Effective Background Shield for Low Activity Measurements

1960 ◽  
Vol 31 (5) ◽  
pp. 573-574 ◽  
Author(s):  
Antti P. U. Vuorinen
Keyword(s):  
Activity Measurements ◽  
Low Activity

scholarly journals Improving radioactive contaminant identification through the analysis of delayed coincidences with an $$\alpha $$-spectrometer

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
G. Baccolo ◽  
A. Barresi ◽  
M. Beretta ◽  
D. Chiesa ◽  
M. Nastasi ◽  
...  
Keyword(s):  
Pure Copper ◽  
Rare Event ◽  
Radioactive Decay ◽  
Time Correlation ◽  
Impurity Level ◽  
Analysis Tool ◽  
Activity Measurements ◽  
Analysis Strategies ◽  
Alpha Spectrometer ◽  
Low Activity

AbstractIn the framework of rare event searches, the identification of radioactive contaminants in ultra-pure samples is a challenging task, because the signal is often at the same level of the instrumental background. This is a rather common situation for $$\alpha $$ α -spectrometers and other detectors used for low-activity measurements. In order to obtain the target sensitivity without extending the data taking live-time, analysis strategies that highlight the presence of the signal sought should be developed. In this paper, we show how to improve the contaminant tagging capability relying on the time-correlation of radioactive decay sequences. We validate the proposed technique by measuring the impurity level of both contaminated and ultra-pure copper samples, demonstrating the potential of this analysis tool in disentangling different background sources and providing an effective way to mitigate their impact in rare event searches.

New records on low activity measurements with neutron activation analysis

1998 ◽  
Vol 61 (3) ◽  
pp. 176-179 ◽  
Author(s):  
Th. Goldbrunner ◽  
G. Angloher ◽  
F.v. Feilitzsch ◽  
R.v. Hentig ◽  
M. Neff
Keyword(s):  
Neutron Activation Analysis ◽  
Activation Analysis ◽  
Neutron Activation ◽  
New Records ◽  
Activity Measurements ◽  
Low Activity

Influence of Moderate and Strenuous Daily Physical Activity on Fibrinolytic Activity of Blood: Possibility of Plasminogen Activator Stores Depletion

1979 ◽  
Vol 41 (04) ◽  
pp. 745-755 ◽  
Author(s):  
Dušan Keber ◽  
Mojca Stegnar ◽  
Irena Keber ◽  
Bojan Accetto
Keyword(s):  
Physical Activity ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Regular Physical Activity ◽  
Clot Lysis ◽  
Moderate Activity ◽  
Lysis Time ◽  
Strenuous Activity ◽  
Activity Measurements ◽  
Clot Lysis Time

SummaryFibrinolysis was studied in 10 alpinists during regular physical activity of different intensity. Blood was sampled at rest and after exposure to submaximal workload on the treadmill on three occasions: before and after 6 months physical conditioning (moderate physical activity), and after 6 weeks of an alpinistic expedition (strenuous physical activity). Measurements included submaximal working capacity, fibrinogen, euglobulin clot lysis time (ELT), whole plasma clot lysis time, and estimations derived from ELT - percent increase in fibrinolytic activity after exercise (RFS), and absolute increase in fibrinolytic activity after exercise (PAR).Regular moderate activity increased the resting level of ELT, but strenuous activity decreased is. After each treadmill testing, a marked increase in fibrinolytic activity was observed. RFS was unaltered at all three testings. PAR increased after moderate activity, but decreased after strenuous activity.The results indicate that regular physical activity can lead from enhanced to decreased resting activity of plasminogen activator in blood. It is presumed that increased release of activator during prolonged stress causes partial depletion of endothelial stores with the consequence of decreased activator activity in the blood.

A New Method for Plasminogen Standardization

1968 ◽  
Vol 20 (03/04) ◽  
pp. 548-554
Author(s):  
J Gajewski ◽  
G Markus
Keyword(s):  
Proteolytic Activity ◽  
Specific Activity ◽  
Molar Ratio ◽  
Sharp Transition ◽  
Equivalence Point ◽  
Constant Amount ◽  
Residual Level ◽  
Activity Measurements ◽  
Complete Saturation ◽  
Human Plasminogen

SummaryA method for the standardization of human plasminogen is proposed, based on the stoichiometric interaction between plasminogen and streptokinase, resulting in inhibition of proteolytic activity. Activation of a constant amount of plasminogen with increasing amounts of streptokinase yields linearly decreasing activities, as a function of streptokinase, with a sharp transition to a constant residual level. The point of transition corresponds to complete saturation of plasmin with streptokinase in a 1:1 molar ratio, and is therefore a measure of the amount of plasminogen present initially, in terms of streptokinase equivalents. The equivalence point is independent of the kind of protein substrate used, buffer, pH, length of digestion and, within limits, temperature. The method, therefore, is not subject to the variations commonly encountered in the usual determination based on specific activity measurements.

A Comparison of the in Vitro and in Vivo Thrombogenic Activity of Factor IX Concentrates Using Stasis (Wessler) and Non-Stasis Rabbit Models

1980 ◽  
Vol 44 (02) ◽  
pp. 081-086 ◽  
Author(s):  
C V Prowse ◽  
A E Williams
Keyword(s):  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Factor Ix ◽  
Coagulation System ◽  
In Vitro Tests ◽  
Clinical Use ◽  
Low Activity

SummaryThe thrombogenic effects of selected factor IX concentrates were evaluated in two rabbit models; the Wessler stasis model and a novel non-stasis model. Concentrates active in either the NAPTT or TGt50 in vitro tests of potential thrombogenicity, or both, caused thrombus formation in the Wessler technique and activation of the coagulation system in the non-stasis model. A concentrate with low activity in both in vitro tests did not have thrombogenic effects in vivo, at the chosen dose. Results in the non-stasis model suggested that the thrombogenic effects of factor IX concentrates may occur by at least two mechanisms. A concentrate prepared from platelet-rich plasma and a pyrogenic concentrate were also tested and found to have no thrombogenic effect in vivo.These studies justify the use of the NAPTT and TGt50 in vitro tests for the screening of factor IX concentrates prior to clinical use.

The Measurement of Heparin and Other Therapeutic Sufphated Polysaccharides in Plasma, Serum and Urine

1985 ◽  
Vol 54 (03) ◽  
pp. 630-634 ◽  
Author(s):  
J Dawes ◽  
C V Prowse ◽  
D D Pepper
Keyword(s):  
Biological Fluids ◽  
Anticoagulant Activity ◽  
Dose Range ◽  
Plasma Concentrations ◽  
Heparin Therapy ◽  
Competitive Binding Assay ◽  
First Order Kinetics ◽  
Activity Measurements ◽  
Heparin Activity ◽  
Dose Dependent

SummaryThe competitive binding assay described will specifically and accurately measure concentrations of administered heparin in biological fluids with a sensitivity of 60 ng ml-1. Neither endogenous glycosaminoglycans, nor plasma proteins such as ATIII and PF4 interfere in the assay. Semi-synthetic highly sulphated heparinoids and LMW heparin can also be measured. Using this assay heparin clearance followed simple first-order kinetics over the dose range 100-5,000 units, but the half-life was strongly dose-dependent. There was good correlation with heparin activity measurements by APTT and anti-Xa clotting assays. Plasma concentrations were measurable for at least 5 h following subcutaneous injection of 10,000 units of heparin. Excretion in the urine could be followed after all but the lowest intravenous dose. This assay, used in conjunction with measurements of heparin anticoagulant activity, will be valuable in the elucidation of mechanisms of action of heparin and the heparinoids, and in the assessment and management of problems related to heparin therapy.

Separation of Heparin into Subtractions by DEAE-Cellulose Chromatography

1979 ◽  
Vol 42 (05) ◽  
pp. 1452-1459 ◽  
Author(s):  
Robert H Yue ◽  
Toby Starr ◽  
Menard M Gertler
Keyword(s):  
High Activity ◽  
Uronic Acid ◽  
Deae Cellulose ◽  
Exchange Chromatography ◽  
Net Charge ◽  
Uronic Acid Content ◽  
Successful Separation ◽  
Salt Gradient ◽  
Structure And Activity ◽  
Low Activity

SummaryCommercial porcine heparin can be separated into three distinct subtractions by using DEAE-cellulose chromatography and a stepped salt gradient. Gram quantities of heparin can be fractionated by this technique. All three heparin subtractions can accelerate the inhibition of thrombin by antithrombin III with different efficiency. The specific activities of the high activity heparin, intermediate activity heparin and low activity heparin are 228 units/mg, 142 units/mg and 95 units/mg, respectively. Both the uronic acid content and the quantity of N-SO4 for all three heparin subfractions have been evaluated. The high activity heparin has the lowest uronic acid and N-SO4 content. The successful separation of commercial heparin into three distinct subfractions by means of ion-exchange chromatography suggests that the net charge on these three heparin components will serve as a model system in the elucidation of the structure and activity relationship to the biological function of heparin.

PENERAPAN STRATEGI MENJAWAB SECARA BERGANTIANBERPOLA LINGKARAN ROUND ROBIN UNTUKMENINGKATKAN HASIL BELAJAR PPKn SISWA KELAS VISDN 002 UKUI DUA KECAMATAN UKUI

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Diyan Pertiwi
Keyword(s):  
Student Learning ◽  
Learning Outcomes ◽  
Sixth Grade ◽  
Student Learning Outcomes ◽  
Round Robin ◽  
Class Action ◽  
Sixth Grade Students ◽  
Teachers And Students ◽  
Improve Student Learning ◽  
Low Activity

This study is a class action that aims to improve learning outcomes in subjects PPKn sixth grade students of SDN 002 Ukui Dua. This research is motivated by the low activity and low teacher and student learning outcomes in subjects PPKn. The problem of this study is whether the implementation of a strategy to answer alternately patterned circle round robin can improve student learning outcomes in subjects PPKn in the sixth grade SDN 002 Ukui Dua? This PPKn was conducted over two cycles. Data collection techniques in this research using collection observation techniques, achievement test, and documentation. Techniques of analysis in this study is an analysis of the activities of teachers and students and learning outcomes in subjects PPKn sixth grade students SDN 02 Ukui Dua Kecamatant Ukui. The result showed that the activity of teachers has increased. At the first meeting of the first cycle of 41% was obtained with Simply Perfect category and the second meeting reached 55% with the category Fairly Perfect. In the second cycle 3 meeting to reach 75% by the Perfect category and the 4th meeting of the second cycle reaches 85% with the Perfect category. While the activity of students has increased. At the first meeting of the first cycle reaches 51% with the category Fairly Perfect and the second meeting with the percentage of 66% to the category Perfect. After the second cycle of the third meeting with a percentage of 75% with the Perfect category while in attendance for-4 with the percentage of 94% to the category of Most Perfect. Learning outcomes of students also increased from the previous students who achieve KKM only 8 votes with a percentage (45%) after the first cycle an increase in students worth over KKM which reached 14 people with a percentage of 70%. Cycle II students who achieve KKM 17 (85%).

Pool Boiling on a Surface Supplied by Low Activity Sites

1997 ◽  
Vol 28 (4-6) ◽  
pp. 255-258
Author(s):  
V. V. Privezentsev ◽  
A. V. Carzhavin
Keyword(s):  
Pool Boiling ◽  
Low Activity
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