184 research outputs found

    Laboratory findings in psoriatic arthritis.

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    Psoriatic arthritis (PsA) has been classically defined as an inflammatory arthritis associated with psoriasis. However, in comparison with other relevant inflammatory arthropathies, in which a definite diagnosis is frequently possible only by means of laboratory investigations, in PsA true laboratory diagnostic markers are lacking. Some markers are utilised more to differentiate other diseases than to characterise PsA. For example in polyarticular PsA, which may be in some cases indistinguishable from RA, the rheumatoid factor (RF) or the more specific and recently introduced antibodies to cyclic citrullinated peptides (anti-CCP), may be useful to better identify RA. However, RF was found in 5% to 13% of patients with PsA, and anti-CCP may be observed in almost similar percentage. The determination of ESR and/or CRP is frequently disappointing in PsA, since they are both elevated in only half of the patients with PsA. However, ESR and/or CRP are included in the most utilised response criteria for RA, such as ACR and DAS, and, in addition are also considered reliable in the assessment of PsA. Furthermore, elevated levels of ESR have been proposed as one of the best predictors of damage progression and, in addition, a low ESR seems protective, while an ESR >15 mm/h is one of the factors associated with an increased mortality in PsA. The synovial fluid (SF) effusion is much higher in PsA, in comparison with other arthropathies. When available, SF analysis may offer additive information useful for the diagnosis, such as the increased number of leukocytes, which underlines the inflammatory nature of the effusion even in a patient with normal serum levels of acute phase response. We found that elevated IL-1 levels in SF of patients with early disease (<6 months), may be predictive of an evolution in polyarticular form at follow-up. This observation is in keeping with the crucial role that inflammatory cytokines play in PsA, probably related to a genetic predisposition. The recent introduction in PsA of anti-TNF-α agents and the demonstration of their efficacy in the management of many clinical disease expressions including peripheral arthropathy, axial involvement, enthesopathy and skin manifestations, have stimulated the research also in the field of the possible laboratory markers. Key words: Psoriatic arthritis, laboratory investigations arthriti

    Decay Constants of Heavy-Light Mesons

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    The decay constants of the heavy-light pseudoscalar mesons are studied in a high statistics run using the Wilson action at β=6.0\beta=6.0 and β=6.2\beta=6.2, and the clover action at β=6.0\beta=6.0. The systematics of O(a)O(a) discretisation errors are discussed. Our best estimates of the decay constants are: fDf_D = 218(9) MeV, fD/fDsf_D/f_{Ds} = 1.11(1) and we obtain preliminary values for fBf_B.Comment: at the Dallas Lattice Conference, October 1993. 3 pages in a single postscript file, uuencoded form. Rome Preprint 93/98

    Quenched BKB_K-parameter with the Wilson and Clover actions at β=6.0\beta = 6.0

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    We present results for the Kaon BB parameter from a sample of 200200 configurations using the Wilson action and 460460 configurations using the Clover action, on a 183×6418^3 \times 64 lattice at β=6.0\beta=6.0. A slight improvement of the chiral behaviour of BKB_K is observed due to the Clover action. We have also compared the results for BKB_K obtained from two different procedures for the boosting of the coupling constant gg. We observe a strong dependence of BKB_K on the prescription adopted for gg in the Wilson case, contrary to the results of the Clover case which are almost unaffected by the choice of gg. Combining some recently obtained non perturbative estimates for the renormalisation constants with our Clover matrix element, we observe a significant improvement in the chiral behaviour of BKB_K.Comment: 3 pages, Latex, Postscript file with figures available at ftp://hpteo.roma1.infn.it/pub/preprints/lat94/donini ; to appear in Lattice '94, Nucl. Phys. (Proc.Suppl.

    Insertion Magnets

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    Chapter 3 in High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary Design Report. The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its luminosity (rate of collisions) by a factor of five beyond the original design value and the integrated luminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely optimised machine so this upgrade must be carefully conceived and will require about ten years to implement. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting magnets, compact superconducting cavities for beam rotation with ultra-precise phase control, new technology and physical processes for beam collimation and 300 metre-long high-power superconducting links with negligible energy dissipation. The present document describes the technologies and components that will be used to realise the project and is intended to serve as the basis for the detailed engineering design of HL-LHC.Comment: 19 pages, Chapter 3 in High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary Design Repor

    Power Test of the First Two HL-LHC Insertion Quadrupole Magnets Built at CERN

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    The High-Luminosity project (HL-LHC) of the CERN Large Hadron Collider (LHC), requires low β* quadrupole magnets in Nb3_3Sn technology that will be installed on each side of the ATLAS and CMS experiments. After a successful shortmodel magnet manufacture and test campaign, the project has advanced with the production, assembly, and test of full-size 7.15- m-long magnets. In the last two years, two CERN-built prototypes (MQXFBP1 and MQXFBP2) have been tested and magnetically measured at the CERN SM18 test facility. These are the longest accelerator magnets based on Nb3_3Sn technology built and tested to date. In this paper, we present the test and analysis results of these two magnets, with emphasis on quenches and training, voltage-current measurements and the quench localization with voltage taps and a new quench antenna

    A lattice study of the exclusive BKγB \to K^* \gamma decay amplitude, using the Clover action at β=6.0\beta=6.0

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    We present the results of a numerical calculation of the BKγB\to K^* \gamma form factors. The results have been obtained by studying the relevant correlation functions at β=6.0\beta=6.0, on an 183×6418^3 \times 64 lattice, using the O(a){\rm O(a)}-improved fermion action, in the quenched approximation. From the study of the matrix element we have obtained the form factor T1(0)T_1(0) which controls the exclusive decay rate. The results are compared with the recent results from CLEO. We also discuss the compatibility between the scaling laws predicted by the Heavy Quark Effective Theory (HQET) and pole dominance, by studying the mass- and q2q^2-dependence of the form factors. From our analysis, it appears that the form factors follow a mass behaviour compatible with the predictions of the HQET and that the q2q^2-dependence of T2T_2 is weaker than would be predicted by pole dominance.Comment: 17 pages, LaTeX + epsf.sty. Uuencoded, compressed, tar archive including the text and one postscript figur

    The LHC Injection Tests

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    A series of LHC injection tests was performed in August and September 2008. The first saw beam injected into sector 23; the second into sectors 78 and 23; the third into sectors 78-67 and sectors 23-34-45. The fourth, into sectors 23-34-45, was performed the evening before the extended injection test on the 10th September which saw both beams brought around the full circumference of the LHC. The tests enabled the testing and debugging of a number of critical control and hardware systems; testing and validation of instrumentation with beam for the first time; deployment, and validation of a number of measurement procedures. Beam based measurements revealed a number of machine configuration issues that were rapidly resolved. The tests were undoubtedly an essential precursor to the successful start of LHC beam commissioning. This paper provides an outline of preparation for the tests, the machine configuration and summarizes the measurements made and individual system performance

    A High Statistics Lattice Calculation of fBstaticf^{static}_B at β=6.2\beta=6.2 Using the Clover Action

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    We present a calculation of fBf_B in the static limit, obtained by numerical simulation of quenched QCD, at β=6.2\beta=6.2 on a 183×6418^3 \times 64 lattice, using the SW-Clover quark action. The decay constant has been extracted by studying heavy(static)-light correlation functions of different smeared operators, on a sample of 220 gauge field configurations. We have obtained fBstatic=(290±15±45)f_B^{static}=(290 \pm 15 \pm 45) MeV, where the first error comes from the uncertainty in the determination of the matrix element and the second comes from the uncertainty in the lattice spacing. We also obtain MBsMBd=(70±10)M_{B_s}-M_{B_d}= (70 \pm 10) MeV and fBsstat/fBdstat=1.11(3)f^{stat}_{B_s}/f^{stat}_{B_d}=1.11(3). A comparison of our results with other calculations of the same quantity is made.Comment: 12 pages, LaTex, 3 figs. (figures not included; available upon request from [email protected]) ROME prep. 94/981, 18 February 199

    Qualitative and quantitative HIV antibodies and viral reservoir size characterization in vertically infected children with virological suppression

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    Background: Absence of detectable viraemia after treatment cessation in some vertically HIV-infected (VHIV) children suggests that early initiation of HAART could lead to functional cure. Objectives: We described the factors associated with HIV antibody levels and the viral reservoir size in HAART-treated VHIV children. Methods: Study included 97 VHIV children with virological suppression, in Bamako, Mali. The anti-gp41 antibody activities and HIV serostatus were assessed. The viral reservoir size was measured by quantifying total cell-associated HIV DNA. Results: Among the children studied, the median total HIV DNA level was 445 copies/106 cells (IQR = 187–914) and the median anti-gp41 antibody activity was 0.29 OD (IQR = 0.18–0.75). Low activity of anti-gp41 antibodies was associated with a younger age of HAART initiation (P = 0.01). Overall, eight HIV-1 seroreversions were identified. Conclusions: Study identified potential candidates with low viral reservoir and low antibody levels or activities for future trials aiming to reduce HIV-1 reservoir to limit HAART duration
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