98 research outputs found

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

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    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 s=900\sqrt{s} = 900 GeV with ALICE at the LHC

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    The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at s=900\sqrt{s} = 900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (η<0.8)(|\eta|<0.8) over the transverse momentum range 0.15<pT<100.15<p_{\rm T}<10 GeV/cc. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for η<0.8|\eta|<0.8 is <pT>INEL=0.483±0.001\left<p_{\rm T}\right>_{\rm INEL}=0.483\pm0.001 (stat.) ±0.007\pm0.007 (syst.) GeV/cc and \left_{\rm NSD}=0.489\pm0.001 (stat.) ±0.007\pm0.007 (syst.) GeV/cc, respectively. The data exhibit a slightly larger <pT>\left<p_{\rm T}\right> than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET.Comment: 20 pages, 8 figures, 2 tables, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/390

    The ALICE experiment at the CERN LHC

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    ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 161626 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008

    Surgical treatment of right middle lobe syndrome in children

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    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 pilot study of Helicobacter pylori genotypes and cytokine gene polymorphisms in reflux oesophagitis and peptic ulcer disease

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    WOS: 000335542500007PubMed: 24797597Helicobacter pylon causes various diseases such as chronic gastritis, peptic ulcer and gastric cancer. While majority of the people infected with H. pylori is asymptomatic, 15-20 % of them develop such diseases. the main factors, which determine the development of H. pylori related diseases might be bacterial virulence, host genetic and environmental factors. the aim of this study was to reveal the factors that play a role in the disease development in patients with reflux esophagitis and peptic ulcer, infected with Helicobacter pylori. Environmental factors such as medical agents, smoking and body mass index were evaluated. the factors specific to bacteria such as vacA, CagA, babA and iceA virulence genotypes and the host factors such as IL-1, IL-2, IL-4, IL-6, IL-10, IL-12, interferon-gamma, TNF-alpha, ve TGF-beta(1) gene polymorphisms were compared between the two groups. H. pylori infected twenty five patients with reflux esophagitis and peptic ulcer were enrolled in the study. There was no statistical difference between the two groups regarding environmental factors. IL-2-330T+166T (p=0.037) and IL10 -1082A; -819C (p=0.049) gene polymorphisms were significantly more common in the group of patients with peptic ulcer compared to the group with reflux esophagitis. in both groups of patients, either with reflux esophagitis or, peptic ulcer, multiple H. pylori virulence genotypes (cagA, vacA, babA) (mean values 74 %, 78%, 54% respectively) were observed. in this study, we revealed that cytokine gene polymorphisms may play a role in the development peptic ulcer while H. pylori virulence genotypes seem to be crucial for the development of associated diseases (Tab. 4, Ref. 51). Text in PDF www.elis.sk.Karadeniz Technical UniversityKaradeniz Technical University [2007.114.003.3.]Karadeniz Technical University research fund and identification number is 2007.114.003.3

    Superoxide dismutase activity and the effects of NBQX and CPP on lipid peroxidation in experimental spinal cord injury

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    The endogenous activity of the neuroprotective enzyme superoxide dismutase (SOD) and the amount of lipid peroxidation in the early phase of experimental spinal cord injury, together with the effects of N-methyl-D-aspartate (NMDA) antagonist CPP and non-NMDA antagonist NBQX on lipid peroxidation were evaluated. The clip compression model was used for the production of a standardized spinal cord trauma. SOD activity and malondialdehyde (MDA) levels - as an indicator of lipid peroxidation - were determined in the injured segment of the spinal cord 30 and 60 min after injury. SOD activity did not change in this period, whereas MDA levels at 30 and 60 min after trauma were significantly elevated. Intrathecal administration of CPP or NBQX 15 min after injury produced statistically significant reductions in MDA elevation 60 min after injury. NBQX was found to be more effective than CPP. These results demonstrated that intrathecal local application of excitatory amino acid receptor antagonists can protect the spinal cord from secondary damage caused by the generation of lipid peroxides in experimental spinal cord injury

    Superoxide dismutase activity and the effect of N-methly-D-aspartate antagonists on lipid peroxidation in the early phase of cold injury

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    Free radicals, lipid peroxidation and excitatory amino acids have been implicated in the secondary mechanisms of traumatic brain injury. We used the cold injury model in rats to assess the endogenous activity of the protective enzyme superoxide dismutase (SOD) and the lipid peroxidation level in the contused tissue at an early phase of injury. Furthermore, we treated the rats with two different N-methyl-D-aspartate receptor antagonists, namely MK-801 and CPP, and evaluated their effect on lipid peroxidation in the contused tissue. Rats were divided into four groups: sham, control, treatment 1 and treatment 2 groups (n = 16 for each group). Thirty and 60 min after craniectomy or injury, tissue samples were removed. SOD activity didn't change in this period. However, lipid peroxidation in terms of malondialdehyde (MDA) amount showed a significant increase at 60 min. Fifteen minutes after injury, MK-801 (1 mg/kg), CPP (10 mg/kg) or saline (1 ml) were applied intraperitoneally in treatment 1, treatment 2 and the control groups, Treatment with MK-801 attenuated MDA levels, whereas treatment with CPP did not. The protective effect of MK-801 achieved statistical significance. These results demonstrate that SOD activity does not change in the Parry period of cold injury. Moreover, these results show that lipid peroxidation increases after 60 min of cold injury, and treatment with MK-801 15 min after injury can prevent this elevation
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