Alpha-particle spectrometry is the most frequently used technique for the activity determination of alpha emitters, such as radium, uranium, plutonium, americium and thorium in environmental samples. In this paper an extensive uncertainty budget is presented for a typical alpha-particle spectrometry measurement of the Ra activity concentration in drinking water. The most influential parameters ...

The alpha-amylases in the salivary glands of Lygus hesperus Knight and L. lineolaris (Palisot de Beauvois) were isolated and purified by ion exchange chromatography, and by isoelectric focusing, respectively. The alpha-amylase from L. hesperus had an isoelectric point (pI) of 6.25, and a pH optimum of 6.5. The specific activity of alpha-amylases in the salivary glands of L. hesperus was 1.2 U/m...

alpha-amylase is widely used as an industrial enzyme, and a therapeutic target for which inhibitors are designed. organic solvents are used to dissolve various compounds that would be studied as moderators of alpha-amylases, but they could themselves affect enzyme activity and stability. methanol, ethanol and propanol are simple alcohols that may be commonly used to this end, and their effect h...

Electroencephalography-correlated functional magnetic resonance imaging (EEG/fMRI) can be used to identify blood oxygen level-dependent (BOLD) signal changes associated with both physiological and pathological EEG events. Here, we implemented continuous and simultaneous EEG/fMRI to identify BOLD signal changes related to spontaneous power fluctuations in the alpha rhythm (8-12 Hz), the dominant...

Activation of plasma kallikrein arginine esterase activity by kaolin resulted in peak activity at 1 min of incubation and a 50% reduction in activity at 5 min in normal plasma, and 30% reduction in the plasma of patients with hereditary angioneurotic edema who lacked the C1 inactivator. The peak esterolytic activity was inhibited by soybean trypsin inhibitor whereas the 5 min activity was resis...

We examined the participation of the intraluteal levels of progesterone (P4) and prostaglandin F2 alpha (PGF2 alpha) in the induction of luteolysis by LH and its relationship with the induction of the 20 alpha-hydroxysteroid dehydrogenase activity (20 alpha-HSD). Subcutaneous administration of four doses of 10 microgram ovine LH (oLH) at 0800, 0900, 1000 and 1100 h on day 19 of pregnancy induce...

Comparatively analyses of electrophysiological correlates across species during evolution, alpha activity during brain maturation, and alpha activity in complex cognitive processes are presented to illustrate a new multidimensional "Cartesian System" brain function. The main features are: (1) The growth of the alpha activity during evolution, increase of alpha during cognitive processes, and de...

Macrophages exposed to receptor-recognized forms of alpha(2)-macroglobulin (alpha(2)M*) demonstrate increased DNA synthesis and cell division. In the current study, we have probed the role of cytosolic phospholipase A(2) (cPLA(2)) activity in the cellular response to alpha(2)M*. Ligation of the alpha(2)M* signaling receptor by alpha(2)M*, or its receptor binding fragment, increased cPLA(2) acti...

Changes in DNA polymerase alpha activity accompanying tissue development have been well established in several systems. In most cases, DNA polymerase alpha activity decreases with development. Here, we report observed changes in DNA polymerase alpha activity throughout embryonic chicken brain (ECB) development. The level of DNA polymerase alpha activity was found to gradually decrease by 60% (2...