Optically-Nonactive Assorted Helices Array with Interchangeable Magnetic/Electric Resonance

We report here the designing of optically-nonactive metamaterial by assembling metallic helices with different chirality. With linearly polarized incident light, pure electric or magnetic resonance can be selectively realized, which leads to negative permittivity or negative permeability accordingly. Further, we show that pure electric or magnetic resonance can be interchanged at the same frequency band by merely changing the polarization of incident light for 90 degrees. This design demonstrates a unique approach to construct metamaterial.Comment: 15 pages, 4 figure

Docosahexaenoic acid has influence on action potentials and transient outward potassium currents of ventricular myocytes

<p>Abstract</p> <p>Background</p> <p>There are many reports about the anti-arrhythmic effects of ω-3 polyunsaturated fatty acids, however, the mechanisms are still not completely delineated. The purpose of this study was to investigate the characteristics of action potentials and transient outward potassium currents (I_to) of Sprague-Dawley rat ventricular myocytes and the effects of docosahexaenoic acid (DHA) on action potentials and I_to.</p> <p>Methods</p> <p>The calcium-tolerant rat ventricular myocytes were isolated by enzyme digestion. Action potentials and I_toof epicardial, mid-cardial and endocardial ventricular myocytes were recorded by whole-cell patch clamp technique.</p> <p>Results</p> <p><b>1.</b> Action potential durations (APDs) were prolonged from epicardial to endocardial ventricular myocytes (<it>P </it>< 0.05). <b>2.</b> I_tocurrent densities were decreased from epicardial to endocardial ventricular myocytes, which were 59.50 ± 15.99 pA/pF, 29.15 ± 5.53 pA/pF, and 12.29 ± 3.62 pA/pF, respectively at +70 mV test potential (<it>P </it>< 0.05). <b>3.</b> APDs were gradually prolonged with the increase of DHA concentrations from 1 μmol/L to 100 μmol/L, however, APDs changes were not significant as DHA concentrations were in the range of 0 μmol/L to 1 μmol/L. <b>4.</b> I_tocurrents were gradually reduced with the increase of DHA concentrations from 1 μmol/L to 100 μmol/L, and its half-inhibited concentration was 5.3 μmol/L. The results showed that there were regional differences in the distribution of action potentials and I_toin rat epicardial, mid-cardial and endocardial ventricular myocytes. APDs were prolonged and I_tocurrent densities were gradually reduced with the increase of DHA concentrations.</p> <p>Conclusion</p> <p>The anti-arrhythmia mechanisms of DHA are complex, however, the effects of DHA on action potentials and I_tomay be one of the important causes.</p

Bis(7-amino-2,4-dimethyl-1,8-naphthyridine)dinitratocadmium(II)

In the title compound, [Cd(NO3)2(C10H11N3)2], two naph­thyridine ring systems are coordinated to the Cd ion through the two N atoms in a bidentate chelating mode, whereas the remaining coordination sites are occupied by two O atoms from two different nitrate groups to complete the octahedral geometry. Inter­moleular N—H⋯O hydrogen bonds link the mol­ecules to form a one-dimensionnal sheet parallel to the ac plane. Weak slipped π–π stacking involving the naphthyridine ring systems stabilizes the structure