Tenascin-C (Tn-C) is a matricellular protein involved in the initial and intermediate stages of cell adhesion. The present study is the first undertaken to comparatively investigate Tn-C in ...neoplastic, non-neoplastic thyroid lesions and normal thyroid tissues. Forty-eight thyroid specimens were studied immunohistochemically using a monoclonal antibody against Tn-C. Immunohistochemistry was supplemented by RT-PCR analysis of the two Tn-C mRNA splice variants in 13 thyroid cancer cell lines. Normal and non-neoplastic tissues were devoid of Tn-C, as well as follicular neoplasms, Huerthle-cell and anaplastic carcinomas. Most papillary carcinomas showed a focally intensive extracellular staining, localized in the connective tissue stroma, whereas most medullary carcinomas showed a staining in the connective tissue but also in intracellular location mainly. RT-PCR analysis detected Tn-C mRNA in all thyroid cancer cell lines with prevalence of the large splice variant in all but the medullary line, characterized by a higher Tn-C
small:Tn-C
large ratio. In conclusion, Tn-C re-expression has been observed in papillary and medullary thyroid carcinomas with different staining patterns accompanied by the prevalence of different mRNA splice variants in cell cultures. It seems possible that Tn-C is rather synthesized by tumor cells than by activated stromal cells.
Performance of the micromegas detector in the CAST experiment Aune, S.; Dafni, T.; Fanourakis, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2007, Volume:
573, Issue:
1
Journal Article
Peer reviewed
Open access
The gaseous micromegas detector designed for the CERN Axion search experiment CAST, operated smoothly during Phase-I, which included the 2003 and 2004 running periods. It exhibited linear response in ...the energy range of interest (1–10
keV), good spatial sensitivity and energy resolution (15–19% FWHM at 5.9
keV) as well as remarkable stability. The detector's upgrade for the 2004 run, supported by the development of advanced offline analysis tools, improved the background rejection capability, leading to an average rate 5×10
−5
counts/s/cm
2/keV with 94% cut efficiency. Also, the origin of the detected background was studied with a Monte-Carlo simulation, using the GEANT4 package.
The use of the Micromegas technology for a new imaging system Fanourakis, G.K; Geralis, T; Kousouris, K ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2004, Volume:
527, Issue:
1-2
Journal Article
Peer reviewed
The Micromegas (Micromesh Gaseous) detector technology was developed by I. Giomataris and G. Charpak, in the mid 90s, for applications in the field of experimental Particle Physics. The most recent ...development is a novel Micromegas detector designed to detect photons of energies 1–10keV (X-ray range), for a discovery experiment of the hypothetical particles called axions, installed and currently taking data at CERN (the European Laboratory for Particle Research in Geneva). This detector has an X–Y readout capability of resolution less than 100μm, an energy resolution down to 14%, for this energy range, and an overall efficiency of 70%. With planned modifications, similar performances can be achieved for operation in the energy regime of the technetium gammas. This could lead to a novel γ-ray imaging device with spatial resolution in the submillimeter range. Initial results are presented obtained using the current detector with a parallel hole collimator to image thin capillary phantoms filled with a 99mTc water solution.
The T-REX project aims at developing novel readout techniques for Time Projection Chambers in experiments searching for rare events. The enhanced performance of the latest Micromegas readouts in ...issues like energy resolution, gain stability, homogeneity, material budget, combined with low background techniques, is opening new windows of opportunity for their application in this field. Here we review the latest results regarding the use and prospects of Micromegas readouts in axion physics (CAST and the future helioscope), as well as the R&D carried out within NEXT, to search for the neutrinoless double-beta decay.
Timing performance of a multi-pad PICOSEC-Micromegas detector prototype Aune, S.; Bortfeldt, J.; Brunbauer, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2021, Volume:
993, Issue:
C
Journal Article
Peer reviewed
Open access
The multi-pad PICOSEC-Micromegas is an improved detector prototype with a segmented anode, consisting of 19 hexagonal pads. Detailed studies are performed with data collected in a muon beam over four ...representative pads. We demonstrate that such a device, scalable to a larger area, provides excellent time resolution and detection efficiency. As expected from earlier single-cell device studies, we measure a time resolution of approximately 25 picoseconds for charged particles hitting near the anode pad centres, and up to 30 picoseconds at the pad edges. Here, we study in detail the effect of drift gap thickness non-uniformity on the timing performance and evaluate impact position based corrections to obtain a uniform timing response over the full detector coverage.
Micromegas technology is a promising candidate to replace Atlas forward muon chambers -tracking and trigger- for future HL-LHC upgrade of the experiment. The increase on background and pile-up event ...probability requires detector performances which are currently under studies in intensive RD activities. We studied performances of four different resistive Micromegas detectors with different read-out strip pitches. These chambers were tested using ~120 GeV momentum pions, at H6 CERN-SPS beam line in autumn 2010. For a strip pitch 500μm we measure a resolution of ~90 μm and a efficiency of ~ 98%. The track angle effect on the efficiency was also studied. Our results show that resistive techniques induce no degradation on the efficiency or resolution, with respect to the standard Micromegas. In some configuration the resistive coating is able to reduce the discharge currents at least by a factor of 100.
A Micromegas detector for the CAST experiment Andriamonje, S.; Aune, S.; Dafni, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Volume:
518, Issue:
1
Journal Article
Peer reviewed
Open access
A Micromegas detector has been mounted on the Cern Axion Solar Telescope experiment at CERN. Performance results of the detector, based on the fast period of data taken in November 2002 and in May ...2003, are presented. Preliminary results on efficiencies, background rejection and axion sensitivity are shown. A novel pixel Micromegas detector is being developed to be coupled to a focussing X-ray telescope.
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