Stiffness modeling of compliant parallel mechanisms and applications in the performance analysis of a decoupled parallel compliant stage.

This paper investigates the stiffness modeling of compliant parallel mechanism (CPM) based on the matrix method. First, the general compliance matrix of a serial flexure chain is derived. The stiffness modeling of CPMs is next discussed in detail, considering the relative positions of the applied load and the selected displacement output point.

[CRISPR-Cas system and coevolution of bacteria and phages].

In response to the challenge from phages, bacteria evolve a number of defense systems against phage invasion. Meanwhile, the phages evolve multiple counter-defense mechanism as well under the selection pressure from bacteria. The evolution relationship between bacteria and phages, as well as the functional mechanism, still remains to be uncovered.

Protective effect of inducible nitric oxide synthase inhibitor on pancreas transplantation in rats.

Aim: To investigate the effect of inducible nitric oxide synthase inhibitor, aminoguanidine, on pancreas transplantation in rats.

Methods: A model of pancreas transplantation was established in rats. Streptozotocin-induced diabetic male Wistar rats were randomly assigned to sham-operation control group (n = 6), transplant control group (n = 6), and aminoguanidine (AG) treatment group (n = 18).

Elevation of vascular endothelial growth factor production and its effect on revascularization and function of graft islets in diabetic rats.

Aim: To determine whether the elevated vascular endothelial growth factor (VEGF) expression produced by the transfected vascular endothelial cells (VECs) could stimulate angiogenesis of the graft islets and exert its effect on the graft function.

Methods: Thirty diabetic recipient rats were divided into three groups (n=10 per group). In the control group, 300 IEQ islets were transplanted in each rat under the capsule of the right kidney, which were considered as marginal grafts.

[Inhibition of nuclear factor kappa B attenuates multiple organ injury following ruptured abdominal aortic aneurysm: an experiment with rats].

Objective: To investigate the effect of inhibition of nuclear factor kappa B on multiple organ injury following ruptured abdominal aortic aneurysm.

Methods: Forty-five Wistar rats underwent catheterization to observe the intestinal microcirculation blood flow, and were randomly divided into 3 equal groups. Rats of the ruptured abdominal aortic aneurysm (RAAA) group underwent laparotomy and extraction of blood to cause hemorrhage shock for 1 h (hemorrhagic shock phase), by the end of this phase normal saline at the dose of 50 ml/kg was injected intravenously, after that the abdominal aorta and bilateral common iliac arteries were blocked with artery clamps for 45 min so as to cause lower torso ischemia, and then the extracted blood was reperfused.

Islet transplantation for diabetic rats through the spleen.

Background: Islet transplantation is considered a potentially curative treatment for diabetic mellitus. The aim of this study was to assess the feasibility of islet transplant through the spleen.

Methods: Both donor and recipient Wistar rats (BW150+/-20 g) were provided by the Animal Center of China Medical University, Shenyang, China.