376 research outputs found

    Long-term follow-up of Philadelphia chromosome-positive (Ph+) chronic myeloid leukaemia (CML) in children and adolescents managed at a single institution over a 20-year period

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    Chronic myeloid leukaemia (CML) is rare in childhood. In our Institution we managed 30 consecutive Ph+CML patients aged <18 years, according to our adults’ guidelines. Patients with HLA-identical related donor (RD) underwent stem cell transplant (SCT). Since 1989, patients without RD were systematically treated with -interferon (IFN) (median dosage: 6 MU/day). Of 18/19 evaluable patients, 17 (94.5%) achieved haematologic response (HR), 11/17 (65%) cytogenetic response (CyR), complete (CCyR) in 4 (23.5%). Three patients remain in CCyR, 2 achieved BCR-ABL transcript disappearance. Of 13 patients without CCyR, 5 underwent SCT, 4 switched to STI571, 4 progressed. All patients receiving STI571 in chronic phase (CP) obtained sustained CCyR and 3 a persistent molecular response. 8-year survival among IFN-treated patients, censored or not for subsequent therapies, is 62% and 63%. Overall, 13/30 patients underwent SCT: 5 HLA-identical-RD, 5 matched unrelated donor, 2 mismatched-RD, 1 unrelated mismatched umbilical cord blood. Eight allotransplanted patients (6/6 in 1st CP) are in cytogenetic and molecular remission with 8-year survival of 61% from SCT and 69% from diagnosis. In our 20-year experience, the use of IFN in children without matched RD led to prolonged cytogenetic and molecular responses and long-term survival, without impairing the outcome of subsequent SCT

    Gluino Decay as a Probe of High Scale Supersymmetry Breaking

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    A supersymmetric standard model with heavier scalar supersymmetric particles has many attractive features. If the scalar mass scale is O(10 - 10^4) TeV, the standard model like Higgs boson with mass around 125 GeV, which is strongly favored by the LHC experiment, can be realized. However, in this scenario the scalar particles are too heavy to be produced at the LHC. In addition, if the scalar mass is much less than O(10^4) TeV, the lifetime of the gluino is too short to be measured. Therefore, it is hard to probe the scalar particles at a collider. However, a detailed study of the gluino decay reveals that two body decay of the gluino carries important information on the scalar scale. In this paper, we propose a test of this scenario by measuring the decay pattern of the gluino at the LHC.Comment: 29 pages, 9 figures; version published in JHE

    Discovery Potential for Low-Scale Gauge Mediation at Early LHC

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    Low-scale gauge-mediated supersymmetry(SUSY)-breaking (GMSB) models with gravitino mass m_{3/2}<16 eV are attractive, since there are no flavor and cosmological problems. In this paper, we thoroughly study the collider signal in the case that the next-to-lightest SUSY particle is the bino or slepton and investigate the discovery potential of the LHC. Our result is applicable to a wider class of GMSB models other than the minimal GMSB models and we pay particular attention to realistic experimental setups. We also apply our analysis to the minimal GMSB models with a metastable SUSY-breaking vacuum and we show, by requiring sufficient stability of the SUSY-breaking vacuum, these models can be tested at an early stage of the LHC.Comment: 21 pages, 7 figures.Texts in section 3.2.2 and 3.2.4 are revised. Captions change

    Examining leptogenesis with lepton flavor violation and the dark matter abundance

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    Within a supersymmetric (SUSY) type-I seesaw framework with flavor-blind universal boundary conditions, we study the consequences of requiring that the observed baryon asymmetry of the Universe be explained by either thermal or non-thermal leptogenesis. In the former case, we find that the parameter space is very constrained. In the bulk and stop-coannihilation regions of mSUGRA parameter space (that are consistent with the measured dark matter abundance), lepton flavor-violating (LFV) processes are accessible at MEG and future experiments. However, the very high reheat temperature of the Universe needed after inflation (of about 10^{12} GeV) leads to a severe gravitino problem, which disfavors either thermal leptogenesis or neutralino dark matter. Non-thermal leptogenesis in the preheating phase from SUSY flat directions relaxes the gravitino problem by lowering the required reheat temperature. The baryon asymmetry can then be explained while preserving neutralino dark matter, and for the bulk or stop-coannihilation regions LFV processes should be observed in current or future experiments.Comment: 20 pages, 5 figures, 1 tabl

    Stealth Supersymmetry

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    We present a broad class of supersymmetric models that preserve R-parity but lack missing energy signatures. These models have new light particles with weak-scale supersymmetric masses that feel SUSY breaking only through couplings to the MSSM. This small SUSY breaking leads to nearly degenerate fermion/boson pairs, with small mass splittings and hence small phase space for decays carrying away invisible energy. The simplest scenario has low-scale SUSY breaking, with missing energy only from soft gravitinos. This scenario is natural, lacks artificial tunings to produce a squeezed spectrum, and is consistent with gauge coupling unification. The resulting collider signals will be jet-rich events containing false resonances that could resemble signatures of R-parity violation. We discuss several concrete examples of the general idea, and emphasize gamma + jet + jet resonances, displaced vertices, and very large numbers of b-jets as three possible discovery modes.Comment: 12 pages, 4 figure

    Natural Supersymmetry at the LHC

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    If the minimal supersymmetric standard model is the solution to the hierarchy problem, the scalar top quark (stop) and the Higgsino should weigh around the electroweak scale such as 200 GeV. A low messenger scale, which results in a light gravitino, is also suggested to suppress the quantum corrections to the Higgs mass parameters. Therefore the minimal model for natural supersymmetry is a system with stop/Higgsino/gravitino whereas other superparticles are heavy. We study the LHC signatures of the minimal system and discuss the discovery potential and methods for the mass measurements.Comment: 19 pages, 6 figures, 1 tabl

    The association of impaired semen quality and pregnancy rates in assisted reproduction technology cycles: Systematic review and meta-analysis

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    Some studies suggest a relationship between semen quality and pregnancy rates of assisted reproduction technologies (ART). Others have questioned the utility of semen quality as proxy for fertility in couples attempting to conceive with or without assistance. We aimed to investigate the current body of evidence which correlates semen parameters and clinical pregnancy among couples utilizing ART (i.e. in vitro fertilization [IVF], intracytoplasmic sperm injection [ICSI]) through a systematic review and meta-analysis of cross-sectional and retrospective cohort studies. Pooled Odd Ratio (OR) for oligo-, astheno- and teratospermic compared to normospermic number of ART cycles were calculated among. Meta-regression and sub-group analysis were implemented to model the contribution of clinical/demographic and laboratory standards differences among the studies. Overall, 17 studies were analysed representing 17,348 cycles were analysed. Pooled OR for impaired sperm concentration, motility and morphology was 1 (95%Confidence Interval [CI]: 0.97-1.03), 0.88 (95%CI: 0.73-1.03) and 0.88 (95%CI: 0.75-1) respectively. Further analysis on sperm morphology showed no differences with regard of IVF versus ICSI (p = 0.14) nor a significant correlation with rising reference thresholds (Coeff: -0.02, p = 0.38). A temporal trend towards a null association between semen parameters and clinical pregnancy was observed over the 20-year observation period (Coeff: 0.01, p = 0.014). The current analysis found no association between semen quality (as measured by concentration, motility or morphology) and clinical pregnancy rates utilizing ART. Future investigations are necessary to explore the association between semen parameters and other ART outcomes (e.g. fertilization, implantation, birth and perinatal health)

    Efficacy of three BCG strains (Connaught, TICE and RIVM) with or without secondary resection (re-TUR) for intermediate/high-risk non-muscle-invasive bladder cancers: results from a retrospective single-institution cohort analysis

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    Purpose: (I) To evaluate the clinical efficacy of three different BCG strains in patients with intermediate-/high-risk non-muscle-invasive bladder cancer (NMIBC). (II) To determine the importance of performing routine secondary resection (re-TUR) in the setting of BCG maintenance protocol for the three strains. Methods: NMIBCs who received an adjuvant induction followed by a maintenance schedule of intravesical immunotherapy with BCG Connaught, TICE and RIVM. Only BCG-naïve and those treated with the same strain over the course of follow-up were included. Cox proportional hazards model was developed according to prognostic factors by the Spanish Urological Oncology Group (CUETO) as well as by adjusting for the implementation of re-TUR. Results: n = 422 Ta-T1 patients (Connaught, n = 146; TICE, n = 112 and RIVM, n = 164) with a median (IQR) follow-up of 72 (60-85) were reviewed. Re-TUR was associated with improved recurrence and progression outcomes (HRRFS: 0.63; 95% CI 0.46-0.86; HRPFS: 0.55; 95% CI 0.31-0.86). Adjusting for CUETO risk factors and re-TUR, BGC TICE and RIVM provided longer RFS compared to Connaught (HRTICE: 0.58, 95% CI 0.39-0.86; HRRIVM: 0.61, 95% CI 0.42-0.87) while no differences were identified between strains for PFS and CSS. Sub-analysis of only re-TUR cases (n = 190, 45%) showed TICE the sole to achieve longer RFS compared to both Connaught and RIVM. Conclusion: Re-TUR was confirmed to ensure longer RFS and PFS in intermediate-/high-risk NMIBCs but did not influence the relative single BCG strain efficacy. When routinely performing re-TUR followed by a maintenance BCG schedule, TICE was superior to the other strains for RFS outcomes

    Strong Double Higgs Production at the LHC

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    The hierarchy problem and the electroweak data, together, provide a plausible motivation for considering a light Higgs emerging as a pseudo-Goldstone boson from a strongly-coupled sector. In that scenario, the rates for Higgs production and decay differ significantly from those in the Standard Model. However, one genuine strong coupling signature is the growth with energy of the scattering amplitudes among the Goldstone bosons, the longitudinally polarized vector bosons as well as the Higgs boson itself. The rate for double Higgs production in vector boson fusion is thus enhanced with respect to its negligible rate in the SM. We study that reaction in pp collisions, where the production of two Higgs bosons at high pT is associated with the emission of two forward jets. We concentrate on the decay mode hh -> WW^(*)WW^(*) and study the semi-leptonic decay chains of the W's with 2, 3 or 4 leptons in the final states. While the 3 lepton final states are the most relevant and can lead to a 3 sigma signal significance with 300 fb^{-1} collected at a 14 TeV LHC, the two same-sign lepton final states provide complementary information. We also comment on the prospects for improving the detectability of double Higgs production at the foreseen LHC energy and luminosity upgrades.Comment: 54 pages, 26 figures. v2: typos corrected, a few comments and one table added. Version published in JHE

    Anomalous Couplings in Double Higgs Production

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    The process of gluon-initiated double Higgs production is sensitive to non-linear interactions of the Higgs boson. In the context of the Standard Model, studies of this process focused on the extraction of the Higgs trilinear coupling. In a general parametrization of New Physics effects, however, an even more interesting interaction that can be tested through this channel is the (ttbar hh) coupling. This interaction vanishes in the Standard Model and is a genuine signature of theories in which the Higgs boson emerges from a strongly-interacting sector. In this paper we perform a model-independent estimate of the LHC potential to detect anomalous Higgs couplings in gluon-fusion double Higgs production. We find that while the sensitivity to the trilinear is poor, the perspectives of measuring the new (ttbar hh) coupling are rather promising.Comment: 22 pages, 9 figures. v2: plots of Figs.8 and 9 redone to include experimental uncertainty on the Higgs couplings, references adde
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