scholarly journals Enhanced higher temperature (20–30 K) transport properties and irreversibility field in nano-Dy2O3 doped advanced internal Mg infiltration processed MgB2 composites

2014 ◽  
Vol 105 (11) ◽  
pp. 112603 ◽  
Author(s):  
G. Z. Li ◽  
M. D. Sumption ◽  
M. A. Rindfleisch ◽  
C. J. Thong ◽  
M. J. Tomsic ◽  
...  
Keyword(s):  
Transport Properties ◽  
Irreversibility Field ◽  
Higher Temperature ◽  
Mgb2 Composites ◽  
K Transport

scholarly journals The transition from HK to LK phenotype in the red cells of newborn genetically LK lambs.

1982 ◽  
Vol 79 (5) ◽  
pp. 893-915 ◽  
Author(s):  
E M Tucker ◽  
C E Smalley ◽  
J C Ellory ◽  
P B Dunham
Keyword(s):  
Transport Properties ◽  
Developmental Process ◽  
Fetal Hemoglobin ◽  
Kinetic Studies ◽  
Red Cells ◽  
Small Cells ◽  
Adult Hemoglobin ◽  
K Concentration ◽  
Cell Volumes ◽  
K Transport

Red cells from newborn lambs were separated into different age populations by centrifugation, and cells with fetal hemoglobin (Hb) were distinguished from those with adult Hb by an acid elution technique. Changes were followed during development in rates of K+ transport (active and passive), numbers of Na+/K+ pump sites per cell, cell volumes, and numbers of Lp and L1 antigen sites per cell. These changes were correlated with the percentage of cells with adult hemoglobin. (The Lp and L1 antigens are associated with K+ transport in that specific alloantibody against Lp, anti-Lp, stimulates active transport, and anti-L1 inhibits passive transport.) Active K+ transport decreased during development because of a decline in number of Na+/K+ pumps (from measurements of ouabain binding) and because of an alteration in the affinity of the pumps for intracellular K+ (from kinetic studies in which the intracellular K+ concentration was varied). Cells with fetal Hb had fewer Lp sites and were larger than cells with adult Hb. As transport properties changed, the number of Lp sites increased and continued to increase after all the cells had adult Hb Cells with fetal Hb had as many L1 sites as lamb cells with adult Hb, but the number of L1 sites was less than those found previously for adult sheep. A population of small cells with intermediate K+ concentration and intermediate numbers of Lp sites appeared soon after birth. The various points of evidence suggested that the developmental process leading to cells with adult transport properties was a gradual one and did not coincide precisely with the switch from fetal to adult Hb.

TRANSPORT PROPERTIES OF Ag-DOPED La0.7Ca0.3MnO3 THIN FILMS ON SILICON SUBSTRATE

2010 ◽  
Vol 24 (27) ◽  
pp. 5451-5456 ◽  
Author(s):  
H. C. JIANG ◽  
W. L. ZHANG ◽  
X. F. CAO ◽  
W. X. ZHANG ◽  
B. PENG
Keyword(s):  
Thin Films ◽  
Transition Temperature ◽  
Transport Properties ◽  
Silicon Substrate ◽  
Annealing Temperature ◽  
Rf Magnetron Sputtering ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Higher Temperature

Ag -doped La 0.7 Ca 0.3 MnO 3 (LCMO) films were prepared on silicon substrate by RF magnetron sputtering. The dependences of transport properties on annealing temperature were explored. It is shown that the resistivity of the samples decreases and the metal–insulator transition temperature shifts to higher temperature with the increase in annealing temperature. Two metal–insulator transition temperatures are presented in the R – T plots of Ag -doped LCMO films, which can be explained by the Ag 1+ substitution of La 3+ to form La 1-x Ag x MnO 3 compound. Compared with LCMO thin films, Ag -doping can observably improve the TM-I and decrease the resistivity of the samples.

scholarly journals K+ Transport by the OsHKT2;4 Transporter from Rice with Atypical Na+ Transport Properties and Competition in Permeation of K+ over Mg2+ and Ca2+ Ions

2011 ◽  
Vol 156 (3) ◽  
pp. 1493-1507 ◽  
Author(s):  
Tomoaki Horie ◽  
Dennis E. Brodsky ◽  
Alex Costa ◽  
Toshiyuki Kaneko ◽  
Fiorella Lo Schiavo ◽  
...  
Keyword(s):  
Transport Properties ◽  
Na Transport ◽  
K Transport

scholarly journals K+ transport properties of K+ channels in the plasma membrane of Vicia faba guard cells.

1988 ◽  
Vol 92 (5) ◽  
pp. 667-683 ◽  
Author(s):  
J I Schroeder
Keyword(s):  
Plasma Membrane ◽  
Transport Properties ◽  
Vicia Faba ◽  
Guard Cell ◽  
Guard Cells ◽  
Stomatal Opening ◽  
Whole Cell ◽  
K Channels ◽  
K Transport ◽  
K Currents

Electrical properties of the plasma membrane of guard cell protoplasts isolated from stomates of Vicia faba leaves were studied by application of the whole-cell configuration of the patch-clamp technique. The two types of K+ currents that have recently been identified in guard cells may allow efflux of K+ during stomatal closing, and uptake of K+ during stomatal opening (Schroeder et al., 1987). A detailed characterization of ion transport properties of the inward-rectifying (IK+,in) and the outward-rectifying (IK+,out) K+ conductance is presented here. The permeability ratios of IK+,in and IK+,out currents for K+ over monovalent alkali metal ions were determined. The resulting permeability sequences (PK+ greater than PRb+ greater than PNa+ greater than PLi+ much greater than PCs+) corresponded closely to the ion specificity of guard cell movements in V. faba. Neither K+ currents exhibited significant inactivation when K+ channels were activated for prolonged periods (greater than 10 min). The absence of inactivation may permit long durations of K+ fluxes, which occur during guard cell movements. Activation potentials of inward K+ currents were not shifted when external K+ concentrations were changed. This differs strongly from the behavior of inward-rectifying K+ channels in animal tissue. Blue light and fusicoccin induce hyperpolarization by stimulation of an electrogenic pump. From slow-whole-cell recordings it was concluded that electrogenic pumps require cytoplasmic substrates for full activation and that the magnitude of the pump current is sufficient to drive K+ uptake through IK+,in channels. First, direct evidence was gained for the hypothesis that IK+,in channels are a molecular pathway for K+ accumulation by the finding that IK+,in was blocked by Al3+ ions, which are known to inhibit stomatal opening but not closing. The results presented in this study strongly support a prominent role for IK+,in and IK+,out channels in K+ transport across the plasma membrane of guard cells.

scholarly journals Cytodifferentiation and Membrane Transport Properties in LK Sheep Red Cells

1966 ◽  
Vol 50 (2) ◽  
pp. 379-390 ◽  
Author(s):  
Ping Lee ◽  
Anna Woo ◽  
D. C. Tosteson
Keyword(s):  
Transport Properties ◽  
Membrane Transport ◽  
Gradient Centrifugation ◽  
Massive Bleeding ◽  
Massive Hemorrhage ◽  
Red Cells ◽  
Density Fractions ◽  
Before And After ◽  
Genetically Determined ◽  
K Transport

Young cells produced in LK sheep during rapid hematopoiesis after massive hemorrhage contain more K than the cells which are normally released into the circulation. The K content in these new cells falls to that characteristic of mature LK cells after a few days in the circulation. K transport properties in young and old cells before and after massive bleeding were studied. Young and old cells were separated by means of a density gradient centrifugation technique. Evidence showing that younger cells are found in the lower density fractions is presented. Active transport of K in the lightest fraction as measured by strophanthidin-sensitive influx was four to five times greater in red cells drawn 6 days after massive bleeding while the K leak as measured by strophanthidin-insensitive influx was only slightly larger. No change after bleeding was observed in older cells which had been present in the circulation prior to the hemorrhage. It is concluded that the high K content of young cells produced in LK sheep after bleeding is due to temporary retention of membrane K transport properties characteristic of HK cells. Thus, genetically determined modification of membrane transport properties has been shown to occur in nondividing circulating red cells.

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