This paper presents a method for expanding horizontal flow variables in data using the free solutions to the shallow-water system as a basis set. This method for equatorial wave expansion of instantaneous flows（EWEIF...This paper presents a method for expanding horizontal flow variables in data using the free solutions to the shallow-water system as a basis set. This method for equatorial wave expansion of instantaneous flows（EWEIF） uses dynamic constraints in conjunction with projections of data onto parabolic cylinder functions to determine the amplitude of all equatorial waves.EWEIF allows us to decompose an instantaneous wave flow into individual equatorial waves with a presumed equivalent depth without using temporal or spatial filtering a priori.Three sets of EWEIF analyses are presented. The first set is to confirm that EWEIF is capable of recovering the individual waves constructed from theoretical equatorial wave solutions under various scenarios. The other two sets demonstrate the ability of the EWEIF method to derive time series of individual equatorial waves from instantaneous wave fields without knowing a priori exactly which waves exist in the data as well as their spatial and temporal scales using outputs of an equatorial β-channel shallow-water model and ERA-Interim data. The third set of demonstrations shows, for the first time, the continuous evolutions of individual equatorial waves in the stratosphere whose amplitude is synchronized with the background zonal wind as predicted by quasi-biennial oscillation theory.展开更多
Objective To investigate the effects of BmkTXKβ, a newly purified ' long chain' peptide inhibitor of K+ channels from the Chinese scorpion Buthus martensi Karsch (BmK), on the electrophysiological properties ...Objective To investigate the effects of BmkTXKβ, a newly purified ' long chain' peptide inhibitor of K+ channels from the Chinese scorpion Buthus martensi Karsch (BmK), on the electrophysiological properties of isolated rabbit atrial myocytes.Methods The standard whole-cell patch-clamp technique was used to study the effects of multiple concentrations of BmkTXKp on potassium currents and action potentials.Results BmkTXKp produced concentration-dependent prolongation of action potential duration at 20%, 50%, and 90% repolarization (APD20,50,90) without any use-dependence. Meanwhile, it had no significant effect on RMP, APA, or Vmax(n =9). At a dose of 1 μmol/L, BmkTXKβ decreased lto by 41.4% (n = 10, P<0. 01) at a membrane potential of +50 mV [from (13.63±0.87) pA/pF to (7.98±0.78) pA/pF]. lto was reduced significantly with an IC50 value of 1.82μmol/L (95% confidence interval: 1.47 -2.17 μmol/L), in a clear concentration-dependent manner. BmkTXKp blocked IKS and lKs,tail with an IC50 of 20.15 μmol/L and a 95% confidence interval of 16. 93 -23. 37 μmol/L At a concentration of 10 μmol/L, BmkTXKβ blocked both IKS( mean reduction 37. 3% ±4. 2% , P<0. 01, n=7) and lKs,tall(mean reduction 35. 8% ±4. 1%, P<0. 01, n=7). At 0 mV, 10 μmol/L BmkTXKp inhibited both lKr ( mean reduction 40.5% ±2.6%, P < 0. 01, n=6) and lKr,tail ( mean reduction 42. 3% ±2. 9% , P<0. 01, n =6). Blocking of lKr by BmkTXKβ occurred in a concentration-dependent manner, with an IC50 of 17. 21 μmol/L (95% confidence interval; 14. 76 -19. 66 μmol/L). An absence of effects on IK1 was observed for BmkTXKβ, with no change in reversal-potential (n =6, P>0. 05).Conclusions BmkTXKβexerts direct blocking effects on several potassium channels involved in cardiac repolarization, and has a strong effect on prolonging the repolarization of rabbit cardiomyocytes without reverse frequency dependence. This finding suggests that BmkTXKβ could be a promising class Ⅲ drug for anti-arrhythmic therapy without the risk of proarrhythmia.展开更多
基金supported by grants from the National Science Foundation(Grant No.AGS-1354834)the NASA Interdisciplinary Studies Program(Grant No.NNH12ZDA001NIDS)
文摘This paper presents a method for expanding horizontal flow variables in data using the free solutions to the shallow-water system as a basis set. This method for equatorial wave expansion of instantaneous flows（EWEIF） uses dynamic constraints in conjunction with projections of data onto parabolic cylinder functions to determine the amplitude of all equatorial waves.EWEIF allows us to decompose an instantaneous wave flow into individual equatorial waves with a presumed equivalent depth without using temporal or spatial filtering a priori.Three sets of EWEIF analyses are presented. The first set is to confirm that EWEIF is capable of recovering the individual waves constructed from theoretical equatorial wave solutions under various scenarios. The other two sets demonstrate the ability of the EWEIF method to derive time series of individual equatorial waves from instantaneous wave fields without knowing a priori exactly which waves exist in the data as well as their spatial and temporal scales using outputs of an equatorial β-channel shallow-water model and ERA-Interim data. The third set of demonstrations shows, for the first time, the continuous evolutions of individual equatorial waves in the stratosphere whose amplitude is synchronized with the background zonal wind as predicted by quasi-biennial oscillation theory.
基金the Natural Science Foundation of Hubei Province (No. SJ-971073)
文摘Objective To investigate the effects of BmkTXKβ, a newly purified ' long chain' peptide inhibitor of K+ channels from the Chinese scorpion Buthus martensi Karsch (BmK), on the electrophysiological properties of isolated rabbit atrial myocytes.Methods The standard whole-cell patch-clamp technique was used to study the effects of multiple concentrations of BmkTXKp on potassium currents and action potentials.Results BmkTXKp produced concentration-dependent prolongation of action potential duration at 20%, 50%, and 90% repolarization (APD20,50,90) without any use-dependence. Meanwhile, it had no significant effect on RMP, APA, or Vmax(n =9). At a dose of 1 μmol/L, BmkTXKβ decreased lto by 41.4% (n = 10, P<0. 01) at a membrane potential of +50 mV [from (13.63±0.87) pA/pF to (7.98±0.78) pA/pF]. lto was reduced significantly with an IC50 value of 1.82μmol/L (95% confidence interval: 1.47 -2.17 μmol/L), in a clear concentration-dependent manner. BmkTXKp blocked IKS and lKs,tail with an IC50 of 20.15 μmol/L and a 95% confidence interval of 16. 93 -23. 37 μmol/L At a concentration of 10 μmol/L, BmkTXKβ blocked both IKS( mean reduction 37. 3% ±4. 2% , P<0. 01, n=7) and lKs,tall(mean reduction 35. 8% ±4. 1%, P<0. 01, n=7). At 0 mV, 10 μmol/L BmkTXKp inhibited both lKr ( mean reduction 40.5% ±2.6%, P < 0. 01, n=6) and lKr,tail ( mean reduction 42. 3% ±2. 9% , P<0. 01, n =6). Blocking of lKr by BmkTXKβ occurred in a concentration-dependent manner, with an IC50 of 17. 21 μmol/L (95% confidence interval; 14. 76 -19. 66 μmol/L). An absence of effects on IK1 was observed for BmkTXKβ, with no change in reversal-potential (n =6, P>0. 05).Conclusions BmkTXKβexerts direct blocking effects on several potassium channels involved in cardiac repolarization, and has a strong effect on prolonging the repolarization of rabbit cardiomyocytes without reverse frequency dependence. This finding suggests that BmkTXKβ could be a promising class Ⅲ drug for anti-arrhythmic therapy without the risk of proarrhythmia.
