Full-Scale Isogeometric Topology Optimization of Cellular Structures Based on Kirchhoff-Love Shells

Cellular thin-shell structures are widely applied in ultralightweight designs due to their high bearing capacity and strength-to-weight ratio.In this paper,a full-scale isogeometric topology optimization(ITO)method based on Kirchhoff-Love shells for designing cellular tshin-shell structures with excellent damage tolerance ability is proposed.This method utilizes high-order continuous nonuniform rational B-splines(NURBS)as basis functions for Kirchhoff-Love shell elements.The geometric and analysis models of thin shells are unified by isogeometric analysis(IGA)to avoid geometric approximation error and improve computational accuracy.The topological configurations of thin-shell structures are described by constructing the effective density field on the controlmesh.Local volume constraints are imposed in the proximity of each control point to obtain bone-like cellular structures.To facilitate numerical implementation,the p-norm function is used to aggregate local volume constraints into an equivalent global constraint.Several numerical examples are provided to demonstrate the effectiveness of the proposed method.After simulation and comparative analysis,the results indicate that the cellular thin-shell structures optimized by the proposed method exhibit great load-carrying behavior and high damage robustness.

Isogeometric Analysis for Linear and Nonlinear Cantilever in CAD

A novel method for the mechanical simulation of linear and nonlinear Timoshenko-beams has been presented.The beam strains are based on a kinematic assumption where the shear deformation and rotational are considered.Applying the isoparametric concept the kinematic quantities are approximated using NURBS(non-uniform Rational B-spline)functions.This numerical simulation can be called as isogeometric analysis,which can improve the efficiency in CAD(computer aided design).Furthermore,an efficient Code has been developed and the results for two numerical applications are given in the end.

Extracellular CIRP dysregulates macrophage bacterial phagocytosis in sepsis

In sepsis, macrophage bacterial phagocytosis is impaired, but the mechanism is not well elucidated. Extracellular cold-inducible RNA-binding protein (eCIRP) is a damage-associated molecular pattern that causes inflammation. However, whether eCIRP regulates macrophage bacterial phagocytosis is unknown. Here, we reported that the bacterial loads in the blood and peritoneal fluid were decreased in CIRP^(−/−) mice and anti-eCIRP Ab-treated mice after sepsis. Increased eCIRP levels were correlated with decreased bacterial clearance in septic mice. CIRP−/− mice showed a marked increase in survival after sepsis. Recombinant murine CIRP (rmCIRP) significantly decreased the phagocytosis of bacteria by macrophages in vivo and in vitro. rmCIRP decreased the protein expression of actin-binding proteins, ARP2, and p-cofilin in macrophages. rmCIRP significantly downregulated the protein expression of βPIX, a Rac1 activator. We further demonstrated that STAT3 and βPIX formed a complex following rmCIRP treatment, preventing βPIX from activating Rac1. We also found that eCIRP-induced STAT3 phosphorylation was required for eCIRP’s action in actin remodeling. Inhibition of STAT3 phosphorylation prevented the formation of the STAT3-βPIX complex, restoring ARP2 and p-cofilin expression and membrane protrusion in rmCIRP-treated macrophages. The STAT3 inhibitor stattic rescued the macrophage phagocytic dysfunction induced by rmCIRP. Thus, we identified a novel mechanism of macrophage phagocytic dysfunction caused by eCIRP, which provides a new therapeutic target to ameliorate sepsis.

国际基因工程机器大赛对本科生综合能力培养模式的探索

华东理工大学生物工程学院从高水平专业比赛出发,以学生的兴趣为切入点,依托强大的科研和教学基地,构建具有"生物创客"精神的人才培养体系和创新实践能力培养体系。充分发挥学生主观能动性,提升了生物工程类相关专业本科生的科研素养和综合能力。对传统的高校教育模式进行了有效探索,满足了生命科学飞速发展时期对创新型人才的迫切需求。

Enhanced bioproduction of chitin in engineered Pichia pastoris

Biopolymer chitin and its derivatives have a wide range of applications in different fields.Chitin is primarily produced from marine crustacean by strong acid and strong alkali treatment.To reduce the environmental hazardous in the production of chitin,post-fermentation fungal biomass waste like fungi cell walls provides a viable alternative source for chitin.In this study,improved chitin content in yeast cell wall was achieved by overexpressing chitin biosyntheic pathway related genes.The chitin content was 51.5μg/mg cell wall and 122.9μg/mg cell wall in strain GS-1.10(gfat,uap and chs1 genes overexpression)and strain GS-2.6(gfat,gna1,agm1,uap and chs1 genes overexpression),which were 44.3%and 244.4%higher than that in control strain GS115,respectively.By overexpressing another chitin synthase gene(chs3),the chitin content in strain GS-3.10 was further increased to 136.2μg/mg cell wall,which was 10.8%and 281.6%higher than that in GS-2.6 and in control GS115,respectively.Moreover,chitin yield was further improved by various culture conditions optimization,and reached 162.4μg/mg cell wall,which was 4.43 times of that in the starting strain GS115.The final titer of chitin was 2.23 g/L culture broth in 84 h fed-batch fermentation in a 5 L bioreactor.To our knowledge,this is the first report of chitin production in engineered Pichia pastoris via biosynthetic pathway enhancement.