Mechanical Properties and Stress Strain Relationship Models for Bamboo Scrimber

In order to investigate the basic mechanical properties and stress strain relationship model for bamboo scrimber manufactured based on a new technique,a large quantities of experiments have been carried out.Based on the analysis of the test results,the following conclusions can be drawn.Two main typical failure modes were classified for bamboo scrimber specimens both under tension parallel to grain and tension perpendicular to grain.Brittle failure happened for all tensile tests.The slope values for the elastic stages have bigger discreteness compared with those for the specimens under tensile parallel to grain.The failure modes for bamboo scrimber specimens under compression parallel to grain could be divided into four.Only one main failure mode happened both for the bending specimens and the shear specimens.With the COV values of 28.64 and 25.72 respectively,the values for the strength and elastic modulus under tensile perpendicular to grain have the largest discreteness for bamboo scrimber.From the point of CHV values,the relationship among the mechanical parameters for bamboo scrimber were proposed based on the test results.Compared with other green building materials,bamboo scrimber manufactured based on a new technique has better mechanical performance and could be used in construction area.Three stress strain relationship models which are four-linear model,quadratic function model,and cubic function model were proposed for bamboo scrimber specimens manufactured based on a new technique.The latter two models gives better prediction for stress strain relationship in elastic plastic stage.

Efficacy of transcatheter arterial chemoembolization combined with sorafenib in inhibiting tumor angiogenesis in a rabbit VX2 liver cancer model

Background:The aim of this study was to investigate the effects of transcatheter arterial chemoembolization(TACE)combined with sorafenib on tumor angiogenesis.Materials and methods:Thirty New Zealand rabbit VX2 liver cancer model animals were divided into five groups,which received either normal saline(A),TACE(B),sorafenib(C),sorafenib followed by TACE(D),or TACE followed by sorafenib(E).Serum vascular endothelial growth factor(VEGF)levels were measured before and after TACE via ELISA.Immunohistochemistry for CD34 was performed to evaluate microvessel density(MVD),and ultrasonography was used to access tumor volume.Results:VEGF levels declined in group C but increased significantly on the 3 rd post-operative day in groups B,D,and E.Levels decreased after the 7 th post-operative day.Peak levels were significantly lower in group D than in groups B and E.On the 14 th post-operative day,VEGF levels were the lowest in group C,followed by those in groups D and B.MVD was the lowest in group C followed by that in group D and E,and was the highest in group B.Group D had the smallest tumor volume.HE staining of tumor tissues from group C showed apoptosis in a scattered patchy pattern,whereas in groups B,D,and E,large areas of tumor cell necrosis were visible.Conclusion:TACE can up-regulate serum VEGF levels,which in turn accelerates the formation of new blood vessels.Thus,TACE combined with sorafenib inhibits VEGF and angiogenesis,and pre-operative administration of sorafenib has a more superior anti-angiogenic effect than post-operative administration.