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The muon detector of LHCb, which comprises 1368 multi-wire-proportional-chambers (MWPC) for a total area of 435 m2, is the largest instrument of its kind exposed to such a high-radiation environment. In nine years of operation, from 2010 until 2018, we did not observe appreciable signs of ageing of the detector in terms of reduced performance. However, during such a long period, many chamber gas gaps suffered from HV trips. Most of the trips were due to Malter-like effects, characterised by the appearance of local self-sustained high currents, presumably originating from impurities induced during chamber production. Very effective, though long, recovery procedures were implemented with a HV training of the gaps in situ while taking data. The training allowed most of the affected chambers to be returned to their full functionality and the muon detector efficiency to be kept close to 100%. The possibility of making the recovery faster and even more effective by adding a small percentage of oxygen in the gas mixture has been studied and successfully tested., Comment: 15 pages, 9 figures

Background: Chordoma are malignant tumors of the axial skeleton, which arise from remnants of the notochord. The Notochord (chorda dorsalis) is an essential embryonic structure involved in the development of the nervous system and axial skeleton. Therefore, the notochord seems to be the most biologically relevant control tissue to study chordoma in molecular biology research. Nevertheless, up to now mainly different tissues but not the notochord have been used as control for chordoma, due to difficulty of isolating notochordal tissue. Here, we describe a fast and precise method of isolating notochordal cells.Methods: Examination of human fetuses, with a gestation of 9, 11 and 13 weeks, using (immuno) histochemical methods was performed. To isolate pure notochord cells for further molecular biology investigation five flash frozen fetuses between 9 and 10 weeks of gestation were dissected by microtome slicing. Thereafter pure notochord cells for further molecular biology investigation where harvested by using laser capture microdissection (LCM). RNA was extracted from these samples and used in quantitative PCR.Results: This study illustrates notochord of embryonic spines in three different stages of gestation (9-1113 weeks). Immunohistochemical staining with brachyury showed strong staining of the notochord, but also weak staining of the intervertebral disc and vertebral body. LCM of notochord slices and subsequent total RNA extraction resulted in a good yield of total RNA. qPCR analysis of two housekeeping genes confirmed the quality of the RNA.Conclusion: LCM is a fast and precise method to isolate notochord and the quality and yield RNA extracted from this tissue is sufficient for qPCR analysis. Therefore early embryo notochord isolated by LCM is suggested to be the gold standard for future research in chordoma development, classification and diagnosis. (C) 2016 Elsevier B.V. All rights reserved.

Background: Chordoma are malignant tumors of the axial skeleton, which arise from remnants of the notochord. The Notochord (chorda dorsalis) is an essential embryonic structure involved in the development of the nervous system and axial skeleton. Therefore, the notochord seems to be the most biologically relevant control tissue to study chordoma in molecular biology research. Nevertheless, up to now mainly different tissues but not the notochord have been used as control for chordoma, due to difficulty of isolating notochordal tissue. Here, we describe a fast and precise method of isolating notochordal cells.Methods: Examination of human fetuses, with a gestation of 9, 11 and 13 weeks, using (immuno) histochemical methods was performed. To isolate pure notochord cells for further molecular biology investigation five flash frozen fetuses between 9 and 10 weeks of gestation were dissected by microtome slicing. Thereafter pure notochord cells for further molecular biology investigation where harvested by using laser capture microdissection (LCM). RNA was extracted from these samples and used in quantitative PCR.Results: This study illustrates notochord of embryonic spines in three different stages of gestation (9-1113 weeks). Immunohistochemical staining with brachyury showed strong staining of the notochord, but also weak staining of the intervertebral disc and vertebral body. LCM of notochord slices and subsequent total RNA extraction resulted in a good yield of total RNA. qPCR analysis of two housekeeping genes confirmed the quality of the RNA.Conclusion: LCM is a fast and precise method to isolate notochord and the quality and yield RNA extracted from this tissue is sufficient for qPCR analysis. Therefore early embryo notochord isolated by LCM is suggested to be the gold standard for future research in chordoma development, classification and diagnosis. (C) 2016 Elsevier B.V. All rights reserved.

OBJECTIVE: The aims of the present knee osteoarthritis (KOA)-study were to: (1) describe and compare the changes in magnetic resonance imaging (MRI)-measures of synovitis following an exercise program preceded by an intra-articular injection of either corticosteroid or isotonic saline and (2) investigate if any of the changes in patient reported outcome measures (PROMs) were associated with changes in MRI-measures of synovitis.DESIGN: We performed a randomized, double-blinded, placebo-controlled clinical trial evaluating the effects of intra-articular corticosteroid vs placebo injections given before exercise therapy in KOA-patients. PROMs were assessed using the KOOS (knee injury and osteoarthritis outcome score). Synovitis was assessed on conventional non-contrast-enhanced, conventional contrast-enhanced (CE) and dynamic contrast-enhanced (DCE) MRI. PROMs and MRIs were obtained prior to the intra-articular injection, after termination of the exercise program (week 14-primary time point) and week 26.RESULTS: Of 100 randomized participants (50 in each allocation group), 91 had complete MRI-data at baseline (63% female, mean age: 62 years, median Kellgren-Lawrence-grade: 3). There were no statistically significant differences between the two interventions in regards of changes in MRI-measures of synovitis at any time-point. At week 14, we found no statistical significant MRI-explanatory variables of either of the PROMs.CONCLUSIONS: The present study does not justify the use of intra-articular corticosteroids over intra-articular saline when combined with an exercise program for reduction of synovitis in KOA. The improvement in pain and function following the intervention with intra-articular corticosteroids/saline and exercise could not be explained by a decrease in synovitis on MRI indicating other pain causing/relieving mechanisms in KOA.

OBJECTIVES: To investigate the association between magnetic resonance imaging (MRI), macroscopic and histological assessments of synovitis in end-stage knee osteoarthritis (KOA).METHODS: Synovitis of end-stage osteoarthritic knees was assessed using non-contrast-enhanced (CE), contrast-enhanced magnetic resonance imaging (CE-MRI) and dynamic contrast-enhanced (DCE)-MRI prior to (TKR) and correlated with microscopic and macroscopic assessments of synovitis obtained intraoperatively. Multiple bivariate correlations were used with a pre-specified threshold of 0.70 for significance. Also, multiple regression analyses with different subsets of MRI-variables as explanatory variables and the histology score as outcome variable were performed with the intention to find MRI-variables that best explain the variance in histological synovitis (i.e., highest R2). A stepped approach was taken starting with basic characteristics and non-CE MRI-variables (model 1), after which CE-MRI-variables were added (model 2) with the final model also including DCE-MRI-variables (model 3).RESULTS: 39 patients (56.4% women, mean age 68 years, Kellgren-Lawrence (KL) grade 4) had complete MRI and histological data. Only the DCE-MRI variable MExNvoxel (surrogate of the volume and degree of synovitis) and the macroscopic score showed correlations above the pre-specified threshold for acceptance with histological inflammation. The maximum R2-value obtained in Model 1 was R2 = 0.39. In Model 2, where the CE-MRI-variables were added, the highest R2 = 0.52. In Model 3, a four-variable model consisting of the gender, one CE-MRI and two DCE-MRI-variables yielded a R2 = 0.71.CONCLUSION: DCE-MRI is correlated with histological synovitis in end-stage KOA and the combination of CE and DCE-MRI may be a useful, non-invasive tool in characterising synovitis in KOA.

A method is described which allows to deduce the dead-time of the front-end electronics of the LHCb muon detector from a series of measurements performed at different luminosities at a bunch-crossing rate of 20 MHz. The measured values of the dead-time range from 70 ns to 100 ns. These results allow to estimate the performance of the muon detector at the future bunch-crossing rate of 40 MHz and at higher luminosity.

OBJECTIVE: To investigate the association between knee pain and signs of inflammation in the infrapatellar fat pad (IPFP) in obese patients with knee osteoarthritis (KOA).DESIGN: In a cross-sectional setting, 3-T conventional contrast-enhanced (CE) magnetic resonance imaging (MRI) and dynamic contrast-enhanced (DCE)-MRI of KOA were analysed to quantify the extent of inflammation in the IPFP, and correlated (Spearman's rank correlation) to pain and other symptoms assessed via the Knee injury and Osteoarthritis Outcome Score (KOOS) (100 = no pain, 0 = extreme pain). The extent of inflammation in the IPFP was assessed according to the MRI Osteoarthritis Knee Score (MOAKS) using CE-MRI and by DCE-MRI perfusion variables. The perfusion variable, "Inflammation", was chosen as primary perfusion variable in the analysis. Intraclass correlation coefficients for the perfusion variables ranged from 0.81 to 0.99.RESULTS: MRI and clinical data were obtained in 95 patients. The typical patient was a woman (82%) with an average age of 65 years (SD 6.5) and a body mass index (BMI) of 32 kg/m(2) (SD 3.7). The bivariate association between KOOS pain and the DCE-MRI perfusion variable "Inflammation" showed a statistically significant correlation (r = -0.42, P < 0.0001). A statistically significant correlation was also found between KOOS pain and MOAKS Hoffa-synovitis (r = -0.21, P = 0.046).CONCLUSIONS: Perfusion variables on DCE-MRI reflecting the severity of inflammation in the IPFP and MOAKS Hoffa-synovitis were associated with the severity of pain in KOA. These results suggest that severe inflammation in the IPFP is associated with severe pain in KOA and that DCE-MRI is a promising method to study the impact of inflammation in KOA.

OBJECTIVE: To investigate the association between knee pain and signs of inflammation in the infrapatellar fat pad (IPFP) in obese patients with knee osteoarthritis (KOA).DESIGN: In a cross-sectional setting, 3-T conventional contrast-enhanced (CE) magnetic resonance imaging (MRI) and dynamic contrast-enhanced (DCE)-MRI of KOA were analysed to quantify the extent of inflammation in the IPFP, and correlated (Spearman's rank correlation) to pain and other symptoms assessed via the Knee injury and Osteoarthritis Outcome Score (KOOS) (100 = no pain, 0 = extreme pain). The extent of inflammation in the IPFP was assessed according to the MRI Osteoarthritis Knee Score (MOAKS) using CE-MRI and by DCE-MRI perfusion variables. The perfusion variable, "Inflammation", was chosen as primary perfusion variable in the analysis. Intraclass correlation coefficients for the perfusion variables ranged from 0.81 to 0.99.RESULTS: MRI and clinical data were obtained in 95 patients. The typical patient was a woman (82%) with an average age of 65 years (SD 6.5) and a body mass index (BMI) of 32 kg/m(2) (SD 3.7). The bivariate association between KOOS pain and the DCE-MRI perfusion variable "Inflammation" showed a statistically significant correlation (r = -0.42, P < 0.0001). A statistically significant correlation was also found between KOOS pain and MOAKS Hoffa-synovitis (r = -0.21, P = 0.046).CONCLUSIONS: Perfusion variables on DCE-MRI reflecting the severity of inflammation in the IPFP and MOAKS Hoffa-synovitis were associated with the severity of pain in KOA. These results suggest that severe inflammation in the IPFP is associated with severe pain in KOA and that DCE-MRI is a promising method to study the impact of inflammation in KOA.

Transcatheter aortic valve implantation was first described by Cribier in 2002 [1] and since then has evolved as a routine procedure for high-risk patients with aortic stenosis [2, 3]. As by June 2010, 10,000 transfemoral (TF) implants of the CoreValve™ prosthesis (Medtronic Inc., Minneapolis, MN, USA) and approximately a similar number of TF and transapical (TA) implants of the Edwards Sapien™ prosthesis (Edwards Lifesciences Inc., Irvine, CA, USA) have been reported. While most centers report encouraging procedural results, mid- and long-term data are sparse. No randomized trials have been conducted to prove similar or better outcomes with transfemoral (TF) or transapical (TA) aortic valve implantation (AVI) compared to conventional aortic valve replacement (AVR). Appropriate indications, patient selection and risk assessment, the ideal setting to perform TF/TA-AVI, the involved imaging techniques, and periprocedural treatment are currently under investigation. A high incidence of paravalvular leaks and AV-block, challenges in device positioning, and procedure-related and previously unknown complications have stimulated new design concepts for transcatheter valves that are currently undergoing clinical trials.

The performance of the LHCb Muon system and its stability across the full 2010 data taking with LHC running at ps = 7 TeV energy is studied. The optimization of the detector setting and the time calibration performed with the first collisions delivered by LHC is described. Particle rates, measured for the wide range of luminosities and beam operation conditions experienced during the run, are compared with the values expected from simulation. The space and time alignment of the detectors, chamber efficiency, time resolution and cluster size are evaluated. The detector performance is found to be as expected from specifications or better. Notably the overall efficiency is well above the design requirements, Comment: JINST_015P_1112 2013

The nuclear emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS of 27 GeV average neutrino energy from 1994 to 1997. In total about 100000 charged-current neutrino interactions with at least one identified muon were located in the emulsion target and fully reconstructed, using newly developed automated scanning systems. Charmed particles were searched for by a program recognizing particle decays. The observation of the decay in nuclear emulsion makes it possible to select a sample with very low background and minimal kinematical bias. 2013 charged-current interactions with a charmed hadron candidate in the final state were selected and confirmed through visual inspection. The charm production rate induced by neutrinos relative to the charged-current cross-section is measured to be sigma(nu_mu N -> mu- C X)/sigma(CC) = (5.75 +-0.32 stat +-0.30 syst)%. The charm production cross-section as a function of the neutrino energy is also obtained. The results are in good agreement with previous measurements. The charm-quark hadronization produces the following charmed hadrons with relative fractions (in %): f_Dzero = 43.7+-4.5, f_Lambda_c^plus = 19.2+-4.2, f_Dplus = 25.3+-4.2, and f_D_splus = 11.8+-4.7., Comment: 16 pages, 5 figures

The nuclear emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS of 27 GeV average neutrino energy from 1994 to 1997. In total about 100000 charged-current neutrino interactions with at least one identified muon were located in the emulsion target and fully reconstructed, using newly developed automated scanning systems. Charmed particles were searched for by a program recognizing particle decays. The observation of the decay in nuclear emulsion makes it possible to select a sample with very low background and minimal kinematical bias. 2013 charged-current interactions with a charmed hadron candidate in the final state were selected and confirmed through visual inspection. The charm production rate induced by neutrinos relative to the charged-current cross-section is measured to be sigma(nu_mu N -> mu- C X)/sigma(CC) = (5.75 +-0.32 stat +-0.30 syst)%. The charm production cross-section as a function of the neutrino energy is also obtained. The results are in good agreement with previous measurements. The charm-quark hadronization produces the following charmed hadrons with relative fractions (in %): f_Dzero = 43.7+-4.5, f_Lambda_c^plus = 19.2+-4.2, f_Dplus = 25.3+-4.2, and f_D_splus = 11.8+-4.7., Comment: 16 pages, 5 figures

The LHCb Muon system performance is presented using cosmic ray events collected in 2009. These events allowed to test and optimize the detector configuration before the LHC start. The space and time alignment and the measurement of chamber efficiency, time resolution and cluster size are described in detail. The results are in agreement with the expected detector performance., Comment: Submitted to JINST and accepted

Antineutrino induced electron capture is a resonant process that can have a larg e cross-section for beams of monochromatic antineutrinos. We calculate the cross-section of this process and investigate an experimental setup where monochromatic antineutrinos are produced from the bound-beta decay of fully ionized radioactive atoms in a storage ring. If the energy between the source and the target is well matched, the cross-sections can be significantly larger than the cross-sections of commonly used non-resonant processes. The rate that can be achieved at a small distance between the source and two targets of $10^3$ kg is up to one interaction per $8 .3\cdot10^{18}$ decaying atoms. For a source-target distance corresponding to the first atmospheric neutrino osc illation maximum, the largest rate is one interaction per $3.2\cdot10^{21}$ decaying atoms, provided that extremely stringent monochromaticity conditions ($10^{-7}$ or better) are achieved in future ion beams., Comment: 6 pages, 4 figures, 4 tables

Although the B(s) and Lambda(b) hadrons differ only in the spectator quarks from the well-studied B(d) and B(u) mesons, they provide a unique window on the physics of the b-quark. With no experiments presently running at the Z pole, hadron colliders now provide the best opportunity to study the B(s) and the Lambda(b). The collider experiments at the Tevatron, CDF and D0, have collected large numbers of B(s) and Lambda(b). Some of their latest preliminary measurements are presented here, including masses, lifetimes, and charmless decays. Progress is made toward measuring the lifetime difference Delta Gamma(s) between the B(s) mass eigenstates and the oscillation frequency Delta m(s)., Comment: 11 pages, 5 figures. Proceedings of the XXIV Physics in Collision Conference, June 27-29 2004, Boston. Updated a reference

Although the B(s) and Lambda(b) hadrons differ only in the spectator quarks from the well-studied B(d) and B(u) mesons, they provide a unique window on the physics of the b-quark. With no experiments presently running at the Z pole, hadron colliders now provide the best opportunity to study the B(s) and the Lambda(b). The collider experiments at the Tevatron, CDF and D0, have collected large numbers of B(s) and Lambda(b). Some of their latest preliminary measurements are presented here, including masses, lifetimes, and charmless decays. Progress is made toward measuring the lifetime difference Delta Gamma(s) between the B(s) mass eigenstates and the oscillation frequency Delta m(s)., Comment: 11 pages, 5 figures. Proceedings of the XXIV Physics in Collision Conference, June 27-29 2004, Boston. Updated a reference

Hadron colliders can be an abundant source of heavy flavor quarks, but pose a challenge to isolate the physics signals from the high backgrounds. The upgraded CDF II detector, with its precise tracking capabilities and powerful trigger system, is well equipped for this task. The detector is described with an emphasis on actual performance and on techniques to maximize the heavy flavor yield. Some first heavy flavor results are summarized., Comment: Invited talk at the Workshop on the CKM Unitarity Triangle, IPPP Durham, April 2003 (eConf C0304052). 4 pages LaTeX, 2 eps figures

Hadron colliders can be an abundant source of heavy flavor quarks, but pose a challenge to isolate the physics signals from the high backgrounds. The upgraded CDF II detector, with its precise tracking capabilities and powerful trigger system, is well equipped for this task. The detector is described with an emphasis on actual performance and on techniques to maximize the heavy flavor yield. Some first heavy flavor results are summarized., Comment: Invited talk at the Workshop on the CKM Unitarity Triangle, IPPP Durham, April 2003 (eConf C0304052). 4 pages LaTeX, 2 eps figures

The new CDFII detector incorporates a Time-of-Flight detector (TOF), employing plastic scintillator bars and fine-mesh photomultipliers. Since August 2001 the TOF system has been fully instrumented and integrated into the CDFII data acquisition system. With a design goal of $100 ps$ resolution the TOF system will provide at least two standard deviations separation between $K^{\pm}$ and $\pi^{\pm}$ for momenta $p<1.6 GeV/c$, complementing low momentum particle identification by means of the specific ionization energy loss measured in the drift chamber. We describe the design of the TOF detector and discuss the current status of its calibration and initial performances. Finally we review the expected impact of the TOF detector in the flavor tagging of neutral $B_S$ meson., Comment: Pub. Proceedings Beauty2002, 8th Conference on B-Physics at Hadron machines, presented by S.Giagu (revison: author list updated)

The new CDFII detector incorporates a Time-of-Flight detector (TOF), employing plastic scintillator bars and fine-mesh photomultipliers. Since August 2001 the TOF system has been fully instrumented and integrated into the CDFII data acquisition system. With a design goal of $100 ps$ resolution the TOF system will provide at least two standard deviations separation between $K^{\pm}$ and $\pi^{\pm}$ for momenta $p<1.6 GeV/c$, complementing low momentum particle identification by means of the specific ionization energy loss measured in the drift chamber. We describe the design of the TOF detector and discuss the current status of its calibration and initial performances. Finally we review the expected impact of the TOF detector in the flavor tagging of neutral $B_S$ meson., Comment: Pub. Proceedings Beauty2002, 8th Conference on B-Physics at Hadron machines, presented by S.Giagu (revison: author list updated)

The report describes the measurement of shear modulus and damping of epoxy resin samples undirectionally reinforced with silica fibers. The measurements were performed over a temperature range including the glass-rubber transition of the resin on samples cut with fibers at various angles to the specimen axis. Fiber concentrations up to 74% were used. The report presents a theory of fracture of unidirectional fiber reinforced materials in which the rate at which elastic energy, released by fiber breakage, can be absorbed, is calculated. Analogies of fiber reinforcement theory and chain fracture theories in polymers are discussed. (Author Modified Abstract)