Generalization of Linearized Gouy-Chapman-Stern Model of Electric Double Layer for Nanostructured and Porous Electrodes: Deterministic and Stochastic Morphology

We generalize linearized Gouy-Chapman-Stern theory of electric double layer for nanostructured and morphologically disordered electrodes. Equation for capacitance is obtained using linear Gouy-Chapman (GC) or Debye-$\rm{\ddot{u}}$ckel equation for potential near complex electrode/electrolyte interface. The effect of surface morphology of an electrode on electric double layer (EDL) is obtained using "multiple scattering formalism" in surface curvature. The result for capacitance is expressed in terms of the ratio of Gouy screening length and the local principal radii of curvature of surface. We also include a contribution of compact layer, which is significant in overall prediction of capacitance. Our general results are analyzed in details for two special morphologies of electrodes, i.e. "nanoporous membrane" and "forest of nanopillars". Variations of local shapes and global size variations due to residual randomness in morphology are accounted as curvature fluctuations over a reference shape element. Particularly, the theory shows that the presence of geometrical fluctuations in porous systems causes enhanced dependence of capacitance on mean pore sizes and suppresses the magnitude of capacitance. Theory emphasizes a strong influence of overall morphology and its disorder on capacitance. Finally, our predictions are in reasonable agreement with recent experimental measurements on supercapacitive mesoporous systems

Interaction of Temperature and Light in the Development of Freezing Tolerance in Plants

Abstract Freezing tolerance is the result of a wide range of physical and biochemical processes, such as the induction of antifreeze proteins, changes in membrane composition, the accumulation of osmoprotectants, and changes in the redox status, which allow plants to function at low temperatures. Even in frost-tolerant species, a certain period of growth at low but nonfreezing temperatures, known as frost or cold hardening, is required for the development of a high level of frost hardiness. It has long been known that frost hardening at low temperature under low light intensity is much less effective than under normal light conditions; it has also been shown that elevated light intensity at normal temperatures may partly replace the cold-hardening period. Earlier results indicated that cold acclimation reflects a response to a chloroplastic redox signal while the effects of excitation pressure extend beyond photosynthetic acclimation, influencing plant morphology and the expression of certain nuclear genes involved in cold acclimation. Recent results have shown that not only are parameters closely linked to the photosynthetic electron transport processes affected by light during hardening at low temperature, but light may also have an influence on the expression level of several other cold-related genes; several cold-acclimation processes can function efficiently only in the presence of light. The present review provides an overview of mechanisms that may explain how light improves the freezing tolerance of plants during the cold-hardening period

Light and Temperature Signalling at the Level of CBF14 Gene Expression in Wheat and Barley

The wheat and barley CBF14 genes have been newly defined as key components of the light quality-dependent regulation of the freezing tolerance by the integration of phytochrome-mediated light and temperature signals. To further investigate the wavelength dependence of light-induced CBF14 expression in cereals, we carried out a detailed study using monochromatic light treatments at an inductive and a non-inductive temperature. Transcript levels of CBF14 gene in winter wheat Cheyenne, winter einkorn G3116 and winter barley Nure genotypes were monitored. We demonstrated that (1) CBF14 is most effectively induced by blue light and (2) provide evidence that this induction does not arise from light-controlled CRY gene expression. (3) We demonstrate that temperature shifts induce CBF14 transcription independent of the light conditions and that (4) the effect of temperature and light treatments are additive. Based on these data, it can be assumed that temperature and light signals are relayed to the level of CBF14 expression via separate signalling routes

Efficacy of chemopreventive agent, Dipteracanthus prostratus, on 1,2-dimethylhydrazine induced colon carcinogenesis

Aim: The aim of this study was to evaluate the effect of Dipteracanthus prostratus extracts on 1,2-dimethyl hydrazine (DMH) induced colon cancer in rats. Materials and Methods: To achieve this objective DMH model was selected to evaluate the effect of D. prostratus extracts on colon cancer. The study was carried out on 48 male Wistar rats divided into six groups. Group I served as a control. Groups II and III served as a positive control received ethanolic extract (500 mg/kg) and aqueous extract (500 mg/kg), respectively. Group IV served as a tumor bearing group received (20 mg/kg) DMH. Groups V and VI served as a treatment group received DMH (20 mg/kg) + ethanolic extract (500 mg/kg) and aqueous extract (500 mg/kg), respectively. Lipid peroxidation (LPO) was studied by measuring the formation of thiobarbituric acid reactive substances, catalase (CAT), glutathione peroxidase (GP X ), and reduced glutathione (GSH) in the liver and colonic tissues of DMH administered rats. Results: (1) Decreased levels of LPO in the colonic tissues; (2) decreased activities of antioxidant enzymes LPO, CAT, GP X , and GSH levels in the tissues on DMH treatment. D. prostratus supplementation during the entire period stages of carcinogenesis significantly reversed these activities. Conclusion: These results indicate that D. prostratus may be a potential chemopreventive agent against DMH induced colon cancer

<span style="font-size:10.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-US">Electronic structure and elastic properties of ATiO₃ (A = Ba, Sr, Ca) perovskites: A first principles study</span>

102-109The elastic constants of perovskite oxides ATiO3 (A = Ba, Sr, Ca) in the cubic phase are calculated using the full-potential linearized augmented plane wave method within the density functional theory in its generalized gradient approximation. The modified Becke-Johnson potential (TB-mBJ) is applied for the electronic structure calculation. The calculated results are used to obtain the Young's modulus, shear modulus, Poisson’s ratio, isotropic shear modulus, longitudinal, transverse and average sound velocities, Zener anisotropy factor, Kleinman parameter and Debye temperature of the systems. The calculated results are compared with the available experimental data