We present prototype modules for a tracking detector consisting of multiple layers of 0.25
mm diameter scintillating fibers that are read out by linear arrays of silicon photomultipliers. The module ...production process is described and measurements of the key properties for both the fibers and the readout devices are shown. Five modules have been subjected to a 12
GeV/
c proton/pion testbeam at CERN. A spatial resolution of
50
μ
m
and light yields exceeding 20 detected photons per minimum ionizing particle have been achieved, at a tracking efficiency of more than 98.5%. Possible techniques for further improvement of the spatial resolution are discussed.
The beam-gas vertex (BGV) detector is an innovative instrument measuring noninvasively the transverse beam size in the Large Hadron Collider (LHC) using reconstructed tracks from beam-gas ...interactions. The BGV detector was installed in 2016 as part of the R&D for the High-Luminosity LHC project. It allows beam size measurements throughout the LHC acceleration cycle with high-intensity physics beams. A precision better than 2% with an integration time of less than 30 s is obtained on the average beam size measured, while the transverse size of individual proton bunches is measured with a resolution of 5% within 5 min. Particles emerging from beam-gas interactions in a specially developed gas volume along the beam direction are recorded by two tracking stations made of scintillating fibers. A scintillator trigger system selects, on-line, events with tracks originating from the interaction region. All the detector elements are located outside the beam vacuum pipe to simplify the design and minimize interference with the accelerated particle beam. The beam size measurement results presented here are based on the correlation between tracks originating from the same beam-gas interaction vertex.
Carcinoma of the gallbladder is a rare disease. Gallbladder carcinoma is detected in less than 1% of all gallstone operations. With the introduction of laparoscopic surgery and the higher acceptance ...of this technique, gallbladders are now removed much earlier than they used to be. With the increase of cholecystectomies, the diagnosis of unexpected gallbladder carcinoma became more frequent. We report on how to proceed in patients with a diagnosis of gallbladder carcinoma and discuss the additional problems that have arisen since laparoscopic cholecystectomy became established. From June 1990 to December 1999, we performed 6230 cholecystectomies in the surgical department of Moabit Hospital in Berlin. Of these, 42 (0.6%) were identified as carcinoma. There were 37 women and five men, and the mean age was 69 years. In 16 patients (39%), there was a preoperative suspicion of malignancy. In 26 patients (61%), malignancy was suspected intraoperatively or diagnosed postoperatively after pathologic examination of the resected gallbladder. In these patients, an open repeat operation was necessary in seven cases to achieve an adequate curative resection and staging. This involved additional liver bed resection and lymph node dissection of the hepatoduodenal ligament. Abdominal wall (port site) recurrence in the absence of distant metastasis was present only in two patients. We recommend removal using a bag in all gallbladders with wall thickening, irregularities, or scleroatrophic calcified gallbladder area. In stage Tis or T1, laparoscopic cholecystectomy is sufficient. In stage T2 and T3, we perform a repeat operation with liver bed resection and lymphadenectomy.
The AF‐4 gene on human chromosome 4q21 is involved in reciprocal translocations to the ALL‐1 gene on chromosome 11q23, which are associated with acute lymphoblastic leukaemias. A set of recombinant ...phage carrying genomic fragments for the coding region and flanking sequences of the AF‐4 gene were isolated. Phage inserts were assembled into four contigs with 21 exons, and an intron phase map was produced enabling the interpretation of translocation‐generated fusion proteins. The gene contains two alternative first exons, 1a and 1b, both including a translation initiation codon. The translocation breakpoint cluster region is flanked by exons 3 and 6 and two different polyadenylation signals were identified. Polyclonal antisera directed against three different portions of the AF‐4 protein were produced and used to detect a 116 kD protein in cellular extracts of human B‐lymphoblastoid and proB cell lines. In mitogen‐stimulated human peripheral blood mononuclear cells the AF‐4 antigen was predominantly located in the nucleus. The AF‐4 gene is a member of the AF‐4, LAF‐4 and FMR‐2 gene family. The members of this family encode serine‐proline‐rich proteins with properties of nuclear transcription factors. Comparison of AF‐4 protein coding sequences with the LAF‐4 and FMR‐2 sequences revealed five highly conserved domains of potential functional relevance.
The Beam Gas Vertex detector (BGV) is an innovative beam profile monitor based on the reconstruction of beam-gas interaction vertices which is being developed as part of the High Luminosity LHC ...project. Tracks are identified using several planes of scintillating fibres, located outside the beam vacuum chamber and perpendicular to the beam axis. The gas pressure in the interaction volume is adjusted such as to provide an adequate trigger rate, without disturbing the beam. A BGV demonstrator monitoring one of the two LHC beams was fully installed and commissioned in 2016. First data and beam size measurements show that the complete detector and data acquisition system is operating as expected. The BGV operating parameters are now being optimised and the reconstruction algorithms developed to produce accurate and fast reconstruction on a CPU farm in order to provide real time beam profile measurements to the LHC operators.
The Beam Gas Vertex detector (BGV) is an innovative beam profile monitor based on the reconstruction of beam-gas interaction vertices which is being developed as part of the High Luminosity LHC ...project. Tracks are identified using several planes of scintillating fibres, located outside the beam vacuum chamber and perpendicular to the beam axis. The gas pressure in the interaction volume is adjusted such as to provide an adequate trigger rate, without disturbing the beam. A BGV demonstrator monitoring one of the two LHC beams was fully installed and commissioned in 2016. First data and beam size measurements show that the complete detector and data acquisition system is operating as expected. The BGV operating parameters are now being optimised and the reconstruction algorithms developed to produce accurate and fast reconstruction on a CPU farm in order to provide real time beam profile measurements to the LHC operators.
The human ALL-1/MLL/HRX gene on chromosome 11q23 is the site of many locally clustered chromosomal alterations associated with several types of acute leukemias, including deletions, partial ...duplications and reciprocal translocations. Structurally variant proteins derived from an altered ALL-1 gene presumably make essential contributions to the malignant transformation of hematopoietic progenitor cells. The ALL-1 gene is spread over approximately 92 kb and consists of at least 37 exons. An exon/intron map including the position of the 3'-end of the gene and a detailed restriction map were produced and an updated map is presented. Data from other laboratories were incorporated where compatible. Exon/intron boundaries were sequenced and an intron-phase analysis was performed. The results are expected to contribute to a better understanding of those structural alterations of the gene that conserve the open reading frame and produce presumably oncogenic variants of the ALL-1 protein. They will also facilitate the rapid molecular diagnosis of structural alterations of this gene and the choice of therapeutic options. Mechanisms that may potentially account for the striking clustering of the translocation breakpoints in the breakpoint cluster region of the gene are discussed.
ZusammenfassungZur Optimierung der Auslegung von Turbomaschinen ist die exakte Kenntnis des in der Maschine vorliegenden Strömungsfeldes eine wesentliche Voraussetzung. Die sinnvolle Ergänzung von ...experimentellen Arbeiten durch numerische Untersuchungen kann das hierfür erforderliche Verständnis für die Strömungsverhältnisse liefern. Moderne Meßtechniken ermöglichen die Erfassung instationärer Strömungsvorgänge und liefern damit nicht nur einen detaillierten Einblick in die untersuchten Meßebenen, sondern erlauben zusätzlich die Kontrolle komplizierter Berechnungsverfahren. Die mit der Weiterentwicklung der Computer und der Berechnungsverfahren kontinuierlich wachsenden Möglichkeiten der numerischen Strömungssimulation erlauben nicht nur die Kontrolle von Meßergebnissen, sondern gewähren zusätzlich einen Einblick in Strömungsvorgänge die meßtechnisch unzugänglich sind.Im Rahmen dieser Veröffentlichung wird die erfolgreiche Zusammenarbeit meßtechnischer und numerischer Untersuchungen einer Turbomaschine am Beispiel der Strömungsuntersuchung in einem hydrodynamischen Wandler dokumentiert.Zwischen den beiden Laufrädern des Wandlers wurden die zeitlich veränderlichen Druckverläufe gemessen. Kern des hierzu eingesetzten Meßsystems bildet eine als Ersatz für die empfindlichen Heißfilmsonden entwickelte miniaturisierte, schnell ansprechende Drucksonde. Parallel dazu wurde ein Finite-Volumen-Verfahren entwickelt, mit dem die inkompressible, dreidimensionale, instationäre Strömung in relativ zueinander bewegten Komponenten einer Turbomaschine berechnet werden kann. Mit diesem Verfahren ist die Strömung im Bereich der Pumpe und der Turbine simuliert worden.Der Vergleich der berechneten Drehmomente mit den Werten einer gemessenen Kennlinie sowie die Gegenüberstellung der berechneten Meridian-und Umfangsgeschwindigkeiten mit den entsprechenden gemessenen Werten zeigen gute Übereinstimmungen. Rechnung und Messung in der Ebene zwischen Pumpe und Turbine beweisen, daß die experimentelle Analyse der Pumpenströmung durch die Computerberechnung ersetzt werden darf.
A silicon photomultiplier (SiPM) array has been developed at FBK-irst Piemonte C., Nucl. Instrum. Methods A,
568 (2006) 224; Piemonte C. et al., IEEE Trans. Nucl. Sci.,
54 (2007) 236 having 32 ...channels and a dimension of
8.0
×
1.1
mm
2
. Each 250 μm wide channel is subdivided into
5
×
22
rectangularly arranged pixels. These sensors are developed to read out a modular high resolution scintillating fiber tracker. Key properties like breakdown voltage, gain and photon detection efficiency (PDE) are found to be homogeneous over all 32 channels of an SiPM array. This could make scintillating fiber trackers with SiPM array readout a promising alternative to available tracker technologies, if noise properties and the PDE are improved.
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