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Das ursprunglich fur die Ascheanteilsbestimmung in Braunkohle entwickelte Komplexe Radiometrische Analysen-system KRAS-2“, das auf der Grundlage des Zwei-Gammaenergie-Transmissionsverfahrens arbeitet und zur Eliminierung von Dichte- und Schichtdickenschwankungen des Meβgutes ein auf einem Mikroprozessor basierendes Datenver-arbeitungssystem enthalt, wurde hinsichtlich seiner Eignung fur die Messung des Anteils mineralischer Beimengungen in Erntegutern getestet. Die on-line-Messungen an einer Kartoffel-Einlagerungsstrecke einer Praxis-Anlage wahrend der Erntekampagne bestatigten die Ergebnisse aus vorausgegangenen Abschatzungen und Laborexperimenten, daβ der Beimengungsanteil mit einem Fehler von unter 3 Masseprozent bestimmbar ist.The 2-energy transmission gauge KRAS-2 applying a microprocessorbased on-line date processing for eliminating surface density variations - originally developed for ash content determination in raw lignite - has been checked for its applicability to measuring the content of mineral substance in crop materials. On-line measurements at one of the entrance conveyor belts of a potatoe store facility during the harvesting campaign proved, that the soil content can be measured with an accuracy of better than 3 mass-% as required in practice.

Mit einem Endfenster-Zahlrohr warden fur die Betastrahlung des 144Pr (Maximalenergie 3 MeV, im Gleichgewicht mit 144Ce) fur 12 Absorberelemente (Beryllium bis Blei) die Massenschwachungskoeffizienten bestimmt. Die gefundene Kernladungszahlabhangigkeit laβt sich fur Kernladungszahlen oberhalb etwa 13 innerhalb des Meβfehlers (von 1 bis 2%) durch eine lineare Funktion darstellen. Anzahl der untersuchten Absorberelemente sowie ihre Lage innerhalb der 5. und 6. Periode schlieβen aus, daβ eine mit den Perioden des Systems der chemischen Elemente konform gehende Abhungigkeit des Massenschwachungskoeffizienten von der Kernladungszahl, wie sie beispielsweise von Crowther 1906 gemessen wurde, auftritt.

Migration of lymphocytes into inflammatory sites requires their adhesion to the vascular endothelium and subendothelial extracellular matrix (ECM). The ensuing penetration of the ECM is associated with the expression of ECM-degrading enzymes, such as endo-beta-D glucuronidase (heparanase), which cleaves heparan sulfate (HS) proteoglycans. We now report that, depending on the local pH, a mammalian heparanase can function either as an enzyme or as an adhesion molecule. At relatively acidified pH conditions, heparanase performs as an enzyme, degrading HS. In contrast, at the hydrogen ion concentration of a quiescent tissue, heparanase binds specifically to HS molecules without degrading them, and thereby anchors CD4+ human T lymphocytes. Thus, the local state of a tissue can regulate the activities of heparanase and can determine whether the molecule will function as an enzyme or as a proadhesive molecule.

Bovine aortic endothelial cells contain Ca2+-dependent tissue-type transglutaminase. Its activity in these cells was high, with apparent Km and Vmax. values with respect to putrescine of 0.203 mM and 18.5 nmol/min per mg of protein, and its activity was inhibited by the three competitive inhibitors dansylcadaverine, spermine and methylamine. The molecular mass of endothelial cell transglutaminase estimated by gel filtration chromatography was 88 kDa and it was immunoprecipitated by rabbit monospecific antiserum raised against rat liver transglutaminase. Its enzymic activity rose when the cell cultures reached confluence, and was further increased when their proliferation was arrested (synchronized at G0/G1 phase). Most of the enzymic activity was found in the 15,000 g soluble fraction, with only 4-22% of the activity found in the particulate fraction, depending on the state of cell proliferation. Examination of these cellular fractions by SDS/polyacrylamide-gel electrophoresis and immunoblotting revealed that at confluence endothelial cells have accumulated transglutaminase antigen in their 15,000 g particulate fraction. A series of experiments demonstrated the existence of a latent transglutaminase form in non-proliferating cells, and suggested that this might involve the formation of an inhibitory complex. Treatment of cell lysates and the 15,000 g particulate fraction with high salt concentration showed a significant increase in transglutaminase activity. Mixing experiments using the 100,000 g particulate fraction or purified rat liver transglutaminase on one hand and the cytosolic fraction on the other showed dose-dependent inhibition of the transglutaminase activity of the latter. It is concluded that endothelial cells contain a particulate fraction-residing inhibitor of transglutaminase which interacts via ionic interaction with the enzyme.

Mit einem Glockenzahlrohr wurden die Transmissionskurven von 10 Absorberelementen (Al bis Pb) fur die Belastrahlung des 144Ce-144Pr in unterschiedlichen Meβanordnungen bestimmt. Es zeigen sich Gesetzmaβigkeiten fur die Abhangigkeit des Massenschwachungskoeffizienten von zwei maβgeblichen geometrischen Parametern, das sind der Raumwinkel der Einfallsgeometrie und der Raumwinkel der Detektionsgeometrie. Die wenigen bisher vorliegenden Meβwerte anderer Autoren lassen sich meist zwangslos in die gefundenen Geselzmaβigkeiten einordnen.Die in vorangegangenen Mitteilungen [1,2] diskutierten Periodizitaten in der Kernladungszahlabhangigkeit des Massenschwachungskoeffizienten konnten in keiner der untersuchten Geometrien nachgewiesen werden.

Combining the 60 keV scatter-transmission signal (s. d. about 4 wt % ash) with the 660 keV transmission signal thus eliminating residual influences of thickness and density variations the s. d. can be reduced to about 2 … 3 wt % ash. A gauge developed for on-line determination of ash content based on the 2-energy narrow beam transmission method using a micro-processor for data processing was tested at the main conveyour belt of a power station giving a s. d. of about 5 wt % ash with coal thickness variations between 5 and 40 cm.