Experiments on the Resistance of a Large Transport Vessel Navigating in the Arctic Region in Pack Ice Conditions

In this study, we carried out model tests to investigate the ice failure process and the resistance experienced by a transport vessel navigating in the Arctic region in pack ice conditions. We tested different navigation velocities, ice plate sizes, and ice concentrations. During the tests, we closely observed several phenomena, including the modes of interaction of the ice ship and the moving and failure modes of ice. We also measured the vessel resistances under different conditions. The test results indicate that the navigation velocity is a significant determinant of the moving and failure modes of ice. Moreover, vessel resistance is remarkably dependent on the ice concentration and navigation velocity. The variances of the mean and maximum resistance are also compared and discussed in detail.

Induction of resistance vessel dilation by ginger root juice,possibly through extracellular signal-regulated kinase 1/2 and endothelial nitric oxide synthase activation in endothelial cells

Objective:To investigate the effects of ginger root juice on contractibility of resistance blood vessels from mice and on activation of extracellular signal-regulated kinase 1/2(ERK1/2)and endothelial nitric oxide synthase(eNOS)in human endothelial cells.Methods:Juice was prepared from semi-dry ginger roots.Mesenteric artery rings were dis-sected from healthy adult C57BL/J6 mice.Primary human umbilical vein endothelial cells(HU-VECs)were isolated from umbilical cords of normal full-term babies.The contractibility of the dissected vessel rings in the presence or absence of ginger root juice at 0.1%(v/v)after potassium(100 mM KCL)stimulation was measured by wire myography.The phosphorylation levels of ERK1/2 and eNOS in the presence of ginger root juice in the culture medium at 0,0.025%,0.05%,0.1%,and 0.2%(v/v)in HUVECs were assessed by western blotting analysis.Results:An immediate sharp increase in the contractile activity was observed in mesenteric artery rings in response to KCL stimulation.Ginger root juice effectively attenuated the KCL-mediated vessel contraction.Moreover,ginger root juice significantly increased phosphorylation of ERK1/2 and eNOS in a dose-dependent manner.Conclusions:Ginger root juice is capable of relaxing resistance blood vessels.Activation of ERK1/2 and eNOS through phosphorylation in endothelial cells may be a mechanism underlying the vasodilator activity of ginger root.