96 research outputs found

    Comparative study of differentiating human pluripotent stem cells into vascular smooth muscle cells in hydrogel-based culture methods

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    Vascular smooth muscle cells (VSMCs), which provides structural integrity and regulates the diameter of vasculature, are of great potential for modeling vascular-associated diseases and tissue engineering. Here, we presented a detailed comparison of differentiating human pluripotent stem cells (hPSCs) into VSMCs (hPSCs-VSMCs) in four different culture methods, including 2-dimensional (2D) culture, 3-dimensional (3D) PNIPAAm-PEG hydrogel culture, 3-dimensional (3D) alginate hydrogel culture, and transferring 3- dimensional alginate hydrogel culture to 2-dimensional (2D) culture. Both hydrogel-based culture methods could mimic in vivo microenvironment to protect cells from shear force, and avoid cells agglomeration, resulting in the extremely high culture efficiency (e.g., high viability, high purity and high yield) compared with 2D culture. We demonstrated hPSC-VSMCs produced from hydrogel-based culture methods had better contractile phenotypes and the potential of vasculature formation. The transcriptome analysis showed the hPSC-VSMCs derived from hydrogel-based culture methods displayed more upregulated genes in vasculature development, angiogenesis and blood vessel development, extracellular matrix compared with 2D culture. Taken together, hPSC-VSMCs produced from hydrogel-based culture system could be applied in various biomedical fields, and further indicated the suitable development of alginate hydrogel for industrial production by taking all aspects into consideration

    An Improved Method for Calculating Bending Moment and Shearing Force of Beam in Numerical Modelling

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    In view of the problem that it is difficult to obtain the displacement, internal force and damage status from one beam model established in most numerical analysis models, an improved method for calculating bending moment and shearing force is presented in this paper, which can change this situation. This method portrays how to obtain the internal force from model established using 3-D solid element which can be able to show the failure process easily. The research results are as follows: (1) Deflection equation of beam established using 3-D solid element can be fitted by extracting displacement value of each node on the axis, thus bending moment and shearing force value can be directly figured out by putting the equation of deflection curve into approximately differential equation of deflection curve. (2) The reliability of the results calculated in this method would be easily affected by force, shape of cross section and the highest degree of polynomial, etc. When the beam is in a state of small deformation and the highest degree of polynomial is kept between 20 and 30, the results will be more reliable, besides, beam model whose shape of the cross section is rectangular is more suitable for the method than the circular one. (3) This method can always be applied to beam model, no matter its constraint conditions and loading conditions are complex or not

    PTLp : Partial Transport Lp Distances

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    Optimal transport and its related problems, including optimal partial transport, have proven to be valuable tools in machine learning for computing meaningful distances between probability or positive measures. This success has led to a growing interest in defining transport-based distances that allow for comparing signed measures and, more generally, multi-channeled signals. Transport distances are notable extensions of the optimal transport framework to signed and possibly multi-channeled signals. In this paper, we introduce partial transport distances as a new family of metrics for comparing generic signals, benefiting from the robustness of partial transport distances. We provide theoretical background such as the existence of optimal plans and the behavior of the distance in various limits. Furthermore, we introduce the sliced variation of these distances, which allows for faster comparison of generic signals. Finally, we demonstrate the application of the proposed distances in signal class separability and nearest neighbor classification

    Engineered Microenvironment for Manufacturing Human Pluripotent Stem Cell-Derived Vascular Smooth Muscle Cells

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    Human pluripotent stem cell-derived vascular smooth muscle cells (hPSC-VSMCs) are of great value for disease modeling, drug screening, cell therapies, and tissue engineering. However, producing a high quantity of hPSC-VSMCs with current cell culture technologies remains very challenging. Here, we report a scalable method for manufacturing hPSC-VSMCs in alginate hydrogel microtubes (i.e., AlgTubes), which protect cells from hydrodynamic stresses and limit cell mass to \u3c400 \u3eÎĽm ensure efficient mass transport. The tubes provide cells a friendly microenvironment, leading to extremely high culture efficiency.We have shown that hPSC-VSMCs can be generated in 10 days with high viability, high purity, and high yield (~5.0 x 108 cells/mL). Phenotype and gene expression showed that VSMCs made in AlgTubes and VSMCs made in 2D cultures were similar overall. However, AlgTube-VSMCs had higher expression of genes related to vasculature development and angiogenesis, and 2D-VSMCs had higher expression of genes related to cell death and biosynthetic processes

    Non-Agonistic Bivalent Antibodies That Promote c-MET Degradation and Inhibit Tumor Growth and Others Specific for Tumor Related c-MET

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    The c-MET receptor has a function in many human cancers and is a proven therapeutic target. Generating antagonistic or therapeutic monoclonal antibodies (mAbs) targeting c-MET has been difficult because bivalent, intact anti-Met antibodies frequently display agonistic activity, necessitating the use of monovalent antibody fragments for therapy. By using a novel strategy that included immunizing with cells expressing c-MET, we obtained a range of mAbs. These c-MET mAbs were tested for binding specificity and anti-tumor activity using a range of cell-based techniques and in silico modeling. The LMH 80 antibody bound an epitope, contained in the small cysteine-rich domain of c-MET (amino acids 519–561), that was preferentially exposed on the c-MET precursor. Since the c-MET precursor is only expressed on the surface of cancer cells and not normal cells, this antibody is potentially tumor specific. An interesting subset of our antibodies displayed profound activities on c-MET internalization and degradation. LMH 87, an antibody binding the loop connecting strands 3d and 4a of the 7-bladed β-propeller domain of c-MET, displayed no intrinsic agonistic activity but promoted receptor internalization and degradation. LMH 87 inhibited HGF/SF-induced migration of SK-OV-3 ovarian carcinoma cells, the proliferation of A549 lung cancer cells and the growth of human U87MG glioma cells in a mouse xenograft model. These results indicate that c-MET antibodies targeting epitopes controlling receptor internalization and degradation provide new ways of controlling c-MET expression and activity and may enable the therapeutic targeting of c-MET by intact, bivalent antibodies

    Web-based interactive graph visualization

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    Graphs are powerful tools to convey the relationships between objects. It has a natural visual representation as nodes and connecting links arranged in space. Software that automates graph visualization, editing and analysis will save considerable cognitive efforts for graph study [1]. However, current open-source tools only provide a limited set of functionalities. To resolve this limitation, Grapher is created to enhance the experience for web-based graph visualization, editing, and analysis. To enable an enjoyable graph visualization experience, Grapher has a simple user interface with rich user interaction and dynamic visualization features. Besides describing the graph content in a JSON text format, it also supports visual editing, allowing the user to modify the graph structure and attributes in an intuitive way. Moreover, several graph comparison algorithms are implemented to help the user to gain insights into the graph data. Two graphs can be compared side by side, with their similarity and difference highlighted. Grapher is a Node.js application using Express.js Framework. Graph comparison algorithms are implemented in Python. It makes use of Neo4j Graph Database for persistent storage. This report is a comprehensive documentation of Project Grapher. We start with the motivation and objectives of this project followed by a discussion on the limitation of similar applications and a survey of graph visualization technologies. The following chapters documents the software development lifecycle of Grapher, including Requirement Specification, Project Planning, Design, Implementation, and Testing. Finally, yet importantly, we will conclude the report and discuss the future improvement of Grapher.Bachelor of Engineering (Computer Science

    Study on the influence of soil moisture and plant roots on slope stability of dump

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    Under the background of ecological civilization construction and comprehensive promotion of "green mine" construction in China, for the waste dump formed by a large amount of abandoned soil and slag in the process of mineral resource production, it is one of the important contents of mine ecological restoration to restore and reconstruct the ecology, especially the slope vegetation. Based on the origin of the dump, when rainfall or irrigation water infiltrates into the soil, the physical and mechanical properties of slope soil are changed, and the shear strength of soil is continuously reduced, which has a negative impact on the slope stability. In this paper, we take south mining of DaTang open-pit mine as an example, through field investigation and sampling, laboratory analysis and the computer software analysis method, we set up soil shear strength parameters under different soil water content and different depth of plant roots, using the Slope stability of Slope/W module, establishing the model of slope . Based on limit equilibrium theory to calculate the safety factor, it is concluded that under the condition of the bare Slope stability of Slope soil water safety threshold is 14%. The root system of slope vegetation plays an important role in slope stability, in which the effect of leguminous vegetation on slope stability is obviously better than that of gramineous vegetation. When the soil moisture of slope is 20%, the slope stability coefficient can be increased by 7%

    Study on the Water-Saving Irrigation Technology in the Slope Vegetation Restoration of the Mining Area Dump

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     With the development and utilization of coal resources, the surface vegetation is destroyed and soil erosion is more and more serious. Open-pit coal mine on typical steppe causes very strong artificial erosion landform remodeling, especially mining dump slope, needing to take reasonable measures for its vegetation restoration. Irrigation is one of main means to ensure the vegetation growth on anthropogenic landforms, which can make up for a lack of atmospheric precipitation and coordinated uneven distribution of water space and enhance its competitiveness. The research focuses on different irrigation methods in the vegetation restoration of coal mine dump slope, which is slight spraying, drip irrigation and micro irrigation, where water shortages, lack of regular power and slope topography. Suitable irrigation methods are determined better to vegetation restoration and reconstruction through studying the characteristics of three irrigation methods, soil moisture content, vegetation coverage and biomass on the ground. Appropriate way of irrigation not only make more rational use of limited water resources, but also promote plant growth and protect coal mine slope, effectively reduce soil erosion

    Laser additive manufacturing of bimetallic structure from TC4 to IN718 via Ta/Cu multi-interlayer

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    Titanium alloys and nickel-based alloys have their own unique properties, and the bimetallic structure composed of the two alloys can be widely used in the aerospace field. However, the bimetallic structure which is fabricated by directly joining titanium alloys and nickel-based alloys via traditional methods is more sensitive to cracks due to the formation of intermetallic compounds. In this work based on laser additive manufacturing (LAM) technology, the TC4/IN718 bimetallic structure without metallurgical defects (such as cracks) was successfully fabricated via a Ta/Cu multi-interlayer. The test results indicated that the Ta/Cu multi-interlayer could effectively avoid the generation of Ti–Ni and Ti–Cu intermetallic compounds between TC4 and IN718. A good metallurgical combination was formed in each interface from TC4 to IN718 without metallurgical defects. The phase evolution from the TC4 region to the IN718 region was as follows: α -Ti →  α -Ti +  β -Ta →  β -Ta →  β -Ta +  γ -Cu →  γ -Cu →  γ -Cu + γ -Ni + laves →  γ -Ni + laves. The ultimate tensile strength of the bimetallic structure at room temperature was 369.32 MPa
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