Natural history of infrainguinal vein bypass stenoses: Early lesions increase the risk of thrombosis

Objectives:To describe the natural history of stenoses in infrainguinal vein bypasses and to identify factors predicting outcome.Methods:Forty-two patients with non-revised vein bypass stenoses were followed prospectively by ultrasound Duplex scanning and ankle blood pressure measurements.Results:During a median follow-up of 8(range 0–22) months 18(43%) (95% confidence limits 28–59%) bypasses thrombosed and 6(14%) (95% confidence limits 5–29%) patients were amputated. Bypass patency was lower in 12 patients with stenoses associated with reduction in ankle brachial index (ABI) exceeding 0.15 than in 30 patients with no or only marginal reduction in ABI (12 month patency 33% vs. 68%, p = 0.005). Among the 30 patients without distal pressure reduction, stenoses identified within 3 months from surgery were associated with an increased risk of thrombosis as compared to stenoses identified at a later stage (12 month patency 51% vs. 92%, p = 0.03).Conclusion:Time interval from surgery to stenosis detection seems to be an independent parameter influencing outcome in patients with vein bypass stenoses

Early vein bypass thrombectomy is associated with an increased risk of graft related stenoses

Objectives:To assess the risk of graft stenoses following early thrombectomy of peripheral vein bypasses.Design:Prospective study of 371 vein bypasses performed at the Vascular Service, Rigshospitalet, Copenhagen from January 1991 through December 1992.Materials and methods:Thirty-six vein bypasses reopened by thrombectomy within 30 days postoperatively (group I) and 335 bypasses not subjected to early thrombectomy (group II) were studied by ultrasound duplex scanning 3, 6, 9, 12, 18, 24, 36 and 48 months postoperatively. A localised increase in the peak systolic velocity of 250% or more was considered an indicator for significant stenosis.Results:In the perioperative period nine (2%) patients died, 30 (8%) bypasses occluded and 14 (4%) patients were lost to follow-up. Among the 318 patients remaining at risk at 1 month graft stenoses were identified in 39% (9/23) in group I compared to 17% (51/295) in group II, p = 0.03. Late bypass revisions were required in 35% (8/23) in group I as opposed to 9% (28/295) in group II, p = 0.004. Despite this high number of revisional procedures the 12-months secondary bypass patency was lower in recanalised grafts (38% vs. 82%, p < 0.00001).Conclusion:Early vein bypass thrombectomy is associated with a two-fold increased risk of graft related stenoses and a reduced secondary bypass patency

Experimental implementation of a NMR entanglement witness

Entanglement witnesses (EW) allow the detection of entanglement in a quantum system, from the measurement of some few observables. They do not require the complete determination of the quantum state, which is regarded as a main advantage. On this paper it is experimentally analyzed an entanglement witness recently proposed in the context of Nuclear Magnetic Resonance (NMR) experiments to test it in some Bell-diagonal states. We also propose some optimal entanglement witness for Bell-diagonal states. The efficiency of the two types of EW's are compared to a measure of entanglement with tomographic cost, the generalized robustness of entanglement. It is used a GRAPE algorithm to produce an entangled state which is out of the detection region of the EW for Bell-diagonal states. Upon relaxation, the results show that there is a region in which both EW fails, whereas the generalized robustness still shows entanglement, but with the entanglement witness proposed here with a better performance

Liberating Efimov physics from three dimensions

When two particles attract via a resonant short-range interaction, three particles always form an infinite tower of bound states characterized by a discrete scaling symmetry. It has been considered that this Efimov effect exists only in three dimensions. Here we review how the Efimov physics can be liberated from three dimensions by considering two-body and three-body interactions in mixed dimensions and four-body interaction in one dimension. In such new systems, intriguing phenomena appear, such as confinement-induced Efimov effect, Bose-Fermi crossover in Efimov spectrum, and formation of interlayer Efimov trimers. Some of them are observable in ultracold atom experiments and we believe that this study significantly broadens our horizons of universal Efimov physics.Comment: 17 pages, 5 figures, contribution to a special issue of Few-Body Systems devoted to Efimov Physic

Instanton Effects on the Role of the Low-Energy Theorem for the Scalar Gluonic Correlation Function

Instanton contributions to the Laplace sum-rules for correlation functions of scalar gluonic currents are calculated. The role of the constant low-energy theorem term, whose substantial contribution is unique to the leading Laplace sum-rule $L_{-1}$, is shown to be diminished by instanton contributions, significantly increasing the resulting mass bounds for the ground state of scalar gluonium and improving compatibility with results from higher-weight sum-rules.Comment: latex2e, 12 pages, 10 encapsulated postscript figures. Revised version includes additional analysis, figures, and reference

Baseline total metabolic tumor volume is prognostic for refractoriness to Iimunochemotherapy in DLBCL: results from GOYA

Introduction A good response to initial therapy is key to maximizing survival in patients with diffuse large B-cell lymphoma (DLBCL), but patients with chemorefractory disease and early progression have poor outcomes. Patients and Methods Data from the GOYA study in patients with DLBCL who received first-line rituximab or obinutuzumab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) were analyzed. Positron emission tomography/computed tomography (PET/CT)-derived characteristics associated with total metabolic tumor volume (TMTV) and clinical risk factors for primary chemorefractory disease and disease progression within 12 months (POD12) were explored. Results Of those patients fulfilling the criteria for analysis, 108/1126 (10%) were primary chemorefractory and 147/1106 (13%) had POD12. Primary chemorefractory and POD12 status were strongly associated with reduced overall survival. After multivariable analysis of clinical and imaging-based risk factors by backward elimination, only very high TMTV (quartile [Q] 1 vs. Q4 odds ratio [OR]: 0.45; P = .006) and serum albumin levels (low vs. normal OR of 1.86; P = .004) were associated with primary chemorefractoriness. After additionally accounting for BCL2/MYC translocation in a subset of patients, TMTV and BCL2/MYC double-hit status remained as significant predictors of primary chemorefractoriness (Q1 vs. Q4 OR: 0.32, P = .01 and double-hit vs. no-hit OR of 4.47, P = .02, respectively). Risk factors including very high TMTV, high sum of the product of the longest diameters (SPD), geographic region (Asia), short time since diagnosis, extranodal involvement and low serum albumin were retained for POD12. Conclusion PET-derived TMTV has prognostic value in identifying patients at risk of early treatment failure

Near-Maximal Mixing of Scalar Gluonium and Quark Mesons: A Gaussian Sum-Rule Analysis

Gaussian QCD sum-rules are ideally suited to the study of mixed states of gluonium (glueballs) and quark ($q\bar q$) mesons because of their capability to resolve widely-separated states of comparable strength. The analysis of the Gaussian QCD sum-rules (GSRs) for all possible two-point correlation functions of gluonic and non-strange ($I=0$) quark scalar ($J^{PC}=0^{++}$) currents is discussed. For the non-diagonal sum-rule of gluonic and $q\bar q$ currents we show that perturbative and gluon condensate contributions are chirally suppressed compared to non-perturbative effects of the quark condensate, mixed condensate, and instantons, implying that the mixing of quark mesons and gluonium is of non-perturbative origin. The independent predictions of the masses and relative coupling strengths from the non-diagonal and the two diagonal GSRs are remarkably consistent with a scenario of two states with masses of approximately 1 GeV and 1.4 GeV that couple to significant mixtures of quark and gluonic currents. The mixing is nearly maximal with the heavier mixed state having a slightly larger coupling to gluonic currents than the lighter state.Comment: Updated version contains extended analysis and revised analysis methods. 21 pages, 14 figure

Leptogenesis and low energy observables in left-right symmetric models

In the context of left-right symmetric models we study the connection of leptogenesis and low energy parameters such as neutrinoless double beta decay and leptonic CP violation. Upon imposition of a unitarity constraint, the neutrino parameters are significantly restricted and the Majorana phases are determined within a narrow range, depending on the kind of solar solution. One of the Majorana phases gets determined to a good accuracy and thereby the second phase can be probed from the results of neutrinoless double beta decay experiments. We examine the contributions of the solar and atmospheric mass squared differences to the asymmetry and find that in general the solar scale dominates. In order to let the atmospheric scale dominate, some finetuning between one of the Majorana phases and the Dirac CP phase is required. In this case, one of the Majorana phases is determined by the amount of CP violation in oscillation experiments.Comment: 18 pages, 6 figures. Matches version to appear in PR

Lorentz breaking Effective Field Theory and observational tests

Analogue models of gravity have provided an experimentally realizable test field for our ideas on quantum field theory in curved spacetimes but they have also inspired the investigation of possible departures from exact Lorentz invariance at microscopic scales. In this role they have joined, and sometime anticipated, several quantum gravity models characterized by Lorentz breaking phenomenology. A crucial difference between these speculations and other ones associated to quantum gravity scenarios, is the possibility to carry out observational and experimental tests which have nowadays led to a broad range of constraints on departures from Lorentz invariance. We shall review here the effective field theory approach to Lorentz breaking in the matter sector, present the constraints provided by the available observations and finally discuss the implications of the persisting uncertainty on the composition of the ultra high energy cosmic rays for the constraints on the higher order, analogue gravity inspired, Lorentz violations.Comment: 47 pages, 4 figures. Lecture Notes for the IX SIGRAV School on "Analogue Gravity", Como (Italy), May 2011. V.3. Typo corrected, references adde