1,787 research outputs found

    Increased cerebrospinal fluid levels of cytokines monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1β (MIP-1β) in patients with amyotrophic lateral sclerosis

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    Introduction: Neuroinflammation has recently been described in amyotrophic lateral sclerosis (ALS). However, the precise role of such proinflammatory cytokines as monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1� (MIP-1�) in ALS has not yet been determined. In this study, we determined cerebrospinal fluid (CSF) MCP-1 and MIP-1� levels and assessed their association with the duration and severity of ALS. Methods: Concentrations of MCP-1 and MIP-1� were determined in the CSF of 77 patients diagnosed with ALS and 13 controls. Cytokine levels were analysed in relation to ALS duration ( 12 months) and severity ( 30 points on the ALS Functional Rating Scale administered at hospital admission). Results: Higher CSF MIP-1� (10.68 pg/mL vs 4.69 pg/mL, P < .0001) and MCP-1 (234.89 pg/mL vs 160.95 pg/mL, P = .011) levels were found in the 77 patients with ALS compared to controls. There were no differences in levels of either cytokine in relation to disease duration or severity. However, we did observe a significant positive correlation between MIP-1� and MCP-1 in patients with ALS. Conclusions: The increase in MIP-1� and MCP-1 levels suggests that these cytokines may havea synergistic effect on ALS pathogenesis. However, in our cohort, no association was found witheither the duration or the clinical severity of the disease

    Incremento de las citoquinas proteína quimiotáctica de monocitos-1 (MCP-1) y proteína inflamatoria macrofágica-1β (MIP-1β) en líquido cefalorraquídeo de pacientes con esclerosis lateral amiotrófica

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    Introducción: En la esclerosis lateral amiotrófica (ELA) se ha descrito recientemente la presencia de neuroinflamación. Sin embargo, no se ha definido el rol de citoquinas proinflamatrorias como la proteína quimiotáctica de monocitos-1 (MCP-1) y la proteína inflamatoria macrofágica-1� (MIP-1�) en ELA. En este estudio evaluamos niveles de MCP-1 y MIP-1� en líquido cefalorraquídeo (LCR), analizando su participación en la duración y gravedad de la ELA. Métodos: En 77 pacientes con ELA definida y 13 sujetos controles, se comparó el nivel de citoquinas MCP-1 y MIP-1� en LCR. Se analizaron estos niveles con relación a la duración de la ELA ( 12 meses) y a la gravedad de esta determinada mediante el puntaje obtenido al ingreso en la escala funcional estratificada de la ELA ( 30 puntos). Resultados: En los 77 pacientes con ELA, se encontraron aumentados los niveles de MIP-1� (4,69 pg/ml vs. 10,68 pg/ml, p < 0,0001) y MCP-1 (160,95 pg/ml vs. 234,89 pg/ml, p = 0,011) en comparación con sujetos controles. No se observó diferencia de los niveles de estas citoquinas con la duración o la gravedad de la enfermedad. Sin embargo, observamos una correlación positiva significativa entre MIP-1� y MCP-1 en pacientes con ELA. Conclusiones: El aumento de MIP-1� y MCP-1 sugiere que estas citoquinas parecen tener unefecto sinérgico en la patogénesis de la ELA. Sin embargo, en nuestra cohorte no se asociaroncon la duración o la gravedad de la ELA

    Material particulado en España: niveles, composición y contribución de fuentes

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    El estudio llevado a cabo en un elevado número de emplazamientos de medida de material particulado (PM) en España ha permitido determinar las importantes variaciones que se producen en los niveles medios de concentración de PM10 y PM2,5 y en su composición química, entre sus distintas regiones geográficas. En diferentes entornos industriales y de tráfico considerados “hotspots”, los niveles medios de PM10 registrados llegan a superar normalmente los valores límite de concentración recomendados. La variabilidad existente entre los distintos emplazamientos de medida en lo que se refiere a niveles de concentración de PM y a la superación de los valores límite de concentración está relacionada con la existencia de distintos patrones, tanto de emisión de las fuentes de material particulado naturales y antropogénicas, como patrones climáticos y de reactividad/ estabilidad de algunas especies presentes en la composición del PM.Este estudio ha sido financiado mediante convenios de colaboración de la Dirección General de Calidad y Evaluación Ambiental del Ministerio de Medio Ambiente y del Plan Nacional de I+D del Ministerio de Educación y Ciencia (CGL2004-05984_C07-02/CLI, REN2001-0659-C03-03), y contratos de investigación respaldados por Comunidades Autónomas de Andalucía, Cataluña, Madrid, y Valencia

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Combined search for the quarks of a sequential fourth generation

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    Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

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    The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

    Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

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    A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu

    Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

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    The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
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