A magnetic ground state is revealed for the first time in zigzag-edged carbon nanoscrolls(ZCNSs)from spin-unrestricted density functional theory calculations.Unlike their flat counterpart-zigzag-edged carbon nanoribbons,which are semiconductors with spin-degenerate electronic structure-ZCNSs show a variety of magnetic configurations,namely spin-selective semiconductors,metals,semimetals,quasi-half-metals,and half-metals.To the best of our knowledge,this is the first discovery of quasi-half-metals and half-metals in a pure hydrocarbon without resort to an external electric field.In addition,we calculated the spin-dependent transportation of the semiconducting ZCNSs with 12 and 20 zigzag chains,and found that they are 13% and 17% at the Fermi level,respectively,suggesting that ZCNS can be an effective spin filter.
Lin LaiJing LuLu WangGuangfu LuoJing ZhouRui QinYu ChenHong LiZhengxiang GaoGuangping LiWai Ning MeiYutaka MaedaTakeshi Akasakaand Stefano Sanvito
Background The traditional Chinese medicine injury, but the mechanism of its action is not we protective role of Tongxinluo. Tongxinluo can protect myocardium against documented. We examined the involvement schaemia/reperfusion of nitric oxide in the Methods Miniswine were randomized to four groups of seven： sham, control, Tongxinluo and Tongxinluo coadministration with a nitric oxide synthase inhibitor N^ωnitro-L-arginine （L-NNA, 10 mg/kg i.v.）. Three hours after administration of Tongxinluo, the animals were anaesthetised and the left anterior descending coronary artery ligated and maintained in situ for 90 minutes followed by 3 hours of reperfusion before death. Area of no reflow and necrosis and risk region were determined pathologically by planimetry. The degree of neutrophil accumulation in myocardium was obtained by measuring myeloperoxidase activity and histological analysis. Myocardial endothelial nitric oxide synthase activity and vascular endothelial cadherin content were measured by colorimetric method and immunoblotting analysis respectively. Results Tongxinluo significantly increased the local blood flow and limited the infarct and size of no reflow. Tongxinluo also attenuated myeloperoxidase activity and neutrophil accumulation in histological sections and maintained the level of vascular endothelial cadherin and endothelial nitric oxide synthase activity in the reflow region when compared with control group. The protection of Tongxinluo was counteracted by coadministration with L-NNA. Conclusions Tongxinluo may limit myocardial ischaemia and protect the heart against reperfusion injury. Tongxinluo regulates synthesis of nitric oxide by altering activity of endothelial nitric oxide synthase.
Background Oxidative stress has been implicated in the onset and progression of diabetes. Tongxinluo is a traditional Chinese medicine with potent antioxidant properties. The aim of this study was to test the hypothesis that pretreatment with Tongxinluo has similar effects as melatonin on preventing hyperglycemia and beta-cell damage in a rat model of streptozotocin （STZ）-induced diabetes. Methods Forty male Sprague Dawley rats were randomly assigned to four groups （n=10 each）： normal control （NC） group; STZ group （70 mg/kg, i.p.）; Tongxinluo （1.0 g-kg-^-d-1） pretreated （TXL＋STZ） group and melatonin （200 iJg-kg-~.d-1） pretreated （MLT＋STZ） group. Tongxinluo and melatonin were administered by gavage beginning 8 days before STZ injection and continuing until the end of the study （15 days after STZ administration）. Blood glucose levels and body weights, malondialdehyde （MDA）, and reduced glutathione （GSH） levels were measured, and immunofluorescence studies were performed in all of the groups. Results Pretreatment with Tongxinluo, as with melatonin, attenuated severe hyperglycemia and weight loss induced by STZ.. In pancreatic homogenates, MDA levels were significantly lower and GSH levels were significantly higher in Tongxinluo pretreated group and in melatonin pretreated group than those in STZ group. Values of insulin staining were significantly improved in Tongxinluo pretreated group and in melatonin pretreated group as compared with those in STZ group. Conclusions Tongxinluo, as melatonin, prevented hyperglycemia and beta-cell destruction induced by STZ in rats through reducing oxidative stress in pancreatic tissues. Tongxinluo may provide an alternative therapy for the prevention and treatment of diabetes.
WANG Huai-qingZOU Jun-jieZHOU Xiang-haiJI Li-nongLIU Zhi-min
Microstructure and hydrological profiles were collected along two cross-shelf sections from the deep slope to the shallow water in the north of Taiwan Island in the summer of 2006.While the tidal currents on the shelf were dominated by the barotropic tide with the current ellipse stretched across the shelf,significant internal tides were observed on the slope.The depth-mean turbulent kinetic energy(TKE)dissipation rate on the shelf was 10^-6W kg^-1,corresponding to a diapycnal diffusivity of 10^-2 m^2s^-1.The depth-mean TKE dissipation rate on the slope was 1×10^-7 Wkg^-1,with diapycnal diffusivity of 3×10^-4m^2s^-1.The shear instability associated with internal tides largely contributed to the TKE dissipation rate on the slope from the surface to 150 m,while the enhanced turbulence on the shelf was dominated by tidal or residual current dissipations caused by friction in the thick bottom boundary layer(BBL).In the BBL,the Ekman currents associated with the northeastward Taiwan Warm Current were identified,showing a near-bottom velocity spiral,which agreed well with the analytical bottom Ekman solution.
