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The objective of this research is to find the electronic commerce business model suitable for traditional stationers which focus on enterprise customers. Summarized from different researchers¡¦ opinions for the definition of business model, we grouped them into 4 components: object, parties, mechanism, and distribution. Besides, according to the evolution of B2B electronic commerce, we classify two typical B2B web models. They are Basic electronic commerce and E-marketplace. The results of this research shows that current B2B web models widely used are not suitable for the attributes of domestic stationery industry and also can not meet the needs of traditional stationers. This study suggests a new B2B web model named Localized E-marketplace and provides concrete proposals which can be taken as an example for traditional stationers or dot.com companies which are interested in MRO market.

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Endothelial cells (ECs) are part of almost every human organ, and disturbance in their function can cause several human diseases such as pulmonary arterial hypertension. We sought to develop an in vitro model to derive ECs from human induced pluripotent stem cells (hiPSCs) in an effort to develop future regenerative therapies or disease models. By stimulating signaling pathways gleaned from prior studies of the early embryonic development of endothelial cells and their precursor germlayer, mesoderm, hiPSCs were differentiated in vitro using a media containing 10ng/ml of Activin, FGF2, VEGF and BMP4 to induce mesoderm over 4 days, followed by VEGF and FGF2 to subsequently specify ECs. By day 12, putative endothelial cells identified by the co-expression of CD31, CD144 and KDR, emerged and could be sorted and re-plated in endothelial maintenance media for expansion over several passages. Time series characterization of mRNA and protein gene expression indicates that to form endothelial cells, hiPSCs developmentally differentiate first into a posterior primitive streak-like stage (indicated by high T and low FOXA2 expression), then into a heterogeneous population of mesodermal subsets (day 4). Subsequently, lateral plate mesoderm cells predominate over intermediate or paraxial mesoderm. To understand the role of BMP4 in this process, each factor was withheld from various stages of the protocol. Results indicate that before day 4, BMP4 alone is necessary and sufficient to direct cells through posterior primitive streak into mesodermal progenitors that upon subsequent VEGF/FGF2 exposure can give rise to CD31+CD144+KDR+ endothelial-like cells. In contrast, BMP4 is dispensable after day4, whereas VEGF and FGF2 are dispensable in the first 4 days of the protocol. To develop a disease model hiPSCs from patients with BMPR2 mutations associated with pulmonary hypertension were generated by reprogramming their archived fibroblasts. By differentiating these patient-specific iPSCs into mesodermal progenitors and ECs using our protocol, preliminary results indicate that the induction of mesodermal cells by day 4 was diminished in cells carrying BMPR2 mutations,, but whether their efficiency of differentiation into ECs is affected by these mutations remains in question. It can be concluded from this project, that we develop an in vitro differentiation model that replicates the developmental pathways of mesodermal and EC derivation in embryos, and suggests that BMP4 is necessary and sufficient to derive mesodermal subsets with EC competence but is dispensable for subsequent endothelial lineage specification. / 2018-09-26T00:00:00Z

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This thesis deals with thermal optimization of electric machines. There are described the connections of finite element methods with optimizations algorithms. This connection is used for modifications of brushless motor construction. The main parts of this work are the complete thermal analysis of EC machine and modifications of cooling.

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