital of Shenzhen UniversityHealth Science Center)ShenzhenChina Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging National-Regional Key Technology Engineering Laboratory for Medical UltrasoundSchool of Biomedical EngineeringShenzhen University Medical SchoolShenzhenChina Department of Orthopedics The First Affiliated Hospital of Wenzhou Medical UniversityWenzhouChina

Background:Native cartilage has low capacity for regeneration because it has very few progenitor *** umbilical cord blood-derived mesenchymal stem cells(hUCB-MSCs)and human umbilical cord-derived MSCs(hUC-MSCs)have been employed as promising sources of stem cells for cartilage injury *** of hyaline cartilage from MSCs remains a challenging *** paracrine factors secreted by chondrocytes possess the capability to induce chondrogenesis from ***:The conditioned medium derived from chondrocytes was utilized to induce chondrogenic differentiation of hUCB-MSCs and *** expression levels of collagen type I alpha 1 chain(Col1a1),collagen type II alpha 1 chain(Col2a1),and SRY-box transcription factor 9(SOX9)were assessed through quantitative real-time polymerase chain reaction(qRT-PCR),Western blot(WB),and immunofluorescence(IF)*** elucidate the mechanism of differentiation,the concentration of transforming growth factor-β1(TGF-β1)in the conditioned medium of chondrocytes was quantified using enzyme-l inked immunosorbent assay(EliSA).Meanwhile,the viability of cells was assessed using Cell Counting Kit-8(CCK-8)***:The expression levels of Col2a1 and SOX9 were found to be higher in induced hUC-MSCs compared to those in induced *** conditioned medium of chondrocytes contained TGF-β*** CCK-8 assays revealed that the proliferation rate of hUC-MSCs was significantly higher compared to that of ***:The chondrogenic potential and proliferation capacity of hUC-MSCs surpass those of hUCB-MSCs,thereby establishing hUC-MSCs as a superior source of seed cells for cartilage tissue engineering.

关键词： cartilage diseases chondrogenic differentiation mesenchymal stem cells

Mechanistic study of the effect of flexible fixation and load-bearing stress environment on fracture healing and shaping

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Animal Models and Experimental Medicine 2024年第6期7卷 816-823页

作者： xingfu li Zhenhan Deng Wei Lu Department of Sports Medicine Shenzhen Second People's Hospital(The First Affiliated Hospital of Shenzhen University)ShenzhenGuangdongChina Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging National-Regional Key Technology Engineering Laboratory for Medical UltrasoundSchool of Biomedical EngineeringShenzhen University Medical SchoolShenzhenGuangdongChina Department of Orthopedics Surgery The First Affiliated Hospital of Wenzhou Medical UniversityWenzhouZhejiangChina

Background:The biomechanical environment created by suture-button fixation Latarjet is conducive to the healing and shaping of the transplanted coracoid,but its mechanism remains *** latest research has found that the absence of stem cell chemokine(CXCL12)impeded bone regeneration in Sonic Hedgehog(SHH)-deficient ***,whether the biomechanical environment affects SHH and CXCL12 function has not been ***:Rat fracture models were constructed to simulate stress environments under non-l oad-bearing and load-bearing *** fracture healing and shaping,as well as the expression levels of SHH and CXCL12,were assessed through gross viewing,micro-computed tomography(micro-CT),and histochemical ***:Under flexible fixation,the relative bone volume(BV/TV)of rats exposed to the load-bearing stress environment was significantly higher than that of rats under a non-l oad-bearing stress environment(p≤0.05).Adverse bone shaping was not observed in rats subjected to flexible *** levels of SHH and CXCL12in load-bearing rats exhibited significant elevation(p≤0.05).Under a load-bearing stress environment,no significant difference was observed in the BV/TV between the flexible fixation group and the rigid fixation group(p≥0.05),but there was excessive hyperplasia of the fracture callus in the rigid fixation *** levels of SHH and CXCL12 in rats subjected to rigid fixation were significantly elevated(p≤0.05).Conclusions:Flexible fixation and load-bearing stress environment may contribute to bone healing and shaping by influencing the levels of SHH and CXCL12,suggested that this mechanism may be relevant to the healing and shaping of the transplanted coracoid after suture-button fixation Latarjet.

关键词： CXCL12 flexible fixation sonic hedgehog stress environment

Construction of Multilayer Porous Scaffold Based on Magnetically Guided Assembly of Microfiber

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Journal of Systems Science & Complexity 2018年第3期31卷 581-595页

作者： li xingfu WANG Huaping SHI Qing SUN Tao HUANG Qiang FUKUDA Toshio Intelligent Robotics Institute School of Mechatronical Engineering Beijing Institute of Technology Beijing 100081 China Key Laboratory of Biomimetic Robots and Systems Ministry of Education Beijing 100816 China Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing 100081 China

This paper proposes a novel method of magnetically guided assembly to construct multi- layer porous scaffold for three-dimensional cell culture by apply magnetic microfibers. Microfibers are composed of biocompatible and biodegradable alginate solution with homogeneous magnetic nanopar- ticles, which are continuously spun from a microfluidic device by precise pressure control of the syringe pump. Magnetic nanoparticles enable the control of magnetic field on microfibers. Meanwhile, mag- netized device combining with a round permanent magnet are utilized to guide the distribution of spouted microfibers. The device is composed by pure iron wire arrays and wax, which stimulates pow- erful magnetic flux density and magnetic field gradients for the capture and assembly of microfibers. Thus, magnetic microfibers are spun on desired places of the magnetized device by motion control of the micromanipulation robot, and precise locations are adjusted by magnetic force couple with the assist of glass micropipette. Afterwards, microfibers are spatially organized by periodic magnetic force and crossed layer-by-layer to form micro-pore structure with both length and width of 650μm. Finally, the authors construct a multilayer microfiber-based scaffold with high porosity to provide a satisfactory environment for long-term cell culture. The experimental results demonstrate the effectiveness of the proposed method.

关键词： Magnetically guided assembly magnetic microfiber magnetized device periodic magneticforce multilayer porous scaffold.

Quantitative Evaluation on Urban Ecosystem Carrying Capacity in Tianjin Binhai New Area

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Chinese Journal of Population,Resources and Environment 2009年第4期7卷 64-68页

作者： li xingfu Xu He Institute of Environmental Science and Engineering Nankai University Tianjin 300071 China

Based on the concept of ecosystem carrying capacity,the indicator system of quantitative assessment was set up,which consisted of support indicator system and pressure indicator *** the factor analysis method was used to screen the indicator *** from the traditional indicator weight determination based on the absolute values of the coefficients of regression equation,the squares of factor loadings in the rotated component matrix were attempted to determine the weights of 40 assessment *** result shows that ecological support system and pressure system in Binhai New Area are relatively balanced among six years,and the developing level of urban ecosystem is basically healthy on the ***,due to continuously increasing pressure of the resources consumption caused by the rapid growth of the second industry,which is the Leading Industry of Binhai New Area,the ecosystem carrying capacity reached the minimum in 2005.

关键词： ecosystem carrying capacity factor analysis Binhai New Area

Wavefield continuation datuming using a near surface model

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Applied Geophysics 2007年第2期4卷 94-100页

作者： Cui xingfu li Hongbing Hu Ying liang Hong Qi li Geophysical Technology Department Research Institute of Petroleum Exploration ＆ Development PetroChina. Beijing（100083）

When topography and low velocity zone differences vary greatly, conventional vertical static time shifts will cause wavefield distortion and influence wave equation seismic imaging for seismic data acquired on a complex near surface. In this paper, we propose an approach to datum correction that combines a joint tomography inversion with wavefield continuation to solve the static problem for seismic data on rugged acquisition topography. First, the near surface model is obtained by refracted wave tomography inversion. Second, the wavefield of sources and receivers are continued downward and upward to accomplish datum correction starting from a flat surface and locating the datum above topography. Based on the reciprocal theorem, Huygens＇ and Fresnel principles, the location of sources and receivers, and regarding the recorded data on the surface as a secondary emission, the sources and receivers are upward-continued to the datum above topography respectively. Thus, the datum correction using joint tomography inversion and wavefield continuation with the condition of a complex near surface is accomplished.

关键词： Complex near surface tomography inversion wavefield continuation datum correction.

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塑料滑道的摩擦系数方程

润滑与密封 1998年第6期23卷 53-56页

作者：李新福武汉水利电力大学 430072

根据摩擦的粘着变形理论和粘弹性力学,导出了塑料滑道摩擦系数方程。对NL150塑料、油尼龙及CS—2B滑道实验研究表明,该方程具有较高的准确性。

关键词：摩擦系数塑料滑道粘弹性闸门水利枢纽

响应变量缺失时纵向数据下部分线性模型的广义经验似然推断

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统计与决策 2019年第14期35卷 13-17页

作者：公徐路李幸福山西农业大学软件学院

文章对响应变量缺失时纵向数据下部分线性模型的兴趣参数估计问题借助经验似然方法,基于二次推断函数提出了回归系数和基准函数的广义经验似然比函数,得到了相应的极大经验似然估计。证明了所提出的经验对数似然比渐进于χ~2分布,由此... 详细信息

文章对响应变量缺失时纵向数据下部分线性模型的兴趣参数估计问题借助经验似然方法,基于二次推断函数提出了回归系数和基准函数的广义经验似然比函数,得到了相应的极大经验似然估计。证明了所提出的经验对数似然比渐进于χ~2分布,由此构造了相应的置信域和逐点置信区间。

关键词：部分线性模型经验似然缺失数据纵向数据

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中国废旧轮胎利用途径的环境影响评价

环境污染与防治 2010年第11期32卷 99-102页

作者：李兴福徐鹤南开大学环境科学与工程学院天津300071

运用生命周期评价方法,比较了中国废旧轮胎4种利用途径(常温生产60目胶粉、动态脱硫生产再生胶、微负压热裂解、土法炼油)的环境影响。结果表明,根据环境影响(以生态指数表征),中国废旧轮胎利用途径的优先度排序为微负压热裂解>常温生... 详细信息

运用生命周期评价方法,比较了中国废旧轮胎4种利用途径(常温生产60目胶粉、动态脱硫生产再生胶、微负压热裂解、土法炼油)的环境影响。结果表明,根据环境影响(以生态指数表征),中国废旧轮胎利用途径的优先度排序为微负压热裂解>常温生产60目胶粉>动态脱硫生产再生胶>土法炼油。其中,前3种利用途径产生的环境影响主要是由燃料生产过程产生的间接环境影响构成。

关键词：废旧轮胎生命周期评价方法生态指数间接环境影响

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校长的使命在于永无止境的文化引领

曲靖师范学院学报 2019年第5期38卷 122-128页

作者：李兴富云南民族大学附属中学

文化引领是校长管理学校的最高境界,校长的使命在于永无止境的文化引领。文化引领作为办学治校的手段和方法,应该实现从“小班额”到“小班化”的管理提升、从专业能力到职业精神的内涵提升、从专属教育到文化品位的凝聚和提升,以便将... 详细信息

文化引领是校长管理学校的最高境界,校长的使命在于永无止境的文化引领。文化引领作为办学治校的手段和方法,应该实现从“小班额”到“小班化”的管理提升、从专业能力到职业精神的内涵提升、从专属教育到文化品位的凝聚和提升,以便将学校管理推向现代化发展轨道。

关键词：管理提升教育内涵提升文化品质凝聚提升