The Straw Tube Tracker of the PANDA experiment Braghieri, A.; Boca, G.L.; Costanza, S. ...
2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC),
2009-Oct.
Conference Proceeding
The PANDA experiment will investigate many aspects of particle and nuclear physics. This will be done by using the excellent quality antiproton beam that will be provided at the HESR storage ring, ...under construction as a part of the FAIR facility at Darmstadt, Germany. The experimental apparatus will be a fixed target detector with a central and a forward spectrometer. The PANDA central tracker is a key element of the experiment; it will provide information about decay vertices, momenta and charged particle species emitted after antiproton annihilation. Two possibilities are presently under study for this detector. The Straw Tube Tracker option will be illustrated together with experimental results of the R&D phase.
Zusammenfassung
Hintergrund
Tumorprothesen werden mit guten Langzeitergebnissen bei Kindern und Jugendlichen mit Knochentumoren implantiert und ermöglichen meist einen langfristigen ...Extremitätenerhalt. Ebenso finden 3‑D-gedruckte Individualimplantate zunehmend Anwendung.
Fragestellung
Mit diesem Beitrag wird eine Übersicht zu kindlichen und jugendlichen Knochentumoren und deren chirurgischer Behandlung gegeben. Aufgrund der Verteilungshäufigkeit der kindlichen und jugendlichen Knochentumoren mit einer Häufung im Bereich der unteren Extremität liegt der Schwerpunkt dieses Beitrags auf diesem Bereich.
Methodik
Es erfolgte die systematische Literaturrecherche bei PubMed sowie die Darstellung anhand der zentrumsinternen Erfahrungen.
Ergebnisse
Knochentumoren bei Kindern und Jugendlichen finden sich zumeist kniegelenknah. Die Verwendung von modularen Tumorprothesen stellt heutzutage die Therapie der Wahl dar, mit der in der Mehrzahl der Fälle ein langfristiger Extremitätenerhalt erreicht werden kann. Mittels Wachstumsprothesen kann bei jüngeren Kindern versucht werden, einer großen Beinlängendifferenz entgegenzuwirken. 3‑D-gedruckte Individualimplantate kommen zunehmend zum Einsatz. Generell haben Tumorprothesen eine höhere Komplikationsrate als primäre Endoprothesen. Die am häufigsten auftretenden Komplikationen und daraus folgende Revisionseingriffe im Langzeit-Follow-up sind periprothetische Infektionen, Prothesenverschleiß und aseptische Lockerungen.
The modern study of comparative animal behavior represents a marriage, and like all such unions, it has incorporated something borrowed, something new, and something old (as far as something blue is ...concerned, well no marriage is perfect). What's borrowed is that the scientific study of animal behavior was made possible by the synthesis of principles and techniques from two well-established fields: zoology and psychology. What's new is that, as an objective discipline, animal behavior is one of the youngest branches of the behavioral sciences. But paradoxically, and this is what's old, observations of animal behavior undoubtedly predate the evolutionary origin of human beings.
Fragmentation reactions with intermediate-energy heavy-ion beams exhibit a wide range of reaction mechanisms, ranging from direct reactions to statistical processes. We examine this transition by ...measuring the relative population of excited states in several sd-shell nuclei produced by fragmentation with the number of removed nucleons ranging from two to sixteen. The two-nucleon removal is consistent with a non-dissipative process whereas the removal of more than five nucleons appears to be mainly statistical.
In 1994, the Food and Agriculture Organization undertook to revitalise its activities in the control of transboundary animal disease by establishing a new special programme known as the Emergency ...Prevention System (EMPRES) against transboundary animal and plant pests and diseases. The emphasis of the EMPRES livestock component is placed on pre-empting outbreaks and losses experienced by agriculture through the enhancement of local capacity to detect and react rapidly to plague events. EMPRES concentrates on the co-ordination of the Global Rinderpest Eradication Programme--a time-bound eradication programme--whilst addressing the progressive control of the most serious epidemic diseases within a broad framework of emergency preparedness. Programme activities are discussed in relation to early warning, early reaction, facilitating research and co-ordination. In addition to rinderpest, particular attention has been paid to contagious bovine pleuropneumonia, a re-emerging disease in Africa targeted for strategic attention, and foot and mouth disease, for which co-ordinated regional control in Latin America and South-East Asia has been initiated. Tactical responses to other disease emergencies such as African swine fever, classical swine fever (hog cholera), Rift Valley fever, peste des petits ruminants and lumpy skin disease are described.
Primary cultures of astrocytes from newborn rat brain showed evidence of a substrate-saturable process for glucose transport. The system shows a relatively high affinity for the substrate, with an ...apparent Km of approximately 1 mM. Maintenance of the cells in medium containing thyroid-hormone-free serum for 3, 6, or 9 days resulted in significantly reduced rates of hexose transport. Addition of exogenous triiodothyronine to the transport incubation medium of these "hypothyroid" cells markedly increased the net rate of 2-deoxyglucose uptake within 60 s to values equal to or above those of control cultures (cells maintained in normal serum). These findings support a key role for thyroid hormone in the transport of glucose across plasma membranes of brain cells and demonstrate the presence of this regulatory system in astrocytes.
RNA polymerase has been solubilized from whole cell homogenates of the mouse myeloma tumor, MOPC 315. Four forms of the solubilized enzyme have been isolated by ion exchange chromatography and ...designated I, II, IIIa, and IIIb. The enzymes appear analogous to the Class I, II, and III RNA polymerases defined in other eukaryotic systems. Ionic strength optima, metal ion effects, α-amanitin sensitivities, and relative activities with polyd(A-T) and calf thymus DNA templates are different for Class I, II, and III RNA polymerases, but are identical for IIIa and IIIb. For the Class I and Class II enzymes ionic strength optima occur, respectively, at 0.05 and 0.09 m ammonium sulfate with either calf thymus DNA or polyd(A-T) as template. By contrast, the ionic strength activation profiles for Class III RNA polymerases with calf thymus DNA template are biphasic with polytima at 0.055 and 0.17 m ammonium sulfate; but with polyd(A-T) the profiles are monophasic with optima at 0.055 m. Although RNA polymerase I is completely resistant to α-amanitin at concentrations up to 400 µg per ml, RNA polymerases II and III can both be inhibited completely by the toxin. However, the sensitivity of RNA polymerase II (50% inhibition at 0.025 µg per ml) is much greater than that of the Class III RNA polymerases (50% inhibition at 20 µg per ml). Furthermore, the polyd(A-T) to calf thymus DNA activity ratios are considerably greater for the Class III RNA polymerases than for RNA polymerases I and II. By measuring RNA polymerase activity in DEAE-Sephadex fractions at α-amanitin concentrations just sufficient to inhibit RNA polympolymerase II and in the presence of polyd(A-T) RNA polymerase III activity has been detected in all tissues examined.
When the amounts of the different enzymes were measured in subcellular fractions of myeloma cells, RNA polymerase I was found predominantly in the nucleolar fraction, II and IIIa predominantly in the nucleoplasmic fraction, and IIIb predominantly in the cytoplasmic fraction. This latter observation raises the possibility that this enzyme may be of cytoplasmic origin.
Cellular levels of the RNA polymerases have been compared in MOPC 315 tissues and in normal tissues under various physiological conditions. Levels of Enzymes I and III are increased in the myeloma relative to calf thymus, mouse liver, and mouse spleen, and are increased in liver and spleen from tumor-bearing mice and younger (6 weeks) mice relative to tumor-free mice and older mice (10 meeks), respectively. Levels of Enzyme II are more invariant under these circumstances. These data are discussed in terms of possible regulatory roles of the three enzyme classes.
The rates of U-14Cglutamine oxidation to 14CO2 were determined under a variety of experimental conditions using whole homogenates and dissociated cells from rat brain. The pattern of glutamine ...oxidation by homogenates differed from that by dissociated brain cells in several respects. The rates of glutamine oxidation by dissociated brain cells showed saturation kinetics with an apparent Km of 0.30 mM. Lineweaver-Burk plots of glutamine oxidation by homogenates revealed two linear segments with two apparent Km values (0.58 mM and 3.0 mM). In the presence of aminooxyacetate, however, the Lineweaver-Burk plots for homogenates were linear with a single Km of 0.47 mM. The oxidation of glutamine by homogenates was inhibited by both rotenone and antimycin A (80-85%), as were glutamate and glucose oxidation, suggesting that a significant amount of glutamine is oxidized via the tricarboxylic acid cycle. In the presence of aminooxyacetate, glutamine oxidation was inhibited less than 40%, whereas the oxidation of glutamate was inhibited 75%; in contrast, glucose oxidation was enhanced 50%. The rates of glutamine oxidation by homogenates were highest in the presence of high levels of potassium (50 mM) and low levels of sodium (2.5 mM). Varying ionic composition, however, had little or no effect on the rates of glutamine oxidation by dissociated brain cells. Measurements of glutamine oxidation by homogenates prepared from 2-, 10-, 15-, 25-, and 90-day-old rats revealed little or no age-dependent difference. In contrast, the oxidation by dissociated brain cells from 2-day-old animals was significantly less than that obtained for animals 10 days or older (7.76 vs. 15.6 nmol/h/mg).
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