144 research outputs found

    Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

    Get PDF
    37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe

    Transverse momentum spectra of charged particles in proton-proton collisions at root s=900 GeV with ALICE at the LHC

    Get PDF
    -The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at root s = 900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (vertical bar eta vertical bar (INEL) = 0.483 +/- 0.001 (stat.) +/- 0.007 (syst.) GeV/c and (NSD) = 0.489 +/- 0.001 (stat.) +/- 0.007 (syst.) GeV/c, respectively. The data exhibit a slightly larger than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET

    First proton-proton collisions at the LHC as observed with the ALICE detector: measurement of the charged-particle pseudorapidity density at root s=900 GeV

    Get PDF
    On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range vertical bar eta vertical bar S collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase

    First proton-proton collisions at the LHC as observed with the ALICE detector: measurement of the charged-particle pseudorapidity density at root s=900 GeV

    Get PDF
    -On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range vertical bar eta vertical bar S collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase

    Complications of Hydatid Cysts in the Lung

    No full text

    Surgical treatment of right middle lobe syndrome in children

    No full text
    Objective: Right middle lobe syndrome is a rare entity in children, causing high morbidity. Our experience of these patients including their clinical and laboratory characteristics, indications forsurgical management, postoperative courses, and follow-up results was evaluated. Methods: A retrospective analysis was performed involving 20 children with right middle lobe syndrome who were hospitalized and treated with surgical resection of the right middle lobe in Van Training and Research Hospital and Yüzüncüyil university hospital, Turkey, between January 2002 and January 2011. Results: The mean age of the patients was 10.5 years (range, 5 to 15 years). Twelve patients were boys and eight were girls. The most frequent symptom was chronic cough (75%). Hemoptysis was present in two (10%) patients. One patient was being treated for asthma. 25% positive cultures were identified among the patients. Streptococcus pneumoniae was the most frequently identified agent in sputum. All patients underwent chest computed tomography. There were bronchiectasis in 11 (55%) patients, atelectasis and bronchiectasis in five (25%) patients, and destroyed lung in four (20%) patients. A narrowed middle lobe bronchus was shown in 15 (75%) patients. Bronchoscopy was performed in 18 (90%) patients. Stenosis due to external compression was seen in 12 (60%) patients, hyperemia and bronchitis in two (10%) patients, granulation tissue in two (10%) patients, and dense secretions in two (10%) patients. A history of doctor-diagnosed tuberculosis was present in two (10%) patients. These patients had completed antituberculous treatment. The patients had been symptomatic for the last 1 to 10 years (mean, 4 years) and had received several medical treatments. All patients (totally 20 patients) underwent right middle lobe resection. In one patient, a bronchial abnormality was found intraoperatively. One patient died on postoperative day 10 due to a brain abscess. Three other patients had postoperative complications (15%). Mean duration of follow-up of the patients was 4.5 years (range, 2 months to 12 years). Seventeen patients were asymptomatic, and two patients had improved. Conclusions: Children with right middle lobe syndrome unresponsive to medical treatment should undergo early lobe resection to avoid serious complications and the progression of the disease to other segments or lobes

    A novel screening test for esophageal squamous cell carcinoma: sirtuin-3

    No full text
    OBJECTIVE: Human sirtuin-3, a protein involved in the mediation of tumors, has been shown to be present in malignancies. The goal of this study was to measure serum sirtuin-3 levels in esophageal squamous cancer cells and to determine whether sirtuin-3 may possess predictive value in advanced cases of esophageal squamous cell carcinoma (ESCC)

    Antioxidant effect of beta-carotene in cystic fibrosis and bronchiectasis: clinical and laboratory parameters of a pilot study

    No full text
    The carotenoids are potent antioxidants with the ability to quench singlet oxygen and other toxic oxygen species. The aim of this pilot study was to investigate the protective effect of beta-carotene on oxidant system in patients with cystic fibrosis (CF) and in patients with bronchiectasis (BE) caused by a reason other than CF. Eighteen children with CF and 15 children with BE followed in the Pediatric Chest Disease Unit of Hacettepe University, and 15 healthy children participated in the study. Compared with the controls, significantly lower plasma levels of beta-carotene were found in the CF group and significantly lower plasma levels of vitamin E in the CF and BE groups. The standardization of carotenoid levels for total cholesterol did not significantly attenuate these differences. In addition, there were significantly higher levels of malondialdehyde (a marker of lipid peroxidation) and tumour necrosis factor-alpha (TNF-alpha) in children with CF and in children with BE than in normal subjects. After 6 mo of beta-carotene supplementation, the plasma levels of beta-carotene and vitamin E increased and the plasma levels of TNF-alpha and malondialdehyde decreased in both groups
    corecore