218 research outputs found

    САХАРНЫЙ ДИАБЕТ И ХИРУРГИЧЕСКОЕ ЛЕЧЕНИЕ ИШЕМИЧЕСКОЙ БОЛЕЗНИ СЕРДЦА

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    Nearly 40-year experience of surgical treatment of coronary heart disease testifies to higher coronary heart disease (CHD) morbidity and mortality rates among diabetes mellitus patients in comparison to non-diabetic patients. At the same time, comparative study of CHD treatment methods efficacy in diabetes mellitus patients has shown that surgery is preferred to angioplasty, especially in the most severe cases – in presence of coronary occlusion, insulin-dependent diabetes and left-ventricle dysfunction. More inferior results of coronary bypass surgery in diabetic patients in comaparison to non-diabetic were conditional on a more pronounced arterial calcinosis and diffuse distal arterial involvement, as well as more severe aortal ateromatosis, flebopathy and more often wound infection occurrence. In the department of cardio-vascular surgery in Russian cardiologic scientific productive complex a quarter of all patients waiting for the coronary bypass surgery are diabetic. Selection algorithm, preoperation preparation, peculiarities of surgical technique and principles of postoperative supervision of these patients were specially designed. With adequate preparation, remission of diabetes and use of microsurgery, postoperative prognosis for these patients (both stratified and real) is comparative to that for the main group of patients. One-year follow up after the bypass surgery data testifies to the low difference in autovenous and autoarterial shunt patency in diabetic and non-diabetic patients. Long-term (10 years) survival rate is significantly lower in the group of diabetic patients. Proposed cardioprotective postoperative strategy is designed to improve both short and long-term efficacy of surgical revascularization in CHD patients with concomitant diabetes mellitus.Почти 40-летный опыт хирургического лечения ИБС свидетельствует о худших показателях заболеваемости и смертности у больных ишемической болезнью сердца (ИБС), страдающих сахарным диабетом (СД), в сравнении с лицами, не страдающими диабетом. В то же время сравнение эффективности различных методов лечения ИБС у больных, страдающих СД, показали явное преимущество хирургии перед ангиопластикой, особенно в наиболее тяжелой группе больных: при окклюзиях коронарных артерий, при инсулинопотребном диабете и при дисфункции левого желудочка. Худшие результаты коронарного шунтирования (КШ) при диабете в сравнении с «недиабетиками» обусловлены более выраженным кальцинозом и диффузным поражением дистальных сегментов артерий, а также более тяжелым атероматозом аорты, флебопатией и более частым развитием раневых инфекций. В Отделе сердечно-сосудистой хирургии РКНПК среди всех кандидатов на КШ четверть составляют больные, страдающие диабетом. Разработаны алгоритм отбора, предоперационной подготовки, особенности хирургической техники и детали послеоперационного ведения этой категории пациентов. При адекватной подготовке, достижении компенсации СД и использовании микрохирургии, прогноз ближайшего послеоперационного периода у них (как стратифицируемый, так и фактический) сравним с основной группой больных. Данные годичной шунтографии свидетельствуют о малых различиях в проходимости аутовенозных и аутоартериальных шунтов у больных с СД и без него. Отдаленные (10 лет) результаты выживаемости после КШ достоверно хуже при диабете. Предложенная кардиопротективная стратегия послеоперационного периода направлена на улучшение как ближайшей, так и отдаленной эффективности хирургической реваскуляризации у больных ИБС с сопутствующим СД

    Single Spin Asymmetry ANA_N in Polarized Proton-Proton Elastic Scattering at s=200\sqrt{s}=200 GeV

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    We report a high precision measurement of the transverse single spin asymmetry ANA_N at the center of mass energy s=200\sqrt{s}=200 GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The ANA_N was measured in the four-momentum transfer squared tt range 0.003t0.0350.003 \leqslant |t| \leqslant 0.035 \GeVcSq, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of ANA_N and its tt-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the single spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated by the Pomeron amplitude at this s\sqrt{s}, we conclude that this measurement addresses the question about the presence of a hadronic spin flip due to the Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure

    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

    Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

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    A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

    Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

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    The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

    Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

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    A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the mass difference between top quark and antiquark in pp collisions at root s=8 TeV

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    Measurement of the Z boson differential cross section in transverse momentum and rapidity in proton-proton collisions at 8 TeV

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    We present a measurement of the Z boson differential cross section in rapidity and transverse momentum using a data sample of pp collision events at a centre-of-mass energy s=8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The Z boson is identified via its decay to a pair of muons. The measurement provides a precision test of quantum chromodynamics over a large region of phase space. In addition, due to the small experimental uncertainties in the measurement the data has the potential to constrain the gluon parton distribution function in the kinematic regime important for Higgs boson production via gluon fusion. The results agree with the next-to-next-to-leading-order predictions computed with the fewz program. The results are also compared to the commonly used leading-order MadGraph and next-to-leading-order powheg generators. © 2015 CERN for the benefit of the CMS Collaboration

    Search for the associated production of the Higgs boson with a top-quark pair

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    A search for the standard model Higgs boson produced in association with a top-quark pair t t ¯ H (tt¯H) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb &#8722;1 and 19.7 fb &#8722;1 collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H &#8594; hadrons, H &#8594; photons, and H &#8594; leptons. The results are characterized by an observed t t ¯ H tt¯H signal strength relative to the standard model cross section, &#956; = &#963;/&#963; SM ,under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is &#956; = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV

    Identification techniques for highly boosted W bosons that decay into hadrons

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