The Effect of Activator Concentration on the Infrared-Sensitive Phosphor, Strontium Sulfide—Samarium, Europium1

1948 ◽  
Vol 70 (1) ◽  
pp. 401-406 ◽  
Author(s):  
Kenneth F. Stripp ◽  
Roland Ward
Keyword(s):  
Activator Concentration ◽  
Strontium Sulfide

Studies on Activator Formation in Human Plasma with Streptokinase

1973 ◽  
Vol 30 (02) ◽  
pp. 381-392
Author(s):  
M Martin ◽  
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Mass Action ◽  
Activator Concentration ◽  
Kinetic Effect ◽  
Mass Action Law

SummaryThe plasminogen-streptokinase complex called “activator” was present in diluted plasma in the form of a largely dissociated mixture. More than ⅞ of the streptokinase and plasminogen molecules were available for further activator formation.The activator is probably a dissociated complex of the formulaStreptokinase + Plasminogen ⇄ Activator.The fact that an increase in activator concentration by x times is obtained by multiplying either the streptokinase content by the factor y or the plasminogen concentration by the same factor y would point to a kinetic effect along the lines of the mass action law.

Arterio-Venous Differences in the Components of the Fibrinolytic Enzyme System

1966 ◽  
Vol 16 (01/02) ◽  
pp. 032-037 ◽  
Author(s):  
D Ogston ◽  
C. M Ogston ◽  
N. B Bennett
Keyword(s):  
Plasminogen Activator ◽  
Enzyme System ◽  
Venous Blood ◽  
Fibrinolytic Enzyme ◽  
Blood Levels ◽  
Activator Concentration ◽  
Blood Samples ◽  
Arterial Blood ◽  
Male Subjects

Summary1. The concentration of the major components of the fibrinolytic enzyme system was compared in venous and arterial blood samples from male subjects.2. The plasminogen activator concentration was higher in venous blood and the arterio-venous difference increased as its concentration rose, but the ratio of the arterial to venous level remained constant.3. No arterio-venous difference was found for anti-urokinase activity, antiplasmin, plasminogen and fibrinogen.4. It is concluded that venous blood determinations of the components of the fibrinolytic enzyme system reflect satisfactorily arterial blood levels.

scholarly journals Regulation of human neutrophil aggregation: comparable latent times, activator sensitivities, and exponential decay in aggregability for FMLP, platelet-activating factor, and leukotriene B4

Blood ◽  
1993 ◽  
Vol 82 (11) ◽  
pp. 3460-3468 ◽  
Author(s):  
YP Rochon ◽  
MM Frojmovic
Keyword(s):  
Platelet Activating Factor ◽  
Leukotriene B4 ◽  
Variable Cross ◽  
Activator Concentration ◽  
Direct Measurements ◽  
Formyl Peptide ◽  
Activated Neutrophils ◽  
Neutrophil Aggregation ◽  
Protein Kinase C Activation

Abstract We have recently described a flow cytometry technique, whose sensitivity allows direct measurements of latent times before the onset of aggregation, and of rates, maximal extents, and reversibility of aggregation (J Leuk Biol 50:434, 1991). We report here that activators which stimulate sustained cellular signaling associated with increases in intracellular calcium (ionomycin) or protein kinase C activation (phorbol myristate acetate, PMA) cause complete (> or = 98%) and irreversible neutrophil aggregation, with latent times for the onset of aggregation inversely proportional to the activator concentration. In contrast, the receptor-specific activators leukotriene B4 (LTB4), formyl peptide FMLP, and platelet-activating factor (PAF) gave only partial and reversible aggregatory responses, limited by the following similar properties: latent times of 4.5 seconds +/- 1.5 seconds, independent of activator concentration; similar concentrations for onset of aggregation (approximately 1 nmol/L) that increased over a similar broad range of activator concentration, with one-half maximal rates of aggregation at 10 nmol/L to 30 nmol/L, corresponding to reported dissociation constant values; comparable limited recruitment and spontaneous reversibility of aggregation; absence of interactivator synergism; and similar exponential decays in activated cell stickiness (refractoriness), with t1/2 = 15 to 30 seconds. Variable cross- desensitization was seen between LTB4 and FMLP depending on donor and activator concentrations. In vivo, these properties are expected to provide localization of the aggregatory response, minimizing the otherwise detrimental effects of circulating activated neutrophils.

scholarly journals Luminescence in KI:Tl

1961 ◽  
Vol 14 (3) ◽  
pp. 368 ◽  
Author(s):  
JE Alderson ◽  
SE Williams
Keyword(s):  
Single Crystals ◽  
High Energy ◽  
Activator Concentration ◽  
Host Crystal ◽  
Absorption Bands ◽  
High Energy Side ◽  
Luminescence Efficiency ◽  
Vacuum Monochromator ◽  
Impurity Centre ◽  
Energy Side

Freshly cleaved single crystals of KI:TI containing various concentrations of Tl have been irradiated in a vacuum monochromator in the 2800-1100 A region at temper. atures between -140 and 45 �0. The relative luminescence efficiencies in the Tl absorption bands and the host crystal fundamental absorption show that energy is transferred from host crystal to impurity centre to produce luminescence at room temperatures. To the high energy side of a threshold, which appears to depend on activator concentration, the luminescence efficiency is superlinear above about 15 �0 for KI:Tl (0�0005%).

scholarly journals Characterization of Activated Carbon from Industrial Solid Waste Agar with a Different Activator Concentrations

Omni-Akuatika ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 77
Author(s):  
Khuril Zaqyyah ◽  
Sri Subekti ◽  
Mirni Lamid
Keyword(s):  
Activated Carbon ◽  
Carbon Content ◽  
Solid Waste ◽  
Active Carbon ◽  
Liquid Waste ◽  
Ash Content ◽  
Raw Material ◽  
Activator Concentration ◽  
Industrial Solid Waste ◽  
Randomized Design

Production of seaweed processing generates a huge amount of waste, either waste solid or liquid waste. For solid waste contains a lot of organic carbon derived from cellulose or hemicellulose. Therefore, the solid waste that has the potential as a raw material of activated carbon. This study aims to determine the characteristics of the activated carbon produced from solid waste agar and determine the optimal concentration of activator that produced the best characteristics of the activated carbon. The treatment used is a different activator concentration which is designed using completely randomized design (CRD) with five treatments and four replications. The results showed the five treatments are significant differences in the characteristics of the ash and pure active carbon content. This study shows that the manufacture of activated carbon industrial solid waste agar with a different activator concentration influence on the characteristics of the active carbon with ash content parameter and pure active carbon content. The concentration of activator that can provide the highest value of pure activated carbon is in P5 with a concentration of 6 M. Based on this study are advised to do further research on how to lower the ash content of the activated carbon from solid waste agar.

EFFECTS OF PLASMA KALLIKREIN AND BRADYKININ ON FIBRINOLYSIS AND THROMBOXANE PROSTACYKLIN FORMATION STUDIED IN MINIPIGS

1987 ◽  
Author(s):  
Nils Egberg ◽  
Krister Gréen ◽  
Jan Jacobsson ◽  
Ole Vester-gvist ◽  
Bjöm Wiman ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Fold Increase ◽  
Systemic Blood Pressure ◽  
Plasma Kallikrein ◽  
Activator Concentration ◽  
Systemic Blood ◽  
Pronounced Increase ◽  
Tissue Plasminogen ◽  
Activator Inhibitor

The effect of plasma kallikrein and bradykinin infusions into pigs on hemodynamic and hemostatic variables have been investigated. Both substances caused a pronounced decrease of the systemic blood pressure. The leucocyte count in periferal blood fell markedly, reaching a minimun within one hour after infusion of either of the substances.Signs that could be interpreted as a progressive disseminated intravascular coagulation with decrease of fibrinogen and platelet count was observed after kallikrein as well as bradykinin infusions. A pronounced increase of the plasma tissue plasminogen activator concentration followed both plasma kallikrein and bradykinin infusions. However, the peak concentration was found 5 minutes after bradykinin infusion but 60-120 minutes after kallikrein infusion, suggesting different mechanisms leading to the t-PA release. Concomittant with the maximun t-PA concentration there was a marked reduction of the plasminogen activator inhibitor (PAI) concentration. Three hours after drug infusions the PAI concentration was at or above preinfusion level. Kallikrein infusions caused a 10-20 fold increase of the urinary excretion of 2,3-dinor thromboxane B2 (metabolite of TxA2) and a 3-42 fold increase of 2,3-dinor-6-keto-PGFlalpha (metabolite of PGI2) excretion respectively. Corresponding data for bradykinin infusions were, 1.6-5 fold and 2-10 fold increases respectively. Possible links between leucocyte aggregation, prostanoid formation and fibrinolytic variables will be discussed.

The Measurement of Activator Concentration Using an X-Ray Fluorescence Method for Cr Ions in Al2O3 Crystals as an Example

2020 ◽  
Vol 63 (3) ◽  
pp. 416-420
Author(s):  
V. E. Asadchikov ◽  
B. S. Roshchin ◽  
V. A. Fedorov ◽  
A. D. Nuzhdin ◽  
V. A. Shishkov
Keyword(s):  
Fluorescence Method ◽  
Activator Concentration ◽  
X Ray
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