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Histone Modifications Pattern Associated With a State of Mesenchymal Stem Cell Cultures Derived From Amniotic Fluid of Normal and Fetus‐Affected Gestations 下载免费PDF全文
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Influence of Mesenchymal Stem Cells Conditioned Media on Proliferation of Urinary Tract Cancer Cell Lines and Their Sensitivity to Ciprofloxacin 下载免费PDF全文
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Erik Hahn Peter Wild Elisabeth M. Schraner Hans U. Bertschinger Markus Hner Shirley A. Müller Ueli Aebi 《Journal of structural biology》2000,132(3):241
The F18 fimbriae expressed by porcine toxigenic Escherichia coli strains are 1- to 2-mm-long filaments that mediate the adhesion of the bacteria to enterocytes. The backbone of these fimbriae is built from a major structural 15.1-kDa protein, FedA. The structure of isolated negatively stained F18 fimbriae imaged by dark-field scanning transmission electron microscopy (STEM) was resolved to approximately 2 nm. Analyzing their helical symmetry showed the axially repeating units to alternate in a “zigzag” manner around the helical axis with an axial rise of 2.2 nm. Two repeating units give rise to the observed 4.3-nm helical repeat, which is practically identical to the pitch of the one-start helix formed. Additionally, an axially repeating pattern with a 27-nm spacing was found on rotary-shadowed fimbriae. Mass-per-length determination of unstained F18 fimbriae by STEM revealed the axially repeating unit to have a molecular mass of 25.4 kDa, indicating that it is a FedA monomer, with the difference in mass arising from the minor subunits, FedE and FedF. The presence of the latter two proteins might cause the observed 27-nm axial pattern. 相似文献
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This article describes the use of project-based instruction in activities and labs intended to develop higher-order thinking skills with high school students and pre-service teachers through the use of soap making. 相似文献
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Immunophenotypic Characterization of Human Glioblastoma Stem Cells: Correlation With Clinical Outcome 下载免费PDF全文
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