Performance of the CMS muon system in LHC Run-2 Battilana, C.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
Odprti dostop
The CMS muon system has played a key role for many physics results obtained from the LHC Run-1 and Run-2 data. It presently consists of three detector technologies equipping different regions of the ...spectrometer. Drift Tube chambers (DT) are installed in the CMS muon system barrel, while Cathode Strip Chambers (CSC) cover the CMS end-caps; both serve as tracking and triggering detectors. Moreover, Resistive Plate Chambers (RPC) complement DT and CSC in barrel and end-caps respectively and are mostly used in the trigger. Finally, Gas Electron Multiplier (GEM) chambers are going to be installed in the muon spectrometer endcaps at different stages of the CMS upgrade programme. A slice test consisting of 10 GEM chambers is being presently operated in parallel to the rest of the muon spectrometer. The performance of the different muon detectors and the muon trigger, evaluated using data collected at 13 TeV centre-of-mass energy during the LHC Run2, will be presented in this report in all of its aspects.
We have analyzed the efficiency with which p-amino-hippuric acid (PAH) is extracted (EPAH) by patients with healthy kidneys (n = 13) or kidneys damaged by chronic cyclosporin nephropathy (n = 21) or ...primary glomerulopathy (n = 12); respective values (mean +/- SE) for EPAH were 0.87 +/- 0.03, 0.77 +/- 0.03, and 0.69 +/- 0.04. Judged by a 131I-hippuran-to-PAH clearance ratio of 0.75 +/- 0.05, extraction ratio of hippuran was less efficient than EPAH in three glomerulopathic patients. A direct relationship was defined between EPAH and glomerular filtration rate (GFR) (r = 0.54) or calculated efferent oncotic pressure (IIE; r = 0.41, P less than 0.01). Curve fitting by means of quadratic spline functions revealed GFR and IIE to be additive in predicting EPAH (R2 = 0.45). Linear model prediction methods and a sample reuse technique failed to predict EPAH reliably from GFR and preglomerular oncotic pressure (IIA); however, 95% prediction intervals exceed 0.30 EPAH units in width. We conclude that oncotic pressure (presumably reflecting albumin concentration) along with GFR is predictive of EPAH depression in humans with chronic renal disease. However, even sophisticated curve-fitting techniques are too imprecise for accurate prediction of EPAH in a given individual. We submit that renal venous sampling to determine EPAH continues to be necessary for the accurate determination of the rate of plasma flow in the injured human kidney.
The CMS muon barrel drift tubes system commissioning Abbiendi, G.; Amapane, N.; Battilana, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2009, 2009-1-00, Letnik:
598, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CMS muon barrel drift tubes system has been recently fully installed and commissioned in the experiment. The performance and the current status of the detector are briefly presented and discussed.
We report the pharmacokinetic parameters of ceftriaxone in 11 patients on hemodialysis with end-stage renal disease (ESRD; creatinine clearance less than 5 ml/min/1.73 m2). The patients were studied ...during the interdialysis period and during 4 h of hemodialysis. The mean age was 53.4 years. After the administration of 1 g of ceftriaxone during a constant intravenous infusion over a 30-min period, t 1/2 was 16.6 h, beta was 0.0418 +/- 0.0106 h-1, VD was 14.5 +/- 3.0 liters/1.73 m2 and Clp was 0.40 +/- 0.05 liters/h for the interdialysis period. Hemodialysis started 24 h after the infusion. The initial plasma ceftriaxone concentration was 68.6 +/- 10.8 micrograms/ml. This value dropped to 40.4 +/- 4.7 micrograms/ml at the end of the 4th hour, indicating a significant 41% decay in blood levels during hemodialysis (p less than 0.001). The t 1/2 decreased to 4.88 h, kel rose to 0.142 +/- 0.0250 h-1 and Clp increased to 1.73 +/- 0.44 liters/h. All values were highly significantly different (p less than 0.001) from those during the interdialysis period. The plasma ceftriaxone concentration of 40.4 +/- 4.7 micrograms/ml at the end of hemodialysis was well within the therapeutic range of the drug. We conclude that ceftriaxone has a moderated increase in t 1/2 in patients with ESRD. Ceftriaxone is significantly dialyzable, however, the plasma concentrations are in the therapeutic range by the end of a 4-hour hemodialysis, 28 h after the administration of the drug. We propose that 1 g given intravenously before each hemodialysis will be sufficient to keep the patient's plasma concentrations within the therapeutic range until the next hemodialysis.
Recently we demonstrated potassium secretion by the pars recta or by the descending limb of the juxtamedullary nephron. The purpose of this present investigation is to study the effect of a chronic ...high-potassium intake on this phenomenon. Fractional reabsorption of water and sodium by the juxtamedullary proximal nephron was decreased when compared to that in normal hydropenic rats. There was a striking increase in the fraction of filtered potassium at the end of the juxtamedullary descending limb from 94+/11% to 180+/18%, which was principally a result of enhanced potassium secretion. When the concentration of potassium in the collecting tubule fluid of potassium-loaded rats was reduced after the administration of amiloride, a sharp fall was observed in the amount of potassium which reached the end of the descending limb (64+/8%). A direct correlation was observed between the fraction of filtered potassium at the descending limb and the potassium concentration in the final urine (P less than 0.001). The findings suggest that potassium, like urea, normally undergoes medullary recycling, which is enhanced by chronic potassium loading.
Two drift tubes (DTs) chambers of the CMS muon barrel system were exposed to a 40
MHz bunched muon beam at the CERN SPS, and for the first time the whole CMS Level-1 DTs-based trigger system chain ...was tested. Data at different energies and inclination angles of the incident muon beam were collected, as well as data with and without an iron absorber placed between the two chambers, to simulate the electromagnetic shower development in CMS. Special data-taking runs were dedicated to test for the first time the Track Finder system, which reconstructs track trigger candidates by performing a proper matching of the muon segments delivered by the two chambers. The present paper describes the results of these measurements.
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