Frequency- and voltage-dependent modification of drug-induced inhibition of maximal upstroke velocity of the action potential (Vmax) by the combined administration of two class I antiarrhythmic drugs was studied in canine Purkinje fibers, taking depression of upstroke velocity as an indicator of sodium channel blockade. The kinetics of onset of drug-induced Vmax depression and the time course o...

VMAX All Flash and the Adaptive Compression Engine offer more than simple capacity savings. Intelligent algorithms paired with hardware acceleration deliver enhanced performance and reduced compression overhead. This results in great overall system performance when inline compression is enabled and in use. May, 2017

The effects of 12-o-tetradecanoylphorbol-13-acetate (TPA) on isometric tension, unloaded shortening velocity determined using the slack test (Vmax), and phosphorylation of myosin light chain (MLC20) were investigated in intact and skinned muscle tissues of the rabbit mesenteric artery. In intact muscles exposed to 128 mM K+, the Vmax reached a maximum before the peak of the phasic component of ...

Fourteen healthy males (mean age 54.7 yr) described maximal flow volume curves after Air breathing (AB) and after inspiring 10 deep breaths of a mixture of 80% Helium/20% Oxygen (He/O2). Vmax 50% FVC as obtained from the AB curves was 3.11 +/- 1.27 lps, and this increased by 38.1 +/- 17%, with He/O2. The Vmax 50% He-O2/Air ratio was 1.32 +/- 0.17, while the V iso V was 1.1 +/- 0.35 liters (30.9...

BACKGROUND The serotonin transporter (5-HTT) is abundantly expressed in humans by the serotonin transporter gene SLC6A4 and removes serotonin (5-HT) from extracellular space. A blood-brain relationship between platelet and synaptosomal 5-HT reuptake has been suggested, but it is unknown today, if platelet 5-HT uptake can predict neural activation of human brain networks that are known to be und...

Bronchodilatation was produced in normal subjects by the inhalation of atropine, a parasympatholytic agent, and isoproterenol, a beta adrenergic stimulator. Density dependence of maximal expiratory flow (Vmax), expressed as a ratio of Vmax with an 80% helium-20% oxygen gas mixture to Vmax with air at isolung volumes, indicated that the predominant flow regimes across upstream airways changed di...

A model has been used to simulate potassium (K) uptake by wheat in a pot culture experiment. Three soils from India, namely Alfisol, Inceptisol and Vertisol, were differentially K exhausted by Sudan grass (Surghum vulgare var. Sudanensis) for a period of 280 days and were used to simulate potassium uptake by wheat (Triticum aestivum) and also to predict the amounts of K released or fixed during...

This study aimed to investigate whether ventilatory (VT) and respiratory compensation (RCT) thresholds could be derived from percentages of maximal running speed (Vmax). During the model building phase (1), VT & RCT of 31 competitive level athletes were identified with respiratory gas exchange. During the cross-validation phase (2), 20 subjects performed a treadmill test to identify Vmax and th...

Reports have suggested that the fast inward sodium current (INa) in cardiac tissues may be modulated by fl-adrenergic stimulation and that such modulation may affect conduction in the setting of myocardial ischemia and infarction. However, many of these studies have used dissociated myocytes or broken cell preparations, whose responses need not necessarily reflect those of syncytial preparation...

The rules that govern the relationships between enzymatic flux capacities (Vmax) and maximum physiological flux rates (v) at enzyme-catalyzed steps in pathways are poorly understood. We relate in vitro Vmax values with in vivo flux rates for glycogen phosphorylase, hexokinase, and phosphofructokinase, enzymes catalyzing nonequilibrium reactions, from a variety of muscle types in fishes, insects...