RFWD3 acts as a tumor promotor in the development and progression of bladder cancer

Background. Bladder cancer is one of the most commonly diagnosed malignancies of the urinary system with relatively poor prognosis and insufficient treatment strategies. RFWD3 is an E3 ligase whose function is rarely investigated in malignant tumors. Methods. A tissue microarray was used for evaluating RFWD3 expression in clinical samples and its correlation with tumor characteristics and patients’ prognosis. RFWD3 knockdown and overexpression cell models were constructed for conducting loss-of-function and gain-of-function assays. qPCR and western blotting were used for detecting mRNA and protein levels of RFWD3, respectively. MTT assay, colony formation assay, flow cytometry, wound-healing assay and transwell assay were carried out to demonstrate the change of cell phenotypes upon RFWD3 knockdown. Results. RFWD3 expression was relatively higher in bladder cancer tissues than in normal tissues, which is correlated with higher N stage and poorer prognosis of patients. Knockdown of RFWD3 in bladder cancer cells significantly inhibited cell proliferation, colony formation, promote cell apoptosis and restrained cell migration. Overexpression of RFWD3 induced the opposite effects. Conclusions. It was illustrated that RFWD3 possesses excellent tumor-promoting ability in bladder cancer. Accordingly, RFWD3 may be a promising therapeutic target in the targeted therapy of bladder cancer, which is worth further research

Bifurcations for a predator–prey system with two delays

AbstractIn this paper, a predator–prey system with two delays is investigated. By choosing the sum τ of two delays as a bifurcation parameter, we show that Hopf bifurcations can occur as τ crosses some critical values. By deriving the equation describing the flow on the center manifold, we can determine the direction of the Hopf bifurcations and the stability of the bifurcating periodic solutions. In addition, special attention is paid to the global continuation of local Hopf bifurcations. Using a global Hopf bifurcation result of [J. Wu, Symmetric functional differential equations and neural networks with memory, Trans. Amer. Math. Soc. 350 (1998) 4799–4838], we may show the global existence of periodic solutions

Analysis of Load-Carrying Capacity for Redundant Free-Floating Space Manipulators in Trajectory Tracking Task

The aim of this paper is to analyze load-carrying capacity of redundant free-floating space manipulators (FFSM) in trajectory tracking task. Combined with the analysis of influential factors in load-carrying process, evaluation of maximum load-carrying capacity (MLCC) is described as multiconstrained nonlinear programming problem. An efficient algorithm based on repeated line search within discontinuous feasible region is presented to determine MLCC for a given trajectory of the end-effector and corresponding joint path. Then, considering the influence of MLCC caused by different initial configurations for the starting point of given trajectory, a kind of maximum payload initial configuration planning method is proposed by using PSO algorithm. Simulations are performed for a particular trajectory tracking task of the 7-DOF space manipulator, of which MLCC is evaluated quantitatively. By in-depth research of the simulation results, significant gap between the values of MLCC when using different initial configurations is analyzed, and the discontinuity of allowable load-carrying capacity is illustrated. The proposed analytical method can be taken as theoretical foundation of feasibility analysis, trajectory optimization, and optimal control of trajectory tracking task in on-orbit load-carrying operations