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Planning for electricity generation systems is a very important task and should take environmental and economic factors into account. This paper reviews the existing metrics and methods in evaluating energy sustainability, and we propose a sustainability assessment index system. The input indexes include generation capacity, generation cost, and land use. The output indexes include desirable and undesirable parts. The desirable outputs are total electricity generation and job creation. The undesirable outputs are external supply risk and external costs associated with the environment and health. The super-efficiency data envelopment analysis method is used to calculate the sustainability of electricity generation systems of 23 countries from 2005 to 2014. The three input indexes and three undesirable output indexes are used as the input variables. The two desirable outputs are used as the output variables. The results show that most countries' electricity generation sustainability values have decreasing trends. In addition, nuclear and hydro generation have positive effects. Solar, wind, and fossil fuel generation have negative effects on sustainability.

Inwardly rectifying potassium channels play an important role in the maintenance of membrane potential in neurons and myocardium. Identification of functional regulation mechanisms concerning these channels may lead to the development of specific modulators for these channels. Genistein is an isoflavone with potent inhibitory activity on protein tyrosine kinase. In this study, we have found that among three members of the Kir family (Kir2.3, Kir2.1, and Kir3.4* [a highly active mutant of Kir3.4, Kir3.4-S143T]) we tested, genistein significantly inhibited Kir2.3 currents. Using the two-electrode voltage clamp technique, we have demonstrated that micromole concentrations of genistein concentration-dependently and reversibly inhibited the currents of Kir2.3 channel expressed in Xenopus oocytes with an IC50 of 16.9+/-2.8 microM. Using the whole-cell patch-clamp technique, genistein also inhibited the currents of Kir2.3 channel expressed in HEK293 cells with an IC50 of 19.3+/-3.2 microM. Genistein had little or no effect on Kir2.1 and Kir3.4* currents. The effect of genistein on Kir2.3 currents was not affected by vanadate, a potent protein tyrosine phosphatase inhibitor. Furthermore, the effect of genistein was not mimicked by daidzein, an inactive analogue of genistein, or another potent tyrosine kinase inhibitor, tyrphostin 23. Chimeras between Kir2.3 and Kir2.1 channels were constructed to identify molecular basis that distinguished the effect of genistein on these channels. It was found that the transmembrane domains and the pore region of Kir2.3 channel were important determinant for high sensitivity for genistein inhibition.

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