Here we found that the enantioselectivity of G-quadruplex DNA-based Diels-Alder reaction can be switched by just changing Na(+) to K(+), which is ascribed to the structural transformation of the G-quadruplex from antiparallel to hybrid-type. By tuning the ratio of Na(+)/K(+), the enantioselectivity of the Diels-Alder reaction could be switchable and shows much more sensitive to K(+) than to Na(+).

matricaria chamomilla is a medicinal plant that is widely cultivated in salt affected soils. this investigation was undertaken to study the effect of nacl concentration on germination, and the physiological, biochemical and growth characteristics of chamomile. seed germination and growth were studied at five nacl concentration levels (0, 40, 80, 120 and 190 mm nacl concentration). increasing th...

Ethanol intoxication resulted in high extent of lipid peroxidation, and reduction in antioxidant defenses (decreased GSH, GSH/GSSG ratio, and catalase, SOD and GPx activities) and (Na+/K+)-ATPase activity in kidney. Alpha-tocopherol treatment effectively protected kidney from ethanol induced oxidative challenge and improved renal (Na+/K+)-ATPase activity. Ethanol induced oxidative stress in the...

Genetic and physiological data establish that Arabidopsis AtHKT1 facilitates Na(+) homeostasis in planta and by this function modulates K(+) nutrient status. Mutations that disrupt AtHKT1 function suppress NaCl sensitivity of sos1-1 and sos2-2, as well as of sos3-1 seedlings grown in vitro and plants grown in controlled environmental conditions. hkt1 suppression of sos3-1 NaCl sensitivity is li...

Geopolymer paste is an innovative construction material which shall be produced by chemical action of inorganic molecules. It is a more environmentally friendly alternative to conventional Portland cement which is abundantly available worldwide. In this study, the influence of different alkaline activators (Na and K) on the mechanical and thermal behaviors of metakaolin-based geopolymer was inv...

Resealed human red blood cell ghosts were prepared to contain a range of ADP concentrations at fixed ATP concentrations and vice versa. ATP/ADP ratios ranging from approximately 0.2 to 50 were set and maintained (for up to 45 min) in this system. ATP and ADP concentrations were controlled by the addition of either a phosphoarginine- or phosphocreatine-based regenerating system. Ouabain-sensitiv...

Two methods of detecting early inapparent myocardial infarcts have been studied and their value in diagnostic practice compared. The better method proved to be the determination of the potassium to sodium ratio (ionic ratio) which falls in infarcted tissue within minutes of the onset of anoxia. The second method was nitro blue tetrazolium staining of gross sections of myocardium which revealed ...

in this study, the effects of long term use of urban wastewater (over 40 years) on soil salt content and related parameters were evaluated in the lands south of tehran. for this analysis, kriging methods were tested. according to the suitable model indices, ordinary kriging (ok) was suitable for ph, clay, na+, mg2+ and sodium adsorption ratio (sar) interpolation; log-normal kriging (log-normal ...

Tissue-distinct interactions of the Na+-K+-ATPase with Na+ and K+, independent of isoform-specific properties, were reported previously (A. G. Therien, N. B. Nestor, W. J. Ball, and R. Blostein. J. Biol. Chem. 271: 7104-7112, 1996). In this paper, we describe a detailed analysis of tissue-specific kinetics particularly relevant to regulation of pump activity by intracellular K+, namely K+ inhib...

Effects of diphenylhydantoins on (Na(+) + K(+))-ATPase activity in rat and cat brain microsomes were studied. 5,5-diphenylhydantoin (DPH) in concentrations of 5-20 mug ml(-1) produces an apparent stimulation of the rat brain (Na(+) + K(+))-activated ATPase of 55-65% in media containing 50 mM Na(+), 0.15 mM K(+), 3 mM Mg(++), and 3 mM ATP. No effects are found on the Mg-ATPase. At constant K(+) ...