Electron beam irradiation of low-density polyethylene filled with metal hydroxides for wire and cable applications

The effects of electron beam irradiation for crosslinking of polymers used for wire and cable insulations are still being researched. In this research, the influence of electron beam irradiation on the different blends of low-density polyethylene (LDPE) filled with aluminum trihydrate and magnesium hydroxide (ATH, MH) were studied. It was revealed by melt flow index, tensile strength, and elongation at break tests that addition of MH to LDPE increases the adhesion forces inside polymer matrices more efficient than similar ATH/LDPE compounds. Field emission scanning electron microscopy test showed that MH is platy in structure and more homogenous mixed than ATH with LDPE. The results on thermogravimetric analysis and limiting oxygen index tests revealed that the thermal stability and incombustibility properties of MH blends are more efficient than similar ATH blends. Meanwhile, it was observed by smoke density test that MH blends produce the lowest smoke density compared with virgin LDPE and similar ATH blends. It was also observed that increasing irradiation by electron beam had impressive affections on the density, gel content, and mechanical properties for all the polymeric samples in this study

Study and Production of Silicone Rubber and Polyethylene Alloy

Linear silicone rubber and polyethylene alloy produced from extrusion-injecting process will be present in separate phases. While samples are mixed with 1% dicumylperoxide, DCP, and injected in extruder, an alloy is almost formed. In addition, when the samples containing silicon rubber with vinyl group are mixed with polyethylene and passed in the vicinity of electron beam, a similar reaction occurs, as confirmed from FTIR spectrum. The water contact angles for the samples has been listed in the article. Furthermore, the crystallinity of samples produced via electron beam method is more than that obtained from peroxide method. On the other hand, the tensile strengths of produced samples via both the methods are about 20% more than that of polyethylene. Also, the tensile strength of the produced samples in electron beam method (12.86 MPa) is better than that of the produced samples in peroxide method (11.99 MPa). </jats:p

Development of lung metastases in new animal models of OSCC

Background Oral Squamous Cell Carcinoma (OSCC) is the sixth most common cancer worldwide. While the early stages present a positive outcome, the 5 years overall survival of advanced ones is less than 50%, especially when regional or distant metastases occur. In the preclinical setting, few animal models of metastatic OSCC have been developed and the growth of metastases is still poorly understood. Here we report the development of two mouse models of metastatic OSCC by orthotopic and intravenous (IV) injection. Methods For the orthotopic model, HSC-3 cells expressing luciferase and GFP were injected in the tongue of 5-6 weeks old athymic nude mice. The presence of the primary tumor and lung metastasis was evaluated by in vivo and ex vivo imaging techniques and further confirmed by H&E and human pan-cytokeratin staining. For the IV model, 7-8 weeks old athymic nude mice were injected with tumor cells isolated from HSC-3 lung metastasis of a mouse injected IV. Results In the orthotopic model, lung and regional lymph node metastases were present in 40%-80% of the animals by ex vivo imaging 40-50 days after cell injection. Histological analysis of the primary tumors showed infiltration of the deep muscular layer. Histology and IHC confirmed the presence of large lymph node and lung metastases. In the IV model, large lung metastases were present in the 60% of the animals by ex vivo imaging. The presence of lung metastases was further confirmed by histology. No regional lymph node metastases were detected in this model. Conclusions Both regional lymph node and lung metastases were observed in the orthotopic model of OSCC. In the IV model, only lung metastases were present. Both models can be used to investigate the mechanism of metastases in OSCC

Множества и функции : Для слушателей ФПК

Simulated body fluid (SBF) has been used previously by others to aid in predicting the bioactivity and osseointegration potential of materials. This paper details a study carried out using a CO2 laser to induce a number of surface patterns which inherently modified both the surface chemistry and surface topography giving rise to a difference in apatite response between each sample. These induced patterns gave rise to a reduction in hydrophilicity with contact angles of up to +10° being observed. Furthermore, following immersion in SBF for 14 days each sample was weighed revealing an increase in weight of up to 0.029 g indicating that an apatite layer had begun to form. In addition, energy dispersive X-ray analysis identified the presence of calcium and phosphorous, two elements which support osteoblast cell response. When comparing with an as-received sample it was found that the laser induced patterned samples gave rise to more layer crystals forming suggesting a more optimized surface for osteoblast cell growth and proliferation