Epithelial-to-mesenchymal transition (EMT) is a well-studied biological process that takes place during embryogenesis, carcinogenesis and tissue fibrosis. During EMT, the polarized epithelial cells with a cuboidal architecture adopt an elongated fibroblast-like morphology. This process is accompanied by the expression of many EMT-specific molecular markers. While the molecular mechanism leading to EMT has been well established, the effects of matrix topography and microstructure have not been clearly elucidated. Synthetic scaffolds mimicking the mesh-like structure of the basement membrane with an average fiber diameter of 0.5 μm and 5 μm were produced via electrospinning of poly(ε-caprolactone) (PCL) and were used to test the significance of fiber diameter on EMT. Cell-adhesive peptide motifs were conjugated to the fiber surface to facilitate cell attachment. Madin-Darby Canine Kidney (MDCK) cells grown on these substrates showed distinct phenotypes. On 0.5 μm substrates, cells grew as compact colonies with an epithelial phenotype. On 5 μm scaffolds, cells were more individually dispersed and appeared more fibroblastic. Upon addition of hepatocyte growth factor (HGF), an EMT inducer, cells grown on the 0.5 μm scaffold underwent pronounced scattering, as evidenced by the alteration of cell morphology, localization of focal adhesion complex, weakening of cell-cell adhesion, and upregulation of mesenchymal markers. By contrast, HGF did not induce a pronounced scattering of MDCK cells cultured on the 5.0 μm scaffold. Collectively, our results show that the alteration of the fiber diameter of proteins found in the basement membrane may create enough disturbances in epithelial organization and scattering that might have important implications in disease progression.
Composite materials were successfully made out of plant oil-based resin and northern red oak (Quercus robur) leaves collected in the fall. The viscosities of the bio-based resins (MAESO and MAELO) were suited to high temperature resin transfer molding (RTM) and vacuum-assisted resin transfer molding (VARTM) processing. The leaves have a waxy epidermal surface layer that needs to be dewaxed prior to use in a composite part. We used different treatments (such as benzene-ethanol, boiling water, and strong detergent) to dewax the leaves; all three methods seem to give good results; but boiling water and strong detergent were considered the best treatments for the dewaxing of leaves and boiling water was considered the greenest dewaxing method. The compatibility between the resin and the leaves was improved with a silane treatment which resulted in composites with higher mechanical stiffness than the resin itself. With 10 wt % leaves, we obtained an improvement in the composite modulus of about 14% from which we could estimate the leaf modulus at about 5.3 GPa. An alternative method to produce biocomposites from leaves without the need for silane treatments consists in carbonizing the leaves first at 215 C for 12 h, and then at 450 C for 1 h. The composites made with leaves and bioresins derived from functionalized triglycerides have the potential for use in high volume applications with low costs such as housing, construction, civil infrastructure, toys, and furniture. The use of leaves as a biocomposite filler has several advantages including (a) reduced cost, (b) improved properties of the resin, (c) composites with high bio content, (d) removal of a waste material with subsequent prevention of burning with attendant health hazards, and (e) interesting design aesthetics for interior and exterior decoration.
Antimicrobials help in the prevention and treatment of infections and are crucial for animal production, but overuse can result in antimicrobial resistance. Hence, understanding data quality on livestock antimicrobial use is essential. We assessed frequency of reporting, completeness, and concordance of reported data and availability of human resources and infrastructure in 14 districts in Sierra Leone. This was a cross-sectional study involving a review of district and sub-district animal treatment forms submitted from January 2016 to August 2019. Out of the 14 districts, only 3 had filled forms available for review: A total of 6 (0.97% of 616 expected) district forms and 79 (1.15% of 6840 expected) sub-district forms. Data between district and sub-district treatment forms were fully discordant. Hence, completeness of data could not be assessed. All districts had livestock officers (barring one) and livestock assistants but no veterinarians. The gap in community animal health workers ranged from 14 to 100% per district. No districts had a functional computer or internet access. Reporting was non-existent in 11 districts and poor in the other 3. Resources are urgently needed to address critical gaps in human resources and capacity and computer and Internet connectivity to develop critical One Health surveillance functions at the national and sub-national levels.
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