Preparation and Properties of Nylon 6,6 Grafted Graphene Composites.

Nylon 6,6 composite fiber containing grafted graphene (nylon 6,6-g-graphene) was prepared by nylon and graphene grafted with acyl chloride (graphene-COCl) through extrusion reaction. Graphene-COCl was prepared through acid-treated reacting, graphene with thionyl chloride functional group. The chemical structure of nylon 6,6-g-graphene obtained using reactive extrusion technique was characterized using Fourier transform infrared spectrometer. It was found that this kind of composite fiber has the characteristics of less amount of graphene and excellent mechanical properties and has certain application prospects. Nylon 6,6-g-graphene dispersed evenly in the Nylon composite. But pristine graphene exhibited aggregate structure when composite was produced by pristine graphene through reactive extrusion. The composite reinforcement was increased obviously with the increase content of grafted graphene. After examined, the nylon/nylon 6,6-g-graphene with a certain content grafted graphene composite exhibited high level of reinforcement, and mechanical properties were improved.

Therapeutical effect of Radix Aconiti and Astragalus extracts on models of experimental bradycardia animal.

The antibradycardia effect of extract of RAE (Radix Aconiti and Astragalus) on bradycardia animal models were evaluated. Bradycardia rat model was induced by amiodarone or propranolol, and sick sinus syndrome (SSS) rabbit model was induced by chemical stimulation on surface of sinus node. The heart rates of the animal models were calculated according to ECG recording. The value of sino-atrial conduction time (SACT) and correcting sinus node recovery time (CSNRT) of SSS rabbit model were measured by multi-channel physiological recorder. The blood flow of aorta and coronary the diabolic pressure of normal rat hearts in vitro were measured. Treatment with RAE could increase the heart rate of bradycardia animals induced by amiodarone, propranolol, or SSS rabbit model significantly. Treatment with RAE could decrease in the value of SACT and CSNRT of SSS rabbit model. Moreover, treatment with RAE could increase the blood flow of aorta and coronary and could decrease diabolic pressure of normal rat hearts in vitro. RAE has heart-rate-increasing effect, which might be related to its ameliorating the autorhythmicity of sinus node and improving the sino-atrial conductive function. Moreover, RAE could ameliorate cardiac blood supply and enhance cardiac function.

The protective effect of MT-α-glucan against streptozotocin (STZ)-induced NIT-1 pancreatic ß-cell damage.

The protective effect of an alpha-glucan (designated here as MT-α-glucan) from fruit body of maitake (Grifola frondosa) on NIT-1 pancreatic ß-cells damaged by streptozotocin (STZ) in vitro was investigated. The cell viability, insulin secretion, the activity of superoxide dismutase (SOD), glutathione peroxidase (GSHpx) and the content of reduced glutathione (GSH) increased significantly when the cells were incubated with MT-α-glucan (400, 200 µg ml(-1)). The content of malondialdehyde (MDA), nitric oxide (NO) production, and the activity of NO synthase (NOS), inducible NOS (iNOS) decreased significantly when the cells were incubated with MT-α-glucan. The destructive changes of NIT-1 cells ameliorated when incubated with MT-α-glucan under microscopic observation. These data suggested that MT-α-glucan had obvious protective effect on NIT-1 pancreatic ß-cells damaged by STZ, which might be related to its effects of decreasing levels of ß-cell-destroying factors such as oxidative stress and NO synthesis.

Hypoglycaemic and hypolipidaemic activities of sesamin from sesame meal and its ability to ameliorate insulin resistance in KK-Ay mice.

BACKGROUND: The ability of sesamin from sesame meal to ameliorate insulin resistance in KK-Ay mice (an animal model of type 2 diabetes) was evaluated. RESULTS: Treatment with sesamin (100 or 50 mg kg(-1)) significantly decreased the level of fasting plasma glucose, glycosylated serum protein, serum insulin, triglycerides, cholesterol, free fatty acid and malondialdehyde content of livers. Treatment with sesamin significantly increased the content of hepatic glycogen, reduced glutathione and the activity of superoxide dismutase and glutathione peroxidase. Moreover, the insulin-binding capacity to liver crude plasma membranes increased and histopathological changes of the pancreas were ameliorated in the treatment group. CONCLUSION: Sesamin has hypoglycaemic, hypolipidaemic and the ability to ameliorate insulin resistance in KK-Ay mice, which might be related to its effect on insulin receptors, and thus increases insulin sensitivity.